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1z2qtn | how was the bureau of census measuring population before sampling? | I'm currently reading about Dr Deming's early work at the Bureau of Census and it says
> many of the users of census data were willing to accept sample results, but some of the old-timers at the Bureau of the Census were opposed to the idea of sampling
I'm new to this section of history. I may guess they were measuring the whole population but I might be wrong so ELI5.
EDIT: And (how) does sampling measure the whole population since it's a limited number of examined people? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1z2qtn/eli5_how_was_the_bureau_of_census_measuring/ | {
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"The census counts every person, or at least tries to, every ten years.\n\nHe is talking about people using the data collected - some of them insisted on using everything which, before modern computers could be a monumental task."
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dh60c4 | how is airport security regulated and kept consistent around the world |
Like do all the countries agree on regulations somehow, or could you theoretically get away with something by boarding a plane with something in one country and connecting to a different country. (I’ve never flown international so idk anything) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dh60c4/eli5_how_is_airport_security_regulated_and_kept/ | {
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"No, it’s highly inconsistent from country to country.\n\nUS is the worst for sure, I hate travelling there. Its the only place they make us remove your shoes.\n\nAtm im in Nepal, and they only pass your luggage in a scanner, barely look at it, everyone pass the metal detector, everyones beeping and they dont give a fuck.",
"It is not. \n\nEvery single country sets up their own rules and regulations, as well as how they enforce these rules and regulations. There are some countries who have treaties with others that set certain requirements for flights between said countries, but these are not always well enforced."
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3rf3qu | what is the benefit of a water-cooled pc? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3rf3qu/eli5_what_is_the_benefit_of_a_watercooled_pc/ | {
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"Generally superior cooling due to both heat absorption of liquid and a lack of stale warm air in the case. \n\nAlso quieter ",
"Water cooling is more efficient, which allows the CPU and GPU to run at a higher frequency without overheating. Depending on how the cooling is set up it can also be less noisy. Last but not least it's just plain cool.",
"Water has a higher specific heat than air. Thus its able to more quickly transfer heat away from the CPU. ",
"It permits you to transport the heat away from the core at a rapid pace, to a radiator which can be much larger than any reasonable air cooled heatsink. \n\nAir cooling has made great strides with the use of heatpipes to carry heat away from the source.",
"I imagine that you've put your hand in an oven at 400 degrees or higher before to remove a pizza, lasagna, etc. You can leave your hand in the air in the oven for a few seconds before it starts to feel uncomfortable. Now try putting your hand in a liquid at 400 degrees. It's going to burn your skin within milliseconds, right? This is because liquids take heat away from (or give heat to) objects faster than gases can.\n\nThis is what computers take advantage of. If you only use a heat-sink and fan on a computer, the metal from the heat-sink has to transfer heat from itself to the surrounding air, which is inefficient. However, if a liquid replaced the air, then it's going to transfer heat much more efficiently and quicker. "
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1r7qm7 | why group mentality is so powerful | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1r7qm7/eli5_why_group_mentality_is_so_powerful/ | {
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"Human nature to belong and conform to social groups, empathy, and natural fear of exclusion.\n\nIt's kind of instinctual, that's why the weak minded are susceptible to group mentality. Case in point: Reddit."
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3q4huh | how is the milk of a cow so beneficial to humans? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3q4huh/eli5_how_is_the_milk_of_a_cow_so_beneficial_to/ | {
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"Because it contains fats, proteins, and sugars, making it a very energy-packed beverage. Now granted, if you're lactose intolerant than you don't make the necessary enzyme to make use of the sugars, lactose, and that can lead to a fair bit of intestinal distress so...there is a downside for some people.",
"It's not just cows. Milk of many mammals is as beneficial to humans (and, on a side-note, that benefit *is* debatable, and many humans are, in fact, *not* able to process it). \n\nCows are just the animal we domesticated and started using for milk in a way that is ubiquitous in Western culture. In other cultures, other animal's milk is more widespread. That includes goats, camels, even donkeys. Also remember that much of Human population is lactose-intolerant. ",
"You can get all the nutrients you get from milk from other sources that are better for you health wise, so in relative terms it's not that great for us. People first started drinking the stuff specifically because of the calcium. Back before people had well established trade routes and high tech farming technology, sources of calcium in Northern climates were rare. The main way that humans are supposed to get our calcium is from green vegetables and fish. Not having green vegetables available for a large part of the year could mean death due to calcium deficiency for those people in the North, so they ended up with an adaptation that allowed them to drink milk from other animals that could eat the greens that grew in the area. Cows can eat grass and get the calcium that way. \n\nIn reality, all the healthy things that milk gives us like calcium, protein, and essential vitamins, you can get by eating green vegetables and meat. Even for the people who do have the ability to drink milk, eating greens and meats is actually healthier than getting those same nutrients from drinking milk because there's less sugars and fats. "
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5ec1tu | why does standing on a train tire me out? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ec1tu/eli5_why_does_standing_on_a_train_tire_me_out/ | {
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"It's the same thing as being in a car for an extended period of time.\n\nWhile you aren't really making a lot of *big* movements, you are making a *very very large amount* of *tiny* movements. Every second you're adjusting, balancing, making sure things are going smoothly, watching all of the people, etc - so while you aren't physically doing a whole lot, your muscles are constantly contracting/relaxing, and your brain is constantly thinking.",
"The train shakes and sways and changes speed while you're riding. A lot of muscles are constantly acting to absorb and counter that motion and that takes energy."
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14pyjg | why is gold so expensive? | I don't see any obvious use for gold except for jewlery :/ | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/14pyjg/eli5_why_is_gold_so_expensive/ | {
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"[It is not used only for jewelry](_URL_0_), but what does it matter if it was? There is a limited amount of gold on earth. If there are a lot of people who want that gold, the price will go up. Lets say you only have ten pieces of gold, but there are a hundred people who want a piece. If you want to make money you are not just going to ask a fixed amount of dollars. You ask those people how much they want to pay for a piece of gold. ",
"_URL_0_\n\n > Gold emerged as a sort of inevitable global currency, before people even thought of it as currency. It is rare, portable, easy to identify, can easily be made into jewelry, and can be easily quantified (unlike, say, jewels or seashells, which are harder to treat as a \"substance\"). Once word got around that rich people like it, it became easy to barter with anyone, anywhere, for anything.\n\n > In the early stages, it was not really the same thing as \"money\", it was just an easy thing to barter. But it had money-like characteristics:\n\n > - If someone walked into your apple-orchard offering to trade a yellow rock for apples, you might look at them a little funny. What use does an apple-grower have for a yellow rock?\n\n > - But if you know that rich people in town covet this soft yellow metal as something they can make jewelry out of, then you might be happy to trade apples for it. \n\n > - Once *everyone* knows that rich people will trade for this stuff, it becomes something like actual currency: neither the hunter, the shoemaker, nor the fisherman in town has much use for it, but because they know they can redeem it for the stuff they *do* want and need, it becomes a sort of transferable IOU that can be redeemed anywhere, i.e., money. \n",
"1) There's not a lot of it. 2) People like the way it looks. 3) When 1 & 2 are true (limited supply and high demand) there is high value for something.",
"by actions taken over hundreds of years of history, societies have decided by fiat that gold is a reliable long-term store of wealth.",
"The reason that gold is so expensive is because gold has been expensive for a long time, and people want gold to remain expensive, so that the wealth invested in gold will remain. The value in gold is purely a social construct, and nothing more.",
"Because it has certain properties, many mentioned here, that would make it the default medium of exchange; people are valuing it at its current level because of all the debt (which will need money to be created in the future in order to pay) and money that has been created worldwide.",
"Gold is rare and cannot be cheaply or easily manufactured. It's compact and can be stored easily. It won't rust, rot or decay when stored in a safe place. It's also considered beautiful (hence the jewelry thing). Something rare, beautiful, resilient and _small_ (compared to it's relative value) makes it an excellent store of value or wealth.\n\nGold _does_ have some industrial uses but it's value derives mainly because it is _universally recognized_ as a store of wealth. If everybody suddenly decided it was useless, it would have little or no value."
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fwgbt2 | how do options and shorts work for investments? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fwgbt2/eli5_how_do_options_and_shorts_work_for/ | {
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"For shorts, its better to think about what you're expecting to happen when you do it than how its actually executed in the market (which is more complicated, but ultimately unimportant to you, the trader).\n\nWhen you buy a stock, the *only* reason to buy it is that in the future you expect it to be higher than when you bought it. This is being \"long\".\n\nWhen you short a stock, the *only* reason you \"buy\" it is that you think the stock will be lower in the future.\n\nYour broker doesn't give a shit what you trade, they just facilitate the trade and take a commission (this is a bit untrue, but for these purpose its fine). When you short a stock, you potentially have a chance to lose more money than you have though, so they require these accounts to have some extra money to cover the losses in case that happens.",
" > Why do platforms allow shorting, doesn’t it make them earn less if the stock drops?\n\nMake who earn less?\n\nShort selling is a simple principle, you borrow stock from someone else who is holding it, sell it on the market, and then return it to them at some point in the future. If stock price goes down, you sell high then buy low, pocket the difference and return the share. If stock price goes up, you choose when you have to buy the shares back to give back to the borrower, here you sell low buy high, eating the loss. With brokers this is easier, they have a vast pool of people who hold shares that they can borrow from, as long as all of them don't sell at the same time there is always someone you can keep borrowing from.\n\nThe broker doesn't or risk anything here as long as you show the ability to buy back the share (posting sufficient collateral, if you don't then the broker will loan you money with interest which limits their risk), the person from who you borrowed generally loses (if they sell) but that was the risk they agreed to when they bought the share.\n\nOptions are a different thing than short selling but can accomplish a similar purpose. \n\nA call gives you the right to buy 1 shares at any point until some future expiration date at the strike price. A put gives you the right to sell 1 shares at any point until some future expiration date at a strike price. Do note that options are only sold in batches of 100. \n\nSay I buy a call for company A (whose share price is 10 dollars), with a strike price of 11 dollars and expiration date of next friday, costs me 1 dollar. If A's share price increases to 12 dollars, at expiration I just broke even, but if it rises to 13, I can buy a share at 11 dollars using the contract and sell on the market for 13, pocketing 2 dollars minus the 1 dollar I paid for the contract initially. If it stays stagnant at 10 dollars, or in general goes to less than 11 dollars, at expiration, it doesn't make sense for me to exercise this option so I don't it expires worthless and I lost the dollar I put in. \n\nPuts work similarly in the opposite way, think about how this works with selling. Puts are a bet that the stock goes down, try to apply the same logic as a call but with selling at a price instead of buying.",
"The idealized idea and general business model of a platform is indifferent to the types of position you take ie long or short because they function as a meeting place between buyer and seller. They make money off the volume of trade and (mostly) aren't the counterparty to your trade - ie one person going short means someone else goes long. They are concerned that the traders are \"reliable\" - ie that you fill your position and not run away with or have insufficient assets which is a higher risk to the platform in short positions.\n\nThat said, shorting is still not allowed by some governments (ie the stock exchange). Some feel that increases short term volatility and is a sort of \"bet on failure\". Others say that shorting delivers the right \"signal\" and that it allows for better price discovery - ie stocks prices reflect the market sentiment better. \n\nOptions are standardized contracts (ie legal agreement) between two parties to agree to trade (buy and sell) some stock in the future at a fixed price with an option (ie the right) to nullify the trade given to one party. The other party must complete the trade if the holder of this option so chooses. This \"option\" is clearly valuable and represents the price of that option.\n\nThe idea of the option is straightforward but the terminology used and liability involved is confusing. A put option is a contract where the option belongs to the seller of the stock (\"ie right to sell this stock on this date at this price\"). A call option is a contract where the option belongs to the buyer of the stock (\"ie right to buy this stock on this date at this price\").\n\nNow each type of option (put or call) contract has two parties. (again sometimes confusingly, the term buyer and seller are used again). The person who obtains the right is called the buyer of the option. The person who gives up the right is called the seller of the option. The reason for this terminology is the buyer of the option has to pay the seller because this \"right to buy/sell\" has value. \n\nBecause these option contracts are standardized (100 shares typically) and their value changes over time, there is a secondary market for these contracts - there are people who want buy and sell existing options contracts. And this is what is usually seen on trading platforms.\n\nExample: \n\n1) AAPL $200 Put June 2020. This is a contract that gives the right to sell 100 Apple shares at the fixed price of $200 on June 2020. \n\n2) AAPL $200 Put August 2020. This is a contract that gives the right to sell 100 Apple shares at the fixed price of $200 on August 2020. \n\n2) AAPL $200 Call June 2020. This is a contract that gives the right to BUY 100 Apple shares at the fixed price of $200 on June 2020. \n\nThe $200 is called the exercise or strike price, and the date is when the option contract expires (ie must be completed or nullified). To make matters worse, there are standardized so called \"American style\" or \"European style\" options contracts which give different rights. \n\nThere are MANY MANY moving parts to options - strike price, option expiry dates, puts or calls, the price of the actual shares (in the example Apple), the price of the option contract. These option contracts are time limited, highly volatile and (for some stocks) thinly traded. These are all risks that the traders in options must appreciate.\n\nLink to useful resource:\n\n [_URL_0_](_URL_0_) \n\nCheers!"
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1sxoss | can someone explain to me the pros and cons of capitalism? | I feel I know a bit of both, but not nearly anything when I really think about it. Help? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1sxoss/can_someone_explain_to_me_the_pros_and_cons_of/ | {
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"As far as economic history goes, there simply isn't a better set of institutions than capitalism to generate technological growth.\n\nCons: inequality - though this can be abated with a welfare state.",
"Capitalism: An economic system under which capital is controlled by private individuals.\n\nCapital: Productive property such as factories, farms, financial institutions, or other systems which create wealth.\n\nPros: In theory, it allocates capital to the areas in society where they are most useful. For instance, let's suppose Mr. White, Mr. Green, and Ms. Brown all own factories making T-Shirts. Ms. Brown finds a cheaper way to put the design on T-shirts, thus, she can make more of them while spending less money. Because she's spending less money, she is able to expand the factory, so more T-Shirts will be made in the more efficient way, benefiting society.\n\nCons: A lot of the money that goes to capitalists doesn't make its way down to the rest of society, and ends up not benefiting society in any particular way. For instance, after a few months or two, Ms. Brown is making enough money that she not only expands her factory, but also buys Mr. White's factory. Now she's making twice as much money (even though she isn't doing twice as much work as she was before). Now, most of her money is going to pay for luxuries and more capital. This isn't benefiting society, since it's silly to produce extravagant luxuries for the few when there are still people struggling to get things they need. Furthermore, Mr. Green has long since adopted the new way of making T-Shirts, so it no longer really benefits society that Ms. Brown is expanding her factories, because factories owned by her are no longer any more efficient than factories owned by anyone else. In fact, Ms. Brown doesn't even manage most of the factories anymore; she pays other people to do that. So in the end, the only one who has benefited from Ms. Brown having so much capital is Ms. Brown herself."
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1t1wve | how does apple own the beatles? | I just saw the movie Jobs and have been obsessed with apple and Steve Jobs lately.. How does Apple own the rights to the Beatles when Paul McCartney is still alive? /How does all of that royalty stuff work? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1t1wve/eli5_how_does_apple_own_the_beatles/ | {
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"Apple Inc, the computer/device company, is different from Apple Records/Apple Corps Ltd, which is the record label created by the Beatles. Apple Inc doesn't own the rights to the Beatles music.",
"[The Beatles sold the rights to their catalog of music back in the 1960s.](_URL_1_) It's been owned by many people, most famously by Michael Jackson, who made almost as much money on Beatles royalties as on his own music.\n\nI don't know if Apple Computer has any ownership in Beatles music, but you might be confused by [Apple Records](_URL_0_). Long before Steve Jobs was in business, The Beatles named their record company Apple. There was actually [a lawsuit between the computer company and the record label, because of conflicting trademarks.](_URL_2_)",
"Actually, Apple Records IS owned by McCartney and Ringo and the estates of Lennon and Harrison.\n\nInteresting point to add:\nYou may remember that it was a big deal (well kind of) when iTunes started carrying the Beatles' music. Why the delay?\nThere was a lawsuit (as /u/PLJVYF stated) between the two in which the judge basically said that it was okay for the two companies to have the same name because the computer and music markets were completely separate. \nWell, as Apple computers started gradually including music as part of its market, it had regular legal clashes with Apple Records and they weren't able to reach an agreement to sell the Beatles' music on iTunes. Too much animosity between the two. It did eventually get cleared up though, and the Beatles were on iTunes in 2010."
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5vle6l | if in the vacuum of space there are no exterior forces acing on a spacecraft, why can't we continuously speed up the craft to light speed with constant thrust? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5vle6l/eli5_if_in_the_vacuum_of_space_there_are_no/ | {
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"It takes more and more energy to constantly accelerate a spacecraft. This means that as you approach C the amount of energy that you need to go faster approaches infinity. Sadly humans do not have access to infinite energy so we can never actually reach C.",
"Because of relativity, from your point of view on the ship it may seem like you are always accelerating but from the point of view of someone back on Earth, you will never reach the speed of light. From their perspective, the closer you get to the speed of light the more slowly you would seem to age, the more your length would contract in the direction you are moving and the more your mass would increase. Theoretically, your mass would become infinite if you could reach the speed of light. Since the amount of energy needed accelerate an object is proportional to its mass, you would need an infinite amount of energy to accelerate up to the speed of light.",
"The main major problem is it would take a massive amount of energy (i.e. fuel) to be able to produce enough overall thrust to even get *close* to the speed of light (ignoring relativistic implications of doing this). That fuel has to somehow be contained in a single spacecraft and that massive spacecraft has to be launched from Earth while also hauling that massive payload.\n\n > Why not just build the spaceship *in* space?\n\nIt would still require astronomical resources to ferry enough building materials, crew, and fuel using smaller crafts spread over hundreds of trips up to the theoretical shipyard. \n\nThe sheer amount of time it would take to accomplish the feat of building and launching such a spacecraft using existing technologies and fuel sources would probably equal the amount of time it will take humanity to discover new technologies that can accomplish the same thing cheaper and faster."
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ctl2kg | when cops and dea agents perform undercover drugs busts where do they obtain said drugs? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ctl2kg/eli5_when_cops_and_dea_agents_perform_undercover/ | {
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"I think most of the time they act as the buyers, not the sellers. They are trying to work their way UP the ladder, not down, so they want the dealers, not the end users. \n\nSo they just make multiple buys from a small dealer, then bust him, and try to flip him to be a double agent in exchange for less jail time. Then they try to get him to introduce them to the next step up the ladder and do some bigger buys from him, then bust him and try to flip him also. \n\nThen they just repeat this process as high as they can go, but the higher they go and the less productive the undercover operation is, as it takes much longer to gain trust, and get to the real kingpin instead of one of his flunkies or lieutenants, plus the buy quantity needs to keep escalating and it's hard to tell your boss down at the cop station, \"Hey, I need a million bucks to buy some drugs\" so there is really only so high they can go before it becomes completely unproductive.",
"I know of a movie/film prop house in Atlanta that makes fake drugs specifically for drug busts. Also film. They also specialize in high quality fake money for film which involved years of talks with the Secret Service to figure out what could be allowed. I guess that's part of where the connections were made for the fake drug supply stuff.",
"While the other comments here are are accurate, the DEA does keep a small quantity of drugs on hand if there is a need to have _actual_ drugs used in sting operations.\n\nThese drugs are obtained from other drug busts, and are simply not destroyed after the trial (as is customary for drugs seized as evidence)."
