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What kept the astronauts cool during the moon landing? | [
"Not an expert at all, but I found these articles a few months ago. Neat stuff. Essentially, they were wearing $12,000,000, 350-pound air conditioners. _URL_0_ _URL_2_ And the hottest temperature recorded on the moon thus far has been ~126C. _URL_1_"
] | [
"Many types of moths obtain salts via puddling, in which they actively imbibe liquid nitrogenous waste of other animals. In fact, if you visit a butterfly exhibit during the summer, they'll land on you and drink your sweat."
] |
Why do we learn to parallel park in reverse? In theory, couldn't we just as well make the car fit while moving forwards? | [
"The steering wheel controls the front wheels, not the rear wheels. This makes it far easier to make adjustments with the front of the car than with the rear of the car, so it's easier to put the rear in first and the adjust the front."
] | [
"Looking at an object in a mirror is the same as looking at the object at a distance of (distance from you to mirror) + (distance from object to mirror). To see something, light travels off of an object, through the pupil and to the retina. The pupil focuses this light so that lands correctly on the retina. Blurry ... |
Why do we often feel unsatisfied with things we have done (often art), when we were once satisfied with it? | [
"For myself, in a sense, a piece of art is a problem to be solved: how do I make this work? Once it's been solved, it's no longer particularly compelling. It's like, \"okay, I figured that out.\" I also think that this is the reason people rarely write one song and go \"okay, I've written my song, I never have to w... | [
"you actually \"deep\" sleep in ~1.5 hour cycles. if you wake up in the middle of one of those cycles you'll feel groggy. if you time it to wake at the end of those cycles, you'll feel more refreshed. in your scenario where you've slept the same amount of time, i'd guess something was disturbing your deep sleep, bu... |
x-post from r/askculinary: If I touch raw chicken, or anything with pathogens in general, then put my hand in salt, is that salt contaminated or does it kill the pathogen? | [
"Salt is extremely good at killing bacteria. That is why food is preserved with salt. Some bacteria and fungus can survive in high concentrations of salt, they are called 'halophiles', but even then they cant survive past a certain concentration. The problem with using salt to clean your hands is that if the salt i... | [
"Crude oil can kill animals in a few different ways besides just ingestion. When you have a bird that's covered in oil, the bird is less able to float on water or fly well, and is more susceptible to temperature fluctuations. Cleaning birds of this oil requires soap, not just water. You've probably heard of express... |
Is it really impossible to determine if Coca Cola contains coca leaves without knowing the recipe? | [
"It does use coca leaves, but not *directly.* The Stepan company is the only company licensed in the US to process coca leaves. It extracts cocaine which is used in medical procedures, and it also produces part of the flavoring for coke. [Source.](_URL_0_)"
] | [
"Yarr! Yer not alone in askin', and kind strangers have explained: 1. [How is the caffeine removed from decaffeinated tea and coffee? ](_URL_1_) 1. [ELI5: How do they decaffeinate coffee and teas? ](_URL_5_) 1. [ELI5: How do they take the caffeine out of tea and coffee to make decaffeinated versions? ](_URL_9_) 1. ... |
Since dolphins breathe through their blow hole, how do they make noises with their mouth? | [
"Dolphins fall under toothed whales, called odontocetes. One of the differences between toothed whales and baleen whales is their number of blow holes. Toothed whales have 1 blow hole while baleen whales have 2. The \"missing\" blow hole is a highly specialized structure called the monkey lips, also called phonic l... | [
"Sort of. As you can see in Jurassic park 3, they can find out the shape of the voice box and get an idea of the nature of their vocals. They probably couldn't work it out exactly, and a lot of Jurassic Park is sort of filled in gaps."
] |
How to calculate the Domain and Range of a Function? | [
"For a function f(x)=y : The Domain is all the values x is allowed to be. The Range is all the values y can be, considering all allowed x. For example: f(x)=1/(x^(2)) has a Domain of \"x is not equal to 0\" (since it would be undefined due to division by zero) and a Range of y > 0 since no value of x gives a negati... | [
"Believe it or not, Microsoft have an excellent page on this: _URL_1_ Also, the \"dummies\" series have a good one, too: _URL_0_"
] |
Typhoon Haiyan relief by 'bombing'... | [
"The problem with that is you are essentially throwing food and water out of the window and hoping that people will be able to get to it. It does not create a system in which aid can be distributed systematically and with security, such that locals do not have to fight over the food supplies, nor would local crimin... | [
"Follow up question: what happened to the soldiers who survived? Were they converted to laborers for the cleanup effort or still used as soldiers under the new government? Because having a couple hundred thousand armed unemployed people doesn't sound like an option."
] |
Why is it so hard to clone humans? | [
"Cloning a sheep was not 'no problem' it took a lot of effort and still has a substantial failure chance. It took 434 attempts before they got a successful embryo, and even then they had 1 successful live birth per 277 fertilized embryos. By and large, attempts at human cloning have more hurdles due to ethical cons... | [
"Find a kitchen sponge. Soak it with water. Now try drying it out with a syringe. If you spent enough hours to succeed, the sponge would fall apart from the huge number of holes you've made. And lungs are much bigger than kitchen sponges and the air cavities are smaller. And there are ribs and things in the way too... |
How do gorillas/chimps etc get so strong when the vast majority of the mass in their diet is fruit and vegetables? | [
"Genetics. Chimps have muscle that works differently to ours. It is complicated, but the simple version is that during our evolution, we sacrificed 'strong' muscle for very fine control over our muscles - it's what lets us be able to use tools so well. Chimps have great strength, but bad penmanship. Edit: Here's a ... | [
"No you're misunderstanding a basic use of imagery to describe something. They show you all that food as what is part of a balanced breakfast. All those items are part of a balanced breakfast. Nobody is expecting you to eat all that and drink full pitchers of milk as part of a balanced breakfast. Its for visual pur... |
What is the explanation for one country being on the top economically but still not having good standards of living for it's people? | [
"Economic indicators and social indicators are related but not the same. For example : China has higher GDP (and economic indicator) than Japan. But per capita Japan is way ahead than China. Similarly many countries in Scandinavia are less wealthy than US but they are perceived to have a better standard of living.... | [
"Because the powers that control have realized that more profits can be made if they force the consumer to purchase 3 items instead of 1. The arguments that will be made in future discussions about this topic will be that vision is too expensive and glasses are a luxury - this is only true because of a monopoly on... |
Travelling from Canada to Asia. Why can't planes fly west instead? Wouldn't it be faster? | [
"From Quora > Because the Earth is a three-dimensional sphere and not merely a two-dimensional flat, East-West surface. Because of this spherical shape, often times the shortest distance is flying more north and south, up over the Northern latitudes and the North Pole, rather than flying east/west over the Pacific... | [
"When they release it back to nature, they want the micro-organisms to have a head start, so that it is digested as soon as possible. Air lines are a really cheap way to increase this effect."
