title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"If I had an electric chain saw, and then accidentally sawed the electric cord, would I get shocked?"
] | [
false
] | null | [
"The short answer is yes, it is possible. In order to disable the chainsaw, you have to cut through either the live or neutral line. So there may be a brief or sustained period where the chainsaw housing becomes live.",
"However, there are simply too many variables to be able to say whether you would receive an e... | [
"I was also going to state that most electric tools are double-insulated.",
"Last summer, I sliced into the cord while using an electric hedge trimmer. There was a loud spark. However, all of the contact points to the tool for my hands were plastic. I stopped using the cord, repaired it, and no permanent harm w... | [
"What are the handles made of?",
"I have a Makita 16\", 110-volt electric chainsaw, heaviest they make. It is double insulated meaning entire outside case is plastic, with an electric-isolated steel cutting bar. Unless touching the cutting bar (you wouldn't be), you won't be shocked when saw chain slices through ... |
[
"why can't I see the edge of my eye sight?"
] | [
false
] | null | [
"The only area in your field of vision that you actually can't see anything is where the optic nerve exits the eye as there are no photo receptors at this point ",
"here's the wikipedia article",
".",
"Your peripheral vision mainly consists of ",
"rods",
" (a photo receptor) that are more sensitive than "... | [
"Its important to remember that what you \"see\" is really a mental map of your surroundings, created and maintained within your brain. Its a composite image of vision, memory, guessing and cheating. "
] | [
"Adding on to what I edited, the map of of the environment and what you perceive is also combined with your bodies knowledge of where it is in space, also known as ",
"proprioception",
" (even if you can't see where your body parts are, you know where they are). As to how these things are combined in the brain ... |
[
"When I'm done baking something, should I leave the oven door open or keep it closed for the most valuable contribution of heat to my apartment?"
] | [
false
] | I live in Vermont. It's usually cold and I'm usually thinking about heat conservation. Here's the scenario: I turn the oven off, take my food out, and start wondering about whether a closed oven will leak heat evenly over time, or if some of that heat is being lost, in which case I should leave the door open to get tha... | [
"What you're looking for are fairly fundamental principles called the Laws of Thermodynamics. You should be able to find a short summary that can explain them better than I can."
] | [
"Right, good point. However, if the back wall of the oven is part of the apartment, this might not be a problem. \nIn this case, it would make sense to keep the oven closed. Energy transfer to the outside of the apartment is depending on the temperature gradient. Hence, if the oven is closed their will be a smaller... | [
"Right, good point. However, if the back wall of the oven is part of the apartment, this might not be a problem. \nIn this case, it would make sense to keep the oven closed. Energy transfer to the outside of the apartment is depending on the temperature gradient. Hence, if the oven is closed their will be a smaller... |
[
"Is it possible to have a B of around 5 T in a magnetic core?"
] | [
false
] | I've been conducting some research in the area of food engineering for sterilization of fruit juices. One of the non thermal methods is having an oscillating magnetic field, but we need to have big fields. I was wondering if it would be viable by this method, or the N*I needed would be way too big. | [
"5T is pretty extreme, but it really depends on what area you want. Magnetic field energy density is u=b",
" / (2*uo), which is 1e7 J/(m",
" at 5T in air. Then it really depends what frequency you need to oscillate your field at. If you want to vary your field at 60Hz in a 10cm cube, your energy is 1e4 J and yo... | [
"In practice, magnetic fields this large are generated with rare earth permanent magnets or superconducting currents. To estimate magnetic field for a regular coil, an ideal solenoid produces an axial magnetic field of B = (4 * pi * 10",
" ) * N * I T. If you have 1 turn/cm, then you still need a current of 100... | [
"Air core for the win. Adding a core material will put all the magnetic energy in the core, not in your juice."
] |
[
"Has obesity directly been shown to cause health problems?"