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4qy10k | what happens to clothing that isn't sold? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4qy10k/eli5_what_happens_to_clothing_that_isnt_sold/ | {
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"What you're asking about is the retail chain. For most products, it works like this:\n\nManufacturer makes a product, and markets it to retailers, who place orders in various quantities. They ship the orders, and the retailers sell it in line with their contract with the manufacturer. Using your example, Levi doesn't want to compete with itself or have the price fall so low it causes perceived value issues, so they may have a minimum price the jeans can be sold for.\n\nAfter a certain point, the unsold merchandise will go through a series of price reductions via sales, promotions, bogos, and ultimately end up on clearance.\n\nThe merchandise remaining after the clearance sale will be sent to the retailers distribution centers and bundled into lots. These lots are sold to discount outlets. For clothes, that would be places like Marshall's, Kohl's, TJ Maxx, etc.\n\nThey go through the same price reduction process as before, only becoming cheaper still. These places do hold on to merchandise for a considerable amount of time. You can find some relics at Big Lots, for example.\n\nIf the merchandise is still sitting unsold, it often ends up being put back in lots and re-auctioned to the bottom feeders of the retail chain - flea marketeers, eBay and Amazon wanna be moguls, etc.\n\nAt that point, the merchandise that doesn't sell is either so severely discounted, you are literally only paying for the shipping and storage, or it is finally liquidated via donation for tax purposes.\n\nOr, you fill a warehouse with it, wait a respectable amount of time, and light a match.",
"It depends there are a few companies that will dependent on the manufacturer's (or the company that had them made for them) wishes will either:\n\n- destroy them\n- remove all identifing features and sell them in some country where the manufacturer is not present in the market.\n- simply sell them in some far away country\n- or simply sell them off to clearence stores / dollar stores or similar",
"Something funny to think about is that they print \"Superbowl Champion\" shirts for both teams so somewhere in Africa, there are a bunch of kids running around in Seattle 2015 shirts.",
"I'm surprised there isn't more mention here about the companies that do just destroy and throw away the unsold clothes, it's actually a pretty large problem. Just so a quick Google, there's been a lot of flack about this lately.\n_URL_0_"
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7lc8hh | how is a single injection of a drug able to provide months of therapy? | My wife is getting a single shot of a drug that will stop her production of estrogen for a full three months. I read about "once a year" injections that can provide months of relief for various conditions. How can a single dose of a medication remain metabolically active for months at a time? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7lc8hh/eli5_how_is_a_single_injection_of_a_drug_able_to/ | {
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"Esterification of an injectable steroid basically accomplishes one thing, it slows the release of the parent steroid from the site of injection. \nThis happens because the ester will notably lower the water solubility of the steroid, and increase its lipid (fat) solubility. This will cause the drug to form a deposit in the muscle tissue, from which it will slowly enter into circulation as it is picked up in small quantities by the blood. Generally, the longer the ester chain, the lower the water solubility of the compound, and the longer it will take to for the full dosage to reach general circulation."
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4dcac6 | how quartz crystal resonators work? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4dcac6/eli5_how_quartz_crystal_resonators_work/ | {
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"They rely on a piezo crystal. These crystals have the useful property that they generate a voltage if you squeeze them, and expand or contract if you apply a voltage. They are commonly used in lighters (squeezing them generates a high voltage, which causes a spark), speakers and ultra sound transducers(a rapidly oscillating voltage contracts and expands the crystal) and kitchen scales (putting a weight on them generates a voltage).\n\nAs a resonator, the crystal is tuned like a musical instrument to oscillate at a certain frequency, and combined with a small amplifying circuit. If you turn it on, it starts oscillating at a precise frequency, and never stops. Imagine it like a tuning fork, only that it never stops humming as long as you apply a voltage.",
"Quartz is Piezo Electrical. Which means if it moves it generates power. Or if power passes though it, it moves.\n\nThe Quartz Crystal is placed in contact with metal wall. Power passes though, Quartz moves, power is cut off, Quartz moves back, power is back on. As long as the circuit has power it'll produce a predictable On/Off/On/Off hundreds of thousands time per second forever. ",
"Someone will be able to explain it better, however it basically oscillates at a specific frequency, if we apply a specific voltage. So, if we do apply that known voltage, we can count up its 'vibrations' so to speak, and we can use that to accurately measure time.",
"There is a great Air Force training video that explains it like you're five. \n\n_URL_0_"
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4szktg | how does the 100 year old light bulb work? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4szktg/eli5_how_does_the_100_year_old_light_bulb_work/ | {
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"I believe you're talking about the firehouse lightbulb that is 100 years old.\n\nThe answer is a combination of several things- the bulb has been fairly gently used, the power that it running it is lower than standard, the bulb itself is of a sturdier design than its modern replacements would be, and, IIRC, the bulb is in a dangling wire fixture, which provides some protection against vibrations from nearby traffic, activity in the building, or earthquakes.",
"Lightbulbs work by running current through a wire, making that wire get white-hot and using that whiteness as light. The hotter a lightbulb is, the whiter, and brighter, the light. The thinner the filament, the more light you get for a given amount of electrical power. Therefore, an efficient lightbulb needs thin wires. Thin wires break easily. Long-living lightbulbs are less efficient, dim, reddish and therefore have many drawbacks over conventional 1000 hour bulbs. But it makes for some nice headlines.",
"It's actually nowhere near as exceptional as you think. A huge proportion of the wear on light bulb filaments is to to thermal expansion and contraction from being turned on/off (this is why bulbs only ever to fail when you first turn them on). These very old bulbs are bulbs that have been left on continuously, so they don't get that wear: they just sit there, at a steady temperature, not being stressed in any way, so they don't fail. "
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e7jnch | how does a fast charging plug charge faster when the socket has the same output when there's a regular plug? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/e7jnch/eli5_how_does_a_fast_charging_plug_charge_faster/ | {
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"The \"fast charge\" socket **does not** have the same output.\n\nThe voltage is the same, but the current available at that voltage is higher. This must be taken into account when choosing cables and connectors."
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3ap076 | after their extinction, why did dinosaur type creatures not evolve all over again? | After the dinosaurs suffered the extinction event and life had to 'start over' to a degree, why didn't creatures similar to them evolve all over again?
If life had evolved as such to create all the dinosaurs creatures and they were seemingly wiped out by a disaster (rather than simply not being up to it as a species) then why didn't evolution see a repeat of that 'type' of species again?
Why did life find a different way? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ap076/eli5_after_their_extinction_why_did_dinosaur_type/ | {
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"There are infinite forms for life to try. There is no trajectory of evolution except the historical lineage. Since the non-avian dinos were erased, there was no evolutionary history to build on. ",
"Evolution creates species that do better in there current environment than there predecessors. Dinosaurs or creatures like them didn't 're-evolve' because they wouldn't have survived in the post extinction environment better than the surviving species of there family/group.",
"Well, first of all, Dinosaurs never disappeared. Their descendants still roam this earth and are one of the most successful and widely spread types of animals on the planet: birds. \n\nWhatever species evolves after a massive extinction event like that is really down to a lot of luck and timing (having the right traits at the right time), what sort of competition is out there for those species, what kind of environment those species are evolving in, and none of those things are static. The ancestors of dinosaurs (archosaurs) had the right luck, the right timing, the right traits for dealing with their competition, and the right environment to thrive in after the Permian-Triassic extinction event (a mass extinction even bigger than the Cretaceous-Paleogene extinction event) which had wiped out *a lot* of the species competing with them for resources. But just because they were able to do that once, doesn't mean all those events lined up again. A lot had changed. Most giant dinosaurs were unable to deal with the impact winter that followed. And the smaller ones that could deal with that winter were either birds/bird-like (which, again, have turned into a hugely popular group) or were outcompeted by early mammals (which are actually descendants of synapsids, the group Dinosaurs once outcompeted after the Permian-Triassic extinction event). ",
"Actually many Mammals and Birds fill niches vacated by the Non-Avian Dinosaurs. Convergent Evolution seems to be a vastly under appreciated concept. ",
"The ecological niches formerly occupied by dinosaurs were taken over by the creatures that survived the mass extinction. So now instead of big dinosaur carnivores like t-rex, we have big mammalian carnivores like lions, tigers, polar bears, killer whales, and fish like great white and bull sharks.\n\nIf all mammals became extinct tomorrow, but amphibians survived, hundreds of millions of years from now there would probably be big amphibian carnivores and big herbivores.",
"Evolution takes place in an environment; different organisms compete to best survive (reproduce) in an environment, and it is their adaptation to it that drives evolution. \n\nThe environment of the earth after the dinoasaurs died out was different from that when they first evolved - for one thing, there were all those dead dinosaurs! That may sound silly, but that really was one of many factors that drove the evolution of the surviving species. Another major factor was the thing that wiped out the dinoaurs, the meteor impact that affected the global climate. If it was drastic enough that the living dinosaurs were wiped out, then it was drastic enough that any new evolutions that might be similar to the old dinosaurs wouldn't survive either. And there is the factor that organisms themselves are part of the environment. The dinosaurs could never evolve again because now there were other species that took their environmental niche. To regain that niche, the surviving descendants of dinosaurs had to evolve in to something different from dinosaurs (and that's what modern birds are).\n\nSimilar organisms can evolve in different places or times only if the environments are sufficiently similar. The earth is always changing, and was never similar enough to the pre-dinosaur environment, so similar species never evolved again."
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j3oo0 | programming and writing computer code (if it can be explained to a 5 year old) elim | Where to begin, how to do it, important programs and tools? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/j3oo0/programming_and_writing_computer_code_if_it_can/ | {
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"If you have a lot of time, I think a wonderful and engaging introduction is Harvard's [CS50](_URL_0_) course, and it leads you step-by-step through many of the questions you have. "
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8zaa51 | how can google get fined by eu for practically promoting their own products/brand(google search engine & android/google search engine on android devices) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8zaa51/eli5_how_can_google_get_fined_by_eu_for/ | {
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"How can they? The EU can impose a fine and refuse to let them operate in the EU until it is paid.\n\nWhy would they? Because it can be considered a breach in monopoly laws. Microsoft was indicted on the grounds of monopolization for bundling internet explorer with their OS. \n\nI may be a bit out of the loop but are you asking about what rule they might break or what rule they did break?"
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nnv0t | computer shellcode (shell code) | Please ELI5 what malicious shellcode (Shell Code) is, how it works, and how it can be avoided. Thank you. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/nnv0t/eli5_computer_shellcode_shell_code/ | {
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"If you're not a programmer, the only thing you can really do is make sure that you consistently update your software, especially when it says it's for security reasons.\n\nIf you are a programmer, you should be aware that one of the most common types of security vulnerability is a buffer overflow. What this means is that if your program is not properly checking the length of data inputted by the user, the user can write past the boundary you have allocated for that particular data and overwrite different parts of memory. This becomes an issue when the user overwrites the code segment of memory, which tells the computer which instructions to execute. If a malicious user overwrites this area of memory with his own instructions, they can be executed instead. Commonly, a user will overwrite it with \"shell code,\" which is code designed to spawn a shell. A shell is basically the command line interface by which you can control your computer (cmd most closely resembles this in Windows).",
"This may be a bit past ELI5, but I'll try:\n\nSo first, let's define the shell: a way for the user to give the computer instructions.\n\nShell code is a way of creating a shell from somewhere else that I can use. Say I'm in New York and your computer is in Los Angeles, shell code gives me a way of opening a shell so I can control your computer over the internet.\n\nHow it works: The person trying to execute shell code gives a program some bad input that gets the shell code in \"the right place\" so that it runs next. Imagine I give you a piece of paper with a list of instructions:\n\n1) Go to the grocery store\n\n2) Go to the meat counter\n\n3) Ask how much the filets cost\n\n4) Walk back home\n\n) Write down the filet cost here: \n\nNow, the guy at the meat counter says, \"Oh, I'll make it easy, hand me your paper and let me write down the price.\" But he's malicious, so he writes down the price but also writes over your old instructions, so now step 4 on your list is \"Go see the banker and do whatever he says.\" He hands you back the list, and you see step 4 and go to the banker and wait for him to tell you nefarious things to do. (So the shell code would essentially be telling you to go to the banker.)\n\nHow it can be avoided: there are various approaches, but it's kind of an arms race. Generally it amounts to either checking the amount of input -- making sure that when the guy at the meat counter writes down the cost, he doesn't try to use more room than you gave him to write -- or putting extra data around the \"walk back home\" instruction to make sure it hasn't been altered.\n\nEdit: it occurred to me that you may have meant how can you avoid it as a user, not as a programer. Like smango said, basically, your best bet is keep all of your software up to date.",
"If you're not a programmer, the only thing you can really do is make sure that you consistently update your software, especially when it says it's for security reasons.\n\nIf you are a programmer, you should be aware that one of the most common types of security vulnerability is a buffer overflow. What this means is that if your program is not properly checking the length of data inputted by the user, the user can write past the boundary you have allocated for that particular data and overwrite different parts of memory. This becomes an issue when the user overwrites the code segment of memory, which tells the computer which instructions to execute. If a malicious user overwrites this area of memory with his own instructions, they can be executed instead. Commonly, a user will overwrite it with \"shell code,\" which is code designed to spawn a shell. A shell is basically the command line interface by which you can control your computer (cmd most closely resembles this in Windows).",
"This may be a bit past ELI5, but I'll try:\n\nSo first, let's define the shell: a way for the user to give the computer instructions.\n\nShell code is a way of creating a shell from somewhere else that I can use. Say I'm in New York and your computer is in Los Angeles, shell code gives me a way of opening a shell so I can control your computer over the internet.\n\nHow it works: The person trying to execute shell code gives a program some bad input that gets the shell code in \"the right place\" so that it runs next. Imagine I give you a piece of paper with a list of instructions:\n\n1) Go to the grocery store\n\n2) Go to the meat counter\n\n3) Ask how much the filets cost\n\n4) Walk back home\n\n) Write down the filet cost here: \n\nNow, the guy at the meat counter says, \"Oh, I'll make it easy, hand me your paper and let me write down the price.\" But he's malicious, so he writes down the price but also writes over your old instructions, so now step 4 on your list is \"Go see the banker and do whatever he says.\" He hands you back the list, and you see step 4 and go to the banker and wait for him to tell you nefarious things to do. (So the shell code would essentially be telling you to go to the banker.)\n\nHow it can be avoided: there are various approaches, but it's kind of an arms race. Generally it amounts to either checking the amount of input -- making sure that when the guy at the meat counter writes down the cost, he doesn't try to use more room than you gave him to write -- or putting extra data around the \"walk back home\" instruction to make sure it hasn't been altered.\n\nEdit: it occurred to me that you may have meant how can you avoid it as a user, not as a programer. Like smango said, basically, your best bet is keep all of your software up to date."
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4smarr | how far ahead we are in achieving unified field theory ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4smarr/eli5_how_far_ahead_we_are_in_achieving_unified/ | {
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"Not very far unfortunately. Without going into the details (which I'd be crap at explaining anyway), string theory seems to be the most promising avenue. However, there seem to be virtually an infinite number of configurations of the math that leads to a consistent universe which makes it practically impossible to find the right equations that would give us the conditions for our universe. Without the math it's extremely hard to come up with experiments that would test the theory. There's also the problem of the theory being based on sizes near the Planck scale which are currently impossible for us to see. A few experiments or potential observations have been proposed which could provide evidence based on current or near future technology, but so far none have yielded any evidence.\n\nThere's also the problem that so far there is no experiment or observation proposed which could disprove the theory. For a scientific theory to even be considered a scientific theory, this is one of the most important features. (I.E. relativity could be disproved by there being no time dilation observed by clocks or observing something moving faster than light speed.) String theory so far has nothing like this after a couple of decades, and there has been debate about whether or not it should even be considered a scientific theory.\n\nThere are a couple of other possibilities being floated around, but so far they have yet to yield any results more promising than string theory."
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1sod3n | how do generic brands work and why are they cheaper than their name brand cournterparts? | I've always wondered, as a frequent consumer of generic brands, I e always wondered what was it that made it so much more cheaper than the name brands. Like, is it made with cheaper ingredients or materials or is it just the reason that its not a name brand that its cheap? How do stores get their own generic brand like Kroger or best value? Do they have their own company manufacturing the products or what? Also, I'm talking about all types of products like food, contact lens solution, medication, anything generic. Ive just been curious about it. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1sod3n/eli5_how_do_generic_brands_work_and_why_are_they/ | {
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"My roommate used to work at Kraft foods. He said when they were making the \"Brand Name\" product, everything was added to the mix. About mid day they would change to the \"Store Brand\" product, and either remove an ingredient, or use lower quality ingredients, and just change the label.",
"More often than not there is no difference other than the packaging. Most \"generic\" batteries, for example, are produced on the same line as Duracell and just have a different label.\n\nThe rest of the time they have lower quality, either in terms of ingredients, fiber quality, etc., etc.",
"Typically the main difference is the amount of marketing the company puts in. Large brands put in millions of dollars into marketing while off brand counterparts usually advertise not at all. Sometimes they may even made in the same place as brand name products but it comes down to the advertising costs.",
"I think the story for generic drugs is a little bit different than other products:\n\nTypically, the \"brands\" (non-generics) are made by companies that have patents. These patents, in the United States, last 20 years. By having this patent, a company producing the drug establishes a monopoly. As a monopoly, it has considerably more **market power** because it is able to set the price of the good without having to deal with influence from competitors.\n\nWhen the patent expires, the monopoly status is lost. Competitors enter the market and now all of the suppliers will begin to play by the rules of the free market.\n\nOften, however, the brand name remains considerably more expensive. As an example of this: Lipitor costs about $152.00 for a one-month supply, while Atorvastatin (it's generic counterpart) costs about $14.00 (Source: Costco Pharmacy). Marketing plays a role at this point; the pharmaceutical companies invest on swaying prescribers to feel their drug is better. Or, they might just work to make their drug the most recognizable. It may even be subtle: if all you know furosemide by is Lasix, you may just start writing prescriptions for Lasix. If this happens to be paid by your insurance company, then nobody will make much of a stink about it and the drug company wins.\n\nAs an aside: The active ingredients in pharmaceutical generics are required by law to be identical or bioequivalent to previously patented brand-name drugs. However, the packaging (the materials in the capsule, for example) may vary as these aren't the active ingredients. For some patients with bad reactions to generic medications, providers may opt to continue prescribing the brand-name drug.\n\n",
"The scope of your questions is pretty broad. The difference between generic and brand name is different depending on the category of product (food, prescriptions, toiletries, fashion, gas ect...)\n\nCBS has an online article that answers the question for some of the categories (_URL_0_)\n\nI can tell you that a very large manufacturer of chips also makes chips for store brands. They do this for a few reasons. First they make sure that even if you buy the cheaper store brand they still make money. Second the can control the quality of the store brand. They can (and do) make sure that inferior quality ingredients are used. (Source: I worked for this company)\n\nThe same is true for a lot of dry pasta. They are made at the same factory. \n\nIn some cases there are factories or companies that make a product exclusively for store brands. In these cases the ingredients can be very different. "
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3t2p0i | what is a runny nose supposed to accomplish? it seems so counterproductive | As soon as snot starts flowing into your nose, you're just going to sniff it back it. I've seen this reaction in every person, and even every mammal I've ever seen with a runny nose. Don't we just end up snorting all the germs back up into out internal snot chutes? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3t2p0i/eli5_what_is_a_runny_nose_supposed_to_accomplish/ | {
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"Your \"internal snot chutes\" empty into the stomach. The snot, along with anything that happens to get stuck in it, gets destroyed by stomach acid. So sniffing it back in, and then down into your throat, is the entire point."