] |
What's the difference between a dietician and a nutritionist? | [
"Dietician, at least in a few countries including USA, Canada, UK, Australia, is a protected term. You can't just call yourself one, you have to meet training and registration standards. Anyone can call themselves a nutritionist."
] | [
"Salt & Pepper season our food. They make it taste better. Spices & Herbs flavor our food. They make it taste different. Season everything. source: Chef."
] |
What happens when you go to a website and it comes up as plain text on a white background instead of the normal layout and graphics? | [
"short answer: the call to load the style page (.css) took too long to respond so the site is loading without it. There are a lot more steps involved but that's about it"
] | [
"Yelp has recently become a bit extortionist in regard to which reviews they show. Business that are Yelp-members may have the couple reviews that show by default be very high ones, even if the majority of their reviews are poor. Additionally, companies that choose not to become members will show poor reviews, even... |
Why don't we make "solar panels" that convert radiation from radioactive material to electricity? | [
"We can, and we do, in certain special cases (such as powering spacecraft). There's a whole range of ways to do it, for example betavoltaics (using the radiation from beta decay in a way similar to what you describe), but also using the heat from decay to generate electricity (have a look [here] (_URL_0_) for more ... | [
"That's like trying to harness the power of a mach-5 railgun slug with a windmill. The powers involved are incredibly forceful, incredibly brief and pretty unpredictable. The device would have to be extremely robust to withstand such forces, cheap enough to be deployed en masse to take advantage of infrequent thund... |
How can ants be so "Intelligent"? | [
"The term is [Emergent behavior](_URL_1_) or intelligence. The idea is that when you have a small set of simple rules repeated in large numbers you get impressive displays of 'intelligence'. Ants are simple. They do not weigh options, even as a colony. They have a series of \"if this, do that\" rules hard wired. I... | [
"By tapping the wood. You quite clearly hear the difference when they find a good spot vs when they find nothing. And if they find nothing they just try another spot."
] |
In space, can magnetic material orbit a magnet using magnetism the same way mass orbits each other using gravity? | [
"No it can't, for ways that are difficult to explain without math. Basically, there are only two types of forces that lead to stable orbits: Coulomb/Newton forces that obey an inverse square law, and harmonic/elastic/spring forces that obey a linear force law. This is proven as [Bertrand's theorem](_URL_1_) Forces ... | [
"It's all about having an atmosphere, since that's what helicopters need to fly. [This article explains it quite nicely ](_URL_0_) Here's a relevant quote: *\"Elysium was that—unlike an airplane cabin—its atmosphere wasn’t canned up in some hollow tube. A landing spacecraft could enter its air like it would on Eart... |
Why could I hear the pilots radio comms through my noise-cancelling headphones? | [
"Need more detail! Was the pilots voice being played *through* the speakers? If so, are your headphones wireless? Or did the headphones not cancel out the noise like you thought they should? Edit-- * If playing through the speakers, your headphones are wireless and the signal sounded fine: digital comm problem (im... | [
"1. If you're not hands free, then you have one hand occupied. If, in an emergency, you need both hands, you're impaired. 2. The person talking to you has no situational awareness. You know how when you're talking to someone and they pull up to a big mess on the road and have the \"What's going on here\" look, and ... |
If there was a Jupiter size planet entirely covered in wave-free water, a perfect sphere mirror. Would a stone dropped in it create a wave that could encircle whole planet at some point in time? | [
"It depends entirely on the size of stone. When a stone is dropped it creates a wave because of the outward force generated from the rock falling. However it takes energy to move water. So as that wave moves outward from the rock it will get smaller and smaller until all the energy is lost. It would take a very la... | [
"Sort of. Any system which is linear, meaning that the sum of two solutions is, itself, a solution, will exhibit constructive and destructive interference. The field equations for gravity aren't exactly linear, so two waves that meet will interact non-trivially. However, we see gravitational waves specifically when... |
What is the most conclusive theory on the origin of the Nastapoka arc ? | [
"Having done some background research on the region for some project evaluation, I have come across the debate between impact vs. tectonic origins. IIRC, there have been no signs of impact-related geological features (shatter cones, high pressure minerals, etc.) and the best explanation is a terrestrial tectonic bo... | [
"I did some google-fu and found the [ship referenced on this wiki-list](_URL_2_). It pointed to two further sources. [_URL_0_](_URL_0_) which contains some information prior to German service, and the [Miramar Ship Index](_URL_1_) which has further information but requires a subscription. That list and [Wreck Site]... |
Any recommended books on the dawn of civilization? | [
"it may be worth x-posting this to our sister sub /r/AskAnthropology as well"
] | [
"It isn't necessarily from the \"people's\" perspective but Desmond Morton's \"A Short History of Canada\" does give light to lesser known bits of Canadian history. _URL_0_ Full disclosure, I had him as a professor in university and grew fond of his work. He was Tommy Douglas' second hand man in the 60s - so he do... |
This whole 'locked in' referee thing | [
"The NFL is trying to change the referee's retirement benefits from a defined benefits plan (pension) to a 401K (where there are no guaranteed benefits and each individual referee contributes to their own individual retirement account). The referees don't like this. Instead of trying to reach an agreement with the ... | [
"> Why is it a big deal? It qualifies as a \"remote sensing space system\" which requires a license to operate. Presumably they could have obtained such a license but by the time they understood that one would be needed it was too late. > Also, why was this never an issue before? Perhaps they were in violation of... |
[Medieval Sex] How did the idea originate in the Middle Ages that a female orgasm is required for procreation when society *also* believed in ONLY having vaginal sex? | [
"While I've got some knowledge here, I don't have the qualifications to discuss things, so let me offer some other relevant links for discussing hygiene... * [With deodorant first really coming out commercially in 1888 in Philadelphia, did most of the world just smell like armpits once the clock struck noon on a wa... | [
"Imagine a flamethrower and a crowd of X-Men kids. there's a range of powers. Burn the crowd for 20 seconds and they all die. Burn them for 10 seconds, and maybe that thick skinned or overly hydrated kid survives. He wouldn't have survived the assault for 20 seconds, they would all have died. But now he survived. X... |
When a computer game is loading, what’s actually happening? | [
"Suppose i asked you to dial \"9116644\" on your phone. One way is to look here, \"9\", and press the button. Then see \"1\" and press the button. And \"1\" and press the button. Too slow. Other way is to keep the whole number in mind for a while and just press the fingers one by one. So there's two kinds of storag... | [
"IRL car races, you have to earn your spot in the starting grid through qualifying. Since there are no qualifying in video games, you tend to start at the back. Haven't played a racing game in a while (outside of Mario Kart, but even that was a while ago), but IIRC you do move up in the grid based on your performan... |
Is there any other point in history where former slaves became equal to their masters i.e. American slavery of Africans? | [
"You'll probably find examples of this in the early Reconstruction period, but I couldn't provide specific examples as that's not my field of expertise. However, former slaves did at times find themselves in unique situations that allowed them to subvert the standard order. In 1768, the 29th Regiment of Foot was di... | [
"In 1881, at a Royal garden party in London, there was a question of precedence between the Crown Prince of Germany and King Kalakaua of Hawaii. The Prince of Wales (the future Edward VII) insisted that King Kalakaua was superior as he was a King and not merely a Crown Prince, even though a German Crown Prince was ... |
why comic book art seems to get "better" over time | [
"The only change as far as what the artists are capable of is the advent of stuff like photoshop. Artists in the 50s could have drawn tiny details or painted whole pages, but comics were made to be affordable to little kids, so they used cheap printing techniques, so all that effort would have been wasted."
