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Why do industrial size graphene batteries not exist?
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The pros of using graphene are negligible in comparison to the added cost of using it. Commonly used carbon materials in batteries are not much worse for their funcion, while they are much, much cheaper than graphene. TL:DR it's not worth it, graperhene is not the magical solution for batteries.
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Does the atmosphere above the Atacama or Sahara deserts have less oxygen than other places due to the lack of vegetation?
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Yes, but the changes are negligible when compared to the effects of altitude and temperature, because of their effects on atmospheric pressure. Air that is less dense will contain less oxygen. As you mentioned, the oxygen that is produced by plants, is circulated around the globe. The amount of oxygen at any given location will be more closely tied to the density of the air.
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Why antibiotics doesn't work on viruses?
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Antibiotics damage the metabolism or some structural components of the bacteria. The trick to antibiotics is that they are specific enough to be harmful to bacteria but not to the cells of the host. Viruses on the other hand don't have a metabolism of their own and their structure is extremely simple. They take over and use the metabolism of host cells to reproduce. Therefore they have very little, if anything, to poison, and substances harmful to either reproduction or structure of viruses is likely to be harmful to the host as well. DISCLAIMER: My background is in nanoscience and technology and not in virology or medicine.
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When batteries are dying in a remote, why can you hit it a few times and it works for a while.
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If you physically jar the batteries you can move ions around inside the cell and allow a few more reactions to take place. In some batteries the movement of ions slows so much that it prevents enough electrons from moving to lower the voltage below that critical threshold voltage requires to pass through the semiconductors. In some batteries gas bubble form on the electrodes; they aren't designed to, it just happens for different reasons. Jarring the batteries can move the paste around enough allow a tiny bit more surface area to react. In some electronics there is a miniscule current draw from the battery at all times. It's possible that if you shake the electronics you may disconnect the battery for a split second and allow the charge to build up on the battery enough to exceed the minimum threshold voltage for the device. This last bit was speculation and I accept being chastised for it
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How are accents formed?
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> What exactly happens to the vocal chords or throat when speaking in a British or French accent? Nothing happens to the vocal chords. By default, anyone's vocal chords are capable of producing any sound found in any language. When you're a baby, you're exposed to your native language or accent, and that's simply how you learn to speak. For instance, based on your comment I'm going to assume that you speak with some type of American accent. If you had grown up in Britain, you'd have learned to pronounce words slightly differently, and if you'd grown up in New Zealand, you'd have learned yet another different way of pronouncing words. Now, if you learn a new language later in life, your pronunciation of words will be affected by the types of sounds that occur in your native tongue. You'll have extra difficulty if the new language uses sounds that your native language doesn't, and you'll probably end up changing certain sounds in the second language to match common sounds in your native language.
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How do accents develop?
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Naturally, as we are raised, our mouths begin to form so that we communicate comfortably with the vowels and sounds we’re used to. But when we’re confronted with a different environment with a different language and set of linguistics, our mouths struggle to perfectly imitate the sounds, thus, the accent is created
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Why does hair seem to get reset by a shower? (i.e. when I get out of bed and my hair is messed up, I can't straighten it manually, a little water doesn't work, but a full on shower resets everything to normal)
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Per an old-school shaving study (1930's), [Hollander and Casselman](_URL_0_) found that facial hair soaks up water and becomes flexible when it does so (quoted time on a page not available to non-subscribers is 3 1/2 minutes for warm soapy water, explaining why the splash isn't enough). This will allow a hair that is bent to relax into whatever state you want it to be. Since beard hair is just thicker hair, it can be inferred that regular hair does the same. When you get out of the shower, surface tension causes the hairs to stick together as they begin to dry out, allowing your hair to 'reset' or just set into whatever position you comb it into.
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How does grass seemingly survive being smothered by a snow blanket for the winter months?
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Most plants that live in areas where it gets cold enough for snowy winters store energy in their roots in form of starch. This way when spring kicks in they have a reserve of energy to sprout new leaves to replace the ones that died from the frost.
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Are plants more efficient at collecting solar energy than our current solar panels? If so, how much, and would it be feasible to collect energy from these plants without killing them?
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_URL_1_ They have 3-6% efficiency which is rather low compared to current solar panels which have an efficiency of around 20%. The normal way people harvest it is by growing biofuel plants and harvesting them and making them into ethanol. _URL_0_ There are other less well tested methods.
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Why do people have different but constant sneezing patterns?
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I was hoping to come here for answers but it seems like I may add to your question. What also makes us 'fight' sneezes. Most of the time I am about to sneeze but just Make the awkward sneeze face and weird noises but it just never comes out.
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How fast would a zebra have to run for it to look grey?
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An earlier thread with the same question had a pretty good answer: _URL_0_
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If all Animals and Plants are living beings,when the first living things were born millions of years ago,was there an Animal/Plant who was both?
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It probably helps to look at a phylogenetic tree of life such as [this one](_URL_1_). Yes, plants and animals do have a common ancestor - at one point, a cell divided and one half would go on to become the ancestor of all animals (along with fungi etc.) and the other half to become all plants. However, it's wrong to say that it was an animal that became a plant, or that it was a plant that became an animal. As u/Gargatua13013 points out, this thing lived approximately 1 billion years ago - it would have been a very simple, single-celled organism that would not meet our definition of a plant or an animal. Instead it would probably have been similar to extant protists such as these ['basal eukaryotes'](_URL_0_).
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How does hair hold onto water so well?
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Like tree capillaries your hair forms tiny channels for the water to coalesce via cappilary action. This keeps the water spread out and away from the body heat of your head. This prolongs the process of evaporation.
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If space is frictionless, why is the limit on how fast our rockets can go so close, wouldn't a big enough rocket constantly accelerate?