] | [
false
] | null | [
"Obesity increased cancer risk by 50% in a prospective trial, and is estimated to account for ~17% of all cancer deaths in the US - ",
"link",
".",
"Obesity increases the risk of ",
"heart attacks",
".",
"Obesity is strongly related with type 2 diabetes, which also increases risk of ",
"heart attacks"... | [
"The cause-effect relationship between obesity and health problems is complex. Plenty of narrow and uncommon issues can be caused by obesity, but there are two major ones:",
"Higher Blood Pressure",
"Blood Clots",
"Because obese people have more vascular veins in their body than if they lost weight, it requir... | [
"Your point certainly has some validity, I'm not sure why you are being downvoted so heavily.",
"Obesity is a complex, metabolic disorder. As a result, we don't always have a direct mechanistic understanding of how obesity leads to certain conditions. We are starting to get a sense of the biochemical links betw... |
[
"Is the sun capable of running on any kind of material or is it specific to hydrogen?"
] | [
false
] | I've been thinking for my entire life that the sun can only be made out of hydrogen, however, there are a few science articles on the internet stating that the sun can be made out of any material with little to no difference compared to the sun now. This is one of the article btw: | [
"The sun is fusing hydrogen to helium right now and has trace amounts of other elements from the original solar nebula. In about 5 billion years so much hydrogen would have been converted to helium that hydrogen fusion will stop and the sun's helium core will collapse under gravity increasing temperature and press... | [
"helium can fuse to carbon. The higher temperature causes the outer layers to expand into a red giant. ",
"No, this is a common inaccurate statement about stellar evolution. The red giant phase does ",
" occur at the beginning of the helium fusing phase. ",
"Rather, a star goes red giant at the beginning of t... | [
"There is so much wrong in your comment...",
"Potassium is one of those elements",
"It is not, at least not in any relevant amount. The fusion products are the products of multiple helium nuclei, so they all have an even number of protons, and typically as many neutrons as protons. Potassium has 19 protons and ... |
[
"Transmission via sexual contact"
] | [
false
] | Is there some sort of phenomenon similar to Blood/Brain barrier for the genitalia? In other words, if someone has a cold/flu, can there be transmission via seminal fluid? Also, if the ill person performed cunnilingus on the woman, would transmission be possible? | [
"It most definitely can be, though not necessarily what you're expecting.",
"Let me put it this way:",
"I had the joy of treating a chlamydia pneumonia once. Only one way to get that."
] | [
"So you've got this patient with multiple infections, pneumonia, compromised immune system, sick enough to be in the ICU. And the thought that disturbs you is that he gave somebody a blowjob?"
] | [
"We aim to deliver here at ",
"r/Askscience",
"!"
] |
[
"What is the biggest scientific project that we could create given an unlimited budget and all the unlimited labor force of the world?"
] | [
false
] | Examples: Space Elevator, launch loop, tower of babel, fusion reactor, reverse-engineering the human brain, etc. Unite the world's research infrastructure, manpower surplus, and greatest minds to create a huge project which requires international cooperation. Then do it. | [
"If we had unlimited budget, labor force, and thereby unlimited cooperation among states, we could quickly become a Type I civilization on the ",
"Kardashev scale",
". If we maintain that momentum, we could begin harvesting other planets and the asteroid belt in order to build a massive structure based on the "... | [
"Well I'll bite and add complete disregard of human ethics.",
"In that case there is an incredible amount of genetic engineering research that would suddenly be very accessible. Actually understanding the human genome by making hundreds of thousands of mutants with specific genes disabled or over exposed. Sure, l... | [
"I would say developing a system to cheaply, reliably, and safely mine the moon for Helium-3.",
"Something more down to earth could be to build large indoor greenhouse like structures further north in the vast stretches of the sub-arctic tundra, like the Yukon, NWT, Siberia.",
"We could also put more effort int... |
[
"Are there any medical effects of human cannibalism?"
