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How sites like The Pirate Bay are illegal but find ways to stay up and even fight the cases brought against them? | The reason is that they do not host illegal files. They index them which puts them in the same grey area as search engines like Google and Bing. In fact, the pirate bay doesn't even host the torrent files, they provide magnet links. When they fail to respond to DMCA and other copyright takedown requests is when torrent sites get in hot water. | Because the sites themselves aren't hosting any illegal content. They're just linking to it. |
Can coral bleaching be reversed? | Yes, and [actually they can come back from near-dead](_URL_1_) (90% bleached) in just a few years... But that requires that the underlying stressor go away and stay away. Unfortunately, we don't have the ability to directly control [most of what stresses corals](_URL_0_) (usually temperature, but also changes in light, salinity, pH, other chemicals present, etc) across large enough areas to make a difference. | Coral polyps have a symbiotic relationship with algae-like cells called dinoflagellates (also known as zoozanthallae) that live inside the coral polyp itself. The zoozanthallae can photosynthesise and generate energy for the coral to live. Coral is very fussy about temperature, salt levels and small silt particles in the water and need these to be within pretty strict limits to survive. Small changes in temperature can cause the coral to expel the zoozanthallae and die.....this is coral bleaching. |
How can sperm survive for days in the heat of a woman's body, when it needs to be outside of the man's body(in the testicles) to survive? | I believe the lower temperature of the testes is optimal for spermatogenesis (sperm development) but that the little dudes (once fully mature) are fine at body temperature. | Your body just deconstrukt them. Your balls can never get *full* The amount of sperm leaving your body has nothing to do how long you **saved** up. I for example only had a few wet dreams in my life. |
Why do off-brand foods taste so different than brand foods of simple (one ingredient) items, i.e. grated parmesan cheese? | Cheese is probably a horrible example when you're looking at "identical" products. The type of milk used, how concentrated the milk gets, how it's processed, how it's aged, how long it's aged, etc *all* make a huge difference when looking at the taste & quality of the final product. If you go to the grocery store, there is a *huge* gap in price between cheap domestic parmesan cheese & the high-quality, aged, imported stuff. If you want to compare apples to apples, try looking at a product that actually is simple - like oatmeal. | I think it has to do with the different techniques used to make the cheese, i.e. different conditions under which the milk is fermented. Also different types of milk, from say different breeds of cows, probably do taste slightly different. |
Haiti was the second independent state in the Americas. Why has its development been so lousy compared to its neighbors? | A great book that talks about Haiti is called "Moutains Beyond Mountains", about doctor Paul Farmers' attempt to progress Haiti into the 20th century (or even the 19th century) in terms of medical attention. Haiti's atrocious public health has played a huge role in their complete lack of development, and one of the reasons for this was due to a cultural mistrust for doctors and misunderstanding of modern medicine. The book is extremely interesting and informative about how the culture of Haitian Vodou essentially enabled massive outbreaks of easily curable diseases to cripple Haitian society. The book is not accusatory towards Vodou or anything like that, but it explained how when there was an outbreak of cholera or something, it was chalked up as an act of God, and therefore attempts to quell the outbreak were usually completely absent. When you have no public health, progressing as a society is almost impossible. | Niall Fergusson addressed this in [The West and the Rest](_URL_0_) I believe one of his conclusions was that property rights and English governance was better suited towards productivity than the centralized South American system. |
Why does spicy not have a distinct flavor to me; like sweet, or salty? | Spicy is not a flavor, rather it is a feeling of pain which occurs when the capsaicin stimulates the nocioceptors in your mouth. Your tongue has the receptors to identify 5 distinct flavors: sweet, salty, sour, bitter, and umami. | There are no tastebuds on your tongue for spicy foods unlike sweet or salty. Spicy is the reaction of nerves in your mouth to capsaicin which makes stuff spicy. The nerves in your mouth are there to react to heat, knowing when stuff is too hot to eat. These nerves react to capsaicin in the same way. Basicly these nerves send out the information that the food in your mouth is too hot to eat when eating capsaicin. That is why it actually feels really hot in your mouth. |
Why were the Revolutions of 1848 a failure? | Depends on how you frame it. On the one hand it was absolutely successful because it *really* brought the point of the revolutions to the forefront for a number of countries (or at least regions)- France, Germany, Poland, Italy, and the Austrian Empire. Nationalism in a number of these countries would play critical roles in setting up both of the world wars. On the other hand the revolution in itself was swallowed within a year, and for the tens of thousands of deaths across Europe only secured an end to absolute monarchy in Denmark, an end to the serf system in Austria / Hungary, and brought a (final) end to the Capetian monarchy in France. To be blunt, while the point of the revolution was largely unrealized, it's message was powerful. | Full overthrow of society revolutions are often so chaotic that authoritarian governments are the only thing that can keep the peace. It's never a simple us V them there are dozens of factions vying for power. |
What would happen if a living brain was exposed to light? | The brain has no melanin, so it wouldn't get a tan. As to the effects, I can't imagine UV radiation having a terrific effect on it. It has no natural defenses to it, the way your skin does (see the aforementioned melanin). I'm betting you're looking at cancer, one way or another. | Light absorption follows a simple Lambert-Beer Law in tissue, meaning the output intensity can be made arbitrarily high by increasing the input intensity. Using a wavelength in the Optical Window would decrease the absorption coefficient, helping this. As to whether this would be harmful...there would be some/a lot of heat transfer. I would guess that you could do it for a brief period of time, but any longer than a few seconds would cause tissue death. _URL_0_ |
Why do a lot of arranged marriages work out when the partners don't know each other to begin with? | Long-term relationships have a lot less to do with initial infatuation and attraction, and far more to do with mutual respect and how much effort you put into the relationship. Also, I have a couple of friends who had "arranged" marriages. Neither of them were forced into it. Their parents just did the initial searching and filtering. They still got to meet the person in advance and they decided together with their parents whether it was a good fit or not - obviously there'd have to be some attraction. | So I am from India, where arranged marriages are still common. Arranged matches are set up not just by immediate family but by extended family. In many societies (including Indian) extended family goes upto 2nd or 3rd cousins. It's almost impossible to not to have that sort of thing. An exception can be an orphan who grew up with no family etc. In that case, people around you (neighbors etc) take up the role of surrogate parents and arrange the match. I get it. it's not an answer from a "historical" perspective but more of real life experience. |
Why do the Scottish want independence? | In addition, I would point out that it's not the Scottish people themselves pushing for independence, but the ruling SNP party - Nearly all public surveys on the subject show the Scottish people are generally in favour of the union: source: _URL_0_ | Please help me understand why this vote is occurring in the first place? Why would the Scottish people want to separate from the UK? |
Why is gun control so controversial? | Guns are a symbol of power. Most people want the nice/good guy to have more power than the bad guy, but bad guys don't listen to rules. By making a rule that no one can use guns, the good guy won't have a gun, while the bad guy does. The only way to make sure the bad guys don't have power, is to allow the good guys to have it too. On the other hand, guns are tools for killing people. There is very little use for a gun other than to hurt something. If anyone can have a gun (even people who don't know how to use them), many people will have accidents and hurt others even if they don't mean to. The last possibility is to only allow certain people to have guns. We can try to pick out the good guys and allow them to have guns, but it would be a lot of work, possible discrimination, and there would still be less good guys with guns than bad guys with guns. | The victims family's of mass shootings want someone to pay. They see gun manufactures in being complicit in these shootings. I'm sure some has to do with the fact that in all the parties involved they're the ones that have money to go after. Edit: Also, Protection of Lawful Commerce in Arms Act prevents in most cases legal action against manufactures and dealers. So, even though they want to most can't. |
Where is a good place to find reviews of history books? | If you have jstor or lexus nexus or any type of online subscription like that (your library will) just search the book title and review. Example 'Avrahm Yarmolinsky The Road to Revolution review' and itll likely come up with many reviews. | A good history book is: * Well researched and well written * Clearly places itself in respect to existing literature on the topic. * Uses primary sources to create an engaging narrative. * Is well grounded in historical theory(ies). * Has a strong introduction and conclusion which make the scholar's point and argument in brief. A bad history book: * Overgeneralizes * Makes claims that it can not back up with evidence. * Is poorly sourced/doesn't have clear footnotes or endnotes throughout. (This is the biggest one, and is a feature of a lot of pop history. If a book has poor notes, I won't bother reading it). * Does not seem to understand the historiography of the topic. |
Since the earth has a magnetic field why can't we use magnets/electromagnets to make floating cars and structures? | Theoretically, you could. However, the magnetic field strength of the earth is extremely weak, somewhere in the range of 20 to 60 millionths of a [Tesla](_URL_0_ , which is negligible for the applications you are considering, such as levitating large masses. Basically, the gravitational force of the Earth pulling inwards on masses overcomes the magnetic attraction/repulsion *very* easily. | It's not the earth's magnetic field that make magnets work. You're thinking of compasses. Compasses won't necessarily work in space, depending on how far out you are. Though the earth's magnetic field does extend further than you might think - about a quarter of the way to the moon. Here's NASA's answer to your question: _URL_0_ |
