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In England all energy providers provide energy from the same grid, how comes they are all able to sell the exact same product at differing prices? And why is there competition between them?
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They basically just keep track of how much energy they provided to the communal grid, and how much their customers drew from the communal grid. They can produce it at a certain price, and prove their customers drew that power out the other side, so it doesn't really matter where the specific electrons came from as long as they provided enough for their customers' use. Make sense?
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Different power grids, different voltages, different safety standards and laws.
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why noises like nails on a chalkboard are so offensive to human ears and how it can make your teeth and mouth feel bad and give you goosebumps.
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The sounds emitted by things like nails on a chalkboard, knife on a plate, sirens, babies crying, etc., have a lot of 4 khz in them. That's the frequency where humans are most sensitive (average human hearing is from 20hz to 20khz). Since the 4k mid-range is where we're most sensitive, a little bit goes a long way.
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The sound vibrates through your jaw bones as well as through the air to your ear drums. You can test this by tightly blocking your ears and humming.
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Why is our calendar set up the way it is?
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Depends upon what you mean exactly. The calendar we use today is known as the Gregorian Calendar. However, the Gregorian Calendar is simply an "update" to the Julian Calendar, which was itself an "update" to the Roman Calendar, which was probably based off of Greek Hellenic Calendars, which were more or less all based off of lunar cycles. Each consecutive iteration of the year calendar simply made attempts to make it more accurate; obviously it's still not perfect, since we need leap years, but it's pretty close. Months were originally based off of lunar cycles, but now have been modified to fit the requirements for a more accurate yearly calendar (which is why full/new moons *kind of* align with months, but not really). Weeks are as long as they are, because 7 days is *roughly* a quarter of a lunar cycle. The history is a bit more complicated than that, but that's the really simply answer. Days, obviously, were just how long it takes the sun to reach the same spot in the sky again.
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Solar calendars are better at tracking seasons. People in regions that get the 4 standard seasons tended to develop solar calendars. People close to the equator who tend to get wet/dry seasons instead tended to make lunar calendars. Some cultures made both, and the Maya had very complex calendars that were lunar and solar as well as calculating things are longer cycles of a few years, dozen years, centuries, and thousand years.
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How rich was Mansa Musa?
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_URL_0_ This article from oct 2012 put his inflation adjusted worth at $400 billion The source they give is 'celebrity net worth' the methodology they used was just applying inflation adjustment to the gold price. They did not account for other sources of wealth such as land ownership. It also doesn't account for the gold price inevitably dropping when a market is flooded with it. They also give a neat list of the also-rans for comparison:) 1. Mansa Musa I, (Ruler of Malian Empire, 1280-1331) $400 billion 2. Rothschild Family (banking dynasty, 1740- ) $350 billion 3. John D Rockefeller (industrialist, 1839-1937) $340 billion 4. Andrew Carnegie (industrialist, 1835-1919) $310 billion 5. Tsar Nicholas II of Russia (last Emperor of Russia, 1868-1918) $300 billion
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I couldn't say how much money he had on hand, but Frederick Douglass was certainly doing doing well for himself. Perhaps the most famous, if not the richest, then, but after all not being a slave or a tenant farmer was quite an achievement by itself. After the turn of the century, however, we have Madam C.J. Walker, who is credited as being both the first African-American, and first female, self-made millionaire, through her beauty product company.
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Does making a Facebook status really secure your privacy/intellectual property etc.
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No, it's not legally binding and not agreed to by the service provider (Facebook). The only thing that counts is the terms agreed to upon creating the account or subsequent alterations they make you agree to in order to keep using their service.
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Just because it's not broken, it doesn't mean there's no room for improvement. One factor is that the people who actually make this stuff are engineers. The problem with engineers is that they're always looking at things and thinking "I can do better", and so a lot of change is simply for change's sake. But also on the business side, you can't allow your site/application to stagnate, otherwise a competitor will come along with a new feature and you'll lose all your customers. It's why Facebook are always making changes. They may be the biggest social website now, but if they stop working then they risk another company coming along and doing to Facebook what Facebook did to MySpace.
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What's the diference between organic and inorganic matter?
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Organic matter is matter containing carbon bonded with hydrogen and other elements. Inorganic matter does not have these C-H bonds.
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Organic matter technically means carbon compounds. Carbon and other atoms were formed in stars and blown out by supernovas. Then on Earth the first organic molecules formed through noon-living chemical processes, driven by things like lightning.
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What is Taiwan's status? Is it independent? Semi-independent? When exactly did the PRC claim it as "theirs"?
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'Taiwan' as a nation does not exist. It is the 'Republic of China' and is all that remains of the old chinese state that was overthrown in the civil war which created the 'Peoples republic of China' (mainland china today). The republic of china and peoples republic of china are entirely separate and very antagonistic towards one another. The PRC refuses to recognise the ROC as a legitimate state and the ROC claims (though the issue in now debated by Taiwanese nationalists) to the the legitimate government of China. Taiwan is a democratic state with an elected President and its own armed forces. _URL_0_
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Taiwan wasn't a member in the sense that the UN decided to give one little island a permanent seat. They were recognized as the true government of *all* of China, and had a strong presence there until they were eventually forced to flee the mainland to Taiwan in 1949. By 1971 the People's Republic (communist China) was obviously there for good, and gained more international recognition, so China's seat was essentially given to them instead of the government in Taiwan. Source: _URL_0_
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Why does antisemitism refer only to the Jewish people even though the term "Semite" encompasses both Arabs and Jews?
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Because the term was coined by people who used it to refer to groups that specifically hated Jews (Such as the Nazis), not groups that hated Jews and/or Arabs (For example, the Nazis got along pretty well with the Arab world, especially because of their shared antisemitism). _URL_0_
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It is not anti Semitic to oppose the occupation of palestine. The opposition of Zionism is a different matter, its far to broad a thing and could easily encompass anti Semitic ideals. It all depends on the connotations.
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Why do BBC and Reuters get sourced so much more often compared to American news sources?
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British television news (but not printed newspapers or online-only sources) are required by law to present an impartial point of view. Although this applies equally to all broadcasters, the BBC is by far and away the best-known British television news organisation internationally. Additionally the BBC's funding method means that it's far less likely to be influenced by advertisers or other forms of commercial product support. Reuters is (or at least started out as) a newswire service rather than a publisher of news to consumers. Therefore its stories often report just the basic facts of what happened rather than attempting to put any kind of editorial or political spin on the story.
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Reuters is a 'wire service' also called a 'news agency', their main role is to provide bare-bones news to other news outlets. However, they don't do much of the wider context stuff such as explanations, analysis and commentary, most people prefer to read their news from sources which are written to their demographic. _URL_0_
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How come you can say "take me to church" or "take me to school", but it's "take me to THE store, THE zoo, THE mall"?
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There are two things going on here. Typically, people only have one home, one church, and one school, so these words can be without articles. Other words require them. When a word requires an article, "the" can be understood to refer to a default choice understood by both the speaker and the listener. "Let's go to a Chinese restaurant" means any available Chinese restaurant, probably the closest one. "Let's go to the Chinese restaurant" means the one close to where we live, the one we go to all the time. Put those together, and you have: * a - any particular place * the - the primary, default place, as oppose to others * (no article) - a singular place
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In the context of "I'm going home", "home" functions as an adverb modifying the verb "going." Compare with other adverbs such as: "I'm going now." "I'm going quickly." It is not functioning as a noun in that sentence unlike "work", "supermarket" or "Paris" which require the addition of a preposition to make the sentence make sense. EDIT: For the skeptics, it's right in the dictionary: [_URL_0_](_URL_0_) Home, as an adverb, with a sentence like this used as a definitive example.
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Why does friction create heat?
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For friction to occur, 1 or more bodies must be moving, moving basically means it has energy. Friction slows down the 2 bodies in contact, but the energy is still there, and basically it gets converted into thermal energy, casing heat. Energy is merely transferred and not created. (If you rub your hands together, you may notice the harder you push your hands together while rubbing, the slower you'll be able to rub, because of friction. So you have to move your hands even harder, adding energy, to keep them at the same speed, the more energy, the hotter your hands will get)
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heat is energy. it takes energy to move your hands the resistance you feel as friction is the dissipating that energy into your hands you feel that as heat.
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How does the brain develop personality?
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Your life is an endless set of ongoing probabilities and outcomes. This experience, channelled through a brain with a number of particular derivations established through genetics, combine to give you a unique means of interacting with the world, hence, a personality.
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This is a topic not thoroughly understood, but some mechanisms have been noted. Some things such as small alterations in a hormone or receptor (due to a small nucleotide mutation generally) can make it less or more effective, thus altering behavior. I believe oxytocin is a commonly cited example of this. Apart from this, nurture is also at play, since people generally grow up learning from their parents, and naturally may develop some of their personality traits.
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LI5 Explain to me how a salad from McDonald's could be "less healthy" than a salad from anywhere else.