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Okay, so fuel has mass. The more mass you add, the more thrust you need to move it, which means bigger engines and more fuel, which means more mass... All kidding aside, at a certain point adding more fuel becomes impractical. You have to put the fuel in a container, add more structure to the ship, etc, etc. You are somewhat on the right path though. Yes, a rocket in space will accelerate, so long as there is thrust. When the fuel runs out, in theory it will maintain whatever velocity it was at when the engines shut off. There's been a puzzling issue with the pioneer probes in that there was a deviation in the calculated velocities of each probe. _URL_0_ Before I get downvoted for not including a ton of differential equations, the OP did request a "simple" explanation.
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If smell and taste are so closely related, then why do many things that smell good taste bad? (e.g. soap, perfume, lotion)
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Because the scents in soap, perfume, and lotion are added in. They are mixtures of extracts from plants. The plain soap by itself is horribly bitter tasting. If you eat it, your tongue will sense that bitterness while your nose registers the pleasant odor. It would be like adding the same scents to dirt and eating it. It will still taste like dirt but now in spring breeze.
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Is there any way to remove the tar in smokers' lungs?
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You have gajillions of tiny cilia in your lungs that are continually sweeping stuff out of there. Takes 18 to 24 months to get them clean, but even non-smokers have crap in their lungs if they live in the city.
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Can lungs be cleaned from tobacco tar?
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Probably not. I've dissected plenty of humans. Anyone who smoked or lived in a city has some black shit in their lungs. The macrophages, specialized cells whose job is to consume foreign material that makes it into the body, eat up the tar and pollution and store it on the lung periphery. Smokers have patches of the black stuff on the outside of their lungs, even if they didn't get lung cancer.
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Why do plant cells contain both chloroplasts and mitochondria? Couldn't the cells use energy from chloroplasts alone?
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Contrary to the answers below ATP **is** produced within the chloroplast. ATP synthase is located in the thylakoid membrane/space and does make use of the proton motive force generated by either cyclic or non cyclic photophosphorylation. But - the ATP produced in the chloroplast just isn't enough to compared to the amount produced in the mitochondria. We move relatively minimal numbers of protons across the membrane during photosynthesis - the really important product of non-cyclic photophosphorylation is the generation of reducing equivalents (NADPH). This can then be used to fuel the Calvin cycle and the production of triose phosphates and sugar derivatives. Once we have produced TP/sugars, these can be metabolised to produce NADH in the mitochondria. The proton motive force produced by the electron transport chain is considerably greater, and much more ATP can be generated than relying on chloroplasts alone.
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If chloroplasts make ATP AND synthesize sugars, then why do plants need mitochondria even when growing in the light?
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ATP is an extremely short storage type of a molecular. However, sugar (and I'm talking about starch here) can be stored for a very long time without much trouble. Once the plant needs the energy the starch gets converted into sucrose to supply all the energy needs. And even more basic - what would plants do during the night were it not for mitochondria.
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Can animals really sense earthquakes and other natural disasters before they happen?
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We are not talking about days before the event, not hours, maybe minutes, but normally seconds. _URL_0_ Is a good example (still this might be some coincidence) My theory is that some of those sound waves travel slightly faster through the ground than the earthquake itself due to some ground properties. I know that sound always has the same speed in specific materials, but maybe there are layers of harder stone in the ground which transmit the wave faster, but not that intense. Dogs have far better ears and are more sensitive with their paws, so they are warned earlier. I also noticed a similar event a few days ago during a thunderstorm. Ive been in the basement when I first heard and felt a minor noise, one or two seconds later the actual thunder arrived, because air transmits sound slower than the ground and the lightning probably hit somewhere in a close range.
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Is it possible to perform not an organ transplant surgery, but an organ implant surgery?
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Strictly speaking, we already do implants! Kidney transplants usually just leave the original failing kidney in place, leaving patients with an awesome 3 kidneys. Though not stem cells, artificial hearts have been implanted to replace a failed heart. Dick Cheney famously had this procedure, and for a long a while had 0 pulse. Now he has a fleshy heart, though. In regards to redundant organs, the closest thing I can think of are vestigial structures. Many provide a minor boost to whatever system, though are not vital to function or life. Redundant organs are really a sci-fi trope, and anything regarding them would be pretty much conjecture. Perhaps posting to /r/asksciencediscussion would get some answers in.
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If the gene for having six fingers is a dominant trait, why isn't it more common in the world?
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It is possible to be both rare and dominant, it's just that the rare people don't easily overtake the population. The only reason why it would be very frequent would be if people with six fingers mated more frequently or effectively, were fertile longer, or were sexier...
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If having 6 fingers is considered a dominant trait, why do most humans have only 5?
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There are several different mutations that cause polydactyly, and most are dominant. It’s just so very rare in the gene pool you hardly ever see it. In addition in modern times, I suspect cosmetic surgery early in life does a good job at hiding such genotypes.
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Do orgasms feel the same for men and women?
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To guide this discussion a bit: we can talk about the amount of chemicals in each person's body, as _ pH_ expertly did, but you're asking a qualitative question. Orgasms feel different between different people based on their physical/psychological status (see: why some women can't orgasm whatsoever, whereas others can get there in seconds), and the chemicals involved in the orgasm will have different effects in different people for reasons more involved than just male vs. female physiology. In short, there's no way to truly answer your question in a qualitative sense beyond anecdote, and the quantitative in this sense doesn't shed terribly much light on the qualitative answer you're seeking.
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Is there any evidence that men and women feel the 'same sensation(s) of pleasure' during sex, and specifically during orgasm? Or might they be entirely different sensory experiences?
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If you believe transgender people, the answer seems to be that they are different. The best evidence I've heard is reports from transgender people who go on hormone therapy that the way they experience sexual pleasure does change. Julia Serano has a PhD biochemistry and molecular biophysics, and in her book Whipping Girl, she talks about her orgasms becoming something that she felt in her whole body and her sex drive becoming less visual and more sensation driven. She admits that it is just her documenting her own experiences so it isn't super scientific, she did try to do her best being impartial in the documentation
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Does an insect, like a fly or a mosquito, have itches?