What kind of slave owner was George Washington? | Washington was in a battle between human rights and slavery. Perhaps this may help give a perspective: "I never wish my people to work when they are really sick, or unfit for; on the contrary, that all necessary care should be taken of them when they are so; but if you do not examine into their complaints, they will lay by when no more ails them, than ails those, who stick to their business, and are not complaining, from the fatigue and drowsiness which they feel as the effect of night walking, and other practices which unfit them for the duties of the day." He also stated: "It is not my wish, or desire, that my Negros should have an oz of meal more, nor less, than is sufficient to feed them plentifully." Source: Washington to Pearce, Philadelphia, May 18,1794. (ibid., 33:360,474) For further reading, you can check out George Washington and Slavery: A Documentary Portrayal by Fritz Hirschfeld. | I will say that numerous presidents owned slaves and employed them at the White House, essentially engaged in affairs related to managing the state. The most famous of which was [Paul Jennings](_URL_2_), who actually published his memoirs which you can read. There were also a number of slaves [involved in the building of said White House](_URL_0_)--and were most recently invoked in a speech by Obama--as well as [building the capitol itself](_URL_1_). (According to the Pulitzer Prize winning Politfact: "The records reflect 385 payments between 1795 and 1801 for "Negro hire," a euphemism for the yearly rental of slaves. " So while I cannot say if the government itself directly owned slaves, they did regularly pay for their labor and employ them not just in service of the government but to literally build it. |
How do random glitches happen on computers and smart phones when the code is perfectly fine? | They happen because the code is never perfectly fine. There are errors in any software. The code just mostly works, while in a stable situation. Once in a while something unexpected happens - like a network loss, or a hardware problem, or some weird user input - and the software might not be ready for this kind of scenario. This is when you see a glitch. | Imagine you have a machine that reads a ribbon of symbols and follows an instruction based on those symbols, such as "advance one step", "rewind 3 steps", or "stop". Now imagine some kind of glitch occurs and the machine finds itself unable to continue acting the way it's supposed to due to getting the wrong symbols in the wrong places. It's easier to correct this by resetting the machine than it is to figure out which step the error pictures in and going back to that step. The same is true of computers. If they're stuck in the wrong mode, resting it starts you back at the begining and this time maybe the glitch won't occur. |
do planes have to keep tilting down for long flights to make up for the earth's curvature? | No. Gravity is pulling them down while the lift from the wings is pushing them up. They stay at a constant height above the surface of the planet. | It does. There are global wind patterns caused by the Earth's rotation. |
Why do we feel all the major emotions like love/anger/grief/hurt/etc. in our chest? | Strong emotions are accompanied by a heightened heart rate. In the case of emotions like fear, pain, anxiety, etc, this is to pump extra blood to your muscles in case you need to fight or flee. With love, a large amount of oxytocin is released, and that particular hormone has the affect of of raising your heart rate; I have no clue what the purpose of that reaction is, or even if its significant. As for grief, I cannot say. Edit: so a lot of people have left responses either correcting me, or giving far more detailed explanation. Thank you. I really have no authority on this; I have no extended education In biology. I'm just someone who did a little quick reading, combined it with some speculation, and tried to explain my thinking clearly. As a throwaway account (not sure why that's necessary... ) pointed out, my answer is apparently wrong and/or way to simplified; make sure to read that response for a way more detailed answer | We don't actually know 100%, but the best theory seems to be that increased stress hormones cause some rapid changes to happen in the body. A wave of feedback floods the nervous system, raising heart rate, forcing the stomach and several 'less essential to immediate survival' organs to shut down. [The vagus nerve](_URL_0_) is a very large, complex network of pathways that wind all through the guts and chest. It appears to be a combination of the rapid change in heart rate, organ function and stimulation of the Vagus nerve that causes what our brain interprets as pain in the stomach/chest. |
How does sugar actually affect behavior? | When sugar enters the bloodstream and reaches the brain, it temporarily increases calming neurochemicals, such as serotonin.when the blood-sugar level is rise too high. The body responds by producing a large amount of insulin, a hormone that sweeps sugar out of the blood and into body cells. Blood-sugar levels may then drop so quickly, you may feel shaky or sluggish. Not surprisingly, low blood-sugar levels can trigger a craving for more sweets, which creates a vicious cycle of sugar highs and lows. If you tends to have postsugar meltdowns, you can prevent by tempering the amount he gets at any one time -- controlling portion size, diluting fruit juices, choosing treats low in sugar -- and by making sure he eats something heartier along with sweets. Protein (cheese, soy, beans, meat, nuts) and fiber (fruits, veggies, whole grains) help slow the rise and fall of blood-sugar levels. | Both are true. First the sugar provides you with energy. Then when it's used up you "crash," that is, you experience a sudden loss of energy (due partly to the excessive insulin your body put out to process all that sugar). That's why nutritionists recommend other foods that provide a more continuous supply of energy over a longer time. You don't get the "boom" but you avoid the "crash" after. |
How can a non-history major improve their casual study of history? | Read. Read what interests you. Find sources that make you sit down and keep reading. Become engaged with it, think about it. Learn the tools that Historians use to analyze and interpret. Find a specific area and repeat. | Someone who specializes in history could potentially find work at any museum or historical society. I live in the Chicago area and there are historical societies for practically every suburb around here, not to mention all the big name museums downtown. There are organizations like Daughters of the Revolution, _URL_0_, and others that are always looking for history majors. If you're particularly ambitious, the CIA might have a job for you. About 90% of what the CIA does is gather information about the politics and culture of other countries and regions and sell that information to people and businesses looking to expand their operations to foreign countries. And of course, you can be a teacher of history, which seems to be what most people think the majority of history majors do. This of course is just some of the options for a history grad. |
Radio antennas produce radios waves, is it possible to produce visible light waves this way? | In fact, visible light is produced by the (rapid) oscillations of electrons, which are oscillating inside some (smallish) material that acts as the antenna. > the antenna would need to be the same wavelength as the wavelength of the wave it is intended to produce. Is this correct? NO! This is not right at all. The wavelength of the light emitted by an antenna has to do with the ability of the electrons to resonate at that frequency. For example, visible light is often emitted by organic molecules that are much much smaller than the wavelength of light. | If by electromagnetic frequencies, you mean electromagnetic waves, then yes. Light is a type of electromagnetic wave, and reflects off mirrors easily, as do certain wavelengths of infra-red and ultra violet. Ouside of that, you can start to get troubles. The mirror can completely absorb some low energy radio waves (although depending on the mirror, the metal will reflect some), but will be completely ignored by gamma waves. To make gamma waves reflect, you require something much thicker than the average mirror, at least several metres thick. As for radio waves, long range radio works by reflecting the waves off the atmosphere and the sea so that it ricochets across the planet. |
What ARE 'primary colours'? Why can't I make them by mixing other colours? | Let's ignore the way tvs and computer monitors work and focus just on paint. Paint color is created by subtracting wavelengths from white. For instance, a rose is red because it absorbs green and blue wavelengths from the spectrum, and simply reflects red wavelengths. Because of the way difference molecules subtract different wavelengths, its very difficult to add wavelengths back in. When you mix a bunch of paint, each molecule is subtracting unique wavelengths away and all you're left with is a dark muddy black or brown. The only way to get back to a primary color is to add in so much white paint that it thins out all the other paints subtracting light. | Because red green and blue *are* the primary colours for lights. Pigments work differently and their primary colours are actually magenta, cyan, and yellow. Our eyes detect red light, green light, and blue light. However, if you have a strong red pigment (that absorbs all green and blue light) and mix it with a strong blue pigment (that absorbs all red and green light) you end up with black (since it now absorbs red, green, *and* blue light). That's why you use magenta pigment (which absorbs only green light, reflecting back the red and blue) and cyan pigment (which absorbs only red light, reflecting back the green and blue). When you mix magenta and cyan, the result absorbs green and red light, which means you get blue. |
Has evidence ever been discovered of ancient civilizations or prehistoric humans using a "sunblock" type of substance to prevent getting sunburns? | Early civilizations used a variety of plant products to help protect the skin from sun damage. For example, ancient Greeks used olive oil for this purpose, and ancient Egyptians used extracts of rice, jasmine, and lupine plants whose products are still used in skin care today.[19] Zinc oxide paste has also been popular for skin protection for thousands of years.[20][2 [wikipedia](_URL_0_) | Not my area of expertise: Consulting the sunscreen wiki page, I see that sunblock is specifically designed to protect you in the UV-A and UV-B spectrums defined as ~290-380nM wavelength light. See the chart here. _URL_0_ It will not protect you from other types of radiation such as that given off by Uranium or something. |
In the Movie Speed Racer The Mach 5 Can travel 3,806.0 mph. Would It be Possible to achieve this with Quantum Levitation? Or a Magnetic Track With a Mach 5 Engine? | I would suggest that any effort to apply science to the Speed Racer movie is not going to be fruitful in any kind of sensible way. | By matching its speed. Ever see a movie where someone runs up beside a train that is leaving the station, matches its speed, and then jumps inside? It's kind of like that, but a lot faster, and with rockets. |
Are brown dwarfs solid or gas? | Brown Dwarfs are essentially high mass gas giants (bigger than Jupiter) which fall just short of the mass necessary to sustain hydrogen fusion and become a star. So they're mostly gas, although there might be a solid core like what Jupiter is believed to have. | When a gas giant is large enough to maintain deuterium fusion in its core, it is a brown dwarf. |
Why do we need such precise clocks? | GPS is one example - GPS systems require extremely accurate timing to function. Radio waves travel extremely quickly, and a small error in timing translates to a large error in position. Each GPS satellite carries an atomic clock, and the GPS system even takes account of time dilation when making calculations - it has to, or the error (though miniscule) would quickly make the system unusable. The GPS time signal is so precise that it's often used in systems that have nothing to do with location finding but require an accurate time stamp. | Quartz clocks, use something called an electric oscillator, or crystal oscillator that is regulated by a Quartz crystal. Basically, the crystal, or piezoelectric material (a solid material which has accumulated electric charge due to mechanical stress), vibrates at a very specific frequency when in an electric field, which can be measured and use to keep time in an extremely accurate manner, as opposed to mechanical watches which uses a spring or sprocket to regulate time, which can lead to inaccuracies, due to expansion of the metals due to heat or cold and other factors. |
