query
string | positive_document
list | negative_document
list | prompt
string | source
string |
|---|---|---|---|---|
What does the 100 emoji represent and why is it so popular?
|
[
" IIRC, it started off as something like the 'top score' of a test in japan, or 100/100 points, usually underlined a time or two to emphasise.\n\n\nThen folks took it to mean something along the lines of 'perfect', 'great', and so on. Brandish the 100? You are saying you're perfect. Call something 100? It's great! And so on, ad nauseum.\n\n\nTL;DR: The 100 emoji is the equivalent of 'really great' or 'perfect', and has about the same sticky memetic quality as YOLO did."
] |
[
" It's a numerical representation of how popular you are.",
" Emojis are like a new letter in the dictionary.\nAll companies show the letter U a little different, and all the companies show the Happy face a little different. \nVery little agreement is necessary.\n\nBold and Italics is adding decoration to your letters, for decoration all the companies involved need to agree in the same exact format and people are dumb dumbs who can never agree on anything. \n\nEdit: Going beyond eli 5.\nAll of the suggestions for text formatting are god awful, as they should be, since no one seems to be a a seasoned engineer, and text encoding is a deceptively complex issue. \nAll of the different suggestions, however, do highlight the main point that getting a group to agree on anything goes towards impossibility as the number of people goes up"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What is the difference between Signal-to-noise ratio and Signal-to-interference ratio?
|
[
" They are virtually the same thing. It is used in the case that the non-signal noise is actually from another radio transmitter (or more than one). \n \nWhen EE's talk about \"noise\" in a radio signal, it is typically random noise from the environment, not another transmitter. There's also \"cross-talk\", which can be noise from conductors inside of a circuit or from a nearby circuit. But sometimes that term is also used for radio interference."
] |
[
" Bigger sensors deal with noise better. Larger pixels mean the signal to noise ratio is larger, so bigger sensors have better low light performance. \n\nI'm sure there are others, but this is the biggest aspect that comes to mind\n\nThe downside being you need larger lenses that project a larger image which means you need better glad which means it costs more",
" Several reasons.\n\n-AM stations are 10khz bandwidth\n\n-FM stations are 200khz bandwidth\n\n-FM radio transmits at a constant output power.\n\n-AM radio transmits at a variable output power. The loudness of a sound is based on how much power (over the carrier) is output. Thus, 'silence' in the audio would use *much* less power and be more suspectible to interference being heard over it.\n\n-Radio receiver designers like to be cheap and consequently they tend to perform better in one mode than the other, using a hack to accomplish the other modes. (using an FM chip and then accomplishing AM using a hack or 'good enough' approach)\n\n-AM is mono, FM is stereo\n\n-Lower frequencies (like AM) have more interference in general, and bounce around the atmosphere more creating 'echos' more than FM.\n\n-AM stations might be doing carrier suppressed dual sideband to reduce their power bill by 1/3rd, but this is a 'hack' to save money at the expense of not actually transmitting AM. During silence there's no carrier for your radio to lock onto or to hear as 'silence'."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why has Socialism such a bad stigma in the U.S.?
|
[
" Socialism has a bad stigma amongst a certain political ideology in the US. Mainly conservatives who do not want their posessions redistributed to society, regardless of the net benefit to their population.\n\nHealthcare and education are examples of public goods with lots of spillover benefits. We have sort of socialized education with public schools and educational requirements. We have also sort of socialized medicine with Medicare. People hate having to pay high taxes to fund Medicare and education, and so there is always a political battle to defund social programs, under the theory that the money should be given back to the citizens earning it, and they will spend it how they want. This causes issues because humans are not very good at planning for the future, so instead of saving money for future education or for a possible medical fiasco, they spend it on other things, some necessities and others luxuries.\n \nNow, personallys peaking, I work entirely with conservatives. They have this mentality of every-man-for-himself even when presented with evidence that the benefits cooperation exceed those of competition. I just consider them to be greedy fucks who would want an extra dollar in their pocket even if it means a single mother supporting her children gets thrown out on the street and starves to death because her federal assistance was taken away. I've actually gotten one of them to admit as much."
] |
[
" If this is in regards to workers unions, it's because America has been so vehemently anti-socialism because of the Cold War that anything which has the slightest association with socialism is automatically stigmatised, despite how much they may benefit many of the people who are against them (access to affordable or free healthcare, workers unions, maternity leave, paid vacation time for workers, etc.)",
" The cold war has left a constant negative connotation with the word 'socialism' in the United States. During the entirety of the cold war the communist or socialist republic was seen as an enemy and this resentment has remained. \n\nFollowing this many collectivist or 'socialist' ideas are berrated in a negative light.\n\nThe interesting thing is the number of socialist programs that are currently in operation in the USA, the welfare and food stamp program being a great example, the American welfare system is one of the largest in the world.\n\nHowever, since it is American grown it is not viewed in the American colloquial socialism.\n\nTLDR While many socialist programs in the United States exist, the word 'socialism' is mainly interepted as anti-American, wrong or negative."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How is Elon Musk's The Boring Company allowed to start boring tunnels under LA? I know they need permits from Bureau of Engineering but this is something that affects every resident, why isn't this a joint private/city project with local government oversight?
|
[
" When you own land you only own a few feet into the ground and about 30-40 feet into the air. If you own mineral rights you own deeper but few people in cities own mineral rights. What this means is that once you go deep enough it is the Government that owns and controls that space and they are the ones that give permission for all activity done there. \n\nAnd the Boring Company getting their permits is them dealing with the local government."
] |
[
" In THEORY this would be impossible because:\nThe value of ALL of the privately owned land in a large city would be more than any private company (even the biggest) could afford. That would still leave public land that would need to be acquired - which would likely prove even more difficult, especially if the company's intentions were perceived to be less than magnanimous. On top of that, there would still need to be a democratically elected government/city council representative of the people - which is something that is outlined by City Charters, State Constitutions, and the U.S. Constitution. Even if you were able to buy up all of the land, utilities etc...of a major city (highly unlikely) - the risk would be tremendous. At the end of the day - the people are the sovereign, and eventually they could start doing things like using Eminent Domain to seize private property to be used for public good. If said company was perceived to be operating in the best interests of shareholders and NOT the best interests of city residents - it wouldn't take much for populist sentiment to lead to such seizures, making the initial investment a very risky one.\n\nIn PRACTICE no private company would do this because:\nCities that are cash-strapped and struggling have historically been highly open to public/private partnerships that give away sweetheart deals to private companies. They typically come in the form of tax credits or subsidies for Company X to build a new plant, or offices in the city or state. Also, private universities have historically also made a killing on deals like this (Johns Hopkins is one of the biggest landowners in Baltimore City, a struggling metropolitan area similar to Detroit). For years Hopkins has acquired land in Baltimore at dirt cheap and subsidized prices. \n\nTL;DR Companies can already receive taxpayer subsidized deals to own land/operate businesses in a city. And they can do so without the headaches that would come from actually owning the entirety of a city.",
" My dad is a project manager for a developer. I asked him this question a few weeks ago. Here's what he said:\n\nI would think it is a combination of a lot of the items the article mentioned plus many other items. There is a current lack of skilled labor which is forcing contractors to work overtime to complete projects. Also, our government regulations and review, paperwork processes keeps getting worse. The states control many of these projects but they have to meet federal guidelines to get federal funds. Double government control. Double the paperwork to get plans approved and get paid. Doesn’t help. (I have a small project right now for 1000’ of new city sewer. I need Delaware City, Delaware County, Orange Township, Army Corp of Engineers, and OhioEPA approval. And I’m paying for the work, no government funds.)\n\n \n\nOne thing that was mentioned many years ago. Public projects here are awarded to the lowest bidder because of the government. However, in much of Europe and Japan, they are awarded to bidders who provides best warranty. More care taken to complete work and much less work needed to make changes because you can reuse existing base. May cost more to build initially in Europe, but much lower costs in future. Low bidder here figures they will make it up on changes. In US, we don’t care because we will just replace it… Lower bidder has to make profit so they hire lower skilled and less productive.\n\n \n\nThere is a culture growing in construction trades to care less about others work. Trade A (electrician) doesn’t care about another Trade B(plumber)'s work. If Trade B does something that is in way of Trade A, they just cut through it and then don’t tell anyone. Eventually Trade A has to come back and fix. And at end of day, they don’t finish what they are doing, they just leave. Then next day they have to inevitably rework some portion of work they did yesterday.\n\n \n\nAnd I think our geography may play a role. Workers have to travel further because we are much more spread out. Makes for unhappy workers which equals unproductive workers."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How does a gas stove prevent the flame from going in?
|
[
" Combustion requires three ingredients: fuel, oxidizer, and heat. Only when all three are present can a flame occur. This happens at a stovetop burner where gas from a pressurized pipeline mixes with oxygen from the air in the room, with a spark to ignite it. Inside the pipeline, however, there's only gas. You can heat it all you want but it won't burn if there's no oxygen to react with.",
" Flame needs oxygen and fuel to work. The fuel is the gas, the oxygen is in the air. Inside the cylinder there is no oxygen, only fuel. In the air there is no fuel, only oxygen. This means flame can only burn where fuel meets air: the top of a lighter (butane meets air); the surface of a log (the wood being the fuel); and indeed the top of your gas stove.\n\nThe exception is when fuel and oxygen are premixed inside the container, then a lot of fire is produced very quickly inside the container this is how most bombs work. Your gas cylinder is especially designed NOT to explode, so has no oxygen inside it."
] |
[
" there is no special mechanism there is just no oxygen in the tank for the fire to breath. fire needs fuel (like wood or in this case propane) oxygen (to breath) and an ignition source (which would be a lighter on the gas stove) without oxygen it has fuel and an ignition but can go where there isnt oxygen so stays where there is.",
" Put a block of stone on your stove.\n\nI mean, don't, but pretend you did.\n\nEven if it doesn't burst into flames, the heat still warps and weakens the stone."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why is the reflection of the jar on the cellphone not blurry?
|
[
" Keep in mind the reflection is light traveling from the jar, to the phone, to the camera; this is different than if the phone had a *photo* if it was a photo then the light would only be going from the phone to the camera."
] |
[
" The same reason you see your reflection in anything other smooth surfaces eg mirrors/polished metal. Perfectly smooth surface means that light bounces off it at exactly the same angle at which it hits it. \n\nReflections are fainter in glass because most of the light passes through it, only a small amount gets reflected.",
" Basically because the mirror *reflects* the light with all of its properties still intact. When light reflects off an object, that object interferes with the light. It gives it new properties that your eyes use to determine its color, depth, etc. A mirror just redirects the light with the same properties it had."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
what would happen if i stood on a train going at the speed of light, and took a step forward? Would i go faster than light, or would it be physically impossible?
|
[
" If a train was going at the speed of light, you wouldn't be able to take a step forward because time would stand still.\n\nIf the train was going slightly below C and you started running so that the combined train & running speed was above C, it would work - an outside observer would however see you running in slow-motion (because time would run slower for you), so that your running speed+train speed would still be below the speed of light.",
" You can't actually travel at the speed of light, so for this question, let's assume your train is going 1m/s slower than light.\n\nAt that speed, time would be stretched by a factor of about 300,000,000.\n\nThen you start walking/running at 2 m/s, which seems like it should take you faster than light. But due to the stretching of time, you're only moving about 7 nanometers per second faster than the train. (2 m/300,000,000 s)\n\nSo nothing would be different."
] |
[
" Imagine you're standing in a spherical train car on a track. You're not strapped in, you're just standing in it.\n\nWhat happens if the train were to suddenly take off at 100 km/h, and then stop after a second?\n\nYou'd fly into the side of the sphere opposite of where the motion is and then fly into the other side when it stopped.\n\nThis is what happens to the brain. it bounces around inside the skull when it is hit hard enough.",
" No, because it turns out that that isn't how the universe works.\n\nIt *appears* to do so, because we're used to really, really slow speeds. If you're in a train travelling at 100 km/h and you walk towards the front end at 2 km/h, you expect to be able to add the speeds and say that you are moving at 102 km/h (relative to the tracks, that is).\n\nBut in fact, that's not quite true, because the universe isn't constructed quite as simply as that. You're actually moving at *very slightly under* 102 km/h. The difference is so tiny, you can't measure it; but it's there.\n\nThe faster you go, the more pronounced this effect becomes. And once you reach the speed of light, this effect is so huge that you can't actually go any faster. No matter how much you try to accelerate, you can't: the speed of light is the fastest speed possible in this universe.\n\nThis is a bit mind-blowing, but here's a thought experiment for you: If you and I stand back to back and then start walking away from each other, at a constant speed and in the same direction, what's the furthest we can get from each other?\n\nYou might say that, at least in theory, we could continue getting further away from each other for all of eternity, but you'd be wrong. In fact, the furthest distance we can get from each other is 20,000 kilometres. Once we've reached that distance apart from each other, we can continue walking in the same direction at the same speed, but the distance between us starts to *decrease*.\n\nWhy? Because, contrary to appearances, the earth is not flat. And although it has no edge, it has a size, and that size means that 20,000 km is the greatest distance possible between two people or objects. There is no such distance as, for example, 25,000 km -- it doesn't exist on our earth.\n\nIn a very similar way, the fastest speed any two objects can move relative to each other is the speed of light. There's no force stopping you getting past that, in just the same way that there's no invisible wall stopping us from walking more than 20,000 km. It's simply the way the universe is constructed: it's a fundamental property, as fundamental as its size, that c is the fastest speed, and no speed faster than that exists."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How does anonymous hack into websites and how are they structured if they are all completely anonymous?
|
[
" 'Anonymous' isn't really a single group, it's a generic identity for 'hacktivists'. Anybody can claim to belong, and people that don't claim to belong might get lumped in with them anyway.\n\nHow one can crack into any website or network is a lot like asking how someone can break into a building: there's a huge collection of ways, and not all of them would work on all targets. Indeed often it's more varied in the computer security world because very often it takes a string of security breaches before the hacker gets what they're looking for. \n\nThe generic answer is they exploit security flaws they find. There exist companies and freelancers that do 'whitehat' hacking on contract and tell you about the flaws they find without exploiting them as a service, but many, many companies are pretty lax about their security and never bother with security audits or the like."
] |
[
" Via many methods, which due to the rapidly progressing nature of technology may change constantly.\n\nThe easiest and cheapest is just to use someone else's internet connection. Use a public access spot, hijack a random person's wifi, or use that of a government building, etc.\n\nYou can somewhat anonymize yourself by routing your connection through one or more proxy servers. Traffic coming from the proxy looks as if it is coming only from that proxy, probably mixed with traffic from dozens or hundreds of other users. Said proxy server is probably located in a different country that may or may not cooperate with law enforcement from the country where the crime is committed, and whose owners probably intentionally don't keep records of inbound connections.\n\nBeing a cybercriminal in a third world country that does not care or does not have the resources to investigate such crime helps, too. Bonus points for targeting foreign countries for your exploits which your home country won't cooperate with, is enemies with, or won't extradite anyone to.\n\nThere are many other techniques such as onion routing (Tor and similar), encrypting all of your activities, using disposable computers/cell phones, spoofing your MAC address and originating IP address, etc. And combinations of all of the above. Not all of them are effective -- cybercriminals get caught all the time.",
" I will cover Anonymous first. Most of the work they do is actually not hacking/cracking but something called [DDOS](_URL_5_). Through DDOS they are actually not trying to break into a service but actually just trying to bring down the service (eg. Paypal/MPAA etc) for few minutes which is nothing more than a little bit annoying at max. \n\n However Anonymous have actually done fair bit of hacking. The best case I can think of is HBGary. I think there are some great reports done by Engadget or Gizmodo on the subject. I will try to find out more details on same . \n \nNow in general about hacking. I believe we can break this further down to two categories. \n\n* Defacing Websites\n* Intruding into secure Networks\n\nDefacing websites is not really that difficult. With some knowledge of [XSS](_URL_0_), [SQL Injections](_URL_1_), [XSRF](_URL_2_) ( all application vulnerabilities) or even attacking the serving OS for known vulnerabilities, if any one can get root access on any web server then he/she can possibly change the whole websites overnight. These are the type of attacks, when you hear that someone hacked the websites of CIA or MPAA and left some messages on front page. It just means that someone was either able to get access on the main server or used used one of the exploits (XSS etc) to change content on the websites. \n\nNow we come to intrusion of secure networks. This is little more complicated. These are typically the cases when you hear that confidential mails or other sensitive matter was stolen (eg. HBGary,Google in China). The primary attack method is something called \"Social Engineering\". Its normally targeted at the weakest link in the whole security arrangement, the people running it. This is how it unfolds generally . \n\n* Lets say that you are a person working for a corporation X at some mid level position. One day you get a message/mail from one of your friends accounts(which is hacked ) with message in tunes of \"Check out my Pics\". You would generally click on it and would be taken to a login page( like Facebook/Google/Yahoo). What you may not realize is that this is a fake page being hosted out of Russia or China. You then casually provide your real username and password and are redirected to your facebook page. This process is called [\"Phishing\"](_URL_4_). \n\n* Now technically your outside account is compromised, but how does that matter to the corporation. Well most people for convenience use the same password for everything(dangerous practice). So there are good chances that as a Hacker, if I managed to phish 10 employees, then atleast one of them would be using the same password for corporate/official account too. \n\n* So well, now your corporate account is hacked. Now all depends on how senior your position is within the company. As a hacker I would send out mails/messages to various other people within your organization to request further sensitive information or access. \n\n* After this as a Hacker my only limitation is really my own creativity. I can steal mails, source code and all kinds of sensitive data. \n\nThis is just an example that I gave you to show how such an attack could be carried out. Actual attacks may differ or vary in some way and form depending on the situation. \n\n**Disclaimer** : I am an Engineer working for one of the web giants. I also volunteer to increase the security relating to the products that my group owns. Also apologies for long post and for atrocities done on English language, its not my native language.\n\n**Edit**: The HBGary story was done by Arstechnica [Link here](_URL_3_) . Do read it, its quite detailed and explains the process really well."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How were years originally created and how did they know which year it was?
|
[
" The original \"year\" was determined by the position of celestial bodies (sun, moon, and mostly stars) and to a lesser extent weather trends. Early scholars noticed the \"movement\" of the starts, and the angle of the sun, phases of the moon, when it got hold/cold/wet/etc, tied them all together, and noticed the pattern(s) and when they repeated. From that they came up with a pretty good idea how long a month and a year were\n\nYear numbering has varied among cultures based on what they used as a zero point. Our current calendar has even been adjusted/reset a few times to adjust for cultural/political changes"
] |
[
" The idea of counting years since the birth of christ didn't show up until around the 6th century, and it didn't change the days and months of the existing julian calendar, which had been in use for nearly 600 years at that point.",
" The AD system was invented in about 525 AD, and came into common use a couple hundred years later. Before that, people in the West didn't usually number years; they just said \"the Xth year that King Y has ruled\"."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What is a democrat and what is a republican, and how are they different from a liberal and a conservative?
|
[
" Conservative and Liberal terms are *ideologies* (think of it as a philosophy or lifestyle they relate to), while Republican and Democrat terms are *identities*. You register as a Republican or Democrat on a national level, but the ideology you follow can vary depending on what your views are. \n\nThe reason why they correlate is because **generally** Liberals identify themselves as Democrats, while Conservatives identify themselves as Republicans since those are the parties they believe represent their views the closest.",
" A democrat/republican is a person that belongs to one of the national political parties. The parties are local affiliations that are organized at the state level. Parties vary from state to state, what might be considered conservative in Mass would likely be liberal in GA or Tenn.\n\nFor any given fixed area Democrats tend to be more liberal than the Republicans, but it does no good to compare across state lines, especially when considering different regions like NE, West, Mid-west, South-west, and South-east."
] |
[
" Short answer: [stormy_sky says it well](_URL_0_).\n\nLong answer: It's complex. At the national level, despite what cynics say, there is a clear ideological difference between the parties - if you order congressmen on a single liberal/conservative axis based on their votes on the floor of Congress, there's literally no overlap between the two parties. The country as a whole is more moderate than Europe, though, so relatively speaking, you'd probably see Democrats as stretching from center-left on the liberal fringes (people like Senator Bernie Sanders, who identifies as a \"Democratic Socialist\") to center-right on the more conservative side, and Republicans as pretty much far-right.\n\nThings get muddied, though, because these two parties also are (for the vast majority of cases) the only two major parties at the state and local levels, despite average state ideologies running across a pretty wide range. So, a Southern Democrat might end up being more conservative than a Northeastern Republican, just for survival's sake. Hence why Mitt Romney was a generally moderate Republican when he was Governor of Massachusetts (a very liberal state), but a pretty conservative one now that he's running on the national stage.\n\nBasically, both parties are big tents. Third parties don't generally have a shot, so instead of a system of many parties running and forming coalitions after the election, like in some European countries, we have those factions join together pre-election, and suck up some compromises amongst themselves in order to get elected. Asking \"what do Democrats stand for?\" will get you very vague answers, because there's only a few clear issues where everyone agrees. In 2010, some Southern Democrats ran ads bragging about how they \"stood up to President Obama\", even. And parties have much less control over their members than in most European countries, so it can be difficult for party leaders to \"force\" any positions - the leaders don't choose who gets on the ballot, we do that through primaries.",
" Republicans are usually fiscally (money-wise) and socially conservative.\nYou can have a fiscally conservative but socially liberal republican. (anti tax raises, pro gay rights)\n\nDemocrats are usually the opposite. However they can at times be socially conservative.\n\ngenerally whether a person is an R or a D depends on their fiscal stance however in recent times that has been getting warped to them being more socially centered roles; which is not how it was originally intended"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does warm milk and honey make people drowsy?
|
[
" Milk contains carbohydrates, proteins, and fats all of which make one feel full and help the brain absorb tryptophan from the milk. Tryptophan contributes to the initial feelings of drowsiness, but not the overall amount or quality of sleep one gets. Drinking warm milk can slightly increase the body temperature which is also character of the body preparing for rest.\n\nI cannot attest to the effects of honey on drowsiness but milk has some backing and sort of makes sense if you consider what it is that you are drinking. It is the primary source of nourishment for a mammals in their infant stage where more sleep is required so the fact that it makes people feel a bit drowsy isn't too surprising to me.",
" Honey contains a lot of sugar (fructose and glucose), as does milk (lactose). The combination of the two causes a spike in blood sugar levels and increases drowsiness. \n\nEdit: As u/rumbidzai clarified in the comments below, the rise in blood sugar doesn't directly cause drowsiness. Rather, it's the insulin the body releases to metabolize the sugar that causes drowsiness a short while later."
] |
[
" Milk has a sleep inducing amino acid called tryptophan, this causes babies to go to sleep. Even grown ups actually.",
" I had a kines teacher who said that it is a result of your heart rate slowing too rapidly. Your body basically thinks your dying, and jerks you (tehe) thereby increasing your heart rate.\n\nThis explanation would coincide with rivensteel's explanation. Caffiene/ stress before sleeping would cause a high HR"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How do bowl games work in college football?
|
[
" Bowl used to simply be an exposition, usually the winner of a particular and a strong out of conference team, and had no real bearing on who was the champion. In fact, the NCAA didn't (and still doesn't for Division I) have an official national champion. Winning a bowl game did give you some bragging rights if you wanted to claim you were the best, but that is all it would be, just a claim.\n\nLater, they started manipulating the bowl invitations to make it more likely the best teams would face each other and instituted polls so there was a semi-official #1 team, but both were controversial and often muddled by politics. Recently, they restructured the bowls so there is now four-team playoff that rotates through the most prestigious bowls, but that remains controversial as a lot of good teams are still excluded. The remainder of the bowl games remains expositions.",
" Back in the old days, college football teams would just play whoever they wanted to, it was pretty disorganized. Even after conferences formed there were a lot of teams that didn't join a conference and just scheduled games against other teams for whatever reason.\n\nBut for the teams that were in conferences, there grew up a lot of rivalry around whose conferences were better, and which teams were better. Since the football teams only played once a week or so (unlike basketball where a team might play 2-3 times a week or more) it was hard to schedule big tournaments like they have in other sports. The result was so-called Bowl Games which were big end-of-season games, often set up between the best teams in certain conferences. For example, the Rose Bowl for a long time was always the best team from the PAC-10 versus the best team from the Big Ten.\n\nThese Bowl Games over time became very prestigious, and the main goal of a college team's season might be to try to get into one of them. But with so many teams and so few prestigious bowl games most teams were left out. To help deal with this demand, other less prestigious Bowl Games started being played. These lesser Bowls would invite teams that were pretty good but not exactly the best. And eventually even teams with mediocre results could get invited to a Bowl Game, albeit a very low status Bowl that hardly anybody cared about.\n\nWhile all this was going on, there was also a lot of talk about which one team was the best. Because there was no end-of-season tournament, just a bunch of Bowl Games, it wasn't always clear who the best team was. Various polls would be taken during the season, but the results could be controversial. What if two (or more) teams ended the reason undefeated? Who is really the best team?\n\nTo settle these disputes, back in the late 90s the big conferences put together something called the Bowl Championship Series (BCS). Instead of the old invitation-based system they agreed that the top few teams would always get to played in the best Bowls, and that the #1 and #2 teams would play in a special game called the BCS Championship.\n\nBut as you can imagine, this didn't really settle things either. Teams and fans still argued about who was deserving of being in the BCS Championship. Over the years there has been a lot of people who wanted a tournament like other sports have, but the people in control of the Bowl Games like the system the way it is -- there is a lot of money and prestige involved and they don't want to give that up.\n\nSo after a number of years they made a compromise in which the top 4 teams have a \"mini-tournament\" called the College Football Playoff. That has been going on for 4-5 years now but to no-one's surprise there is still a lot of disagreement about which teams should be in the top 4. Maybe someday the College Football Playoff will expand to 8 teams or more but not in the near future.\n\nSo what we have today is a kind of hybrid system: some teams get invited to bowl games, and some teams are in the mini-tournament playoff. To make matters a little more confusing, the individual games of the mini-tournament are also considered Bowl Games with names like the Sugar Bowl, Fiesta Bowl, Peach Bowl, etc. These individual Bowls have to take turns being part of the mini-tournament, some years they are a de facto National Semifinal game and other years they are just regular Bowl Games.\n\nThat leads us to the situation we have today. The college football season runs from early September through early December, which most teams playing every weekend (taking off a week or two in that time period). Then the teams who qualify get invited to Bowls. The Bowl Games begin in mid-December, starting with the least prestigious contests in which the less worthy teams participate. As the month goes on the games get gradually more and more noteworthy and the teams get better and better. This is not a hard rule -- sometimes a team is that more popular will get a better bowl even though it didn't have such a great season. It's all about viewership and making money."