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You can call anything a salad. If you use ingredients that aren't healthy, the salad isn't going to be healthy. Lots of times it's the dressing that's the culprit, or croutons, or fried meats or something like that.
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It’s only ‘worse for you’ if all of your nutrition comes from McDonald’s or you eat more calories than you use. It’s a larger burger, it has more calories. More fat, more protein, more carbohydrates. You can eat McDonald’s and simultaneously be perfectly healthy, as long as you’re incorporating it into your nutrition needs.
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What would a 1 atom thick blade be like?
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It would do absolutely nothing to you. There is already a lot of empty space between the atoms in your body. A single atom thick blade, ignoring the fact that such a structure would lack enough strength to actually withstand striking a body, could easily pass between the space between atoms and have no effects on the atomic or cellular bonds. And if it did manage to separate some bonds everything would still be so close together it would just reform. The reason a knife works is because it pushes stuff far enough apart.
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You're assuming that the knife itself is going to maintain integrity. That's not a reasonable assumption; when you start getting close to a single atom wide, your knife is going to break very quickly.
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If opposite sides of magnets attract, why does the north side of a magnet point to the North Pole?
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Quite simply, you're looking at the names backwards The planet's poles were named because direction the magnet points, not the other way round :-) North on Earth is the direction the North end of a magnet points. The North pole is actually the "south" magnetic pole of the Earth's magnetic field.
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First, magnets are north and south, not positive and negative. We make this distinction because magnetism is not like charge, where you can have positively charged particles and negatively charged particles. To our best knowledge you can only have things with a north and south "pole" rather than charge. But yes, you can measure the current through a loop of wire and "poke" the loop with one end of the magnet. If you're looking at the loop from the same side as the magnet, and you're poking the magnet into the loop, if the current goes counterclockwise around the loop then it's the north pole that you're poking into the loop. If the current goes clockwise, then it's the south pole.
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Other than Rome, did any other Empire ever practice appointment of Emperors through merit?
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It's also worth noting that in the Roman time period you're specifiying, the meritocracy as you call it was probably a result of circustance rather than a cultural or political movement that embraced a more technocratic outlook. Augustus for one, wanted to leave the Empire in the hand of his direct family...but his family had a bad habit of dying. Tiberious, while worthy to take the job based on merit (you can argue how well he did as Emperor, especially in the later years but he was a distinguished solider/statesman) but Augustus did not think about appointing him into he was the only choice. Most (all?) of the Emperors in the five good emperors period did not have living or capable sons when they needed them. Adopting heirs was a tradition in Rome, so the Emperor got to choose. We can at least give them credit for making some good choices though. If they had healthy, adult children when they needed them, the Emperors would likely have chosen their biological heirs to take over.
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The problem for an emperor is there were several flashpoints in the mid-Empire: Germany, the Danube, Mesopotamia. He could take charge of one army but the other two (or more) spots would require he give a general command of a lot of legions. And a general with an army is a usurper in waiting. The tetrarchy was an attempt to fix that by appointing a junior co-emperor at first and then expanding it to a total of four emperors each with their own army covering the four hot spots of the empire. The idea being that the senior Augusti would retire and the junior Caesar would be promoted to Augusti and two new Caesars would be chosen, etc... However the system broke down immediately following Diocletian's retirement as Maximian was unhappy at getting forcibly retired and Constantius wanted to pass power down to his son Constantine. A nice idea but couldn't deal with ambitious men.
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Why is inflation, like death and taxes, always so certain? Why does currency always lose value over a period of time?
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Inflation isn't always certain, but it usually happens because countries usually try to maintain low rates of inflation for their economies. Low inflation rates are generally preferred because they encourage investment without making people's current savings worthless. Inflation encourages investment because money sitting in a bank account loses value when there's inflation. If money sitting in a bank loses value, people are more likely to invest it somewhere where the money can grow steadily. Deflation discourages investment because your money will increase in value by just existing. Why risk investing in anything if your money is going to become more valuable over time anyway? Of course you don't want to have high inflation because then people's savings may become worthless too quickly.
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It causes inflation. When the total money in an economy (the money supply) increases too rapidly, the quality of the money (the currency value) often decreases. Economists generally think that this money supply increase (monetary inflation) causes the goods/services price increase (price inflation) over a longer period. & #x200B;
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How can a doctor check for HIV with a cheek swab if kissing someone with AIDS won't cause me to get AIDS?
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Because when cheek swabs (buccal swabs) are taken, what is really being looked at are the epithelial cheek cells scraped from the inside of the cheek. These contain DNA which can then be analysed to see if HIV is present. You cannot catch HIV from the saliva/cheek cells of another individual as the virus would be needed in very very large quantities in order to become infected and the saliva of an individual infected already with HIV would not possess enough HIV to ever infect, regardless of severity of illness.
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AIDs is spread by the virus (HIV) being absorbed into the bloodstream. As I understand it, the virus wouldn't make it into a persons saliva, so you wouldn't be able to transmit it through kissing, unless the person with AIDs had their infected blood in their mouth (in which case, why would you kiss them?). For other questions about AIDs transmission, including the answer to the risk of oral sex, check out [this FAQ](_URL_0_) from AID Atlanta.
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If a feather entered the Earth's atmosphere, would it burn up? Or would it just slowly fall to Earth?
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Things burn up on entry because they hit the atmosphere at great speed and cause the air to compress and heat up. A feather falling into the atmosphere wouldn't have enough kinetic energy to do that. The atmosphere would slow it down and it'd eventually drift down.
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It's more sensible to ask why they wouldn't? The only reason that a feather falls slowly in normal human experience, is because it's not heavy enough to push air out of the way - the air delays its descent. In a vaccum, there is no air so it falls at the normal standard speed of any object.
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Why do cars allow you to keep the a/c setting on even when the heat is turned all the way up?
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In the fall and winter it is advisable to have your A/C on with the heat to dry out the air in the car a prevent fogging the widows and wind shield. In fact when you turn on your defogger/defroster, your A/C automatically turns on.
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The temp knob controls the mix of cold air and hot air. Hot air is generated by waste heat from the engine. With the A/C off, cold air is from the outside. So the coldest it can get is the ambient outside temp. With the A/C on, cold air is from the A/C system, which can be colder than the outside temp (in spring/summer, at least).
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Was the Incan empire a communist or socialist civilization?
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Well, neither is really applicable. Both are economic philosophies that didn't really exist at the time. But, I understand what your question is getting at. They were more socialist than communist, but as I said neither term really explains it. The system was based on bartering, taxes, and providing for yourself. The government provided welfare, but this wasn't done in a way that we'd identify as socialism in modern day. Their economy is what is described as a 'vertical archipelago' traditional economy. It roughly means an agriculturally based system of public service, which they called "M'ita". Services were conducted by men in the M'ita. M'ita was divided by agriculture, fishing, military service, etc. They worked for the Empire, but were able to provide for their families. The 'State' did not own everything, as in communism, but did not redistribute wealth, as in socialism.
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This question is not inherently historical, rather political. Without futher defining what we mean with communism, it would not be possible to answer from a historical viewpoint.
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How are microorganisms extracted from soil and air samples for further study?
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I TA'ed a lab course where we grew microbes from soil samples and the protocol was just to put a small amount of soil in a larger volume of water and shake/vortex for 5-10 minutes, then plate aliquots of that water on growth media. It's not a super complicated way, nor do I believe that it gets every single microorganism, but it gives a good sampling. As for isolating from air, I think the typical method is to use a weak vacuum pump with a 0.22 micrometer filter that pulls in surrounding air. The filter can then be pressed onto agar to obtain colonies.
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The pathogen is usually grown in vitro (on cell culture) or in vivo (in suitable animal hosts), which yields many organisms for experimentation. It is then periodically re-cultured on fresh media (ex. a fresh cell culture) or in a new animal to ensure that you have a viable population of that pathogen. If you don't want to study active pathogens, you can also study the small amounts of DNA/RNA you may have collected from inactivated specimens. The DNA/RNA can be amplified using a method called [polymerase chain reaction (PCR)](_URL_0_), which produces several million copies of the DNA/RNA molecule which you can use for experimentation. EDIT: Typos and clarification.
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How would a European blacksmith fare in east Asia during the Middle Ages?
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Could you specify whether you mean "blacksmith" as a general metal worker, or do you mean "blacksmith" in the more technical sense: an iron worker? (i.e. a bladesmith is a related but different trade to a blacksmith)
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Could you please specify when and where? The "middle ages" are a long time and Europe is big.
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Out of all the money in the world, how much of it is a digital number on a computer system?
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IIRC physical currency accounts for about 2-10% of all money in the US and this pattern is seen across the world. I think the current global estimate is that only 8% of money is available as physical currency. So somewhere upwards of 90% of the money in the world is digital _URL_0_
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1024 is 10000000000 in binary - and computers "think" in binary. It may not sound like a round number to you, but it is to a computer. (1000, on the other hand, is 1111101000 in binary - much less round.)