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Yes, if their exoskeleton gets irritated. (Itch: An uncomfortable, irritating sensation that creates an urge to scratch that can involve any part of the body.) For example, put a drop of formic acid on a cockroach's abdomen, and it will rub the area with its legs to clean it as it's irritated.
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Are there any stars travelling around their galaxy at relativistic speeds?
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The SO-2 star near the supermassive black hole in our galaxy, [trajectory seen here with error bars](_URL_0_) orbits at up to 2% the speed of light. To my knowledge this is the fastest "macroscopic" object relative to some reasonable rest frame. Neutron stars can rotate much faster about their axis.
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Would an object travelling close to the speed of light experience friction due to the hydrogen in space?
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Absolutely. However the intergalactic medium is so thin that the main obstacle is actually the cosmic microwave background, which dominates collisions with protons. In this recent paper [here](_URL_0_) the interaction of a relativistic spacecraft with the redshifted CMBR is studied and it is found that a gigantic amount of energy is lost to "friction" and emitted with a very characteristic signature. This by the way allowed to place constraints on the possibility of alien spacecraft traveling relativistically anywhere close to us.
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What happens when car brakes release their gained heat energy into the air and it dissipates, is that not destruction?
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Why would you consider that energy destroyed? The dissipated heat *is* energy, and it doesn't disappear. You can write an equation for the conservation of energy in this scenario and it will just tell you that, in the simplest case (car is not turning or going up or down a hill, and it is stopped entirely due to the friction between the brakes and the drum), the heat lost due to friction must be equal to the change in kinetic energy of the car. This heat will go into increasing the temperature of the drum/break system but it is in no sense destroyed. However, friction is not a *conservative force*, which means that if you were to run the process in reverse you wouldn't get that lost energy back. Perhaps you are confused about the difference between energy being lost in a non-conservative process vs. energy physically disappearing.
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Is there a physical constraint (as opposed to technological) on maximum telescope viewing distance or resolution?
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The ultimate physical constraint on telescopes is diffraction. Due to diffraction, the best resolution is proportional to the ratio of wavelength observed to aperture size. Note that this just places limits on individual telescopes depending on aperture size and does not mean that there is one fixed limit for all telescopes. In principle, you could get ever better resolution if you built ever bigger telescopes. While a telescope the size of our solar system could in principle see with far better resolution than we currently have, such a feat is currently technologically unattainable.
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Why doesn't hair that falls off our body decompose?
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Hair is mainly the protein keratin (same as finger nails) and is both tough and insoluble, which means it doesn't dissolve in water. This leads to the relatively long decomposition time when compared to soft tissues. [Here](_URL_0_) is some detailed information on hair.
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How is thinking different once a person learns a language vs. before language was invented/when they were an infant?
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Most of early learning involves repetition, that is, multiple exposures to behavioral relations in the environment. For example, a baby can observe that when his/her mother cheers when he/she babbles thus increasing the likelihood that he/she will babble again, and eventually the baby's babbles will be shaped into more recognizable words if he/she is capable of language. More language essentially streamlines learning.
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How can light photons have momentum?
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While **p** = *m* **v** is the way we calculate momentum for human–scale lumps of matter moving at human–scale velocities, but that's not what momentum “is”. Momentum is the quantity which is conserved because the physics describing how a system behaves does not change if that system is merely displaced (without rotation) from one location to another. Photons carry some of this quantity.
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Carbon in all forests is 638 GtC. Annual carbon emissions by humans is 9.8 GtC (1.5% of 638). Would increasing forests by 1.5% effectively make us carbon-neutral?
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The processes of removing CO2 from the atmosphere and storing it are called "capture" & "sequestration". Growing more trees is one of the easiest ways to capture CO2, but even if you manage to increase the Earth's biomass by 1.5%, you then have to worry about maintaining biomass at that higher level. It's easy for a catastrophic event like a forest fire to release that carbon back into the atmosphere at a future date, so forests are a poor form of sequestration. There are proposals to store significant amounts of carbon underground through "geological sequestration" (dissolving CO2 into deep-underground salty brines or permanently incorporating it into carbonate rocks). That's a better form of sequestration, but the "capture" part is more difficult in that scenario.
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Why is that something like a potato chip gets soft when "stale" but something like a slice of bread gets hard when stale?
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Good bread is moist. Good chips are extremely dry. They exist at outer edges of the bell curve of humidity. Because of entropy all things tend towards homogeneity, so the very dry will become more moist and the very moist will lose moisture to the air, until air, bread, and chips are all hanging out at a similar level of moisture. This is for the same reason that, when placed in the same room, a glass of boiling water will cool while an identical glass full of ice cubes will melt. They are trending toward an average state of being.
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Is light not capable of having shorter wavelengths than gamma rays, or longer wavelengths than radio waves?
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we simply call any/all EM radiation whose wavelength is less than about 10 picometers "Gamma Radiation" and any EM radiation whose wavelength is longer than about 1mm or so. There is occasionally a distinction for EM waves whose wavelngths are in the millions of meters long.
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What do prime numbers in other bases look like?
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As others have said, the definition of a prime number is independent of the base it is written in. But... determining whether a number is prime or not can be tricky, and it seems to me that your question is more centered on this task rather than the definition of a prime number. We have a number of rules for determining whether a number written in base 10 is divisible by a given small number, e.g. x is divisible by 2 exactly when the last digit of x is a multiple of 2, x is divisible by 9 when x's digits sum to 9, etc. These rules can often ber used to determine that a number is not prime. In other bases, what would these rules look like? [Here's a start](_URL_2_). [Some discussion on StackExchange](_URL_2_). Hopefully this gets you started.
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Why does a container of liquid gas not cause the outside of the container cold?
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The gas only cools down when it expands. It remains at room temperature when in the liquid state.
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What determines the color of meat?