] | [
"Supply and demand. I know this is a simplistic answer, and I'm not trying to be flippant, but that really is the answer."
] |
Scientific Theory vs. layman's idea of theory. | [
"Scientific concept of a theory: \"Based on our testing and observations we believe this is the way things generally work.\" Layman's concept of a theory: \"All that science and you guys only have a *guess*?\""
] | [
"Remember when MTV used to show music videos instead of reality tv? Remember when the SyFy (Nee SciFi) network showed science fiction shows instead of professional wrestling? Remember when TLC (The Learning Channel) showed actual documentary type shows? (Insert obligatory \"Pepperidge Farm remembers meme here.\") T... |
Why is it okay in the U.K for people to have sex at 16 but not watch porn until they're 18? | [
"It's not illegal for people under 18 to watch porn in the UK, because private possession of porn isn't illegal. So a kid at 16 could legally watch all the porn they want. _URL_0_ > The sale or distribution of hardcore pornography through any channel was prohibited until the rules were relaxed in 2002, however the... | [
"It has to do with the contracts the networks sign for the show. Typically shows are contracted by the season - but often they will buy a season with a certain number of episodes with an option to buy more episodes under that contract if the show is successful. For example - They will sign a contract for 1 season o... |
Why can our bodies extremities handle much greater variations in temperature compared to our cores? | [
"The answer is fairly simple: there aren't any important organs at your extremities. The small muscles and tissues at the ends of your limbs aren't necessarily more resilient, they just aren't as important to body function. Your kidneys and liver need to work always, the pinky muscles don't."
] | [
"Look at it like a phone and charger. If you put a load of energy into the phone (more than it's rated for), it'll do serious damage almost immediately. If you use an underrated charger, it'll put only a little energy in, but the phone will use more than it's getting and eventually die. Heat is just a form of ener... |
how does an organ work? | [
"The key depresses a lever, which lifts a flap inside the tube. Pressurized air behind the flap moves up the tube and comes out the holes at the top, vibrating the tube at the frequency for that note. Today, organs are powered by an electric engine that blows the air. Before electricity, bellows were used to keep t... | [
"Radiolab does a really good job of explaining it like I'm 5: _URL_0_"
] |
Why do we say websites are worth Millions of dollars if they don't make a profit? | [
"They are generally projecting future revenues for the company."
] | [
"It depends. In the US and other 1st-world countries, you can use tax records, asset prices (assets are stocks, real estate, etc.), salary data and other freely-available data to come up with a good guess. Other countries might require some more guesswork, but the principle is the same."
] |
Why do referees in soccer games fall for the obviously fake injuries, and penalize the opposing team? Why hasn't anyone changed the rules in the game by now to prevent players from faking an injury to cheat the game? | [
"Actual Soccer/Football ref here: The issue is: refs don't have replay, slowmo, or the best vantage point all the time, so you do you best to sort it out through your experience of reffing games. It is already illegal to take a dive, but many times there is actual contact between players, just played up. In soccer,... | [
"When dogs were first domesticated a long, long time ago they were primarily used for hunting for quite some time. After a few millennia of evolution we bred a lot of hunting based instincts into them, one of those being retrieving prey for their master. Basically, when your dog brings a stick to you it's simulatin... |
What's the cause of that horrible feeling in your chest when you're well and truly heartbroken? | [
"Scientist have shown that strings in the heart can literally break, or tear, due to stress. Your heart can actually be broken. Look it up on Google, it's a legit thing. I'm just too lazy to post the link since I'm about to leave work."
] | [
"The body can get energy from two sources (well 3, but since you are a kid I'll ignore alcohol. Also, I don't think that's stored in the body for any length of time anyway) fat and sugar. When you eat the body immediately starts using all that delicious sugar it got. After a while it starts running out of sugar an... |
Why do train tracks always rest on rocks/pebbles? | [
"The rocks can flex against each other. Solid earth (or when mud fills the spaces between the rocks) won't flex, and the ties work themselves into loose holes. There are [machines](_URL_1_) that stir up and clean the rocks under live tracks to keep them flexible."