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Why do bubbles from my carbonated drink stick to my straw and when having a straw with a stripe, why do bubbles stick to the colour stripe and not to the white stripe?
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Wettability and surface tension. The dye changes the wettability of the plastic which affects the bubbles “wetting angle” (how “tall” vs how “flat” the bubble is) which is directly related to the surface tension of the liquid. Too big or small of an angle and the bubble can’t stick.
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Soda is stickier than water. Foam is the fluid sticking to escaping gas. Water slips off bubbles really easily but the soda doesn’t.
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Did sailors firing cannons on large man-o-war ships suffer permanent hearing loss that prevented them from performing their duties, and were they ever discharged from service because of this?
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Follow-up question: what of soldiers in large companies, firing off muskets before ear protection was created?
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While the explosion was very loud, being heard nearly 3,000 miles from the source, no, entire villages were not deafened. The sound up to 100 miles from the source registered 172 decibels (the human threshold for pain is 130 decibels). However, in the case of the British ship "Norham Castle" (which was 40 miles away at the time of the explosion) half of the crew was deafened. In the captain's journal he wrote,“So violent are the explosions that the ear-drums of over half my crew have been shattered. My last thoughts are with my dear wife. I am convinced that the Day of Judgement has come.”
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Why our eyes redden when we cry even when we don't rub them with our hands?
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The process of crying involves inflammation, size increases in the blood vessels in the eye (vasodilation) and water retention. It might also involve thousands of tiny salt knives chopping up your eyeballs, though. Who knows.
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You have these pouches in your eyes called the tear ducts and they are used to lubricate your eyes all the time, not just when you cry When some people yawn, they squeeze their eyes, pushing the tears out of the tear ducts. Edit: my mistake
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What's wrong with my hypothetical thought experiment that would allow us to see our own planet in the past?
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There's nothing wrong with this idea, but because it will take us at least 50 years to get there (or to some random spot 50LY away), you won't be able to look back farther than whenever you build the TV camera/giant mirror. So unless some aliens are already watching us and recording it, you won't be able to go see the JFK assassination. Practically, the light from Earth would be so dim and noisy that you wouldn't be able to see anything detailed.
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How do we notice most of the planets in our solar system? We observe them because light hits them and bounces back for us to see. The further away they are the harder they are to see, you get to Saturn and you can't see anything with the naked eye. Further out you need binoculars or a telescope to see them. In fact Neptune was only discovered because we noticed Uranus wobbled a bit when it shouldn't. This wobble in fact lead us to think that there was a planet between Mercury and the Sun as Mercury also wobbled a bit funny. As it turned out there is no planet and this movement was explained by general relativity. Pluto isn't visible from Earth at all. Interesting fact, Pluto is so far away from the Sun that it hasn't completed a full orbit since its discovery in 1930. Now look at this proposed planet, it's orbit is MASSIVE compared to Neptune's. It's going to spend most of its time in darkness and without many objects for us to observe nearby we can't easily infer its presence.
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How do glute muscles become weak?
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The same way any other muscle gets weaker. Over time and extended periods of low use, they deteriorate and lose mass.
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In a couple of different ways, actually. First and foremost they get stronger with lots of exercise because they get better at recruiting more fibers and contracting harder, which is mainly due to the training effect on your central nervous system. Secondly the muscles themselves get little micro tears in them as you lift weights. When these little tears heal back your body heals them back bigger and stronger than they were before.
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Where do/did US presidents stay when traveling aboard Naval vessels?
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They would generally be offered accommodations in the captain’s or admiral’s quarters, both for reasons of security (those are restricted parts of the ship) and also space to work and meet with their staffs. *USS Iowa* famously has a bathtub installed in its captain’s quarters, put there for the use of FDR on his way to and from the Tehran Conference in 1943. That trip is notable in part for the hapless destroyer *William D. Porter* accidentally launching a live torpedo at the *Iowa* during a drill. The ship successfully evaded the fish, but there was brief panic over some sort of assassination plot. The captain and ships’s crew were placed under arrest.
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Do you know what state they were from? The lists are broken down here at the archives .gov website by state and service branch : _URL_0_ I linked you the Navy/Marines/Coast Guard database because the Battle of the Coral Sea wad a naval battle, notable as the first time two fleets fought one another without ever seeing each other physically. He was likely a Navy pilot
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If I hold two open wounds on either arms together, will they heal together?
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Yes, absolutely. This phenomenon of two separate wounds healing in to one piece is used for a variety of surgical techniques, and extensively in reconstructive surgery. EDIT: [Here's an article on one of the pioneers of reconstructive surgery. He fixed people's noses, aaaallllll the way back in the 1500's](_URL_0_)
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The short answer depends on just how ill you are. If you're so ill that you're in a protein and energy deficient state, it would make healing much slower, even impossible. If you're not critically ill it would make little difference. If you had another local wound or source of infection near the unrelated cut, perhaps healing would be slightly increased due to increased blood flow.
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Why can DDoS attacks not be prevented by only allowing registered IP addresses to connect, preventing overwhelming traffic?
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Three reasons really: 1) It'd take time out of the ISP's day to keep them up to date on the IP the person currently has leased, and it'd be a hassle to make sure that it was genuinely the account holder that expressed the wish to let the network be kept up to date. This hassle means the ISP wouldn't do it without getting paid something. 2) It'd increase latency. Now every incoming packet has to have its source IP matched against a very, vary long list of IPs before all the other processing. 3) It makes DDoS easier. Since it now has this extra processing of checking the source IP against the list it'll take more processing power per packet received to deal with traffic. It'll have to do this check, and therefore all that processing, to find out whether to drop it or not and therefore you can use any IP address you want to force the system into running the check.
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No protection is absolute. A even "bulletproof" vest is technically only bullet resistant. A DDOS attack is basically a tug-o-war. DDOS works by having a bunch of computers team up to flood one site. This adds all of their bandwidth and resource demands together. If the combined load is more than the site's capacity then it will go offline. The defense is to have a lot of bandwidth and to discard the bogus traffic with as little resources as possible. An example would be blocking an IP address at the router. Services like CF have high bandwidth connections and controls to weed out and discard bogus traffic. There are many tricks, but the general idea is to discard the bogus traffic with the least amount of resources to tip the scale in your favor. Ultimately the winner will be determined by who has more resources, the attacker or the defender.
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How/Why does highway traffic occur, what is the science/math behind it?
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There is an entire field of traffic engineering that goes into this. One obvious cause, roads are built with a certain capacity. Based on speed, number of lanes, etc. a road should be able to handle a certain number of cars per hour with no delays. But, if you have more people getting on the highway than off at a given section, traffic behind an entrance ramp is going to have to slow down or stop in order for people to get in.
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You can actually have traffic jams that cascade without any kind of accident! Imagine a freeway with moderate traffic. Everyone is going at a good speed. Now imagine at some point a driver gets startled and taps his breaks. He doesn't stop, or really even slow down that much, but for a split second his break lights are on. The woman driving the car behind him sees his break lights. Anticipating him slowing down, she has to hit the breaks a bit. But because it takes us all a little time to react to something, she actually has to slow down a little bit more than he did. The person behind her now has to slow down even more. This cascades over and over until eventually someone has to stop. There's your traffic jam. The funny thing is, the guy who actually started the whole thing rolling has absolutely no idea because he's already miles ahead.
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Why is sugar so rewarding?
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Can someone answer this question on a biochemical level, i.e. 'How does sweet stuff on the tongue register as rewarding in the brain?'
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Sugar is sugar. The difference is that “natural” sugar, such as that found in fruit, is accompanied by a large amount of fiber. This fiber fills you up, potentially causing you to eat less of it. Added sugar such as what you’ll find in candy, soda, etc. are generally not accompanied by a large amount of fillers, allowing you to eat much more without feeling full.
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What are those vertical columns of smoke often seen next to a nuclear explosion?
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Those are smoke rockets, shot up just before the detonation to allow the shockwave to be observed.
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The spots are essentially the vaporized remnants of bomb casing and test stand. The spikes are vaporized guy wires. I hate to use Wikipedia as a source, but its articles on the Trinity test and surrounding topics are surprisingly well-written. _URL_0_
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Why do carbonated beverages have streams of bubbles coming from seemingly nowhere?
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The bubbles are carbon dioxide gas. The gas is initially dissolved in the liquid, like you would dissolve salt or sugar in water. However, as pressure and temperature decrease, gases become less good at being dissolved - they become less soluble. This causes some of the dissolved gas to be converted to normal carbon dioxide gas, which bubbles through the liquid.
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The amount of dissolved gas in a liquid depends on the temperature of the liquid and the pressure above the liquid. If the water is cold and warms to room temp the bubbles might be atmospheric gasses like N2 and O2. Equilibrium has shifted and the amount of gas that is soluble in that volume of liquid is lower, some gas will leave. Bubbles can get trapped at nucleation sites in glass which are tiny imperfections or scratches on the surface of the glass.
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Does sign language have slang or colloquial language?
