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Why does water have no smell? | [
"Smell (aside from taste) is the best sense for determining the toxicity of something. Because water does not have any toxicity or nutrients, and it is everywhere, humans did not need to evolve the ability to smell water, and so we didn't.\n\nEdit: the nose is just a chemical detector. There are certain chemicals that a human needs to detect for survival, such as the chemicals in rotting flesh etc. Humanity evolved to detect those chemicals, and had no need to detect harmless things like water.",
"Water is everywhere. Even very dry air has water vapor in it. The air inside your lungs and nasal passages has a large amount of water vapor from your body. If it did trigger any sort of smell receptor at all, you'd be so used to it that it would simply be background. Just like you can't really taste your own spit most of the time because you're constantly exposed to the taste.",
"Alright all of these guys replying aren't really giving you the whole picture. Expanding upon /u/kksgandhi, yes, smell is a large indicator of toxicity. This is the reason there are some types of water you can actually smell i.e. river water and ocean water. But, in regard to kksgandhi stating that we never evolved to be able to smell, we can actually \"smell\" water. As stated by /u/bigscience87, water is everywhere, even in \"dry\" air, as a result, we disregard the smell almost entirely. /u/joshpoppedyou does present a good argument that there are animals that can smell water, but it is widely accepted that animals generally pay better attention to their senses and/or have better senses than humans.",
"water does smell, we just can't smell it, various animals have the ability to smell it, this is why they have the ability to seek water in dry areas"
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Suppose I'm a vampire. How much blood should I drink until I kill a person? | [
"I think you'd need to drain more than 40% of the person's blood (2.4L). Still, as a vampire, if you bit into a major artery, there's a good chance it will continue bleeding even after you're done unless you get immediate medical attention. So you could probably kill someone by draining much less, if you just left them.\nThey'd probably feel pain as you start drinking their blood, and then dizziness, followed by loss of consciousness.",
"How the victim would feel is a tough one, since no one has ever been bitten by one before. It would depend on the kind of vampire mythology you subscribe to and the powers they have."
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How do completely different strands of species all share similar qualities? (Ex: Mammals and Amphibians both developing Eyes in a similar fashion) | [
"There are two factors at work here:\n\nOne is **common ancestry**. All living things share a fairly small set of common ancestors. Living things that are more closely related to one another share a more recent common ancestor than things that are less closely related to one another. For example, chimpanzees and gorillas share a more recent common ancestor with each other than either does with (for example) beetles.\n\nIn some cases, common body parts or functions are inherited from common ancestors. This is likely what we see in the opposable thumbs of chimpanzees and gorillas (for instance).\n\nIt's also possible to have **convergent evolution**. In the case of convergent evolution, the same features arises independently in separate lineages. This can happen by chance, and/or because a certain adaptation is very favorable. For example, flight in dragonflies and bats arose independently. We know this is the case because the structures responsible for flight are different in each, and the genes responsible for encoding those structures are considerable different in each."
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how crispers work | [
"If you put a head of lettuce in the fridge, it gains moisture and gets soggy. The additional moisture allows moss to grow as well, making it go very bad. \n\nIf you put it in the crisper, the moisture level remains the same and it stays crispy and fresh."
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What exactly do people mean when they say a game runs on an engine? | [
"> Is an engine just the basis of a game's physics?\n\nThat's pretty close, but there is more to it than that. \n\nThe engine is what takes the *data*...physical description of the buildings, the vehicles, the people, the weapons, the lights and the shadows and the reflections...basically everything in the universe, and draws it on your screen 30 time a second.\n\nEngines take a lot of effort to make. But once they have been created, guns and lasers and magic spells, they all pretty much do the same thing...there is no reason for everyone reinvent the wheel once the make a new game. It is cheaper easier just to buy an engine from someone else."
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Why does heating the house to 70 degrees feel so different from cooling the house to 70 degrees? | [
"Because it's impossible to maintain the room's temperature at exactly 70°F (for a system that switches on and off periodically). In reality, when heating you heat the room to around 73°F, and when cooling you cool the room to 67°F. When the temperature cools or heats past a certain point the system turns on again.\n\nAlso, thermostats are crap, even good ones need recalibrating every 12 months or so. They're almost always off by 2°F or so so house to house won't achieve the same feeling for the same set point."
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If China is a communist state, why are there so many multi billion dollar companies and free markets? | [
"Modern China was founded with communist principles in mind. But after Deng Xiaoping took power, he decided to move China toward a more capitalistic economy. But the Communist Party still rules China and therefore they still are labelled \"communist\". Similarly, the US isn't completely capitalistic because there are government regulations and also government-owned businesses (such as the post office).\n\nIt's really a label more than anything else.\n\nEDIT: Another thing to point out is that a lot of those \"billion dollar companies\" are actually owned/operated by the Chinese government. For example: Industrial and Commercial Bank of China. They have branches in the US now too.",
"Westerner living in China/studied modern Chinese history here. \n\nWhen the Communist Party came to power in 1949, they did implement Communist policies like land redistribution, communal living, \"Iron Rice Bowl\" jobs (guaranteed job security), and such (and they became very popular in the 20s and 30s in rural areas because they espoused ideas like class struggle, the supremacy of the working proletariat, and equality between men and women). Some of these policies were rather disastrous (the Great Leap Forward and the Cultural Revolution, for starters), and in the 1970s and 80s, the government began experimenting with turning some cities into Special Economic Zones, many of which were close to Hong Kong, which was still a British possession at the time (it became a Special Administrative Region of China in 1997) and had a booming capitalist economy. Cities like Shenzhen (which is right on the border with Hong Kong) became wealthy really, really fast when they were allowed to experiment with capitalism. \n\nWhen Deng Xiaoping took power, he further liberalized the economy in order to promote national stability. He called it \"Socialism with Chinese Characteristics\", because it tried to marry the old Maoist/Marxist ways of thinking with capitalism. The most famous quote you'll hear about Deng Xiaoping's theories is \"It doesn't matter if the cat is black or white, as long as it catches mice.\" (Translation: it doesn't matter if the policy fits Marxist or capitalist ideals as long as it promotes economic stability). \n\nOf course, capitalism made a lot of Chinese people very rich (especially a lot of government types), so the economy is quite liberalized now. Anyone can open up a store or a restaurant or start a business. There are still a lot of State-Owned Enterprises (SEOs) and some holdover policies from pre-1970s Communism still around and a lot of government meddling in business (though not enough safety regulation, IMO), but in my own opinion and from my own observations, China is not a Communist country at all anymore.",
"They say it is but it's not. \n\nI don't think they even say they are communist anymore.",
"They are State Capitalists, the means of production is owned by the state.",
"The answer is it isn't, other than in name. I don't think a true communist states exists currently. When the CPC came into power, they did enforce some communist principles such as equal land distribution, but China as it exists in its current form is not communist. What communist country would let you start up a business, save money and buy a house with the money you've accumulated?\n\nIt's still called the CPC since the state follows Marxism and teaches that in school, which communism is also based off of. However, other than that and a few other policies, it would be inaccurate to call China communist. It's capitalism with authoritarianism. Anyone who calls China communist is misinformed on the topic. It's actually a very normal country to live in, no more weird or normal as the US or Canada.\n\nThe DPRK, AKA North Korea, is literally called the Democratic Republic of Korea. Would you consider them a democratic country? You might want to call them communist as well, but they've recently removed any mention of communism from their constitution and have replaced any or all Marxism with \"Juche\" theory.",
"I would say China is much closer to having State Capitalism rather than being communist. The system has changed, the label hasn't.",
"The official names of a country doesn't really mean anything. i.e. name for North Korea is Democratic Republic of NK."
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The militia thing going on in Oregon | [
"Some ranchers were convicted of arson (they lit a fire to cover up that they poached an elk on federal land). Others ranchers, the ones who had an armed standoff with the feds some time ago over unpaid fees they were supposed to pay for grazing cattle on public land, have come in with a bunch of militia buddies from all over the West to protest this conviction. As part of their protest, these other ranchers have seized an empty office in a wildlife preserve and supplied themselves to hold out for an indeterminate amount of time.\n\nIn the larger sense of things, these guys think the federal government doesn't have sovereignty over public lands they feel rightly belong to the state and to the residents of that state. They ignore generations of legal precedent and think that any public land is land they can use (and abuse) for free. As such, they think that they shouldn't have to pay things like grazing fees to the feds. They frame this as a fight against federal tyranny, but in reality these folks just think they should be able to live in some sort of libertarian system where they, for example, can use up all the water sourced from public land they want on their own ranches while other regions face shortages and that the federal government has no business trying to use that water more wisely. Expand that to include wildlife preservation, habitat restoration, hazard mitigation, etc., and you have these militia folks feeling like there's a grand conspiracy set up against them, when in reality they are simply on the wrong side of history and common sense.\n\n**Edit:** Inspired by /u/pres465's response below, I would add that this particular incident is particularly relevant to certain ongoing issues and discussions in the United States, including the war on terror, racial biases in law enforcement, and gun control, with many pointing out that if Muslims or blacks were to behave similarly, the response by both the authorities and the public would likely be a lot more aggressive.",
"A rancher and his son were previously found guilty and jailed (for 1 year, I think) for setting federal forest land on fire. They claimed it was for abatement purposes, which means they claimed it was to reduce invasive plants as the federal lands were promoting weeds and plants that were not what the ranchers wanted and plants being plants they were spreading onto their private property.\n\nSome claim they have the right to \"defend\" their ranch land from government non-intervention.\n\nThe government is of the opinion the law forbids starting fires on federal lands.\n\nThe current issue is that the rancher and son are to go BACK to jail to complete a mandatory sentence. The mandatory sentence required a much longer time in jail than the two have served.\n\nThe militia group is tying themselves to the Cliven Bundy group (Nevada rancher similarly accused of illegally using federal lands-- though he claims the government can't claim it since his family owned it first... whole other discussion) that created a momentary standoff with federal authorities last year. Bundy has become something of a messiah to anti-government groups. Bundy's son has taken on a spokesperson's role with the group in Oregon now.\n\nAs of now the militia in Oregon is threatening violence but no one seems willing to give them the spotlight or the opportunity to become martyrs. The two were found guilty by several courts, it's really just a sentencing concern now. The \"federal building\" that's been \"taken over\" is in the middle of Oregon with little or no access and virtually zero risk to citizens. \n\nThere is a curious perfect storm, of sorts, brewing in the way the President is encouraging new gun control legislation, police and media are under scrutiny for racial bias, and public perception of the President as too passive and permissive.",
"Rolling Stone has a pretty good summary here: _URL_0_",
"The American West was the last part of the United States to be opened to agriculture, ranching, mining, and forestry. At that point the Federal Government decided that, contrary to the practice in the rest of the United States, public land in the West should be used in a way that balances the economic needs of locals with the aesthetic interest of all Americans in having a pristine wilderness area. Probably this was a good policy - not just good, but unusually farsighted - however, the people who live in the area tend not to see it that way, and have been agitating for less restrictive Federal management forever. This is just a particularly crazy reaction."
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why are gun sights always, or typically, red? | [
"There not. Modern pistol sights often include color dots on the iron sights for easier contrast in lower light conditions, [but can be many different colors, and even combinations of colors](_URL_0_). Even most modern military rifle iron sights are still gun metal black. Red Dot Sights are not as used by the military as Call of Duty would have you believe. They are great for close range where faster target acquisition is essential, and the red dot contrasts with most colors you see on a battlefield. However, at longer ranges they can be a liability, as they add weight to the weapon and add further points of failure (iron sights don't need batteries, for instance).",
"On all of my guns, I have no red sights. They are all either white, glow-in-the-dark/tritium or all black. I honestly don't know of any guns I have fired (which is a lot) that had another color sight without it being aftermarket.\n\nThe only red \"sights\" I can think of are red dot scopes, which have red colored reticles because it is easier to pick up against a green background (foliage) than any other color. Green dots are another option because they can show up better in fall and winter when you're looking at mostly reds and browns."
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What is the mechanism by which daily exercise lowers blood pressure? | [
"So basically this concept revolves around the fact that your heart as a continuous pump. Your arteries contain muscles that work the same as any other in your body: the more that you exert the muscles the stronger they become. When exercising the heart and arteries are forced to pump blood at levels higher than they would normally function (i.e. an increased heart rate and blood pressure), and as a result they both get stronger. As the muscles grow stronger they no longer need to work as hard to pump the same amount of blood throughout your body. This leads to both a lower heart rate and blood pressure blood because blood can now be pumped more efficiently. Systolic blood pressure (the top number of blood pressure that measures pressure on arteries while the heart is beating) is lowered because your body no longer needs to put as much pressure on arteries to pump the blood. Also, diastolic blood pressure (the bottom number of blood pressure that measures pressure on arteries while the heart is resting) can be affected a little as well from exercise but not as drastically because the heart improvement from exercise no longer affects this pressure.",
"Blood pressure is the net result of how powerful/fast the heart pumps, and how healthy the blood vessels are. I did a lot of research on the state of blood vessels during exercise in healthy/obese people during undergrad.\n\nRegular physical activity makes your heart stronger, that now can pump more blood with less effort. If your heart can work less to pump, the force on your arteries decreases, lowering your blood pressure.\n\nBlood flows faster through the blood vessels during exercise. The increased friction forces of the flowing blood during exercise stimulate cells in the inner layer of the blood vessels (endothelium), causing the blood vessels to widen up (vasodilation). The main reason for this is to increase blood flow to the exercising muscle. It also keeps the blood vessels healthy, by keeping the blood vessels elastic. It also prevents the build up atherosclerotic [plaque](_URL_0_:) , which is a greasy mess of (calcified) fat, dead cells and white blood cells covering the arterial wall.\n\nWhat we often see in persons with a sedentary lifestyle and poor eating habits is that they have high blood sugars, high blood pressure, and their blood vessels are in a bad state (build up of plaque prevents exposure of endothelial cells to the blood stream). Now, try to look at the blood vessel as a long metal pipe. Every time when you pump an amount of water, the water pressure at the end of the pipe is just as high as the beginning of the pipe because the pipe is just a stiff piece metal. What you'll see is: water comes in the pipe as a pulse, water comes out as a pulse. When you make the metal pipe narrower in the middle (build up of plaque), you'll need to pump the water with much more pressure in to the pipe to get the same pressure at the end of the pipe. This will be your unhealthy blood vessel, causing high blood pressures (for instance 160/110 mmHg).\n\nA healthy blood vessel will be a long cylindical balloon with the ends cut off. Every time you pump water in one end of the balloon, the balloon will expand where the water bolus will be (your vessels are elastic too). This results in a more evenly distribution of the water pressure after each pulse downstream, evidenced by a more constant water stream at the end of the balloon and normal blood pressures (115/80 mmHg).\n\nWhen you're healthy, exercise won't do a lot for you in terms of lowering blood pressure. But it will do **a lot** for people with high blood pressure/diabetes/heart failure, especially in combination with changes in food intake and moderation of smoking/alcohol.\n\nDon't be a couch potato, exercise regularly and eat healthy"
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Given all the technological information we have in the world, why does YouTube just tell me "An Error" Occurred? | [
"YouTube knows exactly what went wrong. They just have no interest in sharing that with you.",
"Because what specific error occurred and why is not useful information to the end user if there is nothing they can do about it. 99.9% of users would not understand a detailed description of the error anyway."
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Stradivari violins and why they are better than others | [
"I read about this a very long time ago, but what I recall is:\n\nAs I recall, it was a *dentist,* of all people, who also happened to be an avid violinist and self-taught luthier, who managed to get ahold of some Stradivari fragments (as some of the violins have been destroyed over the years) and studied them under a microscope. What he found was that the tiny pores in the wood were first of all completely open (instead of plugged, partially or completely) and second of all that they contained countless microscopic grains of metallic salts. He surmised that when instruments made from this wood were played, they would resonate with millions of harmonic elements through the open channels, making the sound more vibrant.\n\nHe eventually determined that Stradiviari himself likely had no idea about this, or any special technique, but rather just happened to soak his starting wood pieces in water that was high in metallic salts.\n\nThe article I read (again, this was many years ago) went on to say that he duplicated the process, intentionally soaking wood parts in water he'd impregnated with metallic salts, and from that built a new violin that sounded extraordinarily fine."