] | [
"You want to easily be able to identify where the missing texture is, and a purple/black checkerboard is pretty damn noticeable in 99% of cases. And once one person used it, some more started using it, and it kind of just self-standardised"
] |
How could an MI5 agent or similar verify they worked for the government if they were recruiting a civilian for a task? | [
"agents don't recruit civilians for tasks. agents recruit assets. assets don't work for the agency. they work for the agent. agency recruiting for new agents works just like a _URL_0_ job posting. recruiter goes to a potential hire. \"how would you like to come work for the CIA?\" or even better the potential hi... | [
"> but how does that work? Suppose I am going to launder money and I create a charity. I am going to only hire myself as well as some close family and friends to administer this charity, paying them a generous wage. (Yes, charities pay their employees, they are not always volunteers.) In fact it is so generous that... |
The "V" shape is a popular configuration for 6 and 8 cyl engines, but not for 4cyl engines. How come? | [
"Inline engines are easier and cheaper to produce than V engines. But, larger inline engines such as 6's and 8' are too relatively large, so manufacturers opt for a V engine to save space. An inline 4 can easily fit in most automobile engine compartments, so they opt for the cheaper to produce inline 4 over a more ... | [
"DNA is stored in large clusters inside each cell in your body known as Chromosomes. Each cell has the exact same set of DNA. There are a total of 23 pairs, or 46 total chromosomes for humans. You get 23 of them from your mom on one side of the pair, and 23 from your dad on the other side of the pair. One of these ... |
How come some people can seldom or never brush their teeth and seldom or never develop cavities, while others adamantly brush 2-3 times a day, and develop many cavities? | [
"Cavities have more to do with diet than brushing! I recall one study where a dentist went to a very remote village in Africa or Asia and they didn't have tooth brushes. He cleaned teeth and was amazed that after cleaning teeth that were completely black with built up plaque, there were no cavities or any real issu... | [
"A routine is what the body follows for sleep, hunger, fatigue, etc. If you make it a point to wake up everyday at 6am by an alarm clock, the body adjusts its internal functioning to match that routine. Then even if you take away the alarm clock, the chemical changes in the body, thanks to the routine, will automat... |
Are animals able to distinguish their own siblings if they grew up together, got separated (i.e. zoo or adoption), and if they're reunited in adulthood? | [
"My dog lived for her first 6 months with her sister who she was identical to. They were very fond of each other. We had other dogs and plenty of mirrors but when we adopted her she would sometimes catch sight of herself in the mirror and immediately drop her ears and start wagging her tail the way she does when sh... | [
"Genetics and Immune system explanation time. Basically, the way your immune system works is that certain proteins are present on your defense cells that will attach to certain other proteins, called antigens, on other cells. It's how they attach to bacteria. Due to complicated genetics, your body and organ cells h... |
How did the United Kingdom go from being one of the United States's most hated enemies to being one of its most trustworthy allies? | [
"Follow up question: is it accurate to describe the UK as the 'one of the most hated enemies' of the new United States? Was there really that much animosity between the two states? After all, a significant minority of US citizens were Loyalists and the countries shared a significant amount of commonalities, languag... | [
"In addition to what others have said, sometimes new information can change things. For instance, a candidate might make a campaign promise to never interrogate people. When he gets into office, he finds out that 10 terrorist attacks in the last year were stopped because of information found while interrogating ter... |
How can I protect my computer data from an Electro-Magnetic Pulse (EMP) event | [
"To protect data on electronic or magnetic media from an EMP, you would want to wrap the media in an insulative material (preferably anti-static, like an anti-static bag you can get at a computer reseller / repair place) and then put that inside a **grounded** faraday cage, which can be made by welding or wiring to... | [
"Those websites aren't interested in what happens when SHTF. They are interested in what might happen this week, namely that people might send them money. They are definitely in favor of people sending them money. If sending you gold, or MREs, will get you to send them money, then they are all over that. Since the ... |
How would the pyramids have appeared to Alexander the Great when he invaded Egypt in 332 BCE? | [
"Much nicer. The pyramids at Giza were once covered by fine white stone. The remnants of such stone can still be found at the top of the pyramids. Over the millenia, these stones were stolen or destroyed. [This page goes into detail about the beautiful outer stones.](_URL_0_)"
] | [
"This has essentially been answered by the preceding comments, but what hasn't been contributed is this: _URL_0_. Muster and enrollment records, transfer lists, honours lists, etc, for the period of 1730 through 1898. Worth having, OP, if you're writing or researching the topic academically. To succinctly summarise... |
How is it "too hot" to fly airplanes? | [
"It's not too hot to fly any airplanes, it's too hot to fly certain airplanes. Heat means lower air pressure, which means a given wing generates less lift, at a given speed. When the given speed is more than the airplane can generate in the space of a runway, it's not leaving the ground. Military planes are desig... | [
"They can be, if not kept dry. Humans are always affected because they have moisture in their skin (perspiration) that evaporates and causes cooling."
] |
Why do you require excess calories to gain muscle yet when not working out the excess calories make you fatter? | [
"When you work out you actually tear your muscles. Once you are resting your body repairs them, and this is how you actually gain muscle mass. So naturally it needs nutrients and food to break down and convert into that new tissue. However when you just overeat without working out your body doesn't have any repair... | [
"Using my uni physics class, we actually calculated this... when there is more in the fridge, there is less space to keep cool. It therefore takes less energy to run a full fridge than it does an empty one. This is assuming that the food is already cold or room temperature when you put it in the fridge. Hot food w... |
Why do television camera crews use very large cameras to film, but my go pro cam shoots HD and is smaller than my fist? | [
"I'm not a camera pro, but basically: A smartphone camera lense or even a Go pro doest have 1/10th of a cinema camera quality. There is much more than resolution and megapixels when it comes to cameras. Why does some 8mp phone camera does a better job than some 13mp ones? Same stuff. Lense, picture processing, etc.... | [
"The sets and props weren't expensive. Foam, plaster, and plywood are cheap. The artisans to build them were expensive. Good people with marketable skills are expensive. That hasn't changed. Now instead of hiring a bunch of set guys and prop guys and costume guys you're hiring a hoard of CGI guys and renting hundre... |
How in the film/musical 'The Producers', having a flop would make more money than a hit. | [
"They raise money for the play by selling shares in the future-profits, so that people who invest in the making of the play expect to get a pay off at the end. However, they sell many more shares and raise a lot more money than they actually think they'll need, on the basis that when the play flops the investors wi... | [
"Many of the products sold through infomercials, especially information products, are not actually created until an order is placed. So, you may order a DVD set today but the next batch of orders are not created until the next week. It's a sort of 'standard' that the price of shipping should cover the entire cost o... |
How will Voyager 1 keep its antenna pointed at Earth once it crosses the heliopause? | [
"[Voyager 1](_URL_0_) is at about 122 AU from Earth. Earth's entire orbit [subtends an angle](_URL_1_) of less than 1 degree, about twice the angle subtended by the moon viewed from Earth. It has a [3 axis thruster system](_URL_2_), and has only used about half of the fuel it started with."
] | [
"They only go home. They're one-way message carriers. You take one from where it's living and bring it elsewhere, then tie a message to it and free it, and it'll go back home. They can't be used to send a message to some arbitrary location."
] |
What is the process for removing a tattoo? | [
"A tattoo is permanent because the ink particles are large enough that your immune system cannot remove them easily. Tattoo removal works by hitting the tattoo with high intensity laser light, making the ink particles break apart into smaller clumps, allowing your body to remove them. The laser also damages the ti... | [
"Pretty sure they’re optical sensors that use a bright light to illuminate your veins and then take a sort of “picture” of how rapidly the veins are shrinking and expanding."
] |
Cyclic redundancy check | [
"When transmitting data, a CRC can be used to quickly check if the data has been corrupted. The data bits are used in an algorithm which forms a CRC value. This value isn't unique, but minor changes to the data will generate a different CRC, telling you the data was corrupted somewhere."
] | [
"1 for backup. 3 would cause too much risk of them tangling up or crushing each other. (one is already slightly higher than the other to reduce this risk)"
] |
Pre "On the Origin of Species", were there atheists, or did all scientists believe in creation? | [
"There have always been a large nubmer of belief systems other than Abrahamic creationism, and there continue to be also. From a purely scientific standpoint prior to proof of evolution there was no accepted idea of how we came to be, it was an open question. Today there are still many things science is simply sile... | [
"Indeed we do, albeit the ones we do have come along towards the end of the Golden Age of Piracy. In fact, the fictional story of Robinson Crusoe is thought to be based off of the real story if Scottish buccaneer and self-inflicted castaway [Alexander Selkirk](_URL_0_). He was rescued, much like his fictional count... |
In baseball are there different batting strokes, as there are in cricket? | [
"Only thing I can think of would be opposite (hitting to the opposite side of your position) and bunt. I guess you could consider line drives, fly balls, and pop ups different hits if you wanted to. Mostly it is hitting the ball into the spot that will most likely get you on base or more importantly score a runner ... | [
"Actually we do. _URL_0_ The reason its so complicated is because we have so many dialects, accents, and speaking mannerisms. The program itself needs (I believe) a minute of speech from the subject before mimicing the speech."