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4d134m | how can we know the size of the observable universe of we only just escaped the solar system? | I know we didn't really leave the solar system but I can't spell. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4d134m/eli5_how_can_we_know_the_size_of_the_observable/ | {
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"We can look at galaxies outside ours, and see how far away they are (using various techniques like standard candles, a particular kind of star with known brightness) and how fast they are moving (using techniques like redshift). When we do this, we find that (almost) everything is moving away from us, but the speed they move away is proportional to the distance away they are.\n\nIf we turn time backwards we would see them coming towards us. We can use maths to work out when they would hit us. This is ~13Billion years. Because we have turned back time, we can make it go forwards again and we see a Big Bang. So know we know the age of the universe. (I am ignoring dark energy, because I don't know what it is).\n\nBecause the universe is ~13billion years old, and light is the fastest thing in the universe, the furthest we can see is things which gave of light 13 billion years ago, thirteen billion light years away.",
"You can observe something without going there.\n\nFor instance, I can observe the city across a busy ship channel. It's clearly observable. However, I would not want to swim across the ship channel to go walk around in the city. I would need my own vessel capable of safely crossing the intervening waters to allow me to get there safely.\n\nIt's the same for space. We can observe it from earth with the naked eye. Stars are part of observable space. They're not in the solar system, yet we can see them without any equipment. But to visit them we would need a vessel capable of getting there safely. The people that launched it would be long dead before it reached its destination unless we drastically extend our lifespans, or faster than light travel happens.",
"_URL_0_\n\nlight travels fast, but not infinitely fast. a very short time after the big bang light was first able to travel in straight lines relatively unobstructed. we can only see as far away from our vantage point as the light gets to us.\n\nso if the universe is 13 billion years old, you would only expect to be able to see a sphere around us with about a 13 billion light year radius. That is simple way to think about the observable universe.\n\nbut the universe is still expanding, so it is a little more larger and more complicated than that, too.\n\n",
"The more important question that has been bothering me is, how exactly do scientists have the rough measurement of the size of the un-observable universe?",
"The current top reply is incorrect. Certainly if you were to assume a static universe, then knowing the age of the universe would easily give you an estimate of the size of the observable universe, but the response neglects dark energy, which vastly underestimates the approximation.\n\nWe know space has been expanding since the big bang, and we also know that the rate of expansion is increasing. This means that an object that is, say, a billion light years from earth will emit light that will have to travel much further than one billion light years to reach our telescopes, because the distance between the object and earth has been increasing. And when we get that light, we know that that object has since traveled even further away than it was before. A few calculations reveal that objects we'd think are 13.8B light years away are actually around 46B light years away, meaning in either direction the furthest things in the observable universe are 46B light years away, giving an approximate diameter of about 93B light years. \n\nAs to address u/tikhung01's question, we have a few very, very rough ideas of how big the entire Universe is, but as of right now there is no answer. Maybe the Universe is 100B light years in diameter, maybe its 10,000B light years, and maybe it's size is infinite. That may seem a little unsatisfying, but we just don't know.",
"The diameter of the observable universe is 92 billion light years centered around us. The oldest light we can see has been travelling for a little less than 13.7 billion years but the distance which it has traveled is **now** 46 billion light years. We know this because of the redshift of the light from the furthest galaxies is redshifted more than galaxies closer to us because of the expansion of space. It's analogous to someone throwing you a ball and then running away from you. By the time you receive the ball(light) the person(galaxy) is standing much further away. "
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1mhpx8 | why in germany or the netherlands the youth unemployment rate is under 9% while in countries such as greece, spain and portugal the same rate ranges from a 40% to 60%? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1mhpx8/eli5_why_in_germany_or_the_netherlands_the_youth/ | {
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"Overall unemployment in Germany and the Netherlands is significantly lower, so without a lot of unemployed, experienced workers around, businesses have no real choice. They would either have to get into a bidding war with other businesses over older, already trained workers, or hire young people and train them themselves.\n\n\nIn Spain, Greece and Portugal, businesses have no need to take on younger, inexperienced workers because they can hire unemployed experienced workers cheaply. In addition to that, with the situation of the economy in those countries, businesses aren't expanding, so they're hiring fewer new workers to begin with. They may even be overstaffed already.",
"First of all, currently the situation in those countries with extremely high youth unemployment is exceptionally bad. For that reason alone you can expect it to be a quite a bit higher than usual.\n\nNext, you have to consider what youth unemployment actually means. It doesn't mean that 40-60% of 15-25 year olds are unemployed, but only those among this group who aren't in school, university or an apprenticeship are (i.e., it's the share of those who could take on a full time job tomorrow). So, while many among the unemployed youth indeed have already finished their professional training, the proportion of people without a learned profession (among the group relevant for those statistics) is higher than in an age group that is old enough to have a professional degree, because the ones still in training aren't counted while their peers of the same age but without professional training are. An economic crisis always hits untrained workers harder.\n\nFinally, Germany has a [different education system](_URL_0_) for vocational training. To learn a trade, apprentices split their time between trade school and (the larger part) on the job at a company. So, by the time they graduate, they've already been with a company for (typically) three years, which is more than just a foot in the door. ",
"It is often a statistical illusion (but not always).\n\nEmployment is calculated as \"number of people employed\" divided by \"ACTIVE population\" which is the population looking for a job.\nIn order to have high figure of employment (ie a low for UNemployment), you can either have a high number of people employed AND/OR a LOW active population.\n\nUnlike what most journalists say, an unemployment rate is not the percentage of youth NOT having a job, it is the percentage of youth IN THE ACTIVE POPULATION, not having a job. If almost no youth is in the active population, a high unemployment in that category is not a problem.\n\nCountries have VASTLY different active population, especially for the youth. \n\nIf in country A 80% of the youth are full time students not looking for work, and 10% are having a full time job, and 10% are looking for one, you'll have youth unemployment rate of 50% (only 20% are in the labour force, 80% are not so those are not counted to calculate the unemployment).\nIf in country B you have 50% of the youth as full time students, 40% having a job, and 10% looking for one (ie same overall figure as country A), you'll have a youth unemployment rate of 20%. \n\nBut is the country B in a better situation? Are the youth of country B working because they can't afford to study (because studies are too expensive) or because they finished them early (less education than country A) or because they have a better job market?\n\nOne needs to ALSO look at the employement/total population ratio. In some countries, it is very high (ie every one works, regardless of age and sex). In others it is very low (only few categories work).\n\n\nIf you look at this data:\n_URL_0_\n\nYou'll see for the 15-19 age bracket both sexes, VERY different Labour participation rates (ie the number of people actually in the labour force, having or looking for a job):\nGermany 28.5% and Greece 8% 2012. So youth unemployement rate of let's say 10% in Germany means 2.85% of total youth are looking for a job. The same 2.85% would mean 35% unemployement in Greece because of its much lower active population.\n\nIf you look at the real figures you have for 2012 in \n\nA. Employment/total population:\nFrance (9.7%) Germany (25.8%) Greece (2.8%) USA (26.1%)\n\nB. Labour force/population\nFrance (14.4%) Germany (28.5%) Greece (8%) USA (34.4%)\n\nC. Unemployment rate (A/B)\nFrance (32.7%) Germany (9.2%) Greece (65.7%) USA (24%)\n\nBut what does C represents in matter of total population? This is what is important to really gauge the scale of the problem. The number of youth looking for a job/total youth population, ie the UNEMPLOYEMENT/POPULATION. For Greece, this means 65.7% (very high scary figure) but of ONLY 8% of the youth (super low)\n\nHere is the result, ie the percentage of youth unemployed (ie looking for a job) of the total population of youth (and not only those in the active population).\n\nFrance (4.7%) Germany (2.7%) Greece (5.2%) USA (8.3%)\n\nSo the unemployment of youth concerns a much bigger part of the youth population in the US than in Greece... even though its unemployment rate is many times smaller (24% vs 65.7%)...\n",
"The Netherlands might be a bad example as all policies are aiming to keep this figure as low as possible.\n\nSome background information: Real estate values dropped a lot over the past couple of years and as a result in many households the mortgage is higher than the amount of money their house is worth. This difference easily hits tens of thousands of euros. These people can not move because even selling their house will result in a net loss. Plenty of people are currently losing their jobs. Since they can not go anywhere these people, with multiple years of experience, will gladly accept entry level jobs.\n\nEmployers prefer to hire these people because they get experienced people at entry level salaries. It is not uncommon to see entry level job ads requiring multiple years of experience. If you are currently starting on the job market, you're shit out of luck.\n\nNow here is the beauty of the system. In order to be counted as unemployed, you need to register with the government. This is the only way to get 'free' money. In order to be eligable you will have to follow training programs if requested and you'll have to apply for x jobs per week/month. You are required to take on any job that is actually offered. The problem with this is that applying for a job in your own field is hard if you are working in a factory 40 hours a week. Besides that, paying off your student debt with a minimum income is not going to give you a financially stable life.\n\nAs a result a lot of young people decide to stay in the educational system. They have already been studying for at least 4 years, and racked up some debt to persue a career. Most people are not going to give up on that, and will go and try to get a higher degree. Hoping that by the time they finish they can actually get a job they like.\n\nThis will become a problem as soon as the economy improves. All of those people who decided to stay in the educational system will come out at once. They will all be overqualified, and they all need a decent income to pay of their debts.\n\nSo it is not that the Netherlands actually has enough jobs for young people, the government is just really good at hiding this and postponing the problems.\n\ntl;dr There are no jobs, so young people stay in the educational system to study for jobs which might be available in the future. Students are not registered as unemployed therefore the unemployment problem is \"solved\"."
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fgy10d | why is it harder to find veins for injection on someone who's feeling nervous about it ? | I was given an injection with a baby needle on my elbow pit. The nurse had to switch veins 4 times (twice in left arm, twice in right arm) and still didn't manage to give me the injection. I was told it was because I felt nervous so it made my veins "disappeared". How is that possible ? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fgy10d/eli5_why_is_it_harder_to_find_veins_for_injection/ | {
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"Nervousness causes high blood pressure. One of the causes of high blood pressure is constriction of the blood vessels thus making them smaller and hard to find. Add in the fact that not everyone has the same body make-up, I.e. some people may just have naturally smaller/less flexible veins or their veins don’t run in exactly the same way, can also contribute.",
"Likely to do with vasoconstriction, which is the narrowing of blood vessels. When you get nervous, your body releases adrenaline into the bloodstream. This serves several purposes but one of the effects of adrenaline is vasoconstriction. This could lead to a smaller target for the nurse to hit with a needle. Also, adrenaline can cause increased body movement which can make it more difficult to be accurate with the needle.",
"So, from a theoretical perspective:\n\nYour body goes through something called sympathetic stimulus during stressful situations - it is colloquially called a \"fight or flight\" reaction. The body does several things with this, it reduces blood flow to your gut (don't need to be digesting things when running from a tiger), activates insulin (to get glucose into your muscles, where you are gonna need it to run from a tiger), dilated the pupils (so you can see the tiger better), increases blood flow to your heart, and increases heart rate (definitely need that with tigers around), and *decreases* peripheral blood flow (to prioritise the central organs, like your heart and lungs) by constricting your veins. Smaller tubes, less blood in them, more blood for your heart. This increases your blood pressure too.\n\nFrom a practical perspective, the venous constriction is actually relatively small, certainly compared to other factors affecting how easy it is to get a needle in, like hydration.\n\nYour nervous disposition also has an effect on the person putting the needle in. I am massively needle-phobic, and I really hate cannulating other needle-phobes, cos I know what they are going through, and it makes me feel under massive pressure to get the vein first time, which inevitably makes me miss."
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2t5gal | how come when i dream something relevant happens in real world? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2t5gal/eli5how_come_when_i_dream_something_relevant/ | {
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"You dream many things per night and some of them are relevant. Or maybe they are not all that relevant, but can be interpreted in a strange way to make sense to you. Like in your example, it could have been your brother, your father, anyone calling, anyone on the TV etc. you just want it to fit, so it does. \nThis will be paired with the confirmation bias. You dream 99 nights without it fitting, after that, 1 dream seems to fit \"perfectly\" like your example and you remember this one but disregard the rest."
]
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||
j2pol | explain me stocks (what i should look for, what types are there). | More specifically: I am spending a bunch of money in random stocks, but don't know what things I should be looking at. They are things like dividends and other technical terms. Also, there are many other types of stocks like mutual funds. Share your knowledge. (Also, I wasn't sure if this topic would be more towards Askreddit or this thread, but I will start here) | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/j2pol/explain_me_stocks_what_i_should_look_for_what/ | {
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"Honestly, this is your best shot at learning about [stocks](_URL_2_)\n\n\nThere is no easy answer to any of the things you asked.\n\nStop spending money as if it grows on trees. \n\nalso here are some important links that you might want to take a look at\n\n_URL_0_\n\n_URL_3_\n\n_URL_1_\n",
"You aren't smart enough to pick winners. Almost nobody is. You are best off buying an index fund like SPY or QQQQ, which contains hundreds of stocks so your risk is spread out and one company's trouble won't take down your retirement. As you get older you should have an increasing amount of your money in bonds rather than stocks. "
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"http://www.djindexes.com/",
"http://www.standardandpoors.com/home/en/us",
"http://www.investopedia.com/university/",
"http://www.nasdaq.com/"
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3k8zxw | how did people used to find their penpal, back in the day? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3k8zxw/eli5how_did_people_used_to_find_their_penpal_back/ | {
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"I found some in the back of a magazine called Stickers, for sticker collectors, back in the 80's. It was in the classified section where people could advertise that they wanted pen pals to write to them about the hobby.",
"There were penpal sections in newspapers, magazines and such. For example gaming magazines.",
"The United States Postal Service had a penpal program. Also highschool language classes used a service to pair up penpals from other regions of the world. ",
"We did them as a class project, so the teacher gave us the names and locations, it was somewhere in Guatemala as I recall."
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2pj3xi | why do police always show up to places with their sirens on? | Wouldn't it be beneficial to keep the element of surprise on your side without announcing your presence with loud noises and flashy lights? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2pj3xi/eli5_why_do_police_always_show_up_to_places_with/ | {
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"If police are doing something sneaky, like a sting, then they won't use a siren.\n\nBut the siren gets them through traffic, instructs the public to clear away, and can intimidate criminals (or potential criminals) to dissuade any further crimes. You might think twice about shooting a hostage if you know there are guys outside with guns drawn."
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4332ig | why does "populism" have a negative connotation within democratic societies? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4332ig/eli5_why_does_populism_have_a_negative/ | {
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"Wiki has this definition:\n\n > Populism is a doctrine that appeals to the interests and conceptions (such as hopes and fears) of the general population, especially when contrasting any new collective consciousness push against the prevailing status quo interests of any predominant political sector.\n\nBasically it's demagogy. Pandering and appealing to emotional knee-jerk parts of people, and tending towards short-term satisfaction, as opposed to logical, rational, long-term and sustainable planning. \n\n",
"This is fairly well explained by the tragedy of the commons, see William Forster Lloyd. Basically an individual person is likely to look out for themselves, with rational interest in short term success /safety. Their interest will not take into account what is good for the majority however. This is one of the arguments made against communism, for example. An Ayn Rand supporter would say that capitalism works because working towards your rational self interest is economically supported, jobs and taxes are levied as a byproduct of 'selfishness'. ",
"Populism is a political philosophy that is not truly represented by any of the candidates for President, and not accurately described by the posts so far. People seem to be defining populism based upon how they think it fits into their view of hour our government should or does work, while populism has been around for much longer than we have.\n\nIn its purest form, populism is a belief in the rights and power of the people against the privileged class who exploit them, especially through economic means. These \"elites\" typically are hold power in the government and work hard to maintain the status quo. One of their most successful tactics is to drive a wedge between the underclasses by convincing the middle class that the welfare class is their greatest enemy.\n\nFDR may have been the last, closest thing we have had to a real populist, not very popular with the upper classes. Nowadays, populism is used pretty much as a derogatory term, although people generally go further over the top. I heard someone the other day call Mr. Trump a populist, which left me shaking my head. Speaking to issues of concern to many of the middle and lower classes does not make one a populist, at least in the historical and philosophical sense.",
"It's generally associated with unconsidered, \"passionate\" mob rule as opposed to the carefully considered, respectfully debated consensus upon which democratic rule relies. It's generally thought of as the sort of dark side of democracy where people are led down a policy path based on their anger and frustration instead of peacefully reaching a consensus on an issue. "
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74z0xe | why do wifi routers need to be power cycled periodically? are there any that don't? | It seems like the older they get, the more often the procedure is necessary. I need to reset mine once a day or every other day. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/74z0xe/eli5_why_do_wifi_routers_need_to_be_power_cycled/ | {
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"Routers do NOT need to be reset periodically. If you set it up correctly and installed its firmware then you shouldn’t even be touching it for months or years. If you have an older modem then it could possibly be set on DoD and you’ll need to figure out how to make it a permanent connection. "
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3eofx6 | why do towels have a band without fuzz on each end? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3eofx6/eli5_why_do_towels_have_a_band_without_fuzz_on/ | {
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"It is there so the towel does not fall apart over time. There are two reasons for using this stitch over the regular \"fold-and-stitch\" version:\n\n* the fabric is very thick so it would give a very fat fold at the end which does not look appealing\n* the frothing does not make it very easy to handle\n* as there is no front and back, there is also no side that you could hide this ugly part, eg. in contrast to clothes where usually the seams are on the inside"
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5fiqj4 | what are pilots checking during pre/post flight? | What is the checklist to make sure a plane is good to go and what could prevent that plane from taking off again? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5fiqj4/eli5_what_are_pilots_checking_during_prepost/ | {
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"Im not a pilot, but as a truck driver i would assume you would check a lot of the same things as i do on my rig. Check your fluid levels, belts, guages, lights, and for leaks. I bet they check their wings and tail like i check my tires and steering. ",
"Not everything on the checklist will ground the plane, but some things can. For example, during flight a bird might have damaged a [pitot tube](_URL_0_). That wouldn't ground a plane by itself (unless *all* of them were damaged by a flock of birds), but you'd need to clean them out at the very least, and certify they were working properly before you could fly.\n\nOther items on the checklist make sure that the plane is ready for flight. Is it snowing/cold outside? Turn on engine anti-ice. Are your outboard lights on (so other planes can see you)? Are your radios setup on the correct frequencies? Did you program the flight computer? etc.\n\nAs for post flight, that's mostly to do with shutting down the electrical systems and engines in a safe manner. When you're on the ground, you're generally connected to ground-based power. You still need to switch the plane over to actually use this power, and ensure that things like the APU are not generating power. You also don't want to drain your batteries. Also, no sense in trying to pressurize the cabin when the door is open. The checklists exist to make sure you turn all the knobs and dials you're supposed to turn because despite the automation, there is still a LOT of settings that can/should be tweaked on a plane."
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fw2yke | why does yawning temporarily make a headache go away? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fw2yke/eli5_why_does_yawning_temporarily_make_a_headache/ | {
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"Headaches are mostly caused by misfiring nerves in your brain (migraines) or \"heartbeat\"/pressure headaches in the nerves/vessels/muscle that surround your brain.\n\nYawning causes a few things to happen in your body: it increases oxygen in your blood stream, increases blood flow around your jaw as you use the muscles (which is why you sometimes hear a \"whooshing\" as you stretch/yawn) and relieves pressure imbalances in your sinuses (when your ears pop). All three of these effects can impact headache pain.\n\nThe most significant \"immediate\" effects on your headache are pressure balancing and muscle stretching - especially for non-migraine headaches. Pressure in your sinuses can cause the sinus walls to trigger nearby nerves, making them to react in a throbbing pain that is relieved by a temporary release of pressure while yawning. The pain will, of course, come back when the pressure is unbalanced again\n\nIf your headache is caused by dehydration or a hangover, your brain has slightly shrunk and pulled away from your skull, alerting the nerves in a painful way (esp at your temples). By yawning, you are stretching the muscles in your jaw and temples, making nearby nerves fire a sense of \"pleasure\" that overrides the \"pain\" from dehydration - it's a very similar principal to rubbing an area near an injury to reduce the feeling of pain. Once you are no longer doing that, the pain returns. Yawning also stretches muscles that can be tight with painful tension (due to stress or exhaustion), and the temporary relax + stretch makes nerve firings associated with constricting your muscles go away.\n\nYawning during migraines is a little different because migraines are (to our current understanding) misfires of nerves within the brain itself. Yawing is usually a sign that a migraine is coming on, likely because the brain is reacting to random nerve firings the same way it reacts to exhaustion - by trying to get more oxygen. There is no real evidence that yawning lessens migraine pain in a physical way caused by an increase in oxygen, but the action may temporarily district you from your headache."