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What do ISP Call Center Tech's actually do when I call them with connection issues? | [
"Ex-BT tech here, can't speak for the call centre monkeys directly but I can sort of give you a guide to what might be doable.\n\nEvery single physical line connected to a BT exchange can be temporarily routed to automated test equipment (ATE) commonly known as RAT (Remote Automated Test) for PSTN (voice phone line). This is what runs automatically when you report a fault, and the call centre can run it too. It also runs through every single line one-by-one in its spare time, usually overnight. If your phone has ever mysteriously rung once in the middle of the night, it was probably RAT.\n\nThis can tell quite a lot about the basic status of the wire - short circuit, open circuit, one leg bad, nothing connected, no dialtone coming along, etc. etc. and it can usually sort-of tell the distance to the fault to some degree (Time Domain Reflectometry for the win).\n\nBeyond that, broadband (DSL) cares more about some high-frequency properties of the line as well as being quite affected by pure distance from the exchange due to attenuation (loss). The DSL kit (and even your basic home router's DSL chipset) knows LOADS of stuff about the characteristics of the line, which frequencies it can shove down it and which ones get lost, how much interference & cross-talk there is, etc. etc.\n\nUsually the kit will try to connect at as high a speed as possible, and keep adjusting stuff to suit the conditions. It's constantly working out what it can & can't do reliably, and adjusting its parameters accordingly.\n\nNow, sometimes these algorithms get too clever for their own good and can be confused by a bad line into gradually slowing down as they decide that more and more errors occurred on various channels (frequencies) they stop using them. If you disconnect the modem & reconnect it (or the call centre reboots the DSL card at the exchange) the errors get reset and it starts from scratch.\n\nNow, it's possible that some equipment has better or alternative algorithms for poor lines (god knows they spent enough R & D effort trying for force megabits of data down a ropey old bit of copper) that can be enabled remotely, but then your cheapo home router might not, so *it* will be dragging the line down regardless...\n\nIt's also not beyond possibility that they just set a little flag on your connection that reboots it at 3am every day to reset the counters - far worse bodges have been done...\n\n...Or maybe they do nothing other than reboot the card t get you off the phone and hope you get bored of calling them back.\n\nIf your line has some fault, such as water in a joint, that isn't a \"hard\" fault (obviously dead line) but just makes stuff a little worse sometimes, things like running the remote test or disconnecting & reconnecting the DSL modem can in fact \"blow\" the fault off for a while (literally the jolt will dry water out or fuse a poor joint temporarily) - very hard to find as the fault goes away when tested, and very annoying as it keeps coming back gradually with no obvious source."
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What happens to children if they don't get adopted? | [
"They become wards of the state. Bouncing around foster homes and so forth. More often than not brothers and sisters get separated. Unfortunately it is difficult and expensive for Americans to adopt inside the US."
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Despite having similar vocal cords, why do humans have a far versatile vocal ability than other mammals? | [
"our vocal cords aren't actually that similar. They're built the same way but developed farther than other animals. if you gave a chimpanzee super intelligence, they still wouldn't be able to vocalize like we can.\n\na lot of our nuance, like writing, speaking, art, comes down to our concentration of fast-twitch muscles as opposed to brute strength muscles. These fast-twitch muscles make very tiny movements, quickly, and with reliable motions, we have them all over but mostly in our hands and our lips and faces. With these, we can speak, and can write, both very intricate movements. Our vocal cords also have these.\n\nWhat we gave up for this, is that many of us will never be as physically strong as any other ape. The strongest of us humans is a tuesday for a bonobo. I mean, look at how thin we are in comparison, our muscle mass is not that much naturally. But, we can write and speak, and I like to think that those are more powerful things than just being really strong.",
"As far as I know it has to do with the part of the brain that deals with conscious thought and personality.\n\nOur little furry friends are less developed in these areas and so have limited retaining skills.\n\nThink of it as a glass of water. The size or in this case complexity of your glass defines how much you retain.\n\nSpeech and memory centers may not be as developed yet. Also why they don't learn language as we do no matter how hard we try.\n\nGreat apes are very close to being able to speak. They comprehend language on a complex level. However due to the difference in speech centers and perhaps vocal chords they cannot express it vocally.\n\nParrots and birds mimic but do not understand what they say. It is a call to them that brings a response.\n\nThough with time birds can understand language as a concept like children.\n\nSo basically our brains just have that kick of intelligence or evolutionary advantage.\n \n\nAlas we will never know for certain if animals would speak like us if they could.\n\nPlanet of the apes goes into this in s fictional way."
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Why is a constitution important? Why were efforts made to create a EU constitution? | [
"A constitution helps set basic laws that then can later be adapted with ammendments. It is the basis for a lot of countries because it is the most basic form of written law really. Im no expert though."
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does all sound travel at the speed of sound? | [
"So I asked my personal genius; he said the speed of sound isn't constant; it varies with temperature. And it's speed is due to the way sound moves through the gases in our atmosphere.\n\n\nNo gases in the air— no sound",
"No.\n\nThe density of the atmosphere affects the speed of sound as well as the general material the sound is traveling through.\n\n[This](_URL_0_) chart shows the speed of sound at various altitudes.\n\nSpeed of sound thorough various materials\n\t\n- Rubber = 60 m/s\n- Lead = 1210 m/s\n- Gold = 3240 m/s\n- Glass = 4540 m/s\n- Copper = 4600 m/s\n- Aluminum = 6320 m/s",
"It depends on the environment the sound is traveling in. For example, all sounds go to the same speed in air. All sounds go to the same speed in water. But a sound circulating in air does not go to the same speed as a sound circulating in water. The \"more dense\" the place is, the faster the sound goes. Sorry for horrible english.",
"Sound is the motion of Air (or any other substance) expanding from the point of your mouth. \n\nOn atomic level, Atoms repulse each other if they get too close to each other (much like magnets do). \n\nThe speed of sound is the speed at which, if you were to push an object on one end of it, the impulse of the push would reach the other end. \n\nSame goes with sound, except that that push is your lips (or tongue or whatever weird way of vocal communication your planet uses), and the air around you is that object. So I say yes, all sound travels at the speed of sound.\n\n\n\nPlease feel free to correct any mistakes that I might've made in my explanation.",
"As most have said, speed of sound is constant for specific medium. If you use one medium all sound generated in it has same speed. Sound is a compression of medium that travels like a wave (like throwing a stone in water creating waves). Different sounds are actually different wave patterns travelling through medium at constant speed. Wave (compression) speed is always same, but its strength and combination with different waves can be different.\n\nAlso in solid materials sound CAN travel at different speeds. Thats because in solids you have 2 different types of waves (longitudinal and shear wave). But thats a bit above eli5 :)",
"All sound travels at the speed of sound. However, the speed of sound varies according to density of the material it travels through."
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What does refubished mean when looking at electronics? Is it worth buying? | [
"Refurbished means it has been checked and possibly fixed by somebody who is certified, usually by the manufacture, to do such work on the product.",
"It didn't work when originally built or was returned as defective. The manufacture or reseller had someone look at it and 'fixed' it so it worked and could be sold",
"It generally means that , some parts may have been replaced by the seller or the manufacturer, but it mostly works as expected.\n\n\nYou can ask the seller what was refurbished, before buying. \n\nThere are different kinds of refurbished items.\n\n\nSee here for details: (For ebay)\n_URL_0_\n\n\nIt has tips for the buyer. This is from Ebay, but can be applied to almost any vendor.",
"I've been buying refurbs for years - pcs, laptops, GPS, cell phones tv's, vcr's etc. Only had 1 problem - a Packard Bell destop that went south on me, but that might just have been the Windows Me. I'd guess I'm 30 and 1 overall."
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In court when one lawyer is doing something questionable why does the opposite lawyer have to object before the judge will take action. why doesn't the judge just stop questionable practices untill one party disagrees with it. | [
"Because that's the point of an adversarial system (both sides are supposed to have a zealous advocate for their position). The judge can't favor either side, and perhaps occasionally the side that isn't objecting may be running a xantos gambit."
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What does "brought to you by ..." mean on television shows for the company? | [
"It means that they are a sponsor of the show. They pay for ad time and product mentions.",
"It means they paid for the show to actually exist, so they get advertising in return."
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How can solid materials like glass be transparent? | [
"First of all: Glas isn't transparent for all types/colors of light (wavelengths). As you may know, light can consist of different colors, each corresponding to a certain wavelength or a certain energy. On the other hand, molecules have discrete, so-called energy levels. There are distinct amounts of energy they can absorb or emit. So, only if the energy of the light particles (photons) matches that of the molecule, then the photon has a chance of being absorbed.\n\nTo put this more in ELI5 terms: Let's say you are walking down an old mall, and come across a coin-op arcade machine. The machine only has certain slots for coins, e.g. a slot for quarters. (The arcade machine is our molecule in this case, the slots are the energy levels). Now, you have a bunch of coins (photons) in your pocket, each a certain worth (photon energy/wavelength). If you have a quarter, chances are, you might put one in and use the machine before continuing on your business. If you don't, then you're forced to walk past without leaving any money at the mall. In this case, the arcade machine might as well not exist at all, since you don't have the proper coins. \n\nSome arcade machines/molecules are more complex and accept quarters and nickels. In this case, you might leave those coins at the mall while your dimes pass through the mall unhindered.\n\nAnd that's basically how transparency works. Glass is transparent for visible light, but certain infrared and ultraviolet wavelengths get absorbed because the glass molecules has corresponding energy levels for these photons.",
"Transparency is simply the ability to let light shine through. Glass does not contain any molecules that absorb or reflect the photons that hit it, so the photons simply pass through the object.",
"Your brick wall is transparent to wifi signals, and wifi signals are basically the same as visible light. They are both electronagnetic waves but with different frequency."
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How does someone like the Long Island Medium perform her, seemingly, precise readings? Any actual insight - not just speculation - would be appreciated. | [
"Former semi-pro magician and mentalist here, I've done some of this this stuff myself.\n\nThere are several techniques successful \"psychics\" use.\n\nOne of the most common techniques is cold reading. That's where you make educated guesses about a person based on things like their dress, speech, body language, etc.\n\nAnother popular tactic is to simply get the subject to reveal the info themselves, without them realizing they're doing it. This was John Edwards' main schtick:\n\nPsychic: OK, I'm getting a dim image of a woman who is important in your life. I'm getting a C....C something?\n\nMark: Carol, my mother?\n\nPsychic: Yes! Carol! It's clear now!\n\nA common trick of faith healers is to have people fill out \"prayer cards\" on their way in, where the people say who they want a miracle for and why. Then the faith healer magically gets that information from Juh-HEE-zus-HUH!!! during the show. Hallelujah, it's a miracle!\n\nThe scam artist Peter Popoff thrived on this technique. He wore a hidden radio receiver in his ear during performances, and his wife would radio him info she'd learned about audience members, which he then revealed as messages from above. Despite being unmasked several times--including with actual recordings of the radio transmissions--Popoff continues to con the faithful.\n\nThe really sophisticated psychics will do background research on their subjects. Houdini spent a lot of his later career debunking spiritualists and mediums, but he arranged a secret code with his wife Bess that he could use just in case the afterlife was real. If a medium ever revealed the secret code, it would be proof the medium was real.\n\nAnd eventually, the medium Robert Ford DID (kinda) reveal the code in a seance. However, it wasn't the spirits that gave him the message, it was was a journalist, who wrote a book based on stories he heard from his girlfriend, a former household servant of Bess'.\n\nOf course, the popular public \"psychics\" just make a fuckton of predictions, and one or two come true by chance, so those are the ones their followers remember, while forgetting the 1000 others that didn't come true. That's called confirmation bias.",
"It's a \"reality TV show\", so \"reading the script\" is probably behind a lot of her precise readings. Leading up to getting your own TV show you can rely on the vague \"John Edwards\" type predictions, but once you've got your show you need to really rope people in. Drop all pretense of reality, and just start faking it. That's the key to success. \n\nI'm reminded of reading once that a lot of David Copperfield tricks for his TV specials consisted of things like making an elephant disappear by making the audience sign non-disclosure agreements, and then pausing the camera and walking the elephant off stage\".",
"It is a combination of cold reading, warm reading, and selective editing.\n\nCold reading is basically guessing something vague, they pretending it was more precise. \"I'm seeing...something in a uniform\" \"Yeah, my father was a theater usher!\" That person is going to remember the psychic knew their father was an usher, when they did no such thing.\n\nWarm reading is finding out actual information about people, and using it as though you were psychic. Psychics routinely have their staff interview audience members, looking for both good stories and information they can funnel back.\n\nSelective editing is simply only broadcasting the \"hits\", and pretending the misses didn't happen. Every now any thing unedited records surface (there are a few of Sylvia Browne out there) where for every person they seem to have some insight, there are a dozen ugly reads that don't go anywhere.",
"Usually its done by cold reading, you make a few educated guesses, but you are very vague with your responses, and let the subject fill in with the actual information. \"She is telling me you liked the outdoors\" or some other crap and most people will say yes i like hiking or i love skiing or something else. \"She is telling me that you regret something from your childhood\" and most people do have regrets from our childhood.\n\nThat tends to be the most common thing going on."
] |
If we need two eyes to perceive depth, how come I can close one eye and still see depth? | [
"You can determine depth with what are known as *monocular vision cues*. (basically, hints you see with one eye). Your brain has learned a lot of tricks to help decide what *might* be closer or far away. \n\n\nTexture: Things you know have lots of texture, like grass or carpet...if you know that you see a carpet, and it looks smooth, then it's likely not very close. if you can see the fibres, you know it's closer to you. \n\n\nSize: If you know that 2 things are about the same size, say 2 people...then the person that seems bigger is usually closer to you. \n\n\nAir distortion: Things that are very far away seem hazy or blurry...because you are looking through a lot of air (which may be dirty or full of water vapor). \n\n\nOverlap: If you see 2 things, and you notice that one thing partially covers the other, then you interpret the one that is partially covered as being behind the closer one.\n\n\nThere are a few more, but I can't recall them off the top of my head.",
"Think of your eyes and the object as forming a triangle. The slight difference in angle from the left and right eye helps the brain triangulate the distance. With only one eye the brain tries to fill in the missing information, it's generally close but not precise.\n\nTry this, close one eye, and extend your arm and point to an object. Don't move the hand now look with the other eye. You'll see it's off. Now look straight down the arm, you'll see it's also off.\n\nYour brain tries to fill in the missing information and guess at it's distance and location.",
"You think you can, but you can't. Close one your eyes for a few minutes and stand away from a wall. Very, very slowly, reach your finger out to touch the wall. As long as there is no shadow to guide you, you'll experience great difficulty predicting when exactly your finger will reach the wall. Alternatively, have someone hold their finger out for you and slowly reach for that with your finger instead.",
"The depth perception you get from stereo vision is only good for things up to about 20ft away. Beyond that your brain uses other visual cues like relative size, clarity, occlusion (overlap) etc. You lose the stereo depth perception, but not the other cues."