When we "feel" things while dreaming, are any nerves in our body active? | Your peripheral nerves only fire in response to external stimuli. So the short answer to your question is, no. Say you get poked in the leg in real life, while you are sleeping, your mechanoreceptors (receptors that perceive touch) will activate. This may or may not cause wakefulness depending on a large number of factors, such as your stage of sleep, your excitability, whether or not this sensation can be incorporated into your dream, etc. If you are poked in the leg in your dream, only your brain neurons will register this. The neurons that are ultimately responsible for that sensation in your brain (in your somatosensory cortex) will be activated, but mechanoreceptor activation is a one-way pathway, so activation that originates in the brain will not travel back to the periphery. | Your brain creates chemicals during sleep which stop nerve signals being sent to the body. This is why you (usually) don't actually move around when dreaming. Sleep paralysis happens when you wake up, but these chemicals haven't worn off yet. |
Why is marble such a good material for sculpting? | For a stone, it's soft enough to be carved with metal tools, but hard enough to retain detail. The best marbles for carving also have a very tight uniform grain structure, meaning you can get very fine true to life detail. Marble can also be polished pretty easily and is found in large easy to quarry veins. As far as natural materials go for statuary, it's pretty perfect. | Two reasons: 1) Marble is a relatively soft, porous surface, and the mineral crystals that water leaves behind can embed themselves physically in the surface. 2) Marble is composed primarily of calcium carbonate family minerals. Your typical municipal water supply will evaporate and leave calcium carbonate family minerals. The rings and the marble are chemically similar so you can't rely on cleaners that attack calcium deposits. That's why we use the silica-based granite for counters and high-traffic areas, it's much tougher and resistant to calcium stains. |
Why do so many rappers, including the ones which are fairly tall, have "Lil" prefixed to their names? | It actually has nothing to do with size. In gang circles, "Li'l" as a prefix is intended to be like "Jr." As a suffix. In the gang, you earn your name by putting in work. If somebody already has the name you are intended to be given, you will be "Li'l ___". Your gang name is going to be Monster? Well since there's already a Monster, you're going to be Monster Jr., or Li'l Monster. | Probably because that's how we constantly see them billed in movies and television. We've been conditioned by exposure to say their names like that. |
Is bruising gin a chemical reaction? | I couldn't find much other than hearsay, but [here](_URL_0_) is a StackExchange post that sheds some light on the situation. According to the top comment, "bruising" is largely due to aeration of the drink as well as mixing in chipped ice fragments which combine to change the overall flavor and mouthfeel of the drink. This seems to indicate that it's a purely physical change, but the post later mentions that the aeration of the drink causes accelerated oxidation of aldehyde molecules in the liquor which is responsible for the supposedly sharper flavor of "bruised" gin, indicating a chemical change. | It's actually a combination of trained reaction to pain (or should I say, non-reaction) as others have said, AND the fact that the gingiva (gum) surface is already relatively broken and compromised from where the baby teeth used to be. Less tissue damage occurs when an adult tooth emerges through a pre-existing socket, versus tearing through all layers of tissue in a previously uncompromised gum for a baby tooth. |
Why does it burn when I burp after drinking a carbonated drink and blow it out my nose? | Carbon dioxide is what make the bubbles in your fizzy beverages. It's also slightly acidic, so when you burp, you're getting slightly burned | Carbonated drinks contain dissolved carbon dioxide. Carbon dioxide naturally reacts with water (in the drink) to produce carbonic acid (a weak acid). Weak acids such as citric acid (lemon juice) or acetic acid (vinegar) have a sour taste, so carbonating drinks changes their taste along with giving them an interesting texture. If you guzzle down a soda the carbon dioxide bubbles collect in your stomach and eventually you burp up almost pure carbon dioxide. If you happen to exhale the burp through your nose then the carbon dioxide can react with the water on the surface of your nasal passage to form carbonic acid. Your nose is sensitive to things like acids to protect you from breathing in nasty things, so having an acid suddenly form on the inside of your nose sets off pain receptors and gives you an eye watering sensation. |
Do Animals Have A Sense of Rhythm? | Some do! Check out [this article](_URL_0_). This mentions parrots and elephants specifically, but sea lions and bonobos have also been found to keep a beat. There may be other examples. | I believe that is a tricky question. Elephants, dolphins and crows mourn their dead, and this behavior is probably also seen in other animals that I’m not aware. They are very clever animals though so they may be unique in that sense. Koko is also a gorilla who was taught sign language, and there was a video were when asked where her pet went she answered with sadness and what seemed like comprehension (I do not remember the actual “words” Koko used though). I believe it’s impossible to actually prove if they know know, but it seems possible for the most clever ones I guess. I’m sure someone else will answer better than me, but that’s what I know. |
Can two entangled particles both be in superposition? | Entanglement can be seen as a form of superposition. There are product states that are expressed as superpositions of basis states, but entangled states must be a form of superposition in a basis describing the subsystems. Measurement collapses the wavefunction, so upon measurement the system will occupy a state with a definite value of whatever you're measuring. So yes, it is essential that the two subsystems are in a superposition when they are in an entangled state. | We know that two particles were entangled because of the their measurement statistics. Specifically, an ensemble of similarly prepared two particle systems will violate a Bell type inequality if the two particles were entangled. |
When we're out of oil. Will there still be plastics? | Yep There are tons of different Bioplastics as they are called. some examples incluce... polylactic acid (PLA), Polyhydroxyalkanoates (PHAs). The wikipedia article does a good good of summerizing some of the common ones. If a chemical can be polymerized chances are we can turn it into a plastic for the right price. The reason why we arn't using them right now is because oil is still sooooo cheap compared to biological and renewable sources. Also I'm just going to go out on a limb and suggest that in addition to bioplastics we will go back to using nature's polymers, aka wood and stuff like that. _URL_0_ | 1) Crude oil is not one substance. It is a mixture of a ton of different products that need to be extracted through various processes: [_URL_0_](_URL_0_) & #x200B; 2) Plastics are extremely versatile and a ton of different processes can be used to get different products from what is technically the same plastic. For example, nylon can be used to make strong hard plastic products using one process, it is also used to make clothing and tons of other things with different properties: [_URL_1_](_URL_1_) & #x200B; Basically plastics are made by taking a base chain of hydrocarbons (things with hydrogen and carbon in their make up) and making them form links together. Where those links form change the properties of the end result. We have gotten pretty good at making those links form where we want them to to get what we want. |
Why was Siberia so scarcely populated? | As a Canadian, I'm going to point out the the regions of Canada that look like Siberia are EXTREMELY SPARSELY populated. They just cannot support large populations. Most peoples living in these areas survived in a hunter/gatherer capacity and now pay exorbitant amounts of money to have food shipped in my airplane. The parts of Canada that are populated are much more similar to the American mid-west, east coast, and north west coast (Washington = British Columbia), than Siberia | Much of that land is sparsely populated. Russia could take it because no one else wanted it enough to fight for it. |
In case of blood loss - is it possible to save yourself by drinking it back (until getting treated)? if not, why? | No. For one ingesting all the blood will probably make you vomit. And two by the time passes your stomach and digestive tract, its not blood anymore. The acid in your stomach would have broken it down. | You can, that has been disproven. You should probably still drink SOME water (because the other beverages my have some properties that reduce your body's ability to absorb the water) but the current condition is that ANY water you intake, is good water. |
Is our aversion to sounds like nails on a blackboard, squeeking on glass etc. Instinctual or is it learned/culturally based? | There was a short article in the May 2012 issue of National Geographic that mentioned that the parts of the screech that are within 2000-4000 hertz are "highly amplified once inside [the ear canal]." They attribute it to a "piercing reverb" that can even cause a "physical reaction." The go on to mention that "even imaging the sound can cause perspiration and increased heart rate." Based on that I would say the reaction to the sound is not learned or cultural but rather a byproduct of our physiology, but the learned response to a particular source of that sound certainly is. | Due to the way the human ear is built, certain frequencies of sound are amplified or made louder (the reasons for this can get a little technical, but if you're interested you can read about it [here](_URL_0_)). Sounds with a frequency of 2000-4000Hz (such as nails on a chalk board) resonate in a certain way in our ear canal, which causes them to be amplified enough to make us feel pain. **Like you're 5:** Nails scraping a chalkboard make an unpleasant sound to begin with, and this specific range of sound resonates with your ear in a way that makes it even louder. To put that last bit even more simply, the sound bounces off the curves of your ear in a certain way, which makes the already-awful sound even louder. EDIT: typo |
Why does wine age in the bottle, beer goes skunky in the bottle, and whiskey doesn't change in the bottle? | Beer goes skunky because there are certain flavor compounds from hops that break down when exposed to UV light, from sunlight or even in-store fluorescent lights. Even some beers age in the bottle. Sierra Nevada beers are often bottled early, and finish aging as they make their way from the brewery to distributor and eventually retailer. I assume some other brands do that as well. Whiskey's aging needs a barrel, because the flavor compounds come from the charred wood in the barrels. Once it's bottled, there are no flavor compounds in glass. | When a bottle says aged 12 year they mean 12 year in a barrel not the bottle. Liquor, for example whiskey, picks up flavor from the cask/keg it is barreled in. The cask/keg can impart very subtle textures and flavors to a whiskey. Wine, on the other hand, ages differently than liquor. As wine ages, a chemical called 'tannins' breaks down and the result is a "smoother" tasting wine. |
Can you make a laser-knife out of a laser going through a half-silvered mirror (or one-way mirror), and reflecting off a mirror? | You actually described [how a laser itself is constructed](_URL_4_). There are two curved mirrors inside the laser, one is partially transparent. The transparent one is the one the laser beam comes out of. In between the two mirrors is a device that essentially creates photons from electricity (gas, diode, etc) that shoot out in random directions. Photons that happen to go in the direction of the mirrors get amplified each time they go through the device. [Here's the wikipedia link if you want to know more.](_URL_3_) | The laser is made up of multiple beams of light. Each beam is not powerful enough to etch the glass but if they are all focused on the same spot, then their combined energy will make a mark. |