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ryol9 | hasidic judaism (or jewish mysticism) | What's the core of their belief and how are they different from other branches of Judaism? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ryol9/eli5_hasidic_judaism_or_jewish_mysticism/ | {
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"Alright, first of all, not all Chasidim (-im generally means plural people in Hebrew) are mystics, nor are all mystics Chasidim. But you will usually find more Chasidic Kabbalah scholars than you will Reform. (Anecdotal evidence: I knew a Chabadnik who started Reform and eventually became Chabad.)\n\nChasidim (and especially the Chabadim, one of the most popular form of Chasidic Judaism in the US) feel that besides devotion to G-D, one must study G-D's ways as well. The Chabad movement took it further and said that it wasn't enough to just give G-D and Judaism your heart; you had to give your mind and your wisdom as well. No mindless devotion to the Law for them! They believe in studying always the Talmud (thousands of years of commentary on the Torah, the first five books of the Bible) and don't think that just saying the prayers and keeping the commandments are good enough. One has to always be learning.\n\nRabbis in the Chabad (and also most Chasidic movements) are not priests or superiors, so much as they are a supervisor of sorts. (One thing that drew me back to my family's Judaism was the idea that one is expected to argue with the rabbi, as that is one of the best ways to learn. True, he'll usually win, but that's not the point.)\n\nSo -- Chasidic Jews are Orthodox Jews who devote themselves to a strict interpretation of the Law. Chabad also devote themselves to learning, to spreading wisdom, and to a general appreciation of life. If you're ever at a Jewish meal, and there's one guy with long hair, a long beard, and a glass of vodka in his hand, telling you that G-D commands all to make three *l'chayim* (toasts) in his honor, that's the Chabadnik. \n\n(By the way, the 'ch' can be spelled or pronounced as 'H' and you won't be too wrong. But properly... pretend you have a hair in the back of your throat, and you're at dinner with your girlfriend's family, so you don't want to just cough it out in front of them. That gentle throat-clearing... THAT'S the Hebrew 'ch.')\n\nEDIT to finish your question: A general view of the other branches of Judaism:\n\nOrthodox: for all practical purposes, follows all the *mitzvot* or commandments. They keep all the dietary laws, they pray in separate rooms in the Synagogue (Men in one, Women in the other... it's supposed to keep your mind off the other sex), and do their best to live the way the Torah and the Talmud say Jews should live. Chasidic Jews are almost always Orthodox. The way they live and worship is generally the same since the Second Temple was destroyed in AD 70. (Of course, they use technology... except on the Sabbath. From sundown Friday to sundown Saturday, they will not drive, turn on (or off) any appliance, and do no work whatsoever. Most congregations have a \"Shabbos Goy,\" a non-Jew who will turn things off, lock up the Synagogue, and other little tasks that have to be done.)\n\nReform: this movement does their best to blend in with the surrounding population. They may or may not keep all the dietary or cultural laws, but they still say the prayers and practice Judaism. For a long time, they were the only ones who had female rabbis, but this is slowly starting to change.\n\nConservative: this movement sprang up as an answer to Reform Judaism, and is roughly a happy medium between the two. Many conservative will make small changes to the cultural laws in order to better live in society. There are Conservative female rabbis, now, and women in the congregation are more engaged. You won't see one firing up the barbecue to cook up some pork ribs on Saturday morning, but they may be a little more lax on the laws (on a personal basis) than Orthodox.\n\nEDIT #2: Meant to say that Chabad is *one of the* most popular forms of Chasidism in the US. "
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4dauhr | why is the ph of water important for plants but not animals? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4dauhr/eli5_why_is_the_ph_of_water_important_for_plants/ | {
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"My tomato plants that I'm growing hydroponically (i.e. in water) grow within a pH range of about 5.5-7.0\n\nMy fish grow in a range of about 6.5 - 7.0.\n\nSo I think pH of water is important for both plants and animals, and probably even more important for animals? But it probably depends a lot on which plants and which animals, are they're all likely to have different abilities to cope with different pH levels.\n\nWhich animals and plants were you talking about in your question?"
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3r7grd | why do tomato based foods stain tupperware? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3r7grd/eli5why_do_tomato_based_foods_stain_tupperware/ | {
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"Tomatoes contain a compound called lycopene that reflects light strongly in the red portion of the visible spectrum. The lycopene binds to the plastic in the container causing it to take on a reddish tint. ",
"You can prevent a great deal of the staining beforehand by using cooking spray to coat the plastic ware before storing the tomato based foods. You can remove some of the stains w/o ruining the containers by using a bleach soak - or a phosphate containing (commercial type) dishwasher detergent.\n\nTL:DR use a glass bowl to store your marinara sauce.",
"But the real question is do Italian families just have a shit ton of stained tupperware? Completely serious here."
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10h7zb | dust | what is it made of? how does it get to all those weird spots? how does it get into virtually untouched spots it seems. What is dust
| explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/10h7zb/eli5_dust/ | {
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"Dust is made of a collection of things: dead skin, dust mites, dust mite feces, pollen, smoke, soil, hair, and other materials. Dust particles are very small and light so they get blown around easily in the air. They spread out to fill a room top-to-bottom like a [cloud in a bottle](_URL_0_) but for your whole house.\n\nSome of the dust settles onto surfaces. Some surfaces, like doorknobs, you constantly touch which wipes the dust off the surface, before it builds up to a point where you can see it. If it's a surface that rarely gets disturbed, like the top of your television, it keeps building up until you grab a washcloth and wipe it down. ",
"How does so much of it wind up on top of and on the sides of my ceiling fan when it's been *on* for the past month?"
]
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2r8mu5 | why is murder always the most severely punishable crime? | Why is it that no matter how much pain and suffering you inflict to a living person you will always get a lighter sentence than if you killed someone quickly with a relatively short amount of suffering? Even if you torture someone and ruin their lives and they end up killing themselves later. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2r8mu5/eli5_why_is_murder_always_the_most_severely/ | {
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"It's simply the most permanent way to harm someone. I do agree that there are other ways to harm people that should result in harsher sentences. ",
"Because once your dead, that's the end of the road. To be taken from a life, no matter how miserable it may seem, or even be, is worse than a life sentence. Even a useless scum bag murderer gets to live, inside of a cage. ",
"In some cases Treason may be more serious than murder. ",
"Because in a human society, the human life is the most valuable. ",
"if reincarnation was proven true would murder still be as severe?",
"Imagine a society where there are only two capital crimes: murder and robbery. For the sake of argument let us say any crime with a surviving victim has a 75% chance of being \"solved\" and any crime with a dead victim has a 45% chance of being \"solved.\"\n\nIf you murder someone, there is a 45% chance you will be caught, tried, and then executed.\n\nIf you rob someone and then leave them alive, there is a 75% chance you will be caught, tried, and then executed.\n\nIf you rob someone and then murder them, there is a 45% chance you will be caught, tried and then executed. \n\nSee how murder just changed you chances of execution from 75% to 45%? That is exactly what a lawful society should avoid. You never want to make murder attractive for a criminal. You want, if possible, to maximize the chance the victim lives and the criminal is brought to justice. \n\nYour punishments should be tiered to reflect this. You want the criminal to think \"Killing this person isn't worth the smaller risk of much greater punishment.\" ",
"Your premise is flawed, I've seen plenty of people get convicted of second or 3rd degree murder and serve less time than people that were convicted of treason, kidnapping, arson or rape. You can get very long sentences or even life for those charges, second or 3rd° murder doesn't often mean a life sentence. "
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4ub0s3 | airplane formations | Other than the Geese/Mighty Duck flying V, why? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4ub0s3/eli5_airplane_formations/ | {
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"Different formations serve different purposes. Some just look good for display, and some are designed to maximize the aircraft's effectiveness in combat. \n\nEspecially in the pre-missile-and-radar days it was important for combat aircraft to fly in mutually supporting formations. Bombers flew in tight box formations to maximize the effect of their defensive guns. Fighters generally flew in 2-ship elements. You attack, your wingman watches your back. Other elements of the formation would stay high, to watch for enemy fighters, etc."
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8m527b | why does light only penetrate 1000 meters of the ocean and not the entire ocean? | I read that light is detectable at a depth of 1000 meters, but photosynthesis is only possible at 200 meters. The verbiage used by the article I read was "significant light is only present at above 200 meters," but does "significant" mean the energy of the photons at that depth is diminished or simply that the frequency of photons hitting the sensors is decreased?
Is photonic energy simply absorbed by the ocean to the point where photons can no longer exist? Or does the "wave" of light energy dissipate into the ocean like a sound or shockwave would?
Moreover, are there other methods of gathering information through the medium of water that are more effective than light? For example, is the effective range of SONAR greater than that of, say, a light source? What about low wavelength vs high wavelength light?
Sorry if it seems like I'm asking for a 101 in photons and electromagnetic energy, never learned this stuff in physics.
Thanks in advance. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8m527b/eli5_why_does_light_only_penetrate_1000_meters_of/ | {
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"Roughly speaking, every metre of water will reduce the light by a fraction. Let's say that after 10m half the light is gone. After 20m, only a quarter would be left. After 100m, only a thousandth of the light would be getting through. (Number pulled out of my thin air.) In practice, presence of creatures/debris/different pressures/etc will affect it, but broadly speaking it will decrease exponentially with depth.\n\nSonar is a wave in the water itself. As it propagates differently, it does not decay exponentially in the same way, allowing it to potentially propagate far longer distances. How it does propagate is rather complicated, and dependant upon a lot of variables, especially the frequency. Most frequencies would not work, sonar uses frequencies specially chosen for how well they function at the task.",
"Light runs into stuff and bounces off stuff. At some point there's no more light to continue.\n\nSame thing happens in space too. Space isn't completely empty, and over a large enough distance, the light can be obscured.",
"because water isn't 100% clear. it's pretty straightforward. just like paper isn't 100% transparent, or your hands aren't 100% transparent.\n",
"No one seems to be answering your question with photons:\n\nThink about light from the sun as a hail of lots of photons.\n\nEach photon travels until it hits something. Some things can “bounce” photons off them, some things just suck in the photon.\n\nLots of photons from the sun make it through the air and start travelling into the water. But seawater has stuff floating in it that absorbs photons. For each metre of water, some photons will hit something, and some will make it through without hitting anything.\n\nIf you look for photons 300 metres deep in the sea, you will only find the very lucky photons who made it through 300 metres of water without hitting anything, and hardly any photons are that lucky.\n\nEdit: I just thought of a good analogy – it’s like a crazy guy spraying a machine gun around in a forest. Bullets stop when they hit a tree, but some bullets can go quite far before they hit a tree. If you can get a mile away from the crazy machine gun guy, your chances of getting hit go down to practically zero.\n\nEdit 2: please stop accusing me of being an American.",
"The spectrum also dissapears in order from lowest to highest frequency. one color every 10 meters or so. \n\nROYGBIV\n\nSO at 50 meters its kind of blue green. ",
"Light or visible light is a spectrum, we will call it X.\n\nThe photosynthetic spectrum is a subset, we will call it Y.\n\nIt is possible for X to penetrate far deeper than Y. And for Y to require more energy to occur whereas simply detecting X requires far less energy.\n\n_URL_0_\n\n\n\n_URL_1_",
"Simply speaking there's only so many photons per square unit of measure. \n\nAs we travel deeper in the ocean, we pass more things. \n\nEach of those are dodged by photons until they are not.\n\nYou run out of photons eventually.",
"Here's something that nobody seems to answer: water isn't completely transparent, it's just very, very translucent. Even if the water was completely free of particles, after about 200-300m you wouldn't be able to see any light. Only a true vacuum can transmit 100% of the light that passes through it. And a true vacuum doesnt actually exist anywhere in nature that we know of. We can get close in a laboratory, but that's it. Even deep space sucks up light, because all of it has a tiny tiny bit of matter floating around in it, like a couple atoms per square foot or something. But that's enough to reduce light, if you look at it with enough space between it and you. That's one reason why, incidentally, that some stars appear brighter than others. If outer space didnt diminish light whatsoever, the entire sky on average would be aapproximately as bright as the sun. Any physical matter sucks up photons, given enough of it. It just takes about 300m of water to see that it's not actually transparent.\n\nAs for photosynthesis, it's a process that requires a minimum threshold of light to make it happen. Without that minimum amount of light, there isn't enough energy to break/create the chemical bonds that are required for that process.",
"Photon energy is determined by the frequency (color). When light get weeker in the ocean, it's the number of photons getting smaller.\n\nThe reduce of photon numbers in water could be scattering (thinking of photons bounced away by particles in water) and absorbtion by either water or other stuff in the water. Scattering and absorbtion are both frequency dependent.\n\n\"significant light is only present at above 200 meters,\" means for most frequencies, the photon numbers are much smaller after 200m.\n",
"I felt everyone else is explaining it complicatedly. The sea has lots of particles floating around and they take in some of the light. Now imagine a really fine siv. You can see through it but if you take 3 or 4 of them it makes it really hard to see all the way through. The particles are small but over so many metres of them they add up and crisscross each other that the light can't get through.",
"Easiest way to think about it. Let's say you are walking forward, through a forest and cannot turn left or right. But not just you, you and a million people.\n\nIf the forest is only a few trees thick, then there's a high chance you can make it without hitting a tree. So a few trees thick forest maybe 800k would make it without hitting a tree.\n\nBut add another row of trees. And another. And so on. Eventually the chances that even a single person could walk through the forest becomes 0 because there's too many trees in the way.\n\nSame goes for atoms and light. The light flies through and the atoms of water because there's mostly empty space. But once it goes through enough water the chances of light not hitting an atom becomes 0.",
"The deeper you go, the more dense the water becomes, making it harder for individual photons to travel a clear line to the bottom. Eventually the photons collide, or bounce and reflect and that is where the absence, or lessening of light occurs. Think of it (when there is no light) as throwing pebbles at a fine mesh, the holes are too small and it is to dense (in thsi case, compact) for the larger particles (represented from the pebbles) to penetrate this mesh. This is why clean shallow water is crystal clear and light as opposed to its darker forms in deeper spots. Sorry for bad English.",
"How does light make the ~93 million mile journey through space without the same thing happening? (There's lots of space dust/debris)",
"In space it is a tight ray. *makes tube with hands*\n\n\n\nWhen it hits the air, it has to wiggle through it. *Wiggles fingers like rain* That's called 'Diffusion'.\n\n\n\nWater is like 100 times thicker than air, so it diffuses faster. *spirit fingers*\n\n\n\nSONAR is an effective but messy way to detect things underwater. The S in SONAR stands for 'sound'. Light is made of photons. Water is made of Atoms. Photons have to go into an Atom and then warm it up enough to drive another Photon out, if it doesn't then it becomes heat. \n\n\n\n\nSound is a wave of energy that moves many Atoms. It's like with a train, when you push on the rear car it pushes all the ones in front of it. That force works on water Atoms too. If there is enough force it will bounce off solid objects and you can use the speed of sound underwater and the time it took for your sound to get there and back. SONAR can harm living things. There are different types of SONAR to try and make them safer to use. \n\n\n\nLIDAR is a fusion of the two. It uses a high intensity beam that bounces off objects to a receiver. It uses math and triangles to calculate distance. This technology is still young though.\n\n"
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2arj2i | doing x in your life decreases/increases your risk of getting y cancer by z%. how do they determine the percent risk? | For example, I'm personally reading an article that says "Men who drank 2 to 3 cups a day had a 10 percent lower risk of mortality, and those who drank 4 to 5 cups per day had a 12 percent lower risk." We also see things like "Smoking increases your risk of lung cancer by whatever% over that of nonsmokers!" How do they go about determining these values? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2arj2i/eli5_doing_x_in_your_life_decreasesincreases_your/ | {
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"They look at a sample of the population, made up of varying groups within that sample, and they look at their habits and the outcomes.\n\nIf they notice that some men are not getting cancer while others are, or some men are being hospitalized for similar reasons while others aren't, they then look at the similarities between the men are try to find a cause.\n\nOnce they have that cause, they try and look at why it might be the case.\n\nFor cigarettes they know that people who smoke and inhaling cancerous chemicals, and that's why their risk of cancer is increased.\n\nFor (I'm assuming coffee) drinkers, it might be because the caffeine is A) giving their heart a boost and a little work out by beating faster and therefore minorly improving cardio B) caffeine is a diuretic and therefore may flush stuff out of the body\n\nThey then run more tests to conclusively prove these theories and then release the information."
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151lkv | baby boomers and the animosity towards them | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/151lkv/eli5_baby_boomers_and_the_animosity_towards_them/ | {
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"Copy-Pasta of my comment from [this thread](_URL_0_).\n\n > When the US had crushing debt after WWII, the top marginal tax rate was raised to over 90%(!!!). Our debt was far worse than today and the WWII generation was not willing to pass that debt on to their children. This WWII debt was paid off relatively quickly and responsibly.\n > \n > The boomer generation is very often criticized because they have been hesitant to take similar action in the public sphere. The Cold War again caused national debt to skyrocket, but instead of raising taxes, they lowered them and let the debt balloon. Instead of reforming programs that are on shaky ground, they insist the government not touch them.\n > \n > To many, they just seem awfully close to violating the Boy Scout Rule, not leaving the country better than they found it. The 60s-70s were no utopia, don't get me wrong, but people see problems they definitely could have solved or at least contained which they did not.\n\nTheir stewardship of the country has left a lot to be desired in many peoples' eyes.",
"The United States of America always had a tradition of sacrificing to make sure the world was better for their children. In World War II, for instance, people turned in bits of scrap metal and even tin foil to help the war effort, and dealt with rationing, etc. Example:\n\n_URL_3_\n_URL_2_\n\nThe same sacrifice was true with raising taxes to pay for debts, and so on.\n\nThen came the 1970s and the very bad problem the USA had to deal with was an oil problem. A man named Jimmy Carter was president and saw that we had another huge problem we needed to sacrifice for. He suggested Americans put on a sweater and turn down the thermostat so we could beat our dependence on foreign oil, and gave speeches like this:\n\n_URL_1_\n\nThe Boomers tossed him out of office in favor of an aging actor who told them everything was all right.\n\nThe Baby Boomers betrayed that sense of national sacrifice, and so today, we still have a lot of problems with oil dependence, and debt, etc. but compounded so badly they are leaving the world a worse place for their children. Instead of being a major sacrifice, wars are now fought as though they had no effect on the general population except for yellow magnets on cars like this:\n\n_URL_0_\n\nThe unwillingness to sufficiently address major problems and the betrayal of our traditions is why people feel the Baby Boomers were a dishonorable generation."
]
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"http://www.pbs.org/wgbh/americanexperience/features/primary-resources/carter-crisis/",
"http://www.timemoneyandblood.com/images/posters/American/donate-scrap-metal.jpg",
"http://www.ohiohistorycentral.org/images/972.jpg"
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3z1kmw | what is the purpose of the black paint under the eyes? | Also if historical context could be explained that would be great too!