] |
[
" For the same reasons we haven't gotten rid of the bowl game system for determining the national college football championship. Both were developed in a time when a truly inclusive national competition was both unworkable and unthinkable. For both, having a set of independent competitions, all at the same time in different places, worked. Over time, local interests got so much power vested in the way the system works that no one wants to shake up the system, and you'd have to get cooperation from so many stakeholders who would stand to lose power that you'd never make it happen. Finally, there are arguments that the results would not necessarily be any better, and the net gain might not be worth all the investment in making the change.",
" There is nothing like a scrum. Whereas rugby is a continuous series of plays, American football happens one play at a time. The plays are carefully choreographed, happen quickly, and there is a lot of time between plays. A three hour game will have about 11 minutes of actual action (the game clock can run between plays so a 60 minute game will never have 60 minutes of play).\n\nTo an extent, American football is strategic, like watching a chess match. The blend of strategy and violence allows for \"war\" comparisons. Fans argue and complain about what play to run at what time. You aren't watching for the purpose of non-stop action. In fact, players are specialists at either playing offense or defense, or kicking, and stick to their specialty - they sit out when their team does (or does not) possess the ball.\n\nThe play always begins with the offense and defense at the \"line of scrimmage\" - the place where the offense controls the ball. The object is to move that line of scrimmage -- and therefore the ball -- into the end zone (like rugby). But two things stop the play and allow both parties to regroup: 1. if a player is tackled in-bounds with the ball, or 2. If a forward pass is thrown that hits the ground. The offense is allowed one forward pass per play, and it must occur before anyone controlling the ball has crossed the line of scrimmage. So you can't run some, and then throw. Your play has to be to throw at the start of the play. This lets the defense anticipate either a run play, or a pass play.\n\nWhen your team's line of scrimmage is established, you have 4 plays to move the ball 10 yards. If the ball is thrown and hits the ground, you have lost one of your 4 plays, and the ball returns to the old line of scrimmage. Plays are called \"downs\". So the first play is \"1st down and 10 to go\", or \"1st and 10\". A pass that hits the ground (an \"incomplete\" pass) would make it 2nd and 10 for the offense.\n\nIf you are on your own side of the field and fail to earn your ten yards (\"convert a first down\") after 4 downs, the other team takes the ball at your line of scrimmage. This is considered terrible, so on 4th down, teams may choose to kick to the other team (\"punt\"). It forfeits the ball but moves the line of scrimmage to the other side of the field (provided they can tackle the player on that side of the field - almost always true).\n\nIn the NFL, teams play so safe that they almost always punt on 4th down. It's practically a controversy if they ever fail on 4th down, so they play not to lose rather than to win. In college or high school, you may see teams take risks.\n\nPossessing the ball means converting 1st downs, usually several times, and moving your line of scrimmage gradually downfield. (You could have a big play and score instantly but that is rare - a very good, less common play typically gains 15 to 20 yards instead of 80 or 90).\n\nIf it is 4th down and you are close enough to kick through the goalposts (10 feet off the ground and 10 yards BEHIND the end zone), you can score 3 points. This is a \"field goal\". The kicker is brought on to the field only for this reason and does not play in other situations. The ball is held with one finger on the ground, not drop kicked. The drop kick is legal in this situation but never used. Punts are drop kicked.\n\nMoving the ball into your opponent's end zone is a touchdown and results in 6 points, with a chance at an \"extra point\" kick (made 99%+ of the time) or a 2-point conversion (one down from 3 yards away - only used when needed, about 50% success rate). \n\nWhen a ball that has been clearly possessed by a player (either clearly caught and not bobbled, or ran with) is dropped, it is a fumble, and any player can take it. Players usually dive to fall on the ball and make it clear that they are taking ownership of it; this is smarter than trying to pick it up on the run. This is the closest you will come to a rugby scrum. \n\nI've only scratched the surface, but hope this helps. American football is a great sport. Like baseball, it is not a sport where players run non-stop to the point of exhaustion, but rather it is managed by coaches and the players are like human chess pieces. It differs greatly from hockey, soccer, and basketball in this regard."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why can't / don't political candidates sue each other for defamation of character when they run negative campaign ads?
|
[
" Many don't lie, slander is a civil tort not a crime. To sue is the only way to resolve it and does not look good during a campaign usually. \n\nOccasionally some ads do lie and are removed but defamation needs to show malice. Not stating something in a certain way, but actual malice. Often time it's just telling something in a certain way with just one side of the story. It's factually true, but doesn't tell the whole story obviously.",
" As I understand it, there is no federal truth-in-advertising law that is specifically written about political ads. Also, the Supreme Court ruled in the Times v. Sullivan case in 1964 that a public official can't collect damages for a defamatory statement unless they can prove that the statement was made with knowledge that it was false or that the person made the statement with reckless disregard of the veracity of their claims (Very difficult to prove). Lastly, not all political ads are created or endorsed directly by the candidate, so any private lawsuit against them wouldn't hold water in court. Not to mention the amount of time that would be spent in court might be longer than the election cycle.\n\ntldr: There is no point because they can't collect for damages/won't fix the damage in time for the election"
] |
[
" They do, but the standards are different for public figures. Proving defamation against a public figure requires a showing of malicious intent, not just mere negligence (the standard applied to statements/writings about ordinary citizens). That is a simplified explanation, but basically sums it up. The reason is derived from the First Amendment, and the importance of having an unimpeded public discourse about public figures and matters of public interest.",
" Well, both are protected by the First Amendment, just to varying degrees, and both only until they do--or rather, say--something that makes them *un*protected speech. \n\nPolitical speech, historically, has been given a very, very wide berth of protection by the First. The reason? A free society needs to be able to be critical of the government, those currently *in* it, and those *wanting* to be in it.\n\nHowever, patently false, injurious claims can be slanderous and libelous, and are decidedly *not* free speech. So, how do the two coexist? \n\nActual malice. \n\nThe Supreme Court ruled, in the landmark *New York Times Co. v. Sullivan* that speech becomes its unprotected forms of slander or libel when the *public figure* about whom false claims are made can prove the claims were made with *actual malice*. \"Malice\" in this context doesn't mean \"I wish to hurt you\", instead it has to do with whether the publisher of the claims either knew the claims to be false, or acted with reckless disregard for the truth. If either of those can be proven, the published claims (in this case of a political nature) are *not* protected by the First, and damages can be awarded or other penalties enacted. \n\nSo, for those \"untruthful\" political ads, the bar is set rather high for whether the statements they make cross into \"unprotected\" territory, as the need to be able to openly discuss and criticize political goings on is essential to liberty, and thus more important than the reputation of those in government, up to a point.\n\nCommercial speech (advertising) is similar: it is \"protected\" by the First so long as it doesn't cross an abstract boundary, though in this case the Supreme Court decided that the bar should be much lower.\n\nIn *Central Hudson Gas & Electric Corp. v. Public Service Commission*, the Supreme Court decided that \"commercial speech\" isn't protected by the First (i.e. governmental regulation of the speech isn't unconstitutional) when it fails what is now referred to as the *Hudson Test*, the first \"prong\" of which reads: \n\n > At the outset, we must determine whether the expression is protected by the First Amendment. For commercial speech to come within that provision, it at least must concern lawful activity and not be misleading.\n\nSo, if an advertisement is \"misleading\", it is not protected by the First, and is opened up to regulation at the Federal or State level. This boundary is quite a bit more abstract than the *Sullivan* actual malice standard for defamation of a public figure."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Is milk healthy for me? I'm an adult, but I haven't drank milk for years.
|
[
" Women who drink milk are more likely to be diagnosed with osteoporosis than those who do not. \nThe milk company is responsible for the hype that it is healthy for you. \nAfter weaning, just as other mammals, we have no need for milk. \nThere are many other alternatives to getting calcium. Soy milk has more calcium in it than regular milk.\n_URL_1_",
" It isn't really known. Throughout the 20th century, it was widely believed that milk was healthy and good, but recent studies seem to contradict that fact. More trials are needed go give a definitive answer."
] |
[
" Humans started drinking cow's milk in Northern Europe thousands of years ago where long, cold winters meant months with no fruits, vegetables, and meats.\n\nWhen your diet otherwise consists of just grains, milk and other dairy products like yogurt and cheese provide an excellent source of protein and many vitamins.\n\nIf you eat a good balanced diet, there's no reason to drink cow's milk today. There are plenty of ways to get all of the nutrition you need from other sources.\n\nHowever, from a purely nutritional point of view, there's nothing *wrong* with drinking cow's milk either, unless you're extremely lactose intolerant.",
" Milk had nutrients just like any other food. But is it essential? Not really. You can get those same nutrients from a bunch of other foods.\n\nThere is a lot of things we need to learn about nutrition. You could go to several different \"professionals\" on the subject, and they would all give you different advice. I guarantee if you quit milk for a year, you would survive."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
what the brick on a power cord is / does.
|
[
" There are a few reasons.\n\nSome devices need less power than the wall provides, but they will pull all the power they possibly can, even if it burns them out. So you need a device between them to reduce the power.\n\nSome convert from AC to DC.\n\nThe power sent to your house comes in AC. Imagine a pipe of water blocked off at both ends. The water is pushed back and forth. This is AC (Alternating current) The brick turns it into DC (Direct Current). Imagine your electronics as a loop of water pipe. The energy from the AC is used to pump the DC loop of your computer or device.\n\nI could get into why some devices can use AC and why some need DC, but that's a different ELIF.\n\nEDIT: Spelling"
] |
[
" Long story cut short: You could, but we don't because it isn't safe or it is too expensive to wire for 100 devices on one circuit at once. Extension cords and power bars aren't really any different from the wiring and outlets hidden in the walls except that they are portable. Long explanation follows:\n\nIf you have a hot wire (a charged wire) and a second ground or return wire, you can run anything that will work on the line voltage as long as the wiring can provide the amount of current being demanded. Really, an extension cord is basically the same idea as a wall socket, except instead of the wires being hidden in the wall, they are right there to see. In fact, the wiring in a house is basically an extension cord from the street lines. The same basic idea.\n\nWires have a maximum current load (generally 15 or 20 amps for household wiring but you can get higher capacity wire if you are willing to pay for it or if it is necessary) that they can safely handle before they start to overheat and perhaps catch on fire or cause fire to start nearby. For this reason, the electricity in a building is divided into sectors, usually one or two rooms for each sector, and each sector has its own fuse or circuit breaker (so the entire house does not lose power simply because of a fault in one room). the current load that the breaker can handle must not exceed the safety rating of any downstream wiring or you risk a fire when the cheaper wire that is getting too much current overheats. The breakers are sized to shut off power to the sector when the current gets near that maximum safe draw for which they are designed (never put a coin in place of a fuse, for example; the coin won't melt until you demand way above safe current needs for the wiring, good chance to burn down your house).\n\nWhen you use an extension cord, you are basically plugging many devices into one single wall socket, so you can fairly easily equal the current demand for the sector via a single outlet. In effect, instead of plugging each device into a separate wall socket, you plug them into sockets on the power bar and that connects to a wall socket. As long as the wall sockets are on the same circuit, it really isn't any difference whether you use a single power bar or several separate wall outlets, except for convenience.\n\nYou won't be able to power 100 things all at once because the fuse or breaker will prevent you. If you have five devices on a power bar, and try to run a microwave oven (or similar high current device) on the same circuit (an outlet on the same breaker or fuse sector), you will probably demand more current that can be supplied safely, so the fuse or breaker will cut power. Many people find that running a toaster and a microwave oven will trip the breaker for the kitchen, because each device draws a high current of maybe 10 amps or more.\n\nThe issue is not whether the street supply can run 100 devices (it can and does serve many houses on the same supply so easily supplies 100 devices in total), it is a question of how you have wired from that street supply and what each wire in your house can handle for current. \n\nIt is a safety issue more than anything. Big wires (like for the street supply) carry a lot of current without overheating. Smaller wires cannot safely take as much. We wire the house according to typical needs and with costs in mind. No house is designed to run 100 devices on a single circuit. It is not that it cannot be done, just that it is not actually very safe, or if it were safe, it would be very expensive.\n\nSorry, this isn't very \"for a five year old\" explanation.",
" Imagine you're dropping bricks off a roof, because you want to smash something down below. \n\nVolts = the height of the roof. More volts = higher roof.\n\nAmps = how fast you are dropping the bricks.\n\nWatts = how much damage you're doing on the ground. \n\nOhms are a little hard to fit into this analogy... I guess a good one would be the viscousness of the material the bricks are falling through. A normal wire would be air. Increasing the resistance would be like making the bricks fall through water (medium resistance), or jelly (high resistance). Things falling through a vacuum = superconducting :)"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How does investing work
|
[
" Investing is sort of like buying and selling, except the value is not determined by the seller. Sales is buying a book at $1 and selling it for $10 - you set the price. Investing is buying a book at $1, and suddenly all other copies of that book disappears, the author decides to stop writing, and now everyone wants to buy that book for $10 - you did not set the price. \n\nOf course, it could go the other way. Perhaps someone else wrote a similar but better book, and it is now worthless."
] |
[
" It has to do with the logic of investing.\n\nWhen you invest in a company, you are gambling that they are gonna turn a profit and pay you back more then you invested.\n\nKeyword: Gambling.\n\nThere is ZERO guarentee that you are not throwing your money away. Have you been following MoviePass? Some people paid $20/share for stock. You can pick it up for about 2 cents a share today. Legally those people have very, very little ground to stand on. They are simply out that money. When MP declares bankruptcy it becomes even more difficult.\n\nWhen a company goes public typically that is the last tier of people given the opportunity to invest. So, as a joe schmoe investing seems like a smarter idea if there are already a bunch of people firmly committed with the company.",
" The term \"investment\" is very, very broad. In general terms, investment is taking your money and putting it to some use that increases your wealth. In most cases, investment generally means buying *something* (be it stocks or bonds or mutual funds or businesses or real estate or commodities or whatever) that will appreciate in value over time, so that you can later sell the thing and extract the value, or earn money from the income that thing produces.\n\nThe most common investment tools for average Joes are probably stocks and bonds (which are usually acquired through a diversified pool of stocks and/or bonds called a \"mutual fund\") as well as real estate (which often appreciates over time, and which can generate revenue from leasing).\n\nIn your situation, I would impress upon you the importance of paying off debt. Don't get me wrong; investing your idle money is very, very, very important. But paying off your debt is even moreso. The longer you owe money, the faster the interest payments on the debt will eat into your assets and income. So the faster you pay it off, the better off you are.\n\nPaying off debt is perhaps even more important now than usual because interest rates are low (which adversely affects returns on a lot of investments) and the equities (stock) markets are still pretty damn volatile. Given these factors, it's entirely possible that the the interest rate on your debt would outpace whatever return you got on your investment.\n\nSo my advice would be to put whatever money you can part ways with toward your student loans. It's not a sexy answer, I know, but I think it may be the most practical."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why is wearing a hat disrespectful?
|
[
" Removing your hat has been a gesture of respect in Western society for a while. So as a side effect of that, failing to remove your hat is disrespectful."
] |
[
" It's a leftover from when taking hats off was a mark or respect and good manners. You might have heard it's rude to wear a hat indoors, it's the same concept. Similarly, you'll often see in films people standing up and taking hats off and holding them to their chest as a marks of respect. \n\nNot too sure where the custom originated. I suspect it came from Roman/Classical times to take the war helm off to indicate there was no danger. Taking ones hat off would show that you trust the person, keeping it on would imply you thought them a threat.",
" From _URL_0_:\n\n“Taking the hat off is the modern remains of the ancient custom of\nKnights who removed their helmets in the presence of those they felt\ntheir friends and thus, before those they wished to honor by showing\nthat they trusted them. A man removes his hat before a woman to show\nhis respect. Touching the brim is but a perfunctory salute.”"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does water expand when frozen (ice), as opposed to other substances?
|
[
" When frozen, water molecules arrange themselves in a particular grid-like pattern with lots of empty space between each molecule, thus increasing its volume."
] |
[
" The water warms the surface of the ice which causes it to expand and crack from the expansion.",
" Solids expand when they get warmer.\n\nWhen you put the ice cube in water, the outside warms and expands faster than they inside. Being brittle, something has to give, and the result is often cracking."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
When watching TV with subtitles, explain why our minds always (seemingly) choose to read text rather than just watch and hear audio?
|
[
" It's because our brains don't choose. Reading isn't something you have a choice to do or not.\n\nThings that we learn to do are largely unconscious and out of our direct control. Like, we can't choose how to run, our brains just move our legs in the way they've learned to. And once you've learned to read you can't help but understand words when you see them. Learning literally rewires your brain so it just it whenever it sees the right kind of patterns.\n\nSo to not read subtitles you have to actively try and keep from looking at the part of the screen with the words on it. Which is actually harder than it sounds because [our eyes are jumping around all the time and we don't realize it](_URL_1_). So you have to actively fight two natural habits to avoid reading, which is a lot of work, especially to do it constantly through an entire show or movie.",
" I'm confused. When watching things subtitled, I've never 'read the text' like a book where you read line by line. You watch the film, and the text is just another part of the image the brain processes. If you focused directly on the text you'd be missing too much content."
] |
[
" In my experience, kind of. But it's a learned skill. When the average person is watching a movie or TV show, their brain is purely focused on the visual. When people first start watching something with subtitles, they'll focus on the subtitles because their brain isn't trained to read and watch something simultaneously. Eventually you learn to split your attention, but you still have to focus on them to some degree. But you don't have to focus solely on the subtitles.\n\nAn interesting way around this is in The Shape of Water. In scenes where sign language is subtitled, the subtitles follow the focus of the scene, so as you're following what's happening onscreen you're automatically focusing on the subtitles.",
" for me personally i use subtitles as im a fast reader and follow the plot better that way, although it can spoil some moments."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What are NASDAQ and Dowjones
|
[
" A stock is the money a business gets from giving out shares. (Simply and literally: shares in the company by %)\n\nA stock exchange or share market is a place where people meet to buy and sell shares of company stock. Some stock exchanges are real places (like the New York Stock Exchange), others are virtual places (like the NASDAQ).\n\n**NASDAQ** is a virtual stock exchange. It stands for **N**ational **A**ssociation of **S**ecurities **D**ealers **A**utomated **Q**uotations. About 3,800 companies trade on it.\n\n\nThe Dow Jones Industrial Average, also called the DJIA, Dow 30, or informally The Dow Jones or The Dow or Dowjones (as you put it)) is one of a few stock market graphs used to look at how well a market is doing created by a Wall Street Journal editor and Dow Jones & Company co-founder Charles Dow. There are 30 companies that make up the Industrial Average. It used to be that most of the companies were in heavy industries, such as steel, oil, cars, and appliances, but it now has from many different industries.\n\nIf you want to buy shares in the big companies that are in the Dow, you trade on the Dowjones. If you want to buy shares in companies that are on the NASDAQ (Microsoft, Amazon etc), you trade on the NASDAQ. \n\nThe NASDAQ is also used as an index as its an electronic marketplace. \n\n\n**TL;DR: They are markets where business people can trade % shares in businesses.** \n\n[This is a good read if you have a little time. Its quite readable.](_URL_0_)",
" NASDAQ is a market where stocks are sold. A stock is essentially a share of a company: if you own a stock in, say, Apple, it means you own a part of Apple, and are entitled to a percentage of their profits, depending on the percentage of total stock that you own.\n\nStocks are sold on different markets around the world. There are many big ones in major financial cities, such as London, New York, Tokyo, Hong Kong, etc. The NASDAQ Market is the second largest in the world behind the New York Stock Exchange (NYSE).\n\nThe Dow Jones Industrial Average (often abbreviated to just 'the DOW') is an index measuring the value of the 30 largest publicly traded companies in the United States. (To be publicly traded means that you have issued stock, and those stocks are traded on markets such as the NASDAQ, NYSE, etc)."
] |
[
" There are a variety of stock market *indices,* and the Dow Jones Industrial Average is one of the best known. It's a number, essentially, that represents the average share price of thirty large, publicly traded companies.\n\nIn essence, at any given time they take the share prices of those thirty companies, add them together, and divide by … well, a number. If it were just a simple average, that number would be thirty — that's how you compute a simple average: sum up all the components then divide by the number of components. But the DJIA tweaks that a little bit to cancel out the effects of things like stock splits. A stock split changes the share price of a stock issue, but does not reflect a change in the value of the stock issue. It's like saying \"I'll give you two fives for a ten.\" The face value of your bills changes, but the total amount of money in your wallet stays the same. The DIJA is calculated in a way that such events have no effect on the index. So it's not a simple average, but it works like one.\n\nBasically, when the DJIA goes up, it's a sign that the thirty stocks that make up the average are trading higher overall. Because the stocks chosen to be a part of the index are middle-of-the-pack representatives, this also generally indicates that the entire market of publicly traded companies is trading higher overall.\n\nBut again, it's just one of many indices. Other indices — like the NYSE composite, the S & P 500 and the NASDAQ 100 — serve as at-a-glance indicators of other segments of the stock market.",
" There are a variety of stock exchanges across the world. In the US, the biggest are the NYSE, AmEx, and NASDAQ. Each exchange has rules for companies that want to list their stock in their exchange, but, assuming the rules have been met, a company can choose whatever exchange they want. (There are some companies whose stocks are listed in multiple exchanges at the same time, but they're uncommon.)\n\nThe Dow, more formally the Dow Jones Industrial Average, is a collection of 30 stocks from across multiple exchanges intended to show how the stock-based economy is doing in general. The stocks are chosen by the people who run the DJIA and are intended to be market leaders in a variety of different industries.\n\nNASDAQ also runs a similar index called the NASDAQ Composite that is comprised of basically every stock listed on that exchange. The NASDAQ exchange is significantly populated by modern technology companies like Apple and Google, so the index is generally noted as how well the computer and related technology industries are doing."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
If a person who is the age of consent has sex with someone one year under the age of consent, does it count as statutory rape?
|
[
" Depends on the specific laws.\n\nSome places have laws that treat it as a hard limit. If the age of consent is say 18, that means anyone having sex with an under 18 year old is breaking the law. Even if that person is only 19.\n\nSome other places treat it more as a gradated thing. There is generally a lower age limit under which all manners of sex are illegal (say 14), then a period where it is legal to have sex with someone else who is within a few years of your own age (say, between the ages of 14 - 17, you are fine having sex with people that are no more than 4 years older than you) and then there is an upper limit above which you are free to bone anyone above that (in this example 17+). So that would mean in this fictional example that a 13 year old could never have sex legally. A 16 year old could have sex with a 19 year old but not a 63 year old. And a 18 year old can screw a 109 year old man for all the law cares.\n\nYou'd have to check the laws in your particular area to know for certain."
] |
[
" Depends on the state/country and their ages. Of importance to note, age of consent (when one is considered old enough to legally decide to voluntarily have sex) and age of majority (age when one is no longer considered to be a minor, but instead is an adult, legally responsible for all of their behavior) are often quite different.",
" Anywhere we draw the line it's going to be weird and problematic. If we put the line at 14 and a 14 year old has sex with a 13 year old, are they a pedophile? Should they go to jail? Of course not - they might even be classmates in 8th grade, with birthdays two weeks apart. But if a 40 year old has sex with a 20 year old, that's actually weirder, even though both of them are clearly 'age of consent'.\n\nIn some places, they make laws that cover an 'age range' for what's legal, so that you can't have sex with anyone under 16 if you're over 18, for example. Other places though have laws that specifically prohibit discrimination on the basis of old age, where it would be unconstitutional to say that a 70 year old isn't legally allowed to do something a 17 year old is.\n\nSex is a complex issue. The need to allow kids to have sex with each other without going to jail, the need to prevent adults from taking advantage of children, and the need for states to follow their own basic laws on rights and fairness often come to a hard compromise on the age of legal consent. It's not an issue that any society has really answered perfectly, and one that's constantly evolving."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What is the difference between a 2 in 1 shampoo/shower gel and the separate soaps? Is it just a mix of both? And is there any danger in washing my body with shampoo or the other way around?
|
[
" 2 in 1s use a thing called coacervates, where conditioning polymers are wrapped around the surfactant micelles (the thing that does the cleaning). When you put it on your hair, the micelles clean the hair of grease and dirt. When you rinse it off, it eventually becomes diluted enough for the polymer and the micelles to separate and the polymers stick to the hair to condition it. The separate shampoo and conditioners basically have those two things separated. It’s been the experience of most people including me that 2in1s aren’t as good as the separate shampoo and conditioner, so don’t bother with it. \n\nYou can use a regular shampoo to wash your body or a body wash to do your hair, it won’t really damage anything. They both use surfactants to do the cleaning and the formulations aren’t super different. If you have colored or styled hair, it might still be better to use shampoos and conditioners made for that because styling and coloring do a lot of damage, and those products have some extra ingredients to try and mitigate some of that damage that body washes don’t have.",
" 2-in-1 shampoo and conditioner is just shampoo plus silicone. The silicone clings to your hair and lubricates it, which functions as the “conditioner” in this scenario. \n\nAs Mitch Hedberg said, 1 is not big enough for 2, that’s why 2 was invented. It’s basically a cheat to get one product to do both functions. Silicone is not a good conditioner. Also, it’s a bitch to clean out of our tanks, and bad for the water system.\n\nSource: engineering manager for one of the largest contract manufacturers of soap and shampoo in North America."
] |
[
" Hand soap I'm not sure, but I think I can explain a bit about body wash and shampoo. \n\nLook on any shampoo or body wash and you'll always see each has a main ingredient, no matter what brand... \n\n\n\nThe active ingredient of body wash (shower gel etc) is sodium lauryl sulphate, an effective (but perhaps slightly harsh) cleaner.\n\nThe active ingredient in typical shampoo is sodium laureth sulphate. This is a modified (less harsh) version of sodium lauryl sulphate, and more suitable for hair. \n\nAt some point in the 80s someone realised that actually the laureth sulphate is still a pretty effective body wash (especially in a shower where the water action helps to clean too). So you could just market it as 'hair AND body wash'. \n(whereas using the harsher lauryl sulphate on hair makes it feel weird).\n\nI just buy the cheapest bulk sodium laureth sulphate I can and use it all over. \n\nThe hand soap I suspect is the lauryl kind, where being a harsher cleaner is more useful. \n \n\nOther ingredients are just scent and color or texture, and have nothing to do with the effectiveness of cleaning you. \nShould you buy the more expensive brands? Nope. \n\n\nThis explanation excludes medicated stuff like anti dandruff and such",
" I've always wondered this too because I have very long hair (down to my butt) and sometimes I run out of my shampoo and end up using some of the 2 in 1 that's in my shower, which basically just seems like shampoo to me. I definitely don't get the effects of conditioner so I always try to avoid it or else my hair will end up being really tangled still."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How do cartoon animators figure out when to make characters blink? Do they keep constant track of it?
|
[
" There's already some really great explanations posted, but I thought I'd offer a counter example for how blinking might be used in animation.\n\nIn live action film acting, actors will generally try to blink as little as possible depending on their character. Strong, unflinching eye contact strengthens a character and the actors performance. People on screen who blink are generally seen as weak. Blinking can distract from the character and the performance. So a good actor can use blinking to his advantage to emphasise a point or certain character traits. A nervous character might blink very frantically, whereas a stone cold killer might NEVER blink on screen, or a persuasive/charismatic character might use blinking to emphasise a point.\n\nSo my point being, the process in deciding those moments in an animation isn't much different, from a storytelling/character portrayal point of view, than in a live action performance. It just takes a little more consideration and planning because it's all comes from scratch rather than second nature from a natural performance of a character.\n\nHere's an oversimplification, but it's kinda like the difference between a beautifully improvised song, and a song that took months to score. They function under the same principles, but one took more preparation and practice the other took more planning and foresight, not that those things are mutually exclusive.",
" They keep constant track of everything, the characters aren't going to remember to blink themselves. Tedium is an accepted part of the art form"
] |
[
" Every frame of a cartoon is drawn. In order to make this process more efficient, a single background image consisting of all of the nonmoving parts is made and copied a whole bunch. Then each frame of moving stuff is drawn on to that background. This saves them from having to redraw the same never-moving bench a hundred times, and keeps the background consistent.\n\nSometimes there are holes, or the moving part on top of the non-moving part isn't dark enough to fully cover the non-moving part.\n\nThis is also why you can also spot which part of a wall is going to break when it's slightly off-colored.",
" They record the voice first.\n\nThe main reason for this is because of timing - the animators can't accurately animate the mouth moving and any gestures that go along with the dialogue unless they can accurately sync it with the audio."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Alchemy
|
[
" Alchemy was a form of science/magic where practitioners (called alchemists) would try to transform things of low value into things of high value, usually gold. It didn't work, for obvious reasons, but we learned a bit about actual science in the process."