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It does. Sign language varies between countries and even between regions. A sign that means one thing can mean a completely different thing on the other side of the country. Consider that unlike spoken and written English, which was easier to standardize offer distance (telegraph, telephone, written mail), sign language was very hard to travel distances before video broadcasting, so it was more susceptible to change Note: I'm not an expert, or someone who is part of the Deaf community. I just happen to have a little bit of knowledge from a friend who did some work with those in the community. I could be completely off base here
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Koko, the most famous of the gorillas that learned sign language, did a [live chat](_URL_0_) with people over the internet back in 1998. If you read through it you can tell that it's hard to determine how much exactly she understands, and how much of the conversation is colored by the person doing the interpretation.
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Why does THC have such a long half life while other drugs such as meth have a much shorter half-life?
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THC is fat-soluble. Meaning when you smoke weed THC is stored in the fat cells, meth and many other drugs are water-soluble. You could drink enough water to flush meth out of your system for good. With THC, water only dilutes it for a short amount of time and cannot flush your system because it is stored in the fat.
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Drugs affect the human body by binding to *protein receptors* (either to turn them on or turn them off). And one drug molecule binds to one drug receptor. The more drug molecules you have in your body, the more protein receptors are bound, and the stronger the drug effect. However, for some protein, you need to cover a minimum number of receptors to feel the effect at all, thus, the effectiveness of the drug will wear off long before you reach the half-life point. For others, you do not need to cover every receptor to produce the maximum effect, thus, you will feel the full effective of the drug will extend long past the drug's half life. Generally, a drug is considered to be completely cleared from your body after 5 half-lives. Furthermore, different people breakdown drugs at different speeds, thus, the duration of effect of a drug for you may be different than for other people.
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Why is coloured hair (such as blue and green) considered "unprofessional"?
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Because it's not a natural hair color and is typically seen as distracting for a professional environment.
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Pretty sure it's because our hair color is dictated by different ratios of the expression of two or three different kinds of melanin pigments. Their possible combinations are what we see today. They simply can't combine to make green, blue or purple.
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Considering they had printing presses, why were important documents hand written until the 20th century? Things like constitutions and treaties seem like they should have been printed
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You can't type on a printing press the way you would on a typewriter or computer keyboard. Setting up the press for a print run was a slow process carried out by a specialist who would need a reference. This was done for documents of interest to the public, but I don't suppose the authors of those documents wanted to wait for a printed copy to become available when they could just sign the hand-written original instead.
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Because not everyone who needs documents signed has computers. In many ways if you need a piece of paper that has a signature, sending it from machine that reads paper directly to machine that prints paper could certainly be more efficient. SO the main reason is that we're still dependent on paper records for things, and this is a good way to send them. The machines themselves are often terrible, but the concept is still necessary.
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What exactly is determinism?
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Determinism is basically the view that free will is an illusion, that everything that happens is determined by the arrangement of particles and energy when the universe began, that events cannot unfold any other way than the way they will unfold. The rationale is that human beings are (chemical) machines, and that no matter how deeply you look, there are no chemical processes that demonstrate mechanisms that can't be accounted for through careful observation — There's also many documented psychiatric cases and personal experiences where the sense of free will is reduced or disappears, and much research showing that the human brain makes "decisions" before the person is aware of making them and makes up reasons for those decisions afterwards. In short, there are many clues that human's sense of free will is an illusion created by the mind.
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Quantum mechanics the way we currently describe it is also in itself completely deterministic from a 'god perspective'. For a given Hamiltonian and initial state we can describe the complete evolution of the system, however the state can not be characterized in observable quantities. So at least in the many world approach to measurement the situation is very similar to Bohmian mechanics. There we also have deterministic evolution of the system, but even though there a state can be described in terms of observable properties it also cannot characterized by measuring parts of it. Again it is deterministic from a god perspective, but presents itself seemingly indeterministic to a restricted observer.
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Why is the Mississippi River used as the dividing line for "best of" or "worst of" i.e. "Best BBQ East of the Mississippi "?
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Back when the USA was still growing, that river was seen as the symbolic boundary of the known part of the country. "Best x east of the Mississippi" basically meant "best x in the whole civilized part of the United States."
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The bigger river is the main one. Look at the convergence between the Mississippi and Missouri rivers [here](_URL_0_). The Mississippi river is the bigger one. It's worth noting that you are sort of working backwards here. The Misssissippi was named downstream, at the mouth, and then mapped backward to the source. This is simplified but... it's less a matter of following the Mississippi down to the spot where it joins with the Missouri and then figuring out what to name the resulting river, and more a matter of following the Mississippi upward, coming to a fork in the river, saying "ok, the larger side is the Mississippi, so we need a new name for the smaller branch leading in"
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What causes the blackened skin under your eyes when you don't get enough sleep?
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"The physiopathology of periorbital hyperchromia (which is the word for dark circles under the eyes) is not clearly defined; however, blood flow stagnation seems to be a determinant factor involved in the development of this process. This concept is supported by the fact that in the last years, cosmetic companies have been presenting preparations for ‘‘dark circles’’ containing mainly ingredients for stimulating local blood flow." ([Source](_URL_0_), p.129)
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Its the secretions aka tears that lubricate our eyes, it evaporates and leaves behind a residue, sleep in your eyes or as my ex girlfriend called them, eye bogeys.
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What books do you recommend for the WWII Europe theater, foreign relations, or other books?
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*The Rise and Fall of the Third Reich*, by William Shirer. I swear by that book. Shirer, who lived in Nazi Germany himself, goes into exhaustive detail on nearly every conceivable subject regarding the Nazis. As you'll no doubt be happy to know, about 3/5 of the book is devoted to the war in Europe and he writes extensively about the diplomatic maneuverings, especially in regards to Nazi aggression towards Czechoslovakia and Poland, although he covers most of it. The only down side to you is that he focuses primarily on the German perspective. If you want to read about life in Britain during the war, you'll need to look elsewhere. Nevertheless, I **highly** recommend it. Edit: missed a comma.
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Ken Burn's *The Civil War* and *The War* (WWII). And if you really want "to learn a lot", I would suggest some historical books... Some are quite easy to read and accessible!
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Why does sunrise look so much different than sunset?
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At sunrise the air is often calm and still and cold while at sundown the wind is blowing and the air is heated after a days worth of sun. This means that at sundown there are often more particles in the atmosphere which contributes to the light scattering. These differences make for different appearences in sunrise and sunset.
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For the most part, they do appear the same. Painters have a hard time differentiating between the two. We sense a difference because of other senses, like smell, temperature, etc. On the other hand, sunset/rise is colored because of particulates in the air. The light reflects off of the bits of dust and pollution, making rainbow colors. Theoretically, if we are producing significantly more pollution during the day than at night, sunsets would be more brilliant than sunrises, when the air cools and particulates settle out of the atmosphere.
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What feature of a battery determines it's output voltage?
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All alkaline batteries, AA, AAA, C,D, 9V all have voltages of 1.5 volts per cell. Peel the cover off a nine volt, inside are six AAAA size cells connected in series. Remember, electrical sources in series (end-to-end, positive to negative in a row) add voltage. Sources in parallel, (all positives and all negatives together) add current. So, the alkaline reaction produces a 1.5V electrical potential, the lead-acid cell produces 2V, a car battery has 6 cells in series. The size of the electrodes and volume of electrolyte determine maximum current, and capacity. A truck battery, like in my fire truck, might produce 950 amps, the battery in my motorcycle, with much smaller plates, 300 amps. Nickel-Cadmium, 1.2V per cell. and so on. Long story short, voltage is determined by the electrochemical reaction, current by the size of the electrodes, and capacity by volume of reagents in the battery.
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It doesn't "know". The electrons don't move because there is not pathway. When you hook up a battery or some other voltage source, not only are electrons pushed one way, but positively charged areas that can accept electrons are created going the other way. For short we call them "holes". Also electrons actually flow the opposite direction from what you would assume. When Ben Franklin decided to make one direction positive and the other negative, he had a 50/50 chance of being right. He was in fact wrong. So electrons actually flow from the negative side of the battery.
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Why don't fast food chains sell alcohol?
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Liquor licenses. Also, most of them are profitable enough that it isn't worth the headache, but I'm pretty sure Chipotle sells beers
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Market share. Everyone knows about McDonalds and Coke, but if they don't stay at the front of your mind their competitors will start to erode their market share. All the other players in those markets advertise heavily, if the market leaders don't some of the less devoted consumers may drift off to their competitors.
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The ball-tampering scandal in Cricket.
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Shining the ball is legal. Scrubbing the ball with something other than natural play is not. Think of the ball as two halves. One side is smooth the other rough. The difference between the two sides when it moves through the air at speed causes it to curve (called swing). A bowler then has the opportunity to make the ball swing in the opposite direction to that the batsman is expecting (called reverse swing). The older the ball is, the less it will swing so teams will try to use legal means that keep the rough side rough. The Aussies were using some sort of tape or sandpaper to do that which is illegal.