Edit: the black paint used in sports | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3z1kmw/eli5_what_is_the_purpose_of_the_black_paint_under/ | {
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"It reduces glare (reflection off your upper cheekbones) from the sun/lights and makes it so that you do not have to squint as much. Besides being used in many sports, it is also used by hunters and military/ warring peoples. As for historical context, it's been done for a very long time because it's copied from nature - many non-human animals like cheetahs and gazelles naturally have the useful glare-reducing darkness under their eyes. "
]
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d42crs | how are people able to salvage data that has been deleted? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d42crs/eli5_how_are_people_able_to_salvage_data_that_has/ | {
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"Data isn't actually deleted when you hit \"delete\". When you hit \"delete\", you're telling the Operating System that it is OK to overwrite the area the data is taking up. If you delete something by mistake, and you don't write anything to the disk, the data is still there, and you can recover the data.",
" Windows (and other operating systems) keep track of where files are on a hard drive through “pointers.” Each file and folder on your hard disk has a pointer that tells Windows where the file’s data begins and ends.\n\nWhen you delete a file, Windows removes the pointer and marks the sectors containing the file’s data as available. From the file system’s point of view, the file is no longer present on your hard drive and the sectors containing its data are considered free space.\n\nHowever, until Windows actually writes new data over the sectors containing the contents of the file, the file is still recoverable. A file recovery program can scan a hard drive for these deleted files and restore them. If the file has been partially overwritten, the file recovery program can only recover part of the data.",
"I'm not entirely certain of the process, but data that you delete doesn't simply \"dissappear\". It just gets marked as unused space and sits there and does nothing until it gets overwritten by something else. Data salvaging is just searching through that unused space to find the data you're looking for. I don't know exactly how they accomplish this though."
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d70rvp | why do some batteries puff up? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d70rvp/eli5why_do_some_batteries_puff_up/ | {
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"A swollen battery is the result of progressive degradation of the chemicals that generate power. The reaction that pushes electrons through the circuit can't work the way they were designed to, and part of that failure involves *outgassing,* or the creation of gases and vapors where they're not intended. This swells the battery casing, and might cause a breach and leak of the battery's contents."
]
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bibh8o | how does the 20 questions electronic game work? | It’s able to guess so many different things with the most basic question, how is it so consistent? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bibh8o/eli5_how_does_the_20_questions_electronic_game/ | {
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"It's basically a \"binary search\". Let's look at guessing a number between 1 and 100.\n\nYou pick a number in the middle (50) and *that rules out half the questions*. If the number you want is higher or lower, you repeat this (25), and again (12) and again (6) and again (3) and again (2). You can mathematically show that you can always find the number in 7 or fewer guesses by following this. In fact, the number of things you can identify by a series of *N* yes/no questions is 2^*N*.\n\nFor *N* = 20, that gives you over a million possibilities. The number is *even bigger* if the question allows for multiple answers other than just yes/no.",
"\n\nFirst, come up with a bunch of yes/no questions that would be good for a 20 questions game.\n\nSecond, collect a bunch of objects, and answer some or most of these questions for each object.\n\nNow, you have a good database of objects and an associated list of the yes/no answers for each object. \n\nWhen it comes time to ask a question, have the computer look through the list and find a question that has roughly half of the objects with a yes and half with a no. When the player answers, your list of objects is now half as small. If some of your objects didn't have an answer for that question, keep those too. Now, look at your remaining objects, and repeat the process, always picking a question that splits the objects into about half yes and half no. After 20 questions, halving each time, you will have sorted through about 1,000,000 possible answers. The questions might not always seem to make sense, but to the computer, this is the most efficient way to find your item.\n\nAt this point you have a working system, but it takes a long time to get this data. If you are smart, you can make your game even better the longer it gets played \n\nNow, have a bunch of people play the game. LOTS of people. Keep track of their answers as you go. Put it on [A WEBSITE](_URL_0_) so you can get answers from thousands of people. If they have an object you couldn't guess, add it to the list, and save the answers you got, or update the answers you already have. If you get lucky and narrow the answer down before all 20 questions are used up, look at some of the other questions for that object you don't have answers for and ask those so you always get more data. This is why if you play the online version it might seem like it's on the right track and suddenly ask if your potato \"wears a cape\". It already knows the answer is \"potato\" ; it's just collecting more info about potatoes to make it even smarter. You could even ask the player if there is a particular question they should have asked and if so add that to the list of possible questions for next time. If people sometimes answer differently for the same question, keep track of the percent yes vs no and take that into account when asking your questions (i.e. If \"are potatoes healthy\" gets 50/50 yes or no, don't eliminate that answer right away if you ask that question. \n\nLast, grab your latest version of the database, put it in the toy, and done."
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24og33 | how is chewing bones good for dogs teeth, and can it benefit humans? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/24og33/eli5_how_is_chewing_bones_good_for_dogs_teeth_and/ | {
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"Their teeth are specifically designed to crush softer bones like ribs and vertebrae unlike our teeth. When dogs eat lots of softer foods like commercial dog food their teeth can't get tartar build up on it just like our teeth; gnawing on bones will help scrape the build up off."
]
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||
avisrz | how do audio recordings that are stored in binary code on devices get re-converted to the sound that comes out of my phone’s speakers? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/avisrz/eli5_how_do_audio_recordings_that_are_stored_in/ | {
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"It is covered thanks to a device called a DAC (digital to analogue converter).\n\nWhen audio is traveling in a speaker wire, it is just an electrical impulse - it has a voltage and a frequency based on what the sound is. That voltage and frequency is then amplified (by an amplifier) and pushed to a speaker cone, which vibrates at that specific amplitude and frequency to make sound waves in the air.\n\nA DAC is able to take the bianary data and create impulses in the speaker wire at that specific voltage and frequency, which then travels down the wire."
]
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42tx06 | how can a 60hz monitor have a response time of 5ms when 1/60hz = 16.7 ms? | Shouldn't the "real" response time be 16.7ms, since if you give an input exactly after a frame, you will only see it 16.7ms later? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/42tx06/eli5_how_can_a_60hz_monitor_have_a_response_time/ | {
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"The response time is usually the time it takes a pixel to change from black to white, or some predetermined gray to another gray value to estimate the average real usage. This will determine the amount of time it takes the average pixel to change to the updated value after a new frame is received by the monitor; the shorter the response time, the quicker the screen updates. If the response time is as long as a frame update interval, the screen never finishes updating, and you get a blurry mess when you are watching video or playing games; the shorter response time helps eliminate this effect."
]
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4rs845 | what is the root cause of what appears to be unequal treatment of minorities by police? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4rs845/eli5_what_is_the_root_cause_of_what_appears_to_be/ | {
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"From my point of view as a late 20s black male. The root cause is cultural conditioning, and that is something that will never go away which is why I strongly believe it's a problem that will never be solved. Now if you don't know what I mean by cultural conditioning, everything from kids movies, TV shows, commercials, what you hear on the news etc has an impact on the way you think. It's so deeply engrained in our society that it's impossible to break. Caucasians automatically think, whether they are racist or not that African Americans are more violent. African Americans feel from a very young age that the world is against them, you hear it a lot in rap songs on TV shows etc, so the mind state is completely different. I was taught at a very young age that it isn't a fair playing field and it would be something that I will have to live with the rest of my life. Now luckily I am semi successful, and have a family of my own and a son, I find myself passing on those same teachings to him. Fair or unfair, it doesn't matter, some people call it white privilege and I don't necessarily see it as that. To me it's more so of a black disadvantage. ",
"Young black men are responsible for 50% of violent crimes. They tend to live in concentrated areas (Chicago, DC, ATL, Baltimore). Naturally cops are going to focus on the heavy crime areas because the people that live there need help\n\n\nThe problem is the cops focus on this area can be racist. Or it might just seem racist to the inhabitants. Say you pull over every young black male, obviously many are going to be innocent of serious crimes. But now they are harassed. And they might be breaking small crimes (weed, traffic, registration) so they are more likely to be arrested or ticketed."
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6cvu5t | do animals get sick from licking another of the same animal it's wounds/blood? | Is this possible to happen if it ever happens that is? Or do animals know this and never do it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6cvu5t/eli5_do_animals_get_sick_from_licking_another_of/ | {
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"Whenever an animal hunts other animals and eats meat, they're eating some of their blood. Their stomachs just pulverize everything. Same for if they were to lick another of the same species. Same for humans, too, pretty much. Something like a blood transfusion would probably cause problems, though, because it bypasses the stomach. And humans can get problems from having too much iron, not sure if carnivores experience anything similar."
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50t450 | why can't a human be frozen while still alive, and jumpstart and come back to life when they thaw out (like avatar)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/50t450/eli5_why_cant_a_human_be_frozen_while_still_alive/ | {
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"Someone with more knowledge can come by with more info, but the primary reason is that our cells cannot withstand the ice crystals that form when they are frozen. When our cells freeze they rupture and die. If all of our cells freeze, they all die. "
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5ng3cs | how do radio stations broadcast album art? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5ng3cs/eli5_how_do_radio_stations_broadcast_album_art/ | {
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"Radio stations have extra radio bandwidth that they don't need for the audio alone. They can use this bandwidth to send additional data to your radio such as the station name, song title, artist, or I guess the album art. It's essentially sending data over a wireless internet connection, point-to-point from the station to your radio. This is not an efficient connection though due to the distance and interference, so its uses are limited. \n \nYou usually need a radio capable of receiving this kind of data (and a station properly equipped) otherwise your radio doesn't know how to interpret this data and display it for you. It would just think it was noise and ignore that part of the signal. This system is also heavily regulated in how it can be used."
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5gush7 | the us is known as the "no vacation nation", the only developed nation without mandatory pto. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5gush7/eli5_the_us_is_known_as_the_no_vacation_nation/ | {
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"\"Because why should I pay someone not to work?\" That's what it amounts to basically, you can always find someone for the same job that will work for less pay or less benefits.",
"Because there's no political will for it. Laws have to be drafted and passed through the Congress and then get signed by the President. Americans have been electing politicians who tend to side with business owners, and they don't want mandatory PTO. ",
"The USA is among the most anti-regulation cultures among the wealthy nations. This dates back to our history as (1) the world's first large democracy and (2) the product of a revolutionary war fought for independence from an allegedly overbearing government (of England).\n\nIn addition to our dislike of regulations, we also have a culture in which people identify with rich business owners -- many average people imagine \"in the future, that could be me\". So people often support efforts to avoid regulating businesses.",
"For 40 years, the U.S. and the Soviet Union fought a cold war, as the world's two superpowers.\n\nThe Soviet Union stood for communism, and this caused the U.S. to take the polar opposite position, to stand for unbridled capitalism. The cold war is over, but the culture that came from this is still there.\n\nSo even today, the U.S. struggles with things that every other country has long since agreed upon and solved. This is why we don't have mandatory paid vacation, why we struggle to provide our people with health care, and so on.",
"Because large corporations (who are opposed to more regulation, especially regulation that requires them to pay people who aren't working) have incredibly strong lobbying power with US Legislators.",
"It's not regulated, but in my 18 year professional experience it is kind of mandatory. Management would encourage pto (I was never one that needed to be encouraged, but knew people that had to be). They'd get a little shunned if they didn't. family members in less professional roles, let's say a mill/warehouse job got x amount of weeks earned and they'd happily take. Move to the service industry, like wait staff or retail...they can literally become slaves an although they've earned pto it's frowned upon. Perhaps I'm completely off with no statistics, just my work experience for over 20 years and family/friends.\n\nUS is still far behind on work/life balance, regardless. \n\nEdit: not literally, figuratively.",
"Before the 1960s most Europeans worked more than Americans. Then tax rates started going up for Europeans and down for Americans. Because the government gets 30-50% of the value of your salary but none of the enjoyment you get from a day off, it makes sense for people who are paying more in taxes to work less. See the work of Edward Prescott for more on that.\nPeople who work less get paid less, and most Americans would rather work more and get paid more. Those who feel differently can negotiate to work less or work part time. America is a big diverse country and there is no need for a one size fits all policy.\n",
"a couple things:\n\nthe US is not one set of regulations, to a European think of the states as the individual countries in europe. \n\ni get more PTO via employment negotiation. the least amount i have ever had in my working life was 40 per year, higher than in the EU.\n\nin the US a large federal government is frowned upon. we would rather do things ourselves than have big brother coddle us. it works for europe and that is cool, but he have backbones here. ",
"It's not about what makes sense or not. It's about culture. Every person here is a decendant of an immigrant. It takes grit, determination and a strong work ethic to just up and leave everything you know and work your butt of in some new place hoping for a better life. Take the fact that we have self selected for people who generally embrace the the narrative of 'hard work above all else leads to prosperity', throw in our Puritan roots and our general distaste for the government intervening in our lives (compared to other places) which dates back to the revolution. You end up with a culture that lends itself to this policy being viewed differently here than elsewhere in the world.",
"Capitalism. Most people in the US care more about making money right now than the well being of people around them or future generations.\n\nSource: I am an American.",
"workers are an expendable commodity and are just another profit drain. workers contribute nothing to my bottom line, they only serve to worsen my bottom line. fuck workers...they don't do anything for me. \n\nfirst you give them safer working conditions where they won't get injured, then they'll want 60 work weeks.\n\nonce you give them 60 hour work weeks, they are going to want Sundays off...\n\nonce you give them Sundays they are gonna want Saturdays too.\n\nThose greedy bastards, once you give them weekends - they're going to want a 40 hour work week too. \n\nAll of those things cut into my profits. Man Fuck the Workers. Once you give them weekends they're going to want me to stop polluting the rivers and lakes they go to to recreate.\n\nDammit - now they've got weekends and less pollution, now they are going to start wanting paid vacations. Fuck the workers...those bastards should be paying me for the priviledge of making me money...\n\n\n(pretty much any conversation about workers rights in this country including but not limited to: vacation, minimum wage, executive pay, environmentalism, pollution control, child labor, gender pay gap, work place safety)",
"Whether I agree or not, the idea is essentially that deregulated market competition should balance out the need for regulation.\n\nCompany A and Company B are both trying to hire employee C; Company A and Company B are both free to structure the job/hours/dress-code/etc., as they please, and employee C is free to choose.\n\nSo you have Company A and Company B who are each attempting to hire the highest caliber of employee for their field from the same pool, and the best way to hire the best talent is through the best available employment package an employer can offer.\n\nCompany A offers 20 days of PTO, Company B offers 15. Employee C goes with Company D because they allow you to bring your dog to the office.\n\nIts the idea of competition in lieu of regulation as a stabilizer for equality.",
"And even if you get PTO good luck trying to use it and not be given a guilt trip or told you're \"Not a team player\". Get 3 weeks vacation, so far gotten to use 1.",
"People seem to be dancing around the truth of the matter. The truth is our \"democracy\" is almost 100% controlled by business, especially big business. Our laws are decided upon by businesses through lobbying, not politicians trying to better our population.",
"The \"No Vacation Nation\" wasn't actually the first title they came up with. Initially, they floated the idea of \"Vote against your own self-interest Nation\". Critics considered it too confusing. Then they tried \"The No Minimum Wage Nation\" but test audiences were skeptical that this would be too revealing. So the suits settled on \"No Vacation Nation\" as they knew they could maximize bootstraps much easier from the common worker using this terminology. ",
"Long story short: American political attitudes tend toward defining fairness as defending the interests of the powerful back to our founding. We've had a few bouts of progressivism, but they were short-lived and generated massive backlashes from the moneyed elites.\n\nHealthy happy workers are not necessary because workers are expendable in the eyes of big capital. Who cares about the long run when executives and shareholders have only temporary interests in business and superficial interests in society, with every interest in maximizing short term profit before moving on to the next venture? Those companies that do offer benefits only do so when the job market demands it. Huge numbers of Americans do not have enough demand for their work to be able to get any benefits beyond a flat hourly wage or commission.\n\nIt took a war that killed half a million to end slavery and huge chunks of the country's land were acquired by brute force against Native Americans and Mexico. People are still trying to abolish the minimum wage and any guarantee of healthcare, food or housing. People still protest the existence of food and drug purity and labeling and environmental protection.\n\nThe average American voter favors progressive policy when asked about specifics, but votes the opposite when the time comes. This is partially due to lack of information on policy and partly due to the idea that we are all kings in our own right and the state cannot tell us how to do business or handle our property.\n\nIt's the best country in the world to live in if you make an upper middle class living or better, but the majority have little more than trinkets and distractions to mark their lives as better than those of medieval serfs. And every serf dreams of being a lord. And there is some genuine philosophical agreement with libertarian principles and some genuine corruption.\n\ntldr: Protections for the little guy in the US are the exception to the rule and those that exist are under constant assault while others are trojan horses that hurt the little guy while claiming to protect him because 'Murica.",
"But who takes a job that does not have vacation time? I have never had a job unless I was the owner that did not have vacation time. There are choices to be made and by not taking jobs with no paid time off will make employers provide it. So in thinking about this there is a group who have no paid time off in my company. The thing is they work for 3 weeks and then have 3 weeks with no work essentially only working 6 months a year and they make 100k plus a year. ",
"because US business does not give a damn about the US worker\n\nUS business cares about profits. it uses those profits to buy politicians that pass regulations that will not decrease profits\n\nexecutive bonuses are threatened? layoffs.\n\nshareholder dividends are threatened? layoffs.\n\nless regulation in another country? close US production.\n\nUS employees too expensive? H1Bs and illegal aliens. \n\nyeah, you read that right. why do illegal immigrants come to the US in search of higher wages? because US businesses pay them. its a fraction of what US residents would earn but that's ok - it reduces prices for consumers and increases profits for companies.\n\nwanna solve the problem of illegal immigration? fine businesses found hiring illegal aliens out of existence. \n\ndon't get me started about healthcare - no job, no health insurance, too damn bad.\n\nso that's why US workers get little vacation time",
"Because we don't fuckin need to. Everybody with a full time job gets vacation time or their company won't have anybody filling their positions.",
"Wow, amazed at some of the crappy responses here. Lots of people saying mandatory isn't required, typically coming from people who work for companies that DO provide it, which are in general, well-paying jobs of a higher status. So, because a typical well-off American already gets PTO, they don't consider it important that workers of every level in America recieve PTO. The issue is not about PTO; it's about Americans feeling it necessary that they be better than others. So, they don't consider a fast food employee for example, as someone deserving of PTO- they are not worthy enough, they don't work hard enough, and they aren't skilled enough- only upper class or upper middle class Americans should have that privilege. It's really sort of like a caste system; the upper class constantly want to deny benefits to the lower class so they can retain their privileged status, and when any issue revolving around the matter is brought to the surface, the status quo is quick to jump on it and defend a system in which they benefit and others suffer. It's not fair, and the onyl motivation for it is that Americans like to look down on and trash those less fortunate by saying things like, \"well we don't need PTO for all employees- this job doesn't deserve it anyway,\" and \"Americans don't want the government requiring it,\" when the majority of Americans actually do support mandatory vacation time, albeit the majority of the poor and powerless, so it will never garner attention, and you can't rely on the majority and the powerful to raise the issue in the defense of the other side, because those are the same elitists who benefit from NOT having to pay people for time off, and also the same people who get off on being \"better\" than other Americans because they are fortunate enough to get PTO anyway.",
"This is the worst ELI5 of 2016. Like by far. This is not the platform to push your agenda on. Make some whiney post on /r/politics, they'll love you there /u/usscan"
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a7gt32 | when i’m driving, the wind can blow my car all over the road. when i’m parked, the wind can’t move my car one inch. why? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/a7gt32/eli5_when_im_driving_the_wind_can_blow_my_car_all/ | {
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"But it does move your car. If you're driving down the road and a gust of wind hits the side of your car it's going to push it off to the side until you correct it. That's because your car is already in motion but it's shifted slightly to the side during that motion. However while it's parked that same gust of wind will cause it to rock back and forth a bit. The only difference is that it doesn't feel as extreme because you're not in motion. "
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4dl2of | why do the us elections need donations? what for? what would happen if that was not allowed? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4dl2of/eli5_why_do_the_us_elections_need_donations_what/ | {
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"Funding for the various candidates does not come from the Government in the US save for a very small pool of funds used to get things started. So the money that the candidates use has to either come from their own personal savings, come from party coffers, or come from donations made directly to them for the campaign. \n\nThe parties also do not charge dues from their members as is common in many European countries. So all money that the parties have is from donations made to the party, or unused funds from candidates as they full out of the race. \n\nThe money that is collected is spent on the campaign. You have the costs of paying workers in every state to spread word of your campaign and your stances, paying pollsters to collect data, paying campaign managers and policy advisers, paying for ad time on TV and in other media, travel costs to go do speeches and to attend debates, renting locations for various events, etc. Money that is not spent can be used to reimburse any personal money spent, donated to charity, or sent to the party general fund. \n\nIf donations were not allowed the richest person would win elections because they would be able to buy the most ads and get their platform known to more people. "
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3lai0z | basic bonsai tree care. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3lai0z/eli5_basic_bonsai_tree_care/ | {
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"Bonsai are trees that are deliberately grown in a way to dwarf them, and are often sculpted into specific shapes. So you start with the standard \"give it the right amount of water, food, pot space and light\" that applies to almost all houseplants. \n\nBut the species, age and size of the bonsai all make a huge difference in how much of each it should be given when, and how it should be pruned. \n\nSo to avoid posting a book, it's probably best you go to bonsai care-related sites like this one: _URL_0_\nand look up the specifics. "
]
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"http://www.bonsaiempire.com/basics/bonsai-care"
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||
1us9jm | gold trading and how it's used to "back" currency and the like | The gold standard and so forth. If this has been asked before I wouldn't know because the search isn't working. That's my excuse and I'm sticking to it. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1us9jm/eli5_gold_trading_and_how_its_used_to_back/ | {
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"Gold was money, used in trade, made into coins or bullion, sometimes by governments, most often by gold specialists.\n\nCurrency is a substitute for the real money (though not only gold was used as money). Currency was usually a paper substitute for real money that were called \"Bank Notes.\" Ideally, for every one unit of currency, there should be an equal amount of actual money secured somewhere, usually a bank's vault. \n\nInstead of trading the gold itself, because it was a heavy metal and could be a target of robbery, people would leave the gold in the vault and trade the paper notes (that could be kept in pocket, even in large denominations) that represented a claim to the gold in the vault.\n\nThe USA started with BOTH a gold and silver money system. An ounce of silver was $1. An ounce of gold was $20. These were denominations set by law. About 1873 the government stopped allowing people to bring silver to the mint to make silver coins. So, essentially gold was the only public money, and all Bank Issued Currency (and all currency is bank issued, with one exception during the civil war era) was denominated by dollars, but \"backed\" by the appropriate proportion of gold money.\n\nThat means, theoretically, anyone should be able to take the piece of paper they got from trading to the bank that issued the paper, and get gold. FDR outlawed Americans from doing that in 1933 (and confiscated peoples gold money), and Nixon outlawed foreigners doing in in 1971 (which was only partly allowed after WWII though the \"Bretton Woods\" agreement.)\n\nThe reality was, of course, far more paper currency was made than ounces and tons of gold to back it up. Which is ultimately why a \"gold standard\" usually becomes a fraud."