] | [
false
] | Not that I'm considering it, but I've been looking for this answer for a while and have heard that it may give people brain diseases or heavily negative effects to health. What would happen if I were to eat a human? And if nothing, what could happen? | [
"The brain disease Kuru on Papua New Guinea is caused by a human prion obtained from eating the brain of a dead person. \nThe disease is widely spread among the tribe Fore who used to eat the brain of the dead tribe members.\nFor more info try Wikipedia: ",
"www.wikipedia.org/wiki/Kuru_(disease)",
" or ",
"ww... | [
"Yep, essentially. There was some discussion as to whether part of the issue was the cooking process as in the UK continuous feed systems (conveyor belts through a big oven) were acceptable whereas in other countries batch processes were used. Batch processes are inherently more reliable in getting all of the produ... | [
"Yep, essentially. There was some discussion as to whether part of the issue was the cooking process as in the UK continuous feed systems (conveyor belts through a big oven) were acceptable whereas in other countries batch processes were used. Batch processes are inherently more reliable in getting all of the produ... |
[
"What would happen if you detonated the largest nuke in the world at the bottom of Challenger Deep?"
] | [
false
] | If you detonated the at the bottom of what could we expect? Would it generate a tsunami? How big would the explosion be above the surface? Assuming the nuke is inside a container capable of withstanding the pressure of being at that depth. | [
"This calculation is almost perfect...",
"... except it ignores that the boiling point of fresh water at 111 MPa (1110 bars) is ",
"in the order of 300 degrees C",
". Seawater would be even higher. In fact, we know that saline water ",
"even at more moderate depths doesn't boil at 400 degrees C",
"."
] | [
"As FearTheCron said, 7 miles of water is a LOT of water to absorb the energy. Let's see how large a cylinder 7miles long needs to be to absorb all that energy without exceeding 99°C (remember that with increasing pressure at depth, water could reach a higher temperature without evaporating).",
"First, let's assu... | [
"Wow so the explosion would not cause any disturbance directly above it since its 7 miles below the surface? I would think that water would have to go somewhere. "
] |
[
"Say i wake up and I'm very dehydrated, or just did some manual labor for an hour in the hot sun without water, What is the most optimum way to rehydrate? A liter all at once? or 8 oz. every 5 minutes?"
] | [
false
] | Essentially i'm asking should i chug a whole lot of water when i get really dehydrated? or is it more efficient to go another route? | [
"The most optimum way is to run an IV. Chugging a lot of water will likely make you sick defeating the purpose.",
"Edit: Because I am being downvoted, ask any doctor the best cure for a hangover. IV fluids. Many doctors I've been told will give themselves IVs after a night of drinking. "
] | [
"Thanks, Yea i was thinking of something i could do. "
] | [
"I think it might be because the second part of the question was and either-or and the IV fluid wasn't an option. But I still tried to get your points back to zero. "
] |
[
"why do prion diseases only affect the brain and not other organs?"
] | [
false
] | null | [
"There are two aspects to this. First, prion diseases are caused (perhaps) by accumulation of misfolded protein fragments from the ‘prion protein’ found chiefly in the CNS. The masses or aggregates of this material are termed amyloid due to their tinctorial properties (that is, how they stain in microscopic prepara... | [
"This isn't really an answer, this is just moving the problem one step further. Why are those prion proteins nearly only found in the brain?"
] | [
"You’re right and wrong. “Prion” stands for “proteinaceous infectious particle” (and yes, Prusiner knew it should be “proin” but he rightly thought that sounded stupid) and there are examples of prion-type proteins in non-vertebrates, like yeast. ",
"But as well as a class of proteins, there is a specific, verte... |
[
"If hot water (~55°C, 328 K) contains only ~10% more thermal energy than room temperature water (~22°C, 295 K), why does it seem to help you clean, dissolve, cook, etc. so much more effectively than a simple ~10% improvement?"
] | [
false
] | [deleted] | [
"Both of your instincts are correct. The reactions that we care about are typically sensitive to temperatures changes near where life thrives, and reaction rates are exponential with changes in temperature. ",
"To focus on the cooking rate question, there's a minimum amount of energy that must be overcome in orde... | [
"Cooking for many biological molecules is a thresholded effect. The molecules will hold their normal state until you pass some specific temperature bound. Cooking protein is largely the process of heat denaturing the protein. This happens most efficiently at temperatures greater than 45°C and you would expect to se... | [
"That makes a lot of sense - thanks much for the excellent explanation. I ",
" learned a lot of that stuff years ago but it had gotten funny. The Arrhenius equation is totally satisfying since it not only includes an exponential term, but activation energies and a scaling factor. These variables could all be dial... |
[
"How come gemstones don't cold weld?"