] |
Why do some medications cause different kinds of dreams? Night terrors, hyper sexualized dreams, vivid deams etc. | [
"Some medications, such as pain killers or anti-depressants, change your brains chemical makeup. It makes some parts of your brain, brain chemicals and/or hormone levels change, increase and decrease. These things are all responsible for the way you think and feel. If a medication rises certain levels in your brain then you may be caused to have these sort of dreams.\n\n** _URL_0_",
"Neuroscientists here. First off, the neurochemical mechanisms behind dreaming are not fully understood. To give you an idea of the complexity were talking here, Ambien and benzodiazepines (xanax, valium, etc.) both hit the same active site on the same GABA receptor subtype (meaning that they work, pharmacologically identically, as far as we know). Yet, while Ambien causes crazy hallucinations and bizarrely vivid dreams, the benzodiazepine class does not (normally). \n\nWhat I could hypothesises is this: if a drug has a significant effect on the norepinephrine, acetylcholine, or serotonin, it will have a strong effect on your sleep cycle, as [these particular neurotransmitters are integral to the various stages of sleep](_URL_2_). Of these, something that effects acetylcholine (like benadryl and scopolamine) would presumably have a greater effect on dream alteration, [as acetylcholine levels raise significantly during REM sleep](_URL_2_). Since acetylcholine is also integral to memory consolidation, it would make sense that a change in that system could cause distortion in the recall of your day's memories as the brain tries to rehash them during REM, which could you to experience some bizarre dreams. \n\nWhile that last sentence is *based* on factual information, it's nothing more than an educated guess. I hope this made some sense, and would gladly look into other classes of drug mechanisms to see if anything clicks. I'm very interested in this question as well, neuropsychopharmacology is what I *really* love (it's specific but exactly what your question involves). I'm typing this with one eye open, so apologize for any errors and rambling text, I'll check up tomorrow and see if I can work out anything more, particularly if you have any specific drugs you'd like me to look into.\n\nEdit: the mechanism of action of benzos vs. Ambien are actually very slightly different, they *are not* identical as I stated above, they are both agonists of the GABAa receptor subtype, but hit different subunits of the receptor. This still validates the point which I was trying to make: that neuropsychopharmacology can be very complex. It's difficult and sometimes impossible to extrapolate from molecular mechanism up to psychological experience. Thank you u/BlackTieButtPlug, for pointing this error out.\n\nEdit 2: thanks for all the interesting stories and fascinating questions, I hope my responses have been relatively satisfactory. I absolutely love extrapolating off of facts and into conjecture, it allows for more creativity than the day-to-day data collection of a lab! Feel free to continue asking and I'll respond the next chance I get. \n\nEdit 3/4: for those who want a simpler explanation, that's not really possible, as the neuropsychopharmacology of different drugs' effects on REM sleep is not simple. Here's the best I could do:\n\n***TL;DR/ELI5: We don't know. We don't know much at all about dreaming, so describing why certain drugs effect dreaming in certain ways is basically impossible. If I were to guess (based on factual information), those drugs that effect the neurotransmitters (the brain's alphabet) that are most active during REM sleep (dream time), would have the most effect on dreaming (which would be drugs like benadryl). In what specific way they effect dreaming is just too complicated to even guess at.***",
"Also, why do I get such fucked up dreams from taking melatonin?",
"It actually sounds to me like you're misunderstanding what night terrors actually are. \n\nThey're not bad dreams, or even nightmares. They're a very unpleasant experience that occurs outside of REM sleep, and are more comparable to sleep paralysis than to a nightmare. \n\nBasically, you would wake up in the middle of the night suffering from an strong fear, sometimes accompanied by hallucinations of figures, monsters, or black shapes around your room. Unlike with sleep paralysis, you're pretty much completely \"awake\" (your eyes are open and you can see your surroundings), you can move, but your brain is telling you something is incredibly wrong. \n\nUsually, night terrors end with you screaming yourself awake. However, there have been cases of people suffering from night terrors hurting themselves trying to escape from the imagined threat or monster. In one night terror I experienced, I broke my bed in half. In another, I almost jumped off the stairs. Most of the time, though, I would let out one or several bloodcurdling screams, because most of my night terrors evoked a primal, inescapable fear of death the likes of which I've never come close to experiencing when I am awake. \n\nI've never heard of medicines giving people night terrors, since this is a sleep disorder that doesn't involve dreaming. It's been associated with hormone or vitamin deficiencies in children, but otherwise its cause is unknown.",
"On the flip side, are there medications that remove dreams like night terrors? \n\nOr do those only count as anti-psychotics?",
"Fun fact: \"night terrors\" does not mean what you think it means. Nightmares are dreams that happen to be scary. They occur during REM sleep. Sometimes they wake you up. You often remember them afterwards. Night terrors are completely different. They occur when you are transitioning from deep sleep to light sleep, or vice versa. During one, you are not having a vision. In fact, your are not really having any \"thoughts.\" Instead, parts of your brain are being triggered to react in the same way they would AS IF you were scared, angry, etc. but you (your conscious or unconscious mind) are not actually experiencing any thoughts or emotions. So your child, while having a night terror, might scream, say something, or even get out of bed. Once they wake up, however, they will not remember anything (because there are no \"thoughts\" to remember), they will not be afraid, angry, etc. any longer. This is quite different from waking up after a scary dream (i.e. Nightmare). Also, waking someone up from a dream/nightmare is not usually very difficult. Waking them up from a night terror, however, can be quite difficult. Keep in mind, though, that if it is actually a night terror, they are not actually experiencing any fear, anger, etc.",
"I don't have an answer but rather an extension to the question. Why would some medicines cause someone not to dream at all?",
"Which ones cause the hyper-sex dreams, again? 'cause that sounds utterly terrible and I just want to stay away from that. Yeah, like, forever.",
"I'm here to find out which medications cause hyper sexualized dreams. For science of course.",
"Drugs are usually discovered on accident. Rx drugs that affect neurotransmitters can be agonist (^production or absorption of NT) or antagonist (opposite), just like any drug. Your brain tries to maintain a homeostasis of NT so when you take a drug that changes the levels of any NT the process of dialing back the natural production begins, hence tolerance. Stimulants such as amphetamines increase dopeamine levels and when taken in excess can produce psychosis. LSD of even the purest quality can also produce psychosis. Psychosis is relevant to your question because brain areas are over stimulated and neurons fire that shouldn't be firing, so when a schizophrenic \"hears voices\" the part of their brain that processes sound is actually firing, they aren't \"hearing\" but they have truly perceived sound in their mind. Seeking out a drug that will stimulate you will come with side effects so unless you have a disorder such as ADHD please, avoid stimulants. Except xanthines enjoy your tea and coffee. \n\nIf you want vivid sex dreams read one of your grandmas harlequin romance novels before bed. Or buy a VR headset and watch prawn.",
"I went through a weird 6 months of hyper-sexual dream states where I'd wake up in the middle of the night crazy horny. This happened nearly every night, taking no medication not even NSAIDs. Well I ended up getting some blood work done for a separate thing, and my doctor offhandedly prescribed me Vitamin D supplements when the results came back because my levels were \"kind of low\". These were large dose, 1x week pills.\n\nThe next day after the first pill the sexual dreams and the waking in the middle of the night was gone. Haven't had an issue since. Weird stuff.",
"> hyper sexualized dreams\n\nWhat drug does this?"
] |
The Birthday Problem | [
"Did you read down to where it says \"Understanding the problem\"? It is a pretty clear explanation. 23 people have 253 different possible pairings. Person #1 could be paired with #2, #3, #4, etc. Likewise, #2 could be paired with #3, #4, ... Since there are so many possible pairs, the chances that at least one pair would have the same birthday becomes large. \n \nYou need to understand that this isn't the chance that they have a *particular* day as their birthday...those odds would be much lower.",
"Let's start by looking just at 2 people.\n\nThe first person can have any birthday in the year (effectively a 365 in 365 or 100% chance). Bringing a 2nd person into it, it should be obvious that the 2nd person has a 1 in 365 (to keep things simple, we're ignoring leap years) chance of having the same birthday as the first person.\n\nAnother way of saying this is that the 2nd person has a 364 in 365 chance of having a different birthday. In other words, this person has a [99.73% chance](_URL_5_) of having a different birthday.\n\nIf a third person walks in, they have a [363 in 365, or 99.45% chance](_URL_2_) of not matching either of the first two people's birthdays.\n\nTo get the likelihood of these 3 people having *different* birthdays, we multiply the numbers together. [1 * (364/365) x (363/365) = 99.18% chance](_URL_1_) of all having different birthdays.\n\nTo get the probability that 2 or more of these 3 have the same birthday, we can simply subtract the all the fractions multiplied together from 1 (or the percent from 100%, which is the same thing). So, a 99.18% chance of everybody having *different* birthdays means there's only a .82% (82 hundredths of 1 percent!) of 2 or more of these 3 people having the *same* birthday.\n\nTo get the probability for any number of people (let's call that number *n* people), then, you're going to have to keep multiplying fractions in this manner:\n\n1-(1x(364/365)x(363/365)x(362/365)x...x((365-n+1)/365)\n\nThe fractions multiplied together, remember, will give us the probability of everyone involved having *different* birthdays, so the \"1-\" at the beginning turns it all around and will give us the probability of at least 2 people having the *same* birthday.\n\nNow, we are multiplying large percentages here: 99.73% * 99.45% and so on. This is actually the same as multiplying decimals: .9973 * .9945, etc.\n\nObviously, these numbers can remain large, as 99% of 99% is still quite large. But we're also multiplying a percentage for each person, so it begins to shrink as more people are brought in. For example, if you [multiply .99 times itself 20 times, you're already down to just over .81](_URL_0_).\n\nIn the actual birthday equation for 23 people, we're multiply numbers ranging from .9973 (364/365) down to [.9397 (343/365)](_URL_4_).\n\nWhen all those numbers are multiplied together, you wind up with only about a .4931 probability (49.31% chance) of everybody having *different* birthdays. Subtracting that from 1 means there's a .5069 probability (50.69% chance) of at least 2 people in that group having the same birthday.\n\n[Here's a graph of the percentages as the number of people increase from 1 to 60.](_URL_3_) Notice that, by the time you get to 60, you're up in the 99% range of having a match, and it just inches closer to 1 until you get to 366 days (which is a guaranteed match - remember I said we were ignoring leap years)."
] |
What is a fiscal year and why do we need it. | [
"Fiscal years are used by government and some businesses (usually mid-to-large businesses) concerning money. As to why they don't use a traditional calendar year, [here is one reason](_URL_0_):\n\n > December is a really bad month to try to close out an entire year's accounting books. Accountants and execs are on vacation for large parts of the month, most retail stores are flooded with revenue (and then contra-revenue as items are returned) that takes time to account at the store level and then filter up to the corporate office, etc etc. It also doesn't tell the whole story for most retail outfits; December sales are usually inflated by purchases that are then returned in January after all the hullaballoo. As a result, a fiscal year end in January or even February keeps the entire season's revenues and expenses in one fiscal year.",
"A fiscal year is an accounting tool where you can shift when your year starts for accounting purposes. For some companies, the calendar year is inconvenient to use, so they'd rather manage their finances according to a different year. For instance, if you're a company that sells school supplies, reporting your sales according to calendar years is annoying, because you'll be reporting half of one school year and half of another, so you might decide that your fiscal year is going to run from July to June instead.",
"A fiscal year is a way to financially split up a period in roughly a year. It may be aligned with an actual year or it may be easier to schedule the extra work which comes with closing and opening a financial year to other times. The main reasons you would want to work with financial units is so you can do analysis and planning on your entire business at once. A big company might not know how much money it have at a given time. If someone have unclaimed expenses or there is an unregistered sale then the company do not know how much money is in that. There is a lot of other reporting and calculations that needs to be done before a company knows how much money it have. So it does all this at a given time each year. It would also make sense to do comprehensive planning which would involve a lot of input from the different departments on what they need and an overall plan on what the company should do and where to invest the money. You also have smaller units like fiscal quarters and fiscal months that would serve similar roles but on smaller scales.",
"The idea is you want the end of your year and the start of the new one to be during the quietest time in your business cycle.\n\nIf you sell snow shovels for a living, whether a blizzard hits on the last week of 2016 or the first of 2017 can skew sales from one year to the next. Much better to end your fiscal year on 6/30, instead of dividing up your busy season."
] |
How do the Star Wars' (et. al.) Expanded Universes work? | [
"Most of your questions are answered on the [Wikipedia page](_URL_1_) for the Star Wars Expanded Universe.\n\nBut to paraphrase some of it, and to answer a few of your questions:\n\n1. They do have a hierarchy. If Lucas says it, it is considered **G** level, and therefore canon. If it was on TV it is **T** level, which is below **G**, but above **C** which includes most of the books and games. Check out the Wiki for the rest of the levels.\n\n2. They do have a bible of sorts, more aptly titled [The Holocron](_URL_0_). Which is a database of all characters and events considered Canon. It is kept private as it contains events in planned releases as well.\n\n3. It is a pretty enormous undertaking to try to keep the entire Universe from containing any contradictions. Unfortunately there are certainly inconsistencies. I typically just try to appreciate each work individually, and not get too bogged down in those sorts of details. For instance, they seemed to have taken a long time to figure out what the hell Leia was talking about when she said that Obi-Wan fought with her father in the Clone Wars. Which side were the clones on? Did both sides have clones? What was the war about? I've even heard that Lando was originally supposed to be a clone, but they just dropped that part. The concept of what it means to be a Jedi or Sith has evolved greatly. The word \"Sith\" was never even spoken in the original trilogy.\n\n\nIn the recent reissue of Timothy Zahn's \"Heir to the Empire,\" the author makes frequent annotations that explain discontinuities. Some are interesting. I actually stopped reading them because they were distracting and really ruined the magic."