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5xo4jx | why does the speed of a car seem slower when i'm inside it rather than outside? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5xo4jx/eli5_why_does_the_speed_of_a_car_seem_slower_when/ | {
"a_id": [
"dejnh9s"
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"Relativity!!!\nwhen you are in a car you are in car's frame (in other words you are moving with speed of car) and when you look from window all objects have a speed equals to object's speed minus car's speed (vector addition) which slows down everything which seems to you like car is moving slow"
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7ch067 | how does the body correctly sort food and fluid (especially when you eat and drink together)? | For example I have seen some eating contests where the participants eat huge quantities of food and drink water to held them “down” it quickly.
When it gets down your food pipes* how does the stomach and bladder get their individual shares of what’s been consumed??
*forgot the sciency name. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7ch067/eli5_how_does_the_body_correctly_sort_food_and/ | {
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"The bladder is not directly connected to the digestive system, so there's no \"sorting\" involved. The small intestine extracts water and nutrients from the food in to the blood, with the help of friendly bacteria, and you poop out what's not used with a lot of dead bacteria. The kidneys, on the other hand, filter impurities and waste products out of the blood, with some water, and sends them to your bladder. ",
" > When it gets down your food pipes* how does the stomach and bladder get their individual shares of what’s been consumed??\n\nThe sorting happens in the intestines. It makes intuitive sense that the solids you eat become poop and the liquids you drink become pee, but that isn't actually true! \n\nEverything you swallow goes to your stomach, where it all gets mixed and broken down into a soup-like consistency. Then it goes to the intestines. Your intestines absorb the water out of it (including water that used to be in solid food), and absorb the nutrients. What's left over at the end of all this absorbing is poop. Poop also contains a lot of old, dead cells from the intestinal walls, and bacteria. \n\nAll the water and nutrients that got absorbed will flow around in your bloodstream, going where they need to go. Once this is done, the extra water is filtered out by the kidneys, because a lot of the waste products we need to pee out (like urea) have to be dissolved in water. "
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b8i8i9 | why are germs so difficult to wash off, and yet so easy to spread? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b8i8i9/eli5_why_are_germs_so_difficult_to_wash_off_and/ | {
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"Because even a tiny bit that gets off or that remains can then apread to cover the whole surface in a relatively small timeframe, since when bacteria multiplies, its population size basically just straight up doubles."
]
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[]
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||
2c87p1 | why can some people only twist their tongues in one direction? | I thought since there is just one brain, one tongue, and one whatever else is inside people's heads that affects tongue twisting (muscles), that everything should be symmetrical. However, I, and I'm sure others, can only twist my tongue in one direction (clockwise). Why would this be if everything's supposed to be symmetrical? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2c87p1/eli5_why_can_some_people_only_twist_their_tongues/ | {
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"I can't twist my tongue at all. I just tried.",
"It is a purely genetic trait akin to having a widow's peak.",
"Whoa just realized that I can't twist my tongue two ways.\n\nWell it sort of works the other way but it's not quite the same."
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2rtjk5 | why is the "peace sign/victory sign" with two fingers used with positive connotation, if it was first used by winston churchill, a british man, and the "v-sign" is an offensive hand gesture there? | During the second world war, Sir Winston Churchill, the British Prime Minister used his index and middle fingers to form a "v-sign", which was then used as a symbol for victory and has that connotation throughout Western Culture; in England, a country fighting on the same side of the war, sees the same gesture as an obscene and offensive sign. Why did this come to be, and further from that, was the hand gesture offensive before Winston Churchill used it in this way?
tl;dr: Why is the "v-sign" offensive in England but not in Canada/the USA? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2rtjk5/eli5_why_is_the_peace_signvictory_sign_with_two/ | {
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"Sorry I only have time for a small part of an answer, but take a careful look at the position of the palms when people make these signs: v-sign with palm out means \"victory\" or \"peace\", v-sign with palm in means \"the finger\" in the UK and its relatives.",
"The offensive V sign is \"The Longbowman's Salute.\" The story goes that since Britain had the best archers/bows, whenever the French would capture one they would cut off the two fingers used to pull back the bow. As a result, archers would taunt the French by waving their fingers at them. I'm not sure how much of that actually happened, but that's the story."
]
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4a0nb7 | when hearing a very loud noise, that blowing sound/feeling in your ears | Things like cement saws and angle grinders | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4a0nb7/eli5_when_hearing_a_very_loud_noise_that_blowing/ | {
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"d0wfr2i"
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"text": [
"Sound is vibrations in the air. Loud sounds = stronger vibrations. If the sound is loud enough, you can feel the vibrations in your ear. "
]
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3dhcic | what and how are hot jupiters formed, and what does this mean about the creation of our own solar system? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3dhcic/eli5_what_and_how_are_hot_jupiters_formed_and/ | {
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"Hot Jupiters are basically gas giants that orbit very close to it's star. Usually at half earth distance or closer (less than 0.5 AU), usually towards the closer end. As a result they get very hot, to the point of glowing from the heat.\n\nThe top theory about how they form is that they form at normal gas giant distance (Jupiter range, ~5 AU or more) and make their way inwards by slurping up the rocks and gasses closer to the star, causing it to gain mass and lose kinetic energy. Another theory is that the gravity of other planets or asteroids change it's orbit over time and bring it closer to the star.\n\nFor out solar system it doesn't mean anything special, only that we don't have a hot jupiter planet."
]
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[]
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2crjck | the difference between a fee antivirus software like avg, and a paid antivirus software like norton 360? | Title | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2crjck/eli5_the_difference_between_a_fee_antivirus/ | {
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"Computer science major here so I know a bit about this stuff, I could drag this out but to try to explain simply, a number like 98% of viruses are just evolutions if precious viruses. All antivirus softwares look for these base differences. Free antivirus software finds these and eliminates. When you start getting paid software, their goal is to now try to up sell you from \"starter\" to premium. So paid programs like Nortan are notoriously hated for trying to be over protective blocking programs even trying to access the internet. Go for s free program like AVG, windows security essentials, or malware bytes I promise that if your computer ever gets Fubared to the point these can't fix it, not even Nortan can. \n\nTldr Why pay when free programs will do it without pissing you off",
"It depends from case to case the only way to give you a good answer would be checking what they offer and how often they upgrade. Which you can usually find on their product page.\n\n\n- some include firewalls, email checks, proxys, ... \n\n- some are only free for private use\n\n- some are just horrible\n\n- paid software may have the better support\n\n- free software may not include proxys, email check (which you may not even need) and are pay to upgrade\n\n\n\nbut \"good\" free antivirus software works just as good as a \"good\" paid software.\n\n\nEdit:\nThe most important thing is probably the update frequency. If your software only upgrades once a week you could already have the virus.\n\nBut everything else that got mentioned here (speed, efficiency, ...) depends on the software itself paying money for it doesn't have to make it better. But the nice thing with software is that even freeware can be awesome, because there are so many very talented programmers out there and the tools you need are mostly free.",
"I once read an article on this, and the following statement stuck with me:\n\n > One difference is that the paid AV software might protect you against a certain Virus, that the free one does not. The issue with this is that the Virus is so rare, it's like paying extra for your house insurance to protect you against a herd of Rhinos breaking down your walls. You just wouldn't.",
"I had a virus a few years ago that decided to use AVG as a vessel to reap havoc on my computer. This was not a typical virus and the person that made it was much smarter than the average bear, but it still left a bad taste in my mouth for freeware. I used the free trial of McAfee to get rid of it, but I ended up buying McAfee because it did the job credibly. I've had problems with AVG letting things slip before, and with paying a little extra, I think these companies get some extra funding to beef up their programs and increase their customer support.",
"For what its worth, from an Enterprise level, a commercial application adds administration functions. Distribution of updates can be controlled, then you have reporting alerting you to server / pc's requiring updates / not reporting, through to virus notifications. Also servers running Exchange (mail) will have different needs for AV scanning. Further to this, you also get support from the AV software vendor. Companies like McAfee also offer firewall and encryption products. "
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62sz94 | why peanuts without shells are way cheaper than peanuts with shells if it takes labor to shell them? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/62sz94/eli5_why_peanuts_without_shells_are_way_cheaper/ | {
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"Could be a matter of scale / volume. I would imagine nearly all of the peanuts consumed are shelled to be eaten or made into peanut butter. Shelled peanuts are sold in comparatively much smaller volume. When you produce something in very large quantities, you are able to take advantage of \"economies of scale\" that drive the price way down. This is in part because your fixed costs (e.g. Production equipment) are spread out over much more output. ",
"The ones you buy shelled are taken from peanuts unfit to be sold with the shell on. Think damaged, discolored or otherwise just not great looking peanut shells. Same idea with baby carrots. They're cut from larger carrots that are discolored, misshapen etc.",
"3 things come to mind: economy of scale, where it's cheaper to process the nuts than it is to quality control the shells\n\n2- as said, shells may have a use elsewhere, and could make shelling them worthwhile\n3- container sizes: 200gm of unshelled peanuts probably takes up quite a lot less space than 200g of shelled peanuts, lowering the cost of logistics and storage. ",
"Maybe the majority of the peanut usage goes to shelled peanuts and their products leaving a lesser amount to be sold unshelled, making them more expensive. Idk, just a guess.",
"However, peanuts inside the shells are pure peanuts, and have not been handled, or licked by rats.",
"My fiance worked in a peanut shelling plant for years and it basically boils down to them wanting to get equal profits from shelled vs. unshelled.\n\nOnce the peanuts are shelled, they're graded and sold for different prices. There's splits, jumbos, mediums, #1s, etc. I forget all the names, but there's a few more. Even the hulls and 1416s (aka the smallest bits that fall through the sorting screens) can be sold for things like livestock feed and some other random things.\n\nSo basically, if they break the peanuts up and grade them, they can potentially make a lot more money sending them off to different places. If they get sold whole, then they have to set a price that will somewhat match up with what they would be worth sorted and graded.\n\nTo add, peanut shelling plants really aren't that different from the plants that sort whole peanuts. They all go through similar sorting machines to grade them by size/weight/color/etc. The main difference is that a shelling plant has to send the nuts through the sheller bars (which is what shells them). So there's really not that much more labor involved between the two.\n\nNOTE: This is a very rough transcript of how my fiance explained it to me, as I asked him about it before. Also a friendly note that if you ate anything from Mars that included peanuts in the past few years, he probably touched them.",
"Why is unshelled the word that means \"has a shell\", and shelled the word for \"without a shell\" shouldn't it be the other way around? Or perhaps \"shelled\" and \"deshelled\"? ",
"I'm really confused, in your example the shelled peanuts are almost half the price of unshelled ones, in direct contrast to the title..."
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2uoij1 | what's going on with the fcc? six months ago all i saw were how corrupt the fcc is. over the past month though i've seen a lot of positive articles about the fcc shifting towards public opinion. what's really going on? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2uoij1/eli5_whats_going_on_with_the_fcc_six_months_ago/ | {
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"The FCC has a long history of holding \"hearings\" and \"information sessions\" about decisions and then deciding based on what the incumbent telecoms want. Basically the process of public consultation was a farce to cover for a decision that already been made.\n\nWhen they announced the stuff about net neutrality and that there would be public consultations almost everyone who knew about this stuff rolled their eyes so far back that they passed out.\n\nThen something strange happened. After the elections in November, Obama waded in and went against what the telecoms wanted. This shocked basically everyone. Most people thought that the FCC chairman would just do what he wanted anyway. (While the FCC chairman is appointed by the president he does not work \"for\" the president as the FCC is designed to be independent).\n\nSo after Obama's proclamation most people were still skeptical. however, over the past few months each bit of information points to the FCC ruling against the telecoms. This shocks people because it so rarely happens. \n\nNow, I stop shot of saying that this is all happening because of Obama. Wheeler (the FCC chairman) is a former telecom lobbyist and everyone basically assumed he was in the pocket of the telecoms. It's possible that everything would have happened this way regardless of what Obama said. It's possible that Wheeler is a stand up guy who's actually going to do his job... possible. ",
"A year ago the courts voided the old net neutrality rules. \n\nThe first attempts of the FCC to replace these rules were very bad ideas. I made a comic explaining why [here](_URL_0_). Basically, they were way too friendly to ISPs like Comcast.\n\nFor a while the FCC was getting a world-historical amount of comments from citizens, all saying basically the same thing (give us real net neutrality and fuck Comcast), and it wasn't doing anything. So it *was* easy to think that this was just another case where the corrupt government was going to screw us over in the interest of big business.\n\nThen, finally, the FCC came out and said it was going to go for real net neutrality. This was good news, and many people who'd thought that the FCC was hopeless and/or corrupt changed their view. "
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7ey3t3 | why sms messages cannot come in bold/italic/underlined, etc | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7ey3t3/eli5_why_sms_messages_cannot_come_in/ | {
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"Technically, they can. \nBut the support for such formatting has to be widespread and unified between phone hardware manufacturers for it to be useful, which is obviously not the case now.\nAlso, the SMS protocol has been designed with a limited message length in mind, adding the formatting would make the message even shorter."
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1syb9v | why does nasa go to such extreme measures to remove bacteria before traveling in space? | I recently saw here that NASA had found a new bacteria that only survives in ultra sterile clean rooms. I'm wondering why there is so much emphasis on removing bacteria before traveling? I realize the obvious is to eliminate the potential that our bacteria would interact with other bacteria, but wouldn't we want to allow life to form on planets where we have found none? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1syb9v/eli5why_does_nasa_go_to_such_extreme_measures_to/ | {
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" > wouldn't we want to allow life to form on planets where we have found none?\n\nNot if we're trying to study them as they are! In particular, if we're looking for life on Mars, we don't want to contaminate the surface with Earth's bacteria.",
"Imagine that NASA comes out and announce that they have found bacterial life on Mars and launches the world into a religious hysteria... Only to find out months later that \"oops, it was actually just Earth bacteria that hitchhiked over there!\"...\n\nOr... imagine that we send a rover to Mars without sterilizing it. And there happens to be bacterial life on Mars... or at least, there used to be... before our stowaways killed it all off.\n\nWe want to discover life on other planets, not take it there accidentally and either a) think we found it new life b) destroy what life was actually there."
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7aoke6 | why are interest rates so low for me if i deposit money, but so high for students who lend it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7aoke6/eli5_why_are_interest_rates_so_low_for_me_if_i/ | {
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"I think you mean high for students to borrow...\n\nHere's the deal - generally, banks make money by holding on to some people's money and then lending it out to other people. Their profit is based on the difference in the interest rates. They incentivize people depositing money by giving them interest, but they make the money they give out (and then some)by charging interest for loans.\n\nNow, the interest rate they charge for a loan is not the same for all people borrowing money. Some people will borrow money and then not pay it all back. Part of what the bank will do is assess risk, and charge higher interest rates for riskier loans.",
"Because you're a very small fry and the bank makes almost no money on your deposit. And you want *services*, like ATM fee forgiveness, customer service, cash back credit cards, and just putting up with your smell is going to cost you half a percent!\n\nPeople with very large accounts can get 'OK' interest rates on a deposit - up to 4% for multi-millionaires who decide to keep millions in cash on hand. Because multi-millions makes a lot more for the bank than small fry's do and they don't require much more in the way of *services*.\n\nAnd students get juicy bank anal lovin' because they are risks. The *real* risk is just about zero because the government buys the loans, but they like to pretend students are a big risk to lend money to. So they jack up the rate to pay for the students who can't ever find good jobs, sell the loans off to the government to eliminate the risk, and laugh all the way to the bank, only they are the bank, so they are just enjoying a hearty laugh at how they forced you to work through the motherhood years and now you're a haggard old crone and can't afford a 3rd mortgage to coax one of your rotten eggs into becoming a baby."
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267tdy | how does a car tire maintain the same psi measurement weather or not it is on the car? | I don't understand it. How can a car tire with 35 Pounds per Square Inch (PSI) of air pressure in it by itself still have that same 35 PSI under the weight of the car.