Why is Botswana so successful and stable compared to many of its neighboring nations? | Botswana is stable - partially because it's lush with precious gems and metals. The government owns 50% of diamond mines and competes with various major private international corporations. Because of their wealth, they are able to pay off foreign debts in a timely manner, which boosts their credit and attracts foreign investment. Investors need a stable, growing economy. So the *now wealthy* government actually enforces rules to assure future prosperity. Botswana is experiencing a "virtuous cycle". | I think this is probably more of a question for /r/AskSocialScience. Botswana's success is down to a number of reasons, most importantly good governance. It is one of the more stable African countries and has one of the longest continuous democracies on the continent. Botswana has also done well to combat corruption and is considered the least corrupt African country, [as proved by the recent Transparency International report.](_URL_0_) In terms of economy, Botswana is the largest producer of diamonds and has mining operations part owned by the government. The nation can benefit from this because of the lack of corruption unlike other resource-rich but severely corrupt African countries. However, Botswana needs to move away from diamonds as a mainstay of it's economy and is trying to build up its financials sector but we'll see how that works out in the coming years. |
Where does the name Ozymandias originate from? | Ozymandias was the Greek moniker of the Egyptian pharaoh, Ramesses II. It was a translation of his throne name, *Usermaatre Setepenre*, meaning "Ra's Chosen Truth, Chosen of Ra." | Carrying on from what I said in the other thread, "Oz" is actually believed to have come from a filing cabinet in Baum's study-- it had three drawers, one of which was labeled O-Z. My source (and one of my favorite sources for information about the genesis of Oz) is *The Annotated Wizard of Oz* by Michael Patrick Hearn. However, Baum was fond of pithy two-letter names (compare the neighboring land of Ev, or the characters of The Great Ak and The Great Bo in *The Life and Adventures of Santa Claus*), so he may have just made it up whole cloth using a pattern he often favored. |
How exactly is the caloric content for a food determined? | Using a calorimeter. It's like this: _URL_0_ Basically, the food is burned inside an insulated container and with the amount of energy that is given off, we can calculate calories. Remember, the Calorie is an actual measurement, however it is not used for food. The calorie that you think of in foods is actually kcal, which is 1000 calories, which is the chemical measurement. From these results we can try to get an even better estimate by looking at the contents of the food. Proteins, carbohydrates and fats being the main structures that food is made of. We know the exact amount of calories that are in 1 g of each macro nutrient (fats, carb, protein) and can estimate the calories in the food by adding up how many grams of each are in the food. | A food calorie is 1000 calories, 1Kcal, or a Calorie, spelled with a capital. In an aluminum calorimeter, a weighed sample of the food is burned in pure oxygen and the amount of heat produced is determined, per gram of food. While it is true that not everyone digests and absorbs equally, that is how the table of values is determined. The label amount is an average. |
What did people think about static electricity before electricity was discovered? | This is one of the most commonly posted questions here, I will just cut and paste what u/Mictlantecuhtli said last week: here's always room for discussion, but perhaps the section on Ancients' views of static electricity will answer your inquiry. _URL_0_ | If you're interested in the subject, I highly recommend the documentary Shock and Awe: _URL_0_ It covers exactly what you're asking about. How we went from treating static electricity as a novelty to actually using it as a tool. One thing I found really interesting was how Electricians were originally party magicians. They'd take various tools for creating static electricity and effects and show them off at parties. |
Did duels actually take place before a battle | Duels were a part of the war in those days,it was a sort of introduction to the war and both sides would send 3 champion fighters or whatever number is _URL_0_ the first war that the Muslims fought 3 fighters were chosen but the Quraish enemy asked the Prophet to send 3 other fighters who were his immediate family so his uncle Hamza and two cousins Ali and Ubayda went forward and won their duels but Ubayda was wounded and Ali killed his opponent for him and then took Ubayda back to the Muslim ranks where he died of his wounds shortly afterwards. Another thing to mention is that in Islam showing off or pride of any kind is prohibited the only time it is acceptable is in the battlefield against an enemy,so many of the elite champion fighters in the Muslim army used to distinguish themselves by wearing a red or colourful headscarf/turban to attract opposition fighters and champions in the midst of the battle. | I think that depends entirely upon the situation,but one could certainly examine the single combats during the Gothic War between the Eastern Roman Empire and the Ostrogoths of Italy. At the battle of Taginae (where Narses, the Roman general, truly broke the back of the Goths) King Totila sent forth the fearsome Coccas, who was to duel the Armenian soldier Anzalas; they fought mounted, and Coccas charged, with the conflict being over in mere minutes. Anzalas swerved away from Coccas' thrust and struck him down. Though the fanfare leading up to a duel in late Antiquity might have been grand and lengthy, the combat did not often last for a long time. I hoped this helped. Sources: Procopius' history of the Gothic War. |
What are the first things that scientists look for in a planet to see if it may support life | When examining other solar systems it is possible to determine the habitable zone around the main star. The habitable zone or ecosphere is the zone in which organisms (similar to the ones on Earth) could exist. It is also possible to determine the atmospheric composition of other planets simply by observing the change in light rays emitted from the parent star when they pass through the planets atmosphere. Typically scientists look for Hydrogen, Carbon and Nitrogen however we know very little about how life is actually created so there could be organisms that can survive in ways we can’t even imagine. | There are seven criteria biologist used to recognize life 1) Homeostasis 2) Organization 3) Metabolism 4) Growth 5) Adaptation 6) Response to stimuli 7) Reproduction see _URL_0_ |
why are YouTube comments *so much worse* than most other places on the internet? | Another few points: Another aspect of it is the voting. YouTube doesn't have much of a deterrent for trolls, spammers, etc. whereas in reddit, the threat of being shot down and downvoted into oblivion keeps a lot of people in line I'd say. Especially for regular users. But the same system also keeps a lot of people from posting their valid opinions, which is a bit of a drawback imo. Also, YouTube's comments are almost completely unregulated. Here we have mods who make the effort to delete the spam comments that do pop up. | Because people come to reddit to post specifically, whereas people go to youtube to watch a video. The comments section there is an afterthought at most. The equivalent to yelling at the TV. Also, the up/downvote system encourages posting things that people will agree with, or find useful. Also, subreddits tend to be more heavily moderated and has rules. Also, back to the up/downvote system, because of the way comments get sorted by default, even if there are "bad" posts, you are less likely to see them because they will be at the bottom of the thread (and perhaps hidden away under the "click here to view comment with negative threshold" button) |
Why are the Navier-Stokes equations called "the Navier-Stokes equations" instead of just "conservation equations"? | We don't refer to it as the conservation of momentum equation because it isn't the most general form of conservation of momentum. Ultimately the Navier-Stokes' Equations are a special case of [Cauchy's momentum equation](_URL_0_) which describes momentum transport for *any* continuum. This reduces to the Navier-Stokes equations when the arbitrary stress tensor sigma is replaced with the Newtonian constitutive relation. We don't normally talk about Cauchy's momentum equation in fluid mechanics because unless you dabble in non-Newtonian fluid mechanics the Newtonian constitutive relation is the only form for the stress tensor that you're going to use. As for why we don't call them Newton's Laws... well... Newton's laws already refer to: N1 - Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. N2 - F = ma N3 - For every action there is an equal and opposite reaction. | [The equations that describe them](_URL_0_) are known, but " theoretical understanding of the solutions to these equations is incomplete. In particular, solutions of the Navier–Stokes equations often include turbulence, which remains one of the greatest unsolved problems in physics, despite its immense importance in science and engineering. Even much more basic properties of the solutions to Navier–Stokes have never been proven. For the three-dimensional system of equations, and given some initial conditions, mathematicians have not yet proved that smooth solutions always exist, or that if they do exist they have bounded kinetic energy. This is called the Navier–Stokes existence and smoothness problem. Since understanding the Navier–Stokes equations is considered to be the first step to understanding the elusive phenomenon of turbulence, the Clay Mathematics Institute in May 2000 made this problem one of its seven Millennium Prize problems in mathematics." |
How is a microwave able to warm up food but not things like plastics, papers, glasses, etc.? | Microwave oven work through something called Dielectric Heating. It only works on stuff that is made of a Dielectric Material. When a dielectric material is in a magnetic field, the molecules turn to face the direction of the field. A microwave from the viewpoint of a stationary molecule is a rapidly changing magnetic field. So the molecules starts turning quickly back and forth to follow it. This rapidly turning is the heat the microwave causes. Things like water, fat and sugar are dielectric materials, so they heat up. Things like glass and some plastics are not dielectric materials so they don't heat up. Often a material is dielectric because the molecule has more positive charge at one side then on another side. Things like glass molecules are made out of molecules that don't have any built up charge in any particular place. | Microwaves work by emitting light of a certain frequency which excites water molecules in the food, causing heat. The light can't always penetrate too deep into the food while maintaining its energy, which means the outside of the food gets hot and the inside stays cold. |
Where does plastic come from? | Plastic is made, primarily, of crude oil products, along with other naturally-occouring products. Wondering how it comes to be even though no new matter can be created is a bit like wondering if the toast I ate for breakfast materialized out of thin air. _URL_1_ | A lot of the plastic is from fishing nets/equipment. It's used in the ocean so when it's discarded or lost it obviously ends up in the ocean. |