] |
How a nuclear power plant works. | [
"Nuclear power works by the fissioning (splitting) of uranium-235 atoms with neutrons. Every atom that fissions releases a little bit of heat and, on average, 2.5 new neutrons. This means it can be an exponential process, rapidly generating a lot of energy.\n\nThe nuclear core in most power plants (i.e. Pressurized Water Reactors or Boiling Water Reactors) is made of rods of low-enriched uranium. This means that the amount of the isotope U-235 is raised from < 1% (natural uranium) to 5% (the rest is U-238, which doesn't fission). By raising the level, this means that they can use regular water as a \"moderator.\" The moderator helps keep the reaction going by slowing down the neutrons produced by the U-235 fissioning — U-235 fissions more readily from slower neutrons, which means you need less of it to keep a reaction going. \n\n(The reasons for this are interesting but perhaps a bit beyond explaining this at an ELI5 level, so just take it on faith that being in water makes the reaction work better. Note that this kind of reactor, one that uses regular water, is called a \"light water\" reactor, to distinguish it from reactors that use \"heavy water\" — deuterium oxide. Such reactors do not require enriching the fuel, but are generally not as good for power purposes.)\n\nIn a nuclear bomb, you want a nuclear reaction that releases all of the energy very, very quickly. In a reactor, you don't want that, obviously. You want a reaction that goes from zero to \"pretty big\" fairly quickly, but then stays more or less constant. The way to achieve that constancy is through both engineering the reactor so that it is harder for it to fission like crazy (there are various ways to do this), but also through control rods. These are rods made up of substances that readily absorb neutrons, like cadmium or boron. So one way to think of a reactor is as a neutron-producing machine. You want a good \"neutron economy,\" where you have enough neutrons to keep the reaction going, but not so many neutrons that it gets out of control. The use of control rods is the main way that the neutron economy can be affected directly by the operators, either dialing it up or down as they need to. There are other engineering tricks for getting more efficient reactions out of less fuel, like having neutron-reflecting material surrounding the fuel.\n\nAs a consequence of all of this fissioning, the reactor generates a lot of heat. Depending on the type of reactor (i.e. Pressurized Water Reactor or Boiling Water Reactor), the heat is siphoned out of the core in various ways, then turned into steam, then put through a turbine. \n\nTo add and remove fuel, you shut down the whole reaction (insert all of the control rods). Then you have an remote-automated machine that removes those fuel rods. This all takes place under water, because after being inside the reactor for any appreciable amount of time, the fuel rods get very radioactive. The rods are then transported (again, still under water) into a separate spent fuel pool (usually near the reactor building), where they sit for about 5 years or so. This allows them to get rid of the worst of their radiation and they can then be removed and put into dry cask storage. \n\nAdding new fuel is not such a big deal, because the fuel is barely radioactive at all before it has been inside of a reactor. They have ways of removing the tops of the reactor vessels and machines to insert the new fuel rods.\n\nIn many localities you can get a tour of nuclear power plants just by asking nicely. I heavily recommend it, because until you see it in person, it is easy to abstract all of this into the simple flow-chart diagrams you'll find on Wikipedia or the like. In person they are very impressive, very large facilities. I got to tour the Seabrook Station Nuclear Power Plant a couple of years ago and found it quite interesting, both because of its size as well as the boring banality of it. Most nuclear reactors are deadly... boring, and operate under completely uninteresting conditions nearly 100% of the time, and that, paradoxically, makes seeing them in person kind of interesting.",
"Nuclear power works like any other boiler - in a thermal cycle, water is boiled into steam, which transfers fluid to mechanical energy in turbines, then the water is pumped back up to pressure and fed back into the reactor.\n\nIn the core, heat is generated by the fissioning of Uranium atoms. U-235 is a *fissile* fuel, meaning the introduction of one neutron tips it over instability and it breaks into fragments. Those fragments carry with them a large portion of the fission energy in the form of kinetic energy. The energized, heavy fragments (roughly 1/2 the mass of Uranium) collide with other particles in the fuel element and it heats up...a LOT. The fuel is composed of Uranium pellets in the form of a ceramic, such that the fuel will not melt under these high temperatures. Uranium content in the fuel is enriched, or concentrated, to a certain percentage of U-235. The degree of enrichment dictates how likely the fuel is to fission, due to the higher fissile isotope content. \n\nUpon each fission, multiple neutrons are released along with the heavy fragments that deposit their kinetic energy (heat generation). Those fission-born neutrons are a new *generation* of neutrons, and lead to subsequent fissions in the core. That process of neutron absorption-fission-neutron release-neutron absorption-fission...comprises the nuclear chain reaction. Heat is continuously produced through this process, and is directly proportional to the number of fissions that occur.\n\nBefore the next generation of neutron can lead to another fission, they must be *moderated* or reduced in energy. When born by fission, the neutrons have high kinetic energy as they are ejected from the nucleus, on the order of 2-3 MegaElectronVolts (MeV). Those high energy neutrons have a very low probability of causing subsequent fissions; essentially they just fly right past the target nuclei. To increase that fission probability, they have to be brought down in energy (moderated) to < 0.1 eV. \n\nSmartly, moderation occurs when neutrons interact with water. The neutron collides with the hydrogen atom in water, transferring some if its energy to the water molecule, bringing it down closer to where it can be absorbed. Simultaneously, the water heats up and across the entire core the bulk process leads to steam generation. Controlling power in the core is a balance of neutron content and moderation; how many neutrons dictates how many fissions occur, and moderation impacts the likelihood of those fissions occurring.\n\nAdding and removing fuel must be done when the reactor is cold, essentially turned off. By turned off I mean the fission chain reaction stopped, therefore fission power will not increase for energy reason. Utilities that operate the plants swap out \"burnt\" fuel bundles that have depleted U-235 fissile content. They do not produce as much heat as fresh bundles because the number of fissile atoms reduces as the fuel is burned. Huge cranes lift and rearrange the fuel bundles according to a precise analysis of optimal positioning. Fuel bundles, AKA assemblies, are a bunch of fuel rods held together by spacers. Rods are long pins packed with fuel pellets where the heat is generated.\n\nPretty simple, right? ;)",
"In a reactor, neutrons are used to split atoms to release energy and heat. When you split atoms, you also get more neutrons out, which allow the nuclear reaction to continue on its own.\n\nThe heat is used to boil water, either directly in the reactor, or somewhere else. The boiled water/steam is used to turn a turbine.\n\nRefuelling of nuclear plants is performed every 18-24 months. They shut down, cool down, disassemble the reactor pressure vessel, pull out the reactor internals, and shuffle the fuel. About 35% of the fuel (on average) is replaced. Then the reactor is reassembled, pressure tested, and restarted.\n\nTo start and stop the reactor, control rods are used. The control rods have material that absorbs neutrons. By taking them out, they absorb less neutrons, and allow the nuclear reaction to become self sustaining. By putting them in, the neutrons in the core get absorbed, until the reaction is no longer self sustaining and shuts down. The control rods are hooked up to a reactor protection system which looks for abnormal conditions in the plant, and if it sees them, shuts down the reactor within 3 seconds by releasing the rods so they can get pushed into the reactor. \n\nOnce the reactor is online, power is controlled in most reactors by changing the amount of cooling to the core. For pressurized water reactors, by removing more steam, you cool the water down more before it goes in the reactor, which increase power and removing less steam means the water returning to the reactor is hotter, which reduces power. For boiling water reactors, we adjust how much cooling water we push through the reactor. Pushing more cooling water increases power, and less cooling water decreases power.",
"Nuclear fission(at least the type we're after) releases energy because the energy stored in the bond of the two resultant particles is less then the energy stored in the original atom. Thus this energy is released.\n\nThe splitting of the atom is mediated by a fast-traveling nuetron. The element used in reactors(uranium 235) will absorb that nuetron and turn into uranium 236, which is unstable. When it decays, it will release more neutrons, which will make more fission, ect.\n\nIn a nuclear reactor, we don't want this chain reaction to spiral off. Thus we do 2 things-use more U-238, which turns into the stable U-239, and use things which will absorb nuetrons, like heavy water or graphite. Whereas in a bomb things like beryllium are used to reflect the neutrons back into the uranium.\n\nGraphite rods can be inserted into the uranium to increase or decrease the rate of fission-which is how we make a controlled release of energy versus an explosion. The power is ultimately turned into electricity with the good ol' steam turbine."
] |
What is happening with the Ebola patients "rising from the dead"? | [
"They aren't. The people either weren't actually dead, or the stories are complete fabrications. No zombie apocalypse for you.",
"Considering death is usually pretty final and that we're dealing with a second-hand accounts from a 3rd-world country, I'm going to err on the side of 'they're probably wrong'.",
"Magical thinking borne out of fear and lack of information. Can you please link some of the instances of this?",
"Found this on Newsweek: They are not a tabloid.\n_URL_0_"
] |
Why can't we transfer scents the same way we transfer images? | [
"Scents are actual physical particles moving in the air. Transferring a scent then requires that you actually move physical things, or that the receiver have the necessary components to manufacture scents when sent instructions.\n\nSmell-o-vision is certainly possible. It would just require scent compounds that would need to be replaced as they were used up. Currently there just isn't enough demand for smell-o-vision to support that.",
"Smell is caused by receptors in your nose binding to actual molecules released by the substance that you're smelling. To transfer scent, you'd need to invent some sort of detector that could detect the hundreds of thousands of different molecules that you can smell, and some sort of device that had a stockpile of hundreds of thousands of different molecules (some of which are very volatile and can't easily be stored), and refill it every time one of the molecules was running out.\n\nWith images, though, you only have to detect and emit one type of thing: photons. And you only have to care about three different wavelengths of photons. The whole process is much, *much* simpler."
] |
how a crackws touchscreen can work in some areas but not others on the screen | [
"The glass part of the screen isn't what makes it \"touchable\", there is something under the glass called a digitizer that accepts your skin as an input through the glass. If this digitizer isn't broken due to dropping, or physical damage than the area will still accept input"
] |
How do shows like Masterchef conduct so many interviews of the cooks before something is about to happen? | [
"Just from watching, it definitely seems that the interviews are conducted afterwards. Possibly long after, when the producers develop a storyline from the footage they shot. \n\nYou can watch closely for hair, makeup, & clothing changes to see that it is definitely not \"in the moment\".\n\nOf course, that means they already know the outcome and are just acting. Maybe that ruins the magic? Sorry."
] |
When to use "myself" in a sentence and when NOT to. | [
"Unfortunately, it is grammatically correct. *Myself* is a reflexive pronoun, but can be used as an intensive pronoun (adds emphasis to a sentence.) People hate it for the same reason they hate exclamation points. While technically okay, they're unnecessary and are only used to make your sentence seem more dramatic."
] |
How an Action Replay works | [
"The code you enter translates into instructions, these could range from \"only do the next instruction if a certain button is pressed\" to \"update the figure for health and set it to 9001\".\n\nThese instructions are then inserted into the instructions sent to the games console at regular intervals to make your cheats work."
] |
how complex mechanisms like the eye evolved. | [
"Well the eye first started off as just a patch of light-sensitive cells, which would be beneficial to organisms that needed to know where light and dark was (either to stay warm or to avoid drying out).\n\nOver time, this patch of light sensitive cells began to pit. The indentation meant that the cells could now differentiate direction based on what portions of the cells were exposed to light. This allowed for not just knowing whether there is light or not, but what direction it's located relative to their position.\n\nGradually, this pit would deepen, allowed for better perception of light orientation. A pinhole would eventually develop, allowing for very fine focused perception of light and even the beginning of rudimentary image perception. For the first time, organisms could begin to 'see' more than just light or not. Specialized will mutate and evolve over thousands of generations, allowing for greater and better perception of light and objects, including structures such as a lense, more specialized receptor cells, and eventually muscular control.\n\nEyes have proven to be so useful to organisms, that scientists believe that complex eye structures have evolved independently around 50 to 100 times in different 'lines' of organisms.",
"Cosmos just explained this pretty well. As life that began underwater started to get closer to the surface, thus becoming more and more exposed to light, something developed in some of the organisms that was sensitive to this light and those organisms were naturally selected because they tended to live while those without the light sensing thing did not. Then when all of the organisms had light sensing things, speed and clarity became important to outlive everyone else, so the light-sensing thing developed a little more. But the way an eye is useful underwater is different from the way an eye is useful on land in direct sunlight, so once these organisms came out of the water for good, more and more developing to the eye structure was piled on to what had already worked underwater...which is why you'll see some legacy qualities to our eyes today that make our vision suboptimal, because they were built on a foundation of underwater vision."
] |
where bitcoins come from and why everyone doesn't just mine bitcoins for profit | [
"Basics first. \n\n* For each block (set of transactions) there is a set bitcoin reward. \n* Each block is a race to see who can solve it first. \n* Only one person/group can claim the reward. \n\nNow, knowing that, we can also add the following:\n\n* Mining is difficult\n* It takes electricity (sometimes a lot) \n* Electricity costs money (in most places) \n* How difficult each block is adapts to the size of the network. \n\nSo, what you end up seeing is a sliding scale where the average cost of electricity needed to do the calculations matches the size of the reward. Or:\n\n Average(cost of electricity) * portion of network rewarded = Average(size of reward) \n\nSo if you have a higher electricity cost in your area, you might not make a profit, since the calculation is based on an *average*. This pushes the average cost for the network down, and further drives out high-cost areas, making a sort of cycle. \n\nNow, this ignores the price of hardware, so it's not totally accurate, but it gives a good picture."
] |
Why do some manufacturers print their own prices on items? | [
"to prevent strors from over inflating prices. They know how much thier product costs. if someone is selling it for more, the customer knows its not Arizona and does not have those hostle feelings. keeps everyone in check.",
"Manufacturer Suggested Retail Price (MSRP): what the manufacturer *would like* a retailer to sell their product for. Retailer needn't abide by it which is why 99¢ Arizonas might sell for more and why most items sell for less. Ex.$100 shoes on sale for $79.99. Varies depending on deals struck between vendors and retailers. \n\nMinimum Advertised Price (MAP): the lowest price a retailer can *advertise* a product for as per its agreement with the manufacturer. Ex. Ad language like, \"At a price so low we can't even print it!\" Useful in keeping brick and mortars competitive with online sellers and helps maintain the integrity of brand image.",
"Arizona does it because it's one of their core marketing points. They're trying to place pressure on retailers to sell it at that price.\n\nOther companies, like chips , do it for convenience. It's a lot easier for them to print a price on the bag than it is for the store to put a price tag on it & crush all the chips. A store can always mark other prices or buy unpriced merch."
] |
Why are posts on Reddit archived and cant be voted on? | [
"Reddit posts are meant to be contextual - they are interacted with by users in real-time through comments, replies, and up votes. These interactions reflect the situation at the time of the post - comments on the Greek referendum, for example, are based on the relevant information users have now, in June/July 2015. \n\nIn the future, it may be interesting or informative to look back on posts as what they are - snapshots of perceptions and opinions on a certain issue at a certain time. Thus, posts are archived so that perceptions and opinions of what will be the future do not influence the snapshot of what happened in the past. For example, we will be able in a year to go back and look at what was said about the Greek referendum, without sifting through comments that were added months later once more information was available. \n\nAlso, changing perspectives can mean that people go back and try to downvote or upvote posts/comments that are no longer true or are now more relevant. This is not really reflective, however, of the post at the time of submission; sure, we may know in a year that the Greek referendum being a resounding 'No' was a great thing, but that's not what people are saying right now; \n\nBasically archiving allows for accuracy of record-keeping for the future, and protects people from mass upvotes/downvotes due to future events. \n\nI also believe it reduces the server load for reddit to save a static thread rather than keep it dynamic, but I don't know the details as to why that's the case (hardware is not my area of expertise!)."
] |
Why is fighting allowed in North American professional fighting? Is it just for show, is it planned? What benefit does a player get out of fighting when they could easily be injured as a result? | [
"I don't understand your question. Professional fighting is a legitimate sport and the necessary precautions are taken so the fighters don't get seriously injured. Sometimes they do, but that's no different from other sports.\n\nIn fact, fighting is a relatively safe sport. Basketball, soccer, ice hockey and football cause way way more injuries on average.",
"Did you make a mistake in your question? You asked why fighting is allowed in fighting.",
"You're gonna have to break this down a bit. Are you asking why pro(boxing/MMA) fighters fight? Or if pro wrestling is real?"
] |
Why is my internet worse at nighttime? When its day time, multiple people are using it (family) but when its nighttime and its just me, it's painfully slow. | [
"Not a lot of details offered to give a clear explanation, but likely your internet is limited by the hub in your street (so the number of other people in your street also using the internet at night) and the connection your provider has with the world.\n\nWhen it is nighttime in the US, Asia and Europe are active.",
"As /u/baldhermit said, it all has to due with how many people are connecting to the service point for your neighborhood. If most people are at work/school during the day, you get access mostly unimpeded. Once the kids get home from school and hop on youtube and spotify, it starts to bog down, and the later hours when the neighborhood nerds start torrent downloads things can really go to hell in a hand basket if your node is already oversold and struggling.",
"Well when you use it at night to watch porn you think you're alone. However everyone ese is also watching porn. All of that porn slows shit *down* which results in a buffering message right before the tentacle can finish going up Saber's body and out ofher mouth to slather her chest in tentacle juice. I used to have this exact problem, so I got more RAM for my router. It ended up curing cancer because everyone knows that more RAM is the answer to all problems."
] |
We attribute pollution to death tolls. Why can't we sue or press criminal charges against the united states government for being complicit in these deaths? | [
"> We attribute pollution to death tolls.\n\nFirst of all, you have that backwards. \"To attribute A to B\" means that B causes A, and I'm pretty sure you don't mean that death tolls cause pollution.\n\nSecond, expecting the government to be responsible for deaths caused by pollution would be like expecting the government to be responsible for deaths caused by car accidents. The government isn't going to be able to just make driving cars illegal, because it would destroy the economy. Likewise, trying to make pollution totally illegal would destroy the economy, because some level of pollution is an unavoidable side effect of industry, and so the only way to make pollution illegal would be to make it illegal for manufature most products, or for most power plants to produce electricity.\n\nAnd third, you can't sue the government unless they *allow* you to sue them. This is called [sovereign immunity](_URL_0_)",
"According to the doctrine of [sovereign immunity](_URL_1_), the US government cannot be sued, unless it consents to be sued."
] |
Why churches and banks almost always include the word "first" to their names. | [
"To establish that they are the first church or bank of that type in a given location. It indicates to people who want to use them they are an older, more established organization.",
"The \"first\" this is motivated by being the first in a region; eg, the \"First Baptist Church of Hartford\" is literally the first baptist church built in Hartford. There are, especially in bigger, younger cities, oftentimes multiple churches after that (second baptist, third baptist, etc).\n\nThe rationale is it's a simple name that communicates your position in the community, and then 100 years later people are like, \"Whoa, that's the first baptist church in Hartford? What a fine, upstanding institution to have survived all these years.\"\n\nBanks are similar, but I don't know that I've ever heard of a \"Second Bank of Hartford\" - if only because it implies followership. I would definitely want my bank to be the First Bank in a city, though. It would imply, again, a connection with the place that I think many customers would find appealing.\n\n_URL_0_"
] |
The science behind two mirrors facing each other, and the amount of images or frames of reference of real life created? | [
"be careful bro... you never know. you might like pull a Doom-esque scenerio, and accidentially open a portal to hell if you witness what is at the end of the endless mirror chain."