] |
if heat rises why is outer space cold? | [
"Heat rises because warm air is less dense than cool air. There’s no air in space, so no heat can rise"
] | [
"When you blow to cool things down part of the air comes from your lungs, but a greater part is pulled from the surrounding air by the vacuum you create blowing. When you blow to heat something up you get much closer and try to minimize the surrounding air. There is a good video I will try to find asking people how... |
Do we know if any romans ever commented about modern day italy looking like a boot? | [
"Kind of a side question, but did Romans even know what boots were? I can assume they had basic sandals, shoes, and maybe a form of boots, but would they really have any knowlage of what a modern boot would look like?"
] | [
"The name calling is used to silence and nullify their arguments. In WW2 France made a lot of poor decisions when it came to defense. The Germans broke through and stormed Paris, which was given up without a fight. The reality of the situation is more complex, but the obviously childish sentiment is fun to join in ... |
Why do alot of people hate The Conservative Party of Canada? | [
"-he has neglected to attend several environmental conferences -he is pushing against the gun registry -he is cutting funding for various art and culture programs -he has royalist tendancies Etc. Basically, he's a conservative. The internet seems mostly to be populated by liberals. Thus, the canadian internet popul... | [
"\"Just about everyone here\" Where is \"here\" for you? It sounds like your question's premise is based on a small sample set based on personal observation. Before your question is addressed, you should be making sure the premise is valid..."
] |
What are the long term effects of massive antihistamine usage? | [
"You might get an answer to this question, but imho the question is borderline asking for medical advice. Asking for medical advice is frowned upon here and giving medical advice is against the guidelines for this sub."
] | [
"There are a couple things going on here. First, there are lots and lots and lots and lots of ants. There are probably more ant _colonies_ of a typical ant species per square mile than there are individuals of a typical mammal species. I mean think about it. How many anthills are in your back yard? Now, how many de... |
Recently, I've been seeing a lot about the stance that "American politicians aren't representing people; they're representing corporations." Can someone please fully explain this stance? | [
"American political campaigns are funded by donations. The rules of the campaign state how much money a given organization, corporation, or individual can donate. Political campaigns are expensive and regularly getting more expensive. Between non-profit organizations, individuals, and corporations, the only group w... | [
"Parliamentary systems elect specific parties, who then negotiate into coalitions to govern. In the US system, we vote for what are effectively two coalitions so the long season is where the negotiations take place (and then voters choose the coalition they prefer). Because the coalitions can sometimes change prett... |
Do high price exotic "trophy hunts" actually aid in wildlife preservation? | [
"In theory, the hunter pays a lot of money to the park. Park then allows him to hunt down older animal or animal that is a danger to people. Money is then used to run or improve the park. In reality there is risk for corruption of the park rangers (these exotic animals live in areas notoriously known for corruption... | [
"There are a lot of people in the world who don't care about laws, or the laws of other countries, or the property rights of other people. For example if you stole a piece of art from someone in England that a wealthy member of the royal family in Saudi Arabia wanted they probably don't care at all that it was stol... |
The human body produces enough heat to bring half a gallon of water to boil in 30min, what do our bodies do to produce so much heat, especially when idle? | [
"Every expenditure of energy produces heat. And the body is constantly using energy. Your heart beats, blood is pumped around the body, you breathe, the oxygen is mixed into your bloodstream, nerves are sending electric signals to your brain, your brain is doing everything *it* does, your immune system is fighting ... | [
"Depends on if you're asking about infrared heaters or convection heaters. An infrared heater heats by emitting infrared light that interacts with most matter by heating it up (you feel it as warm). It's efficient if pointed at a person/object because it conducts most of the energy on target. Convection heating wor... |
Why does my fuel economy suffer in the winter? | [
"Well, it's true there are different additives that make up different types of fuel, Summer/Winter. This should only lead to a marginal decrease in efficiency/power. However, the change you are seeing is fairly significant. This is most likely due to 1) your tires being under inflated, which increases the rolling r... | [
"\"The major loopholes in the current EU tests allow car manufacturers a number of ‘cheats’ to improve results. Car manufacturers can: > * Disconnect the alternator, thus no energy is used to recharge the battery; > * Use special lubricants that are not used in production cars, in order to reduce friction; > * ... |
Brand name products VS Generic. If both are the same, why are there both versions? | [
"In the pharmaceutical industry, it has to do with patents. When a big research and development company puts millions or billions of dollars into producing a new medication they get the right to distribute it exclusively for a period of years in order to recoup the cost. After several years (7 I believe?), generic ... | [
"Online tracking is easy. Whenever you click on an ad, it sets a cookie on your computer that marks you as arriving to that site from the ad. Your each activity on that site is tracked and noted when you make your purchase. Offline is a bit different. Depending on the size and marketing efforts of a company, they m... |
The relevant differences between totalitarian and an authoritarian regimes. | [
"Authoritarian regimes want to consolidate and centralize power so that governments have all of it. They avoid checks and balances or anything to maintain the government's control. Totalitarianism goes further than that. In an totalitarian regime, checks and balances don't even exist. The state is all that really ... | [
"Hi there, those interested in recommending things to OP! While you might have a title to share, this is still a thread on AskHistorians, and we still want the replies here to be to an /r/AskHistorians standard - presumably OP would have asked at /r/history or /r/askreddit if they wanted non-specialist opinion. So ... |
Why do people sometimes have momentary confusion on how to do simple everyday tasks? | [
"Think of your brain like a billion streams of water that flow over the surface of a rock. The more you use a certain stream, the more \"powerful\" that stream becomes by digging away that rock. Now even if you have a nice dug place for a stream, sometimes randomly that stream won't have needed to flow for a while ... | [
"This sounds like an extreme example of \"Tip of my Tongue\". _URL_0_ I can't really give an overly scientific answer as to what causes it (some interesting articles on that page, though), but I'd imagine that it's just a \"brain fart\", kinda like deja vu. It's a problem with long-term semantic memory recall. (Se... |
Why does very cold stuff burn the skin? | [
"A burn is tissue damage usually in the form of the membranes in cells breaking apart whilst the substance remains intact. Cold causes the water molecules in the cells to align into ice which expands and ruptures the cell walls. In the case of nerve cells this increases conductivity and electrical signals short cir... | [
"It is how we are evolved. Humans are first evolved as [endurance runners](_URL_0_), being able track games through persistence hunting mid-day. We were able to do so by sacrificing our body fur - which regulates body temperature and allows us better cold endurance - for our hairless bodies that could fair better i... |
Millenium Development Goals | [
"The Millennium Development Goals were a set a goals that the UN set in 2000 to try to improve the position of the worst-off people in the world. Each goal had specific, measurable targets associated with it so that they could evaluate whether or not they were making progress on the goals. For example, goal 5 was \... | [
"> Why isn’t the U.S. successful at rebuilding areas in the Middle East and North Africa? Because that was never the goal."