] |
[
" Conspiracy theory about Freemasonry began very early in our existence. In the 18th century, preachers would outline what they thought were the evils of most philosophical societies on street corners. The Catholic Church took an institutional dislike to the idea of people aligned with enlightenment ideals (seen as antithetical to the Church) meeting on a regular basis.\n\nBut it wasn't until the late 19th century in the US when dozens of Fraternities reached such heights of popularity that a large fraction of people belonged to many at once, that anti-Masonic conspiracy theory jumped the shark. With the publication of several screeds making wild claims about Freemasonry and culminating in the infamous [Taxil Hoax](_URL_0_), the meme began to spread that there was some sort of link between the worship of dark forces and Freemasonry.\n\nThis, in turn, lead to what I consider the masterpiece of paranoid conspiracy: the \"found\" letter from a figure of importance in 19th century Freemasonry named Albert Pike and a shadowy cabal of Masons that prophetically predicted WWI and II (oddly, the letter was claimed \"found\" in 1946) and connected the claims of the Taxil Hoax with those of the Protocols of Elders of Zion, a classic anti-Semitic screed.\n\nMuch later, in the 1970s, Robert Anton Wilson revived an obscure 18th century group called the Illuminati for his *Illuminatus! Trilogy* which cast Freemasons (and dozens of other groups) as the unwitting pawns of a global conspiracy of aliens, said 18th century Bavarians and globalist magicians. It was meant to be funny, but the idea stuck in the public memory and the idea of the Illuminati as it's waved around reddit was born and subtly linked to Freemasonry.",
" Jung was extremely interested in alchemy, a major theme of which is \"uniting opposites\" - or, more poetically, the marriage of heaven and hell. The idea is that a thing divided is an incomplete thing. You cannot be a wholly integrated person without first acknowledging and understanding your negative aspects. That's probably an ELI15 and not ELI5...."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why don't bugs splatter from falling proportionally equal distances as a human jumping off a building?
|
[
" Because they hit the ground with significantly less force because they weigh less (and also because they probably have a very slow terminal velocity).\n\nIf the ground were to hit the bug with the same force that it hits you, the bug would die. If you were to drop just chuck one of your legs off the roof, it also might not break when it hit the ground (don't try this at home, I'm a trained professional). But..if you put the entire weight of your body into the picture, the forces change a lot.",
" It is because of air resistance. Air itself stand in the the way of something falling and reduces the speed at which it falls. For humans the maximum speed we can fall is about 120 (if we are speed out wide and not tucked in tight). Cats can only fall at about 60 MPH, and bugs are considerable less than that.\n\nSo slowing falling speed, less impact, bug lives."
] |
[
" Because insects have a proportional larger surface area than volume, where volume equates to weight and surface area is proportional to muscles which equates to more strength. Also insects have \"hooks\" in their legs that allows them to stick to rough surfaces.",
" The weight of a bug scales as the cube of the the length of the bug. A bug twice the length of another one will weigh 2^3 = 8 times the weight of the smaller one if they are exactly scaled.\n\nSmaller and thus, lighter bugs will be pushed away by the flow of air you are displacing with your hand when you are swatting it. Larger bugs won't be displaced as much and your hand will actually hit it, transferring enough energy to kill it.\n\nAn example is if a moving car hits a suspended piece of paper vs a ball. The piece of paper is much lighter and will be swept away from the air moving past the car. The ball won't move as much due to the air and will bounce off the moving car, flying far away."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why can skiers travel faster downhill than human terminal velocity?
|
[
" Terminal velocity is based on air resistance. The quoted value of human terminal velocity is likely based on a normally clothed individual falling face first with their body square to the direction of travel. If they turned so were falling either head first or feet first, they'd probably fall quicker. Likewise the clothes they're wearing makes a huge difference; the looser they are, the greater the drag \n\nThe skier was likely wearing aerodynamic clothing with an aerodynamic helmet and in an aerodynamic posture, all to reduce drag and allow them to \"fall\" (ski) faster",
" They can't. An objects terminal velocity depends on many things, including body position, air density, clothing, etc. \n\nA skier positioned like a bullet has a _faster_ terminal velocity than a jumper spread eagle. If a skydiver were to get into position explicitly for speed they would surpass the skier."
] |
[
" Terminal velocity is based on the density of the air. Normal skydivers are jumping from an altitude where the density is only slightly lower than on the ground. Therefore, the terminal velocity is around 120 MPH.\n\nIf a human were to enter the earth's atmosphere from space, the terminal velocity would be much higher due to the lower density (and, this velocity would decrease as he entered denser air).\n\nA key factor is how fast he was going prior to entering the atmosphere. If he had been in orbit (17,000 MPH), he would most likely burn up. However, if he had been dropped from just above the atmosphere, I doubt that he would achieve a high enough velocity to burn up.",
" If you watch at the beginning of a run, you'll see that the skier always skates a bit out of the gate. A few really aggressive pushes against the snow to get up to speed. That speed will be faster if the racer is stronger, which is typically true of men as compared to women. A huge amount of time can be cut off a run simply by having a quick start. Furthermore when you are going 30-40 mph around a turn it takes a lot of strength to push back against the centripetal force, so a racer can maintain a higher speed if they are stronger. Being heavier helps men maintain higher speeds as well. When you watch the racers make turns you will see that in order to take the tightest line around a turn, a racer will often run into the gates. If the racer is heavier they will have more momentum and therefore hitting these gates will slow them down less."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Difference between murder and aggravated murder?
|
[
" Murder is killing someone.\n\nAggravated murder is killing someone for a particularly bad reason or in a particularly bad way - for example: you were paid to do it, the victim was a judge or a police officer, you used a bomb, etc.\n\nDetails will vary by jurisdiction, but here's a list of aggravating factors for Oregon:\n\n_URL_0_"
] |
[
" Crimes are weighed on how the actual situation applies against the laws. \n\nAttempted murder would pertain to someone who stabbed someone, not in hopes of killing them, but wounding them, intimidating them. People also sometimes stab people to kill. How would you sentence these two people? He didnt mean to kill him, but he used a weapon capable of killing.\n\nWell there is no law differentiating between these two. So in a blanket sense this law applies to both, so a median sentence was passed to deal with less severe, but still potential murder scenarios. However, since they didn't die its not murder or manslaughter.\n\nLets say you only wish to wound someone, and then they die. Its would be attempted murder, then it would become murder. The biggest difference is they died.\n\nHowever the sentence of manslaughter can come in between these two extremes as well. The biggest difference is provable intent. A bullet that came close might not be aimed to kill. But to wound.\n\nExcessive force scenarios that could result in death are covered by attempted murder as well. Like using a firearm on a unarmed assailant. if self defense isnt provable, it becomes attempted murder.\n\nAll in all, intent isnt proof of a crime. Until there is a murder, there is no proof murder was the intent.",
" Murder : one human killing another intentionally and not in self defense \n\nHomicide : one human killing another \n\nManslaughter : accidental Homicide \n\nMassacre : a very one sided battle \n\nAssassination : planned murder of prominent figure for political reasons."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What is a crush?
|
[
" [The infatuation part is what people usually mean when they say \"crush.\"](_URL_0_)\n\nBasically you make him feel good. Because you make him feel good, he wants to spend as much time with you as possible to get as much \"good feel\" as he can.\n\nIt's like finding a new flavor of ice cream that becomes your favorite."
] |
[
" This seems like the kind of question in psychology that could have many answers and factors.\n\nThe only thing that comes to mind is that when with your crush, your endocrine system releases a lot of different hormones/neurotransmitters into your circulatory system and nervous system. When a neurotransmitter is secreted and received by a neuron (brain cell), it is then lodged into the receptor, and has to be digested down or taken in and reused, which then can cause dependancy\n\nLook at it this way: Your brain gets used to having so many \"love juices\" flowing through it while being near your crush, that when you are no longer near the person of interest, your brain feels crappier than usual\n\nIm sure there is a better bio/psych reason than this, but this is how i see it",
" You can watch the documentary \"The Weight of Chains\". You will learn a lot about Kosovo and the crush of Yougoslavia."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does facebook need two apps, one for messenger and one for general use?
|
[
" It doesn't need two apps, it's for convenience. We used to message people through one Facebook app which was very cluttered with status updates, all sorts of drop down options and a chat box at the bottom. \nHaving a dedicated messenger application and a dedicated app for scrolling was all about convenience.",
" And one to track pages. One as their own photo messenger. One for selfies. One for one type of video. One for another. One for work chat. One for work. One for the list of all 17 Facebook, inc. apps in just the iOS app store, 16 not counting F8 which makes some sense. Back to 19 adding Instagram's 3 apps.\n\nThey have a problem."
] |
[
" There are many reasons. A major reason is that Facebook is trying to position itself as an Identity Provider. They want other companies to integrate their website with Facebook to let people authenticate / register accounts on those third-party websites using their Facebook identity (ever see those 'Sign-in with Facebook' options on non-Facebook sites? - That's what I'm referring to). \n\nThird-party websites are interested in identity providers which can\n\na) offer a convenient way for users to securely register/log-in\n\nb) cut down on the number of automated/spam accounts created\n\nc) provide some sort of identity assurance (that the person is who they claim to be)\n\nFacebook wants to tick off all three of those objectives where as many other Identity Providers can only hope to reach that goal.\n\nBy cracking down on fake or potentially fake accounts, they make Facebook much more appealing to companies looking for an Identity Provider.\n\nAdvertisers will also be more interested in marketing through a platform where they have some assurance that the users who view their ads are real people and not, for example, bots / automated accounts.\n\nSo basically Facebook is building up a reputation of being a reliable Identity Provider that has genuine user accounts tied to individual people by name (and typically mobile phone number etc.).",
" Its reasons for doing so are now clearer: Messenger is becoming a beast of an app, with its own links to outside businesses and software apart from Facebook's main site.\n\nAt the company's F8 developer conference this week in San Francisco, executives pulled back the curtain on the new Messenger. It's now a storefront and a platform for other mobile apps, which can be downloaded from within Messenger and integrated into people's Messenger chats. There are more than 40 outside app partners already aiming to spice up users' conversations with things like personalized GIFs, tools to turn your texts into songs, and even sports animations from ESPN. The apps can be accessed by hitting the \"...\" button on the Messenger compose screen.\n\nUsers can still send each other plain old text-based messages. But why do that when the Messenger app Ditty can turn your text into a song? Or when you can superimpose fire onto your friend's house with Pyro?\n\nThese sorts of integrations, Facebook CEO Mark Zuckerberg said at F8, are meant to give people more tools to express themselves and to better say what they want to say.\n\nAlso, Facebook is now positioning Messenger as a business platform. Soon, when people buy things from select online retailers, they'll be able to sign up for updates like shipping notifications from within Messenger, or chat with the retailer there, or even change their order. Facebook thinks this is better than having to use regular email or phone calls to engage with the business. Facebook's initial retailer partners include Zulily and Everlane.\n\nSource: _URL_0_"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
how can I tell the difference between a star and a satellite with my naked eye when looking at the night sky?
|
[
" Here's a quick guide:\n\nSatellites move - quickly enough that you can easily see them moving.\n\nStars twinkle (because the atmosphere distorts what are point sources of light, making them appear to twinkle).\n\nPlanets don't twinkle (they're big enough and close enough that the atmospheric distortion doesn't have much of an effect)."
] |
[
" If you're looking with the naked eye, seeing a stationary satellite would require a combination of perfect viewing conditions (i.e., far away from civilization and its light pollution) and lucky geometry (the sun bouncing off of it at the right angle). Geostationary satellites usually fall around a magnitude of +11 or dimmer, while best-case middle-of-nowhere naked eye viewing allows you to see +6 or +7, and higher is dimmer.\n\nEssentially, if you live anywhere near people, it'd be incredible to see a satellite that wasn't moving.\n\n[Source](_URL_0_).",
" They kind of do to the naked eye, but only because they appear very small, and 4 times larger than extremely tiny is still very small. But really there's quite a bit of apparent size variation if you pay close attention. It may help being away from light pollution. But the stars that are bright in our sky also appear larger.\n\n[Here's animage of Orion's belt](_URL_0_) which is about what you can get with the naked eye. You can see that the dimmer stars are like a single pixel, while you can make out a round shape of the brighter ones. \n\nEdit: ack I forgot to hit save when I resized that. If you looked at the image before this edit, then it was obviously a lot larger than how it looks to the naked eye. Fixed now though."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
The state of NJ just issued a state-wide travel ban. How are travel bans legal?
|
[
" New Jersey is under a state of emergency. Governments can ban you from doing pretty much whatever they'd like during a state of emergency, if the ban is necessary to prevent people from being hurt.",
" Because it's a matter of public safety. If you're on the road during a blizzard and you get into an accident, now the police and rescue workers have to risk their asses and waste their time pulling you out of a ditch or somehow get you to a hospital. It's not an easy thing to do during a blizzard.\n\nAlso, the state/city workers need to plow the roads and truck the snow out. That's a monumental task when 2-3 feet of snow piles up overnight. They can't really do their jobs if idiots are driving around for no good reason, getting stuck, and causing accidents.\n\nA travel ban makes it so that only someone with a life-or-death emergency has a reason to be on the road. Even doctors and other essential personnel won't be on the roads -- they'll be sleeping or staying in the hospital until the ban is lifted and the roads are safe enough to travel. My mom works at a hospital and the staff stays put. They all bring changes of clothes and toiletries, there are plenty of beds and showers, and the hospital is stocked with food. There is no reason to leave aside from an actual emergency."
] |
[
" Most people's only impression of New Jersey is the NJ Turnpike, which looks like [this](_URL_5_) and sometimes smells from the oil refineries (plus side: cheap gas!). If you get off the Turnpike, you'll see stuff that looks more like [this](_URL_6_) or [this](_URL_7_). There are certainly bad places, but there are bad places in every state. NJ's happen to be on the most heavily traveled road (by outsiders).\n\nThe people in NJ are generally very proud of their state, and are likely to defend it. That pride and defensiveness is amplified when people use unfair stereotypes about the state. That makes them seem angrier.\n\nI've lived in NJ my entire life. I love it, and will defend it as long as it takes.\n\nEDIT: [This guy](_URL_8_). Screw him",
" New Jersey is the most diverse state in the US. We also have/had a lot of factories and plants in north jersey. North jersey also houses a lot of people who work in NYC, because paying 150 bucks a month for transportation and about 1000 for rent in a really nice place is much cheaper than paying about 1500 for a shithole in NYC.\n \nNew Jersey also has one of the best transit systems in the states, and as such will create pollution. In my area a Car is completely optional to get anywhere town in North Jersey.\n\nPeople say NJ is bad because of all the \"Guidos\" and the other Stupid bullshit the media says about it.\n\nSouth Orange, Maplewood, Parts of Newark, Camden, Linden, you can have a mush better time in Jersey for WAY cheaper than NYC. all NYC is is a tourist trap with lots of shops for international travelers to blow their money on."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How do archeologists and paleontologists look at a specific bone and figure out what animal it belongs to?
|
[
" It's a game of elimination really. Scientists can date a bone so you know roughly white time period any given fossil is from. That excludes any known animal not around in that time period.\n\nYou can compare the bone to any known animals alive or dead. If you find a close match, you can start looking into more detail to see if it's an exact match. Even if you can't find a match, bones are shaped by their function. If this bone is not a match but similar to bones of existing or other extinct animals. You can get an idea of the function and placement of this bone in the animal's body.\n\nThere's a lof of animals that we have no clear idea of what they looked like because all we found is a single bone. If we ever find more, we can expand on that knowledge but until then, they're a mystery. There's more than a few dinosaurs that have cryptic names that refer to the one body part we found of them. Animals whose names translate to 'terrible claw' and things like that.\n\nAnd to make it even more complicated, animals sometimes undergo significant change as they mature for from juveniles to adults. It happens that we adjust our expectations and two different species actually turn out to be the same species. Just with significant differences between male and female or juvenile and adult."
] |
[
" Ah, this is where an archeology degree with perhaps a minor in zoology comes in. \n\nThey can make educated assumptions of how the dinosaurs sounded by looking at the skeletal fossils. It had a rib cage this big, so it had lungs and a diaphragm so big, it had a neck/vocal box roughly this big, so if it made sounds it might be like _this_, and voice box/vocal chords in this shape, so it probably made sounds like _this_. \n\nTrue, noone really knows exactly how each of the dinosaurs sounded like.. but looking at the anatomy of the dinosaur, based on its fossilized remains allows them to reconstruct what its fleshy bits might have been like and thus make some educated guesses (based off the animals we have around now) to what it sounded like, how it moved etc. Its a little bit how a forensic scientist can rebuild a facial profile of a cold case victim or a frozen neanderthal based purely from a skull. Really neat stuff.",
" We study the physiology by either physically reordering the bones into their original positions, or putting them into a computer model (which can even simulate their movements if you program in tendons as well). Physiological observations help us to determine how a fossil is related to similar specimens, and radiometric dating helps to put it all in order.\n\nWe have not been able to extract viable DNA from dinosaur fossils; fossilization is already a rare process with most organisms decomposing entirely, so the chances of testable DNA being found are quite slim. We can, however, learn more by finding better-preserved specimens like when we found the feathers on Kulindadromeus zabaikalicus.\n\n & #x200B;\n\nEdit: \"viable DNA from \\[dinosaur\\] fossils\""
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How would a democratic president pass laws with a majority republican senate?
|
[
" The President doesn't pass laws. The President signs bills that have been passed by both houses of Congress into law or vetos them. \n\nHowever, the President is generally the leader of her party and can set the party's legislative agenda. For example, if Hillary is elected she could get Democrats to focus on passing a new immigration bill and use all of her influence to try to get Republicans in Congress to compromise on the bill, but she can't do anything else about it. A Congress member will still have to introduce the bill and Congress will still be the one to make changes to it.\n\nHillary could tell Congress \"if you put that in, I'll veto it\" and that might affect what Congress does, but Congress doesn't have to listen to her.\n\nTypically what happens is the party evaluates what it thinks it can get passed through compromise and focuses on that. However, there is almost always a decrease in the number of new, major laws that are passed when Congress and the Presidency are controlled by different parties.",
" The president doesn't get to \"pass\" laws. He or she can sign laws (or not sign them, and they may become law regardless).\n\nThe legislature is the House of Represenatives (the House) and the Senate. The House and the Senate create the laws, then they send them to the president, if the president disagrees then the House and the Senate can vote again and if enough people vote in favor then it will become law regardless of whether the president agrees.\n\nAll of that said, the president has a lot of influence. He or she gets to represent the country and can talk about why XYZ law is super important and try to get the public to agree. If a particular Senator or Representative (member of the House) is disagreeable, then the president can try to get the people to support an opponent in an upcoming election.\n\nThe term is \"bully pulpit\". It means that when the president speaks then people are going to listen and be influenced. It will be more difficult if the opposing party control the Congress (Congress means the House and the Senate) but the president will still be able to have influence by using the bully pulpit."
] |
[
" Congress has two chambers, the House of Representatives and the Senate. A bill that is going to be signed into law must pass both chambers before the president can sign it into law. If one of the chambers doesn't pass it with a majority (51% or more) vote, it won't become a law.",
" Both senators and congress members can start a bill through the process. A bill must pass both houses and not be vetoed by the president, and then it becomes law."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How Canada Works
|
[
" [I'll let Rick Mercer explain it in a much more entertaining way than I could](_URL_0_).\n\nCanada is a Constitutional Monarchy and Parliamentary democracy. The Head of State is the Queen but seeing as she is British and doesn't live in Canada the Governor General is appointed to act in her place. While a lot of power technically lies with the Governor General and the Crown in practice the position is largely ceremonial and those powers are only exercised \"on the advice of the Prime Minister\". Basically the Prime Minister and/Parliament makes the decisions.\n\nLike the USA Canada has three Branches of Government. The biggest difference is that the Executive branch come from within the Legislative. It would be like if the President had to be a congressman. The House of Commons is fairly similar to Congress in that Representatives/Members of Parliament (MPs) are elected to represent their districts or as we call them ridings. The party that holds \"the confidence of the House\" (basically a majority of MPs support them) gets to form the Government. That also means should they lose a key vote like the Budget the Governor General will dissolve the House and call an election. The Prime Minister is the head of the Executive branch and is leader of the Party forming the government. The Ministers responsible for various departments (essentially you Secretaries of ...) are also chosen from the MP's of the governing party."
] |
[
" Land itself doesn't make money, but it is a component in making money. So, Canada has the ability to produce a lot of resources because it has a lot of land, but it is restricted in other ways like capital and labor since you need people to take the resources out of the ground and capital to pay for the machines to do so as well. Also, Canada's resources are in remote areas, adding additional transportation costs.\n\nThe resource extraction industries are completing against other industries, like heavy manufacturing. Having both industries in your country doesn't mean you have more money in general because both industries are competing in your country for labor and capital. That is why Canada is just at developed nation wealth.",
" 1. Canada is not a global military power engaged in various violent conflicts around the world. Canada has not historically meddled in the affairs of foreign peoples (except the indigenous people of Canada, of course).\n\n2. Canada has more expansive social welfare programs. Canada has free universal healthcare and provides cash welfare to more of its poor than the US does. The effects of this are hotly debated but many would argue this more effectively ameliorates the negative effects of extreme and concentrated poverty.\n\n3. Canada doesn't have quite the same history of violent race relations as the US. Of course, like in the US, there were massacres and dispossession of the native population, and to this day the indigenous population are disadvantaged, but Canada didn't have the history of mass slavery and structural white supremacy as the US does. Racism is a problem in Canada, especially against the First Nations (who represent a greater percentage of the total population in Canada than Native Americans do in the US), but there isn't the same massive class of racially oppressed people suffering from a history of exploitation and poverty like there is in the US."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
if gravity is gets weaker the further away you are from a large mass, why can't rockets leave the earth by just flying at a low constant speed?
|
[
" Preface: \"Escape velocity\" defines the *initial* velocity an entity needs to get infinitely far away from a planet (or sun or whatever). Gravity will do work on the entity and slow it down during this journey. At the entity approaches an infinite distance away, it's velocity will approach zero.\n\nNow, assuming you are comfortable with that:\n\n > shouldn't you be able to just fly straight up into space at a low, constant speed?\n\nYes, you can. It's extremely inefficient though.\n\nConsider the energy required to hover above the ground versus the energy required to just...stand on the ground.\n\nThe former requires helicopter-levels of fuel consumption (much more in the case of a rocket) while the latter requires essentially nothing.\n\nThe solution is to get out of the deep part of the gravity well (it falls off as the square of distance) as fast as possible, so you don't waste energy hovering."
] |
[
" There isn't really a reason. That's just how the universe works and it can be experimentally shown that it does work. I could tell you that acceleration due to gravity is constant because the force of gravity is proportional to mass, but you could just as easily ask why that is and we'd be essentially back to square one.\n\nIn your example a feather will fall slower than a brick but that's because a feather has much greater air resistance per unit mass. If you remove air resistance (such by dropping two objects in an evacuated container or on the moon) they will fall at the exact same speed.",
" anything orbiting earth must be traveling that fast (the exact speed varies by orbiting height, lower you are, faster you need to go to orbit), infact reaching that speed is a substantial part of the rockets job. Its why we cant just float up on a balloon or plane and chill, once your at altitude, you still have to get moving sideways really freakin fast. If you watch a rocket launch, you'll notice its basicly flying sideways not too long after takeoff, just get past the densest atmosphere and get moving sideways as you finish your climb.\n\nAs for coming back down, pretty simple, just tap the brakes and you'll start falling, the atmosphere will slow you down the rest of the way."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What is the differences between confidence, self-esteem and bravado?
|
[
" The intensity (and intent).\n\nBravado is exaggerated confidence meant (intentionally or not) to impress or intimidate, while confidence is not specifically externalized at all.\n\nSelf confidence is the trust in skills or skillfulness, while self esteem is a sense of self worth.\n\nYou can be an excellent salesman and confident, but not consider yourself a good person (or a person of worth)\n\nMake sense?"
] |
[
" Confidence doesnt come from knowing how to do things. Confidence is a lack of fear of failure. Alcohol inhibits logical thinking and so we have trouble seeing how an action will go wrong. Without worring about the potential negative consequences we appear confident. \n\nThe best way to gain confidence outside of drinking is to try doing a bunch of things you'll fail at. We are brought up to fear failure, but the reality is that in non-life threatening circumstances there is nothing wrong with it. The more you try new things and fail, the less scary failing becomes. Eventually you are willing to give anything a try, not because you know you'll be successful, but because you know that failure doesn't hurt as much as missing out on new experiences.",
" Alcohol reduced inhibition, lowering common sense and raising one's sense of bravado and courage. Overall, lower control of one's emotions."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does anyone in the US care about Iran at all?
|
[
" Why does the US care NOW about Iran?\n\nThree reasons:\n\n1: They keep threatening Israel and Israel spends a lot of time & money cultivating US politicians to provide a layer of defense against aggression.\n\n2: The US needs oil to flow out of the Persian Gulf to ensure a reasonably free market price for energy, although that need is rapidly (and surprisingly) reducing. Iran can credibly threaten to block that flow.\n\n3: A lot of people in the US with no knowledge of the history of US/Iranian relations only know that Iran took American hostages and basically got away with doing so.\n\nBonus 4th reason: The Saudi Arabian government has put the US government on notice that if Iran develops a nuclear weapon the Saudis will arrange with Pakistan to get their own bomb. The Saudis and the Iranians are the current manifestations of a schism in Islam that are fighting a 1,400 year old proxy war to determine the \"correct doctrine\" for Islamic religious practice. The chances that a limited nuclear war could be fought by those two states is non-zero, and that scares the hell out of US leadership.",
" Because they are a major player in the Middle East, and control strategic points such as the Straits of Hormuz, through which much Middle East oil passes on its way to the USA. They haven't been \"some random middle east country\" for at least the last century. Have a look at a map: it is the world's 17th-largest country, roughly 4x the size of Iraq (or California). \n\nIn case you haven't seen the news recently - relations are definitely thawing. It's pretty well-understood that the Iranian regime doesn't fully represent the people of Iran, who are actually quite keen on American culture (Coca-Cola, blue jeans, motorsports), and Soccer is huge there too."
] |
[
" This was a *default judgment* that was automatically granted to the claimants. Iran never showed up in court or attempted to defend itself because US courts don't have jurisdiction over foreign governments due to the international legal principle of Sovereign Immunity. \n\nThe US has been trying to make an exception to the principle of So ereign Immumity to allow suits against specifically named \"terrorist states\" (Israel and friends are of course excluded) under its own somestic Us laws, thus permitt8ng such suits, but note that at the same time the US insists on protecting its own sovereign immunity and so the US can't be sued in Iranian (or any other nations') courts.\n\nAll lawyers in the US have to do is file a complaint making all sorts of claims, pay some \"experts\" to support the claims, and then wait until a trial date is set. When the Iranians don't show, the judge auto.atically grants judgment in favor of the claimants. The hard part was trying to actually collect money. Foreign govt won't accept test jushments as being legal so the only source of mone u to take is what Iran has had frozen here in the US under sanctions laws which until now we're deemed to be out of reach.\n\nOf course the goal of these suits was not to help terrorism victims as much as it was to create further obstacles to improved US-IRAN relations, which is why AIPAC pushed for these laws that allow such suits in violation of international law.\n\nIf the Iranians were to start doing the same they could sue many US govt, officials as well as corporations that for exams were cooperating with Sadam in launching chemical weapons against Iran which resulted in 100,000 casualtirs, or about 30 times 9-11.",
" Because Iran will back Syria, and Iran is one of the only nations left on earth willing to trade oil for something other than U.S. currency. Almost every other oil-producing nation, by treaty, is required to accept only US Dollars in exchange for it. This forces potential purchasers to trade with the US for the dollars that they then give to said oil-producing nation. Dollars traded for this purpose have become known as \"PetroDollars\" which you may or may not have heard of from economic news shows.\n\nUntil recently, there have only been a few nations which accepted non-US Currency for their oil. These nations were Venezuela, Iraq, Libya, and Iran. Iraq and Libya have both changed their minds recently due to what one may call \"outside pressure\" which leaves fewer and fewer direct lines of trade for nations wishing to avoid the American monopoly on it. If the US strikes Syria and Iran doesn't back down, the US will almost certainly strike Iran immediately afterwards. This puts one of the only two remaining major non-Petrodollar oil exporters in extreme danger of \"outside pressure\" to change. By confronting the US over Syria now, Russia, and to a lesser extent China, is hoping to make the US back down and, thereby, save Iran from involvement and potential attack. Arming the Syrians also increases the cost of such an attack, which further helps to incentivize the US into hopefully backing down.\n\nEdit: Of course, another avenue Russia could take is to try to talk Iran into cutting its ties with Syria prior to any attack by the US, which would protect Iran by disassociation. Of course Iran has absolutely no interest in throwing Syria under the bus like that and has issued statements to make that clear. Thus, short of a diplomatic yahtzee by the Russian Ambassador in Tehran, Putin is back to protecting Syria as his only option.\n\n**TL;DR:** If the US attacks Syria, Iran will respond and the US will attack Iran. Russia and China both need Iran to get around the increasing US trade monopoly on oil. Putin isn't going to bat for Assad, he's doing it to protect Iran, which has become a critical trade partner for Russia."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do hot showers dry out your skin?
|
[
" Your skin is kept moisturized by oils in and near the surface. A hot shower can strip these oils. That allows the moisture in your skin to dry out."