] |
Why does water feel colder after chewing a minty gum or mints? | [
"Menthol (a compound in mint) activates your temperature receptors (which normally only get turned on when exposed to low or high temperatures), which creates the feeling of coldness."
] |
How come Trix stopped making the shape cereal? why is it only circles??? | [
"Well, young 'un, back in the day, *way* back in the day, in the dark ages before the 1990s, Trix *were* round. So, really, what they are now is what they should look like, not your hippity hop fruit shapes. Now get off my damn lawn, you punk kids, or I'll turn the hose on ya ag'in.",
"I would speculate that it is a cost issue. Or time.\n\nImagine you had to shape a bowl of Trix for yourself. To make all of those shapes with different colors would take a while, but if you only had to make the spheres, then you would be done in a third of the time, probably saving you some materials in the process.\n\nDo note that this is just my common sense and intuition, as I don't know the real reason for sure.",
"They still make them with shapes.\n\nSource: I''m eating them right now _URL_0_",
"From the [Wiki](_URL_2_):\n\nThey started out as spherical cereal pieces, but in 1991, they were changed to puffed fruit-shaped pieces. In 2006, they reverted to their original shape in the United States and several other places; in Mexico they have kept their fruit shape.\n\nThis is the best answer from a [Yahoo Answers](_URL_2_) thread:\n\nTrix are now in fact back to their original shape. The cereal was first sold in 1954 in what is now its infamous puffed ball shape. It wasn’t until 1992 that it became fruit “shaped”. Until I saw your question posted here I was unaware that they had become round once again. My curiosity bit me, and I started poking around. It seems that there is quite an upset in the whippersnapper community. They do not know that, just like the Coca Cola company, General Mills made a mistake and had to bring back the original favorite (in 1997). Now we have our Trix “classic”. There are actually people rejoicing over the return of the balls. There is also a petition on the web encouraging the return of the fruity shaped ones (too bad it only has seven signatures). I had no idea there was such a fervor. Anyway, I can’t answer the question - and apparently neither can anyone else (including responders to the other 4 people who have asked the same on Answers). The closest thing I could find was a suggestion that the new shapes, due to a different molding process, deemed the pieces less digestible (believe that if you want). Everybody else says that General Mills has clammed up and will not divulge the reason.\n\nMy personal guess would be that it was a way to save money. They produce Kix as well, and they are also round. Perhaps it was a way to save money by using the same machinery to create the cereal shapes.",
"I think it is a marketing ploy. When I was a kid they were circles. Then they started making the new fruit shapes. I wrote the company and asked them to please start making the circles again becuase they fit onto my spoon better.... they didnt. But now suddenly, when I walk down the cereal aisle Trix is advertising the 'new circles' shape. I think they will introduce the fruite shapes when this generation of kids grows up as a 'new thing'"
] |
General Government Net Debt Infographic - What does it mean? | [
"If you worked hard last year and earned $80,000, but you owe $60,000 on your credit cards, how secure in your finances would you feel? \n\nThat would be 75% on this chart.\n\nWhy isn't Japan also in trouble? Because there's more than just this one figure that decides when a crisis is happening. (For example, change \"credit cards\" in the first sentence to \"house mortgage\", and suddenly things sound ok again)\n\nELI5: You owe almost your entire pocket money for a year to your friends. They thinking of not loaning you money for lunch next week. You might get very hungry.",
"You may wonder *why* governments even get in debt in the first place, and why some countries do better than others. It's best told by analogy.\n\nSuppose you are a young college grad going into med school. Your income for the year was $20,000. But you owe $20,000 on your student loans. Your debt ratio here is 100%. Is that a good thing? Well, it can be, but it all depends on the future...\n\nLets say after four more years, your debt piles up. But then you land an awesome medical job. Your income now is $100,000, and your debt is $50,000. Your debt has more than doubled, but your debt ratio is down to 50%! That's good. In other words, sometimes going into debt can be a *good thing*, as long as you know your future income can make your future debt situation even better. \n\nBut it's not all about debt ratios. It's also about the ability to pay it off. Any money a country overspends for the year must be borrowed from others. Those other lenders get to effectively decide the interest rate on the repayment. \"Hey America, you need $1.4 trillion? I can help, I'll give you $10 million now, if you promise to give me $10,010,000 five years from now.\" In that story, the interest rate is 1%. America sees those interest rates and says \"Wow, this is a deal for us! We're definitely going to be 1% bigger five years from now, so from our perspective, it will feel as if we pay back less than we were lent! Oh ya, lets do it!\". So the US is currently $1.4 trillion in debt every year, because our interest payments are so dang low. Our debt to ratio is massive in comparison to the past, but, our ability to pay off loans is surprisingly sustainable...for now...because rates are low. \n\nThis is where the bottom of that graph comes in handy. And this is where Italy and Greece got in trouble. Their interest rates were hitting really bad levels of 7%. Around that level, the interest rate is so massive, countries just go deeper into debt each time they borrow. But their voting public insists the government continue spending. So they were borrowing and treading water. It was far from sustainable. All played out, the government would borrow more and more, interest rates would rise, and eventually the rates would be so high, and government revenue so little in comparison, that Italy and Greece would simply say \"Sorry folks who lent us money, we have no money to give you back.\" That's near doomsday. Lending to these countries would stop, and these countries would be forced onto a balanced budget and almost certainly a recession accompanied with it. This is why Germany stepped in and said \"Here are some loans, fix your budget mess too please.\" The rest of the world saw this, and the interest rates dropped to more reasonable levels...so far. \n\nOn the opposite end, look at Japan's faint pink around 1% on that graph. 1% is wonderful. At that level, 130% debt to GDP is very easy to manage."
] |
These week to week worldwide protests against goverments. | [
"Protests are common in many countries nearly all the time. Which ones are you referring to?"
] |
Why can't we remember memories when we were a infant? | [
"our brains are still developing the ability to interpret and store information gathered from the sense, so the structures required to store long term memories don't exist yet."
] |
What does a president do in his free time? | [
"Many read or play golf. Some spend time with their families. GWB liked to go to his ranch in Texas. \n\nMany presidents (avoiding politics) are fairly intelligent individuals who enjoy any number of activities. The problem is that the job of president offers very little in terms of true free time and due to security doesn't usually allow much access to \"regular forms of recreation\" that a regular individual might enjoy (for example, a president can't just decide to take his/her dog to the local dog park on a random nice sunny day)."
] |
Why isn't dodgeball a popular professional sport? | [
"There was an NES video game in the 80s that was an international tournament. Of course Russia was one of the final bosses, cause cold war.\n\nIt was amazing in the ways pro Dodge Ball could be.\n\nIt would need sponsers, eventually.\n\nStart up some local tournaments. Heck, check for a subreddit. There was a paper,rock,scissors world championship.\n\nYou might have to be the one to get the ball rolling OP.\nI don't see any reason except that it's not done yet.\n\nAnyone?",
"I have no idea, but if you could get the GOP to use it to determine their Presidential candidate it might catch on."
] |
Why is abortion a religious issue? | [
"The Bible doesn't take a position, but modern religious leaders do, and they're vocal about it. Many folks take their cues about political positions from the teachings of their religious leaders.\n\nPlease note: I'm *not* saying that all people take political cues from religious leaders. Just that of the ones whose views on abortion are related to their religious beliefs, it's likely that they're members of a faith that's vocal on the topic.",
"You really answered your own question here. Because the bible doesn't declare fetuses humans or not, there is debate. If it's a human, it's taking a life (which breaks a commandment). If it's not, you're not breaking a commandment and therefore it's \"ok\".",
"The verse most often referred to when discussing a Biblical stance on abortion is:\nPsalm 51:5 Surely I was sinful at birth, sinful from the time my mother conceived me.\nThe logic in using this verse as biblical opposition to abortion is that if a human can be inherently sinful from conception, it must also be a \"life\" or possess a soul.",
"I guess you could give both a a religious and a political answer to this. I'll go for the latter. Like so many things in society it's about power and control: in order to stay relevant in an increasingly secular western world religion needs issues it can try to push on society and rally it's followers around. If it doesn't it becomes a boring social club that people only care about on Sundays. Kinda like the church of England. Or Sweden. In the end people stop attending altogether. \n\nSo abortion has become one of these issues for several reasons; one is that it can be used to construct a very easy to understand binary argument, either you're for it or you're against it. Another is that it mainly involves women's rights which have generally been a favorite of the church to focus on because they're easier to bully than men. But the biggest is probably that it involves a large scale killing of what can be argued to be human beings. If you can convince people that these fetuses are indeed humans worthy of life then you have an issue of large scale murdering, which is a sure way to upset a lot of people.",
"Generally religious people tend to oppose abortion more and the nonreligious tend to support it more, but there are religious pro-choice people as well as secular pro-life people. Catholics for Choice is one of the former. Secular Pro-Life and Feminists for Life are some of the secular pro-life folks. They don't rely on religious reasons for why they think abortion is wrong. I'm not sure what Catholics for Choice believe, but by definition they must think there's no good religious reason to outright ban abortion."
] |
Surely someone must know: How do blind people use those bird chirping noises to cross the street? How do they know it's not for the kitty-corner side of the street? | [
"Bob is walking north when he approaches an intersection that he knows has an auditory signal. He wants to continue north. He presses the button and listens for the next auditory signal. There is one particular sound that's used for north-south intersections and a different sound that's used for east-west intersections. When Bob hears the north-south signals, he continues his north-bound walk."
] |
How does the Leuxs hoverboard actually hover? | [
"The board itself is a superconductor, kept super-cold through liquid nitrogen. This causes it to magnetically repel ferric metals.\n\nThen they stick it on a steel platform so it repels the floor and hovers."
] |
Why is .3^.3 larger than .4^.4? | [
"The answer is **0.367879441171442321595523770161460867445811131031767834507**\n\nDisclaimer: IANAM\n\nWhy is an interesting question to answer! I'm assuming you want an intuitive answer as the mathematics is self-evident. I'll try to do this without using [logarithms](_URL_0_), though that's probably a mathematicians preferred way of reasoning around exponents.\n\nWe're talking about x^x between 0 and 1, we can think of the exponent x as a fraction 1/z. So x^(1/z) where x=0 to 1, z starts very large (1/large-number≅0) and ends at 1 (1/1=1). \n\nWhy do we want to do this? because remember that x^1/z is the same as taking the z-th root: ^z √x\n\nLet's start with x=0.5, which means z=1/2. So ^2 √0.5, Square root! There's something we're familiar with, **we need the number multiplied 2 times** to create 0.5: which is ~0.707. \n\nAs x goes down from 0.5 to 0, we are taking **higher** roots. So the cube root (^3 √) **we need the number multiplied 3 times** to get 0.333333 (or 1/3) : which is ~0.693\n\nWe can intuit that we need smaller inputs (0.707 to 0.693) to get smaller outputs from 0.5 to 0.3, but *why does this number go back up as x gets to 0?* \n\nThe way I think about this, as we approach 0, we're taking a very high root, **so we the number multiplied many times**. So even if we only need an output of 0.1, **we need the number multiplied 10 times with itself**, which is ~0.794\n\n\nWhy the bottom of this function ends up at the ~0.3678? I don't know if there is a **why** answer, that's why it's a constant! \n\n[Euler's number/constant](_URL_2_)!\n\nLet's look at a [fun graph from Wolfram|Alpha](_URL_1_) (great tool if you don't want to pull up excel all the time).\n\nAs we can see the minimum is at 1/e",
"The minimum occurs at 1/e, where e is [Euler's number](_URL_3_). This number crops up a lot in math.\n\nSo, we know that x^0 = 1 and x^1 = x. So if we're computing x^x in the range of 0 to 1, we have our end points. Moreover, we know that, as you move the exponent closer to 0, the result gets closer to 1, and if you move the exponent closer to 1, the result gets closer to x.\n\nNow find x^x for anything in between. If it's equal to 1, then all values in between are likely equal to 1. If it's less, then you have a local minimum somewhere. If it's more, you have a local maximum somewhere. Nothing special about it.",
"Simplest answer: Type x ^ x in Google and you'll see that it dips between 0 and 1. The point at which it hits its minimum is e^(-1) ≈ 0.36787944117.\n\nELI20 version: If you look at the derivative(which basically tells you the slope of a function at a given point), it's x^x (ln x + 1). x^x is positive for sure if x > 0.\n\nln x + 1 is negative if 0 < x < e^(-1). It becomes positive if x > e^(-1).\n\nBut the derivative will be negative (since it's a positive * a negative) if 0 < x < e^(-1). e^(-1) is where the value of the original function will hit the minimum. Past that, the derivative is positive.\n\nedit: fixed, thanks /u/breezehair"
] |
How do soccer players curve the parabolic trajectory of the soccer sphere? | [
"A ball only follows a parabolic trajectory in the absence of air resistance.\n\nA spinning ball deflects airflow around the ball, which creates a force on the ball. This is called the [Magnus effect](_URL_0_).",
"spin on a ball causes a slight difference in pressure which will create a lift force. its the same principle as the lift on an aeroplane wing, except in the case of a wing the pressure difference is created by different surface lengths on the top and bottom of the wing. say a tennis player hits a ground stroke with top spin, the ball is travelling along its trajectory towards the other side of the court but it is also rotating towards the opposing player and down. because the top surface of the ball is rotating \"forward\" and the bottom surface is rotating \"backward\", the top surface is generating more air resistance, creates a high pressure zone compared to the bottom and a force is applied to the ball moving from high to low pressure, that is the force is applied on the ball in a downwards direction because of the high pressure air flow on top of the ball, and the ball drops to the ground faster than it would with no spin or backspin\n\ne: the concept is the same in soccer, except the axis of rotation of the ball is perpendicular to the topspin example, and the force generated is also perpendicular",
"Kicking the center of a ball and rotate it by going from center to left/right of the ball with the side of your foot. Causing the ball to rotate.\n\nkick the ball a little beneath the center so it can go up in the air.",
"Spin. Kick left or right side of ball, like you can do with a pool ball and cue.",
"I don't know the math, but two things to bring to light\n\n1. When the ball is kicked, it is no longer a sphere. That is why a flatter ball will bend more.\n\n2. When the ball spins, one side of the ball will have less friction against win and cause it to move slightly faster creating a bend.\n\nIt is hard to explain without using visual representation. If you want to see some explanation and the craziest goal ever, watch [this](_URL_1_)",
"Spin. Like a curveball in baseball, spin will change how the air flows over the ball. Irregular airflow then causes the path of the ball to change, usually in a smooth curve.",
"Are you asking how the players spin the ball? Or why the trajectory will curve when the ball is spinning?"
] |
Why are dreams so crazy & random? | [
"While you are awake, your brain constructs an understanding of what's going on around you with continuous correction and revision based on information from your senses. \n\nWhile you are asleep, your brain constructs an understanding of what's going on around you with almost no correction or revision based on your senses, and so it goes strange."
] |
Why does vanilla extract taste amazing when paired with some foods , but tastes horrible alone? | [
"Pure vanilla extract is made from soaking vanilla beans in vodka or other strong clear alcohol, which is why it doesn't taste as good without any sweet flavoring to go with it.",
"Some vanilla flavoring is made from a beaver's anal glands, check it out.\n\n_URL_0_",
"Vanilla extract is a concentrate of sorts, and an alcohol (which is why too much can ruin the texture of whipped cream). When you add it to cookies or coke, it is heavily diluted, and tastes much better.",
"Concentration. It needs space to breathe and taste palatable; ie. diluted and mixed into a large measure of other food - cake, ice cream, whatever. Same goes for hard liquor, bitters, and other alcohol-based concoctions - they need to be diluted, usually with water, before their aromas and flavors can come to the fore while their harshness fades. (When I say \"hard liquor\", I mean the distilled essence before it gets bottled.) This is why a given recipe will only call for, say, a half-teaspoon of vanilla extract - it's so concentrated that that's all you need.\n\nSource: Whatever, I'm just guessing here. But I do cook for a living.\n\nOh, a recipe: Vanilla sugar. Buy a couple of vanilla pods (they're not cheap), cut them into 2-inch or so lengths, then cut each of these pieces lengthwise to \"open up\" the pod. Place these in a jar filled with plain white sugar. Voila. The seeds and pods of the vanilla infuse the sugar with flavor. Great in coffee, and that jar will last for months (probably years). Just keep topping it up with sugar as needed.",
"Not a cool recipe, but a cool product is the Nielsen Massey vanilla bean paste. There is just something about seeing the tiny flecks of vanilla bean that makes everything taste so much better. It's also MUCH MUCH cheaper than buying vanilla bean pods and doing it yourself. The flavor is so much more intense and rich."