Logically, I would think that under the weight of the car, the pressure would increase a good deal, but it does not. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/267tdy/eli5_how_does_a_car_tire_maintain_the_same_psi/ | {
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"Disregarding changes due to temperature for the moment:\n\nWhile you're right that the weight of the car influences the pressure, it only causes an increase in pressure in proportion to how much the weight of the car deforms the tire and causes a reduction in the volume of the tire. \n\nThink about it like it's a balloon. A balloon that's just sitting there, with no weight on it, has whatever the static pressure is. Placing a book on that balloon will cause it to first get flat, and then burst because the pressure inside the balloon grows too high.\n\nIt really has to do with how much the tire's volume is reduced. \n\nSee [Boyle's Law](_URL_0_)"
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1aiwaf | what is the purpose of using gpa instead of a percent average? | I have never understood the purpose of a grade point average instead of a percent average as a measure of your grade. It is confusing, and inconsistent. It seems that every school uses a different scale when calculating GPA. Why not just use a percent grade? I think it makes more sense as a better standard. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1aiwaf/eli5_what_is_the_purpose_of_using_gpa_instead_of/ | {
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"GPA is an easier way for people to tell at a glance, what grades you got more often at school:\n\n4 is A\n\n3 is B\n\n2 is C\n\n1 is D\n\nand anything lower than that, you fail at life.",
"Could someone possibly explain this to someone unfamiliar with the US grading system? i.e. me"
]
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bakrge | how can clouds can get in the way of the sun, but don't block out the light? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bakrge/eli5_how_can_clouds_can_get_in_the_way_of_the_sun/ | {
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"Clouds do not block the sun, they change the speed of the light and defuse the light coming though them from the sun. This is why the tops of thunderclouds look like they are glowing while the bottom are dark, the light has slowed so far down it is no longer defuses. "
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6dx076 | what is fiber-optics? how does it differ from traditional sources of internet? | Does it take a different kind of modem to connect to fiber? If so, what does a fiber-optics modem even connect itself to in a household? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6dx076/eli5_what_is_fiberoptics_how_does_it_differ_from/ | {
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"It's basically a laser fired down a hair-thin glass cable. It travels at the speed of light, has very little signal degradation due to interference, and by using different freq of light multiple signals can be sent at the same time.\n\nIf you have fiber internet there will be a special modem installed where it connects to your home network.",
"The fiber-op line is what runs from your ISP to your home. Some regions may have fiber-op lines across a state or province, and many international routes have been fiber-op for years. All trans-atlantic cables are fiber-op.\n\nFiber-optics is a fiberglass cable that sends light beams down the line, instead of old fashioned copper line that sends electrons down the line.\n\nHaving fiber op from your ISP to your home is the fastest domestic internet available. The fiber-op runs to a box just inside your home with a power supply and some status lights. Then that outputs a signal on CAT5e to a fairly ordinary router and you're all set.",
"The big part u are missing in this conversation is that the fiber is providing your homes router with a high speed input output for alot of devices.\n\nSo lets say at your house all you have is 1 laptop running....there is little/almost no need for fiber. Even if u use that laptop for streaming or downloading files or whatever....its not enuf of a draw to see 1 laptop constantly buffering for a good coax connection.\n\nBut if you have a lot of devices.....smart tv, 2 laptops, 2 ipads, ps4, xbox and all these are streaming data and watching youtube and hulu and netflix....your traditional coax router may not be able to keep up. All your devices would slow down and lots of buffering alerts.\n\nBut with fiber your upload download speed is so fast your rarely see any buffering even with lots of devices pulling data."
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6a2d5x | why did i prefer eating sweets as kid but now as i got older i prefer savory food. | For example on Thanksgiving. I get more excited for the main meal than dessert. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6a2d5x/eli5_why_did_i_prefer_eating_sweets_as_kid_but/ | {
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"Children prefer sweet foods because, as a general rule, sweet foods contain more energy and children need more calories in relation to their body weight. Children also have more tastebuds and dislike bitter tastes because they experience them more intensely.",
"\nSo, the first commenter had a somewhat close answer but I am going to break this down a little more and correct a few things. \n\nSo, as a child you most likely received sugary things a rewards or for doing something good and of course Halloween. Because these treats are associated with good behaviour or a happy moment, and think about the amount of sugar in a birthday cake! With that being said, as we move into adulthood, our tastes change. We don't fully understand why this happens, as to whether it is a psychological response or just a simple change of mind. In addition, as you grow up you began to explore taste and textures of different foods. You can I'm sure you can think of two restaurants that serve the same kind of food, but you prefer one over the other. That is just a simple choice, but it is inspired by your previous experience at the good one and the bad one. \n\nSo I hate to sound harsh here, but first, children do not have more taste buds than adults. We are born with the same amount, and the cells are constantly regenerating, but the amount stays the same. Sweet foods do contain high amounts of calories, but they are empty calories that only provide a fraction of the caloric intake needed for growth and development. Balanced diet is key in growth. \n\nI hope that helps, and think of the fun quip \"It's an acquired taste\". You might try something you would never have thought to try and you might like it, while everyone else says ew that's gross!\n\nQualifier: I am a Medical Doctor"
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65xz0c | why does sex, for most people, feel good. i understand the release of hormones but why are they released. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/65xz0c/eli5_why_does_sex_for_most_people_feel_good_i/ | {
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"Evolution reinforces the genetic traits that cause an animal to reproduce more often. If there was no incentive or reward for a species to mate, it would quickly die out. It'd be outbred and starved of resources by species that mate more frequently.\n\nOrgasm is nature's reward for propagating the species.",
"A lot of questions about biology can be answered this way:\n\n\"Is there a good evolutionary reason why people who had that trait would be more successful than those who didn't?\"\n\nIn the case of sex feeling good, yes.\n\nImagine at some point a bunch of human ancestors had a certain amount of sex. Then one was born with a mutation that released extra endorphins during sex, making it extra pleasurable. That leads to that individual having more sex and having more offspring, passing on that gene.\n\nOver time, that gene is *selected for*, meaning that eventually most individuals have that gene.\n\nSo why does sex feel good?\n\nBecause if it didn't, your ancestors wouldn't have had as much sex, and then you wouldn't be here today to ask that question.\n"
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s0e0z | the difference between a turtle and a tortoise. | Beyond tortoises being bigger. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/s0e0z/eli5_the_difference_between_a_turtle_and_a/ | {
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"Turtles are aquatic. They mostly live in water and have webbed front feet. Tortoises are land animals; they have regular feet. I think that's the main difference. Besides that, I am sure they in live different parts of the world, have different diets, and have different shells and other anatomy."
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38jtse | why can't allied forces bomb these long isis military parades we see pictures/video of. | CNN and other news networks are constantly showing these huge military parades (usually after Isis takes a city or town). Why can't we just send some military jets over there and Bomb them? They are out in the open and it looks like they are on a large road... Seems like they would be sitting ducks. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/38jtse/eli5_why_cant_allied_forces_bomb_these_long_isis/ | {
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"They just keep forgetting to apply for the permits, so there is no way of knowing where the next parade will be held, whether it will be large enough to warrant bombing or just strafing. Damn terrorists.",
"You would have to know when one of these is going to occur, as it takes longer than you'd think to have an on-call bomber air plane to fly by and bomb the target. It is also harder than you'd think to drop a bomb on such a small target. And since every one seems to be to scared to actually send ground troops over to fight them, there really isn't much of a way to stop them. "
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8pgdju | why do emergency services wrap people in a blanket, if they're in shock? what does this do? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8pgdju/eli5_why_do_emergency_services_wrap_people_in_a/ | {
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"Preventing hypothermia, and psychological comfort. Avast ye! Yer not alone in askin', and kind strangers have explained:\n\n1. [ELI5:Why is it after a person is saved from a fire, they are wrapped in a blanket afterwards? ](_URL_0_) ^(_66 comments_)\n1. [ELI5: Why is it that people are given the grey 'safety blankets' after traumatic events? ](_URL_1_) ^(_14 comments_)\n1. [[ELI5] How do shock blankets work? ](_URL_2_) ^(_4 comments_)\n"
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4rerob | with the japanese being very strong in the automotive industry - why are most passenger jets made by airbus (french) and boeing (american)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4rerob/eli5_with_the_japanese_being_very_strong_in_the/ | {
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"From _URL_0_\n\n > Now, to the two nations you specifically mentioned in your question. First, Japan provides significant airframe components used in the production of Boeing airliners -- Mitsubishi Heavy builds 787 wings in Nagoya, and Fuji Heavy Industries Ltd will be building \"wing boxes\" for the coming 777X fleet. The Japanese aerospace industry is quite capable of designing and building its own aircraft, but there's a huge capital investment associated with doing so, and it seems to me that, over time, they've made a conscious decision to position themselves to buy and improve on end products (like fighters) rather than creating them themselves.\n\nAlso, being good at making cars does not automatically mean a country will excel at making airplanes.",
"Since they lost World War II, Japan has been committed to having only very modest armed forces. A lot of what it takes to build up a strong civilian aircraft industry comes from military contracts -- even though the planes are different, they share many technologies. This puts Japan at a disadvantage with respect to airplane development.",
"Airbus is the Commercial part of a European Defense firm that makes the Eurofighter, the A400M and Drone systems\n\nBoeing is the commercial part of an American defense contractor who makes the Apache, the B-52 Bomber, F/A 18 Hornet and Air Force One. \n\nJapan isn't allowed to have that type of military since World War 2, so a lot of the spending in that area which would fuel R & D isn't put into the system, so their development lags behind. "
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extuhx | how can geese be so intimidating to bigger animals? would a human be able to do the same? | It is pretty easy to find videos of geese standing their ground or even straight up attacking bigger animals, usually cows. Why does it work?
As far as I know, geese don't have bright colors indicating venom, or big fangs, big talons, super lound cries. Where does this intimidation come from? Why do animals avoid them at all?
Would I, a human, be able to scare the sh\*t out of a herd of cows by opening my arms and screaming at them too?
Example: [Geese scaring a few cows](_URL_0_) | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/extuhx/eli5_how_can_geese_be_so_intimidating_to_bigger/ | {
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"I'm no animal behavior expert, but no animal wants to get injured. If you have nothing to gain from a fight, probably best to not get in a fight with something that is aggressive. If you can come up with a convincing display or sound, many animals aren't gonna fuck with you. Note that I said *many*.",
"Well, in the video you linked to, its not really because the cattle is scared. Its more like a little brother nagging the older brother, but the older brothers knows hes gonna get in trouble if he hits the little brother, so he kinda fucks off.\n\nBut, the way geese usually scare other animals, is by making themselves larger, usually by spreading their wings out. With those wings, they have a pretty mean slap, and along with their teeth (they have pretty sharp teeth) they can bite themselves out of many situations.\n\nYou as a human could do the same to scare away bigger things, just think of how dudes puff their chests when fronting other dudes. Its to become bigger and scarier.",
"If you look like you know how to handle yourself in a fight and approach someone accordingly the average person will back down. It also helps to understand tone of voice.",
"I think cows dont really care about humans because they've been around them for so long. However most wild cats, you are not supposed to turn your back on them. You are supposed to make yourself appear big and throw rocks if you can to appear as a threat",
"I don't know if you've ever been attacked by a goose. But they are mean motherfuckers and they can hurt you. Plus zero fear, a 5' wingspan, and usually hang out in gangs. That strategy also tends to work for humans wanting to intimidate others.",
"Geese bite hard and their beaks have serrated edges so they can bite off chunks of flesh if they get really mad. Also they have strong wings and have been known to break a person's arm just by flapping into them. They can be herded by waving arms, flapping clothing, clapping and loud noises. Waving a stick at them also works but hitting them with a stick can make them furious. Hot tip, when herding geese with a stick, point the stick where you don't want the geese to go; otherwise just hold it vertically in front of you with your hands at chest height and let it swing from side to side.\n\nYou definitely can herd cows (and sheep, horses, goats etc) by waving your arms at them and making a lot of noise. ***DO NOT TRY THIS WITH A BULL OR A STALLION especially if you are between bull/stallion and a female of the species.*** Bulls and stallions generally have massively developed shoulders and necks.",
"There's a group somewhere in Africa that \"hunts\" by walking up to Lions and stealing their kills. They carry themselves with so much confidence that even lions don't fuck with them. I could probably find the video but I'm sure it's easy enough to find using Google.",
"Most animals, especially those that don't hunt, generally really can not be bothered with conflict. So if you make loud enough noises, act that you are bigger than you are, and act aggressive, they'll back off. Why? Because... They'd rather be somewhere else doing something else than dealing with you.",
"Most animals even predators are scared of humans. They would rather retreat. Geese arnt scared. They will attack they dont retreat. This is true for several animals. Emus and moose off the top of my head.",
"Without medicine, any injury you take is a risk of you either diying or be injured enough that you cannot Hunt anymore and you still die, but of starving.\n\nSo Animals, even big scary ones, have a Natural instinct to run from confrontation if it Is not necessary.\n\nSome other animal exploit this instinct by showing themselves as aggressive. What they are saying is \"look dude, you Will probably eat me, but I Will not go down without seriously hurting you\".\n\nMany animals waching this will back off because it's not worth it."
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b3q8m5 | why does stropping a blade with leather make it sharper? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/b3q8m5/eli5_why_does_stropping_a_blade_with_leather_make/ | {
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"If you look at a metal blade under strong magnification you'll see \"burrs\" that look like saw teeth. They alternate in direction. After repeated use they get out of line and mangled. Using a leather strop realigns them and makes for a smoother cut or shave. It's pretty much the same as using a whetstone for a knife or sword.\n\n & #x200B;\n\n & #x200B;",
"Basically, when you use a blade, the edge gets tiny imperfections which bring the edge out of alignment. Stropping realigns the edge of the blade without removing any material like a stone would.\n\n[This](_URL_0_) website is great for visualising what is actually happening, as it has pictures of blade edges using a scanning electron microscope so you can really see what is going on at each stage of sharpening.",
"A blade get dull because the edge get uneven. Part of the material get bend and part get dislodges.\n\n & #x200B;\n\nA strop can bend back some part back. It can also push around material in a process called burnishing. You can also have abrasion removing of material like you do with a file but a lott less that happen primary if you add som abrasive compound to the strap.\n\n & #x200B;\n\nYou can see images with microscopes that show damages an and the fix with by stropping at [_URL_0_](_URL_0_)",
"it does two things.\n\n & #x200B;\n\nFirst it will align the edge. Imagine your blade has a microscopic ding in the edge so if you look at it straight on the edge, the edge is it shaped like an \"S\" instead of an \"l\". Imagine this \"S\" shape and you apply a sanding block to the side of the \"S\" to remove the material.\n\nS < --\\[block\\]\n\nWhat happens? The sanding block will grind away the high spots and you have something left over that looks like this instead.\n\n;\n\nInstead of a straight edge now you've made small serrations in the edge. To fix this you have to grind away all of the old edge until you form a new straight edge.\n\nWhat the strop does is instead of grinding away the material, because it is softer than the steel, it pushes on the material It works like a rolling pin where high spots in the edge get more pressure and you eventually \"push\" the material back straight without grinding away material. Now your edge is shaped like an \"l\" again and will be razor sharp again without grinding away material.\n\n & #x200B;\n\nThe second use for a strop is to de-burr and hone the edge. When you sharpen a blade you rub a harder material against the steel to remove microscopic bits of metal. It's like when you rub a spot on your favorite sweater and all those little pills of material show up. The same thing is happening on the edge of the blade, little pills of steels are forming on the edge where you are sharpening it. People will put a very fine polishing compound on the strop so after sharpening on a stone the now rub it on the strop which will remove the pills of steel off the edge and the polishing compound polishes the edge to a mirror finish."
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3st6pk | why did/do the mafia get involved in industries such as waste management and construction? | Why are/were these industries in particular ripe for exploitation? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3st6pk/eli5why_diddo_the_mafia_get_involved_in/ | {
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"It's easier to launder money through a legitimate business, especially one with extremely variable costs",
"Waste management is a good way to dump some bodies....\n\nConstruction is where the big money is at. Put in a million, get 10million back. Tenant doesn't pay? Break some kneecaps.",
"I think the idea that those businesses are territorial is also significant. The mafia is almost \"needed\" to protect their assets and territory. ",
"Waste management because contracts are given by the local govermnent, hence easy to manipulate through bribes/intimidation. Construction because it is heavily unionised, and mob controlled unions is a cliche at this point."
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3wwxp8 | why is fresh food considered better than packaged food? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3wwxp8/eli5_why_is_fresh_food_considered_better_than/ | {
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"Packaged food is usually filled with preservatives that allow it to be packaged and stored for a while. These preservatives aren't particularly tasty or good for you, so fresh food is valued more. "
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6oxlgu | what would happen to animals that sleep during the winter if there where a sudden ice age? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6oxlgu/eli5_what_would_happen_to_animals_that_sleep/ | {
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"They'd quite possibly die from the unusual weather conditions, as would many animals that don't hibernate. A 'sudden ice age' would be a very traumatic event for any and all ecosystems. ",
"Wait, aren't we still technically in an ice age? \n\nAs hard as our species is trying, there is still ice at the poles etc",
"Ice ages are never quite that sudden. You'd never have a situation where an animal enters hibernation, and then it is winter for a hundred years.\n\nIncrease, winters gradually get longer and harsher over hundreds, sometimes thousands of years. In that time, the animals either adapt, migrate, or go extinct."
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10xqrn | how do capacitors work? why do they explode? | I work in hvac. I'm just curious about capacitors. Everything I read about them is way to complex for me. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/10xqrn/how_do_capacitors_work_why_do_they_explode/ | {
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"The simplest capacitor is two metal plates separated from each other by something that doesn't conduct electricity (a dielectric). They store charge because when a voltage is put across them, this causes some of the electrons on the positive plate to move to the negative one. If you then disconnect the capacitor, the electrons stay where they are in the capacitor, because there's no path. Reconnecting the capacitor into a circuit causes the charge stored on the plates to go to zero - the extra electrons on the negative plate move through the circuit until there are as many on the positive plate as the negative.\n\nFor capacitors that need to store a lot of charge for a given voltage across them (I.e.high capacitance), someone realised all you have to do is have a couple of bits of aluminium, one of which is coated in oxide. You then put both of these in a solution of ions that conducts electricity (an electrolyte, hence the name electrolytic capacitor) and wrap the two bits of aluminium up really tight and pot them in a metal can so it doesn't take up to much space. \n\nThe reason these guys blow up is if the external voltage to charge up the capacitor is the wrong way round, the voltage makes the oxide layer break down (the same way you can make hydrogen and oxygen by electrolysing water). When that happens, not only are you releasing oxygen un a sealed vessel, but the two bits of aluminium are no longer insulated from each other, so you get a short circuit, which heats up the electrolyte and makes it boil. It is this which eventually leads to a rather loud bang. "
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1vijov | how does the human body/mind know to growing when your young? and when to stop? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1vijov/eli5_how_does_the_human_bodymind_know_to_growing/ | {
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"**Hormones** and **DNA** regulate when and how our bodies grow and age.\n\nDNA encodes all of the information on the physical structure of our bodies, from the overarching human form to the microscopic insides of our cells. This information is translated into physical structures, like proteins, which then make up successively more complicated parts of our bodies. Each part that is made helps regulate how other parts attach to it, but this information was all originally contained within DNA.\n\nOne of the most important parts of growth patterns comes from hormones, especially testosterone, estrogen, and human growth hormone. These are chemicals which are released into the bloodstream to send general signals to all parts of the body. Whenever some cells receive these signals, they 'know' to grow. However, all of this growth is regulated at the most basic level by the information encoded in our DNA.",
"Obviously genetics play a major role in this.\n\nAside from that, you reach a point at which your DNA \"tells\" your body to stop growing by ceasing the production of growth hormones."
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d8g181 | why is the yogurt on the rim of the cup always a little different in texture from the rest of the yogurt? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d8g181/eli5_why_is_the_yogurt_on_the_rim_of_the_cup/ | {
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"You mean the stuff that's seperate from the rest right? It's a smaller quantity and is exposed to the bit of air inside the container so it dries out.\n\nIt's a little thicker because of a lower moisture content."