] |
[
" I don't think that the top answer about humidity is the most important factor. Your body sweats as a response to both heat and humidity, and 100F+ air temperatures are uncomfortably how even with low humidity, such as summers in the southeast US. Also, the air surrounding you in a hot shower is very humid, basically 100%RH, and this condition is much more comfortable than 100%RH at the same temperature outside would be, due to the liquid water conducting heat away from your skin.\n\nYour body is 98F inside, and produces heat as a byproduct of various metabolic processes, which is rejected from the body through the skin. The rate that heat transfers from your skin depends on the temperature, humidity , and velocity of the air that surrounds you, or the temperature and velocity of the water that surrounds you in the bath. Air at 75F and 50%RH usually does a good job at removing the heat from your skin at the same rate that your body is producing it. \n\nAir is a better insulator than water, while water is a good conductor of heat. Therefore, when your 98F body is surrounded by only slightly cooler 95F water, the heat rejected from your body to the water moves away from you very quickly, and by keeping the temperature just a few degrees colder than your internal body temperature, the rate that heat is removed through your skin equals the rate that your body is generative heat. You may prefer water a few degrees warmer than your internal temp because you are partially exposed to colder air, and sweating in the shower opens up your pores and feels good.\n\nTL;DR It is because water is a better conductor of heat than air. \n\nEdit: My source for the explanation above is from what I learned in various undergraduate and graduate engineering heat transfer classes. I am also a licensed professional engineer, and I took my licensing exams in HVAC.",
" It’s actually because of evaporative cooling. Your body releases small water molecules through skin pores all the time. Even at the same temperature the dry wind sucks some of the fastest moving (hottest) H2O molecules thus cooling you down. That’s why hot dry air feels cool but humid hot air does not."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How come PCs need anti-virus software but phones and tablets do not?
|
[
" Windows has been around for quite a while, and a lot of it's basic functions were designed before people even had dial-up as a common thing so viruses were far less a thing. One major issue is that it's challenging to tighten up it's security without breaking compatibility with existing programs. Since viruses and other malware are programs, once they get running they take advantage of anything they can. Windows will also run programs obtained from basically anywhere, though it'll bark a warning first.\n\niOS however, will ONLY run software from the App Store (which has been thoroughly checked out) and Android by default behaves the same (though you can change that). Both also have a \"feature permissions\" model where if programs want to do something potentially naughty, they *must* ask the user before doing it. Both platforms also seriously limit what programs are allowed to keep running in the background. Windows will keep letting things chug along but iOS and Android require stuff register to keep running in the back, and they're still subject to a lot of rules and limits. Since most viruses need to run in the background to do their naughty stuff quietly, this corks that risk too."
] |
[
" This is an excellent question OP and I am going to try to offer a partial answer - on security in phones. For a start, any mobile device which has a CPU, RAM, an OS, and an ability to connect with other devices is at risk. \n\nThis includes, cell phones, tablets, some cameras, some in car systems, etc. Those devices are not inherently resistant to security threats but are less of a target for some kinds of attacks (e.g. large scale malware and ransomware) because the people who initiate the attacks normally want to be paid and they can't make much by infecting or encrypting data on a phone (that is changing). \n\nAs well, people on phones tend to use apps much more than Web services, and so they are less prone to downloaded malware and some other kinds of attacks. However, phones are much more prone to phishing (email, text, MMS) of all types as phone users tend to take security less seriously than they should and often respond to phishing attempts without thinking it over. \n\nThe fact that most phones ship without security apps is a part of the problem, but the constant use of social media, texting, Cloud and other services from phones is really the bigger issue. People on phones often inter-mix personal data (useful to criminals for things like more phishing attacks, fraud, black mail, etc.) with work data (valuable to intellectual property thieves, corporate spies, nation state actors, etc.). Those people know that an average person is likely to have both types of data on their phone (e.g. business emails sent to the phone, docs stored from work via the phone, into a Cloud folder). \n\nSo, phones are a target and they are under attack. Most of the time, attackers want your data. That is worth more to them than the phone (some exceptions apply). They are less of a target for **some** kinds of attacks but the threats that are on the rise include:\n\n* phishing (as mentioned);\n* Social engineering (convincing users to share sensitive or private information with another person through manipulation);\n* Surveillance of the user and their location/transactions/shared contacts, etc. via text monitoring, audio tagging, metadata collection, GPS, and a lot more. Much surveillance is done because the user agreed to terms of service without understanding them. Some is done by malicious actors though. \n* Malware (on the rise, including to take control of the phone for things like crypto mining)\n* Malicious WiFi hotspots (someone puts up a hotspot so phone users will connect, and then scans their communications looking for something they can steal/use).\n\nComputers are prone to the same stuff, except that most PCs come with built-in security features, especially under Windows 10 and Mac OS X and from Intel (another whole story) and a lot of users install and run Anti-malware software, a basic firewall, etc. to help secure the PC. PCs get hit far more often than phones and the numbers are staggering, so manufacturers tend to take security seriously (e.g. Microsoft).\n\nThe protections in place on phones are unique though as follows:\n\n1. Apple implements security in iOS (running apps in controlled and secure \"sandboxes\"), uses encryption widely to protect user data (e.g. in iMessage) and in hardware (built in encryption hardware, etc. In a nutshell, Apple iOS is a closed system and that makes it much harder for attackers to figure out the inner workings and then plan/launch attacks\n2. Android, as an OS also forces apps to run in a controlled sandbox, runs a hardened kernel (the \"core\" of the OS). and support a bunch of encryption options (some run w/o user notice). Android is implemented on a ton of different hardware though and so things like device access hardware, file segregation, absence of bloatware, provision of security apps, and lots of other things is down the the phone manufacturer (e.g. Samsung) and some do security well (OnePlus) and some don't (you can google that :)\n3. Both also provide tools to find lost/stolen phones, lock the phone, check that apps are signed and from a known source, block apps, protect OS files, etc \n\nThings start to break down if:\n\n1. Users jailbreak their phone\n2. Side load apps from unknown sites (i.e. not Apple or Google)\n3. Don't use a password, facial recog., thumb print or SOMETHING to lock the phone\n4. Share their device with others who may not be careful and diligent about security of YOUR phone and data\n\nAll of those things put your phone at greater risk. \n\nA few tips on what you can do to improve phone security:\n\n1. Set up a phone login and use a strong PIN or password or switch to biometrics...(at least 8 characters for a PIN)\n2. Turn on phone tracing in case it is lost or stolen\n3. BACK-UP important info (e.g. contacts) from the phone to a PC or into the Cloud in case you need to restore it later\n4. Password protect any Cloud accounts with a strong (like 12+ characters) password\n5. Install a password vault so you do NOT save passwords in something like Note or EverNote (bad idea and password vaults are free or cheap)\n6. Install **all** vendor patches and updates, especially if they say \"Security enhancements\". This is a big issue in Android. Many vendors (looking at you Google) don't offer support for older phones. So, people who can't afford a new phone every 2-3 years are prone to newer attacks (because...no patches)\n7. Install anti-malware apps and set them up to auto scan apps, incoming data, etc\n8. Only install apps from reputable sources and check the security/privacy settings for all apps. If you are done with an app or have suspicions about how it is behaving (often hard to know), consider deleting it\n9. Don't use social media apps on the phone. Seriously, they all suck and all (especially some in the news lately) take your data ALL the time\n10. Read up on your phone's security features and apply those you understand (if not sure, read more)\n\nAll of this applies to phones and tablets. Also, I know I didn't fully answer your question so it comes down to this \"more attacks on PCs, because they are data rich and may provide a pay day so vendors offer more security some built in and some you buy\"...but things with phones are getting worse and because phones are the gateway to much more (Cloud, remote to home, banking, etc.) they must be secured. Long post, but I hope this helps. :)",
" Desktops/laptops will never go away because A) they have large displays and B)they have many keys\n\nA is significant because you can have multiple windows, so you might have a task manager open and a browser and a video game behind them\n\nB is significant because touchscreens will almost never be as good at typing as a physical keyboard without having a screen the size of a normal laptop. Also, with two keys i can type \"{\" and \"~\" and still have room for pageUp, pageDown, arrow keys, ctrl, fn, shift, alt and the letters\n\nAlso, laptops are physically larger than phones so they will always be faster than phones and can be more sturdy.\n\nThe reason your phone feels slow is that most of the stuff you are probably doing requires lost of data from the internet, and the speed of pings is directly proportional to size. Also, its harder to see whats going on on the background and to, say, uninstall X program so there may be terribly made, memory-leaking programs installed by samsung that cant be killed or taken off."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
what is actually happening when matrices are being multiplied?
|
[
" When you do the typical scalar product on two vectors, you are essentially adding the contributions of every entry on the vectors to get a specific number. Also, these scalar products are usually written as a (row vector) x (column vector).\n\nSo instead of the usual notation of v.w, instead use v^t w, where v^t is the transpose of the vector, and use the usual matrix multiplication to get the answer.\n\nNow, a matrix is like a list of vectors, written in either row vector form or column vector form, doesn't matter. So when you multiply two matrices, to get the first entry of the resultant matrix, you do a scalar product of the first row vector of the first matrix with the first column vector of the second matrix. You keep doing this for each entry until you get a matrix of scalar products of every possible combination of vectors.",
" Matrix multiplication is really just an extension of the dot product. So first it is important to know what a dot product is. In a geometric sense, the dot product between two vectors is defined as the product of their lengths multiplied by the cosine of the angle between them, this can be visualized pretty well in [this image.](_URL_0_) Here there are two black vectors **X** and **Y** with their tails (their starting point) at the same position. Then there is a third red vector which is a projection of vector **X** onto vector **Y**, the length of this red vector (NOT the vector itself) is the dot product between **X** and **Y**. \n\nOk, so you know what a dot product is but what does this have to do with matrices? Well, we're getting closer. If we do [some math](_URL_1_) we can show that the dot product between two vectors can be written a [little differently like this.](_URL_2_) Now the series format can be a little scary so as a simple example let's take two vectors **A** = [1, 2, 3] and **B** = [4, 5, 6] see what the dot product is. **A** • **B** = 1 * 4 + 2 * 5 + 3 * 6 = 32. So now you can calculate a dot product. But actually, you did matrix multiplication, only in this case you multiplied a 1x3 (1 row by 3 columns) matrix with a 3x1 matrix to get a 1x1 matrix.\n\nNow, what happens when you make your matrix bigger? It's really pretty simple but we need to be careful how we do it. Did you notice that a 1x3 matrix multiplied by a 3x1 matrix gave a 1x1 matrix? Well it turns out we can only multiply matrices A and B (A*B) if the columns in matrix A equal the rows of matrix B. Wikipedia states it well as \"if A is an n × m matrix and B is an m × p matrix, their matrix product AB is an n × p matrix, in which the m \nentries across the rows of A are multiplied with the m entries down the columns of B\". \n\nSo it is helpful when starting matrix multiplication to determine what size matrix you are going to get. If you have a 2x3 matrix called matrix F and 3x2 matrix called matrix G we know that it will multiply since 3=3 and we know that we will get a new matrix that is 2x2 that we will call matrix H. Now all we need to determine is what the value in each slot of the 2x2 matrix is going to be. \n\n Matrix multiplication of F*G = H\n F is 2x3 matrix, G is a 3x2 matrix and H will be a 2x2 matrix\n Row 1, column 1 of H will be the dot product of row 1 of matrix F and column 1 of matrix G. \n Row 1, column 2 of H will be the dot product of row 1 of F and column 2 of G.\n Row 2, column 1 of H will be the dot product of row 2 of F and column 1 of G.\n Row 2, column 2 of H will be the dot product of row 2 of F and column 2 of G.\n\nTo summarize, you are doing the dot product between the rows of the first matrix with the columns of the second matrix. \nIf we have two really large matrices and want to know what will be in row 12 column 45 of their product. We do the dot product of row 12 of the first matrix with column 45 of the second matrix. So the best way to do matrix multiplication is first learn the dot product, then all you need to do is keep track of which row you are multiplying by which column and your value will go in that row and column of your solution.\n\n(Edited for formatting)"
] |
[
" Think of them as a simplification of a matrix.\n\nFor example, let A be a square (number of rows = number of cols) matrix. Let X be a vector (a column) of number from this matrix such that\n\nA.X = k.X. i.e. multiplying the matrix with the vetor X is equal to multiplying the vector with a scalar value k. k is the eigenvalue and X is the eigenvector.\n\nEssentially, you have simplified the matrix A and any matrix multiplication operations involving A into a simpler operation without losing too much of the information.",
" I have only had is described once to me that was a reason. I'll tell you that one even though it is really just math. If you don't know anything about matrices than just ignore this; it won't look like an explanation at all. \n\nWARNING not really ELI5 at all\n\nQuantum mechanics handles things like vectors which are just 1D matrices. Let's look at a simple case. \n\nA single photon of light passes through two slits. If it goes through the left one the vector representing it is \n\n (1)\n (0)\n\nIf it goes through the right one it is \n\n (0)\n (1)\n\nWe haven't done anything but write down how we are going to describe them yet. \n\nWe know from experiment a single photon can actually go through both of them, It sort of splits even though it is just one thing. In that case it could be something like (I know the numbers aren't right but the is still ELI5)\n\n (0.5)\n (0.5)\n\nIf we don't measure which slit the photon goes through it ends up like that, with some through the left and some through the right. \n\nNow if two photons go through they can interact. When they interact we multiply them by turning one on it's side \n\n (0.5)\n (0.5 0.5) * (0.5)\n\nThen we multiply like matrices and we get \n\n (0.5)\n\nOr we get between 0 and 1 photons. \n\nNow let's see how that is different if we measured the photons\n\n (1)\n (1 0) * (0)\n\nwhich gives us (1) meaning a full photon if they go through the same slit. Or\n\n (0)\n (1 0) * (1)\n\n=(0), no photon if they go through opposite slits. \n\nI know I fudged even this simple version a lot but the main idea is that because of the way matrix multiplication works measuring cuts out the cross terms. \n\nSorry I don't know why I bothered writing that out."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do humans get addicted to things that we know are bad for us? (Gambling, smoking, drinking etc)
|
[
" Not so much we get addicted BECAUSE they're bad for us. We get addicted because the feeling it gives us. i.e. adrenaline rushes, release of neurotransmitters like dopamine, social encouragement/praise. The list goes on"
] |
[
" Because Gambling is bad for people. its addictive and can ruin families. im not very against it but we don't need casinos on every corner and there are very valid reasons to oppose them. They have a bigger impact on poor people too.",
" One of the most likely cause of addiction for most people is environmental factors and usually the use of drugs and pornography etc is just to escape our own reality. [This article](_URL_0_) explains this well. \n\n \nAn example from the article: \n > During the Vietnam War Time magazine reported using heroin was \"as common as chewing gum\" among U.S. soldiers, and there is solid evidence to back this up: some 20 percent of U.S. soldiers had become addicted to heroin there, according to a study published in the Archives of General Psychiatry. Many people were understandably terrified; they believed a huge number of addicts were about to head home when the war ended. \n > But in fact some 95 percent of the addicted soldiers -- according to the same study -- simply stopped. Very few had rehab. They shifted from a terrifying cage back to a pleasant one, so didn't want the drug any more. \n\n\n \nNow obviously nicotine and alcohol is not as serious as heroin but people are obviously unhappy or stressed etc."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What is the Glass-Steagall Act and what are its effects?
|
[
" It came about in the 1930s as a remedy to the problems which caused the great depression. One of the main provisions was to seperate investment banks from commercial banks. In other words, a bank could not be your typical bank for people's savings accounts, and also invest in commodities or stocks. \n\nWhy is this bad? Because if Joe Smith deposits his savings at his bank, its FDIC insured. The bank knows that if it loses Joe's money on a risky investment, its the federal government that has to bail them out. So Glass-Steagall aimed to stop that.\n\nEventually the act was repealed in the late 90's and banks could again be both a commercial and investment bank. Some people point to this relaxation as the cause of the 2008 crash/\"great recession\". There have been calls to reinstate the act. Most recently McCain and Warren."
] |
[
" The Glass-Steagall Act was put into place to try to reduce the risks that led to the Great Depression in the United States in the early 1930s.\n\nIn 1999 another act, Graham(R)-Leach(R)-Bailey(R), was put into effect by a veto proof Republican led congress. It reversed some of the aspects of the Glass-Steagall Act. At the time there were many actions by large banks to try to maximize profits, and in many peoples' minds this new Act serves as a marker of the things to come.\n\nInterestingly none of the reversals had a [direct impact](_URL_0_) on the major components of the financial crisis of the late 2000's. Even so, it serves as a marker of the shift of importance and focus on banking profit maximization.",
" Glass-Steagall made it illegal for certain companies to own other, financial companies. In effect, this meant investment banks (that invest in other businesses) and commercial banks (where you go to save your money) couldn't be owned by the same people. \n\nThe Gramm–Leach–Bliley Act removed this provision. This meant that companies that gambled on other businesses (investment banks) and companies that did home loans and deposit and so forth (commercial banks), could become one institution. It meant that investors could gamble with more money than they could have previously. Bigger rewards for the banks, but a bigger risk that ultimately made the recession worse because all banks were now exposed to investment failures instead of just investment banks."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do we have multiple blood types?
|
[
" In an evolutionary sense, the answer is \"because there was never really a reason not to, and it just sort of happened\". Blood transfusions are an extremely recent thing and before that we never really had a vested interest in everyone having a compatible blood type.\n\nBut you're probably interested in what causes it to happen. There are a bunch of proteins on the surface of each cell, including blood cells. These proteins are differently coded as the person's genetics would dictate. There are, furthermore, antibodies produced throughout the body that check these proteins, see if they're the type of protein that the body regularly produces, and if the protein is unrecognized, they may destroy the cell.\n\nThere are a *bunch* of blood typing systems, but the two most important are ABO and Rhesus factor. \n\n----\n\nYour ABO gene, for which you have two pairs, may present as the following genotypes, with phenotypes in parentheses:\n\n* AA (A proteins presenting)\n* AO (A proteins presenting)\n* AB (A, B proteins presenting)\n* BO (B proteins presenting)\n* BB (B proteins presenting)\n* OO (No relevant proteins)\n* Extremely rare types such as _URL_0_\n\nThis is relevant primarily in transfusions because if you give someone a blood transfusion, the received blood MUST not be of a type that presents proteins other than those presented by the recipient's blood. So excluding extremely rare types, OO is always safe to be received, while BO can be received by people with BB, BO, or AB type blood. AB is ONLY safe to receive by AB people. You can maybe figure out the rest.\n\n----\n\nThere is another blood typing system that is a little more obscure: that is the Rhesus factor. It's simpler: you're generally either:\n\n* Rhesus positive (protein presenting)\n* Rhesus negative\n\nThis is mostly relevant in pregnancy, because when a Rh- woman has a child through an Rh+ man, her immune system has a tendency to modulate a little bit in such a way that subsequent pregnancies from the man may actually invoke an immune attack on the fetus: this is known as _URL_1_\n\nAgain there are a number of blood typing systems but these are the most relevant, so most people summarize their blood transfusion with a reference to each: I for example am O negative (which is the most common blood type in the world)."
] |
[
" Copying a previous response I gave to this question:\n\nThink of blood type as a sort of evolutionary side-effect; there are few clear advantages to having different types, it's mostly just that separate populations sort of evolved them separately.\n\nEverything I'm about to say is an oversimplification, but this is ELI5 so I think that's the point.\n\nFundamentally blood type is used to classify what kinds of \"immune markers\" your blood has. Someone who has type A blood has \"A\" immune markers in their blood; their body knows not to attack anything with the \"A\" marker in it, so you can similarly receive blood donations as long as the only markers they have are type \"A\".\nType B blood is just like A, except that it's a different marker; if a person with type B blood gets transfused with type A blood, their body will see the A immune markers and think the blood is foreign, triggering an immune response (which is pretty severe and can kill you). As such, someone with type B blood can only recieve blood if it doesn't have type A markers in it.\n\nType O blood effectively has no markers. This is great for donation, because it means that anyone can get type O blood without their body rejecting it. The problem is that type O people have to get blood with no immune markers, as both A and B will trigger an immune response. Type O blood is referred to as the \"universal donor\", as anyone can recieve it.\n\nType AB blood is blood with both A and B markers; as such, no marker type triggers an immune response and they can effectively receive blood from anyone (hence the title \"Universal Recipient\"). This also means, however, that only someone who is type AB can receive AB blood, as it will trigger immune responses in everyone else.\n\nHope this helps!",
" Blood types are way more complicated than most people realize.\n\nBlood types are basically a way to describe what proteins are present on the surface of your red blood cells. Somebody with type A blood cells has a type A protein on their RBCs (Red Blood Cells), a person with type B blood has protein B on their RBCs, and a person with type AB has both and a person with type O blood has neither.\n\nBut the ABO system is not the only blood type. There are also the Rh proteins (Which are usually designated with either positive or negative after your ABO typing), and the Rh typing actually describes the activity of 50 different proteins that are considered as a whole in determining if you are Rh+ or Rh-.\n\nThe H/h system determines your ability to express your ABO type. If you lack the H antigen you are designated as blood type Bombay, and are neither A/B/AB/O. Extremely rare.\n\nSe/se typing determines whether your blood proteins are found only on the surface of your RBCs, or also body fluids such as saliva. It also acts (when found with H) to convert another blood group, Lewis, from Lewis-type-A to Lewis-Type-B, determining which is adsorbed onto the RBC surface....\n\nAnd so on and so on. There are over 30 different blood groups (covering hundreds of different proteins) in addition to ABO, although not all of them are as critical in transfusion. Some groups will actually change over time, some are altered by pregnancy, others by exposure to transfused blood, and this isn't even considering the antibody systems directed against foreign blood types.\n\nSo, humans have different blood groups because blood groups are complex emergent systems influenced by the interaction of hundreds of protein systems in our blood and endothelial cells. Certainly, new blood groups are possible, as mutation could alter any of these proteins in any number of ways.\n\ne: Thanks for gold reddit!"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why can temperatures get crazy high(Planck temperature) but not as crazy low(−273.15°C, Absolute Zero)?
|
[
" Whoa, took me some time to understand that question.\n\nTemperature is just jittering of particles. Absolute Zero means no movement. Thats why you can't go any lower. On the other hand, you can go as high as you want by throwing in more energy to make stuff more jittery."
] |
[
" The [Planck temperature](_URL_0_) is the temperature where our current physical theory breaks down, so... That's probably the closest we know of as \"absolute hot\"",
" > A negative kelvin temperature indicates that particles at high energies outnumber those at low energies.\n\nIt just means this.\n\nThis article is about a very, very technical use of the word \"temperature\", not about temperature in the usual sense.\n\nHere are the parts of the article that summarize it best:\n\n > Physicist Ulrich Schneider at the Ludwig Maximilians University of Munich set out to do something unusual: He wanted to cajole the particles within a substance to be confined to a very high amount of energy. In other words, instead of having the particles start at a minimum energy (corresponding to absolute zero) and spreading out toward higher energies, he wanted to start at a maximum energy and spread toward lower energies. By definition, such a substance would have a negative kelvin temperature.\n\n > This temperature is technically not below absolute zero, because negative on the kelvin scale (unlike that on the Fahrenheit or Celsius scale) is a construct that simply indicates something about the energy state of the particles involved. In fact, the new creation is extremely hot because of the high energies of the particles. Heat travels from hot to cold, Schneider says, and heat will always flow away from this gas. “It’s actually hotter than everything we know,” he says.\n\nOnce again, this is about a kind of technical quantum mechanics thing, so it's hard to explain exactly what they mean in terms of every day activities."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do we find comfort in eating, well, comfort food?
|
[
" I believe it's connected to the endorphin release when you eat food, particularly high-sugar/fat content food. Endorphins make you happy, roughly speaking. The body is geared to reward behaviour that leads to consumption of sugary/fatty foods because pre-civilisation humans needed as much of those two things as they could get."
] |
[
" I really like food. Like, really really REALLY like food. Eating delicious food makes me happy, at least for a while. Normally, I try to maintain a decent diet, avoid overeating, etc. When I'm upset or stressed or sad, the first thing to go is my self control about what I eat. Since eating good food makes me feel better, when I don't feel good, I eat. \n\nSome people have different solutions, including alcohol, drugs, or sex. Other people have healthier solutions, like exercise, volunteer work, creative work, etc. \n\nWhat we're basically looking for is a burst of dopamine to make us feel good.",
" emotionally, stress and sadness gives a feeling of physical emptiness. happiness and food gives feelings of contentment and physical fullness. it's a pretty obvious link really, you're trying to be full and content instead of hollow and unhappy. it's called comfort or emotional eating, and it's very common."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
When and how did people start wearing bikinis at the beach?
|
[
" [Ancient Rome.](_URL_0_) Of course, it went out of fashion for a while there, before coming back with a vengeance in the 1960s.\n\nBut standards for what was considered \"appropriate\" swimwear for women have changed back and forth over the years as cultural mores (and morals) changed. It's not easy to give a compelling description for *why* those changes came about in an answer suitable for ELI5. Suffice it to say that they do. The 1960s saw the loosening of cultural standards in a wide variety of areas, including what were considered acceptable standards for women's attire, on and off the beach.",
" The bikini was designed in 1946 by Louis Réard. He named it after the Bikini Atoll, where the USA was testing hydrogen bombs - the connection being that the bikini was going to blow up like a bomb in fashion.\n\nBy the 1930s, people were wearing more revealing swimsuits, and women had started wearing two piece swimsuits (although they were more like shorts and a tank top.) Réard took this trend one step further with the creation of the bikini."
] |
[
" that is the exact reason. i think it was the london olympics, they said it was too cold for the women to wear bikinis for the volleyball games, now this may have been completely true, but the women were very unhappy about it",
" Hey it's the same for guys. We wear only shorts at the beach. But would you wear only shorts at your work? Or the library? You'd likely be embarrassed because you're sticking out like a sore thumb.\n\nPlus when a woman puts on a bikini, she is willingly prepared to be seen in a bikini. Her mind is set and prepared. However if she's at her job and a button pops loose suddenly revealing her bra, she's not prepared for it. And it's probably embarrassing!"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Supply Shocks
|
[
" **Simple**!\n\n[Take this diagram](_URL_0_);\nAggregate Supply (AS1) is the MAXIMUM possible supply in an economy. A negative supply shock would be, for example, an oil field exploding or something, or a war in an oil producing country. Everyone gets scared and supply rapidly shifts ***left*** to AS2. As **Aggregate demand** still stays the same, the price moves from P1 to P2, a much much higher price. \n\n\nThe same is true for **positive** supply shock. When they happen they could be anything from an advancement in technology, to a new discovery of a massive deposit of a raw material and increases supply suddenly and rapidly, moving the supply curve to the right, and as AD stays the same, the price drops significantly. Hope this helps, if not, please clarify.\n\n\nIn leymans terms, with a positive supply shock, there is more of something to go around, so the price drops. \nIn a negative supply shock, there is less of something, so price increases.\n\nA common supply shock nowadays is the weather affecting crop output."