] |
Why do male orgasms get more intense in relatively short amounts of succession? | [
"Well everyone is different. Wildly so, in fact. Some people are capable of sustaining multiple, repeating orgasms of increasing intensity. This is more common in women, but certainly possible in men. Others can only have one orgasm of great intensity, after which they lose sexual stimulation for a long refractory period. \n\nWhat you experience is relatively rare compared to the general male population. But the reason they escalate in intensity is probanly because none of these are \"true\" orgasms that kick off a refractory period. Theyre more like partial orgasms that heighten sexual stimulation and pleasure, so the orgasms continue to build in pleasure until the satiation signal is triggered.",
"It's a set of chemical responses within the nervous system that trigger other physiological responses. Generally, those regions responsible for chemical signals become more active and able to do so.\n\nA good analogy for this might be working out your muscles. As you do some warmup exercises, you're actually able to lift more weight than at the beginning of a workout. Then you get tired.\n\nOf course there is a refractory period for reserves of the transmitters in those regions to build back up, among other things, much like seeing a bright light depletes the chemicals in your retinas so you have to wait until you can see again.\n\nTo go back to the muscle analogy, this would be hitting a hard set of reps until you can't lift the weight anymore. In the short term, the chemicals are depleted, but the muscles are getting extra blood and signals now so the strength increases. Lather, rinse, repeat. No wait, don't lather... everyone knows soap is a bad idea here..."
] |
What were the Roaring Twenties and why did it happen? | [
"OH! I'm studying this in my history class right now! But I have a \"B\" average thus far, so pardon me if I get some things wrong. \n \ntldr: Affluent young men and women were partying because it was a period after wartime. They just wanted to live life, ya know. They bucked societal norms such as dressing conservatively and marrying early. Working class Americans had more leisure time and a little more spending money due to the progressive era reforms for better pay, safer working environments, etc.\n \nEssentially: the roaring twenties was a period where the reforms of the previous progressive era (1890s-1920s) were taking effect. Workers were able to form unions, an 8 hour workday (and 5-6 day workweek) was put into effect, minimum wage was introduced, safer work environment, etc. The everyday worker had slightly more leisure time and more spending money. They also had a greater choice in entertainment: professional sports were just getting started, movies just got sound, etc. \n \nThere was also as overrepresented minority of Americans called \"flappers\", mainly affluent white folks. They were mostly young men and women who bucked the trend of traditional fashion and lifestyle. The women wore skirts and dresses above their ankles and cut their hair shorter. Showing ankle was considered risqué. The men wore suits and hats. Simple hats back then were considered poor mans attire, so for a well-to-do male to be wearing one was a statement. These young men and women had just come out of wartime and wanted to take things easy. They married later, had kids later in life, \"love marriages\" became more popular than arranged marriages, they danced and listened to \"black peoples' music (jazz)\". A few aspects of the flapper lifestyle (eg: new fashion trends) trickled down to working class Americans. \n \nThe Harlem Renaissance also took shape. There was a \"Great Migration\" of African-Americans from the South to the North. Mostly because transportation became cheaper. Many African-Americans migrated to the same neighborhoods. The prominent cities were Chicago, St. Louis, New York City, and Philadelphia. African-American culture was born: soul food, jazz (Louis Armstrong), poetry (Langston Hughes, Richard Wright), and even sports (Jackie Robinson).\n\nThe civil rights movement progressed. I can't speak much to the African-American rights movement but I do know that women's suffrage was just coming to a close. The 19th Amendment (cannot discriminate based on sex) was added in 1920.",
"Post WWI America experienced economic growth fueled, mostly, by stock market speculation. The relief of a war being over coupled with economic prosperity resulted in essentially nine years of partying. (1920-1929). Drinks flowed as Prohibition was a few years in the future, organized crime flourished on all the vice and many law enforcement agencies were in cahoots with them. It was a great period for music, the rapid growth of radio, the big bands and the cinema. For whatever reason the censors allowed a lot of salacious, for the time, content. \n\nThe music ended with the stock market crash of 1929."
] |
Why is there no standard for which side the gas tank is on on a car? | [
"For the most part, the gas tank is centered on the frame. What you're probably thinking of is where the gas cap is, which generally will depend on the manufacturer. U/aykprod [answered that one](_URL_0_).",
"Don't know the answer to that, but want to add a little life tip regarding finding which side it is on.\nCan't speak for everycar here but most modern cars in Australia will have a little arrow on either side of the fuel pump symbol on the gauge. This little arrow will be pointing to the side that the cap is on.",
"There are really two reasons for having caps on varying sides of the car. The first is that it allows petrol stations to have dispensers on both sides, which allows them to fit more pumps into a given area and means you can fill up faster.\n\nThe other is really just comes down to the manufacturer. There is no cost saving in either side, as some people have suggested here. Cars are generally designed so that when the car is parked, the fuel cap is facing the kerb. As cars are manufactured for a range of countries which drive on varying sides of the road, the manufacturer will judge the cars main market and place the cap accordingly.\n\nSource: worked for a car company",
"This is not an answer to your questions, rather what I think is an interesting tidbit.\n\nIf you ever have trouble remembering which side the gas tank nozzle is on the car, just look at the fuel gauge, it will usually have a gas pump symbol with a hose on it. If the hose is on the right, that means the tank is on the right of the car and vice verse.",
"Vehicle standards are usually reserved for safety and environmental concerns -- There's no reason why there couldn't be, but why add one extra thing that manufacturers HAVE to do? All it does is increase cost.",
"I don't think you're going to get any satisfying answer as to why they couldn't all be on the same side. It would make easier if they were."
] |
How do airport scans actually work? | [
"Congratulations on making it onto a watch list! Without saying anything too classified, density. Density of materials is almost like a finger print.",
"The new full-body scanners use millimeter-wave radiation to detect items based on their density. Anything that is more dense than the surrounding matter will show up on the image. \n\nThere is some controversy about the health impacts of these machines, especially for frequent flyers."
] |
Why are Rolex watches considered to be so valuable? | [
"For starters, they're made with expensive and valuable materials like jeweled movements, sapphire glass, and gold. Second, the movements are mostly mechanical, requiring great skill, engineering time, and delicate manufacture.\n\nThird and most importantly, Rolexes are valuable because **people think they are**. If tomorrow we woke up with the idea that a Rolex could never be worth more than $500, that's what they would be worth.\n\nRolex is an \"aspirational brand\" meaning that **people use it** as a mark of proof that they've achieved a certain level of status, wealth, or power. If people no longer considered it a mark of achievement, it would tank in value.",
"Also keep in mind that Rolex watches are incredibly high quality. They were pretty much unknown (at least compared to the degree of fame they’ve achieved today) until someone swam the English Channel while wearing one and it still worked.",
"In addition to all these, their biggest sellers are their stainless steel sport watches and they limit production to keep secondary market prices high. For a while (and maybe still) a SS Daytona was worth thousands more on the secondary market than it cost from a authorized dealer. Also in many instances, dealers hold back the prized SS models for their best customers so the only chance to get one when they come out is to have spent tens of thousands of dollars on other rolex models in the past. They also hold value reasonably well unlike cars or other goods or even other watches. Say you buy a list price $3000 tag heuer dive aquaracer. If you sold it on the secondary market it might only get $1000 or so. A rolex submariner thats 8000 is probably still going to go for 7000 to 7500 with box and papers even used.",
"In the world of Horology, Rolex is the poor mans expensive watch. If you want proper expensive wrist watches, you have to look at; Patek Philippe, Philippe Dufour, Kari Voutilainen, Romain Gauthier. The \"cheap\" ones will cost more than your average home. \n\nThe masses think Rolex is the end game in nice/expensive watches, because they do a good job in promoting themselves, specially around posh sports. \n\nMoney talks, but wealth whispers."
] |
How can you be sure that it is safe to give your credit card number to customer service online or over the phone? | [
"As someone who used to do this for a living - you can never be 100% sure, but that doesn't mean the companies don't have a load of policies in place to minimize the danger. Company I used to work for, we weren't allowed to read back the number (so nobody that is passing can copy it), everything got recorded, we had a certain kind of criminal background check to even work there etc. Does that mean that someone couldn't steal those credit card numbers? No. Someone who is very motivated could probably still do it, but the policies *do* minimize the danger and they also usually set up things in such a way that if you credit card number is stolen, they will have a good chance of finding out who did it."
] |
Why do I find things funnier when I'm tired? | [
"Same reason you find everything funnier when you're drunk- impaired judgement.",
"We call that \"slap happy\" in my family. I distinctly remember when I was about 7, my grandmother and I staying up far too late and someone made a rhyme on accident and it just spiralled out of control until we were giggling hysterically.",
"I may be just guessing at what impaired judgement means here, but my theory is that your brain just makes lesser checks while tired/drunk. So it doesn't do a pass of \"Do I look silly? Is laughing right now inappropriate? Is this even really funny? Am I better than this? Is anyone else laughing with me?\" etc. It just... laughs."
] |
Why is Tony Abbott (Prime Minister of Australia) so hated? | [
"Where to start?\n\nHe attacked the previous Prime Minister for being too controlling of his MPs. One of the first things Abbott did when he became PM was to order his MPs to not speak to the media without running it past him first.\n\nHe attacked the previous government for not being transparent enough. One of the other things he did upon becoming PM was stop government information being given to the public. This is information that was just automatically available to the public. Want to know how much money the government is spending? TOO BAD! Want to know how many \"illegal\" boats have arrived? TOO BAD!\n\nHe attacked the previous government over how much money it was spending. Upon becoming PM he increased government spending and raised the debt ceiling by something like $200 billion. \n\nHe wants to get rid of this thinking in schools and go back to the good ol' days where the teacher taught you something and to pass you needed to give the one and only correct answer. Critical thinking is for commies!\n\nHe massively cut science funding and described most of science as being crap.\n\nWhile in opposition he said that politicians and governments shouldn't be afraid of the media (probably because they were actively trying to get him elected). Now that the ABC isn't painting a rosy picture of his government he's stated that the ABC is unAustralian and unpatriotic and he's announced funding cuts to the ABC.\n\nThe list goes on and on and on and on.\n\nEdit - Here's a good one. He claimed, after being attacked by the public and the media for being anti gay, that he doesn't oppose same sex marriage, he just doesn't think it's a priority in today's economic climate (yes, rights aren't important unless Abbott thinks the economy is doing well). The Australian Capital Territory passed a bill allowing same sex marriage. Remember, Abbott claimed he wasn't against it. Anyway, when the bill was passed Abbott ran as fast as he could to the High Court of Australia to get them to overturn the bill."
] |
How and Why does the DEA keep marijuana as a schedule 1 drug? | [
"A little personal view, perhaps not the most informed:\n\nWhat I know is that marijuana has been legally considered that way because it's considered to be a \"gateway drug\" toward more damaging ones.\n\nHowever, in my opinion, the very reason why it's a gateway drug is because it's prosecuted the same way the other schedule 1 drugs are. In that a marijuana dealer has absolutely no reason to *only* sell marijuana since they get pretty much the same sentence if caught, whether they sell marijuana only, or if they sell it along with heroin and other harmful substances. And obviously they will push their more expensive wares onto buyers because they want to sell that as well.\n\nI think that at least lowering the severity class of marijuana would mostly eliminate this problem.\n\nI mean, objectively, it's utterly ridiculous to have it in the same schedule (marijuana) as freaking heroin. But it just gives marijuana dealers a reason to also deal heroin.",
"Simple: Money. \n\nMarijuana is the most highly used schedule 1 drug, so many DEA resources are dedicated to it. Without it as a schedule 1 drug, the majority of the work they do would not be necessary and their funding would be cut. Nobody would make a decision that would lead to their own funding being cut.",
"A very good answer for this comes from the fight over MDMA.\n\nIn June 1984, [the Multidisciplinary Association for Psychedelic Studies](_URL_0_) brought suit against the DEA's attempt to reschedule MDMA as a Schedule I drug because they had a ton of evidence showing that MDMA was useful as a therapeutic adjunct. \n > “There were hundreds of psychiatrists and psychotherapists that were using it informally, and they were using it for all sorts of things in private settings,” Rick Doblin (founder of MAPS) tells Inverse. “It was being used for PTSD, it was being used for couples’ therapy, it was being used for personal growth, it was being used for spirituality.”\n*...and MAPS won.*\nThe administrative law judge recommended MDMA be scheduled as a Schedule III drug based on low risk of abuse against a high therapeutic benefit. \n\nThe DEA **completely ignored the decision** and made MDMA Schedule I anyways. Despite MAPS pursuing further court action - and winning - DEA gave MAPS the finger. \n\nThe lesson? DEA don't give a **CENSORED BECAUSE FIVE YEAR OLDS** about the science, about the evidence, or even what courts will tell them to do most of the time. \n\nDEA tends to only loosen its grip if a new law tells them to or if an executive order tells them to. Otherwise, they constantly seek out new substances to schedule. \n\n[Source](_URL_1_)",
"In short, the Federal government is run more by politics than by science.\n\nThe Nixon administration decided to forcefully attack marijuana users when they determined that (at least in the early 1970s) this substance was more popular among black people, poor people, and Democrats. So they got the government to spend billions of dollars and many years of work to try to persuade people of the evil of this substance and of those who use it."
] |
How does Imodium work? | [
"They decrease the water absorption in the (mostly small) intestine. A lot of water and nutrients are absorbed by the intestines, and Imodium (in laxatives) basically reduces the absorption of the water. That's also why they're so dangerous if taken in a large dosis."
] |
why there seems to be no patent war in the car industry. | [
"General Motors [patented electric car batteries and never used them](_URL_0_), so their competition couldn't either.\n\nI think this is even worse than patent warring."
] |
If the U.S. president is commander of the military, why isn't his/her experience in military tactics and strategy ever a talking point? | [
"Because we don't expect the President to be an expert in military tactics any more than we expect him to be an expert in medicine or prison construction or chemistry or meteorology or agricultural science or any of the other things that the President is ultimately responsible for,\n\nWhat we need out of our leaders is leadership -- not nerd-like knowledge of a narrow area of focus. We need someone who can get and listen to people who *are* experts in these areas and make the appropriate decisions.",
"There have been exceptions in US history, but generally a country is better off when the leader of a country is not also a member of the military, or an expert in military theory. Those types of leaders tend to treat non-military issues the same way.\n\nDictatorial, top-down leadership. A civilian leader has better odds of being a good leader for a country.",
"The most important thing they could add would be a combination of two traits:\n\n1. How well they can articulate their principles and values when making a decision, and more importantly into defining a clear mission. Stopping ISIS isnt a sufficiently clear mission for the military. But saying instead \"we will use a coordinated allied bombing campaign to attrit ISIS ranks focusing on mid level leadership and restrict their ability to coordinate and move large forces freely\" is much more clear and achievable. \n\n2. How well they can listen to men and women who have made the profession of war their careers and are the best their is at the task..\n\nA President has no need, and would only hurt (see Nixon or LBJ hand selecting bombing targets with McNamara in Vietnam) when they get too involved. It doesnt help the conduct of a war for the President to best know where to employ an armored division, or how to prioritize targets for air strikes.\n\n\nThe President needs instead to be able to articulate a clear, achievable, goal for any application of force. and to make his values and decisions when presented with choices as clear as possible.",
"It has been. Bush's lack of military experience was used against him when he ran against Kerry (it backfired), and Clinton's was an issue against both Bush Sr. and Dole.\n\nIt has become less of an issue because fewer presidential candidates have served in the military, and those that did weren't in leadership positions. John McCain was a war hero, and he has a great emotional understanding of war, but never make strategic decisions, he flew an airplane.\n\nAnd considering that every presidential election has a few hundred congressmen and governors also running for office, highlighting one guy's experience might hurt everyone else.",
"The president does not need to be an expert on anything but leading people. He forms a cabinet of advisers, including several who are experts in military tactics who fill in all knowledge gaps he may have.",
"If there's a difference in service between the two candidates, it definitely is a talking point. It was brought up a lot in 2008 between Obama and McCain - Obama's lack of experience was hammered by Republicans, and McCain's service, time as a POW, and military congressional committee service were used as an argument in his favor - but the economy ended up overwhelming everything else.\n\nBut very few presidential candidates have actual experience in devising broad military strategy, unless they've been career military folks who switched over to politics later in life, which is relatively rare (Eisenhower is an exception). It's expected that they'll lean heavily on military leaders for tactical advice."