What makes a fluid either compressible or non-compressible? | Gases are compressible because the molecules have a lot of empty space in between. If you push on a molecule, it has a lot of empty space to move into. So it is easy to compress the gas. In a liquid, the molecules are almost touching. (Molecules don't really have well-enough-defined boundaries to "touch", but it's OK to think of them that way to a first approximation.) There is a little bit of space, but not much. So when you push on one water molecule, the neighboring molecules push back on it, and their neighbors push back on them, and so on, making liquid water much harder to compress than a gas. | All materials are compressible, including solids. The measurement of this property is [the bulk modulus.](_URL_0_) You can compress a block of steel if you press hard enough. How a material "takes less space" depends on the material in question (crystalline solid vs gas, etc), but you're always just pushing molecules closer together than they were before. There is some finite force resisting molecules being pushed closer together, and the more external pressure force you put on them, the closer they'll get. So you're asking the wrong question. All materials are compressible, but in many cases the compressibility is so small it can be neglected compared to other effects. The right question is "when is it reasonable to assume a material is incompressible?" which depends on what physics you're interested in investigating/predicting. |
How we found the void in The Great Pyramid of Giza? (how Muon Tomography really works) | ELI18+ is the Wikipedia article. There are particles with high energy hitting the atmosphere. In the collisions, muons are produced, tiny particles that don't live long. The muons travel downwards (typically not directly vertically, but still downwards) until they are stopped. Rock stops more muons than air. If you put a muon detector somewhere, the amount of muons you detect depends on how much rock is above you. If your detector can detect the direction of muons as well, you can detect the amount of rock in all directions above you. If you expect 100 meters of rock from the pyramid in some direction, you can calculate how many muons you expect and compare that to the measurement. Fewer muons? - > more muon-stopping rock in the way. More muons? - > Less muon-stopping rock in the way. Repeat that measurement in multiple places and you get a rough idea how much rock is where in the pyramid. | Much nicer. The pyramids at Giza were once covered by fine white stone. The remnants of such stone can still be found at the top of the pyramids. Over the millenia, these stones were stolen or destroyed. [This page goes into detail about the beautiful outer stones.](_URL_0_) |
Why do mentally challenged individuals and those with down syndrome have very similarly shaled heads/faces? | Down Syndrome has characteristic facial features including flattened noses and eyes with an epicanthic fold (slanted). Which is why they used to be derogatorily called "mongoloids". Though the resemblance based on these two facial features is purely coincidental. Those with Downs tend to have a large number of physical deformities that are not present in healthy individuals, such as umbilical hernias, low muscle town, narrow roof of the mouth, and a proportionally large tongue, among other things. The disease is caused by a genetic mutation which results in the individual having three copies of Chromosome 21, instead of the usual two. The exact mechanisms of the physical deformities caused by the overexpression of this chromosome are not well understood. The mental impairments may be caused by an excess of amyloid beta peptide in the brain, similar to Alzheimer's disease. _URL_0_ | They don't really look THAT much alike. It's just that the Syndrome alters the look of the person in a certain way which makes their face distinguished from faces without the disease, so you spot them, can tell from their face that they have down syndrome and place them in a group with other people who have the same condition. This is also the same reason why some people say that all black people or asians look alike (When they themself are white), you see that they are obviously different from you and place them in the same category. |
When ISIS demands 2 million dollars, why can't Japan pay fake money or wire 2 million and then pull it back once hostages are released? | "Hello, I'd like to dispute a charge on my credit card." "Okay, sir. What was the amount of the charge?" "Two million dollars." As others have said, electronic transactions are not acceptable for precisely this reason. Even cash might not be acceptable because it can to an extent be tracked, but the ease of use might make it the best way for ISIS to agree to accept it. They've done it before. Gold bullion would probably be the most untrackable, but also very difficult to obtain and deliver. Also, for the record, the amount ISIS demanded of Japan was two *hundred* million, which is so far outside of reality that it isn't a serious request. It's just an attempt to get themselves on the news without sacrificing one of their hostages. | Cash is exactly what ISIS would be wanting. Not only would they not want any kind of electronic trail leading to their accounts, but the sort of people they're then going to spend the money on (illegal arms dealers, mainly) are also not likely to have easily-traceable bank accounts. The money that doesn't get spent on weaponry and vehicles will then mostly be used as payments for those working for them, and bribes to police chiefs and government officials in the areas they control. Again, this is something that's much easier to achieve with cash, especially globally-recognised currencies such as US dollars or Japanese yen. |
How do medical examiners conclude a person's time of death? | 1. The Rigor Mortis : Starts roughly after 1-2 hours after death and is gone after ~2 days. Good way of making a ballpark guess, because usually the different muscles turn stiff in a typical order (even though this is not very reliable). Has the big upside that you can make a good guess after examining the body for a very short time. 2. Body temperature : The absolute standard. Pretty reliable if you know the exact outside temperature where the body was after dying. If the body was moved and you don't it's very unprecise. Good think is that you usally know the temperature though. 3. Lividity : Is the first proof of death that is visible under normal circumstances. Can help to increase the precision of the guess made by rigor. 4. Decay. Most notably larvae of insects that hatch after a specific time. Can be pretty reliable, not really used in daily practice though. Other signs of decay can get important if the death happend a longer time ago, even though things get very unprecise pretty soon | It depends on where the death takes place but it's usually up to the locality. _URL_0_ |
How can we classify certain animals as herbivores, if they probably "accidentally" eat small animals, e.g. insects, while consuming large amounts of plants? | The term "Herbivore" means PRIMARY diet is plants. It doesn't mean EXCLUSIVE diet is plants. We're not talking rabid vegans here. They probably get a fair amount of soil in the food they eat, particularly ones like sheep that crop close to the ground. But we don't call them dirtivores because of that. | You need special teeth, bodyplan, and digestive adaptations for what you eat. If an animal finds itself in a situation where it is only eating one food (for example, polar bears not having access to plants, or grazing animals having such abundant grass that they don't eat anything else), natural selection will push it towards the adaptations that make it better at eating that. *T. rex* had omnivorous ancestors, but once you're a *T. rex* you don't really need those adaptations for eating plants. And part of it is the different body plans required for plants and meat somewhat cancelling each other out. Large herbivores tend to be potbellied, because plants are difficult to digest and require large digestive tracts. Predators tend to need to be swift and sleek. So a predator or an herbivore can specialize more than an omnivore. As for why you would be one or the other, herbivores have a steady supply of food that can't run away or fight back, while carnivores get easier-to-digest, high-protein meals. |
What are vitamin supplements made out of? | In the example you cited, bacteria. There is a non-animal source for every vitamin we need. | The basic gist of it is that scientists in the early 1900s identified vitamins, usually by what deficiencies they prevented, and started naming them A,B,C,etc. but as it turns out, the what they originally thought was one vitamin B turned out to be many different compounds so it was split up into B1,2,3,etc. And other vitamins turned out to not actually be vitamins, leaving gaps. |
Why does lighting a match in a bathroom help when someone's caused a stench in there? | When a match is struck, the first thing to burn is the head. The head of a match contains a chemical cocktail that includes a lot of sulfur. In the initial burst of combustion products there is therefore a lot of sulfur dioxide. Sulfur dioxide is an extremely pungent substance, to which the smell receptors are extremely sensitive. But it also has a very efficient numbing effect on the sense of smell. You can smell a minute amount of sulfur dioxide, but when you have done so, you will not smell anything else for a while. Sulfur dioxide is a gaseous combustion product, so if this is the main factor no-one wins the bet. It is not flame (plasma) nor smoke (solid aerosol). You can easily test this one, because if it is the main factor, other flames, like a spirit stove, a cigarette lighter, or a candle will not mask smells nearly as effectively. Again, first result on Google... :/ | It just masks the smell with something even stronger. |
When people talk about NSA Spying, who is actually looking through your personal data and why are they tracking you? How does anyone have time to search through every persons private life? | Almost certainly no human ever looks at your data unless you are involved in something shady. There are undoubtedly certain triggers and behaviors which might generate some closer scrutiny, but a normal person doing normal things is of no interest. | Watergate was a crime. While the NSA is completely legal. And by completely, I mean completely. What they do to foreigners (spying on them) is their entire job. It's what they're paid by Congress to do. Every nation has a signal intelligence program like this. Furthermore, what they do to Americans is the equivalent of reading the outsides of their mail envelopes. (And using subpoenas to get this information from phone companies.) Plenty of lawyers do exactly the same thing. In fact, in the old movie "Clueless", the lawyer father is in a lawsuit going through subpoenaed phone records. If the Supreme Court decides that mass subpoenas of public information is an intrusive search, then it will stop being legal. But it isn't even close to being Watergate. |
How long after death does all brain activity stop? | Define death a little better, because many would call the complete cessation of brain activity death. | Death is a complicated beast and there's rarely a single black-white line. As stated elsewhere in this thread, circulatory arrest precedes whole brain death by several minutes. But I have personally viewed the electroencephalographic records of people whose hearts suddenly stopped. Their brain waves immediately go flat. That would imply no meaningful brain function. |
Why do we humans still have anxieties that formed thousands of years ago, but have no use today | Because those anxieties don't prevent us from getting laid and passing on our genes. They don't "evolve out." If an instinct behavior *helps* you survive and pass on your genes, it sticks around. If an instinctual behavior *hurts* your chances of makin' babies, it doesn't stay around through the generations. But if it neither helps nor hurts, it may stick around anyway because you pass along those genes to approximately 50% of your young, or 100% if your partner also has the gene. So say for example humans that run screaming from spiders are the only humans that survive for ten thousand years, because monster spiders are out to get everyone. Then the environment changes, and the monster spiders die off. But the only humans left are the ones instinctually scared of spiders. So their children, today's man, are still gonna stress about spiders, because being scared of spiders doesn't stop me from getting laid. | The same reason why people with anxiety are anxious even though they know there is nothing to be anxious about. We're not always in control. |