] |
Theory of relativity? | [
"This is a frequently asked question here... you should search some of the previous answers."
] | [
"basically you gain extra speed without using valuable fuel. simple example train is coming towards you at 80km/h. you throw a ball at train with 10km/h. from train point of view ball approaches it at 90km/h, then it bounced back at 90km/h, from your point of view ball bounces back at 170 km/h."
] |
In the show Vikings, it implies that the Roman Empire is essentially forgotten by c.800 CE. how accurate is this? | [
"You might be interested in my answer [here](_URL_0_), which argued that educated individuals were very aware and in awe of the Roman empire, especially because at that point the empire still existed! I only covered events up to 700, but I don't see any reason why this would change over the next century. I mean, th... | [
"You're going to need to narrow down your time frame here, keep in mind you're asking about a time frame of 1000 years over a very, very large area of land with vastly different cultures. You'll be more likely to receive an answer if you narrow the question down to a more specific time."
] |
How do Stealth Bombers work? | [
"Radar systems work by beaming radio waves at something and paying attention to what bounces back off whatever is in the way. Stealth technology basically either uses materials that absorb those waves so that not much reflects back to the receiver (making it appear smaller than it really is, or not there at all), o... | [
"It follows the same principle as my dog working his way between me and my wife sleeping in bed."
] |
What is the observer effect? Does light really know when we are observing it and change behaviour depending on it? | [
"In physics, an \"observer\" is anything that interacts with a quantum object. For instance, when a photon hits your desk, the desk \"observes\" the photon. So the observer effect just has to do with whether anything is interacting with the photon."
] | [
"\"You're sitting in a chair\" and \"I know you're sitting in a chair\" don't mean the same thing, of course. The former is entirely a statement about you; the latter includes that statement, but also makes a statement about *me*. Now let's introduce Jane. Jane is staring at you from a hidden camera because she's a... |
how do companies such as beezid actually work? It sounds way to good to be true | [
"You pay money to buy a stash of \"bids\" at a cost of roughly $0.60 per bid. Each time you \"spend\" a bid, you raise the price of the item by $0.01, become the current winner, *and lose that bid forever*. Every single bid costs you a non-refundable sixty cents, and if someone outbids you (and they will), then you... | [
"They calculate with what a average person would eat (because jot everyone eats tons just because it's all you can eat) and choose a price after that calculation. There are also person who don't eat much (old people e.g.)."
] |
Why do services like Facebook and Google Plus HATE chronological feeds? FB constantly switches my feed away from chronological to what it "deems" best, and G+ doesn't appear to even offer a chronological feed option. They think I don't want to see what's new? | [
"Facebook does so because they charge people (mostly companies, but you can pay as a person also) to get their posts at the top of your feed. Actually, if you are a company, Facebook builds their site so that your views will drop over time unless you pay them."
] | [
"The rear wheel stores the same amount of energy per unit mass as does rest of the bike and rider. The rear wheel has something like 5%-10% of the mass of the system. Therefore it stores something like 5%-10% of the energy of the system, not enough to smooth your ride in any significant way. *but* a fixie will forc... |
If a computer hash is procedurally generated, and will always result in the same output given the same input, why is it considered irreversible? | [
"An apple is red. A fire truck is red. The thing I'm thinking of is red. Was it an apple or a fire truck? Or was it a fire hydrant or a rose?"
] | [
"It's like in Mario Kart where if you drive off the side into the mud, the drag slows you down. If you drive back to the road in a perpendicular fashion, you minimize your time in the mud, but you've built up no momentum once you get to the road. If you drive parallel and angle yourself gradually toward the road, y... |
Why is it that things (for example, commercials or movies) go by faster the second time we see them? | [
"Because our minds are not processing new material. Our brains are good at pattern recognition so when we see something we remember, our brains don't have to work as hard to take it in. I theorize that this is one of the reasons most sequel movies aren't as good as the original. In the first movie part of the exci... | [
"Simply put for the same reason drinking water when you're not thirsty isn't as refreshing as when you're REALLY thirsty. Anticipating the bodies' needs doesn't trigger the same reward responses in the brain as fulfilling a need that is already present. Your muscles don't NEED to stretch right now, so you can't ant... |
Are all programs eventually translated into machine code? | [
"Yes. Machine code is the series of instructions that guide the underlying hardware to perform the actions you want it to take. It's the \"language that the CPU speaks\", so to speak. Machine code is the only thing that the CPU can run, so everything has to ultimately be converted to machine code."
] | [
"Right now it the closest we have gotten is using artificial neural networks. _URL_0_ It isn't quite as complex as mapping all of the synapses in the human brain. Basically we can make a neural network, and by feeding it a set of inputs and the correct output, we can teach it what kind of output we want in the futu... |
When I look at a picture of greater resolution than the screen im using, what happens to all the extra pixel data? | [
"It depends on what program you're using to view it. The simplest algorithm to display that would be showing 1 of each N pixels, so the answer to \"why\" is that they're chosen simply arbitrarily in that case. If a program is using this algorithm then you can realize because very thin lines just disappear when zoom... | [
"It becomes fat. Calories are energy, and the human body really likes storing the stuff, because historically we haven’t had a lot of times where food was in such abundance. Edit: I’m sure there are other things too, such as increasing risks for heart disease and the like, but this is Eli5, not a medical journal."