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Red meat is typically made of slow-twitch muscle fibers, or at least a higher percentage than white meat. Chicken breast is a muscle used for high intensity, low duration work (hopping up to roost). Compare that to duck breast, which is used for longer term "cruising" effort. The actual red color comes from the protein myoglobin, which acts like an oxygen storage system in muscles. Essentially, white meat is used for anaerobic bursts of effort, red/dark meat is used for endurance. It's especially noticeable in marine mammals, whose meat is very high in myoglobin (store oxygen for diving) and very dark.
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I’ve read that plastic slowly decomposes over about 1000 years. What exactly causes it to decompose over such a long period of time? Why doesn’t it just never decompose?
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Polymers tend to be very stable, but certain factors will break them down. Exposure to acids/bases, UV light, oxygen, etc are all things that have the ability to break up the bonds within a polymer. The issue is this happens very slowly in most cases and is the reason why it takes so long, but it does still happen.
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Why is it that when a microwave heats up food, some parts of the food come out completely cold, while the others are incredibly hot?
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The microwave primarily heats polar molecules (such as water) in the food. If the moisture content of the food is not homogeneous, the heating also might not be. Also, the intensity (power) of the microwaves vs position in the chamber can vary quite a bit. Newer microwave ovens use a couple of techniques to help deal with this. One is a turntable, to move food through the chamber as it is heating. The other is a reflector (a fan) to "stir" the microwaves.
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Does opening a dryer partway through the cycle help clothes dry faster?
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Don't bother, modern dryers use fans to move air through an intake (dry air which passes into the tumbler) and outtake (moist warm exhaust). Your dryer would be awful at its job if it just heated up your cloths, the water would have nowhere to go.
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How do spiders build webs between 2 poles, with no where to hang from above?
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It varies from spider to spider, so I cant speak to all families. I do know some about orb weaver spiders from personal observation. They start by creating a horizontal anchor line between two points, by ejecting a type of light very sticky silk in the same direction as the wind. When this anchor line is attached to the other side, the orb weaver will cross reinforcing that first line with a different type of silk. [David Attenborough describes the process in detail here.](_URL_0_)
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If our Universe is expanding and assuming it's infinite, is there a maximum distance we can reach/observe?
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Have a gander at this, seems exactly what you'd be interested by - I was. _URL_0_
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Has the universe always been flat?
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As the Universe expands, it deviates from flatness. So if you start off with a universe that is barely not flat, it will quickly become VERY highly curved. So we go out and measure that our Universe is [extremely close to flat](_URL_0_). This means it must have been yet closer in the distant past. How is that possible? Why would we expect the Universe to be so finely tuned? This is the famous [flatness problem](_URL_2_). There's a loophole to the rule I mentioned in the first sentence. If the expansion of the Universe is accelerating, then it will actually approach flatness over time, rather than run away from it. This is one of the original motivations for [cosmic inflation](_URL_3_), a period of accelerated expansion in the very early Universe which would start off with generic initial conditions and leave the Universe very nearly flat. This is closely related to a discussion we're having at [this thread](_URL_1_), by the by.
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Why can't we see well underwater? What is different about the eyes of aquatic animals?
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The key difference is in the lens of the eye that handles focusing the image onto the retina. When focusing, the "work" is done as light transitions from one material to another, as the index of refraction changes, which causes the light to bend. Outside the water, this is (roughly) air - > lens - > vitreous humor (the fluid in most of the eye). Underwater, the air is water instead, and the difference between the index of refraction of air and the material of the lens and water and the material of the lens is much greater. So outside the water you need a much less round lens to do the focusing. Human eyes are adapted to focus well in the air, while the eyes of aquatic creatures do better under water. This is also why if you put goggles on, you can focus well underwater.
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Is it possible for the asteroid belt to eventually produce a planet?
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No. Currently the relative speeds between asteroids is too high. When asteroids hit each other they tend to break each other up rather than combine. These too-high speeds result from migration of Jupiter and Saturn. Also note that there is currently very little mass in the Asteroid Belt. The total mass is about 4% the mass of Earth's moon. The largest asteroid, [Ceres](_URL_0_), makes up about a third of that mass.
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[Computing]How necessary is it to eject USB drives before removing them?
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Annoyingly, modern versions of Windows mark removable drives as "dirty" when they're plugged in and only remove the mark when you "safely remove" the drive. When you plug in a drive with the "dirty" mark, Windows pops up that "Do you want to Scan & Fix?" dialog box. Clicking the "Scan & Fix" button *should* be harmless, but seems to be buggy enough to have a reputation for ruining seemly-good filesystems and eating all your data. It's probably worth getting into the habit of doing the "Safely Remove" dance just to avoid any potential problems with the "Scan & Fix" misfeature.
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What happens when I take a USB drive out without ejecting?
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It's a technical equivalent of walking up to a scribe and just stealing their paper. Most of the time they're not writing and everything is fine, sometimes they're midway through a paragraph and the information turns out a bit wonky (files in inconsistent state, filesystem with freed or double-committed blocks) and very occasionally they're writing at that time and you get the software equivalent of a pen strike across the paper (corrupted sector, checksum failures, file table corruption).
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Is there an estimate on the size of the universe vs the size of the observable universe?
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The size of the total universe is at least 250 times the size of the observable universe. Citation: _URL_0_ This might be a bit more accessable: _URL_1_
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When you whisper, are you still using your vocal cords?
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Nope! When you're whispering, you're generating the sound without using your vocal cords -- people with laryngitis who can't talk normally are still able to whisper. The sound is produced by air turbulance in the larynx instead of the vibration of the vocal cords. There may be some slight vibration there, but it's not necessary for sound production.
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When we whisper, are we using our vocal cords at all? And if not, how can we still make out vowel sounds?