] | [
false
] | [deleted] | [
"Metals are the only thing that can cold weld because with no oxide layer, the interface at the atomic level is immediately ready for bonding due to the nature of metallic bonds, basically. Gemstones have a lattice of strong intermolecular bonds which need considerable force to break and rearrange."
] | [
"It may be possible to ",
"wring",
" polished gemstones together if their surfaces are flat and clean enough. Full cold welding is unlikely because (1) gemstones ",
" essentially oxidized; that is, their surfaces have reconstructed and reacted with the atmosphere to attain stability; (2) the surface is coated... | [
"Thank you for this answer, I appreciated it."
] |
[
"Would a stove top steam powered generator be a cheaper more efficient way of producing electricity than getting it from the grid?"
] | [
false
] | Totally appreciate that there's a lot of variables in this question, so will probably be wiped by the mods. But I am curious to know whether you could create enough power for a typical house just using steam created by a domestic gas supply. | [
"Power plants use turbines which are about as efficient as you can get in converting to electricity."
] | [
"True, but power lines are surprisingly close to lossless. Total distribution losses are about 7% according to Wikipedia."
] | [
"Yeah but there are losses incurred over the vast area which it has to be distributed. "
] |
[
"Terpenes are isomers of benzene. Does heating and inhaling terpenes pose the same cancer risk as inhaling Benzene? Why or why not?"
] | [
false
] | null | [
"Terpenes are most definitely not isomers of benzene. As soon as you sober up, go read the wikipedia articles on isomers, benzene, and terpenes. I strongly recommend learning the definitions of the words in the questions you ask. Also, none of the chemicals you listed includes an aromatic ring.",
"Having said tha... | [
"I deleted the question, I guess I need to do more research on it. I wasn't exactly clear what an isomer was, and certainly not aware of the biological reaction tendencies of these chemicals as you mentioned."
] | [
"No problem. The curiosity you have is a great positive attribute and you seem to have a general scientific literacy. Using those two together will build your scientific knowledge and understanding. So while your question was technically moot, it was not a bad question, because it lead you to learn that when it com... |
[
"If an alpha particle is a helium nucleus, can it combine with electrons to form helium?"
] | [
false
] | null | [
"You got it boss. A helium nucleus + 2 electrons = helium atom. "
] | [
"That's where we get the bulk of our helium on earth actually. Radioactive isotopes in rock decay by alpha emission, so there's large amounts of helium locked up underground, although not large as it used to be as the helium deposits on earth are running out as they get mined for industrial reasons - helium is real... | [
"Does this regularly occur in nature? Is it a viable form of producing helium?"
] |
[
"Are the mRNA vaccines for Covid-19 thought to be effective against any other viruses with spike proteins, or exclusively SARS-CoV-2?"
] | [
false
] | null | [
"Not likely. What you’re talking about are known as off target effects where a targeted therapy towards one thing hits something else. Think of your vaccine and covid as puzzle pieces that fit together. When we design vaccines, it’s made so that only the two pieces we want fit together, otherwise it’s very difficul... | [
"Gotcha, makes sense. So when developing a vaccine it is important for it to be singular in effect, so you know both what it can do and what it can’t do. This limits the need to study situations outside of its focus and scope. Thank you!"
] | [
"Yep you’re spot, that and also that it’s just too risky to put anything in the body if you think it might bind to something other than what you want it to bind to."
] |
[
"What would happen if a magnetic shift were to occur on Earth?"
] | [
false
] | [deleted] | [
"This, but it would have an effect on migratory birds - as the poles switch they will be migrating to different climates they aren't conditioned for. "
] | [
"While birds may be able to detect magnetic fields for orientation, most studied birds migrate based on the stars and sun position. A study showed that a clump of stars near the north star are what the birds are entrained to use as a navigational marker.",
"For more information on migration and other once in a li... | [
"The poles would read different on a compass, that's about it."