] |
[
" You get shocks from those items because they're (mainly) made of metal. Since metal is a fantastic conductor, the static electricity generated in your body by carpets, beds, blankets, etc. rushes out of your body and into the object, creating the tiny zap you feel.",
" Supply side economics is a fairly broad term to describe factors that form the supply side of the supply and demand economic model. That is; it only concerns itself with issues that face suppliers (firms and industries). Typically these issues mainly deal with resource allocations and management and the pressures and cost associated with these concepts."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do our muscles shake violently when you lift weights or something very heavy?
|
[
" Your body uses charged atoms of some elements, also known as mineral ions or more popularly, electrolytes, to send the signal for your muscles to contract or relax, and your muscles use other mineral ions to actually contract and relax. Heavy use of the muscle can temporarilly use up the ions in those muscles cells, resulting in a loss of muscle control because there is no longer a sufficient supply of the ions to clearly signal and/or maintain steady contraction. Regular training helps reduce shaking as your body will adapt. When my muscles fatigue they don't shake, the weight just stops going up. Staying hydrated with enough electrolytes will also help, so drink your Brawndo."
] |
[
" In my understanding, it's because your muscle fibres are literally breaking after heavy use. They're replaced with stronger fibres, but that takes a couple of days. This is why you get physically stronger and can lift more weight.",
" I'm not sure about the chemical process, but when you lift heavy weights, you actually cause microscopic tears in the muscle fibers. When the body repairs those tears, it makes them bigger and stronger so it hopefully won't tear again (which is why you have to lift heavier weights to keep getting bigger)."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What do you do with your invention idea?
|
[
" Really depends on what you've invented/what your idea is.\n\nIf it's a mass-market thing, or something that can be quickly duplicated by competitors and you haven't got the capacity to produce and distribute widely yourself, you might want to consider licensing. Find a company doing something similar or related and pitch it to them in exchange for a license fee.\n\nIf you're going it alone, then a business plan, marketing plan, etc are a must. How much money you need depends on what your startup and operating costs will be. Whether you'll need patents depends on the idea too. \n\nBefore you even start going through the process of developing a plan though, it's worth your time to discuss it with some people first. It might seem like a great idea, but we aren't always the first ones to see major flaws in our plans. Most importantly, try to avoid using family or close friends for this, as they're the least likely to be completely honest if an idea really sucks."
] |
[
" Well, you probably would just teleport around the world and not give a crap about the science...\n\n...But for science, you'd write a paper where you in your own words describe the general idea behind your device, how it functions, and whatever you did to make sure it actually works. If you built a prototype, there's very little beside saying \"I built this, tested it like this, and this is what happened\". If you didn't built prototype, then you'd probably want to demonstrate in practice the principle that allows you to build teleport or whatever. If you really can't demonstrate any concrete results, then you're gonna have to describe the math that allows this teleport. The idea basically is, if you found something new that others did not know before, you describe what this new thing is, and then you describe why you believe this new thing to be true.\n\nThis paper you'd submit to some scientific journal.\n\nMost journals then have step where after submitting your initial draft, they assign two(or one) scientist of that field to review your paper if it makes sense, and if it otherwise passes the requirements to be published in that journal. It's not uncommon for reviewer to make requests about clarifications or other error fixing before submission is accepted, but if they deem that the paper is plagiarized, nonsensical gibberish, wrong in some fundamental way or that the study itself doesn't have enough significance to warrant publishing, then it may just as well be rejected outright.\n\nIf you invented teleportation, you'd probably be rushed through the process as long as you can write half-intelligible sentences and your method actually works as described, but still, good presentation never hurt anyone, saves everyone a headache.\n\nAfter that, some time passes before it's printed and the journal goes to circulation. After that happens, the world reads your description of your idea, and start trying to figure out if they can replicate the results and if your thing makes sense. If it does, then everyone goes on to see if they can use this result to do something cool, like notice ways to improve your teleport machine.\n\nThat's more or less it.",
" If you invent something and patent it, you can prevent other people from selling their own versions of your invention. You don't get money directly from the patent. You can however license other companies to produce your patented thing for some sort of fee paid to you, or whatever other details your contract might specify.\n\nOf course, you can also sell your patent rights, giving the buyer the same rights mentioned above."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do people click the receiver on a telephone when they lose a call? Wouldn't that hang up on the other person?
|
[
" Quickly pressing and releasing the \"hang up\" button (properly named the \"switchhook\") is called a [hook flash](_URL_1_). In very old telephone systems where an operator would manually connect your call for you, picking up the phone would cause an indicator light to come on on the telephone [switchboard](_URL_0_) that was being monitored by the operator. A hook-flash would cause the light associated with your telephone line to flash (hence the name, \"hook-flash\"), which was intended to attract the attention of the operator so you could ask them about the disconnected call.\n\nIn more modern, automated telephone systems, a hook-flash is sometimes used to switch between callers if you have call-waiting enabled."
] |
[
" I saw this in a WTF Fun Fact a while ago. People pace when they are on the phone because they don't have visual feedback to go along with the other person's speech. They body reacts to this lack of feedback by moving around",
" Think of it this way.\n\nAlmost everybody has a mobile phone these days. How is it that you never call and get put through to the wrong person?\n\nIt's because a phone number is 100% unique. Cars work the same way - each key is programmed to a very unique serial, and only works for that one car."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How do they make razor blades so sharp?
|
[
" Razor blades are also sharpened in a long strip, often endlessly from a long reel of stock, before being cut into blades. The steel is also an alloy very different to that used for a knife. A knife made from razor blade steel would be uselessly brittle.",
" A razor blade is passed through several sets of grinding wheels to produce a sharp edge. Each set grinds the blade edge more than the previous one until it's very sharp. The cutting edge is then usually polished by rotating leather wheels. Sometime a coating is applied to protect the sharp edge. Done."
] |
[
" It gives the blade a point to drive forward, if that makes sense. Imagine you have a big juicy steak in front of you. You grab your fork and knife and get ready to cut a bite. Your knife is perfectly straight from the handle to the tip. As you try to cut your steak, the tip of the knife keeps stabbing at the meat and it's taking quite a lot of energy to get through the meat. \n\nSo you set down that knife and pick up a slightly curved one. Instead of the straight downward pressure you used before, you can now start with a higher angle and drive the curved edge through the steak with ease. \n\nThe same goes for swords. You're in a war and you're running at your enemy with a sword. It's got a straight sharp blade. You swing it at him and you land a nice deep cut, but your blade got stuck. You struggle to get it out while your enemy swings at you. Now imagine the same scenario with a curved blade like a scimitar. You swing and hit your enemy; although you may not have landed quite as deep of a blow, the curved blade had less of a chance to get stuck.",
" Because each blade individually \"chops\" through the air, parting it, and creating lift. They do this at all time, and you perceive it every time one comes close to you as a louder chop due to proximity of the noise."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Generic Universal RolePlaying System (GURPS)
|
[
" Whenever you play a role playing game, there are rules and a system that determines what you can do and how you can do it. Things like what order turns go in (if there even are set turns), how to handle fighting, damage, character creation, money, etc. You also have a universe that the game is set in, which defines things like maps and locations, character species/races, the currency and languages of the world, and any history of the world that is universal to all games set in that universe. For each game, you also have a campaign or scenario, which takes those rules and that universe, and adds a story to it that you can play. Most of the time, all three of these are packaged together, or at least the first two with scenarios being designed to work together with the first two.\n\nDungeons and Dragons defines rules and a universe, and the campaigns and scenarios you get expect that you will play them in the DnD universe with DnD rules.\n\nAll of that is great, but what if you like to play your own games? You can take rules from DnD and set it in another universe, but often the rules for one game are specific enough to that universe that it's hard to use them in say, the Lord of the Rings universe, or the Harry Potter universe, either because they fail to cover important features of that universe, or they directly contradict basic aspects of that universe (usually crops up when you talk about how magic works, which varies wildly). Or maybe you just don't like something about the rules. I find that DnD 4e overcomplicates combat while ignoring everything that happens inbetween combat situations. \n\nGURPS is basically a rule set that is designed to be easily modifiable to work in any universe. Rather than being tied to one specific one, the rules have sections you can add and remove at will to make them work in whatever universe you like. That way you don't have to write your own rules, which can be tedious and have poor results (what happens if your PC's get to level 20 after months of play and the game has become ridiculously unbalanced?) You can take the GURPS rules, paste them onto a universe of your choice, and come up with a scenario and you are good to go."
] |
[
" well, assuming you've already checked local gaming groups and not had luck, you can try online. roll20 is a site for doing ttrpg online. there's others too, but it's more or less the gold standard.\n\nif you check out /r/rpg and /r/dungeonsanddragons, plus /r/dnd, you'll find loads of useful links in the sidebar, and a quick search for pathfinder should give useful info. there may even be a pathfinder specific sub, I'm sure there is, but I've never played it so I haven't looked\n\nfor local gaming you have to get lucky if there isn't a shop that runs a game. I've seen ads on Craigslist for gaming groups though. \n\nbut honestly? the absolute best fun you can have with any system (d & d, pathfinder or other d20 offshoots) is right get a group going with friends or family. that's probably going to mean you play DM, but that's loads of fun itself.\n\nI think as far as getting a grasp of the rules, you'll want to just roll up a test character. try it out with pre made stuff and get a feel for it. iirc pathfinder is based off of d & d 3.5, which can be a bit thick to get at first. but it's way simpler than the original d & d rules lol.\n\nbut the basics should be the same. you get the character sheet. there's six base stats, strength dexterity intelligence wisdom constitution and charisma. each represents the abilities your character has as a base. there's different ways to generate the numbers (I prefer rolling dice over point buy).\n\nonce those are done, you look at the tables for the adjustments.\n\nthe race and class you either pick before rolling and tailor the stats to them, or take the stats and pick ones that fit them best. beyond that, most of what you'll need will come from charts in the book/s.\n\ncombat tends to be fairly simple. roll a d20, compare the roll to the difficulty represented by armor class, and either do damage or not. there's extra rules for magic and special attacks, but the basics remain. there's always a d20 check against a difficulty. \n\nif you have specific questions, I'll try to answer them, but I'll have to find the pathfinder books to be certain of their system. it's close to d & d, but has some key differences",
" Okay. In the Dungeons and Dragons tabletop roleplaying games, the characters that players portray in the game (fantasy adventurers, Elves and Dwarves and the such) are divided into \"Alignments\" that describe their personality. There's two types of alignments. \n\nLawful, Neutral and Chaotic - Describe the character's approach to law and order. A lawful character follows the rules, a Chaotic character rejects the rules, and Neutral characters are somewhere in the middle. \n\n\nGood, Neutral and Evil - A Good character will help others at their own expense. An Evil character will hurt others for their own benefit. A Neutral character is somewhere in between. \n\n\nBy combining those two, you get an alignment that describes how your character responds to the world, giving a baseline for what sort of decisions your character will make. A lawful good character will help others while following the law, while a chaotic good character will break the law if they need to in order to help others. A lawful evil villain will be a dictator, a tyrant who punishes those who disobeys, while a chaotic evil villain will break promises they make if it lets them hurt people."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why are American movies released in almost all the world but movies from say Japan or Europe almost never get a wide release in the US?
|
[
" Did some googling, so take this with a grain of salt, I suppose. \n\nAccording [Ms. Deborah Swallow](_URL_0_), American media is dominant largely due to our (comparatively) strong economy and our use of the English language. Since the English language is still widely spoken across the world, films don't need to be translated to be shown in many countries. In particular, the big-budget action movies popular in the US rely more on special effects and action, and don't require a lot of specialized knowledge in cultural or historical background. This kind of explains why the recent influx of superhero movies has been fairly widespread, for example--with a few exceptions, most of the superheroes are fairly self-contained in their movie universe.\n\nIf anybody else has some specialized knowledge on this and wants to chime in, feel free."
] |
[
" they sometimes release it earlier in other countries to predict how the movie will fare in its country of origin. for example, I remember awhile back that fast and furious 5 was released early in Australia and it dominated a competing movie there, so it gave the production company a sense of what might happen in the US (or any other country a movie may originate in)",
" A lot of American films are released in other countries first to try to gain attention and stir up bigger sales in the Foreign markets. Also not all of them are dubbed, many are just adding subs in the native language.\n\nSee link for alt reasons:\n_URL_0_"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
If getting to the moon was such a momentous occasion, why hasn't the US/NASA (or any other country) sent a manned mission there in 40 years?
|
[
" The main drive to get people on the moon was because of the Space Race with the Soviet Union during the Cold War. They had beaten the US in two major space-travel landmarks before us; Sputnik (first satellite) and Yuri Gagarin (first man in space). Getting men on the moon was a momentous occasion because we \"beat\" Russia. But there wasn't actually all that much on the moon or that we learned from it, even in several follow-up manned missions."
] |
[
" I think the US sent a man to the moon more for national pride than for any practical purpose. JFK declared America's intent to complete this mission in order to send a message to the Soviets and the world that the US was a superior nation. \n\nToday, it's less about pride and more about science. It makes no sense to send manned flights, because unmanned flights are cheaper and more versatile, and can do things that humans can't, like stay there for long periods without food.",
" Largely, because going to the moon was a publicity stunt, an attempt to prove that the US was better than the USSR. Once that goal was achieved, there was no particular reason to go back. It's far easier and cheaper and (about 95% as) effective to just send robots. \n\nA similar thing will likely happen with Mars. If the Chinese (for example) make a serious attempt to go, the odds are good the Americans will make some attempt to beat them to it. And, then, once having been there, that'll be it, not necessarily forever, but for a long time. \n\nOn /r/futurology/, they often talk about how living in space is inevitable or some sort of an ideal future. This is not a likely scenario. Space is too inhospitable. At best, we'll have an Antarctica thing going on, with a small number of researchers and their support crew living in space for various amounts of time, with the vast, vast, majority of people living their whole lives on Earth."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
The inclusion of "under God" in the Pledge of Allegiance during 1954.
|
[
" one of the main points of propaganda against the soviet union was that the soviet union was atheist and godless, while the US was strong under the protection and guidence of god. \n\nThe pledge of allegiance was written by a baptist flag salesman to increase sales anyways."
] |
[
" Before the change of the Pledge in the 1950s as a result of the Communist hysteria, you would have recited a different version. This page from a 1936 high school autograph book. _URL_0_",
" because the cold war and American's hate \"communism\" (using air quotes there) and everything we associated with the soviets. to the point where the words \"under god\" where added to the pledge of allegiance because the soviets where seen as atheist."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
If alternative energy sources (wind, sun, geothermal, maybe nuclear) are a economic threat against fossil fuels (oil, coal), couldn't fossil businesses make a (gradual) transition to these sources?
|
[
" They are not, and they are not likely to be for a very VERY long time. Reddit is an extremely biased community, that presents a 1% reduction in the costs of production of solar panels as a fucking panacea to the world energy needs. This makes one wonder, why aren't we all using solar panels and wind energy yet? With the recent violent falls in the costs of commodities, including oil and gas, the \"green\" energy sources have become even less competitive. The Brent price is likely to never hit a $100/barrel price again, so it is likely that investments in green energy are going to fall even further. This makes our shift to green energy even less likely any time soon (and not too soon). The idea of economic viability of switching to green energy is pure and utter bullshit, unless we start to incorporate the negative externalities in the cost of conventional energy sources. And we are not likely to do that, because that could reduce the standards of living of humanity by a factor of 1.5."
] |
[
" Because climate change is caused by the burning of fossil fuels, coal, oil, and natural gas.\n\nWithout these fuels, our civilization would collapse. We don't want this to happen, so we can't ban them.\n\nThe only currently practical replacement right now would be to build large numbers of nuclear plants, enough to get most of our electricity this way, and switch all vehicles to electric.\n\nNuclear power is highly unpopular, and the people who are the most concerned about global warming tend to be the same people who are the most against nuclear power.\n\nEnvironmentalists would like to replace fossil fuels with solar and wind power, but there are serious drawbacks with each that make it impossible to actually run an electric grid solely off them. The sun doesn't shine during the night, and the wind doesn't blow all the time.",
" Well first of all, our energy (as in, electricity production) isn't really based on oil. It's based on Coal and Nuclear and Natural Gas.\n\nNext, any switch to pure renewable simply could not possibly be fast. Unless you got some magical material which was MUCH more efficient than solar and extremely cheap and ALSO supremely amazing batteries that let them work consistently.\n\nBasically you're suggesting \"if we did a move which would only make sense if it were cheap enough\" than people would go elsewhere because it was cheaper. It just doesn't seem to make much sense, you're looking at this in a far too simplistic way, and you're looking at a policy that no one is suggesting (immediate banning of coal/nuclear/natural gas/coal) as if it's something that's routinely suggested."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do many think socialism is costly and unattainable?
|
[
" Because most people view socialism as taking money away from people who work hard and deserve it, and give it to people who don't work hard, and don't deserve it."
] |
[
" Modern socialist countries come close. Really, it's a matter of technology and infrastructure - Communism is practically impossible because of the massive administrative costs, bureaucracy, and logistics - all of which are aided significantly by modern information technology, which is why socialism is working, because it's sort of a compromise between private ownership/business versus government ownership/business.\nIf we ever get to Star Trek-level technology with fusion power, replicators, and teleportation, getting food to the needy will be practically free and effortless, which is why in Star Trek no one starves. The only reason people starve now is that it costs money and takes time to move food (plus the people who have it have to be willing to share).",
" Because many Americans have no clue what socialism is and equate it with communism. Anything that implies any involvement with government aiding anyone that they find \"unworthy\" is denounced as a waste of resources. We have half the electorate wanting government to aid all of us and the other half not wanting government to help anyone they don't like. Essentially it's a sad hold over of our racist past."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do my feet smell so bad?
|
[
" The cause of foot odor is bacteria. \n\nThe reason why foot odor is so bad and not common with other parts of your body, is that the bacteria growing in your shoes or on your feet are doing so in moist and air tight environments. Your feet get moist from sweat, so bacteria are able to thrive in that environment. Wearing nylon or cotton socks makes it worse since it increases the moisture captured and also make your feet warmer.\n\nA cheap fix is to use baking soda. Also, rubbing your feet twice a day with rubbing alcohol will help alleviate the odor.\n\nYou can also try to buy shoes that are more \"breathable\" which allows moisture to escape your shoes. Wearing wool socks may help too (wool doesn't absorb water easily and is more breathable)."
] |
[
" It has to do with the anatomy of your nose. There are scent receptors in your nose that can get saturated when being exposed to the same smell over and over again through a period of time. Its essentially the same thing that happens when you first spray perfume on your self, you can sense it for a while but then you don't smell it anymore but others can smell it on you. Same with BO only very unpleasant. Also the reason why some people reek of perfume, they keep reapplying when they really don't have to.",
" Foot odor is often caused by a fungus growing on your feet (because its often warm, damp and dark in your socks and shoes - an ideal environment for it), whereas other \"normal\" body odors are caused by bacteria reacting with your skin oils and sweat. \nDifferent smells for different organisms and their biological processes. Try to keep everything dry to avoid them (deodorant, foot powder, etc.)"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How to use IRC
|
[
" 1.)Download mIRC.\n\n1b.) Crack or buy it, up to you. \n\n2.) If you know what server you want to connect to, type /server -m _URL_0_, the -m is a flag that opens it in a new window.\n\n3.) After you are connected, type /list for a list of channels to join, and if you find one, or know what you want to join, type /join #xxxx.\n\n4.) Follow channel rules regarded getting files and chatting. \n\nI write this while completely wasted. Feel free to correct me."
] |
[
" The way the normal Internet works is like this:\n\nWhen you type _URL_1_ into your browser, you computer literally asks the nearest computer it can find which computer hold the file _URL_0_. That message bounces around from computer to computer until it finds the computer that has _URL_0_ on it, which then bounces its way back to your computer. With the right tool, anyone can follow this path your computer makes, and figure out where any computer is in the chain.\n\nWhat tor does is stick an untraceable cloud in the middle of that chain. A message leaves your computer to the next, but then enters the tor network, which uses a lot of tools to make sure that no one can trace the message back to your computer. Instead, the farthest back they can trace is the edge of the tor cloud.",
" Take out a large enough amount of the core interconnect points such as\n\n_URL_2_\n\n_URL_1_\n\n_URL_0_\n\nAnd it would render a lot of the net functionally inactive for a period of time."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How does a mechanical keyboard improve typing speed?
|
[
" Tactile feedback is improved, resulting in less missed keys, AND key actuation rate (the speed at which the keys move up and down) is greatly improved, resulting in a more fluid key movement, which can contribute quite a bit to speed."
] |
[
" There's a sensor that detected when he twiches that muscle. That directs the computer towards a control like a single key on your keyboard. Except he types really really really slow. Like 1 word a minute.",
" The reason for the QWERTY keyboard we use today goes back to the first mechanical typewriters in the 1860's.\n\nAt first, typewriter keyboards were arranged in alphabetical order, but there were problems--specifically, when quickly typing two letters that were next to each other on the keyboard, the mechanical arms that did the printing would jam.\n\nSeveral different keyboard configurations were tried in an attempt to avoid jamming, including some designed to force typists to slow down (which pretty much defeats the purpose of typing in the first place)\n\nThe QWERTY keyboard was designed to separate the most commonly used letters from each other, to help keep them from jamming. As it turns out, the QWERTY keyboard did its job, yet still allowed speed typing--my greats grandmother could type 120 wpm on a mechanical typewriter before she died.\n\nOther styles were developed, but they didn't catch on for one reason or another, although at least one is still seen in use occasionally: the Dvorak keyboard, invented by a man named Dvorak, is still occasionally used for speed typing."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How do they make weed killer that they can spray on grass and plants that only kill weeds without hurting the grass or plants?
|
[
" For killing weeds in your lawn, the most common herbicide is 2,4-D. Most weeds are broadleaf plants which means the growing part of the leaf is exposed (think a flat leaf growing wider). Grasses grow from the root. 2,4-D mimics a growth hormone and when it is sprayed on growing leaves, it makes broadleaf plants grow so fast that they can’t keep up, and they eventually starve to death. The grass root is underground so the growing part of the grass plant is protected from contact with the herbicide.",
" In the context of grass and the RoundUp products that you can buy for broadleaf weeds, it has to do with the herbicide being specific for dicot plants (weeds) instead of the monocot plants (grass) like other people have mentioned. \n\nHowever, in commercial farming herbicide is often applied to a field of crops as a mixture with a chemical called a safener. Safeners are meant to keep the crop \"safe\", hence the name, preventing it from herbicide injury. However, an intriguing aspect of this field of study is that the molecular mechanism of safeners is not fully understood. The one thing that we do know is that safeners cause the overproduction of an enzyme called glutathione-S-transferase (GST) that detoxifies the herbicide by breaking the molecule into smaller parts. The signaling pathway that safeners use, however, is the big mystery. \n\nSource: I am a research assistant in a Crop Sciences lab and this is our main focus"
] |
[
" There is no proof of negative health effects. One reason a lot of people dislike them is that they are created by Monsanto which has engineered their seeds to be resistant to the best selling weed killer Round Up. As you might have guessed, Round Up is also created by Monsanto. They also require farmers to purchase new seeds from them every year instead of generating their own.",
" Weedkiller that preserves grass tries to avoid using chemicals that harm grass. For example, imagine there are lots of pups and kittens, and you want to (gasp!) kill all the pups. Try chocolate. That kills dogs but not cats (AFAIK, correct me if I'm wrong, you get the point though). Why should different types of plants have 100% same mechanisms? Some chemicals hurt some plants, and not other plants.\n\nA weedkiller formulated against poison ivy might not be useful against a weed in your grass; it may even kill your grass as well. ETC."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do they do court room sketches? Why can't they just take a photo?
|
[
" In the UK, cameras aren't allowed in courtrooms, I remember visiting a museum once that was part of a courtroom and they said if we took a picture we'd be arrested. This means that artists have to draw the suspects in court instead of people just taking pictures.\n\nThey do take pictures of people walking in and out of the building, but they also like to get the emotions into the drawings during the trial too.",
" In many jurisdictions, cameras are not allowed in courtroom in order to prevent distractions and preserve privacy. This requires news media to rely on sketch artists for illustrations of the proceedings."
] |
[
" Because in many/most cases, camera's are not allowed in the courtroom. This is to prevent distractions and privacy violations.",
" Some courtrooms don't allow cameras or videos inside. So the sketch artists provide alternate images of the main players in the cases for the media."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
When I have a bad cold and lose my voice, why can I still whisper and it sound like a normal whisper?
|
[
" When you whisper, you're not moving your vocal cords at all. \"Losing your voice\" involves irritation of your vocal cords. But if you're not moving them, then they have no impact on the sound of your voice.",
" Because whispering is half of speaking. \n\nYour vocal chords generate a tone, which your mouth then shapes and filters into various sounds. But you can replace the tone with \"loud breathing\" - i.e. noise - and get a very similar effect to speech. This is what we call whispering. \n\nSo when you're sick, the part of you that sounds different is the tone-generating part. Your mouth doesn't stop being able to filter sounds, you just have a problem with the input part. But when you whisper, no tone is involved, so you sound the same as when you're healthy. \n\nSource: former sound engineer"
] |
[
" Your voice mostly comes from your voice box (or larynx). Talking or shouting too much, will scar or damage the tissue in your voice box, causing it to inflame, or swell up. Because of that, your vocal cords won't vibrate properly, giving you a harsh sounding voice, or none at all.\n\n\nFurther reading: The condition of losing your voice is called [Laryngitis](_URL_0_)",
" Part of the mechanics of talking involves breathing. The normal sound of your voice involves talking and breathing through nose and mouth. When you're congested, the nasal airways are blocked and the movement of air that contributes to your normal voice is changed. So, you sound like the telephone operator."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Since light travels at a speed which is a function of distance over time, would it be dark if you were able to freeze time?
|
[
" This is a tricky question to answer, because you can't freeze time and if you can't do something you can't answer what-ifs about it. This is definitely going to go above what a five-year-old could understand.\n\nHowever, I'll try anyway. What we perceive as time is us noticing the spreading out of matter into the space the big bang created. So, if we were to freeze time, what we really would be doing is freezing all matter and energy everywhere, meaning nothing is moving. Accordingly, it seems reasonable that everything would be dark. \n\nBut wait a minute! If we froze everything at once, we would be freezing ourselves, and that means the chemical interactions that cause us to see stuff and perceive stuff would also be frozen. So you wouldn't see or experience anything.\n\nUnfortunately, I think this question is kind of non-sense. What I mean by that is it seems like a question that makes sense, but the more you dig in to it, you realize the premise behind the question doesn't make sense. Nothing wrong with that, as there are millions of questions and phrases like this. My favorite is this: \"Colorless green ideas sleep furiously.\" Grammatically, this sentence makes perfect sense. Semantically, it is meaningless."