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Vowels are distinguished primarily through different frequencies created by the shape of your oral cavity (your mouth hole). If you look at [spectrograms of different vowels](_URL_0_), you can see these frequencies coming through. The important feature of vowels compared to consonants is not that the vowels have vocal cord movement; many of the consonants do too. The important thing is that its a generally uninterrupted flow of air. The manipulation of this flow of air is what makes the different vowels different. Even without vibrating the vocal cords you can still make these shapes, and while they will be quieter than if you're speaking normally, they'll still be easily detectible by the listener. **edit:** And yes we still use the vocal cords when whispering. See /u/redrightreturning's comment for the details.
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Variations in the ozone layer seem to be cyclical, now reaching its thickest point in 10 years. Should we expect the layer to slim down again in the following years, making the ozone hole reappear?
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There is a natural variability in the ozone layer, caused in-part by fluctuations in temperature. Like any other geophysical system, there is a large amount of noisy variability on top of a physical trend. The ozone hole will be larger some years, smaller in others, but on average it is returning to its historical state as we have curtailed activity that was eroding ozone.
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What exactly happens when someone dies of "old age"?
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There usually a 'detectable' illness or medical condition but there can be more than one. For example someone might have long-term kidney failure, heart failure and lung disease for years that eventually result in their death one day. Alternatively they could have Alzheimer's disease that predisposes them to pneumonia. On the other hand most of these illnesses are the result of degenerative processes and the frailty that comes with old age. Sometimes you could identify the mechanism of death but it might distract from the fact that they were already going to die soon. So people do die from the ageing process but not really just from "old age".
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What actually happens to a person when they die of "old age"?
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[Old age](_URL_1_) is not a scientifically recognized cause of death any longer. The specifics could be any number of individual things, there is always an underlying disease process of some sort though. If it is cardiac disease then [ACS](_URL_2_) is the most likely cause. Heart attack is another classical term that is not used anymore. It's been replaced by many terms depending specifically on what happens, but ACS is one of the common ones. The heart in and of itself is unlikely to 'stop' naturally if everything around it works well. There are several conduction diseases like [WPW](_URL_0_) that can cause the heard to stop beating, but since every cardiac cell has the ability to initiate a heartbeat without a specific conduction illness the heart isn't going to stop beating without some other cause.
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Is it possible to have a Pi amount of some object, or would it be infinite?
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Start your car. Accelerate from 0 kph to 20 kph. Somewhere along the way you'll be going pi kph.
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How can the North Star appear fixed from any other view point on Earth other than the North Pole?
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When you are on a merry-go-round and you look at the central pole, it's always in the same position relative to you. The same principle applies here. Polaris is on the imaginary line around which the Earth spins. And the earth is just a very large merry-go-round, so it behaves exactly as expected.
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Are lunar and solar eclipses more likely to occur in pairs?
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Yes, that's pretty much right. Lunar and solar eclipses can only occur when the Earth, Moon, and Sun are in line with each other. Which only happens when the Moon's orbit around the Earth is basically edge-on to the Sun. And when that happens you have a pretty good chance of the Moon ending up in the Earth's shadow and vice versa, or lunar/solar eclipses during that lunar orbital period.
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Has recent research found any ill effects from prolonged exposure to radiation from cell phones?
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No. There is no plausible mechanism consistent with the laws of physics by which the electromagnetic radiation emitted by cell phones could cause cancer. The photons radiated by a cell phone are much, much too low in energy to ionize DNA or other biomolecules, which is how DNA is damaged by X-rays and similar high-energy electromagnetic radiation. It seems that once an idea like this is planted in the public domain (cell phones cause brain cancer, vaccines cause autism), it is impossible to stamp out completely. Even when it is silly on its face (cell phone radiation cannot cause cancer) or becomes so (there is no longer thimerosal in the vast majority of vaccines).
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Is it possible to have planets orbiting a star in significantly different planes, similar to the Rutherford atomic model but with the star as the nucleus?
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Planets follow the disc orbital paths because they form along with the parent star from the same rotating and flattening cloud of gas and dust, so it would be unlikely to find a naturally occurring planet on a different plane, unless the said planet didn't form with the original star (i.e. it's a captured planet, possible a rogue planet that wandered into the existing system). There's nothing, afaik, physically preventing differing orbits besides the origin though, so I could buy a sci fi scenario where a sufficiently advanced race purposefully creates a Rutherford atomic model style solar system by manipulating planetary positions.
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Why do bugs fly around in circles? It seems like a waste of energy to me...
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It's our fault. A lot of insects use the moon as a form of guidance system. If they want to head in a constant direction they keep the moon at a constant position in their sight. This should result in straight lines. Unfortunately for them we invented electrical lighting. You might notice the circles they are rotating in, perpendicular to the centre of this circle will be a light. It's because they think that light is the moon, and they are trying to go in a straight line. And failing.
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Why does it seem there are more big storms at night?
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Most of the time it's because thunderstorms don't start forming until well after the peak heating of the day occurs (typically around 2pm or so), because that is when the atmosphere is the most unstable and contains enough energy to break any capping environment. Well-developed storm cells with steady surging cycles tend to 'feed' off of this heat energy and can persist into the late evening and night time hours. This is why you typically don't see thunderstorms in the morning, although if a frontal boundary is nearby, that would be enough to maintain the needed instability around the clock for thunderstorm formation to occur. Hope that helps.
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Are rainstorms, or storms in general, at all influenced by the sunlight? In other words, do storms behave differently at night vs during the day?
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In Arizona during the monsoons there will be thunderheads that form during the afternoon. The heat of the day helps to form the anvil shape as thunderheads need strong convection currents and the heat creates the necessary lift. These convection currents, in turn, move water and ice (hail) through the cloud and create static electricity which allows for the lightning. The moisture that falls pushes further northward and can fuel the creation of another thunderhead to the north. This repeats creating new storms until the energy dissipates.
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Why is earths gravity so similar to saturn (relative to other planets) when its only a fraction of the size, when the gravity on mars is close to a third of earths when its so much closer in size?