] |
[
"Is the tolerance towards spicy food a function of nature and/or nurture?"
] | [
false
] | I'm of Indian descent (dot, not feathers) and I find it astounding when my Italian friend could not even handle a spoonful of cooking with regular masalas. He started sweating and flushing and I had to issue emergency orange juice and couple of spoons of oil to clear his system. How does one get "immunity" or tolerance... | [
"FYI - use milk instead of OJ for spicy food emergencies",
"http://en.wikipedia.org/wiki/Capsaicin#Food"
] | [
"Supertasters seem to have heightened reactions to bitter taste, but I have seen no evidence that they have a different reaction to capsaicin.",
"I actually do some research with capsaicin as an experimental pain model. It is thought that repeated exposure to capsaicin depletes Substance P in Group C nerve fiber... | [
"It's both. ",
"There are people who are known as \"",
"Supertasters",
"\" who have more sensitive taste buds than others, the wiki says it's 25% of the European population. Just based on random genetic variance, I'd imagine some people have strange sensitivities too (like people have random allergies.)",
... |
[
"Why do I still have to pee when my body is dehydrated, even if I've only had water to drink (no juice/soda/etc)?"
] | [
false
] | null | [
"Your pee not only contains water, but ions such as sodium and potassium, acids, and many other particles filtered by your kidney. Your kidney is the main organ involved with balancing all these ions in your body. If you are dehydrated then the osmolarity of your blood is increasing (the amount of ions per unit of ... | [
"urination doesn't just expel excess water, it also expels all the stuff that was filtered by your kidneys. You still need to get rid of this stuff even if you don't have much excess water to do it."
] | [
"This accounts for the darkening of urine during dehydration, because your body is minimizing the water loss making the urine more concentrated and dark",
"1.) How do B vitamins darken the shade of urine? ",
"2.)I've learned that it is better to drink your own urine than the saltwater of the ocean, which provok... |
[
"How strong is the gravity of a neutron star?"
] | [
false
] | Considering neutron stars are very small but can have the mass of several suns, how fast approximately would something fall towards them and how much energy would be required to leave their surface? | [
"Neutron stars have masses of about twice the sun and radii of around 10km. This gives you a gravitational acceleration of about ",
"2.5 * 10",
" m/s",
", or about ",
"10",
" g's",
".",
"On Earth, if you drop something from 1m, it will be moving ",
"4.4 m/s",
" when it hits the ground. On a neutro... | [
"If you dropped an asteroid on a neutron star from 30 AU, how fast would it be going when it hit?"
] | [
"The escape velocity for a \"canonical\" neutron star (M=1.4 times the mass of the Sun, R = 10 km) is almost ",
"2/3rds the speed of light",
". So just reversing it, roughly around that (slightly less) for a point mass (the asteroid) from 30 AU.",
"FYI, if anyone is interested, the relativistic escape velocit... |
[
"Does lightning produce x-rays?"
] | [
false
] | null | [
"Yes, it does.",
"X-ray emissions from thunderstorms have been known for a while already, but it's been a little mystery as to where they exactly came from. X-rays are highly energetic photons and for quite some time it was assumed that electrons in lightning discharges could not obtain sufficient energy to creat... | [
"Yes, some scientists captured lighting strikes using x-ray cameras. See pictures in this article:",
"http://news.nationalgeographic.com/news/2010/12/101223-lightning-x-rays-camera-science-technology/"
] | [
"Thank you for the detailed answer. It's more weird and interesting than I had expected."
] |
[
"What's the underlying cause of tectonic plate movement?"
] | [
false
] | [deleted] | [
"Something called ",
"slab pull",
" is the largest of the ",
"driving forces of plate tectonics",
". In essence, the higher density of a subducting slab, drags the rest of the plate with it. I believe it accounts for well over 3/4 of the forces involved. Mantle convection is probably not a major factor at a... | [
"I actually use this image in class, but it is deceiving. For more on driving forces see ",
"here",
" and ",
"here",
". ",
"Seismic tomography",
" reveals that movements in the mantle consist of large ",
"upwellings and downwellings",
" that appear to be independent of plate movement. In the image, ... | [
"I'm not sure how accurate this is, but ",
"this sort of image",
" made a lot of sense to me. Confection currents in the mantle, care to shed any light on that?"