] |
Why aren't beers required by law to have nutritional info on their label? | [
"Foods are regulated by the FDA. The FDA requires nutritional labeling on foods.\n\nBeer is regulated by the BATFE. The BATFE does not require nutritional labeling on beer - in fact, doesn't want it, because it would give the impression that beer is food.",
"In part because the ingredients that went into it aren't what's in the bottle. That's because the part people make is the sweet wort, which is then fed to yeast. The yeast eat the sugars and interact with the ingredients in ways that make a list of \"original\" ingredients misleading. You can put an extra 5 pound bag of sugar into a beer and the yeast will eat ALL of it and make alcohol/carbon dioxide. If you put that sugar on the label (after all, it went into the kettle), the carb counts would be insane. And wrong.\n\nThis actually comes up in many articles about carbs/beer/diabetes. Articles talk about how much maltose (sugar from the grain) is in beer, completely ignoring the fact that nearly all of that maltose was where the alcohol and bubbles came from."
] |
November day light savings time | [
"You definitely gain the extra hour. Give him an example. Say you forget to change your clock the previous night. You wake up at 6, realize it's daylight savings, set the clock back to 5, then sleep until 6... again.",
"We set the clocks back an hour to gain an hour, saving an hour of daylight because the sun begins to set earlier later in the year. This was thought of a long long time ago, before electricity was a thing so that people could continue to work with that \"extra\" hour if light. So the day of the change, yes, we gain an hour. Then it doesn't really make a difference until savings time ends, and then we lose an hour"
] |
How Momentum is Conserved when Light Refracts | [
"When light refracts at the boundary, it also reflects. This reflected light carries momentum which then satisfies momentum conservation."
] |
Why does it make sense for an internet company to charge more money for a faster connection speed? | [
"The more traffic you want to be able to carry, the more that network will cost to build and to maintain. The equipment capital expenditure is a lot of it, but service contracts and transit opex is also more.\n\nAs an example, you can get an old switch with 1 gbps interfaces for next to nothing. Getting a new one with 100 gbps interfaces is going to cost orders of magnitude more.",
"On the internet, you data is broken up into tiny pieces called \"packets\". Each packet can take its own pathway through the internet. One way to increase speed is to send lots of packets at the same time. To send more packets at the same time, the ISP needs equipment that can handle that. That costs money. ISP's are businesses so anything they do that costs money is either paid for by the customers or by getting a loan from somewhere, but even then they pay back the loan with money from customers.\n\nThey could just charge *everyone* more money for the new equipment, but instead, some ISP choose to put more of the cost burden on the customers that are using the most data. \n\nThis is what they use as a justification. Many people don't believe it to be true.",
"Because they can make more money.\n\nLike every company, they do analysis on what the most profitable prices they can sell their goods and services for and price their products at the most profitable prices\n\nNothing else matters, its just business, ISPs are just a business like the corner store down the street, an airline, or whatever.\n\nIts a financial/economic decision.",
"I work in telecommunications though I don’t know much about the hardware, but it seems to me that you can only send/ receive so much data down the pipe. So those who pay more get a larger percentage of the pipe for their data. \n\nAlso, those who are willing to pay more for faster service are in a way funding the construction of bigger pipes and showing their demand for it.",
"All businesses charge the maximum amount they can get away with charging. So if they can convince customers to accept paying more they will do it."
] |
How do investors who invest into apps like snapchat make their money back? | [
"This is a bit long to explain, but I'll try to keep it as simple as possible.\n\nImagine Snapchat as a bigass pie. An investor will buy up a percentage of that pie. As Snapchat grows, each piece of its pie will grow and become more valuable. However, the investor still owns the same percentage of the pie.\n\nSo, because each piece is worth more, that means he's made a profit, right? Not yet - on paper, he has. To actually make (or \"realize\") a profit, he has to sell his percentage/piece (called a \"stake\"). In the business world, investors have three options for selling their piece of pie and receiving cash:\n\n1-Sell to another investor. The investor may contact an investment bank to find another pie eater, or may have a friend looking to buy a piece. Once he sells his piece and receives cash in exchange, he has made or \"realized\" his profit.\n\nNow, if an investor thinks the Snapchat pie could grow even more, he may want to hold on to part of his piece. He doesn't have to sell the whole thing.\n\n2-He can \"cash out\" or sell his piece back to Snapchat. To understand this, you have to understand what Equity in a company is.\n\nAll of the things a company owns (cash/equipment/inventory/supplies/property/intangibles) are called \"assets\". To get these assets, a company needs to borrow money (\"liabilities\") or sell a stake in the company (\"equity\"). Using cash, a company has to pay back what it borrows before paying owners. This means that equity can be thought of as the assets owners have a claim to once all debts are paid.\n\nSo, when cashing out, an investor will sell his piece/stake of the pie (\"equity\" in Snapchat) back to Snap corporate, and receive cash (an \"asset\" of Snapchat) in return. Snapchat may favor this if they think the company will continue to grow, and can take on debt or sell pieces to more people (see option 3) - the more of the pie that Snap itself sells, the more cash the company receives. So, it may want to own more of its own pie.\n\n3-Initial Public Offering (IPO) - if there is enough interest, Snapchat and its investors will split their pieces into even smaller slices (called \"shares\") and offer them to individual investors on the open market. Now, if Snap sells some of its shares, it will receive the cash. But, if an investor sells shares from his piece, he gets to keep the cash.\n\nLet me know if this is clear enough, or if you have any other questions. Hope this helps! \n\nEdit: formatting, on mobile and can't preview"
] |
Why is ice cream soft when it's first opened but harden after you put in back in the freezer? | [
"When ice cream is made it's constantly churned while being frozen, the churning process breaks up the ice crystals into small pieces making the ice cream soft, when you put partially melted ice cream in the freezer there is no churning so large ice crystals develop leaving you with hard ice cream."
] |
Why does my barber hand me a warm wet towel when he finishes cutting my hair? | [
"I would assume so you can wipe the stray hairs off your face and neck? My barber just blasts me in the face with a hair dryer."
] |
why is the square root of -100 an odd equasion? | [
"The square root of 100 is 10.\n\nThere is no \"real\" square root of a negative number, because ~~no two numbers multiplied together~~ *no number multiplied by itself* can make a negative number. So we invented an \"imaginary\" number called i to represent the square root of -1. So the square root of -100 is 10 * i, also written as 10i. In other words, 10, but imaginary.",
"Mathematicians like to take \"you can't do that\" as a challenge. Therefore, when you have an equation such as *x*^2 = -100, which has \"no solutions\", we make up new numbers! Imaginary numbers are what you get when you multiply real numbers (that is, any number you could think of: positive or negative, integer or fraction, rational or irrational) by the \"imaginary unit\", which we call *i* (or if you're an engineer, *j*). This *i* is just defined to be a \"number\" that, when squared, yields -1.\n\nIt's a strange concept, because you couldn't imagine 3*i* apples; you can't say whether 5.4*i* is bigger or smaller than 7. Instead, imagine the imaginary numbers on a number line perpendicular to the real number line, like a *y* axis. This is called the Argand diagram.\n\nBut because it's a \"number\", we can do numbery things to them. For example, we can add them: 3*i* + 5*i* = 8*i*. Or we can multiply them: 3*i* × 4*i* = 12*i*^2 = 12 × -1 = -12.\n\nWe can even add real and imaginary numbers together, to create complex numbers, such as 3+4*i*.\n\nOne of the nice things about the set of complex numbers is that it's \"algebraically complete\". That means polynomial equations, which look like *x*^2 - 3*x* + 3 = 0, or *x*^3 + 2*x* = 0 always have as many solutions as the biggest power in the equation (2 and 3 respectively in this case).\n\nComplex numbers are very useful in physics and engineering for describing the behaviour of waves, and in general in maths for anything that rotates. That's because multiplying by *i* corresponds to rotating around the Argand diagram by a quarter-turn anti-clockwise.",
"If you multiple any number by itself, the answer will be a positive number. So, 10 times 10 is 100, and -10 times -10 is 100 as well. So, how do you find the square root of a negative number? You need new numbers which don't seem to exist. That's where imaginary numbers come in. So the square root of -100 really is imaginary 10. I'm not sure what the joke is, but I hope that explains it.\n\n\nIf you want explanation as to the further importance of imaginary numbers, you'll have to ask someone more knowledgeable than myself.",
"I think the joke you are referring to is something like this:\n\n\"My girlfriend is like the square root of -100: a perfect 10, but also imaginary.\""
] |
How does Youtube channels like "WatchMojo" earn money when all their videos contain copyrighted materials? | [
"Youtuber here. Watchmojo is their own youtube Network. When you join a network, you are assigned a custom id under your youtube network. The ID number is what youtube references. As long as your content falls under the approved media for that ID number, you can monetize.\n\nIf Watchmojo has these various forms of media covered under their custom id, which they probably do since a majority of films, tv programs and so on are owned by a handful of massive companies, they monetize their videos. This is the same reason Cinemasins can monetize their content.\n\nEdit: Clarification",
"The give credit on each scene they show , for example ( The Wolverine(2013)20th century fox)",
"There are certain exceptions that can be made to copyright law, including but not limited to: \n\nParody or critique of work, which allows people such as cinemasins to use clips and still monetize.\n\nArchival reproduction of broadcasts, which is why taping shows wasn't illegal.\n\n'Personal study', meaning you can't be put in jail for photocopying a textbook or taking a picture of a coke ad etc.\n\nThere are others. The general rule for copyright law is that it is designed so no-one can steal content, and people receive far compensation when their work is used but so that tinkering and further creativity is still permitted. In reality it doesn't always work out that way though.\n\n[Source](_URL_0_)",
"They explain this very question in an episode of their show: [WMFAQ Ep. 15](_URL_1_)"
] |
Why are bitter citrus fruit harder to peel? | [
"The bitter ones we humans haven't cultivated into tasty fruits that are easy to eat.\n\nThe closer to natural you go, the less sweet and harder to peel citrus get.",
"Genetic patterns suggest the four original parents of the citrus varieties we have today are citron, pummelo, mandarin, and papeda. Generally the sweeter varieties you'd be familiar with like oranges and clementines have more mandarin parentage, grapefruits have more pummelo parentage, and lemons have more citron parentage. \n\nFrom \n_URL_0_:\n\n > \"...mandarins are therefore all the more important as the **only sweet fruit** among the parental species.\"\n\nMandarins happened to have thinner skin which means easier peeling, and selective breeding amplified this.",
"This is not necessarily the case. The kumquat is an extremely bitter citrus fruit, yet it is not all that difficult to peel.\n\n**Edit:** Ironically, the rind itself is actually sweeter than the fruit.",
"One might think it's part of the same evolution that has them be sour -- so creatures don't eat them.\n\nReally, it's probably more just because they were bred (remember, most of what we eat has been genetically cultivated over thousands of years) with certain traits that were beneficial, and the thicker peel was not a significant detriment."
] |
How do lottery ticket companies make sure their workers don't track down the winning tickets that they print? | [
"A computer prints the numbers on the scratchoff tickets as they roll through the printing presses at a thousand tickets a minute and the machine also coats the tickets with the scratch off coating in the same process. So when they come out of the press all the employee sees is the completed tickets in a giant stack. They have no way of knowing which tickets are winners unless they are upper management of the company who program the software. Those employees are heavily scrutinized at all times to make sure there is no way they can cheat the system."
] |
Why do astronomers look for planets that could possibly support life when it is technically impossible to transfer the population into it? And even traveling would take many, many years. | [
"Many years ago going to the moon seemed Imposible, Negativity ain't gonna bring ya nowhere bruh",
"If it can sustain life, perhaps it has life. It's a planetary life roulette of sorts in hopes of finding others to share/learn with/from.",
"People in general, not just astronomers, always want to explore the unexplored. And seeing how we humans have explored mostly every nook and cranny of our planet Earth, all we have left to do is look up and explore outwards. Not only that, but the idea of not knowing if we are truly alone in the universe is one of, if not the, most important question asked right after \"why do things fall down and not up?\" or \"what is over that mountain?\"\n So even if one day we do find life and its thousands of light years away, just knowing that we are not alone is one step closer to understand where we are and how we fit as a species in the universe.",
"Because the goal isn't simply to find a planet to transfer humans onto it. Imagine the scientific opportunities of finding a planet with confirmed life on it. The experience and new knowledge we could gain from that. It doesn't matter that humans will likely never set foot on that planet. Knowledge itself is the goal.",
"They're scientist. They have all have a thirst for knowledge but let's not assume they all work to save or perserve humanity."
] |
why do some animals like cats give birth to multiple offspring but humans usually only have one baby per pregnancy? | [
"Place on the food chain. Prey animals will have more offspring to account for losses from predators. Imagine a grizzly bear having 10 cubs a few times a year."
] |
How can youtubers post videos of them singing popular songs without getting their videos taken down, but I can't upload a school video that has "Eat it" (which was published in 1984)? | [
"> I thought that the copyright laws protected people from singing songs from within the last 20 years?\n\nThat's patent law (which only applies to inventions, product designs and manufacturing processes).\n\nCopyright typically lasts for the entirety of the author's life plus an additional 50-75 years depending on what jurisdiction you live in.\n\nWhen people post themselves singing popular songs on Youtube and it's not taken down, it's usually because the use of that particular song is covered by blanket licensing arrangements Youtube has with record labels, music publishers, and performing rights agencies. \n\nMusic which they haven't licensed in this way and/or which the publisher has specifically asked Youtube to take down (e.g. through YT's content matching system) will be removed shortly after being uploaded."
] |
Why do sounds go deeper when slowed down & higher pitched when sped up? | [
"Sound is a wave and pitch is caused by distance between the compressions (crests) of the wave. A shorter distance means a higher pitch. It's not so much causation as definition. Simple sound editing software only compresses the waveform when speeding up, pushing compressions together, resulting in higher pitch. This is done so that the sound lasts a shorter time, hence is sped up. Better software also reduces the number of compressions so that pitch remains the same. Like a multiply by x followed by divide by x."
] |
Are facial expressions natural or a construct of our society? | [
"[Studies show](_URL_0_) certain facial expressions are universal.\n\nA study of blind people has shown that \"anger, contempt, disgust, sadness, surprise and multiple types of smiles\" were consistent across the seeing and non-seeing.",
"Most facial expressions (the ones for basic emotions like joy, anger, sadness, disgust) are universal and the same across all of humanity. They're from deep in our history, long before language or even really culture.\n\nThere are slightly cultural differences, but they are pretty minor. For example, everyone smiles and laughs when happy, but some cultures laugh loudly and others tend to laugh more demurely.",
"Theyre natural. People who are blind from birth still smile.",
"I'm happy someone asked about one of my favorite subjects.\n\nELI5: in the same way you never have to learn that when something tickles you squirm or when you need to pee you go to the toilet, you never have to learn that you smile when you are happy.. All people around the world are born with all the facial expressions that are triggered by emotions, but others can be learned (nodding is yes in some cultures and no in others). Someone from USA will express emotions through the same facial expressions as someone from France, China, Russia, or even totally isolated tribes in Amazonas.\n\n\nFacial expressions are nature, not nurture. Human beings all across the world all express emotions through the same facial expressions without ever being learned how to do it, and it is unconsciously triggered. Some facial expressions, such as smiling, is even almost impossible to fake and can only be triggered by emotions.\n\nIf you more curious about the subject I suggest you pick up Emotions Revealed by Paul Ekman or any of his other books. \n\nFeel free to ask questions if you have any",
"They are results of our biology. Both physiologically and because of muscular structure, a smile is a smile."