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Without going into the specific of how the idea is put into practice, the general rule is: * Players are governed by the rules of the sport, which often have "offences" and "punishments" which may be minor or severe. * The law takes the view that most of the time, this framework of rules is sufficient to deter crime and punish offenders. * However the law will step in if it needs to. Serious offences are often prosecuted by the law even if they happen on a sportsfield, because even the most severe punishment under the rules of the sport is insufficient.
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What is the oldest known example we have of humanity introducing an invasive species to a new area?
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Humans introducing themselves to areas outside of Africa. Although, this depends somewhat on your definition of "humanity", as there were several times in pre-history when hominids seem to have migrated out of Africa. If you mean "anatomically modern humans", or "homo sapiens sapiens" then this would be circa 100,000 years ago (although various pre-homo sapiens hominids had migrated out of Africa previously). At the time when homo sapiens sapiens migrated out of Africa they seem to have had no domesticated animals, and had not adopted agriculture, so they would not have introduced any new animals or plants to new areas. Other than themselves as an invasive species, they may have introduced their own parasites, and possibly (though less likely, due to sparse populations) some diseases.
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An interesting example is the [Greenish Warbler](_URL_2_). The species spread around both sides of the Tibetan Plateau, differentiating slightly into subspecies along the way. The two ends met again on the other side, but are now different enough that they are unable to reproduce. The intervening subspecies still exist all the way back to the source, and each can still interbreed with their neighbors, even though the ends cannot. This forms a [ring species](_URL_2_), showing the speciation process in geography that is often most observable in time.
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How much does a 15 minute 110°F shower raise your core body temperature (if at all)?
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Your body temperature would rise a tiny amount but it wouldn't be much, the body is good at regulating temperature and many vital bodily functions don't work well if the body's temperature is far from its normal temperature. As for the magnitude of the change, there are too many variables involved and I'm too lazy to estimate heat transfer coefficients right now.
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One important detail - 37°C is the CORE (i.e. inside your body) temperature. Your hands (which you most likely use to touch the water) are cooler, significantly so in some people.
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With the recent official discovery of anti-hydrogen, if a space ship were to fly through a large cloud of it in outer space, would it be vaporised? Or would something else happen?
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It wouldn't just be vaporized. It would be utterly shit-wrecked, like, worse than atomic explosions. This is because most of the atoms in the ship are bigger than hydrogen, and the matter would ionize heavily as electrons annihilate against the positrons, and then the bare nuclei of the ionized atoms would split as anti-protons destabilize them. Think a nuclear reaction, but instead of matter the size of an apple releasing 1% of their nuclear energy, 100% of several tons doing that.
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Like all substances, gas molecules in a contained space are constantly bouncing around against each other and off the walls of their container. Breach that container, and the molecules have nothing to bounce off of, so they'd just fly off into vaccuum. From our perspective, the gas cloud would rapidly expand, thinning as it goes, until it's indistinguishable from the normal vaccuum of space.
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Why do English Muffins seem to never mould compared to other breads?
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English muffins tend to be dryer, denser, less sweet, and saltier. They are also less likely to be baked in house or nearby, so more likely to have preservatives.
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For one, mold is an _URL_0_ such, mold needs to be in the environment if any is to grow on the bread. For going stale one factor is moisture. As water binds to starches in bread, they kind of straighten out and "harden." Of course too much moisture makes the bread turn to mush.
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Why do American colleges and universities spend millions of dollars on non-revenue generating athletic teams?
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They DO generate revenue. Just not directly. It is advertising for schools. Schools with great athletic teams have high numbers of applicants regardless of the tuition charged. Great athletic teams also result in generous alumni donations. Every time you watch "your" team play, it renews your sense of loyalty to your school making you more likely to send a donation when that letter or phone call comes.
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Because sports programs make money, so universities want them.
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Does light have momentum?
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Photons have zero mass. This is a very important property and bears special mention. A classical understanding of momentum isn't enough to understand why photons have momentum. Despite having no mass, [all massless particles have momentum related to their energy / wavelength / frequency.](_URL_0_)
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Yes. Light has momentum proportional to its frequency. The push is pretty weak though, if you held a 1x1 meter mirror up on to the sun you'd weel a push of 9.08 µN, equivalent of the mirror being 925.9 micrograms heavier, about the mass of 3 snowflakes. Read more here: _URL_0_
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How come the airline market has not consolidated into a few large companies?
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Actually the air travel industry has been consolidating. Just look at the last five or so years - we've seen Delta and Northwest merge, Continental and United merge, and U.S. Air and American Airlines merge...
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Many airlines started out funded at least in part by governments. But airlines can be started by bunches of people pooling their money together. You will find that most companies cannot be bankrolled by one immensely wealthy investor, but is a group effort.
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Why are Asia and Europe considered different continents?
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Both the idea of dividing Europe from Asia and Africa and the concept of a continent comes from Europe. So it is not surprising that European see Europe as a continent even if newer Earth science uses a different and more coherent scientific term for large landmasses. While several arguments can be made about the inconsistency of the references, Europeans will always see themselves on their own continent, and most of the world will always refer to Europe as a distinct continent. ‘Europe’ and ‘Asia’ was divided by ancient Greeks who were the first to referr to Europe as current Greece and Asia as current Turkey. They divided the world that they were able to travel on their ships into these two parts many centuries before the word 'continent' was invented. They divided what they knew as 'Europe' and 'Asia' and 'Africa'. According to the etymology of the word 'continent land' it was derived from the 16th century English term 'continuous land' meaning mainland or a continuous tract of land.
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Cultural reasons. You could argue that Africa also belongs to the same continent, as it is actually connected to Asia by land so it is also part of that land mass. Humans just arbitrarily chose to separate them into different continents. Same reason Greenland is not it's own continent, but Australia is.
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Why are Asia and Europe considered different continents?
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History. It goes back to the Greeks, specifically a guy named Herodotus. He wrote that the world consisted of Europe, Asia and Libya (by which he meant Africa). Over the years, the idea of Europe as distinct from Asia was cemented by the existence of a honking great *nothing* separating the peoples of Europe from the peoples of Asia. This meant there was relatively little migration of either people or ideas between the two regions, reinforcing their distinctness.
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Cultural reasons. You could argue that Africa also belongs to the same continent, as it is actually connected to Asia by land so it is also part of that land mass. Humans just arbitrarily chose to separate them into different continents. Same reason Greenland is not it's own continent, but Australia is.
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Is there a trade off that makes it hard for a virus to be both very contagious and very deadly?
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Yeah, viruses that are overly virulent kill their hosts before they are able to transmit the virus to new hosts, so more deadly viral lineages tend to burn out before being widely transmitted. So there's an evolutionary trade off between high virulence and a strain's ability to maintain itself in a population.
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Depends a lot on the type of infection. Some viral infections become contagious after you get a big enough viral load (how much of the virus you have in your body). Most viruses won't be contagious without the necessary viral load and its also directly tied in with the onset of symptoms (symptoms appear at certain viral loads). 'With bacteria is a different story because thye have different way of provoking illness: some cause it by multiplying and destroying normal tissue, some cause it by releasing toxins. For example a food poisoning won't be countagious if you only ate the toxins and not the bacteria. Also bacteria are way larger than viruses so they transmit harder through air but they are usually more resistant so they can subzist in the enviroment longer.
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How are there different temperatures of fire?
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Fire happens when something changes its form. Some things take less energy to go through this change. Heat is the release of energy. So fire is sometimes more or less energetic than other fires.
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There was a recent competition among scientists to explain fire to children _URL_0_ The winning video will explain everything you want to know!
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Experiment that proved that reality doesn't exist until is measured
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They don't know what they're talking about. There's a number of interpretations of quantum mechanics that would view very that experiment differently. The experiment didn't tell us anything new we don't already know.
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It was a thought experiment that a physicist named Erwin Schrödinger came up with to highlight what he saw as an issue in a theory of quantum physics. The theory basically says that certain properties of particles are undefined until they're observed. The thought experiment goes like this: You put a cat inside a sealed box with a radioactive substance that has a 50% chance of undergoing radioactive decay & a detector that detects whether an atom of the radioactive substance decays or not. If the device detects decay, it releases a toxic gas that floods the box & kills the cat. If no decay occurs, the cat lives. It's impossible to see into the box without opening it. However, since you can't tell whether an atom decays without observing it, the radioactive decay can assumed to have both occurred & not occurred, & so until the box is opened, the cat is both alive & dead at the same time in reference to the outside universe.
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how is it that ships are able to withstand extremely rough seas without snapping in half or receiving extreme structural damage?
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First of all, there is an internal skeleton that can resist quite a lot of twisting. Second of all, these ships *bend*. Like, a lot - metals are quite good at bending without snapping, and even returning to the original shape. Everything else is Naval Architecture 101 and beyond my pay grade.