] |
[
" Because essentially a way to explain the speed of light being a fundemental speed limit in the universe is time, time moves at the speed of light and if anything is traveling at the speed of light then it is frozen in time. Once something is moving at the speed of light then no force exerted by it would affect it, as it would take an infinite amount of time as well as energy to do so",
" The speed of light in a vacuum is a constant no matter what frame of referance you use. This is the reason time slows down when you start going close to the speed of light. Its complicated math but simply if you are going 1/2 the speed of light and shine a torch forward you see that photon shoot off forward at the speed of light, but for somone stationary they too see it travel at the speed of light not speed of light + the 1/2 speed of light your traveling at.\n\nNow when light moves through space it is affected by gravity the same as everything else. If you had an infinity flat \"Earth\" and shot a photon horizontally it would fall at 9.81m/s^2 and hit the ground\n\nThis is where the explination gets tricky as you have to try and visualize space time as dimensional. Which is hard. But if you have seen these images of a flat \"space-time\" grid with a planet plonked on there bending the space-time grid down and distorting it with its gravity.\n\nNow a photon travels allong the lines of this grid. Without the planet there it takes 1year to travel 1 light year easy.\n\nBut when the grid bends the photon as above follows this bent space-time grid. But the distance is longer due to the planets gravity.\n\n[This is what im trying to describe](_URL_0_)\n\nAn observer in the gravity of the planet the photon will still take 1 year to travel the 1 light year, but to the outside observer due to the curve and the fact light in a vacuum always travels at the same speed, it will take longer. This means light and therefore time must have been slowed by gravity.\n\nIn reality its not actually curved but thats the issue with trying to visualize time as a dimensional thing its hard to describe without a wall of math!\n\nEdit: spelling"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
The reason that giveaways/contests have the phrase 'Purchase not required.' and then have an alternative method of entry (usually mailing in a postcard).
|
[
" Because in most places, if a purchase is required to win the prize, it's a private lottery and therefore illegal. So, they have to provide a way for you to enter the contest without purchasing one of their products -- and as you noted, mailing in a postcard is a common way (or, in the case of an instant win, sending in a SASE)."
] |
[
" they are required to give you a free game piece ticket thingy. read the find print. usually it requires sending a self addressed, stamped envelope to one of their offices somewhere. you can send in for a certain number per day per member of household, if the contest is legal in your state.\n\nso no, technically you don't have to purchase anything, but it's easier to buy a drink and fries than it is to send a bunch of single requests for game tickets.",
" At least in the U.S., giveaways, sweepstakes, and similar contests are regulated like lotteries and other gambling. Making a sweepstakes \"no purchase necessary\" allows the company organizing it to avoid some onerous regulation."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why is superbowl so popular? As per my internet research skills, it is the most watched/biggest money making sporting event across the world.
|
[
" It is the biggest money making event because there are ads every 90 seconds. Compared to something like the World Cup, which has more viewers but nowhere near the amount of commercial time.",
" The Super Bowl isn't the most popular sporting event. Viewers ship for the FIFA Football World Cup finals(AKA Soccer for Americans) has much bigger viewership. When NFL officials say 400 - 1 Billions people watch Super Bowl, they are exaggerating, same as when FIFA officials say over a Billion people watch the World Cup. \n\n\nNFL isn't really popular out side North America, Football is popular almost anywhere in the world.\n\n\nI think you need recheck your Google Data. Personally I have never watched NFL, nor do I know anyone who does, From India BTW. When you say MLS or NBA however, that's a large number. Rugby and Cricket too. But NFL or Baseball, nada, zilch, Zero. Personally I never even understood the rules or I don't find the idea of a team of very large and muscled men violently wrestling each other for a funny shaped ball interesting, I don't swing that way, even though I enjoy UFC."
] |
[
" It might not be as popular as it was 30 years ago but it's still popular enough. I watch it and I have a lot of friends who do too. Between PPV, seats, merch, betting and sponsors there's still a lot of money in the sport. And there are less people to pay than in the NFL or NBA.",
" I think its because NFL as a league is more popular than NHL/NBA in states. So they tend to get more media coverage."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does your voice get hoarse when you're tired/sleep deprived?
|
[
" My guess is that when you're tired, they relax and give you a deeper voice. They could be tired and overworked, making it harder for your voice box to vibrate quickly enough to produce high frequencies. When you wake up, your vocal cords are most likely not stretched and the same thing happens.",
" Your voice can get worn out after a long day, especially if you work a service job, are customer facing, or have to communicate with colleagues frequently throughout the workday. The larynx is what actually vibrates in your throat to create sound, and it works like a vibrating muscle. Like any other muscle, it can get irritated by being overworked. Alternatively, it also has to be warmed up to work at full force. So if you just woke up after a night's sleep or a nap, your larynx is going to need to stretch out and loosen up a bit before you'll have your natural tone back. Hot (not scalding) liquid can help relax your voice a bit, and oddly enough, plain old potato chips help with a hoarse voice too. I think it's something to do with the grease they cook them in, which lubricates your vocal cords and reduces some of the scratchy friction while you speak. This is just a theory though that I've heard from some people who sing professionally."
] |
[
" I feel like the biggest reason is because most of us sleep with our mouths open, which can make the throat feel dry and scratchy even when you aren't sick.",
" During sleep, the vocal cords sit there unused and \"loosen up\" a bit because the muscles have been in a resting state so long. The effect is like loosening the tuning screw on a guitar string, the pitch shifts down a bit."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do women’s periods seemingly sometimes “sync up”?
|
[
" Any regular cycles of different periods (duration, not menstruation)will inevitably synchronize at certain points over time. Think about counting by threes and by fives, they synchronize on numbers divisible by both. 15, 30, 45, etc. This is just how things work."
] |
[
" This doesn't actually happen, though it is a commonly cited myth. Multiples studies have shown that there isn't much truth to the \"menstrual sync\" hypothesis, though it can *seem* that way. In any group of adult women, chances are that 1/4 of them will be bleeding at any given time. If they're living in close proximity enough to notice each other's cycles, it's easy to notice overlap with each other and it can easily seem like you are moving in some sort of synchronized fashion. \n\nBut you don't ever get a case where all the women have moved to be on the same cycle, like they're jumping rope together. That just doesn't happen.",
" That doesn’t actually happen. Women’s cycles mostly fluctuate based on the stress placed on their bodies from what I’ve seen.\n\nSource: I’m a woman who has had instances of amenorrhea (lack of a period for a certain amount of time) due to stress and illnesses."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
why are car keys use different mechanisms (Sliding Pins?) then our normal house keys? What are the advantages/disadvantages?
|
[
" There are many types of mechanisms for household locks as well. The traditional pin style is simply the most common. All operate on the same principle however that the valleys in the keys move something that allows the plug to spin. The choice of style is usually dependent on factors such as durability, level of security, and cost to produce."
] |
[
" For the key itself, sure. It is very simple: the shape of the key, and the key code itself. If you look at the teeth of the key, you will notice a number of bumps. It can have for example 5 positions, so 5 pins. Each pins have a number of heights. For example 6. This mean that the key have 5 pins of 6 possible height, for a theorical 6x6x6x6x6 possibility. Less in practice, as they want to ensure a key that can actually be used, and also fit smoothly in the keyhole. They limit the difference between two position height... Since it is a simple code like 34252 there is a chance to have a key with the same code as someone else.\n\nNow, for the keyfob itself. In theory yes, in practice no. It transmit a code, and that code is unique. The protocol will basically be something like \"manufacturer id, serial number, button pressed, rolling code\". The rolling code is a pseudo random sequence of number that is 'secret' between the transmitter (key) and the receiver (car). It may have over 60000 possibility, and the car will listen only for the next few possibility. This is to avoid the need to resync if the car miss some keypress for some reasons (like when out of range). For the car to accept the code, it have to match the manufacturer, the serial number and the rolling code be within the accepted window of values. Not only that, but it also have to be on the right radio frequency. The possibility that two or more car have the same code is virtually null. \n\n\nI can however foresee a conflict with third party keyfob that may need to lie and say it is made by another compagny as to be recognised by the car. Since they are different manufacturer claiming to be the same, the manufacturer field will be the same, and each one will be doing their own serial number, so it is possible to have a conflict there. However both will not be at the same place in the sequence for the rolling code, which should prevent it from opening the other car,",
" There have been car keys that only had a few hundred different cuts, Same applies to door locks: lower quality locks have less pins and less positions (and are quite tolerant about these). Worst lock I've seen had five pins and three positions each, leading to 243 (3^5) different cuts. In theory, but they rarely use the same position in adjacent pins, so its more like 3x2^4, i.e. 48 different key cuts.\n\nThe lock I use has 15 pins (yep, it is not the usual shape...), 5 with three positions and 10 with four, and without this \"not the same position in adjacent pins\" limitation, so it has about a quarter billion different cuts (and some additional features)."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
cutting off a cat's balls is humane but taking off their claws isn't?
|
[
" I'm not going to specifically comment on the humaneness of either, but you should know that declawing a cat is not the same as cutting your fingernails. It is actually the equivalent of someone ripping out the entire tip of your fingers and toes up to the first knuckle.",
" Taking out their claws removes their ability to defend themselves, climb things, and actually changes the architecture of the foot - doesn't work the same way.\n\n\nRemoving their balls keeps them from going nuts and screwing everything"
] |
[
" I think a lot of people are missing the whole reason it's cruel.. Frankly, 'de-claw' is a misnomer, or rather, it doesn't give you the whole picture. \n\nDeclawing isn't a procedure where they go in and surgically remove the nail/claw, it's a procedure that essentially removes the portion of bone at there forefront of the cat's claw that would be the equivalent of removing the tips of your fingers at the first joint...\n\nIt's frankly sick, please re-evaluate before you put something through that kind of torture. Perhaps another pet might be best for you.",
" Cats' wrists and paws are designed for sweeping and batting motions. This is how they run and catch prey. A lot of animals touch stuff as a means of exploration and identification. Cats just prefer swipes to long presses."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How does the GPA system in US schools work?
|
[
" Some schools do it differently, but most are on a 4.0 scale (5.0 being the highest you can get on a 4.0 scale). In your classes, you get a letter grade: A, B, C, D, & F, those grades equal a GPA number. Now, many high schools, like mine, did away with the +/- system. \n \nThe GPA:Letter Grade goes like this (usually): \n \nA/A+: 4.0 \nA-: 3.67 \nB+: 3.33 \nB:3.0 \nB-:2.67 \nC+:2.33 \nC: 2.0 \nC-: 1.67 \nD+: 1.33 \nD: 1.0 \nD-:0.67 \nF:0.0 \n \nNow, if you have an Honors course, that's an extra 0.5 for the course, if you have an AP course, that's an extra 1.0. \n \nIf you have A's in 4 regular classes (16 points), 1 A in Honors (4.5 points) and 1 A in AP (5 points), that is this 25.5 points/6 courses = 4.25 GPA. \n \nIn college, courses have different weights, Calc I is usually a 4-credit course and Chem I is usually a 3-credit course, so the math is worth 1/3 more, and you have to add those up. So a B in Calc (12 points) is the same ~~GPA~~ points as an A in Chem (12 points)."
] |
[
" I'll admit a solid half of what you wrote doesn't make sense to me, so maybe I'll need to write an ELI5 for how the U.K educational system works.\n\nHere's how it goes from the start:\n\nFirst you have preschool. Basically, children around 2-3 going and being watched. Often this is done so that parents can work, and some parents don't send their children to preschool if they'll be around them.\n\nThen there's the availability of kindergarten around age 5-6. Not required, as far as I know.\n\nGrade school (which encompasses grades 1 - 5 in America) is what we call the first few years of education, what you would call \"primary school.\"\n\nMiddle school (also called junior high, which encompasses grades 6 - 8 in America) has kids from about twelve to about fourteen.\n\nHigh school (there is an archaic form of calling it \"senior high school\" but no one does, encompassing grades 9 - 12) has kids from about 15 - 18. But, the limit on when someone can voluntarily drop out differs by state. In my state, you cannot drop out of high school of your own accord until 18.\n\nThroughout the entire process you will have a GPA, which stands for \"Grade Point Average\", and basically averages your grades. An A is worth 4.0, B is 3.0 and so on. So, if I get three As and two Bs, I would have a GPA for that semester of 3.6.\n\nMy guess would be that A-levels roughly correspond to the last two years of high school in America (junior and senior year).\n\nSubjects are largely picked of your own volition, and this is the point at which students bound for college often take \"advanced placement\" classes. Basically, classes which (if you pass a single test at the end of the semester) give you college credit.\n\nYou will also during that time take one (or both) of two tests which will go to prospective colleges/universities. The ACT (American College Testing) is scored out of 36. The SAT (Scholastic Assessment Test) is scored out of 2400. It used to be scored out of 1600, so it's possible to hear older discussions about \"perfect 1600.\"\n\nApplying for college is basically filling out the forms, sending your transcript, getting letters of recommendation, and writing \"why I want to go to your school.\"\n\nAt that point you go to \"undergraduate\" at a college or university. A college, for us, is what we call an undergraduate institution which teaches one thing, often it is a specific college *within* a broader university (which is just an undergraduate institution which has multiple colleges). The Kennedy School of Government would be one \"college\" within Harvard University.\n\nGraduate from undergrad, and you can (a) go work, or (b) apply for graduate programs. Strictly speaking, it goes bachelor's degree, master's degree, doctorate, but many programs let you get your master's degree while getting your doctorate.\n\nI have no idea what \"BAC\" would mean outside of Blood Alcohol Content, perhaps a reference to the International Baccalaureate Program? Or perhaps to the Bachelor's Degree?",
" Most of the education system is horribly underfunded, school supplies generally come from the teachers' salaries (which are already slim enough)\n\nIn addition to this, schools are awarded grants based on standardized testing scores, so the priority is for the students to be able to get good test scores so the school can get money. In this circumstance, the kids are treated as a means to an end rather than as a resource to be cultivated"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What are “pull-up” and “pull-down” resistors in a circuit?
|
[
" If you have an input to a binary circuit, that input at some point has to be decided on as either 0 or 1. If you leave that input 'floating', then random variations in charge can make the decision circuit unsure as to if the input is high or low. The solution is to provide a 'default' setting, which will overpower the noise associated with a lack of signal, but will be overpowered by an actual signal. So you can either connect it to ground, or power. You don't want to just directly connect it though, because it would overpower any input signal. You need a resistor. As for the value of the resistor, you can probably calculate it based on the characteristics of the digital circuit, but it's safe to say 1-10kohm.\n\nIf you find your circuit still has noise, decrease the resistance. If you find it has trouble changing away from the pull resistor, increase the resistance.",
" They are so a wire have a know voltage if nothing is connected to it and the output is connected to for example a transistor.\n\nA simple example is a button that is open if not pressed and closed if pressed. You connect the wire between the wire and +5V. When you pres the button the voltage is +5V but what happens when you release it? If the circuit on the other end use no current like a MOSFET transistor that might be the input of a integrated circuit the wire can float and still be at +5V for long time.\n\nSo to change the circuit to be 0V when the button is released you connect it with a resistor to ground. What size is needed? That is hard to say as a larger value result in slower change to 0V but a smaller value will let a large current trough it when the button is pressed. If what is connected is not a button with 0 resistans but something with resistance the pull down resistor will stop it from reach +5V and if it is to low value resistor the voltage might never get as higher as is needed. \n\nSo the complex answer is that the value of the resistor depends. Look at values other people have used in similar design and understand your constrains."
] |
[
" The knob is connected to a shaft that spins a 'wiper' over a little strip of carbon. The wiper is basically a tiny wire that turns. On either end of the carbon is another wire, usually connected to source or ground (or even the wiper). Because resistance varies with length, moving the wiper varies the length. Changing the resistance let's you control how much signal is passed through the resistor and how much is burnt off as heat. Turn it all the way one direction and all the signal goes through, turn it the other way and all the signal is dissipated across the resistor. \n\nNow that's really inefficient. You're amplifying the signal a bunch, then either sending it forward or wasting the energy as heat. \n\nA solution is to use feedback. The way it works is the input to the amplifier circuit is \"differential\" meaning it amplifies the difference between two signals. The resistor controls that difference. It brings the efficiency way up.",
" I'm not sure what you mean by 'modern day resistor.' \n\nSome materials trade electrons easily. Others, not so much. A resistor is just two conducting wires bridged by a less-conductive material (almost always carbon, but sometimes talc, rubber, or resin). The material resists the flow of current. Wiring resistors in series will increase the resistance. However, wiring resistors in parallel will paradoxically reduce resistance (because there are more paths for the electrons to travel, even if each individual path offers resistance)."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Can someone explain Linux, GNU and Unix?
|
[
" Waaay back in the 80s, there were two predominant operating systems. There was UNIX, which was powerful, expensive, everyone wanted it, but it could only run on particular hardware, and there was DOS, which could run on more hardware, but was not as useful. Both of these came with extensive license agreements, that, among other things, prevented people who purchased them from viewing the source code or changing the function of the software or using it for non-approved purposes. \n\nOne MIT researcher, Richard Stallman, didn't like that idea. He decided to found the Free Software Foundation, kicking off a naming convention that continues to haunt us. \"Free\" in this context means \"you can use it however you want\", not \"you don't have to give us money\", though most things that are the first are also the second. The FSF began production on GNU, short for GNU's Not Unix. What was GNU? It was Unix, pretty much. The FSF began rewriting all of the functions of Unix from the ground up, building an operating system that did exactly the same thing, but it belonged to them, and they could distribute it without license agreements. \n\nNow, the GNU project was successful. They had a complete, working copy of UNIX, well, all except for one part. The lowest level, most complicated part of the operating system, the part that actually talks to the hardware, and turns software commands into hardware actions, is called the Kernel, and GNU was still using the Unix kernel, and so they were still restricted to official Unix hardware. \n\nAt around the same time, we have a Finnish hobbyist named Linus Torvalds. Linus had a copy of Unix, and a Unix computer, but he also had a second computer that he wanted to run Unix on, but had slightly different hardware. So, he wrote a new kernel that would work with his new hardware. He then went on the early version of the Internet and said, \"Hey, everybody, check it out, I got UNIX running on X hardware, here's how I did it, here's the source code\". Then some other hobbyist sees this, he has some hardware that's just a little different from Linus's, so he gets Linus's kernel, plays with it, adds to it, and eventually gets it running on his machine. He then sends his changes back to Linus and Linus edits his original kernel with these new changes, and republishes it. So on and so forth, the kernel gets bigger and bigger, people start calling it \"Linus's Unix\" or Linux, for short, Linus invents a program called git to keep track of all the changes, and eventually they, using this new *open source* kernel, can get Unix running on just about any machine. \n\nEventually, these two guys found out about each other, and decided to put their software together, and voila! GNU/Linux, a new operating system, is born. It's as powerful and useful as Unix, but with no license agreements, and can be run on virtually any hardware with the power of Linux. Other groups and companies like GNOME, Debian, Canonical, Red Hat, Oracle, the Open Document Foundation, Apache, and the NSA come along and make contributions to the project, and over the course of the last 20 or so years, it's become the number one operating system for all computers, servers, microcontrollers, everything... except desktop.",
" Unix is a non-free operating system.\n\nGNU is a free set of tools written to behave just like Unix's. It works with different kernels.\n\nLinux is a free kernel written to behave like the Unix kernel.\n\nGnu tools and the Linux kernel are often bundled together to give a complete free o/s"
] |
[
" UNIX encompasses a family of operating systems with a long and sometimes twisted family tree.\n\nThere is also a UNIX standard body which provides certification. Any operating system that passes certification can call itself UNIX. There's also a set of published standards for interoperability called POSIX. Software may be POSIX compliant but not UNIX certified. Proven compliance with POSIX yields certification.\n\nPOSIX compliant software should at least be source compatible with any POSIX compliant operating system that has the necessary system libraries. Binary compatibility is also achievable with a bit of care. For example, a simple C program can compile into an ELF targeting Linux and linked against the glibc (GNU C Library) or an ELF targeting FreeBSD and linked against libc (UNIX C library). Since glibc and libc are both designed to adhere to the C standard library, and the C standard library is a part of the POSIX standard, their functionality is supposed to be identical. As a result, the Linux program should run on FreeBSD with only minimal additional kernel support to deal with differences in the ABI.\n\nSolaris (Sun, now Oracle), HP-UX (Hewlett-Packard), AIX (IBM), BSD (including FreeBSD, OpenBSD, and NetBSD), and Darwin/OSX (Apple) are all \"Genetic Unix\" in that they can trace their origins all the way back to the original Unix operating system created at Bell Labs. Many of these, including certain versions of OSX, AIX, and Solaris are UNIX certified.\n\nThere are also several Unix clones, such as Minix, Linux, and the GNU Project. There is no UNIX code anywhere in the GNU Project or in Linux yet both adhere to POSIX where necessary.\n\nThe GNU Project started as a completely open source and community driven Unix clone. A ton of user level software was developed, including a very nice compiler. However, the GNU Project's kernel, called HURD, was never completed and remains to this day somewhat of a joke. Rather, Linux, a separate kernel project developed to be compatible with UNIX software became the de-facto kernel for the GNU Project.\n\nAlthough development is performed with deep collaboration, the Linux kernel is not inextricably linked to the GNU project userland. In fact, the Android operating system use the Linux kernel, yet is completely devoid of GNU software. With a bit of tweaking, GNU software can also be used with the FreeBSD kernel.\n\nThere is no requirement that an operating system be \"genetic UNIX\" in order to be compliant with the POSIX standard or to receive certification. In practice, most POSIX compliant operating systems are not UNIX certified because doing so is expensive and adds very little value. Some brand themselves as \"UNIX-like\" but many do not.",
" When people talk about Linux, they can talk about two things:\n\nFirst of, Linux is a Open Source OS kernel inspired by Unix. A kernel is the core component of your operating system and allows software to interact with the hardware in an abstract manner (i.e. the software requests to write a file, the kernel is doing the low level talking with the hardware).\n\nSecondly, people also use Linux as the overarching term to refer to all the OSs build on top of the kernel, these are called distributions. As it is Open Source, everybody can take it and add additional software around it. Many have done so and distributions go by the names of Debian, Ubuntu, SuSE, Redhat and so on. \n\nNote however that whenever you see something graphical when people talk about Linux, that is generally not Linux. If you see shiny graphic effects or a GUI, that's generally KDE or Gnome, not Linux. While KDE and Gnome are often part of a Linux distribution, they are neither specific to Linux not do they always come with Linux. You can run them without Linux and Linux can run without them. They just happen to be popular in combination with Linux.\n\nTo make a car analogy: The Linux kernel is the engine. The Linux distribution is responsible for the rest of the car."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
does shaving with a razor on your legs dull the razor faster than using it on your face?
|
[
" You have a lot more leg than face. Shaving your legs once is like shaving your face 10 times."
] |
[
" You might actually be pushing too hard with the razor. Try to let your face soak in the shaving cream. Ive noticed that sometimes if i dont let the shaving gel sit for long enough on my face, ill get razorburn aswell. Try holding a hot cloth on your face before applying the shaving cream aswell. That has worked for me. If nothing works, you probably just have extremely sensitive skin. You might have to go out and buy an electric razor that doesnt cut as close to the skin as a normal blade would.",
" Many electric razors cut more like scissors where the hair has to go past a stationary guard which has a rotating blade on the other side. Feel a good pair of scissors and you will notice that you will probably not get cut touching the cutting edge, but a razor is much sharper than scissors. The cutting edge of the razor will wear down much faster than the scissors due to the sharper angle. Also some electric razors are self-sharpening due to the blade constantly rubbing against the inside of the guard which maintains the angle of the cutting surface."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How did the Roman Empire Fall?
|
[
" Remember that it could also be argued that the Roman empire didn't actually fall until the sack of Byzantium in the 1200's or even the dissolution of the Holy Roman Empire at the end of the 30 years war in the 1800's. When we talk about the fall of the Roman empire we generally mean the western empire but people forget about the east.",
" It didn't really fall, per se. People have just been saying that since Edward Gibbon gave his book a dramatic title to get sales. The central government in the western half of the empire took a big hit, but it was still there and still active even after 476. The people in the farther-away parts of the empire like Spain, France, and Romania kept chugging along, doing their thing, still speaking Latin, still using roman measurements and currency. It wasn't until Charlemagne introduced his Pounds/Shillings/Pence system that people stopped using Roman currency. The authority of central government in Rome itself contracted until it only really ran the Italian peninsula. After a few feckless fake emperors and a few barbarian chiefs, (simplification ahead) the remaining governmental administrative bureaucracy, including what was left of the military, was commandeered by the Bishop of Rome, and became what we now call the Papal State, which hung around until the mid 1800s.\n\nWe all know how things went in the East. Byzantium, Greeks, Turks, 1453, etc. Interestingly, the Ottoman sultan Mehmed II assumed the title \"Kaiser i Rum\" when he conquered Constantinople, and it remained as one of the official titles of the Ottoman sultans until 1922, when the Empire was dissolved.\n\nBelieve it or not, a small sliver of the original western Roman imperial government still exists today in the form of the Vatican bureaucracy, known as the Curia, which has been around essentially since Constantine the first decided that the whole Roman Empire was Christian."