... |
If all the other Candidates (of any specific party) have suspended their campaigns, does the one remaining candidate win by default? | [
"Not automatically -- those candidates will still be on the ballot, so they can still collect votes, it's just very unlikely that those votes would change outcome at this point. Trump and Clinton are not officially the nominees, but at this point it's pretty safe to assume that they will be. That's why news media h... | [
"Depends on the material and temperature. Sometimes the surface forms a reconstruction, as dreykevins explains. Other times the surface forms an oxide or some other surface layer, which can prevent recombination. Other times the pieces actually CAN be put back together, and this process is called \"cold welding\". ... |
Why do comments with ~3000 net karma have a ton of upvotes, but also a ton of downvotes? | [
"Because reddit fiddles with the displayed total of up/downvotes to prevent bots from scamming the system. You can basically trust the TOTAL amount of karma, but not the total number of up and down votes, since that is not accurate. Basically, if bot creators were able to see the precise impact of each vote, then ... | [
"If you ask for 1 pen, it costs you two dollars. If you ask for 100 000 pens, they will only cost you one dollar each. I prefer selling you 100 000 pens at half price, than selling you 1 at full price and have 99 999 sitting around doing nothing. In a similar way, if you ask for a small amount of money, you pay a b... |
How do sound waves explain the sounds for particular words, distinct voices, and timbre of instruments. | [
"The characteristic sound of something is determined by its waveform (the actual shape of the wave that you hear). Any wave can be made by adding together different amounts of waves of different frequencies. If you know much about math, this is called a Fourier series. This means that most sounds you hear in your d... | [
"This is a very large topic area, so I'll just touch a piece of it and leave you with a more thorough source. In the case of birds, it has generally been found that birds raised in total isolation from their own species will eventually start singing regardless, and that song will resemble the songs sung by other in... |
Today is Memorial Day in the United States. Can someone explai the history of Decoration Day, the post-Civil War precursor to Memorial Day? | [
"you've me interested now. I found this blog talking about it, it also talks about the interesting ceremony with their Confederate and U.S. flags _URL_1_ a quick google search also gave me this cite for the Center for Civil War Research: _URL_0_"
] | [
"If, after the individual pays what they can and any assets are seized, there is not enough money to cover the remaining debt, then wages are typically garnished until the debt is closed. However, this scenario happens a lot more than you would think. Hence why sometimes you'll hear tossed around the phrase \"Judgm... |
How does our brain know if a sound is coming from straight ahead or straight behind us since there is no timing difference between left and right ear. | [
"Because of the shape of our ears. Sounds from behind us have to go through the fleshy outside ear. Sounds in front of us don't. That makes them distinguishable so we can tell if it's in front or behind us"
] | [
"Simpler explanation: I write you a letter that says \"This letter was sent from < my address > on < date > and < time > . Please send me a letter back as soon as you get this, with the exact time and date you received this. You follow the instruction and send the second letter back to me. When I get your letter, I... |
Why can't fast food be healthy? | [
"1. It's expensive to produce high quality food. You have to start with high quality ingredients and process it/cook it properly to retain the nutrition. This doesn't scale well to mass-produced foods, and people want fast food to be cheap. 2. Fast food sells really well because it panders to our inherent desires f... | [
"Please everyone, \"Super Size Me\" and other such documentaries are not considered valid scientific sources. Please refrain from referring to them as such."
] |
Why does the definition of "cool" change? Why do fads exist? | [
"It changes because the \"cool\" thing is no longer a novel concept. People often want to have the newest technology/fashion/etc, and so when seemingly *everyone* has the same thing, it stops being cool. Trends come back for the same reason - for example, neon was pretty popular in the 90s, then everyone wore it,... | [
"Inflation. Let's put it this way, in America it used to be that you could buy a steak dinner for let's say $5. Then today that same steak dinner would cost $50. How much we pay for things, and how much we get paid has increased slowly over time. In other countries, it has increased way faster, so something that us... |
Why do many white collar professions have ridiculously long hours? | [
"Many jobs don't have school like tasks. Complete this 10 page report. That takes a few days of work. Those financial jobs you're talking about have goals that are measured after month, even years. Daily goals are hard to finish when your goals is literally \"Make this much money for my company this month\"."
] | [
"It takes a while to implement the changes. How would you like it if the law changed overnight and you had to pay fees/go to jail next day without having a chance to adapt yet."
] |
Friday Free-for-All | Oct. 5, 2012 | [
"Here's a fascinating [German article](_URL_0_) about Erwin Jöris, who was imprisoned by Nazis, Soviet Union and the GDR for his political activities. Depressing as shit. Reminds me of the also fascinating \"Die Revolution entlässt ihre Kinder\" by Leonhard. People tend to forget that Stalin killed more German com... | [
"I don't have the time to answer this in depth, but *1913: The Year Before the Great War* by *Charles Emerson* seems to be exactly what you're looking for. Be careful not to adopt a teleological view of history - even though it's obvious to us that WWI 'will happen', people at the time weren't quite so convinced. T... |
How does catnip work, and does it have negative side-effects on cats? | [
"Catnip is hard for us to understand because there is nothing quite comparable (except maybe the scent of food causing us to salivate - simply an automatic reaction to a certain smell). Catnip does this to a cat: The smell triggers the rubbing, purring, or rolling. Specifically, a chemical called nepetalactone caus... | [
"Plant cells have little starchy organelles called *statoliths* - they're much heavier than other components of the cells. The statoliths fall to the bottom of the cells. In cells in the stem, statoliths on the bottom of the cell trigger the hormone auxin to inhibit growth on the lower part of the cell. This makes ... |
If black holes suck in all light and therefore are pitch black, how did we 'find' them? | [
"It's called Gravitational Lensing. Basically the gravity is so intense it causes the light from other objects to distort. We have also detected radio waves/exotic radiation from the matter being obliterated."
] | [
"Through exposure. Put a camera in a dark room and take a long exposure picture. They do the same thing for seeing things far away in space. The reason it takes satellites so long to get a picture is because they have been taking a long exposure shot the entire time."
] |
Why are there off brand Lego type products being sold now? | [
"In the USA, a patent has a proprietary time frame. (maybe the correct term) I believe it is 17 years. Once that time frame is up, they can't use your logo or brand name, but they can use the general aspects of your patent."
] | [
"Nothing is stopping them. [ReactOS](_URL_0_) is a binary-compatible windows clone, for example. As for Apple's OS X, it itself is a clone/fork of [FreeBSD](_URL_1_)."
] |
People of Reddit that work in an I.T department, what can you actually see? | [
"Used to work as an IT admin for a reasonably large company. Yes I had access to mail stores, network shares and just about every non-encrypted file on the domain. No, never had a good reason to look at anything I shouldn't. Any IT department worth their salt has audit logging for that kind of thing. Basically if ... | [
"This is called the [Moire Effect](_URL_0_). The stripes in the pattern interact with the stripes in your monitor. Normally it's in black and white, but because computer monitors use rows of colored dots, it creates a false color effect too."
] |
Why is the air in the atmosphere of earth not get sucked into the vacuum of space? | [
"Yes, it's gravity mostly. Gravity pulls most molecules of the atmosphere back to Earth before they can escape. hydrogen and helium, though, do escape Earth's gravity because they rise to the very top of the atmosphere and have a velocity larger then Earth's escape velocity. Larger molecules of Earth's atmosphere d... | [
"Particals spread out over time (thats why if I sprayed something in one corner, not everyone would smell it at the same time) so over a longer period, the particals move further and further away from the point of origin, and the particals spread thinner and thinner, to the point that you dont notice it anymore."
] |
Why were the Dutch so successful in the early colonial period, and why didn't their power last? | [
"Something that should be higher on the page: the Dutch were not an early colonial power. They became a global presence well after the Spanish and Portuguese, and the Dutch maintained a significant world presence well into the 20th century, especially in the populous (and profitable!) East Indies. So it's completel... | [
"It was a \"pump and dump\" scheme. Buy up a company that is doing terribly, talk it up like it is doing wonderfully along with faking your income reports, then sell off some shares while everyone thinks it is hot stuff. Then vanish with your gains before people discover it was all smoke and mirrors."