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Because gravity is a function of mass over radius squared, so whilst Saturn is much more massive, it is also much larger, so the surface gravity is the same. Because the Gas Giants have very dense cores, but very sparse, thick gas layers, at the surface you are far away from most of the mass. With Mars, it's a similarly rocky and dense body to Earth, but smaller. Mars' radius is 0.5 Earth radii, but its mass (since M=4/3πr^(3)ρ(density)) is only ~0.1 Earth masses.
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If light photons have no mass, how can a black hole exert a gravitational force on them?
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Because gravity isn't *actually* a force that acts between two massive bodies (though that's a very good approximation, for the most part). It's what happens when mass and energy curve spacetime. When spacetime is curved, anything that tries to travel on a straight line will end up on a curved path, and we see that curved motion (through space *and* time) as gravity. So photons are affected by gravity simply because they, like everything else, live in spacetime.
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Does filling a dishwasher with less dishes make them cleaner?
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The fact is that soap is "used up" when it removes the various lipids from your dishes, so probably having less dishes will mean more soap to go around and therefore probably cleaner dishes. Probably cleaner, because the soap manufacturer may have already put enough to go around(although highly unlikely)
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Does sleeping with a fan on in your room damage your hearing over time?
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Some research being put together by my lab on noise-induced hearing loss is suggesting that there is no 100% "safe" prolonged noise exposure, even at seemingly harmless amplitudes. Now, whether or not you will have significant hearing loss (that's a *really* broad term) is a different, dynamic, and highly-individualized question altogether that can only be accurately assessed later on in your life; however we are working to predict hearing damage that occurs based upon such factors and amount of exposure. It's hard to give you a definite yes or no answer, and it is possible that such noise exposure can lead to negligible hearing damage, but this is not entirely clear at this point.
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Do most solar systems in the galaxy rotate on the same plane as the galaxy? If so, why would that be the case?
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As far as I know, that is most definitely not the case. Star systems are randomly oriented every which way. For example, the star Vega is almost completely on its side with respect to the Earth, and when we view it we are seeing its north pole almost head-on. Other star systems (especially ones we have discovered the exoplanets of) are oriented in random ways such that planets orbiting them cross over the star (and thus we can use the transit method to detect their planets). But from what Ive read there is no rhyme or reason to star system orientation and they are all randomly oriented.
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Is aging considered a disease? And other aging-research-related questions
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Aging is not a disease specifically but it is a risk factor for many things. Diseases are considered as processes which take place abnormally leading to a set of symptoms and signs, since aging is not actually 'abnormal' it is not a disease. There is not much research for aging in itself however the majority of diseaes which people get tend to happen later in life and as research helps to treat these you will find that life expectancy increases.
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Does the moon have tectonic plates or is it just one big rock?
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No it does'nt - the Moon does not have active plate tectonics or anything resembling active plate spreading, in fact that is one of the reasons lunar craters are so numerous and so well preserved: the crust they are developped on is never recycled. The reason plate tectonics did not take off over there is mainly because the crust is thicker, the mantle drier and deeper. You can find more info about basic lunar geology and processes here: _URL_0_
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If alcohol is lighter than water why do the bottom of alcoholic drinks taste the most alcoholic? (Read: worst)
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Ethanol is less dense than water on its own, but it is *soluble* in water so that when they are mixed it does not separate out like, say, oil. Since it is soluble, the two together essentially become a new "unified" liquid and the relative densities do not cause layering (like how dissolved salt or sugar does not separate out by density either). If I were to guess at what you are experiencing, it would be that you have ice in your drink, and the part at the top has simply been diluted more locally due to the melting ice.
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Why can humans not digest hair, which is made of many amino acids and so (one might assume) contain valuable calories and nutrients?
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It has something to do with the many disulphide bonds found in hair keratin. You either need a strong base to break them, or a specialised hydrolyse. While the small intestine is slightly basic (8 to 9 pH) it's nowhere near as strong as it needs to be in order to hydrolyse those bonds. Not to mention, the keratin found in your hair is very tightly packed, therefore, it's hard for hydrolyses to break the disulphide bonds down. There are some animals which can, mainly bugs, but they feed on carcasses and play a crucial part in decomposition.
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How would one go about terraforming the moon?
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It doesn't have an atmosphere so it wouldn't be possible.
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Would it be possible to terraform the moon?
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Yes, the possibility is not prohibited by the laws of physics. No, it is not even remotely possible within the foreseeable human future. Terraforming implies changing the existing environment to a more desirable one. The problem is the moon has no atmosphere to work with. So you'd need to start by creating an atmosphere, but the atmosphere would be stripped off by solar winds faster than we could ever hope to generate it. We would need to create enough mass to hold an atmosphere, somehow generate a protective magnetic shield, and import in enough desireable elements to create the atmosphere. So yeah, it's possible. But no, not really.
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Can organ recipients donate organs?
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Usually they only redonate an organ if the first recipient died shortly after receiving it - I don't know exact specifics, but it would be a scenario in which the organ was transplanted in a last ditch effort to keep someone alive that failed, which I think is at most a few weeks. I looked at some papers real quick and they were all 10 days or less. Most of the time the organ is damaged too much in the process of transplantation, spending time in the body of someone with a disease that damages said organ, and just general organ damage from death.
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Question about Photographic Memory
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First off, eidetic memory was originally used to refer to the more common term "photographic memory" however now eidetic memory more generally references any "exceptional" memory ability and is a really poorly defined term these days. Secondly, actual "photographic memory" is a very controversial topic as there is yet to be very strong evidence that true "photographic memory" actually exists as it is described in popular culture. I won't go so far to say that it *can't* exist, but I'm very skeptical. So, with that said, I'm not sure your question still stands as there is no firm evidence of photographic memory.
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Why is hardly any oxygen and nitrogen found in crude oil if it was formed from biomass, which contained significant fractions of these elements?