] |
[
" WARNING: This is not an ELI5 answer, but more like an AskHistorians answer, since I actually will be using a book as my source. This will be very long and thorough, possibly taking up multiple long posts, so if you don't want to spend a considerable amount of time reading it all in one or more sittings, move on to a different answer.\n\n**Rome didn't so much as \"fall\" as it just changed.**\n\nThis is the general gist of *The World of Late Antiquity*, by Peter Brown, a book that revolutionized the historiographical discussion regarding Late Antiquity and the Early Middle Ages when it was first published in 1971.\n\nFirst of all, the Roman Empire *never* fell entirely until 1453. What we refer to as the \"Byzantine\" Empire is just a label given by more recent historians to differentiate between the Rome of antiquity and the more heavily Greek-influenced Byzantine Empire of the Middle Ages. The Byzantines still thought of themselves as Romans and of their history as an entity being one stretching unbroken back to the founding of Rome. The \"fall\" that is (somewhat arbitrarily) marked at 476 AD indicates the collapse of central political authority in only the Western Roman Empire, and even that is something of an arbitrary label because the central political authority of the Western Roman Empire had been eroding gradually for centuries.\n\nSecondly, the Roman Empire(s) by the 5th century AD were markedly different from the Roman Empire of the popular imagining. Its peoples had changed, its political and cultural institutions had changed for better or for worse, its majority religion had changed entirely, and its economic framework had changed. Furthermore, the Western and Eastern Empires were so different between themselves that they were by practically completely different political and cultural entities by the the point the Western Empire dissolved. And understanding those differences are *vital* to understanding why the Western Empire dissolved while the Eastern Empire did not.\n\nLet's start with feudalism. Feudalism didn't develop out of a vacuum (and it is hotly debated whether \"feudalism\" is a coherent system at all, because it certainly isn't monolithic). It wasn't introduced purely by the \"barbarian\" invaders. The transition from a centralized Roman administration to a decentralized feudal environment was already well underway, especially in the Western Empire, by the 5th century AD. This was due to the culture and shifting economic realities of the Western Empire. To be somewhat brief, the Eastern Empire gravitated more toward the autocratic rule of the Emperor, and thus kept its tax-collecting administration much more centralized; in the Western Empire, land and wealth was much more concentrated in the hands of a class of senatorial elites, who in order to keep their land and wealth more intact helped maintain the weakness of the Emperor's authority and even dismantled elements of centralized administration.\n\nHow did this happen in the Western Empire, you ask. Well for one, thing the Eastern Empire was always *considerably* more wealthy and better-developed than the Western Empire, for the eastern Mediterranean had a much longer history of organized polities. Additionally, this stark social division in the West ties heavily into other shifting cultural elements of Rome - heavily related to religion, meritocracy, and education. And to understand *that*, we have to go back to the Crisis of the Third Century.\n\n**The Crisis of the Third Century**\n\nThe 2nd Century AD was a golden age for the Empire. The Empire reached its territorial height under Trajan, and remained at high highs under the strong and wise rule of Hadrian and Marcus Aurelius. At the end of the 2nd century, a large civil war occurred, with the Severan Dynasty ultimately achieving stable power over the Empire; but this was not the Crisis. The Crisis was triggered by assassination of Alexander Severus, the last of the Severan dynasty, by his own troops. In the aftermath, multiple generals were proclaimed as Emperors by their troops, wracking Rome with the worst civil wars since the end of the Republic. And when the Emperor Valerian was captured and executed in 260 AD by Sassanid Persia in the East, the divisions exploded once again. The Empire was divided into three competing states - the Gallic Empire of Gaul and Britannia controlled by Postumus, the Palmyrene Empire of Egypt and the Levant controlled by Zenobia, and the \"legitimate\" Roman Empire controlled by Valerian's son Gallienus. This was all exacerbated by the growth of power by enemies beyond Rome's borders - Germanic tribes along the Rhine, and Sassanid Persia in the Middle East. Even as rival claimants fought amongst themselves, the borders of the Empire were being assailed by invaders and left unguarded. The Crisis did not end until political reunification was achieved by Aurelian and later reforms were pushed through by Diocletian in 284 AD, dividing the Empire in Eastern and Western administrations under co-emperors to make the entire unwieldy beast much easier to manage.\n\nThe Crisis was a complete breakdown of central authority in a world where technological and agricultural limitations made central authority a necessity to keep the Empire intact. The central authority of the Roman Emperor and his bureaucracy kept the trade routes open that allowed food to flow from the Mediterranean coast to the inland communities of the outer provinces - remember that in this period overland transportation of goods was significantly slower and exponentially more expensive than maritime transportation. And Rome was a victim of its own overextension - one Emperor could not possibly hope to efficiently administer the entire Empire alone. If the Emperor was defending the Rhine borders against Germanic incursions, how could he possibly hope to organize a defense against a Sassanid invasion in the Middle East? Communication and travel took an extremely long time to reach one frontier of the Empire from the other, and even after a message of invasion is received the Emperor still had to muster forces and organize a defensive campaign on the other side of the world! This was Diocletian's logic and brilliance in dividing the Empire - an emperor in Rome can more effectively and efficiently repond to an invasion across the Rhine, while an emperor in Constantinople was better suited to defended the frontiers of the Danube and the Middle East.\n\nBut simultaneously, dividing the Empire hastened the fall of the Western half. With the Eastern provinces being richer and more developed, the disparity in wealth between the separate political entities allowed the Eastern Empire to eventually far outstrip the Western Empire in institutional control and development. This disparity was so significant that despite the Western Empire's *considerably* better-suited natural frontiers, the Eastern Empire still lasted far longer simply because its wealth and continued centralization better equipped the Eastern Empire to respond to and defend against outside threats.\n\n**Cultural Fallout of the Crisis**\n\nBack to the aftermath of the Crisis. The Crisis allowed opportunities for the rise of \"new men\" within the Empire - military officers and soldiers from different regions and lower social classes within the Empire managed to penetrate the ranks of the upper classes that had been more distinctly \"Roman\" in their culture and ethnicity. These new men commandeered the bureaucracy and administration of the Empire, and were of disparate ethnic groups from well outside the Italian peninsula who differed from the classic Roman ethnic type yet still identified as Romans. Diocletian himself, for example, was the son of a freedman from Dalmatia, and he was the great reformer who ended the Crisis. These new men introduced a more military and meritocratic culture to the conservative upper classes of the Empire - they rose to the top, diversified the upper classes, and stayed there.\n\nWith the new men also came other cultural changes. New men meant a need for education, and they received the classical education normally reserved for the wealthy landowners. New men meant Christians began worming their way into positions of authority. And these new men assimilated into the upper classes, receiving their education, furthering their own careers and wealth, and ultimately adopting similar conservative, traditionalist views moving forward. The new men might have looked different, spoken different vernacular tongues, come from poorer backgrounds, and worshiped a different god, but they eventually became otherwise indistinguishable from those they had joined at the top. For both halves of the Empire, the 4th century AD was a period of renewed stability and rising hopes, a feeling that the golden age of the 2nd century could be renewed.\n\nBut with the continued rise of Christianity, tensions returned to the Empire, and this was not to last.\n\nI'm approaching the character limit, so I'll end it here, and continue in a reply.",
" Because they are well known events that a lot people have heard of, even if they didn't actually change much overnight.\n\nThe fall of the western Roman Empire and the beginning of the European middle ages wasn't exactly a single day event that changed how everything was governed. It was a decades and centuries long process of the Western Roman emperor delegating away power and territory that he no longer had the ability to effectively rule. Many of the major powers in a post-roman Europe already existed as major powers. The beginnings of serfdom and feudalism began way before the fall of the western empire, as part of the major changes to the economy and taxation made by Diocletian. None of these things suddenly occurred overnight when Romulus Augustulus was deposed and the warlords who had been propping him decided against asking the Eastern Roman empire to acknowledge a successor.\n\nWith the fall of Constantinople, it is again an oversimplification. The city and empire were way past their prime by the time the Ottomans actually managed to conquer the city. It was an easy historic simplification to just say that the invasion caused all of the scholars to flee the Italy and start the renaissance, but again these were long running processes. Italy had already been working to become the main power on the Mediterranean, and the wealth allowed for greater and more elaborate construction, art, and scholarship. Italy had already been rebuilding itself with many major trading and banking institutions, and after the fourth Crusade (which led to a European conquest and sacking of Constantinople) Italy had become the preeminent trader on the Mediterranean."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How are expiration dates so precisely determined?
|
[
" I used to work in a video store that sold confectionery items. Every couple of weeks I'd go through all the junk-food stuffs with a sheet that explained how every manufacturer (that we carried) explained their expiry dates.\n\nI'm not home right now so I can't give you a solid example from a copy of the sheet I kept, but numbers could mean: day, week, or month it was made (or expires), it could also mean # of the factory it was made at, or batch number on that day. It could also have meant best between dates, for those goods that are aged to perfection. \n\nI vaguely remember one barcode that had a 9-13 alphanumeric code and deciphering it was a pain I had to relive every couple of weeks. First world problems. \n\nI guess it doesn't exactly answer your question. Have you tried Googling the juice box manufacturer along with the appropriate query to determine what the expiration code decodes to?\n\nJuice boxes/bottles don't *really* expire. I've got some at home that's 4 months \"past due\". As long as you drink it in the next couple of hours it'll be fiiiine."
] |
[
" Expiration date is the manufacturer's guarantee that the product is within their specifications.",
" Experation dates does not mean that it goes bad at that date. It means that this product is guaranteed to not spoil by this date. \nNaturally the date is a lowball estimate and may last for much longer. Other stuff got a experation date by law like Eggs (Europe) but last much longer than the date stamped on them. Infact my granny will not bake anything unless the eggs are 5 weeks past experation and she make the best pancakes/cakes ever."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How did countries establish whether they would drive on the left or right side of the road?
|
[
" Archaeological evidence suggests that the ancient Romans may have driven their carts and chariots on the left, and the practice seems to have carried over into parts of medieval Europe. The reasons for this are not entirely certain, but some believe it arose as a matter of safety. The majority of people are right handed, one theory goes, so driving or riding on the left would have allowed them to wield a weapon with their dominant hand if they crossed paths with an enemy.\n\nIn the United States, meanwhile, many researchers trace the beginning of right-hand traffic to the 18th century and the rise of freight wagons pulled by large teams of horses. Since these vehicles often didn’t have a driver’s seat, drivers tended to ride on the left rear horse to more easily control their animal team with their right hand. As the wagons became more popular, traffic naturally moved to the right so drivers could sit closer to the center of the road and avoid collisions with one another. \n\nHistory. com"
] |
[
" In britain we used to walk on the left side of paths/roads because most people were right handed and consequentialy wore their swords on their left, if they walked past someone on the road and had to defend themselves, then the guy they were fighting would be on their sword side, which is why to this day, we drive on the left side of the road, it is just a natural evolution of old tradition.",
" Initially, almost everyone would travel on the left side of the road, as it was the wiser choice in more violent societies since most people are right-handed, swordsmen preferred to keep to the left in order to have their right arm nearer to an opponent and their scabbard further from him.\n\nHowever in the 1700's, teamsters in France and the United States began using very large wagons to transport farm produce. These wagons were usually pulled by multiple horses and the driver sat on the rear left horse leaving his right hand free to control the rest of the horses. \n\nAs a result these wagons preferred people passing on the left to ensure they could see how much space there was to move ensuring they don't hit any other passing wagons and eventually became a standard.\n\n & #x200B;\n\n**REFERENCES** \n[_URL_0_](_URL_0_)"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Food is made up of fats, carbohydrates, and protein, but what gives different foods their flavor and how do they work?
|
[
" Because there are *far* more substances in food than just carbs, fats, and protein. Those are three macronutrients, but there's also micronutrients and thousands of other chemicals present as well. Salt, for instance, is not one of those three, yet you have an entire taste bud set dedicated for that one chemical."
] |
[
" Most food you eat is made up of long molecules. For example, if you eat bread, that has carbohydrates, which are long molecules made up of sugars. But they're not complete sugars! A simple sugar molecule has the formula C6H12O6. It's usually a ring structure thingy (I don't know, I haven't studied organic chemistry). An example of this is glucose. Now, if you put two of them together *and take away two hydrogens and an oxygen to link them*, you'll have a more complicated molecule made up of two simple sugars and a water. This is called dehydration synthesis, because you synthesize a longer molecule out of two smaller ones by taking out a water molecule. So if you want to link a whole bunch of sugars together, you need to remove the atoms of a water molecule every time.\n\nThing is, your body uses the simple sugars, but it's the long chains of them that come in food (these are called complex carbohydrates, since they're complex molecules made of carbon atoms and the equivalent of water molecules). So it has to break up the long chains. You take two hydrogens and an oxygen *out* when you join them, so if you want to separate them again, you need to add that back! It takes water to split a complex carbohydrate. (It also takes time, which means you don't get all the sugar into your blood at the same time. Getting all that sugar at once is bad for you, so complex carbohydrates are better in that sense.) So since you're splitting all those complex carbohydrates, you need to use up water, so your body starts doing that, which makes you thirsty.\n\nSalt actually dries you out for completely different reasons!",
" Well sonny, there's things you eat called \"**macronutrients**.\" That's just a big fancy word for \"stuff you eat that can be turned into energy\". The \"**macronutrients**\" are **carbohydrates, proteins**, and **fats**. The common thing with all of the \"**macronutrients**\" is that they're all made out of mostly **carbon** and **hydrogen**. \n\n**Carbohydrates** are different types of **sugars**. The tasty **sugar** in your candy, called \"fructose\" by scientists, is only one type of **sugar**, but there's others. The most common is \"**glucose**,\" which is used by your body to make energy the easiest. A single molecule of glucose is shaped like a hexagon. The cool thing about **glucose** is that all those hexagons can be linked together in giant chains and balls. You body puts **glucose** together in giant chains and balls called **glycogen**, which can be stored in your muscles and liver, but that's another topic. \n\n**Proteins** are made out of things called \"**amino acids**\" which can be linked together to make complex structures in your body like muscle or **enzymes** (**Enzymes** are **protein** structures that can make other proteins, build structures in your body, and facilitate-that means take charge of-chemical reactions in your body. They're like little tiny chemists. Again, that's another topic.)\n\n**Fats** are big long chains of **carbon** and **hydrogen**. Instead of being ring shaped like **sugars**, **fats** are big long lines of **carbon** and **hydrogen**. Because of their shape, **fats** can store a lot of energy in a smaller amount of space and weight than **carbohydrates**, but they take longer to turn into energy than **carbohydrates**. It's kind of like an electric car. The electric car is a lot more efficient, but can't go as fast as a gas car. Again, that's another topic. I keep getting carried away. Sorry.\n\nAnyway, remember how I said that all the **macronutrients** are made out of mostly **carbon** and **hydrogen**? Well, that makes it so they can be converted to one another (except **fats** and **carbohydrates** can't be converted to **protein**, because **protein** has some extra stuff in it besides **carbon** and **hydrogen**. Again, another topic.) Your body has a whole bunch of tiny, microscopic chemists, called **enzymes** (remember that word?) that build and reshape stuff. These **enzymes** can reshape **macronutrients** into different versions.\n\nSo, when you eat **carbohydrates**, you turn some of it to energy, and turn some of it into **glycogen**, (remember that word?). If you eat a whole bunch and don't have any more room for **glycogen**, some of the **sugar** rings get re-shaped into **fat** lines so they can be stored more easily in less space and weigh less for how much energy they can give you.\n\nWhen you eat **proteins**, some of it gets used to build stuff in your body, like muscles and more **enzymes**. If you're starving and don't have much **fat** though, the **protein** that's used to build your body gets broken down by the **enzymes** into **sugars** so that your body can keep making energy and keep running. (Your body actually starts eating itself when you're starving!) If you eat a whole bunch of **protein**, the **protein** you don\"t need to build your body structures get's reshaped into **fat** lines so that you can have energy stored. Remember how I said **protein** has some other more complicated stuff in it besides **carbon** and **hydrogen**? Well, that stuff gets thrown in the garbage, also know as your bladder, and you pee it out.\n\nMost **fats** are stored as energy since they're so space and mass efficient. Some other **fats** are used for special purposes in your body like keeping your joints lubricated and keeping your brain healthy.\n\n------------------------------------------------------\n\nTo answer your second question, evolution 1) only works just good enough to keep us from dying before making more babies, and 2) is usually a very slow process. Even if we get fat and sick by the time we get older, we still have had plenty of time to make babies without getting eaten by lions. Also, the problem of not having enough energy from food is a much older problem than getting too fat, so we're still built to do our best and survive with little food.\n\n--------------------------------------------------------------\n\n**EDIT**: Bolding all those words was a real pain in the butt, so you better appreciate it! \n\nThe bottom line is that if you eat more **macronutrients** than you need for the energy that you spend, you gain weight. That weight can be **proteins** building your body bigger, **fats** being packed up to store energy, or both. If you eat less than your body needs for the energy that you spend, you lose weight. That weight can come from converting and burning the **fats** that you've stored, or if you don't have much **fat**, the **protein** that makes up the important structures of your body (which is usually a bad thing).\n\nI simplified this as much as possible while remaining accurate, but I think the minimum age to understand this is probably about 7 or 8."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does fabric turn darker when wet?
|
[
" if you put a tissue over another tissue and so on, it keeps getting darker because one tissue fills the gaps that let's light through of the first tissue. Water does the same with fabric. It let's less light through because the water fills the gaps. It also refracts light towards the fabric etc."
] |
[
" It's because of how the water interacts with the surface of the fibers. If the fibers have a polar structure that is similar to water (hydrophilic), they tend to absorb more water than fibers that have an unpolar structure (hydrophobic). Hydrophilic fibers not only absorb more water, but they also take longer to dry because the water is more strongly bound to the surface. In less hdyrophilic material, just spinning can be sufficient to remove most of the water, so that the material will feel dry or almost dry when you take it out of the washing machine.\n\nThe tracksuits that you mentioned are often made of a water-repellant material, with the purpose of *preventing* them from absorbing sweat, which means they are made of mostly hydrophobic materials.\n\nAnother factor is thickness and how the fabric is woven/structured. The thinner and more penetrable it is, the more easily the water from washing can be removed by spinning.",
" The colours we see are entirely dependent upon the light reaching our eyes.\n\nFor example, if you are wearing a blue shirt, the fabric is actually absorbing all the *other* colours, so that only blue light is reflected back at you. \n\nIf you pour water on the shirt (i.e.: make it wet), you're now adding a new, different variable. H20 is now seeping into and mingling with the cloth, and we know that water causes light to be *refracted* (i.e.: scattered) at different angles.\n\nThis means there is now less light reaching your eyes (because some of it is scattered away). Less light from the 'wet region' means you are literally seeing \"less light\", and thus it will look darker."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
If we're biologically programmed to find babies cute - why do so many people not find babies cute?
|
[
" I’d say that humans are not biologically programmed to find babies cute. We actually are biologically programmed to protect our children. We also tend to protect things that are cute. They’re exclusive to each other."
] |
[
" What do humans find cute? [Anything that's similar to a human baby](_URL_3_) -- big eye/head size ratio, tiny arms, short, etc.\n\nWhy do we find things cute? So that we actually raise our kids instead of abandoning them [like \\(some of\\) the dinosaurs did](_URL_3_). I can't confirm this off hand (saw on a history channel special ~4 years ago [walking with dinosaurs?]), but some of the carnivores would actually try to eat their newly hatched young! Why? Because they didn't have our \"Aww, it's so cute!\" reaction when they see the little buggers.\n\nWhen you see something cute, the last thing you think of is eating it, and the first thing you think of is protecting it like it's your own baby.\n\nCats are fully aware of this; they [mimic human babies](_URL_3_) to convince us to give them free food.",
" It had to have come from humans’ natural instincts to protect our (cute) babies. Humans instinctually care for and protect their offspring, which may include aggressive behavior. Given that in most situations, observing a baby is often not as dangerous as it was for our ancient ancestors, the aggression remains, ready to come into play at any moment something threatens our offspring. \n\nApplying this to cute things in general (since cuteness is a relative and general feeling, along with aggression) gives you a pretty solid answer.\n\nTL;DR Aggression from cute things probably came from our natural instinct to protect our cute babies."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does increased humidity cause things to smell more rancid?
|
[
" * our smell is more acute when it is humid\n* humidity *makes* things go rancid more quickly",
" Because humidity activates your smelling way better, for example everything smells way more intense in the shower, it could also be from the humidity clearing out your nose"
] |
[
" Part of it is that with less heat, there are fewer smells in the air. They get trapped in water vapor that then condenses on cold surfaces, bacteria decompose dead stuff slower due to cold, there is less heat to excite material enough to have smell be dispursed. \n\nThere is also less living plant life to pump smell into the air.",
" Water in general actually makes smells more obvious. Go fart in the shower and find out. \n\nIf I remember correctly it's because water has no actual smell and it allows other smells more \"room\" to be noticed. This is also why the myth about running across a river or stream to get away from a bloodhound isn't true, it just makes you easier to track."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
The Enclosure Law during the Industrial Revolution.
|
[
" Prior to the Industrial Revolution, there are plenty of privately owned lands in the countryside. People are free to graze livestocks or do whatever they want on those lands. This is called the Open Field System. \n\nDuring the Industrial Revolution, factories can process large amount of raw materials and have a higher demand of them. To supply the demand larger farms began to either restrict open fields access or force smaller farms to sell out because they are unable to graze their own livestock. This is the result of lobbying by wool merchants."
] |
[
" The thought being private companies can run an institution such as a prison more efficiently (monetarily) than the government. \nAlso the 13 amendment abolished slavery, except as a punishment for a crime. Chain gangs can make the prison money.",
" Industrialization.\n\nThe primary limit on scientists isn't really their imagination so much as the instruments they have to collect, process and verify information about the natural world.\n\nThe revolution of the 1800s was the rise of easily accessible, high-precision instruments and tools. Being able to apply consistent and predictable heat, being able to precisely measure mass, etc. - these allowed scientists to examine the world in ways they could not previously."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What happens when we crack our back and why does it feel good?
|
[
" Cavitation (which is the pop you hear from cracking your back), is a release of nitrogen gas in the fluid that is inside of your joint. Essentially, a pocket of gas is formed from the brief separation of the joint surfaces, which causes the popping sound. \n\nCavitation is associated with a neurophysiological response that isn’t fully understood, but we do know that there is frequently a reduction in muscle tone around the area that is “cracked”— in other words, the muscles become less tense. Additionally, we know that there are “top down” processes— in other words, feel good chemicals are released from your brain to help reduce perceived pain/stiffness/discomfort. \n\nThere is no definitive evidence that bones can be “realigned” or “put into place”, but that is something that has been perpetuated over the years by old school chiropractors and physical therapists. \n\n_URL_0_\n\n_URL_1_\n\nSource: I’m a physical therapist, who loves reading and learning about pain and anything related to our treatment!",
" The pop sound is as described above but that is not what causes the relief.\nThe reason the gasses build up is due to the chronic nature of muscles being tight and stretched pulling on the vertebrae, creating tension and imbalance. When you \"pop\" your back, (short and sweet and not getting into the physiology of it) the muscles \"reset\" back to neutral and allow the bones and muscles to relax and realign properly. The realignment is the relief you feel. \n\nSource - I am a osteopathic physician who loves OMT"
] |
[
" When you pull joints apart synovial fluid rushes in to fill the void left behind by gasses. So when your back doesn't crack you just don't have enough buildup between joints.",
" Because it's never passed actual scientific tests in regards to its claims. The tests that claim that they did show benefits are normally done by chiropractors who rely on anecdotal evidence. There was a scientific test in which the person administering the test cracked their own knuckles as they manipulated the subjects' spine. The subjects who heard the cracks and thought it was coming from their own backs reported greater healing than the ones who didn't hear any cracks. There's obviously no known healing properties in someone else cracking their own knuckles and your back pain disappearing, unless of course it works by the placebo effect."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
The scene in Trading Places with Dan Ackroyd and Eddie Murphy where they drive the stock price down and make millions of dollars while at the same time bankrupting the Duke Brothers. How does this work?
|
[
" Recent thread on this: _URL_0_\n\nOlder thread on this: _URL_1_\n\nMy Answer from older thread:\n\n/u/Pobody is right, but to clarify a bit, here's the stages (numbers are made up, just to illustrate):\n \n1.) **That morning** - The Dukes have a fake crop report, saying that there is an orange shortage. They take out a short term loan so that they can buy orange futures at the current price. Say the price is $10, because people are unsure of whether there will be a shortage.\n \n2.) **That afternoon** - Murphy and Akroyd show up. The price now is at $15, because the Dukes, and many others following the Dukes, have been buying all day, driving up the price. Murphy and Akroyd start to SELL. They don't own any shares (or own just a few), but that's alright, since they don't have to \"settle up,\" meaning actually give the shares they \"have\" to the person buying, until the end of the day.\n\n3.) **Just before the bell** - the crop report comes out. There is no orange shortage. Now, the price drops from $15 to $5, since everyone knows there are too many oranges, and so everyone starts selling. Once the price gets low enough, Murphy and Akroyd start to buy, which is easy, since everyone else is trying to sell. They buy enough to cover the sales they made earlier in the day, and pocket the difference (15-5 = $10 per share). The Dukes, on the other hand, are stuck. They sell what they can, but every sale is a loss.\n \n4.) **after the bell** - the Dukes haven't made enough to cover their short term loans. They are bankrupt.\n \n5.) **way after the bell** - Murphy's unrelated, identical twin, a wealthy African Prince, happens upon the Dukes living on the street, gifts them tens of thousands of dollars. they are back.",
" They had stolen the report on the orange crop, and gave a fake one with the opposite information to the Duke brothers. In reality, the crop was fine, so oranges would end up being cheap, but the fake report said that the winter had destroyed much of the crop, which would have made oranges more expensive.\n\nSo the Dukes, thinking that oranges were going to get really expensive, instructed their man to buy as much FCOJ shares as possible, as they would gain value after the report came out. As they buy, the price goes up. Then when the real report came out, the price plummeted and the Dukes lost all their money.\n\nMeanwhile, Akroyd/Murphy did the opposite--they sold FCOJ at the high price caused by the Dukes' purchasing, then bought it back when the price plummeted. This is called *short selling*, a stock market trick where you \"sell high, buy low\", as opposed to the traditional \"buy low, sell high\"."
] |
[
" [NPR did a radio segment on exactly this.](_URL_2_)\n\nTL;DR: [short selling](_URL_1_), based on [inside information](_URL_0_).\n\nOrange juice is being bought and sold. The Duke brothers think the orange harvest was bad, because Winthorp (Aykroyd) and Billy Rae (Murphy) have given them a forged crop report, supposedly stolen from the government.\n\nThe Dukes decide that when the crop report is publicly announced, the price of OJ is going to go way up -- there's less of it than people thought! So they decide to buy up the OJ. That's what happens in the beginning of the scene -- the Duke brothers have a guy on the floor buying up the OJ. As he buys up all the bargain OJ, he has to pay more -- the market price goes up, up, up.\n\nThen Winthorp and Billy Rae go into action, selling OJ. They don't actually have any OJ yet, but that's alright -- the sales aren't settled until the end of the day. So as long as they buy OJ later in the day, they'll be fine. This is called \"short selling\" -- basically hoping the price will drop, doing the whole \"buy low, sell high\" thing in reverse order.\n\nThen the crop report is announced. Turns out there's plenty of OJ for everyone! The price plummets. Winthorp and Billy Rae buy up discount OJ, and make a fortune. The Dukes sell out, hoping to save what they can, but when the exchange closes they're ruined -- they bought high and sold low.",
" The pump and dump scheme? I've only seen the movie once when it first came out, but I'm pretty sure that's what it is. Basically you buy a crapload of low value stocks and create a buzz, causing others to buy which increases the price. Once it hits a certain point you sell all your shares at a profit. Its market manipulation which is illegal. I'm not a lawyer though so I may be wrong."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
When applying a little bit of pressure on your closed eye lid, what is the circular looking thing you see on the opposite of where the pressure is being put?
|
[
" Your eye is like a bowl with a bunch of \"cameras\" facing and sensing light perpendicular to where it is located. So if the eye in question is the left, the receptors closest to your ears are essentially \"viewing\" objects across it, and in this case it is objects to the right and across your nose. So when you push on the eye on the temporal/closest to your ear, the pressure on the receptors in that localized area cause it to sense a change in viewing conditions and are stimulated, so your brain perceives it as an \"object\" to the right side. The black circle is the shape of the pressure you inserted on the eye and is where the photo-receptors are being distorted. Essentially where the receptors are at in your eye will view the opposite direction. Ex) receptors near at the top of the eye views objects towards the ground. At least that's my understanding of it."
] |
[
" I've never heard of what you described; most people see random patters of colors kind of like looking through a kaleidoscope....It's called an \"entoptic phenomenon,\" meaning that it originates from the eyeball. When you apply pressure to the eyeball, you also put pressure on the retina, which is basically the part of the back of the eye that turns light waves into brain waves. \n\nWhen you apply pressure to the retina, two things happen....you deform the retina slightly and essentially make the photo receptors (specialized cells that pick up light and send info to the brain) fire manually. It may also affect the cells' ability to pick up oxygen from the blood. The retina has one of the highest metabolic rates of any tissue in the body, and if you disrupt its oxygen supply for even a fraction of a second, they may start abnormal firing activity and sending random signals to the brain, leading you \"see\" random light and color patterns.",
" Is this anything to do with the fact that when you press, for example, lightly on the bottom left of your left eyeball, you see a dark ring with an orange outline around it appear in the top right of your vision?"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why haven't I ever see a commercial from a random person who decided to purchase air time?
|
[
" They are laws about what can be aired, but it is varies from country to country. It is also extremely expensive to buy any kind of air time for advertising. As well, stations don't have to allow someone to air a commercial just because you have the money. They are allowed to deny someone the service if they want. Most stations do not want to air commercials that will make them look bad.",
" Hey, I used to work in commercial airing! I can answer this! \nSo, commercials don't actually work by \"buying air time\". They have a bidding system, tied to a contract! \nBasically, it goes one of two ways- they get put in a bid, and if no other commercial puts in a higher bid for that time range, they get aired, they pay the contract! If not, they don't get charged. \nThe much more common one is that they pay for x-amount of airings on certain channels between certain time of day. If they get outbid, their commercial get pushed to another day with a few bonus airings. \nSo, sometimes if one set of people bid high in a narrow window, you'll see like 8 of the same commercial in two hours- they basically won their bid outright, and just shotgunned their first ideal airing window. \n \nUsuuuually only the poorer/cheaper clients put in for the might-make-it-on the air version, which is why you rarely see a commercial from a random wierdo- they rarely bid enough on their contract. \n \nThe other issue (and this is the department I worked in) is that those dumbasses can't follow simple standards. There's very few digital delivery services an encoding department will take (usually a list of about 4-5), and usually only 3 forms of physical media. The digital media also has to fit the right formatting rules (audio and video decoding, fps, filetypes, etc) or the system won't handle it properly. We constantly got broken tapes, improperly formatted files, tapes we didn't even have the equipment to play... or flat out the wrong commercial (we had to match media name to contract name. You'd think they'd try to make them the same... and you'd be wrong)\nThe commercial HAS TO be less than a second over their timeslot (15, 30, 60, 120 seconds), and no more than a few seconds short of the full timeslot (we could put in some blank filler to elongate commercials a bit). \nThey also hafta SEND US THE DAMN MEDIA ON TIME. Which is shockingly difficult, apparently. \nIf they fail any single one of those requirements and can't fix it in time (by our 6 PM deadline, when the airing schedule is created) , their contract is more or less void, and they hafta either renegotiate their bid, or just give up. \nafter 2 or 3 failed attempts, they usually give up."