Why can they play movies on TV with explicit language and violence on any channel but they can't play songs with explicit language on the radio? | There are very specific FCC rules about language and adult content on *broadcast* television. The FCC regulates such content on radio and television broadcasts. However, the FCC doesn't have that same regulatory authority over cable/satellite transmissions. So, if it's a channel that isn't broadcast, but only available through a satellite or cable provider, then it's really up to the channel itself what kind of language and content they have. The distinction is the same on radio -- satellite radio can have content that terrestrial radio would never be permitted to air. | Cable TV (like comedy central, and the like) aren't federally regulated. The only censorship they take part in is self-censorship. They don't show nudity and limit curse words because their advertisers ask them to. Radio is federally regulated, because it comes into your house whether you want it to or not, so the government has the right to regulate it. |
Why do certain strong scents give you a headache? | Could be your individual level of sensory hypersensitivity. Essentially, too much sensation causes the headache. We intuitively 'get' that loud noises or bright lights can give you a headache. But strong smells can do that too, in the same way. | Nothing, usually. Headaches are typically caused by inflammation in the sinuses due to allergies, infections, or blood pressure issues. |
How do movie uploaders actually benefit from uploading piracy content? | Copyright infringement, generally speaking, is not a criminal offense. It is a civil tort. That means they're risking being sued, not going to jail. Some people actually do make money off of pirated movies. A lot of black/grey market groups are willing to pay big bucks to get pirated films so they can copy them and sell pirate DVDs. The guys who upload online are usually just doing it for rep in the community. It's a big deal for a release group to be the first guys to get out a new hot title (or the first to do it at good quality). Gets them tons of rep and goodwill in the scene. | The film industry would make the case that revenues would be significantly higher if there were no piracy. Their position is that every pirated copy is a loss of the profit from that copy. Clearly there are multiple viewpoints on that. One is the realization that not every person pirating a copy can be converted to a customer if piracy were technically impossible. Another is a number of studies indicate that a lot of people pirate a copy of a film or song to decide if they want to actually own it. Quite a few of these people subsequently purchase legitimate copies of the IP. |
Where do phosphodiester bonds occur? | Lots of questions here: 1. Phosphodiester bonds happen in a lot of places, including to amino acids that have a hydroxyl group (e.g. serine). They are also how you get the 'phospho' in 'phospholipids' that make up biological membranes. 2. They are inter-nucleotide bonds, they connect the 5' and 3' carbons of two nucleotides that are 'next to' each other in the nucleic acid chain. 3. Polynucleotide doesn't get used often as a term, but generally the difference between 'oligo' and 'poly' when it comes to polymers is poorly defined and is just a term for length. Nucleic acids that are \~3-40 nucleotides generally get called oligonucleotides, in my experience. If people were using the term polynucleotide more often, I'd hear that an assume something > 50 nt in length. | Think of a phosphate as a tiny spring and ADP as a spring holder, but one where the niche is too small for the spring to slide in. One would have to compress the spring to make it fit, and the spring+holder set is ATP. Now, as you may imagine, the compressed spring can do some kind of work if released or put into some little machine, in the same way a clothespin can snap shut. Similarly, ATP generally transfers one high energy phosphate (the compressed spring) to a little machine like the Na-K pump. The energy from the phopshate then powers the pump. That's some nice physical chemistry! |
Why should I get the factory recommended oil in my car? | The oil the manufacturer tells you is the guideline. Putting in thinner oil will not provide proper oil pressure and lead to metal on metal contact. That said, jiffy lube is the absolute LAST place you want to take your car to,whether it be Audi BMW Honda Chevy ford GM. The guys that are changing your oil have about 10minutes of training. You're seriously better off finding some neighborhood high schooler that loves to work on his Honda to change your oil | It's a requirement for (most) products imported into the USA. [Source 1](_URL_0_.) [Source 2](_URL_1_) |
What exactly is the big deal about left shark? | Here's a quote from some site called mental floss: "The dancer who came to be known as “Left Shark” has become an instant meme, not only because of the frankly weird but cute shark costume, but his seemingly confused and clumsy fin movements in those few seconds. These poor guys danced in multiple costumes that night, with little rehearsal because the original dancers from Mesa Community College were replaced by Katy Perry a few days before the show. Also, their choreographer said they were supposed to be goofy. Not that any critique of Left Shark’s performance mattered; the internet immediately fell in love with him." In short the internet loves him because he looks funny, and overlooks right shark the same way no one remembers the second guy on the moon, Leonardo DiCaprio I think it was | There hasn't been drastic changes to their environment, whereas humans have seen major changes, and changes to their features have allowed them to fight ahead of the competition. If you think about it, there isn't much that would make a shark drastically better at catching fish. |
Why do people scream? | Why anything evolves we can't say beyond,, at best, educated guesses, but screaming has a fairly uncontested advantage evolutionarily: it informs everyone around you that there's something to be alarmed of. If I'm out hunting with my people and I hear a scream some 50 metres over there I can quickly figure out that 1) that's where the guy is and 2) he needs assistance, and I should be careful going there because whatever hurt him could probably hurt me. Everyone screaming in a situation of obvious danger is unlikely to be useful, but it's also unlikely to make most situation all that much worse. If the building is collapsing whethet people scream or no you're getting the same outcome; there's little you can do if the building is already going down. As for any case where screaming escalates the danger: well evolution isn't perfect. It can't account for everything. | If you think they scream loudly when they're playing, just try pulling one into your car. |
We usually add "oholic" to a word to insinuate that someone is addicted to something. For example, "alcoholic", "chocoholic", shopaholic". Why don't we ever refer to drug addicts as "drugoholics"? | Most of those are just kinda slang terms for things that aren't addictions and are puns based in "alcoholic". By all rights, it should be more like "choc-ic" because the "hol" part is from alcohol. (Hence why one Simpsons episode has Homer say he's a rageoholic; he just can't live without "rageohol". They're not supposed to be serious terms at all. | They're both ultimately chemical addictions, when viewed on a molecular level. For the addict, the first just simulates, or, in some ways, improves upon the second. For example, cocaine is similar in effect to experiencing the rush of romantic love, but more reliable. Want a "Eureka!" high without inventing anything? Opium. [Pity about the ways in which they don't improve on the experience...](_URL_0_) Think of a chemical addiction as basically a crude attempt to hack the brain... |
Are there any animals that start out bigger and get smaller as they age? | There are a few species of frog, such as the [Eastern Dwarf Tree Frog](_URL_0_), whose tadpoles are larger than adults. | Because "smaller animals die faster" is an incorrect premise. Some turtles live to be 200 and elephants don't. So that disproves that generalization. Animals live as long as their chromosomes stay intact. The faster they degrade the faster you age. So it comes down to genetics and not necessarily how big you are. |
When will humans become hairless and why did we lose our need for hair? | It is doubtful we will lose it any time soon, we currently like how it looks and select for those that have nice hair. One theory for why we lost our body hair is that losing it greatly helped us keep cool and also may have reduced parasites that reside in fur. _URL_0_ | Remember that humans are only designed to live about 20-30 years max. Hit puberty, breed a bunch and maybe help your offspring hit puberty. After that evolution doesn't really care what happens to you. If humans had evolved to prosper by attracting mates and breeding with them over and over for a hundred years we probably wouldn't start balding until 100. |
Why are kids taught to use "x" to mean multiplication until the age of ~11, when they switch to "·"? | It is very important that they learn what a punctuation mark or decimal point is. It may be difficult for young kids to discern the difference between . and · especially when handwritten. x as a multiplication symbol only works until you need to learn algebra. Then x becomes a variable. It is then necessary to use a different distinct multiplication symbol. | "X" is similar to the symbol for "thing" or "object" in Arabic, the language in which the rules of Algebra were first expressed. When translated the symbol became X because it was good enough for the purpose. |
Why is AIDS usually connected with homosexuality? | it is much easier for men to give people HIV through the bodily injection of semen than it is for women to give HIV. HIV can easily go from man to man or man to woman, but not so easily from woman to man or woman to woman. M to M to M to M to M, and you see why it has such a devastating effect on the gay male community. | Gay people can and do reproduce quite frequently. There are many homosexuals forced into heterosexual relationships due to religon, family, or societal pressure. They can also be sperm donors for heterosexual couples through fertility clinics. |
Why the moon is sometimes visible during daylight. | Because the moon reflects enough sunlight to be visible during the day. | The moon can be seen because the light of the sun bounces off of it and travels to us. The amount of light bouncing off is sufficiently bright enough to be seen through the sky in the daytime. Why is the moon visible when the sun is up? It's all about relative angle. The moon is far enough away from us that even when the sun is in our sky some of its light is still striking parts of the moon that face us. In terms of looking at the sky, the farther the moon is from the sun the 'fuller' it can be. |
Why does waiting to save a file make it download faster? | The browser has already started downloading the file when it displays the "save as" dialog. It's continuing to download it in the background to your temporary folder while it's waiting for you to respond. You're not actually gaining any speed. It's smoke and mirrors but it's a useful tactic nonetheless. | When downloading files, there is an algorithm being used for checksum error correcting. This algorithm is making final checks to be certain all the parts of the download are correct and in order. That takes a few extra seconds to complete. |