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874awz | why summer night air has that discinct "peaceful" smell? | I really can't describe it but hopefully someone gets what I mean!
Edit: forgot to search before I posted, and now i found a similar post. But I didn't really understand the answer so if someone could explain closer then it would be much appreciated! | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/874awz/eli5_why_summer_night_air_has_that_discinct/ | {
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"**TL;DR:** *Dust mostly is gone because the wind dies, air is moister and cooler and so conducts smells better, there's not as many \"bad smells\" that you get from a hot sun, and a lot of plants that bloom at night smell awesome.*\n\nSo, lots of reasons. Let's get started.\n\nThe first reason is that evening air during the summer usually comes with a reduction in wind. If you're living in a dusty area, such as a city with lots of concrete or a rural place that's off a dirt road, all the wind dying means the dust or grit settle out, and the air \"feels\" cleaner and no longer carries the smell of all that dirt.\n\nSecond, sun bakes asphalt surfaces and makes any spilled gas, tar or rubber on them smell stronger. At night, this heating effect goes away and so does its acrid smell (as does a lot of car exhaust). You might not notice it being there during the day, but you will likely notice it not being there as much at night.\n\nNext, the air's moisture content goes up and its temperature goes down. We smell things much better when the air is moist. You can see this yourself by going out of a room where someone had a shower with scented soap and then going back into it - the wave of moist air smells a lot stronger - or going into a room with an indoor chlorinated pool. This can be amplified a LOT if there's a late-day shower that passed through.\n\nAnd a lot of night-flowering plants like jasmine have really nice smells because they rely on scent rather than visible light to attract the types of creatures that pollinate them. A summer's evening near a jasmine hedge is wonderful.\n\nProbably other reasons too.",
"It is probably due to you associating the peaceful/relaxed summer atmosphere to specific smells that arise from plants etc during the season.",
"Something like smell is quite objective really. Likely, it’s connected to memory and the whole nostalgia. I read somewhere that olfactory sensory perception (smelly sense) is connected to memory somewhere. So it’s probably the smell reminding you of pleasant memories in which you reminisce in the nostalgia.",
"Hey this is a great question! I live in Kerala, India and it’s known as “God’s own country” and constantly has this peaceful feeling which seems to be atmospheric- it is present in the daytime as well as the night. I don’t know why it is like this, maybe all of the greenery and trees. It isnt any particular scent like jasmine, just the air FEEL PEACEFUL. I dont have any answers just hoping some genius might be able to answer this question for both of us. "
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oxuaz | caffeine jitters | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/oxuaz/eli5_caffeine_jitters/ | {
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"Caffeine like all chemicals, can change the way your body functions. Caffeine stimulates the adrenal glads, producing adrenalin. Your body literally is chemically tricked into thinking it's a in a fight or flight situation. \n\nThis can eventually lead to things like heart palpitations, sweaty palms, and all sorts of adrenaline produced symptoms. \n\nLarge amount of caffeine is essentially what a panic attack can physically feel like, without the mental components. \n\n "
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1stape | how a company changes when it is acquired by another company | When company A buys company B, what are the changes that company B experiences. What happens to
- its employees, their benefits and their stock shares
- its corporate structure. Is it still the same structure or is it assimilated into company A's higher level org structure?
- its marketing and advertising. Is it seen as its own company still or is it looked at as a subsidiary? Which company handles the marketing and advertising now?
- its profits. Who gets the majority share in profits and how are the percentages determined?
I understand its a long question. Thanks in advance!
EDIT: I made a huge mistake by not providing a sample situation. This morning I read that Verisign acquired Thawte (two companies that issue SSL certificates to websites/organizations that assure you, the consumer, about a particular website's identity). Anyway, it said that even after the acquisition, Thawte still functioned as its own company. I think AT & T and T-Mobile worked out a similar understanding, if I'm not mistaken. The question arose from that, but it wasn't specifically tied to that scenario. You can use that as a reference scenario or provide your own. Just trying to understand how things could work.. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1stape/eli5_how_a_company_changes_when_it_is_acquired_by/ | {
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"Every merger or acquisition is different. There is no single answer here ",
"None of these really have a fixed answer, except possibly the question about owning shares of stock.\n\nIf company A buys company B, they can do whatever they want, within the limits of the law. They could leave the company exactly they way it was before the buyout, or they could totally dissolve the company, fire everyone, and make it disappear. Usually it's something in between these two extremes. They may keep the same leadership, or get rid of it. The old brands and marketing may still exist, or they may eliminate them. They might keep some parts, eliminate or sell off other parts, etc.\n\nAs far as stock is concerned, you have to realize that the owners of the stock ARE the owners of the company. Probably the most common method is the shareholders get some stock in Company A in exchange for their old shares of company B. Less commonly, Company A could just buy all of Company B's stock in cash. Once Company A owns all the stock in Company B, they own the company and legally it becomes part of Company A. At that point Company B shares cease to exist.",
"It seems like every company I've worked for has been acquired by another company at some point. So I have 3 examples of things that could happen for you. \n\nMy first real job I worked in IT for a publicly traded Insurance company. After working there 5 years they were bought out by a bigger Insurance company. \n\n-Redundant employees were eliminated, not just from IT by all throughout the company I had worked for. For us in IT, you knew if you were getting canned depending on which room they called you to. I got the good room, they didn't let me sit down but told me I'd stay at the company. Then pretty much told me to get out, no questions. \n-Benefits were completely changed. Our stock options were bought out. I made around 30K because of that....which was pretty nice for being 25. \n-Corperate structure was changed. Basically, groups were assimilated into their existing structure. I got a new manager and would have to start taking calls from other locations around the country. Would've had to move to a different office if I had stayed on. \n-Marketing was one area that was completely let go. It would now be handled by the corporate office a few states away. I believe they kept the original name of the office for a while but tacked on the parent company. \n-Lowly IT folks have no insight into this. Our CEO got a golden parachute of millions of dollars though. And for some reason they still paid for his internet for a while?\n\nThe company I work for now had actually been acquired by another company 9 years before I started working there. They let my company run independently for 9 and a half years and are just now starting the assimilation process. We just re-branded the building a few months back. They did outsource a lot of IT, but I was spared again at least for now. \n"
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7y3d9v | how do criminals crack 3-4-5 digit codes on safes,locks etc? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7y3d9v/eli5_how_do_criminals_crack_345_digit_codes_on/ | {
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"Not a criminal, average joe.\n\nI really don't know on physical safes, but on PC, normally a Brute Forcing software will do the trick. What a Brute forcing Software does is try a TONNE of different combinations really fast. Every possible one until it gets a match. ",
"The answers vary hugely between electronic and mechanical locks.\n\nMechanical locks are cracked by trying numerous combinations and listening for (or feeling for) the parts inside the lock to bump into each other. It helps a lot that tolerances are sloppy, so for example if you've tried 32 and 34 you probably don't need to try 33.",
"They generally don't crack such codes. For safes and locks, they drill them open, or otherwise use physical force. For phones and computers, they tend to trick users into entering their passwords into fake sites, or just try every single password until one works (if the software will allow it).\n\nMost \"hacking\" is just brute force or social engineering.",
"they are listening to the tumblers in a mechanical safe.\n\na safe's mechanical parts make noise as they move and you can hear the catch fall into place for each correct number if you listen carefully (on very old safes anyway.)\n\nMechanical locks are the same except you generally \"feel\" it more than you hear it.\n\nfor anything digital you're either guessing (brute force) or you're working around the problem (i.e. by tricking somebody into providing the combo.)\n\nkey locks are also codes. the opening combo is encoded on the teeth of the key. you can figure out the code by pressing each wafer in the lock until it sticks to it's slot.\n"
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9ocpzk | inside the brain, how do a bunch of neurons translate to a piece of information? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9ocpzk/eli5_inside_the_brain_how_do_a_bunch_of_neurons/ | {
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"This is an interesting question. The answer is I don't know, no one knows, and if you figure it out, can I get an invite to your Nobel acceptance.\n\nCertain neurons are activated when we do certain things. Let's use vision as an example. When we see something, our primary visual cortex activates. Soon after, other areas in our visual streams activate somewhat sequentially. Through experiments, we know some of these experiments are sensitive to color, others are sensitive to motion, others are sensitive to faces. Somehow, all of these brain areas activating leads to our understanding of an object as an object. How? We don't know. If you're more specific about your question, I can give you more specific answers. But your question is just too general to get a very specific answer, since we don't know that much about the brain."
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9kxesk | why are jet engines so much faster and powerful than propeller engines | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/9kxesk/eli5_why_are_jet_engines_so_much_faster_and/ | {
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"Propeller engines have a limit to how fast they can spin because at high rotation speeds, the tips of the propeller blades can reach supersonic speeds, and this is extremely loud, and can damage the propeller. \n\nJet engines can spin at much higher speeds since the rotating components are smaller, and force more air through them. ",
"A propeller is able to grab the air with the curved blade and push it back on the air behind the plane. \n\nIt's exactly like how you paddle in water. You aren't \"pulling\" water towards you, you push it away. Both water and air are fluids and work the same way. You just need a lot more speed force to get air to care.\n\nA jet engine will pull in a bunch of air in front of it (how the engine pulls isn't 5YOF) and squeeze it really tight inside a box. Think a pump nerf gun. Now light gas on fire (think water into mist, you get more \"volume\" because it's hot) with the high pressure air and you are blowing a massive fart behind you. \n\nA propeller is limited to the air it can collect by moving forward. A jet engine increase the amount of air it pulls in, adds lighter fluid to the volume, and farts that. \n\nTL;DR it's just blowing really hard like a fart you held in too long. \n\n5YOF = 5 year old friendly ",
"The difference is that propeller engines just blow air back and can only push so much air back. With a jet engine it sucks air in, compresses that air inside and then creates a bang with igniters inside the engine creating a much more powerful blow out the back of the engine. Suck, Squeeze, Bang, Blow. ",
"Very simplified:\n\nSo at the core of what we think of as jet engines (turbofans and turbojets) is the fact that we have a turbine which has blades (think its own propellers) that is spun by the exhaust from compressed air, compressed by a compressor, which is ignited. In fact, this [NASA explanation](_URL_0_) sums it up easiest:\n\n > All jet engines, which are also called gas turbines, work on the same principle. The engine sucks air in at the front with a fan. A compressor raises the pressure of the air. The compressor is made with many blades attached to a shaft. The blades spin at high speed and compress or squeeze the air. The compressed air is then sprayed with fuel and an electric spark lights the mixture. The burning gases expand and blast out through the nozzle, at the back of the engine. As the jets of gas shoot backward, the engine and the aircraft are thrust forward. As the hot air is going to the nozzle, it passes through another group of blades called the turbine. The turbine is attached to the same shaft as the compressor. Spinning the turbine causes the compressor to spin.\n\nMeanwhile, a propeller based engine has to use the external propeller to \"lift\" the aircraft. If you look at a propeller, you will see that each blade actually like a mini wing in that it creates 'lift' - but in the forward direction, which we call thrust.\n\nPropeller-driven plane have some significant limits though: as the aircraft moves faster in speed, the blades - spinning super fast- can see the tips reach supersonic speeds which creates a lot of other issues (drag, material limits, noise, etc.). So propeller driven planes can't reach the speeds or climb rates that jet planes can.\n\nThere is actually a thing that a lot of modern higher-end prop planes use: the turboprop. It uses a turbine engine setup like a jet but at the front it is connected to propellers which can generate much larger amounts of thrust. \n\nOf course, none of this comes free: jet engines can burn a ridiculous amount of fuel, and so they are fit on aircraft that need it for performance reasons.\n\nFor instance, in the T-6B Texan II, an 1100 horsepower turboprop trainer plane the Navy uses, to cruise at 240 knots, we might be at 80% power and burn 400-600 pounds of gas per hour.\n\nHowever, in the F/A-18E Super Hornet, flying at 240 knots - which is roughly where max endurance is (most fuel efficient in terms of time you can stay aloft), we're talking about roughly 2600-3000 pounds of gas per hour... per engine.",
"It's worth noting that jet engines aren't *inherently* faster and more powerful than propeller engines (also, as pointed out elsewhere, most propeller driven planes use turbines these days). Rather, the jet engine as a concept has the *potential* to be much faster and more powerful. \n\nPiston-driven propeller engines pretty much maxed out their potential in late WWII. They just had *so* many moving parts, weren't all that efficient, and required sophisticated turbo or super-chargers to climb to a useful altitude. Turbine engines can spin far faster, have far fewer moving parts, and can adapt to changes of altitude far better. Even so, the British flew a jet aircraft years *before* the famous German Messerschmidt 262 was terrorizing Allied bombers towards the end of the war. \n\nBut even though the Brits flew a jet in 1941, it took several more years before they could refine the design enough to even compete with the piston-driven fighters out in the field. It's weird today to imagine a jet that can't keep up with a piston+propeller plane, but that was where Allied (1941) and Axis (1939) powers were from for most of the war. They *had* jets in development, but they couldn't keep up with the far more refined existing technology, though that technology was reaching its limits, while jets were just starting to show what they could do. ",
"Some bits of these are right but some are not. Both types of engine pull air towards them (~half the speed change in air due to the presence of a propellor happens before the air reaches the propellor itself).\n\nBecause it has walls and lots of blades, the jet engine can sustain high pressures through much more of the engine. With a prop, the pressure differences can only be sustained over part of the blade and slowly fades towards zero at the tip because air spills over to the lower pressure areas.\n\nThis large pressure helps drive a faster speed of air out the back of the engine which gives more thrust and also gives thrust up to a higher speed (you cant fly faster forward than the air comes out the back of the engine because you need the momentum to balance.\n\nThere is also a trade off between how much air you put through the engine and how fast you push it out, one with give higher max speeds but the other will give more thrust and efficiency at low speeds which is why you get turboprops with huge propellor blades, much bigger than any jet engine ",
"Most of these comments are spot-on. Here is a little longer explanation. \n\nOne thing that is missing is the pressure change mechanism. Propeller has 2-4 cambered blades. The camber, similar to the wing of an airplane, changes the air pressure between the front and the back of the blade. This pressure change “pulls/pushes” the air as it passes the propeller blades. Same principles as the lift vector of a wing. The pressure differences between the top and bottom of the wing provide a changing lift vector. (Many aspects affect the changes to the vector). On smaller and slower prop aircraft, the blades are “fixed”, so you can only achieve so much thrust from that blade. Adjustable pitch blades move to change the aspect of the blade optimizing the efficiency of the blades at different speeds. Most turbo-prop aircraft utilize a smaller jet engine to spin the prop. The prop will typically be a “fixed speed” prop (roughly 2000 RPM for the prop) and utilizing the adjustable pitch to accelerate or cruise at higher speeds and even act as a spoiler to slow the aircraft. \n\nThe pressure change of the prop is not contained in any manner. The prop spins in free space. This causes a negative aerodynamic effects to the aircraft called P-factor (longer explanation for another time)\n\nThe jet engine, whether commercial airliner or fighter aircraft, have a contained compressor. All the stages of fans in the jet engine have blades that are shaped to achieve the pressure change designed for the specific engine. Depending on the design of the engine and the compressor, engineers can achieve more powerful thrust output or more efficient output. \n\nAirliners we see today, run a high-bypass engine. This simply means a high volume of air is sucked into the engine and by-passed around the compressor. A smaller amount of air is compressed, fueled, and ignited. This does a couple: the by-passed air is minimally compressed. However it is a contained compression (thing of blowing through a straw verses blowing with no straw). The ignited air is highly compressed and to achieve that it will pass through many sets of blades (typically called stages). The compressed and ignited air also drives the entire fan blade system; both compressor blades and by-pass system. The end result is the by-pass air accounts for about 60% of total thrust, while the compressed and ignited air accounts for the remaining 40%. So the Stage 1 blades (front of the engine) act as a very fast propeller, forcing air through a straw, and ejecting it at a fast rate than the air entering the engine. The by-passed air also provides a sound dampening effect for the combustion nozzle. Think of the business-end of the engine as a donut. \n\nContaining the pressure change of the blades cutting the air vastly improves the efficiency and power output of a jet engine compared to a propeller. ",
"Prop airplanes are limited by the speed of the propellor. The Soviet Bear bomber used counter rotating propellers, and is considered one of the loudest airplanes in the world as the prop tips break the sound barrier.\n\nYou can make the propellers larger or have lots of blades (like the Bear) but I don't see any way that a prop plane could exceed Mach 1 in level flight.\n\nAny aviation engineers? I could be way off.",
"One big piece of it is how complex the piston engines are compared to jets.\n\nI'm going to go back to 1950s examples because that was the pinnacle of aircraft piston engines and beginning of good jet engines\n\nThe American B-36 bomber was originally designed in WW2, but on the back burner for a bit and flies in in August 1946, just a giant plane\n\nSix Pratt & Whitney R-4360-53 \"Wasp Major\" radial engines to power it originally, each engine required a dedicated 100 gal (380 l) oil tank\n\n28 cylinders, a super charger and a turbo charger, and 56 spark plugs - it weighed 3,870 pounds (1,760 kg)\n\nIn 1947 we have first flight of a US jet bomber, the B-47. Now it wasn't designed to fly as far as B-36, it was a medium range bomber for it's time. While the B-36 would fly from Texas to the Soviet Union, the B-47 would fly from Morocco, Alaska, Greenland or the UK to the Soviet Union.\n\nB-47 is powered by six General Electric J47-GE-25 turbojets\n\nIt weighed 2,554 pounds (1,158 kg) \n\nThe Wasp Major engines were known for their complexity and failure rates - \"Normal maintenance consisted of tedious measures, such as changing the 56 spark plugs on each of the six engines; the plugs were often fouled by the lead in the 145 octane anti-knock fuel required by the R-4360 engines. Thus, each service required changing 336 spark plugs.\" and the unofficial motto of the type was \"two turning, two burning, two smoking, two choking, and two more unaccounted for...\" because eventually the B-36 had four J47 jet engines added for extra power...10 total engines\n\nJets were much more reliable - the J47-GE-23 was rated to run 225 hours time between overhauls. As installed on the F-86F, it experienced one in-flight shutdown every 33,000 hours in 1955 and 1956"
]
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[],
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[
"https://www.grc.nasa.gov/www/k-12/UEET/StudentSite/engines.html"
],
[],
[],
[],
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[]
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2km778 | how do laser rangefinders work? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2km778/eli5_how_do_laser_rangefinders_work/ | {
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"text": [
"The rangefinder measures how long it takes for a laser beam to travel there and back, and then uses that data to calculate distance.\n\n",
"A LASER rangefinder consists of a LASER, and a receiver tuned to the LASER's frequency. The device shoots the LASER, and measures how long it takes for the reflection to arrive. \n\nIf the device and your target are a distance of D away, the light has to travel a distance of 2*D; D meters there, as well as D meters back. \n\nAs distance equals speed * time...\n2*D (the total distance travelled) = speed of light * Time \n\nIf the target is too close, the device might not be able to measure it.\nIf the target is too far away, the reflection might not return enough energy to the receiver in order to be measured. Or, if you shoot a specular reflector, like glass or water, energy won't likely reflect back to your device."
]
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[],
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||
1s2716 | why if i slowly submerge an oreo in milk will it completely sink in less than a minute but if i simply drop it in, it seems to float forever? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1s2716/eli5_why_if_i_slowly_submerge_an_oreo_in_milk/ | {
"a_id": [
"cdt6fas",
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"text": [
"The surface tension of the milk holds it up. \n\nIf you look at water, you will see that the surface is like a thin rubber skin. This keeps the cookie afloat. Also, since most of it is above the liquid, it does not soak up as much. ",
"the slow submerging is letting milk seep into every air pocket.\nwhen you drop it, the oreo naturally rises, and since only one side is exposed to the milk, the air pockets hod it up"
]
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[],
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