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Because the ship is wide enough that rocking doesn't affect the balance as much as it does a smaller boat. Take a 10 cm stick and balance it on your finger. lift one end up 5cm and it will probably fall off your finger. Now take a 1m stick and do the same. It will probably still stay on your finger. It's the same thing for cruise ships. Because they're so wide. Lifting one end up doesn't change the angle of the deck that much, as a result it doesn't shake back and forth violently. You would need much stronger waves to shake a cruise ship.
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Why when TV shows use computers do they use fake operating systems?
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Two reasons: 1. Product placement. Companies pay good money for movies and TV shows to show their products, so the shows' producers wouldn't want to "give it away for free". They would also wish to avoid any possible legal and business complications if by any chance the company doesn't like its products appearing on a certain show or movie (even if it's legal). 2. [Viewer-Friend Interface](_URL_0_). Real life user interfaces are designed for people who sit closely in front of the monitor. They have lots of data. Showing something like that on a TV show would be confusing to the viewer - the display needs to be large and clear.
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Most tv shows portray hacking very unrealistically, however, people have said that Mr. Robot shows it the most realistically out of most shows and movies.
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Why do bees not see the glass?
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I think we need to take a step back and consider that there might be a simpler explanation. Regardless of the amount of light that gets through, some must get through because they can see what's on the other side. See where bee wants to go - > try to go there has worked over bee evolutionary history until very very recently (those pesky humans putting up all these force fields). Without the ability to understand that seeing something but not being able to get there is an actual result of the permanent glass and not just some transient obstacle that flying a bit more might get around is likely outside of a bee/wasp/etc's cognitive ability. If there were certain colors of glass that a bee encountered over and over that made it unable to get a reward I wouldn't be surprised if it could learn to ignore/avoid those... but it would have to be something conditioned, not innate. see the color learning blurb in the wikipedia: _URL_2_
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Probably because bees are attracted to bright coloured flowers, therefore also attracted the bright colours of the plastic.
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in the EU, all food must be labelled with its energy value in kJ, numbers of nutrients per 100 grams, and an ingredients list. However, all alcohol is exempt. Why?
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Alcohol isn’t a food and you don’t consume it for nutrition at all. I’m not sure what it’s technically classified or controlled under but it’s generally a separate agency or set of rules.
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Alcoholic drinks are regulated by the ATF rather than the FDA, so they don't require the same labels.
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If heat rises, why is it so cold in the mountains?
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Most heat is created when the sun's radiation contacts the Earth's surface, and then the heat rises. But as it rises, it also spreads out, and as gasses spread out they cool down because there is less activity in a specific space. So up on top of a mountain, the air is much thinner and pressure is lower, so there is less "air" to be hot. Also, if the ground is covered in snow it reflects sunlight and heats up much more slowly.
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> Why is it colder at higher altitudes even though hot air rises? Hot air rises, but as it does so it spreads out and by spreading out it cools down again.
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How can two companies with the same name [brand name] be owned by different people without trademark infringement etc?
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Most of the examples you cite are because *the two companies agreed in writing* to share the use of the name. Other examples happen because the companies are in different industries, such as Microsoft Excel software vs. Hyundai Excel automobiles -- the law says these are not "confusingly similar" since the products are so unrelated.
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I'm not sure about your specific example, but I do know that the US company “Burger King” is called “Hungry Jack's” in Australia, because of one single shop owner in Australia whose restaurant is called Burger King. He didn't want to lose his intellectual property, so he sued BK and won. Thus, it's “Hungry Jack's” Down Under.
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How is the news anchor always making eye contact with viewer, no matter which angle we sit?
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It’s a 2D image, so regardless of where you sit you’ll always have the same perspective on the newscaster.
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During interviews a person next to the camera is asking questions so that’s who they answer to, even not in interviews they are usually directing they’re speech to a person near the camera, not only does it help to make them speak and feel more natural, it also comes off as more natural to the viewer. Imagine how it feels during a news broadcast when the anchor speaks to the lens, there is something palpable when a person is “broadcasting” to a camera as opposed to speaking to another person, the lack of interpersonal connection is easy to notice and would make a documentary much less engaging
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Why do dogs love hanging their heads out the window?
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As air moves over the olfactory membrane, odor molecules settle on the scent receptors and get recognized. The more air there is flowing over the membrane, the more scents the dogs can detect. So when a dog sticks its head out the window, it’s like pigging out at a hi-definition all-you-can-smell scent buffet
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I actually looked this up just the other day. So, without verifying what I am about to say, I will say it. There are several explanations as to why dogs tilt their heads, one being that because of their superior hearing, they can better pinpoint the origin of a sound if they tilt their head because there is a slight delay in when the sound hits the dogs two separate ears. This tilting has been hypothesized to change the way sound enters both ears, allowing the dog to better understand what it is hearing. ...I... Actually completely forgot the other scientific reasons after typing that marginally-involved reply. But, one possible reason why they tilt their heads *so damn much* is because they realize we think it's cute as fuck.
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When I was a kid cartoons often depicted peeling potatoes as a punishment in the military. Was this pop culture image rooted in reality?
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The punishment for relatively minor offenses (often referred to as non-judicial punishment, or NJP) in the military is often extra duty (iaw DA PAM 27-10 CH 3-16(a)). Often this can include KP (kitchen patrol) duty. So an easy way to depict this duty as an undesirable task is peeling potatoes.
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It's not something they were raised with as a part of their culture. It's as foreign to them as something like stinky tofu or chicken feet are to those of us raised in a more Western culture.
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What are the spasms your body makes right as you are falling asleep?
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The cause of this is as your body falls asleep your brain wont receive any messages from a muscle so it sends a strong message to check if things are still responsive causing a violent jerk
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It's called a hypnic jerk. The best explanation found so far is that it is a holdover from our primitive ancestors, before our more monkey like ancestors left the trees. As you fall asleep, your muscles relax and higher order thinking processes slow. Your more primitive processes feel your relaxation and make you jerk to alertness, before you would have fallen from a branch
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What would happen to my body if I was put in 0 Kelvin for a fraction of a second - like 1 billionth of a second?
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Nothing interesting. Temperature differences matter, but so does heat transfer. Being teleported into pure vacuum (with no CMB) would still take several hours to kill you without insulation (assuming a pressure suit and air). Being teleported into a tub of ~0 K liquid helium would kill you within a second or two, but if you're only there for such a small fraction of time, you'll be okay.
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Yes. Every chemical process has an optimal temperature range to work at, including those in the body. At low temperatures the enzymes, chemical reactions, ion channels and active transport mechanisms will all slow down. Therefore your theory is correct.
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Why didn't the US experience hyperinflation that many economists and politicians said was going to happen when the FED did its quantitative easing during the Great Recession?
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There is no widely-agreed-upon answer to this. Economists have been stumped about this whole post-recession environment. Economic growth was slow, then it sped up, but that didn't improve wages, workforce participation is still low, we are past-due for another major market correction. This is a very strange-looking recovery. The struggle that the Federal Reserve has had to keep inflation up is rather mysterious. Aside from the political infeasibility of your hypothetical and the difficult-to-predict wage-warping effects that such a program would have, it's not clear how much government spending would actually cause significant inflation. Some economic models would predict quite a lot while others would predict very little. Regardless, a government program of that sort would have to be *extremely* expensive to risk having a large direct impact on inflation.
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The .com bubble popped and that led into a recession. A devastating terrorist attack certainly did not help.
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Why are there different scents to the time of day? Like morning has its own smell along with the evening
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I used to live near an industrial sized bread bakery/manufacturer. Every night would smell like freshly baked bread. Perhaps you are getting smells from different businesses nearby which work on different schedules. Perhaps not something as recognizable as bread.
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Sensory adaptation. you're surrounded by the smell so your receptors just ignore it Kind of like how Farms smell really bad to city folk but people who live on farms don't smell anything
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How did the whole 'open a locked door with a credit card' trope come to exist?
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Because with a cheap lock, you can do it. _URL_0_ It's now become completely overused in media, but with a cheap lock, the locking mechanism only makes it so you can't turn the handle. If that's the case, and if you can fit the credit card inbetween the door, there's a chance you can reach the bolt and actually push it in, especially if it has a slant (as you can with a finger. Open the door, lock it, and try it). Of course, if the actual bolt is only brought in with a key, or you have a deadbolt, the credit card method will not work.
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Actually this was an issue with credit cards, that debit cards fixed, as a legacy of an older era where security of credit cards was less important. As of now, most credit cards around the world are transition (or already have transitioned) to credit cards being chip and pin.
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No wrong answer penalty on SAT?
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Before the guessing penalty was modified/removed, every wrong answer carried a 0.25 (or similar) point penalty (in addition to not earning points on a wrong/blank response). Because questions had 5 answer choices, random guessing would yield no net benefit versus not answering a question where no choices could be eliminated. With the new changes, a wrong answer and a blank response are scored the same, so random guessing any unanswered question is advantageous.
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The penalty was decided, and it didn't include forfeiting the games. That would, presumably, be too much of a penalty, according to the commissioner. The penalty process in the NFL is quite subjective.
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How did the USA become one nation?