How does WiFi speed get increased | Your WiFi speed isn't changing, it's the speed of your internet connection. DOCSIS 3.0 - the standard that cable modems use - is capable of handling over 1000 mbps if the provider is willing to send that much data & has the bandwidth to support it. These sorts of upgrades can be done by flipping a switch and/or upgrading the infrastructure around town without doing anything more than telling your modem to reset a connection. | I don't know what measure of signal strength you're looking at or what WiFi hardware you're using so there could be 100 different answers. Three possibilities stand out in my mind: a) When idle, your connection's sync rate will sit on a "best guess". When you're actually downloading, it can use the data sent and the error rate on that data to measure the *real* signal strength and it turns out that it's much lower than the guess so it needs to lower the sync rate. b) The router antenna increases its power when sending data. Maybe this causes the power supply to create more interference. c) You're getting a lot of multi path interference and your own WiFi signal bouncing off walls in the room is interfering with itself. |
Is time a vector quantity? | Given two events, the time separation between them is one component of their separation vector. | Treating time as a fourth dimension is a useful representation, especially in relativity where space and time are interrelated. It's a widely used representation in physics, since it makes many theories conceptually simpler. Whether it's "true" in any sense is really a philosophical matter. As to whether time being a dimension would imply that determinism is true, the answer is no. Determinism is an entirely different issue that arises from the physical equations that describe the universe, i.e., whether the future can be exactly predicted from the present. |
Is horizontal gene transfer from genetically modified food to gut bacteria a legitimate concern? | The abstract says they didn't observe horizontal gene transfer. They observed DNA remaining in the gut. I've seen claims it can be found in blood as well. The thing to remember is that GM DNA is exactly the same as all other DNA. The tracts used to transfer it into the genome are long gone, and it is more immobile than many host genes. There's no reason to fear this DNA floating around anymore than the genomes of cow, pig, chicken, and potato genomes floating around inside you. | We have no idea. The study of gut bacteria is incredibly new. We know that transplanting a healthy gut biome improves things, but only in people who effectively have none. The "ideal" balance and its effects on digestion seem to differ by person. And there's virtually no FDA confirmed benefit to orally ingesting probiotics outside of, again, certain extreme cases. (We're not even entirely sure which bacteria taken this way survives the digestive process.) But given it's confirmed as important for general health, but not exactly how or why, and there's really no health risks associated with it that we can see, we're at peak opportunity for an explosion of snake oil and insane claims made about it. |
How did Ashley Wagner make the American Figure Skating team after losing in the trials? Is there precedence for something like this? | Olympic selection is at least partially subjective, so even though she only came in 4th in the trials, she had a strong enough international competition history otherwise that whoever makes the selection decided that she would be an asset to the team. | hi! not discouraging further contriubtions, but FYI, there was a similar question just last month. Catch up on the discussion here ~ [Where the Soviet hockey players who lost "The Miracle on Ice" game punished for their loss to the USA?](_URL_0_) |
what is the meaning the test is more specific but less sensitive ? | Sensitivity is the true positive rate for a test and specificity is the true negative rate If you have a highly sensitive test and it says you don't have something, then you don't have it, because it's high sensitivity means it would tell you you had it if you did(and also potentially if you didn't) If you have a highly specific test that says you have something then you have it, because it's high specificity means it would be negative if you didn't have it(but also potentially if you did) Sensitivity and specificity tell you about the true positive and true negative rates, from those two you can figure out the false negative and false positive rates and decide what your test will be good for and how many wrong answers you expect to get | assuming no knowledge of the test, it does not matter. |
Why do flies and other flying insects not have the reaction to fly away when a huge hand is swatting them away constantly? | Insects do not have a brain. All their actions are based on a complex set of reflexes to various of events. Being swatted away is unlikely to be something they are even capable of remembering. | If you place your hands behind a fruit fly and clap, the motion of your hands will cause the fly to take off (which they always do backwards), right into your hands, which are coming together right at that moment. The fly will be killed on impact between your two hands. If you simply swat at a fly, there is tons of fluffy air on the other side of it, which your hand will simply push it into. It *is* similar to the small mass ant thing because your astronomically superior mass will hold *you* somewhat in place if something that big hit you. Yes, you would go flying back also, but not before your body absorbs most of that shock. |
How can you be convicted of perjury if you answer that you don't recall a fact? | Perjury depends on a lot of things. First, did you knowingly make a false statement when you said “I don’t remember?” Second, were you under oath or otherwise subject to penalty under the law when you made the statement? And finally, did you make that statement about something that was material to the outcome of the legal proceeding? If the answer to all of these questions is yes, then you are probably guilty of the crime of perjury. But so what? The question isn’t whether you committed perjury by saying, “I don’t remember,” but rather whether or not you can be convicted of perjury for making those statements. Therefore they can find prove from your emails or text messages showing that you actually remember what happened, then you will be convicted for perjury. | Perjury is making a *deliberately* false statement. If you just made a mistake (or can convince others you just made a mistake), it doesn't apply. |
How are skin tags formed? | Yarr! Yer not alone in askin', and kind strangers have explained: 1. [ELI5 how skin tags are formed & why are they usually found in armpits? ](_URL_4_) ^(_3 comments_) 1. [ELI5 What are skin tags and why do we get them? ](_URL_5_) ^(_33 comments_) 1. [ELI5: What are skin tags, how/why does the body create them, and what's the best way to remove them? ](_URL_0_) ^(_3 comments_) 1. [ELI5: Why do we get things like skin tags and new moles as we get older? ](_URL_1_) ^(_1 comment_) 1. [ELI5: Why do we get skin tags when we're older? ](_URL_2_) ^(_70 comments_) 1. [ELI5: What causes skin tags, moles, and warts? ](_URL_3_) ^(_1 comment_) | A skin tag is actually a benign tumor that usually forms where skin creases, like the neck or armpit, and sometimes the eyelids. They are almost always harmless. They're very common (moreso in women than men), and thought to be formed by skin rubbing on skin, but the exact cause is unknown. They're safe to leave and safe to have removed - they don't grow back. Be sure to consult a dermatologist for advice. |
Why is it that whenever I download an iOS update, my iPhone's performance declines? | It takes a lot more effort, and therefore time and money, to create an update which has more features and at the same time runs as efficiently (quickly) as the previous system. And it's not in their financial interest to do so. They don't make money on the updates, they only make money if you buy a new system. So they just keep making systems that run more slowly on older phones, so that you'll get frustrated or jealous and buy a new phone. | In order to speed up operation, your phone saves relevant information for each app in caches and temporary files. If you're low on memory, your phone will go through all your apps and start cleaning out those caches and temporary files to reclaim some room. |
How Git is utilized, What is it? | Git is version control. It allows developers to avoid creating new folders for every new version or every time they make a change to the project ("MyProject v0.1", "MyProject v0.2", "MyProject v0.3", "MyProject v0.3.5- now with spaces instead of tabs", etc). Git saves it for you every time you make a "commit". Also git allows you to have multiple branches - essentially copies of the project dedicated to developing something specific. Once that something is complete, you can merge that branch back into the master branch. 3rd party services, such as Github, allow you to upload your git repository to the web. It works kind of like dropbox or google drive, but for code. It makes it easy for many users to collaborate on projects remotely. | GIT is source control. github is a social space for your code. There is plenty of good explanations of what git is, but the ELI5 is: github is a website that manages your git repositories. Say you were working on some codes, and your friend was working on the same code, and you both edited a file... How do you combine both your changes without losing anything? git! |
Why do designers hate Arial but love Helvetica? | Helvetia is a timeless font with several variations ranging from condensed to extended. Arial comes in narrow, regular, bold, and rounded. There are also a lot of nuances in the kerning and leading that make Helvetia better (factually). Some of it is design snobbery but honestly Helvetia is much more powerful given its versatility through variations. That's said, if you love Arial, rock it out! I'm more of a jasmine guy ;) | There's a great documentary film on Helvetica _URL_0_. It's basically, as blahblahblah says, that it was designed to be very easy to read. |
what TB lab results mean | The Quantiferon test is a brand name for a form of interferon gamma release assay. Simply put if your immune system recognizes tuberculosis then it will release a substance when exposed to the antigen for that substance, a chemical marker specific to that infection. The first two zero results are for exposure to different kinds of TB and show your body doesn't react to them. The third is a test to see if your body is reacting to anything (which it is) as if it isn't then the test is inconclusive and you have immune problems. The "nil" is a measure of if there are any other antigens already in the blood from an ongoing illness that could cause those immune cells to release substances like the test measures, skewing the results. It is quite low so the results should be accurate. | For TB, if I'm not mistaken, it's about the [ventilation-perfusion](_URL_1_) (V / Q) matching of different areas of the lung. Perfusion is blood flow, so it's basically the ratio between air and blood supply to the alveoli per minute. In the lung's apex, V / Q ratio is high (essentially due to gravity, but it's more complicated that that), and in the base it's low. This means that the apex of the lung is a [good place](_URL_0_) for mycobacterium tuberculosis to proliferate, being the aerobe it is. |
Was scalping usually fatal? | Usually, yes. The trauma and blood loss alone would result in the deaths of many victims, and even those who survived initially would face a myriad of complications and would almost certainly [die if the skull remained uncovered](_URL_0_). Septicemia, meningitis, and necrosis were all worries when dealing with a scalping victim. Even against these odds, there are at least a couple of people who have survived, including [Robert Mcgee] (_URL_1_) who managed to survive after being scalped as a child. | I'm pretty sure tests have been done that prove that cutting a head off of the body doesn't kill it, it is the lack of oxygen and other chemicals that kill it. So yes, _URL_0_ is right in that it is "too gruesome" _URL_1_ |