] |
[
" Part of the reason is because each commercial passes through a focus group and multiple stages of testing. These test groups give their feedback, but they only see the commercial a couple of times at best. \n\nWhen the commercials for a company as large as Geico hit the national market they often have huge amounts of airtime for their commercial to play in. As consumers we end up seeing the commercial multiple times a day for sometimes months on end. Focus groups and surveys can only tell you so much. \n\nThe obnoxious pig screaming Weeeeeeeeeeeeee actually received very good ratings in focus groups and surveys... then it was played on repeat and drove people crazy. (source: I had a guest speaker from Geico teach in one of my Marketing classes in November 2012 who admitted this) Hindsight is always 20/20.",
" I've worked a TV station for the last 8 years. Every station operates a little bit differently, but the general idea is the same everywhere. Most stations have a sales team that sell commercial time to businesses. When the commercial airs depends on how much they want to pay, which depends on what time they want the commercial to air.\n\n\nFor example, airing a commercial in prime time is more expensive because more people are watching and the air time is deemed more valuable. Every time a commercial airs it has to be paid for. We don't have the freedom to pick and choose what to air when because they paid to have their commercial air during a certain time slot.\n\n\nOnce the spot is sold, we have to acquire the commercial. We will usually get it from an external company either via FTP or a number of specific services dedicated to commercial distribution. We also have an internal production team. Once we have the commercial in house, we prep it for air and it goes in a huge server that houses all the commercials that air at our station.\n\n\nOnce everything is ready to air and the order of commercials is determined, our automation system takes over and it basically becomes a large playlist that plays each spot at its determined time (time triggers we call them). This is only for programming that isn't live, though. For regular prime time shows, the network sends us down a list of timings for when exactly each commercial break airs during that show.\n\n\nLive programming is a little different. For our live newscasts, there is never a set time because it would be impossible to get the timing right every segment of every show. So basically there is a commercial break cued up and ready to go. When we go to commercial break, we can trigger it. We have control over that. It's the same for sports. There are national breaks that the network runs and local breaks that we run. We get a rundown of how many commercial breaks there will be during that particular game and which commercial breaks are national and which commercial breaks are local.\n\n\nThe situation with Fox News and the guy committing suicide was a situation where they had a commercial break ready to go since it was live and they triggered it right away, though it was too late."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What is the difference between volts, watts, and amps?
|
[
" Picture a waterfall. \n\nVolts are how high the waterfall is.\n\nAmps are how much water is flowing over the falls at any given moment.\n\nWatts are how hard the water hits the bottom of the falls.",
" Here's a pretty easy analogy:\n\nImagine a fire hose. \"Volts\" are a measure of water pressure. \"Watts\" is a measure of the diameter of the hose. \"Amps\" is a measure of how much water is coming out of the hose."
] |
[
" volt - a measure of electric potential (the difference in charge between one area and another)\n\nWatt - a measure of power (energy/time)\n\nAmp - a measure of electric current (how much charge flows through a space in a given amount of time)\n\nOhm - a unit of resistance (basically how difficult it is for charge to flow through something...things with high resistance take lots of energy to shove a current through and give off lots of heat when you do).",
" Volts(V) are a measure of voltage, \nAmperes(A) are a measure of current, \nWatts(W) are a measure of electrical power. \n\nA common analogy is a garden hose: \nVoltage is equivalent to the water pressure in the hose; \nthe current is equivalent to the flow rate;\nthe electrical power is equivalent to the volume of the spout’s spray. \n\nThe formula to calculate the final electrical power is:\n\nW = V*A\n\nSaid that, you can increase the resulting electrical power by increasing the Volts and/or the Amperes. There are several standards and each one has its own numbers, and compatibility with other standards. If you want to read more and check the specific details of each one, check the source:\n_URL_0_"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why is it that most singers close their eyes when singing?
|
[
" Why do I stick my tongue out when learning new song on my guitar? No doubt the act of closing their eyes can be part of the performance, for show, but it is also part of getting into the moment, concentrating, and settling nerves. I don't know of any studies on the topic and a quick search didn't turn up anything too specific (I didn't look super hard). When concentrating on one thing intently most people have \"autonomic\" responses that are not consciously done. Even when a skill is mastered closing ones eyes can increase hearing or touch. \n\nI don't know if there is one answer to your question, because it would depend. That is the most common answer to psychological questions: it depends."
] |
[
" Assuming the people describing the singers voice know the difference between flat and sharp, I would say that it is more common for a singer to sing flat than sharp. This is because singing involves efficient breathing and usage of the diaphragm. When singers don't sound in tune, most of the time it's because they are not breathing correctly or their technique begins to break down. The singer's voice will attempt to hit the notes but sometimes fail to 'reach them' and settle for a flatter pitch.",
" Singing is a conscious effort, much like moving around your arms. Holding a note is basically the same as, say, holding up a book with an outstretched arm -- except this time, you are supposed to keep that arm held up at a specific angle. It takes effort to keep that arm steady, but sometimes you would under/overestimate the 'output' of how much effort you put in that and your arm might slightly fall/raise. That fall or raise could result in a voice crack.\n\nTemperature plays a huge part in a singers voice, as do some beverages. Cold water cools your vocal chords too quickly, resulting them in tightening to soon. Milk builds phlegm, which causes you to sound stuffy. Sugary foods/drinks can mess with the lining of your throat.\n\nSource: I've been singing for ten years."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why isn't the minka building style used anymore?
|
[
" I remember talking to my innkeeper about that when I stayed in Shirakawago, and basically it is very expensive to maintain any of the traditional thatched buildings. There are few people who have the knowledge anymore, and the techniques are quite labor intensive. \n\nThey maintain those roofs because they are a tourist attraction (and are World heritage listed, but in other places they are disappearing, even though you'd think it would be worth it too keep them. \nI remember staying at a gorgeous thatched roof traditional inn at Mt. Mitake, but when I came back a few years later it had been replaced with tile. That was such a disappointment. \n\nI know there is a grassroots movement which has the support and involvement of architects to maintain and restore the traditional Japanese farmhouses. I'll try and remember what it's called. \n\nHere you go : [The Japan Minka Revival Association ](_URL_0_)"
] |
[
" I believe that it's just you not perceiving them or that they blend into the structure. They are used on almost every structure now.",
" Because noboby wants them. Their burnt out, dilapidate houses that would cost thousands to make livable. Nobody wants those houses for a reason."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How come the upcoming solar eclipse is causing anxiety about the loss of solar power generated, but it's no big deal if it's a cloudy day?
|
[
" Rooftop solar contributes a significant enough portion of every to the grid that if it all stopped all at once the voltage drop would cause brownouts/blackouts.\n\nThis isn't a problem from cloud cover because that doesn't fully block solar irradiation and doesn't effect all solar generators all at once. Night isn't a problem either as it is easy to predict and happens every day.\n\nAn eclipse very quickly knocks out effectively 100% of all solar power in a very large area all at once. Much faster than the onset of night. This kind out event is rare, and difficult to predict how it will impact the grid."
] |
[
" This is generally because of the weather at night. At night the ground radiates heat in the form of infra red light. Clouds are largely reflective of infra red, so if it's cloudy the heat gets trapped and its warmer the following day. If it's not cloudy the heat is lost and the next day is colder.",
" When the sun is out it is very bright. That bright light from the sun saturates out the colors. On a rainy day or cloudy day you don't get that saturation of sunlight. It's like the difference of have the volume on the TV all the way up as opposed to half way. You can still hear everything but it is painfully annoying. Same thing goes for your eyes when there is too much light."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How can 600 cell phones all connect to the same tower on the same frequency? (Yet impossible with WiFi?)
|
[
" They don't all use the same frequency at the same time (with the possible exception of CDMA, but that's a long story). The frequency range that the tower can use is divided up. And each of those portions (in some schemes) share each portion at different times. They are allocated a time slot, and take turns.",
" It' not that it's not possible with wi-fi. My university has considerably more people connected than 600 at any given time. It's that the hardware for a cell phone tower is significantly more expensive and robust than the hardware in a wi-fi access point. \n\nPlus, cell phone towers work on a frequency spectrum that you have to purchase to use. Wi-fi works on a public available spectrum. So it's the difference between owning a car and riding a bus. Wi-fi is always going to have more interference than a cell phone because the cell tower has exclusive access to the frequency. \n\nIn addition because frequency is VERY expensive, you want to make the best use of it. So while there is very little incentive to connect 600 people to the same wi-fi point, there is lots of incentive to build fewer cell towers that work with a narrow frequency. \n\nSo the reason it's possible is because we need it to work that way, so we dump a big pile of money on it and they make it work."
] |
[
" Because for safety reasons, if the cell chip can connect to a single cell tower, they can still call 9-1-1.\n\nI had a friend who lived in not the most friendly neighborhood and even though she didn't have a cell phone that could call friends or family she charged it and carried it with her 24/7 in case of emergency",
" Hundreds to thousands of phones share a single base station (a \"cell\") which sends data to and from them using a limited range of radio frequencies. Its capacity is limited. If everyone decides to watch Netflix on their phones all day, the carrier needs to install many more cells, at great expense."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
What does the US get from Israel that warrants such dogmatic support? And is Israel the only country the US can get that from?
|
[
" There are a number of reasons for this.\n\nFor starters, there is a firm tradition of Jewish influence in the United States. After Israel, there are more Jews in the USA than anywhere else on the planet-- between five and eight million, depending on how religion and ethnicity are constructed. The Jewish vote [consistently] (_URL_2_) predicts the presidential election; Jewish groups have considerable clout in lobbying and politics. Anti-semitic stereotypes notwithstanding, there are a lot of prominent Jewish business owners, particularly in finance and banking: Goldman Sachs, Bloomberg, Citigroup, Kuhn, Loeb & Co., etc. They are also prominent in other business, particularly publishing and media. [Here are some prominent Jewish businessowners.] (_URL_0_)\n\n\nThe evangelical vote is actually *not* a very substantive indicator of US support of Israel, because the evangelical movement really only gained traction in the US in the late 20th century:\n > In the 1980s and ’90s the Evangelical movement greatly expanded. The reconciliation of conservatives from the Reformed tradition (Presbyterian and Baptist) with those from the Methodist tradition (Holiness and Pentecostal) was an important step in the growth of the movement. These two groups had been bitter rivals but joined forces against the perceived secularization of American culture. [Link] (_URL_1_)\n\nConversely, US support of Israel can be traced to its inception in 1948. American success and Jewish business are very firmly linked, and as a result America has thoroughly thrown its support behind Israel-- although this has waned in recent years because of Netanyahu's more aggressive settlement policies. Either way, you don't throw a 70 year alliance under the table because some people don't like your policies. \n\nWhat does the US get out of its relationship with Israel? The continued support of one of its most eminent and financially stable minorities, plus the support of other Western nations (namely the UK) who also have sizeable Jewish populations and a special relationship with Israel.\n\nSo the second half of your question: the US relationship with other states.\n\nAfter 9/11, people constructed the US relationship with Arab states in the Middle East far differently than it actually was. The US and Saudi had an incredibly fruitful relationship for decades, based largely in oil spending. When it was revealed that the 9/11 attackers were largely Saudi, there was, of course, a massive backlash-- but the USA never went to war with Saudi, because the business was too good and the extremism was far too easy to pin on other countries with less authoritarian governments (Afghanistan) or more openly fascist ones (Iraq.) Public disapproval of Muslim countries, paired with the discovery of oil in Canada in massive amounts, meant that the US pulled back from Saudi.\n\nWhat are the other countries in the region to deal with? Well, the USA has attempted to ally itself with the rising stars of the UAE and Qatar, but so far that seems to be a relatively incidental business relationship. Either way, that support will be in business and not in ideology: support for Israel isn't going anywhere.\n\nTL;DR\nJewish influence in the USA is still very significant, even if the total number of Jewish people isn't very high. As a result, support for Israel is unwavering. The USA does engage with other countries in the Middle East, but not the same way."
] |
[
" This has been asked many many times, you could just do a search. \n\nThere are large Jewish and Christian segments in the US that support Israel on moral and religious grounds. \n\nDuring the Cold War, the US supported Israel as a counter to Soviet advancement in the Middle East. \n\nThe US also supports Israel because it works a destabilizing factor in the Middle East, keeping the area off balance.",
" I don't know about the whole \"Bad PR\" because it is controversial and if you disagree, you will likely disagree strongly. I wouldn't say the US supports Israel in everything but it will defend it against any nation state that calls for it's destruction. Off the top of my head...\n\n1. During the Cold War Israel was a strategic ally for Soviet Aggression and one of the few partners we can reasonably rely on in the Middle East. (Saudia Arabia being another one). \n\n2. We get to sell off our military surplus to Israel and use them as a proxy for any of our interests in the Middle East.\n\n3. We share common enemies. It is at least more relateable to us that both our enemies try to blow us up using suicide bombers or terrorist attacks.\n\n4. US generally wants peace for the Palestinian situation but from my reading, Palestinians are generally unwilling to negotiate for anything less then the full restoration (lands included) of the Palestinan state. With many calling for the destruction of Israel (our ally) itself. 3 chances at statehood and still holding out for a better deal. How do you work with that?\n\n5. No other partners in the Middle East/Northern Africa(Jordon, Syria, Lebanon, Sudan, Libiya, Yemen) really offers us much in strategic value. The ones that do (UAE, Egypt, Turkey) seem willing to discuss business over destruction of Israel. With the Sunni uprising in ISIS, we may actually have stronger allies in Iraq/Iran without changing our position in Israel.\n\nIn short, Israel just makes sense from a strategic and economic perspective. The \"Bad PR\" would probably continue regardless of our partnership with Israel and we wouldn't really gain much in the Middle East for it."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How my brain decides where to put my hand to catch a ball, for example.
|
[
" You have a sense called [proprioception](_URL_0_) that your brain uses to determine the location of all the parts of your body. Through the trial and error of you growing up and developing your brain learns to use this sense to determine exactly where to place your hand to intersect the balls trajectory."
] |
[
" A lot of it is practice. Your eyes figure out the distance and your body figures out the object being thrown. Your brain considers the situation and knows how your body works. If you have trained yourself well you can do it without thinking about it too much. \n\nI used to practice half court basketball shots for fun. It was great to be able to sink one quickly and easily from that distance and psych out people who wanted to play against me. I was away from being able to practice for a while and spent some time lifting weights and manual labor. When I tried to sink the ball I kept throwing way too far because my body's abilities increased and it took a while for my brain to adjust. I shifted to 3/4 and full court shots for a while too.",
" Every time you shoot a basketball, your mind keeps track of how hard you threw it, at what angle, and from what distance. Now, if you only throw a basketball at a hoop only tens of times, you wouldn't really have a great accuracy with making it. However, if you practice consistently, your body begins to make slight changes every time you shoot - \"oh, you're shooting from a foot further out this time, let's give more force on the ball\". With enough repetitions, your body and its muscles have what is called \"muscle memory\", where your brain and muscles are on the same page. Thus, you can be given a basketball from say 10 meters out, and you will have a higher than average chance to make it. However - change one small thing, like moving the hoop from 10 feet down to 8 feet, and it will take some time adjusting to the new set up. [Destin from SmarterEveryDay](_URL_0_) has a great video showing how your mind compensates and is very neuroplastic in how it adapts to new situations even if they are completely opposite from normal."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why does plaque build up so much faster on the bottom set of incisors vs the top set of incisors?
|
[
" Also you have a salivary glands by your bottom set, and saliva brings with it the calcium and phosphate deposits that it leaves on the teeth."
] |
[
" They move through the gums slower because they are longer and have less room to emerge than the other teeth (evolution has deemed them unnecessary and is slowly phasing them out) which is why they are so painful for most people. But they've always been there, lurking beneath the surface, waiting to fuck your day up.",
" Because you move your lower jaw and the bite on the bottom part goes \"deeper\" than your upper bite."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
The United States Courts-Martial system?
|
[
" Service members can be given a civilian trial for breaking civilian laws assuming that a civilian authority chooses to prosecute them. Courts-martial are crimes prosecuted by military authority for infractions of the UCMJ. In many cases there is an overlap of the UCMJ and civilian law, in which case a service member can be tried by either a civilian court or a military court, and in some cases by both. The UCMJ also provides for many of the same protections that an accused would receive under the constitution.\n\nThere are three types of courts-martial and they are separated by the type of crime they deal with, the level of officer that presides over them, and the sentence they are allowed to give, among other things.\n\n**Summary courts-martial** deal with relatively minor infractions, analogous to misdemeanors, and if the accused is found guilty they can reduce a persons rank and confine them for up to a month. Also, summary courts-martial are only used for enlisted personel, the accused must agree to the summary court-martial, and they are not entitled to legal consul, but may retain their own and in practice are sometimes provided one.\n\n**Special courts-martial** are more akin to what you would think of as a trial. Sometimes they are presided over by a single judge and other times they have a jury decide the case. Conviction at a special court-martial can result in reduction in rank, forfeiture of pay, and confinement for up to a year. If someone refuses a summary court-martial, they are then generally tried under a special court-martial, and in this case they are entitled to legal consul.\n\n**General courts-martial** are the highest level of court-martial and deal with more serious crimes. Under a general court-martial an accused that is found guilty can be sentenced to life imprisonment or death if the crime warrants it, although general courts-martial deal with many crimes that do not allow for capital punishment. \n\nEdit: Also, the vast majority of infractions of the UCMJ are not tried by courts-martial, but rather through non-judicial punishment. NJP is generally presided over by the accused's commanding officer, and the CO reviews the case and issues a punishment accordingly. The punishment can include reduction in rank, forfeiture of half pay for two months, and restriction with or without labor. Like in a summary court-martial, the accused has to \"consent\" to NJP and can, if they choose, request a court-martial as an alternative."
] |
[
" Maybe I missed it but no one seems to have mentioned LOAC (low-ack) or Law of Armed Conflict which is the answer to your question at least from the US perspective. This is the set of rules for war that all US military personnel must follow. These rules come from various sources--the Geneva Convention for instance. Violation of LOAC by US military personnel can be grounds for court martial under the Uniform Code of Military Justice or an international military tribunal. You can read more about it [here](_URL_19_).",
" The United States [Army](_URL_4_) is the largest fighting force in personnel among the military uniformed services. Its primary mission is land based military operations. Being the largest fighting force also requires a lot of support and sustainment, so the Army has medical service, logistical and financial support Soldiers assisting units and operations.\n\nThe United States [Marine Corps](_URL_1_) is a specialized fighting force with a focus on expedient assault from naval vessels into land territory. The Marines have expanded their roles in combat over the years, however the mainstay of the Corps is special combat tactics in their specific trained environment.\n\nThe United States [Navy](_URL_3_) primary mission is naval combat and patrolling the free movement of United States vessels among the oceans. The Navy also maintains a large aviation wing for air combat over water.\n\nThe United States [Air Force](_URL_2_) is the primary air combat and patrol specialists. The Air Force has also expanded its capabilities into cyberspace and trains Soldiers in electronic warfare (other branches train in this as well but they do it best).\n\nThe United States [Coast Guard](_URL_0_) patrols the coasts of America and enforces maritime law. Keep in mind that America is bordered by two oceans and the Gulf of Mexico.\nEach branch of service can overlap into other branches, however this is their primary mission or responsibility to the citizenry.\n\n**TL;DR**\n\n**Army** - Land combat experts\n\n**Marine Corps** - Amphibious assault and shore operations experts\n\n**Navy** - Oceanic combat experts\n\n**Air Force** - Air combat experts\n\n**Coast Guard** - Maritime security forces"
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why do Guitar strings go out of tune Sharp, and not Flat?
|
[
" Your strings have gained tension due to the change in temperature and humidity causing the wood of your guitar to expand and contract. Metal strings don't expand or contract enough to cause detectable tuning issues alone. The wood of your guitar, however, does. The truss rod does the best job it can for keeping your neck at the right angle relative to the body, but it's not perfect. A slight movement of the neck backwards (towards the z axis relative to the body of the guitar) will cause your strings to go sharp enough for your ear to discern. You can test further this by playing open strings and pushing on the headstock in different directions perpendicular to the body of the guitar--just don't push too hard. As relative humidity changes, the wood of the body and neck of a guitar will expand and contract in two ways: tangentially and radially. Tangential movement lies parallel to the growth rings of the wood while radial movement is perpendicular across the growth rings. Another thing to consider is that different species of wood are more hygroscopic than others. This simply means that one species, take Maple with a radial growth coefficient of 0.00353 for example, will absorb more water--and thus move more--than another species like Cherry that has a lower radial growth coefficient of 0.00248. So, while the neck of your guitar gains or looses moisture, the wood will expand and contract relative to one of the two directions I explained earlier. This movement in either direction can very well be enough to cause more tension on the strings, thus bending them sharp."
] |
[
" When you say the band tunes down, I read this as guitar and bass players tuning down a half or whole step. As a guitar player I can tell you that if open (non fretted) strings or chords are used in a song, it sounds much better to tune down rather than transpose to another spot on the neck. Technically you CAN play the new lower chords at different spots on the neck but they just sound different. Open chords and strings sustain more and in rock music tend to have more growl and edge.",
" Because they all are randomly out of tune, but just slightly, so they add up around the proper notes.\n\nOn average you get a sound that is more intense around the right notes and their harmonics (which makes it sound non-dissonant), and the out of tune sounds just becomes a bunch of overtones making the sound a richer and more complex timbre.\n\n[See this old comment I made](_URL_0_) for some technical details and visuals."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How does vinegar breakdown mold/bacteria buildup
|
[
" Due to its pH of 2.0 and the acetic acid content, vinegar is an inhospitable environment for many microorganisms. Also, the high acidity level of it helps loosen mineral deposits, such as lime and rust, and dissolve soap scum due to their alkaline nature"
] |
[
" Bacteria and mold (fungus) grows on it. Using milk as an example, there's bacteria in milk and more in the air. Keeping milk refrigerated slows down the rate of bacterial growth. If you leave it out, suddenly the milk is a temperature that bacteria trives in, so they have a grand old time consuming the milk, 'pooping' in it, and reproducing to make more bacteria to eat and poop and reproduce and eat and poop...\n\nWant a glass of milk?",
" From what I understand, this is because bacteria has built up in the air vents. Condensation can build up in the air vents as the air conditioner is running and cause bacteria/mildew to form. There are certain products (some even recommend Lysol) that you can spray into the air intake to kill the bacteria and prevent this from happening. Some also recommend that you stop using the ac 5 min before turning off the car so it has time to dry."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
How do computers or cell phones know which signals they are looking for?
|
[
" The first step is the phone's RF receiver uses lots of filters to get rid of all the carrier waves that aren't the right frequency. Each phone company uses a different set of frequencies so this also filters out all the waves from the other companies as well.\n\nAfter that it gets way more complicated. In essence the device receives lots of data but uses some scheme to figure out which part of the data is meant for it. Some of that is done by synchronizing with the data transmissions and only listening to the signal at specific times. Some of it is done by decoding part of the data and checking the ID. If the ID matches then it decodes the rest of the data. In all these methods there are layers of security measures to prevent devices from getting the data that is not meant for them. Though it's pretty commonly known that law enforcement can gain ready access to the data in the cell signals.\n\nThis is a very broad explanation, as the details of his this work get super technical super fast"
] |
[
" So... Inductive loops, video and microwaves can all be used to\"sense\". Signal timings are based on the speed of the corridor, the amountof traffic on each street and turning in different directions, and sometimes on nearby signals of they are coordinated. Basically, the sensors tell the computer what is going on, as well as other field gathered data, and the computer runs through some if-then statements created by an engineer to try and make thetimings as efficient as possible.",
" The lock on system sends out a frequency wave that is picked up by an antenna that's main job is to Interpret that signal and sound off a warning in the cockpit.\n\n\n\n\n\nBut guys, since this post blew up, and somehow my post is on top, I just feel I need to tell everyone I'm not an avionic tech. Just an airframe & powerplant guy with VERY basic knowledge of the warning systems, and specifically hands on with only the f-16. Block 40 and 42 models.\n\n\n\n\nu/miori1230 replied with _URL_0_'s not just frequency that the antenna interprets. It also looks at how long the pulses, and how often those pulses occur. Some signals are continuous wave, so their pulses go on forever. The combination of frequency, pulse width, and pulse repetition interval help the antenna narrow down what it is that's causing the signal. Sometimes thats enough to figure it out exactly, but a lot of times it needs more information to resolve ambiguities.\nIf a missile has locked onto an aircraft, the signal from the missile will be focused directly on the plane and the plane will always be able to see the signal. If it's a navigation radar, it's probably rotating (think of those radars on the top of small boats or at the airport). That's just one more way to narrow down the range of possibilities.\nAs someone else mentioned, the F-35 and a lot of newer radars use agile frequencies so the plane can't really figure out that there's a signal there to see. A plane flying high above the earth will naturally see all kinds of stray radar pulses, most of which it doesn't care about. Those new radars are random enough and use so few pulses that it appears as though they're just part of the background noise."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Why can tv companies stop clips from shows being on YouTube but YouTube content can be on TV shows without any issue
|
[
" The studio that produces the TV show owns the copyright to it, and has the money to hire lawyers to enforce those copyrights.\n\nYouTube doesn't own the videos you see, those belong to the people who make them. If your funny cat video makes it on TV, you are not as likely to hire a lawyer. In fact, there is a good chance the TV show already contacted you and got permission."
] |
[
" It's not about the effectiveness of Youtube advertising so much as the cost. Advertising revenues from television pay out much, much better than they do for Youtube.\n\nBy keeping shows off Youtube, they can try to drive viewers to watch those shows on television, boosting their ratings (and therefore total revenue).",
" It's not laziness, Wikipedia doesn't want to worry about YouTube changing things or pulling down content. They also don't want to deal with potential copyright infringement claims. Legal or not those claims are a pain in the butt and can ruin a site's reputation. Disney is notorious for enforcing copyright and nobody really wants to fight them on it."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Isn't placebo in clinical trials extremely dangerous ?
|
[
" Tyically, they don't use a placebo in most modern clinical trials. What they use is 'Standard Care'. The goal is to see if a new drug or treatment is BETTER that the current standard care.\n\nSo for something like a cancer treatment, they compare people doing what is currently acceptable to the new treatment and see which one is better.",
" Registering for a drug trial where there's a chance you'll get placebo is usually a last resort. That is, other treatments aren't working. It seems to me that testing an experimental drug is more dangerous than sugar pills (placebo) but at that point, nothing else is working for the patient.\n\nIt doesn't need to undergo new trials in each country. Most countries will keep a list of other countries with trial methods they accept. In effect, they say \"we would have run the same trial anyway, so if Country X accepts it, we will too\"."
] |
[
" When doing placebo trials, the Control Group is given the placebo, a harmless sugar pill, and told it is the drug. If a larger number of people in the Drug Group become affected by the drug than the people who simply think they are on it, then the drug is effective.\n\nIn any experiment, the Control is the group that has the least changes made to it.\n\nWhen testing a drug, they use placebos to ensure the Control Group doesn't know they are in a Control Group.",
" In many cases, they do not. A drug's possible side effects are determined by the results of clinical trials. If the clinical trial for drug X include 100 people and someone reports suicidal thoughts, that has to be listed as a side effect. That subject's suicidal thoughts weren't necessarily caused by the drug, though. Maybe they had previously experienced suicidal thoughts or they were suicidal due to concerns about the condition the drug is supposed to treat. Hell, maybe a close family member died. In fact, I believe side effects experienced by subjects given the placebo also need to be included as possible side effects. That is also why it isn't uncommon to see drugs have death listed as a possible side effect."
] |
Given a question, retrieve the highest voted answers on Reddit forum
|
eli5
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.