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During the American Revolution and in its immediate aftermath, the former colonies were organized under the Articles of Confederation, which did indeed give most of the power to state governments rather than a central federal government. This caused a lot of problems, chief of which was that the federal government could not compel the state governments to give them money to pay the soldiers who had fought in the war. The problems with the Articles of Confederation prompted the drafting and ratification of the US Constitution, which created the United States of America as we know it today, with a federal government sharing power with state governments (although nowadays, the federal government definitely has the lion's share of the power).
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How did it govern itself? How socialistic was it, really?
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What is Juniper and why is everyone freaking out because it has a back door?
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Juniper is a hardware manufacturer that makes networking equipment. The internet relies on equipment like this to function. A backdoor is an intentional hole in a security system that allows someone to get in when they shouldn't be able to. Think of a robber slipping in the backdoor of your house because you never lock it. Juniper announced that it found a backdoor into its systems that it didn't place there. To continue my analogy above, imagine one day you found a new door into your house that you never knew existed, and that you don't even have a key for. There is speculation that the NSA was responsible for putting this backdoor into Juniper's system, but nothing concrete yet.
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Juniper trees are not a pine tree. Pine nuts are the seeds of various members of family Pinaceae, genus Pinus. Junipers are family Cuppresaceace, genus Juniperus. Junipers are cross allergenic with cypress, and presumably other members of Cupprasaceace, but not with Pinus.
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When game companies are bringing down their servers for maintenance, what are they doing?
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They could be doing any number of things from implementing security fixes to adding new features to the game or updating UI. There is a great number of things they could be doing. However, when servers are brought down, it's because it's usually required for them to end all data transmissions when editing files. It's the same concept as trying to delete a file you have open on your computer. If you create a Word document and open it up, then try to delete it without closing Word, the computer won't let you delete the file. It's the same thing for those companies. They have to make sure nobody is accessing those files when they go to edit, move, or delete them.
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A server is just a computer. Sometimes computers need to be updated, or restarted or just generally other things that are not conducive to them running your games 24/7. If there is something significant that needs to be done that will affect all or most of those computers, sometimes it it just easiest to take them all offline at the same time during a period of low traffic, make the update and then put them back online.
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If a giant globe of ice (moon sized, let's say) had a chute cut down at an angle through its midsection, could you slide all the way through, or would gravity stop you at its center?
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You would slide all the way through. If the ice was perfectly symmetrical, the gravitational force you would experience in the middle is zero, so you would speed up for the first half, then slow down for the second half.
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[It would spread out in a sphere](_URL_0_) The lack of gravity allows it to spread out rather than fight its force.
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Jerusalem has Jewish, Christian, Muslim, and Armenian quarters. Why Armenian?
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I’d also like info on the now gone Moroccan quarter(?), why was Morocco (in addition to Armenia) so prominent in the Old City?
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First search result when I typed "gaza" _URL_0_
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Are there any scientists actively working on theoretical space ships?
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Yes. _URL_0_ EDIT: "All NASA support to sustain cognizance on these possibilities has been withdrawn as of October 1, 2008." Dang, now I am sad.
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This theory was put forward in 2003 by Peter Lynds. This has been dismissed by mainstream physicists for the lack of a mathematical model behind its philosophical considerations. There's more info [here](_URL_0_)
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How do noise-cancelling headphones work?
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There is a small microphone on the outside that monitors the noise, this is connected to the speaker within the actual headphones. This microphone takes in the outside noise (e.g. the car engine) and plays 'anti-noise' ( this is the opposite of the 'car engine') through the speakers along with whatever you are actually listening to. This has the effect of 'cancelling out the noise' that has permeated through the earcups. I hope this helps and if you're asking this because you're thinking of buying them I can assure you they do work! If my description is rubbish here you go, _URL_0_
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Oh I see the confusion. The sound isn't created by the computer. The earbuds convert electricity to music. The computer outputs electricity that looks like the sound. The earbuds have a "voice coil" which is a coil of wire which floats inside a magnet. It looks like [this:](_URL_0_). The coil will move in and out because electricity flowing through a coil creates magnetism which will fight with the regular magnet that the coil is floating around. The coil has a little speaker cone at the end of it which pushes the air to make the sound. TLDR: there's electricity in the wires, not sound.
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How do noise-cancelling headphones work?
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They emit frequencies of the opposite wavelength to negate noise other than those they are emitting.
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Oh I see the confusion. The sound isn't created by the computer. The earbuds convert electricity to music. The computer outputs electricity that looks like the sound. The earbuds have a "voice coil" which is a coil of wire which floats inside a magnet. It looks like [this:](_URL_0_). The coil will move in and out because electricity flowing through a coil creates magnetism which will fight with the regular magnet that the coil is floating around. The coil has a little speaker cone at the end of it which pushes the air to make the sound. TLDR: there's electricity in the wires, not sound.
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Why do electrical circuits ALWAYS have a negative side? Why doesn't a lamp just "suck" all the electricity from the positive side?
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For much the same reason that a waterwheel or hydroelectric dam also has a lower side and a higher side.
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It's similar to water always "knowing" to flow in a downward direction. Electricity flows in the path of least resistance.
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Why do minor chords sound sad?
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Keyboardist / novice producer here. They don't always sound sad. It's in the way they are played. If you play them slowly, with pauses and expression, they can sound sad (cough cough Adele). If you play them rhythmically, they can sound (and excuse me for bringing it back to 2005 here) "epic" (_URL_0_) or even celebratory. (_URL_1_). It's all in how the music is played. I suppose that is related to speech patterns, people often talk more slowly and with greater expression when they're conveying something sad. In addition different series of chords, (chord progressions) can seem mellowing, uplifting, inspirational, happy, or sad. I can't explain why that is, only that many musicians simply have an ear for the type of mood they want to convey.
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As was explained to me by my master's of music education girlfriend (so I will claim absolutely no expertise) the whole major cord = happy minor cord = sad thing is cultural artifact, not something inherent to the tones. It's why music which predates the western tradition seem very strange, unsettling, and alien.
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What happens in the engine if you put diesel in a petrol car?
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If you have some petrol in your car and put diesel in it, it will start but smoke heavily through the exhaust. Damage will not be great to the engine though. However, if you fill in an empty tank of a petrol car with diesel fuel it will never start. If you've ever compared gasoline to diesel fuel, you know that they smell different. They also feel different -- diesel fuel is oily. Like oil, diesel fuel doesn't evaporate like gasoline does. Plus, diesel fuel is heavier. A gallon of diesel is about a pound heavier than a gallon of gasoline. There is the requested summary of what's happening in the engine: The fuel injectors in your engine would inject the diesel fuel into the engine's cylinders. The spark plugs would fire, but nothing would happen after that. Because the diesel fuel doesn't evaporate very well, the spark plugs would have nothing to ignite, and the engine would never start.
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a diesel engine running on gasoline will ignite the fuel in the cylinders to early, most likely destroying the engine. a gasoline engine running with diesel will not run at all, the spark plugs (and the valves, the injection pump and some other parts) will become oiled and sooted. you need to flush the engine with cleaner (or gasoline) to make it work again.
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Why does sodium chloride dissolves in water but not in ethanol, when both are polar compounds?
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NaCl does dissolve in ethanol, just not very much. Water is far more polar and and the small molecular size would allow for more interactions with Na+ and Cl-. With more ions being supported by the solvent, more ions can be accepted/dissolved in the sovlent, and so salt has a higher solubility in water than ethanol.
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This image could help clarify: _URL_0_ When you dissolve NaCl, the anion/cation are being stabilized by the polar water molecule. When you say "properties of Cl" you are most likely referring to Cl2. Cl without charge would be a Cl radical, and highly reactive. Cl2 is not a polar because it consists of a pair of the same atom, so there is no partial positive or partial negative. Since it is not polar, it will not interact as favorably with water or with itself, so it won't take much energy to make it evaporate. You can neutralize sodium by adding electrons - for example, in an electrollytic cell. Sodium is a metal that (in ways I do not undesrstand) is capable of packing into a solid in which the electrons are delocalized over the whole lattice.
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Why can't you feel it when you're on a commerical flight and the airplane makes a turn that is practically perpendicular to the ground?
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When you're in a turning vehicle, "centrifugal force" (*) tends to push you toward the outside of the turn. At the same time, gravity pushes you downward, so the total force on you is down and outward, on a diagonal. When a pilot makes a "coordinated turn", he/she tilts the plane to an angle that matches the direction of this diagonal force, so it pushes you straight down into your seat rather than sideways. As a result, you'll feel a bit heavier during the turn, but you won't be pushed to the right or left. (*) Centrifugal force is not a real force, but it's a useful way of understanding this at the ELI5 level. The explanation would be twice as long without it, but would end up at the same conclusion: the tilt of the plane ensures that the force on you is aligned with your seat.
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The same reason that when you're in the middle of a flight on an airplane, you can get up and walk around with no problem. We don't feel our speed, we feel *changes* to our speed - it's at takeoff, when you and the plane are accelerating, that you're being pushed back in your seat.