Has there ever been a time in history when white people have been persecuted because of their colour? | In Zimbabwe, after the end of apartheid, there have been a lot of incidents of white people being targeted because of their [race.](_URL_0_) While kind of understandable because of the earlier apartheid situation it is whites being persecuted because of race. | Well it depends on how you define "racism". One way is based purely on the colour of the skin, and split the world into only about half a dozen different races (White/Caucasian, Black/African, etc. etc.). This was historically used in parts of the USA. However lots of (legal) definitions of "racism" now include "ethnicity" ([source](_URL_6_)), and lots of people would include ethnic discrimination when talking about racism now. So was there any race/ethnic discrimination in the past? Of course! (e.g. Romans & barbarians). |
What is the difference between a credit union and a bank? | credit unions are local and are owned by the members of the credit union. they usually invest money back in to community development. because the money is kept locally and is used to help the community, they're generally able to offer lower interest rates on all of their loan products. banks are large, sometimes multi-national corporations designed to generate profit for stockholders, not its customers. pros and cons are really basic--keep your money local, or support a large corporation. also, as stated before, interest rates are generally lower for the credit unions, so if you're getting a loan or anything, it's best to go through your local credit union. | Up until recently national banks had far greater perks to being a member than credit unions could ever hope for. You mention banks all over the country, but it goes beyond that. Bank of America has agreements with national banks in other countries. If you were in Germany in 1995, as Bank of America member you could pull cash out of ATM's inside Germany and be on your way. Credit Union members would have to bring cash, travelers checks, or attempt to get their credit union to try to wire money to Germany for a heafty fee. In other words they were basically cut off from their bank account anytime they left the country while Bank of America customers weren't. In modern times credit unions have mostly alleviated this problem with their collaboration in establishing the co-op network. Last decade banks again pulled ahead with the emergence of online bank features, and later cell phone applications. However credit unions have started to close the gap here as well. |
how big is a cubic mile? Can you give me a sense of scale of how many whatever's would fit inside one? | Maybe this will help. I used some very quick-and-dirty numbers I found online for the length, width, and height of an average car. Granted, these numbers vary a bit depending on the make and model, but on average, my numbers show that the average car is about 14 feet long, 6.5 feet wide, and 5 feet tall. So I took the number of feed in a mile (5280) and divided it by these numbers, and here is what I got: In one mile, you could park 377 cars bumper to bumper. In one mile, you could park 812 cars side by side. In one mile, you could stack 1056 cars, one on top of the other. So, if you multiply those numbers together (length x width x height), you get: 323,266,944. You could fit three-hundred-twenty-three-million, two-hundred-sixty-six-thousand, nine-hundred-forty-four cars into the space of one cubic mile. | Definitions. 1 cubic meter is 1000 liters. 1 cubic centimeter would be 1/100th * 1/100th * 1/100th of 1000 liters = 0.001 liters |
Is Hawking still correct? | Yes, Hawking is still correct. There is still no evidence either for or against the Copernican Principle. There *are* models of cosmology that have a preferred center and which make the same predictions as a cosmology based on the Copernican Principle. We appeal to parsimony or some other sort of philosophy when we say that the Copernican Principle must be true. For more details, you can read this response of mine: [How Valid is the Theory of Geocentrism?](_URL_0_). | What do you mean by 'why'? Are you thinking about Hawkings original motivation for looking into it or the mechanism behind it? I'm not sure what you mean. |
Why is Issac Newton so much more famous than Gottfried Leibniz | Both contributed a lot to Science & Mathematics but perhaps Newton's work on motion makes him more famous. Plus, Newton was English and so anglophone cultures would prefer to talk about him. | In terms of Calculus he wasn't. Both Newton and another mathematician named Gottfried Leibniz are now, after controversy over whether or not Leibniz plagiarized Newton's work, credited with independently inventing calculus at the same time. Newton figured it out c. 1665 while Leibniz arrived at it in 1673 so there is about an 8 year gap between the discoveries. However Leibniz published his discovery before Newton did. Source: [The Newton-Leibniz controversy over the invention of the calculus](_URL_5_) |
How do audio editors manage to dub movies without losing the rest of the sounds(i.e. ambient noises, background music, gunshot noises) | There are multiple soundtracks going on at the same time and each soundtrack can be adjusted individually. So they record the background noises, they record the voices and they record other things as well. When they replace the voices, they just switch out the voice track but keep others the same or adjust them. | The actors have mics following them everywhere on the set. The mics pick up the dialogue and from the tape made, the sound man can edit out background noises and modify the actor's voice. The recordings are made in multiple tracks and fixing the voices is not much different than how artists record songs. When you see shows where say someone is flying in a chopper and you can hear the pilot speaking normally, the sounds of the chopper are edited out using noise cancelling software. |
How does a fan cool down a room? | A fan doesn't cool the room (unless it's colder outside, there's an open window or door and the fan helps the airflow through it). However, we experience heat not necessarily by the absolute temperature of the air around us, but rather by the rate at which heat is exchanged between the air and our skin. When there's air flow around us, our bodies can get rid of heat more easily, which causes the sensation of cooling. | Short answer: it does. A fan not only adds extra motion to the air causing it to increase in temperature, but it also takes external energy and converts it to waste heat while moving the fan blades. As a result, running a fan in a sealed room will increase air temperature. The OTHER things the fan does, however, are: a) it moves cooler air past your skin, enabling your body to transmit waste energy to air molecules which are then pushed out of the way and replaced with less energetic air molecules that can take up more of your waste heat. Because of this, the moving air feels cool to your skin, even though on a whole, it is warmer. b) fans force airflow through an open system, such that you can pull cooler air from other places in your house to the rooms that are warmer by shoving all the hot air in the opposite direction. |
Why does sweat stain clothes yellow? | From what I understand, it's not the sweat, but a reaction caused by the sweat interacting with the deodorant. And apparently it can be cleaned with a baking powder mixture. | Possibly friction. Alternatively, allergic reaction to the fabric softeners and washing powder that was left from the machine. A long walk makes you sweat slightly, this dissolves these chemicals, your skin absorbs them slightly. |
How do electrons or positrons come into existence during beta decay? | > How is it possible for an electron or a positron to just come into existence during beta decay? Particles can be created and destroyed; this is an example. > What happens to the quarks that were previously inside the nucleons? One of the quarks changes flavor. | Beta decay does not release an electron or positron. Rather, in beta decay, an electron or positron is created. Let's look at a free neutron. When it decays into a proton, an electron, and an anti-neutrino, what happens is the neutron ceases to exist, and the energy of the neutron forms a proton, electron, and anti-neutrino instead. Edit: typos fixed. |
Pi is irrational, therefore it goes on forever. Could that mean that, within pi, you could find other irrational numbers, like √2, and vice versa? | We don't know. Obviously if you remove some of the first numbers of pi you get a new irrational number from pi. But we know that pi can't contain something like √2. But it could in theory contain something like e. /r/askscience has several more detailed posts about this(I guess they go a bit beyond eli5) _URL_1_ _URL_0_ | Pi is both trancendental and irrational, which means it goes on forever without repeating. It's not just a possibility, it does contain every possible number and combination of numbers. |
why are prices always a cent cut short? Like "5.99" "299.99"? | Two reasons. 1) people don't really pay attention to the cents so if the dollar is lower the price looks significantly lower. 2) cents are used as code in store so x.99=full price, x.98=on sale, x.95 = clearance. | It's a mental thing. On a subconscious level, 3.99 9/10 feels cheaper than 4.00, even though it's essentially the same thing. |
Has a panic attack ever been captured on an fMRI? | Yes, numerous times. This particular study was actually one of the first to observe a spontaneous panic attack (ones before had almost "worked up" patients to intentionally induce panic). It showed exactly what you would expect; amygdalic activation, particularly on the right. _URL_0_ | During a panic attack some regions of the brain become hyperactive. These can be identified using a functional MRI (a special type of MRI that shows what parts of the brain are active in real time). Multiple regions have been found to be affected, these include: The amygdala which is involved in our perception of fear & parts of the midbrain that are involved in how we experience pain. If these parts of the brain malfunction (for example by giving a larger or more sustained response to a perceived threat) then you can experience a panic attack. These areas and possibly even some we have yet to identify cause the downstream effects that people call associate with a panic attack. |
How does dampness make hot weather seem even hotter, yet also make cold weather seem even colder? | Damp air makes hot hair feel hotter because it inhibits the ability of the sweat on your skin to evaporate. Air can only hold so much water vapor and if there's already a lot of it in the air, less of it can be evaporated from your skin (which cools the skin). Damp air makes cold air feel colder because the increased amount of water vapor increases the amount of heat conducted away from your body. | Wind can make it feel cooler than it really is. Humidity can make it feel warmer than it really is. |
Why do some websites only show you the price of an item AFTER you put it in your cart? | They do that to avoid running afoul of manufacturer set minimum prices. Manufacturers of premium goods, generally sell them in expensive retail outlets (with skilled sales staff). If customers go to the store and take lots of staff time to make a decision but buy on a cheaper Amazon the retailers will go broke, and manufacturer will lose the valuable high touch sales staff. Legally manufacturers in the US aren't allowed to set minimum prices, but they can contractually require retailers not to advertise prices below a minimum amount. Only showing prices in a shopping cart doesn't advertise prices and is a way for stores like Amazon to not violate these agreements. | Two primary reasons. 1)Marketing, its shows the item less than it will actually cost. People like low prices 2) Taxes are different in each state. So for example an Xbox cost $199 in California and New York. But the final price is different because the tax is different. It could be $215 in one state and $220 in the other. Its easier just to advertise $199 + tax |
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