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Good question! The oxygen in biomass is mostly (but not entirely) from the water that makes up 70%+ of most any marine organism's biomass. As kerogenic sediments decay under oxygen-poor conditions, the water is gradually expelled as the sediment settles, and what little free oxygen there is rapdily metabolized by bottom-dwelling bacteria. Nitrogen tends to either get rapidly metabolized as nitrates, or float away if it's as elemental nitrogen gas. What's left are the hydrocarbons, which are very difficult for microbes to metabolize underanoxic conditions. Once the kerogenic sediments are buried and undergoing diagenesis, the pressure will tend to squeeze out the remaining water via the pore space in the rocks.
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Why does crude oil not contain organic debris like fossils, proteins etc?
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Petroleum is derived from microorganisms and the chemical processes that transform those microorganisms into petroleum (e.g. diagenesis, cracking, etc) effectively break them into hydrocarbon chains. There are a lot of places online you can read about the petroleum formation process, e.g. [here](_URL_1_) or [here](_URL_0_).
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If I could travel back in time, really really far back, would I be larger relative to the other objects in the universe around me because of the fact the universe is expanding?
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Your body is held together by the electrical forces between its molecules, and these forces override the expansion of the universe. Your body does not expand as the universe does. The solar system, galaxies, and galaxy clusters are held together by gravity and also do not expand as the universe does. This is one way we know the universe is expanding, because we can see the galaxies moving away from each other. As for time-travel-specific questions I have no answer, because as far as we know it is impossible.
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When the moon is visible during the day time, is there any measurable difference in brightness outside than when the moon is not visible?
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There is technically a difference, but I don't think it would be measurable. The sun provides about [1362 Watts of energy per square meter of Earth (W/m^(2))](_URL_0_). The full moon provides [about 0.0068 W/m^(2)](_URL_1_) of reflected sunlight to the Earth. That's [200000 times less energy](_URL_2_). And the other phases of the moon will obviously provide even less energy. To give you an idea of how insignificant this is: because Earth's orbit is elliptical, and because [the Sun's output is not constant](_URL_3_), the amount of energy we receive from the sun changes by a few Watts per meter squared over the course of the year, which is thousands of times bigger of an impact than the tiny amount of reflected light from the moon. Edit: clarifying units
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What happens to short term memory if you are in a coma for a long time?
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Going into a coma is a result of some severe stresses on the brain. Your brain shuts down. It is not at all like stopping a dvd, then starting it back up again. It's much more like taking a sledgehammer to the dvd player, and later hoping that disc remains intact. So, it's unlikely that you'd remember the number. In fact, if you were in an accident so severe as to cause a coma, it isn't very likely that you'd even remember the *accident*. Often, patients won't even remember any of the events leading up to the accident. Many of my patients lose hours and hours of pre-accident time after waking up from their comas.
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Why does asparagus make your pee smell so different?
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Breaking down (metabolizing) asparagus is thought to produce sulfur containing compounds that are excreted in the urine, causing the smell. Sulfur containing compounds are infamous for producing unpleasant smells, not the least of which is the distinct rotten egg smell. Interestingly, only a certain percentage of the population can actually detect the smell. It's a trait I think about 20% of the population possesses. Edit - [Here is a link in support](_URL_0_) Looks like most of the studies on the issue are surveys, but they are published. Turns out a small percentage of people do not produce the smell in their urine and whether or not one can detect the smell is a separate trait. So this is no simple genetic system.
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How bad is it, really, to look at the solar eclipse?
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The reason she didn't feel any pain is because the part of your eyes that focuses the light lacks pain receptors.
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How much does adding chocolate to milk change the health benefits of milk?
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It just adds more calories which can be good or bad depending on the context
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Can a dwarf planet become a moon?
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Eris is too far away from Neptune to be affected by it much even when they are as close to each other as is possible. Even at the point of least separation, there's still something like 8 AUs distances of separation between the two. To compare: Earth and Jupiter get to about 4 AU of separation, Jupiter is more massive than Neptune, Earth is more massive than Eris, and half the distance means four times the force of gravity, so the fact that we aren't a moon of Jupiter right now is pretty solid proof that Eris won't become a moon of Neptune any time soon. However, what you are describing probably happened once! Neptune's largest moon Triton (slightly smaller than our own), is very similar in composition to Pluto, and rotates in a different direction than all of Neptune's other moons. For this reason, we consider it highly likely that it's a captured Kuiper Belt object.
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If electric motors replace internal combustion engines in vehicles, will we ever face an "ozone pollution" problem?
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Actually, there already is an ozone pollution problem. From [Wikipedia](_URL_0_): > Low level ozone (or tropospheric ozone) is an atmospheric pollutant. It is not emitted directly by car engines or by industrial operations, but formed by the reaction of sunlight on air containing hydrocarbons and nitrogen oxides that react to form ozone directly at the source of the pollution or many kilometers down wind. Also from the looks of it, at least on the Prius, the motors in use are fully magnetic (brushless), therefore they do not contain an ozone-producing spark gap. As long as the car doesn't have spark gap motor, it shouldn't produce ozone. However, if the electricity running the car came from a fossil-fuel source, even a fully electric car will have a significant carbon (and ozone) footprint.
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Why do small birds hop and not walk to move around?
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I am pretty sure someone with bird knowledge will expand but I read in a book that's their fear instinct kicking in. By hopping they are ready to fly away at moment notice since they spring themselves before taking off.
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Why does food, like pretzels and bread, go stale?
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Bread goes stale because of a phenomenon known as *retrogradation*, where the starch molecules align and crystalize. This binds water and leads to the firm, dry texture that we associate with stale bread. It's the same process that makes leftover rice tooth-crackingly hard. Hard pretzels are baked down to an extremely low moisture content to give them the crunch and crisp we expect. When exposed to a generally humid atmosphere, they will absorb enough water to begin retrogradation as mentioned above.