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Is it possible for the body to retrieve water from urine after it has been filtered by the kidney?
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The cells that line the urinary tract are impermeable. This is important otherwise you'd risk urine leaking back into your body. As a result, they are also impermeable to water. So, to answer your question, the body cannot retrieve water from stored urine.
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Your body is incapable of absorbing any more water from the urine once it has left the kidneys. The epithelial cells lining these areas are not permeable to water and they need to be this way to function properly. If they allowed water to pass then they would leak water back into the body (especially when the urine was dilute) which is the exact opposite of what the kidneys are trying to do. If these cells were water permeable it would actually make you more dehydrated. This is because through osmosis water moves from an area of high concentration to an area of low concentration. If you were dehydrated your urine would have a very low concentration of water. This would be lower than it was in the rest of the body which means you would actually be losing water due to it diffusing into the urine in the bladder
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What is the difference between stockings, pantyhose, and tights?
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[Stockings](_URL_1_) require a belt and suspenders to hold them up. [Pantyhose (called tights in the UK)](_URL_3_) go all the way up to the waist. I understand some people see them as underwear in their own right (hence the "panty" bit of pantyhose, but there is some contention. [Tights ](_URL_2_)are what pantyhose are called in the UK, but it seems that the term tights in the US means thicker, or coloured pantyhose. Something that might not be so transparent and sexy. Less formal. Then there are [holdups](_URL_0_) which are like stockings but without the belt, they are usually elasticated at the top, or with a strip of grippy stuff that stops it from falling down from the thighs.
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It's called a garter. Back in the day, stockings used to be made kind of like high socks, so girls would wear a garter on their thighs to hold them up (like suspenders for socks). Now stockings and socks are made with elastic tops so they stay up on their own, but sometimes girls will still wear a garter because it's considered old fashioned sexy
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How do you differentiate east from west at the poles?
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Exactly at the poles, there is no east or west. From the south pole, every direction is north. Close to the poles, east and west still exist; that latitude band is just a really small circle
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Because there's a North and South Pole, but no East or West Pole. So there's no points of reference to determine when you stop going East and start going West, but there is for North/South movement. More geography than maths, tbh
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What work is currently being done in terminal ballistic modeling? Right now the tate equations seem to be the best but still very far off from a universal analytical formula.
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I am not familiar with the Tate formula although I am an aeronautical engineer which is includes studying ballistics. What a lot of people fail to realize is that real life is nonlinear. Creating a universal analytical formula for a non linear phenomenon is pretty much impossible. Take the Navier stokes equations for example. If you could solve them in their full form you could describe flow at any point, but they have yet to be solved. That’s why we use linear equations to model sections of non linear phenomena which can only be used in that section, not universally. Might not be the technically savvy answer you were looking for but I hope that helps!
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Ab initio methods, effective field theories, lattice field theories, mean field/Hartree-Fock, configuration interaction/shell model, cluster expansion, density functional theory, phenomenology, etc.
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How does stress manifest as physical symptoms?
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So stress is a catch all term for all things that impact ones life, good and bad. These things make you brain go into over drive and produce more chemicals than it normally would. Sometimes the brain produces more chemicals than it needs or can use. These chemicals and this brain power is also part of what regulates all body functions. That being said stress from bad situations such as fear also makes your brain tell your body weird stuff. Sometimes it can pull most of your blood to your core making your fingers fold but your torso sweaty. Or it can tell you to be ready to run when there’s nothing to run from making you feel extra sleepy all the time while being too on edge to sleep.
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Physical pain can cause a dramatic increase in blood pressure from the stress, which could cause a heart attack. Is this what you mean?
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Why is that for some people drinking coffee makes them wide awake for quite some time but for others it makes them tired?
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The caffeine in coffee stimulates neurotransmitters that have to do with alrtness. It is possible to overstimulate and drain these neurotransmitters. So if you are drinking lots of coffee and energy drinks, that can happen. Also for some people who have very "hyper" or "scattered" or "trouble focusing" brains (aka ADD) the stimulus from caffeine can actually help the "focus" of the brain, and it is very relaxing and even restful.
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Because that's not the same kind of energy. A calorie is a unit of energy our body stores and uses, caffeine is just a chemical that wakes us up.
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Is it possible to refract radio waves at such a series of angles, that you end up with visible light?
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No. Two issues: 1. When entering a material with a different refractive index, the wavelength does change, but not the frequency. Radio waves stay radio. Visible, visible. 2. The refraction angle affects nothing.
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Radio waves aren't a form of visible light, rather light and radio waves are both forms of Electromagnetic Radiation, determined by frequency and wavelength. It's like saying cars and trucks are both vehicles, but trucks aren't a form of car, and while a car will fit in my garage, a truck won't due to it's different properties.
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If the moon disappeared, would the earth change its orbit around the sun?
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Earth's orbit around the sun would be almost totally unaffected. This is because an orbit around the sun does not depend on the mass of the planet, or the combined mass of the planet and its moon(s), as long as the mass of the planet is much smaller than the mass of sun, which it is for all planets. Earth and Moon orbit their common centre of mass. The centre of mass is inside Earth and the orbital speed of Earth relative to that point is about 10 m/s. Earth would still have this velocity if you magically make the Moon disappear. Like when a hammer thrower suddenly lets go of the hammer, the hammer keeps on going in the direction it was moving. But since this velocity is only about 10 m/s, adding that to Earth's normal orbital velocity around the sun, about 30 km/s, makes hardly any difference. Earth's orbital velocity around the sun already varies about 1 km/s depending on the time of the year due to the eccentricity of Earth's orbit.
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You raise an interesting point. The Moon should have no problem being in orbit around the Earth. But.. There may be a relatively minor (I would imagine) change in its orbit depending on the orientation of the Earth-Moon system with respect to the Sun. For, example, the Moon may feel the effect of the missing Sun up to 1.3 seconds before or after the Earth. This will have an effect, but it will be very brief. The Earth travels around its orbit at 30 km/s (and by extension so does the Moon to a good approximation). Which means that at most (this is very approximate) the distance between the two object at the moment the Sun's effects disappear will change by around plus or minus 39 km. The lunar distance to Earth normally changes by 42,800 km from its closest to farthest points. So, I think, the difference may not even be measurable by our instruments.
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If an American astronaut smoked weed on the international space station, could he be prosecuted? Would it make a difference in which state he left earth from?
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There's actually [an agreement](_URL_0_) that all counties laws are in effect within each countries modules. And Federal Laws are superior to State Laws so marijuana is still not technically legal in 'legalized states' so yes, they could be prosecuted for 420. However, those charges would be ancillary to the charges brought against them for endangering their fellow astronauts by: 1.) Lighting a fire in a space station 2.) Operating a space station while intoxicated
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> Is the ISS considered the territory of any particular sovereign state? [Each module in the ISS is considered the territory of the country that provided it, and under the jurisdiction of that country](_URL_0_). So if you're in a US module then US Law applies, same thing with Russia, or Canada, or any of the other member countries. & nbsp; > What laws do ISS astronauts follow? Apart from the various national laws, Astronauts are subject to the policies and procedures of their parent organizations (e.g. NASA, Russian Space Agency, etc.) & nbsp; > Would various petty crimes technically be legal aboard space stations? There are differences in the laws of the various countries, but nothing that would make any crime of significance legal.
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How did the hologram protests in Spain work?
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No, they did not use a satellite. There are projectors nearby, which project the "hologram" onto a canvas. The canvas has lot's of holes in it, so you can see through, but is dense enough so you can see the projection
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> Saw a demonstration of television last Saturday. Very vague & flickering. - H. P. Lovecraft to Robert E. Howard, 25 Oct 1933, A Means to Freedom 2.654 > Saw a demonstration of television the other day at a local department store. Rather like the blurred, flickering biograph films of 1898. - H. P. Lovecraft to August Derleth, October 1933, Essential Solitude 2.612 What Lovecraft saw was a demonstration of the [Sanabria Mechanical Television System](_URL_8_). This was well before television was a household appliance - it was basically a novelty, dragged out at sideshows and demonstrated to crowds that still primarily went to theaters, nickelodeons, and silent films.
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Are there any biological advantages to being overweight? Could it allow you to survive longer without food?
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That is the advantage, yes. Scientists believe the reason why humans evolved to store excess food as fat is that it allowed people to survive times of famine easier by having reserve energy. The issue is that our bodies were optimized for lifestyles where the idea of having plenty to eat all year round wasn't possible.
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No, the body does not reach a point of "that is enough". If you consume more than you expend then you gain weight. There is no evolutionary pressure to prevent getting obese because for most of human history food was not often in enough abundance for people to be obese enough that they were not able to reproduce.
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What is the function of a World Trade Center?
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The world Trade Center association exists to promote exchange between corporations and governments internationally.
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The World Trade Center rented floor space to other companies. After 9/11 those companies would've set up their offices in some other building. The specifics will be different for each company.
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