] |
[
"Why is this year's influenza outbreak so much deadlier than previous years?"
] | [
false
] | null | [
"It ",
" deadlier because people have the historical awareness of tree squirrels. This is certainly a bad flu year, but it's about the same as several other fairly recent years. Look at the mortality charts in the ",
"CDC FluView",
" page. It's a good match for both the 2012/2013 and the 2014/2015 flu season... | [
"But in 2012/13 the match was pretty good and it was still a relatively bad flu year. In any case, the percentage of Americans who get the flu vaccine is pretty low, well under 50%. I haven't run the numbers, but it's hard to believe that herd immunity kicks in at that level, even when there's a relatively effectiv... | [
"But in 2012/13 the match was pretty good and it was still a relatively bad flu year. In any case, the percentage of Americans who get the flu vaccine is pretty low, well under 50%. I haven't run the numbers, but it's hard to believe that herd immunity kicks in at that level, even when there's a relatively effectiv... |
[
"Why is 7nm considered the limit of Moore's law?"
] | [
false
] | I understand that around 7nm silicon can no longer be used, but I am unsure why. I have seen that using graphite can lower the limit to 5nm, but again unsure why. | [
"Commercial integrated circuits today are made using projection methods. This can be grossly simplified as follows.",
"The wafer is coated with photoresist. A stencil of the circuit is projected onto the wafer; where the light hits the photoresist, it gets developed just like an old analog camera. This process is... | [
"Re-reading the original question again, you were really asking about the difference between silicon and other materials. This is not directly effected by lithography techniques. Answering requires laying out some core concepts though.",
"I mentioned in my previous reply that ICs are basically made from 3-dimensi... | [
"Silicon becomes too thin to predictably prevent gate leakage. Different materials are needed."
] |
[
"Imagine an android pattern-based lockscreen with a 6x6 grid, how many possible combinations/permutations are there in this scenario?"
] | [
false
] | This was a random thought I had today as my pattern lockscreen is a 6x6 grid instead of the usual 3x3. Due to the nature of how you could draw your patterns, my family and I, non-statistician laymen, were trying to figure this out. One answer was that the number of combinations/permutations would be less than 36! (fa... | [
"A 6x6 grid has 36 points. ",
"Calculating how many moves that gives you is going to take a lot more time, since it probably also depends on where you start, but it's going to be a lot less than 36!",
"EDIT: of course, for any string of points, you have 36 (or 32, if there's a minimum number of points needed) p... | [
"Uhhhhhhhh.... yeah.... I kinda missed that, didn't I. ",
"All sequences starting with 1 that end after 1 point are the same. ",
"So its actually 36 + 35x36 + 34x35x36 etc"
] | [
"If you have the geometric restriction, then I don't think there will be an expression that you could plug into your calculator to compute this quantity. However, with a computer it would be feasible to compute depending on the length of your password. This isn't as much statistics as it is combinatorics and graph ... |
[
"What makes a Zebra, A Zebra, and not just a differently colored horse? How far apart are they genetically?"
] | [
false
] | null | [
"They have different numbers of chromosomes. A donkey has 62 chromosomes, a horse has 64 and the zebra has 32 (or 46 depending on species). Even within zebras there are different species, so keep this in mind. Viable hybrids are possible (think mules or hinnies for horseXdonkey crosses). These hybrids are called ze... | [
"There are 3 different species of zebra; Plains, Grévy's and Mountain zebras. Zebra is a category like bear (Brown bear, black bear, polar bear) not a species."
] | [
"Not to produce fertile offspring. We just call them zebras because they look so similar. Zebra isn't the official species."
] |
[
"If i had a cube that occupied a volume of 1in x 1in x in, is there a known maximum surface area that it could attain, or is it theoretically unlimited?"