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Can an orbit be circular?
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For bound two body orbits, like you mentioned, the orbits are generally an ellipse, but circles are a special type of ellipse, which you can have for a specific orbital energy and angular momentum in the system. In theory, nothing forbids circular orbits, and it's often a useful assumption when doing simple calculations. For example, most of the planets in the solar system have very nearly circular orbits, with eccentricities around 0.01. In practice, orbits get screwed with by the gravitational pull of all the other bodies in the solar system, so even an ellipse isn't a perfect description. As the solar system evolves, the eccentricities of the orbits change slightly due to the gravitational effects of other planets, and the perihelion of the orbit precesses.
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How much fuel could you distill from 5L of 42 proof whiskey? Fuel being interchangeable with gasoline (assuming you had the mechanical know how to convert your vehicle to run on alcohol)?
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5L of 42 proof whiskey would yield 1.05L of 100% ethanol if you distilled it (in reality you can only distill it to about 95-96%, so figure a little bit more than that), which is usually diluted in an 85:15 ratio with gasoline. That would give you 1.235L of usable E85 fuel for a car that's equipped to run on ethanol.
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Is it possible to fuel a car with whiskey?
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The short answer is yes, as long as the whiskey's strong enough. The same alcohol in whiskey is the same type used as fuel, ethanol. In the US you can get a permit to make your own fuel alcohol which uses the same process as making moonshine. What separates moonshine from whiskey is whiskey is aged in oak barrels and dilluted to drinking strength. Now you're average whiskey is only 40% alcohol. In order to work in a car, it'd have to be upwards of 95% alcohol. So while its possible to run a car on high proof whiskey, your average whiskey wont be strong enough to get the job done.
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Why is water tasteless? Since our bodies need water, shouldn't they have evolved to enjoy the taste?
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taste didnt evolve to make us enjoy food but to help us distinguish what we are eating. If water had a taste you would be tasting it constantly, as your mouth is almost always wet. Water which is impure does have a taste which registers as either rancid, salty, bitter and so on.
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Is it true that a full tank of gas gets better MPG than when a vehicle has only 1/2 or 1/4 tank?
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By what mechanism would carrying more weight around cause you to get higher gas mileage? **Edit** Famousp's [response](_URL_0_) is great. I would also like to add, depending on where you are driving, due to the fact that the gauge is floating in the tank, the gauge can read that you have more gas than you did earlier due to shifting gas. They just aren't very accurate, and as a scientist I am very sad that one of the most used instruments in day to day life is terribly inaccurate. Hell on some cars your gauge can read *more* than full...
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If we are running out of helium, why is it still used to inflate party balloons?
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The helium "shortage" is simply from the decision to sell off the Federal Reserves within the decade. It, by no means, mean we're running out of it. Although helium is continually lost through atmospheric escape, it's also a ~~natural by-~~ derived product from natural gas production. Also, inflating party balloons is a very, very small percentage of helium consumption. Edit: For clarity.
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If the big bang happened 13.8 billion years ago, and that was when "Time" began, does that mean that 13.9 billion years ago doesn't exist?
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This is a bit confusing, but yes, that's how we think of time. It's not infinite, it has a point at which it began. Asking what was before the Big Bang is a pointless question, there was no "before" because there was no time. It's like asking you your life was a year before you were born. It wasn't, you didn't exist, and it's not even right to say that the world didn't exist to you - it's specifically you that did not exist. Just like time started existing with the Big Bang. Some physicists have said that time did exist before, but the Big Bang was like a big "reset", so no information is possible to obtain about the "before" part. Others come up with even more unusual explanations, like brane cosmology, in which essentially our whole Universe is just part of a larger structure (larger as in higher-dimensional). But if you accept the view that the Big Bang was indeed the beginning of everything, then there's no "before".
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What is happening when my nose clogs up?
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The reason your nasal congestion "never seems to end" has more to do with the swelling and inflammation in your sinuses than with mucus production. The allergic reactions you're having cause your sinuses swell, thus blocking the airways. Blowing your nose can help remove mucus, but it does nothing to decrease the inflammation (and can actually make it worse if you go overboard).
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Why does food you heat up in the microwave cool down faster than food you heat up in an oven?
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All heating sources tend to heat the outer layers of food first. Microwave ovens transfer heat into food much more efficiently than convection ovens, so food generally spends less time in a microwave. In a convection oven, the heat on the outer layers of the food has time to diffuse into the inner part of the food, resulting in food at a more even temperature. In a microwave oven, it is possible to heat the outer layers of your food to a similar temperature very quickly, but the inside of the food is cooler. When you take the food out, the outside layer is loosing heat to the environment and to the cooler inner part of the food, so it will cool much faster than food which is a fully uniform temperature.
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Do the contents of our blood have any affect on mosquitos after they drink it? Do drunk people make drunk mosquitos?
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I think the answer is, "[we don't know](_URL_0_)," but it seems that mosquitoes are more attracted to drunk people, than sober people, and according to the article I linked fruit flies do get drunk, but have a high tolerance. Same article also says, "Any liquid other than blood is diverted first to a separate digestive pouch where enzymes break it down. So it is likely the alcohol is neutralised before it hits the insect’s nervous system."
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Why are rain clouds grey and normal clouds white if they're both made up of water?
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Rain clouds are supersaturated, meaning they contain more water than the air can actually hold. The "extra" water falls to the ground as rain. This means there's more water which absorbs more light in a rain cloud than a normal cloud.
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The Universe is 13.7 billion years old, and the observable radius is 46 billion light years. How come we can see the object, from which the light traveled to us 46 billion years, and the universe is just 13.7 billion years old?
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When we observe material that is billions of light years away, we are observing it in its relative location at the time the light from that object started traveling towards us. It has since moved at a rate consistent with the expansion of the universe. Using its observable location as a guide, we can extrapolate it's current location, giving us a better idea of the true size of the visible universe. _URL_0_
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