] |
Electric and magnetic fields as Em light? | [
"You can, in a rough way, treat static electric or magnetic fields as \"light of infinite wavelength (or zero frequency).\" Sometimes, such an approximation is used to solve some problem or other."
] | [
"Look at [this picture](_URL_0_). Pretty much gets the idea across. The lines in the picture represent magentic field lines. Note how the disk is sorta \"pinched\" between them. In that fashion the disk is held in place."
] |
what the arrows mean in illustrations of the magnetic field for magnets | [
"They are to illustrate magnetic field lines showing the direction of the magnetic field at that point. If you were to take a simple bar magnet and in it to a spot center on one of those arrive so that it could freely spin, but not good around, then it would soon until it lines up along the arrow. The arrows show y... | [
"It is called \"Vigrid\" in modern Norwegian; [Wiki](_URL_0_) has an article on it. I always thought the etymology was 'vi', modern 've', English 'woe', and 'grid' meaning mercy, so \"No-Mercy Field\"; but apparently not."
] |
Why is Africa still so poor and underdeveloped after decades of western world help? | [
"Many African countries have and continue to have astonishingly high growth rates, but it's important to remember just how poor a lot of these countries were at independence. the Democratic Republic of Congo had a population of about 15 million at independence. Among those 15 million, 16 were college graduates."
] | [
"From the exact same XKCD article that you linked: > (Climates can be hard to predict—for example, in our world, Somalia and French Guiana both sit on the equator, at the eastern coast of a continent, and seem like they should both receive a tropical sea breeze. But coastal French Guiana is dense rain forest while... |
I am a 5'4" tall woman, which is the average height of a woman in the modern US. Was there ever a time/place in European history when I would have been considered tall (or edging towards tallness) for a woman? | [
"You would have been slightly above average for parts of the 17th 18th and 19th centuries as well part of the 20th( in Europe). However in the Middle Ages people actually weren't much shorter than they are today ( Men at least). However that all depended on social class, location, and a variety of other factors So... | [
"Here is a thread you might be interested in: [How did people cut their nails before the nail clipper was invented?](_URL_0_) Fashion in inscrutable, but there are indications that the Romans, at least, liked neatly trimmed nails. If you look at this [sculpture of Constantine's hand](_URL_1_) , you can see that the... |
Why does 50% haemoglobin saturation from carbon monoxide poisoning kill humans, but a 50% Hb reduction from say, anaemia doesn't? | [
"It has to do with the binding affinities that CO and O2 have for the Heme portion of the red blood cell and the cooperative binding of molecules to hemoglobin. There are multiple places where oxygen or CO can bind and it's easier to bind more of these as more of these spaces are filled, in a sort of positive feedb... | [
"Premature death simply means someone died before the life expectancy for that population. In the case of the German population, presumably you'd use their[ population table](_URL_0_) (Alternatively, one could use the WHO life table, I assume they break it down by country). So, for men that would be dying before 75... |
How does the moon cause tides? | [
"First things first it's not the moon pulling on the oceans, it's more like squeezing them towards equator, like you'd squeeze a spot. If the water was just being pulled up by the moon you'd see a tide in your glass of orange juice. The subject is quite complex but I really highly recommend you watch this video wh... | [
"[Standing waves](_URL_0_) If you shake a string at right frequency \"knot\" points will form that stay stationary. This is due to the wave created by the shaking and the wave reflected from the other end interfering with each other. Video: Standing waves on a string _URL_2_ Objects that are more complex than a st... |
Why can nothing travel faster than the speed of light? | [
"You're trying to apply Newtonian speeds to relativistic velocities. That doesn't work. The answer is that time and space aren't constant. If you go faster, time slows down, and distance contracts. So, in your case, Person B sees both objects moving away from him at 0.51c. But Person A would see Person C move away ... | [
"Lengths can only contract, they can never be made *longer* than the proper length, in special relativity."
] |
If "The Hobbit" was critiqued for having more frames per second than usual and looking like a television show, why TV shows don't lower they FPS to look more "professional" like movies? | [
"Some do. 30 Rock does this. You can see the difference easily if you compare the two live episodes they did - filmed in higher \"TV\" fps - with a normal episode. They even make a joke about the difference at the end of one of the live episodes (\"Something feels different\", or something like that). Breaking Bad,... | [
"They could choose to match the abilities of the computer that I use to game at 4k and 60fps on ultra, but they don't for the same reason. They need to keep their cost down to keep their profits up. They only need to make it powerful enough to get people to buy it. Any more powerful is a waste. This is a compromise... |
If banks simply pay me a small cut of the money they make with a mix of risky and "safe" investments, why should I put my money in a bank rather than investing it myself? | [
"The FDIC. If your attempts at investment go sour, you would lose all of your money. If a bank messes up, your money is insured by the Federal Government up to $250,000, so you lose nothing. There is zero risk with putting your money in a bank, but investing is always risky."
] | [
"Traditionally, it was very very difficult for an author to publish their book and get it sold in stores. The logistics involved in getting a printer, getting stores to buy that book, having that book shipped to stores, having the book advertised, were so complicated that it just made sense for authors to get throu... |
Why do older models of cars have long antennas, while newer models have short ones or none at all? | [
"The old long antennas were simple quarter wavelength monopole antennas. The science behind them is very simple, for the most part how they work could be done with pen and paper. Newer devices use much more complicated antennas that require lots of modeling and simulation to design, something not possible years ago... | [
"I'm familiar with this behaviour in blackbirds in the UK. It sounds as though the birds you describe are doing the same thing. You have correctly identified that not all birds do this - different species have typical responses to threats and flying fast and low is one such response. Unfortunately for the bird it i... |
Anyone out there knowledgeable in geological matters? | [
"Did this used to be a sphere that you broke open? It seems like you have something similar to a [Moqui marble](_URL_0_). These are basically just iron rich waters that flow throughout the rock and end up precipitating in certain areas that contain a nucleus of a certain material. If it is cylindrical, then you pr... | [
"A village well's. There is enough water deep undeground, just not at the surface. And most beduins today have satelite dishes and internet, So i think they are managing just fine :D"
] |
Has a bomb ever failed to detonate during a test of nuclear weaponry? | [
"In general this sort of situation would be very unusual. If the firing signal did not do anything in the firing unit (which activates the conventional explosives in the bomb), then I don't think there's any chance of it just hanging around being any more or less dangerous than it was before the test. You'd power e... | [
"Are we talking about a coup on city, state, or federal level? Now on a city level we've had a successful coup before. Which is the Wilmington (North Carolina) Insurrection of 1898, where white supremacist Democrats illegally overthrew the newly elected city government, forcing the mayor and the bi-racial council t... |
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