] |
How does difference in air pressure affect cloud formation? | [
"What exactly do you mean by \"differences in pressure\"?\n\nDifferences in pressure cause wind... and the wind can indirectly affect cloud formation.\n\nHowever, the main factors in cloud formation are differences in temperature at different altitudes, terrain (such as mountains), and weather fronts (where different air masses come together, and those air masses typically have different temperatures)."
] |
- how do engineer come up with names for different parts? | [
"Engineering names for parts are usually descriptive of the design or function of a part. Thus an \"oil filter\" filters the oil in a car.\n\nPerhaps if you had an interesting example you could get an interesting explanation."
] |
What it takes for a Third World city to achieve good governance and a high quality of life for its residents ? | [
"There is an entire academic discipline devoted to this question. If anyone had a definitive, ELI5-able answer for it, they'd probably have a Nobel prize coming."
] |
Why does it make a difference in taste, if the water I brew tea with has boiled or not? | [
"It's about temperature and solubility. Coffee is the same way, you're toeing a fine line with certain flavor compounds that come out at certain temps.\n\nFor instance, if you boil the water, once it's all mixed in with the tea leaves it'll sit at say 204F (95C), this is hot enough to get all of the good flavors out of black tea, but in mate will draw out bitter compounds, if you use water that hasn't boiled and it's steeping at 190F (87C) then it won't be hot enough to draw all of the desired compounds out of black tea, but will be perfect for mate because it won't draw out the bitter compounds."
] |
How is betting different to buying shares? | [
"It's HUGELY different.\n\nBetting is almost always an all-or-nothing proposition that is known on a specific date and time. Either you win, or you lose at that specific time. If you win, you immediately gain currency. If you lose, you lose your currency.\n\nBuying stock is based on the hope that a specific share will gain value **over time**, not once. So you buy that share. It either gains or loses, or if you are particularly unlucky, becomes valueless. But that doesn't happen all at once, it happens over hours, days, weeks, months, or for long-term investments, years. \n\nUsually your stock has some surrender value even if it's horribly lost money. And you can hold on to it in case the company that is represented by the share does better in the long run, improving its value. But your bet has none if it loses. \n\nFinally, usually bets are (usually) not income-taxed or tax-reimbursed in the event of a loss, and can sometimes be illegal, whereas stock transactions are legal transactions that are tracked and have to be factored into your annual taxes if over a certain amount.\n\n**TL;DR: Bets are one-time all or nothing instant hopes for cash. Stocks are legal investment vehicles that gain or lose some of their value over time.",
"They are somewhat similar in the fact that there is a chance that you will either lose or gain money in both situations but that's as far as the similarities go. \n\nIn a bet you either win or lose and, in turn gain or lose a predetermined amount of money. \n\nWhen you buy a share, or \"stock\" in a company you are actually buying a very small percentage of said company. If the company does well and grows, your percentage in the company will be worth more money. If the company starts to lose money and shrinks, you're percentage will be worth less money.\n\nFor example, if you buy a .1% share in a company that is worth $200,000 it would cost you $200. \n\nNow let's say the company does well and a year later is worth $500,000. Now your .1% share in that company is worth $500 and you could sell the share for that much to turn a $300 profit.\n\nNow obviously if the company starts losing money your share would be worth less than what you paid for it."
] |
How were cartoon sound effects produced such as those from Hannah-Barbera and 80's-90's anime? | [
"They had people called \"foley artists\" who would record unique sounds. Some of these sounds would be kept in a library of sounds that could be reused, other sounds would be recorded specifically for individual purposes.\n\nThey'd use anything and everything imaginable. People still do it today, and it's not just cartoons.\n\n_URL_0_\n\nSome sounds are really obvious, like walking on concrete. Other things you have to improvise more. Like, the sound of walking on snow might not sound enough like walking on snow- sounds contradictory, but sometimes real sounds aren't as exaggerated as we'd want them to be. So maybe for walking on snow they'll instead walk on crackers, or maybe in molasses, or maybe in bread dough. Whatever sounds right.",
"Mainly from voice acting, different music instruments and what they could get (like knocking on a trashcan)"
] |
Why do i sometimes hear voices in my head when trying to sleep? | [
"Very few schizophrenics hear voices the way you describe them despite common misconceptions. So please ignore those fears.\n\nInstead you are engaging in a very common phenomena know as a pre-sleep dream or Hypnagogia. During the onset of sleep the brain fires impulses despite relaxation occurring and produces small figments of dreams. I often have vivid lucid dreams personally, but others experience a whole range of effects, from eyesight changes to even sounds and twitches.",
"Good ole reddit. Once again showing me that the whacked-out shit I go through may very well not be whacked-out after all. Or maybe it is, but at least I'm not alone.",
"This actually happens to me a lot, either with voices, gun shots, weird buzzing/pop noises (like when a guitar is unplugged), or drum noises. The drums is even more interesting because it happens only in my left ear, which is the one I keep an earbud in when I practice on an electric kit. It's like a pre-sleep FUCK YOU *rimshot* from my brain, right as I'm about to drift off.",
"exploding head syndrome, not really as exciting as it sounds, is a \"relatively undocumented parasomnia event in which the subject experiences a loud bang in their head similar to a bomb exploding, a gun going off, a clash of cymbals, ringing, or any other form of loud, indecipherable noise that seems to originate from inside the head.\" \n\nIt can also be a voice, not just a loud bang or crash."
] |
Fight Club | [
"There's this guy, we'll call him Jack. Jack isn't the happiest of men. Jack is quiet, Jack is weak, and Jack feels as though he isn't a real man. Jack feels like his life is empty and has these dark clouds over him. This depression goes so deep that it affects his mind and just when things are getting out of control, Jack meets Tyler. Tyler is very different from Jack, in all the ways he wishes he could be. Oh how Jack looks up to Tyler! This robust, dynamic, critically thinking, pinnacle of a man is everything Jack wants to be, (but not all that he seems to be). So as the two spend more time together (and even live together!), Tyler's 'words of wisdom' begin to resonate with Jack. They both feel as though people today are sheep. They buy, eat, fuck, and sleep. They adhere to lifestyle choices that mean nothing. They spend their time and money on things they don't need to appease people they don't know or care about. This angers our dynamic duo so they decide to make a change. To 'hit bottom', as Tyler would say. They begin to fight. Not to kill, not to maim, but to vent. These boys would take their frustrations and the worries and vent it out on each other in the form of frenzied fighting, bonding the members in such an intimate way that it became a life style. They breathe, eat, and sleep fight club. It becomes a religion to these men. Fuck social norms. Fuck being 'pretty'. The only time they truly felt alive was when they were beating each other to a pulp. As time progresses, the ego of Tyler swells to almost 0.5 Kanyes, and he decides that just fighting isn't enough. He wants to flip the script and make everyone wake up from this daze he believes we are all slumbering in. \n\n\n\nSo he turns Fight Club into Project Mayhem, and does this alone. Jack is devastated when he finds out he is not in on Project Mayhem. Why would Tyler do this without him? Wasn't it the two of them that started this thing? Weren't they brothers? Tyler claims that Jack isn't letting go enough and that he's not hitting bottom, and this places a wedge between the two for the first time in their relationship. Eventually, the mounted frustration between the two explodes and Tyler disappears completely. Jack then chases after him, only to find that no matter how hard he tries, he can't catch up. \n\nThis brings us to the climax of the film. Tyler finally confesses to Jack that he and Tyler are in fact the same person. Tyler manifested from the unmet desires in Jack's heart, and has begun his takeover. The ego that is Tyler starts to take control of the consciousness that is Jack, and the two clash in one final conflict to determine the dominant personality, with Jack coming out on top. He gets the girl, wins, etc. \n\nAlso alongside this is a love story between Jack and Tyler and Marla, but I'm too high and I've already written a lot and it didn't seem as pertinent to the plot. I hope this all made sense.",
"Poor guy will never get an answer from anyone who's seen it.",
"OP, can you expand what about the movie you don't understand? I'm technically am supposed to remove this thread, but it is a complex movie. What aspects of Fight Club are you confused about? Thanks.",
"If you really want to know, watch the DVD commentary. It's a satire that is critical of modern society, with a focus on consumerism, and also critical of complete rebellion against of the modern lifestyle."
] |
Why are white rats mainly used for studies instead of other rodent species? | [
"Lab rats are often of a particular strain, or a family that mice are taken from that are as genetically identical as possible. This is to be able to conduct effective studies on the effect of individual genes, and partly to limit the effect of genetic diversity in influencing the results of trials.\n\nSeveral of these strains, though not all, were derived from albino rats.",
"They are a standadized lab rat, bred for this purpose, readily available in large numbers. But actually, mice are used more.\n\n_URL_0_"
] |
Why is the Magna Carter so famous ? | [
"It is the \"Magna Carta\" and it was a document signed by the Nobles of England and was the first document to start to limit the powers of Monarchy in \"modern\" European history. It is the touchstone base for what became the British Parliamentary system and was at least in part one of the influential documents for the US constitution."
] |
Why is time considered an Illusion? | [
"Time isn't an illusion, it's a fundamental parameter of the universe. It's not a construct of human imagination it's an inherent property of the universe.",
"When people say time is an illusion, I think they mean more toward the human perception of it being constantly changing.\n\nEspecially from the perspective of a young child's perception of time vs an older person's perception. Say that young child is only 5 years old, which means 1 whole year would add 20% of time to their life, it feels like such a huge amount of time to them. Then an older person being say, 80; the same year is only about 1.25% of their whole life, it feels like it flies by because of how little of their whole life that year accounts for.\n\nThus it's the human perception of time that makes it an illusion, despite it being a fundamental property of our understanding of physics."
] |
The differences between rocks, minerals, gemstones, and crystals? | [
"**Rock** is a more generic term for any kind of hard, brittle mineral composite. Usually they're mostly silicate with some impurities and their structure varies significantly between types. Rocks have classifications and types, but usually not a specific chemical formula.\n\nA **mineral** is more specific, they are naturally occurring materials with a defined chemical makeup. Some regularly form crystals, others do not.\n\n**Gemstones** and **crystals** are highly pure minerals that have formed large orderly structures. They may or may not be transparent, depending on the mineral and purity. Usually \"gems\" are transparent mineral crystals used for jewelry purposes.\n\nTake, for example, [Iron Pyrite.](_URL_0_) It's a *mineral* with a defined chemical composition, FeS2. It can form cubic *crystals* under the right conditions, but is also present as a trace mineral in some *rocks*. It's brittle, opaque, and not terribly attractive, so it's not going to be considered a useful *gemstone*."
] |
Why do investors buy collapsing companies debts? | [
"There are quite a few reasons they do this, and a lot depends on what the bankrupt company does and why it is bankrupt. Possible scenarios include but are not limited to: \n\n\n* A company is bankrupt but still has assets that can be of value to the purchaser such as a built-in customer base, a valuable brand name, physical assets like machinery or equipment, etc. \n\n* A company purchases a bankrupt competitor so that they cannot be resurrected by someone else and then compete for marketshare in whatever business they both operate.\n\n* A cash-rich company purchases a company that has gone bankrupt due to lack of capital, and believes it can revive the company with an influx of cash.",
"The company might be dead, but its assets aren't.\n\nPatents, trademarks, copyrights, Intellectual Property, hard assets (computers, servers, etc.), not to mention the personnel.\n\nYou look at the failing company and look at the valuation of what it *does* have and pick that up for a song and a dance. The failing company takes what it can get since its on its way out anyways.\n\nThe successful company can buoy the failing company while it takes what it needs. The failing company is cleaned up, streamlined, and either placed back into service in some way, shape, or form, or is liquidated entirely for its assets and its copyrights/trademarks become a re-direct to the parent.\n\nFor example; Circuit City went to the kaput. Eventually it was bought out, and now going to _URL_0_ takes you to TigerDirect - so in the beginning, all of those circuitcity customers were now going to TigerDirect, which is a revenue increase to balance out the cost of acquiring the now dead company.\n\nValuation is a complicated game, but whenever someone spends money on < XYZ > , there is typically a good reason for it, and it almost always involves making more money down the line."
] |
Why is there controversy over the seasonal starbucks cup? | [
"Because there are no snowflakes on it and it is plain and christians think they are denouncing christmas..... Im not joking",
"Some more conservative-leaning people (particularly in the United States) feel that there's been a tendency for government, media, advertising, etc in recent decades to kind of kind of try to minimise Christmas as part of a progressive/politically correct/multiculturally sensitive agenda. \n\nThey object to the word 'Christmas' being replaced by the word 'Holidays'. They object to 'Merry Christmas' being replaced by the phrase \"Happy Holidays\". They object to the more religious aspects of Christmas (the baby Jesus, the nativity story, etc) being downplayed in favour of the more secular aspects of Christmas (the Christmas tree, Santa Claus/Father Christmas, etc).\n\nThese people feel that the Starbucks cup is just another example of this trend.\n\nTo be fair, though, I think the controversy is being overblown. Sites like Gawker and Buzzfeed will often notice a couple of tweets or an article from some blog somewhere, and then try to turn it into a whole \"Conservatives are angry about / launching a campaign against X!\" type of story.",
"A Fucking self proclaimed evangelist named Joshua Feuerstein made a video that went viral to try steer the religious sheep in protest against Starbucks, accusing them of waging war on Christmas. He's a Fucking bigot.",
"It seems like any kind of media outlet (NBC/CNN/FOX, etc.) just reports ~~news~~ opinions that they want their viewers to adopt; they are just making impressionable people *believe* what they're saying to be factual and that they need to be just as offended on *this* side or *that* side. For most people, they find unity only once they have found an enemy.",
"[People are obviously selectively \"offended\".... they don't even bother to look around the store and see the other products they're selling.](_URL_0_)"
] |
Why do movies from the 60s and 70s (Dollars Trilogy, Spartacus, Lawrence of Arabia, Bond films) appear to be both visually sharper/textured, more saturated, yet less deep/dimensional than films from the 80s up to the present? | [
"I don't think I agree with your premise, but there are several things that could be going on.\n\nFor one thing, movie prints can fade and need restoration. The older movies you speak of are all classics and you've probably seen carefully restored versions of them. Whereas most movies from the 80s may be too new to get that treatment.\n\n(Or, if you're talking about DVDs to be specific, too new to have gotten that treatment at the time they were digitized).\n\nAlso, the movies you mention were all such major productions that they would have had top notch cinematographers; it wouldn't surprise me if the average movie from the 80s had worse production values than the best movies from the 60s.\n\nDo you have any examples of 80s movies you mean? And what do you mean by 'deep/dimensional'?",
"What do you mean by deep / dimensional?\n\nThe second question: Have you seen any of these films projected?\n\nBecause they're all shot in completely different formats: Lawrence of Arabia in 65mm, Spartacus in Technirama (a 35mm-based format similar to VisaVision), most of the classic Bond films in anamorphic 35mm, the Dollars / Man with No Name Trilogy in an Italian 2-perf 35mm format called Techniscope. \n\nWhat they do have in common, though, is that they're shot on much \"slower\" film stocks. The speed of a film stock or digital sensor (both are rated in ISO) refers to its sensitivity to light. \n\nThe higher the ISO, the \"faster\" the stock and the more sensitive it is to light. But it also means it's grainier. Modern movies shot on film (quite a few still are) mostly use film stocks rated around 250 or 500 ISO. That means they can pick up a lot more in darker areas, but are also grainier. \n\nBy contrast, A Fistful of Dollars was shot on film stock rated at 50 ISO, which has very, very fine grain, but requires a lot of light."
] |
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