] | [
false
] | null | [
"One cubic inch would be the volume. But what you're now referring to is a Menger Sponge - a fractal with infinite surface area.",
"http://en.wikipedia.org/wiki/Menger_sponge"
] | [
"Its surface area is six square inches."
] | [
"Are you talking about etching/moulding the surface with something like a fractal pattern to extend the surface area?",
"Depending on what the cube is made of, the limit would be set by the size of molecules/atoms or exotic matter (e.g. the cube is made of neutrons as in a neutron star).",
"So - the surface are... |
[
"Do people that speak different languages get different located wrinkles?"
] | [
false
] | [deleted] | [
"Although possible, wrinkles dont nessecarily form due to repeated flexing of skin at the same point. Instead, wrinkles are normally formed either habitually due to muscle developments, or more often due to specific weakening of the collagen present in the skin at that point."
] | [
"But wouldn't different languages form different muscle developments?"
] | [
"Maybe some small miniscule changes at most, it's quite hard to say. Given the fact that even though different cultures use different muscles in the face for their different languages, they use the same muscles for many more things, such as emotions and eating"
] |
[
"Orientation of an object in orbit"
] | [
false
] | Hi there, I was just watching some sci-fi, and there was a ship in orbit of a planet. And they showed it as orbiting always with one side to the planet. What my understanding of physics tells me is, that object in orbit doesn't change orientation, that is, there's no side that is permanently turned to the planet. How i... | [
"It's to do with tidal forces when it comes to things like the moon, I was just giving an example that even some natural phenomena can do it.",
"Artificially, it's extremely easy to do. Just thrust gently one way or the other to give the ship a net angular momentum about its center of gravity such that it makes o... | [
"It could slowly rotate at the same rate that it orbits, the moon does this."
] | [
"Well, by tidal forces, I mean a very specific phenomenon. Due to the fact that gravity is weaker further away, you'll find that large objects in the midst of a gravitational field will feel a noticeably stronger force on the side closest to the source, this causes the object to become slightly elongated. If the ob... |
[
"Have we been imaging the Crab Nebula (or other extrasolar objects) for long enough that we can see changes between the frames?"
] | [
false
] | [deleted] | [
"I think one of the more impressive animations is of the stars orbiting the supermassive black hole at the center of the Milky Way:",
"Animation of actual photos taken over 16 years",
"Computer animation",
"This one is good too:",
"Crab nebula pulsar - 6 months"
] | [
"Yes"
] | [
"Yes! But it seems we've really only been able to collect photos taken with similar-enough photographic technology and register them (properly position sequential frames on top of each other) within the last 25 years or so. Search youtube for \"timelapse nebula\" or \"timelapse supernova\" to find things like thi... |
[
"Why can you cut some objects, such as a ball of clay, in half and then combine\\reshape the halves so that no crease or cut exists, but you wouldn't be able to do this with other objects, such as a slice of bread? What property determines this?"
] | [
false
] | null | [
"I think clay is technically an emulsion. Small solid particles kept in stiff suspension by interstitial water molecules with a polar attraction to the particles. If I recall, most clays are comprised of metallic silicates which would be hydrophillic so water is quite happy to wet them and hold them together by sur... | [
"You ",
" cut molecules with a knife. Or at least crush them apart, which is what happens on such a scale."
] | [
"This is the answer. Dry clay (with no water to hold it together) does not have this property. "
] |
[
"How do patients that have recovered from Covid, test positive again?"
] | [
false
] | [deleted] | [
"The media has made a lot of fuss about this, but few scientists are convinced that those repeat-positives are truly reinfections. Rather, they’re probably false negative tests taken between two true positives. We know that false negatives are fairly common with the available tests, so this is by far the simplest e... | [
"If reinfection ",
" something that happens, maybe a couple months. If it’s not, then several months to years, til there’s some idea of how long immunity lasts."
] | [
"So going by this, the re-infection is still technically the original infection someone had and it just stays in their body longer as it slowly deteriorates with time but there's not enough to be detectable in a test? So it's not technically a re-infection, it's the same exact one they got the original viral dose? ... |
[
"Do other vertebrated animals have puberty like we have?"
] | [
false
] | I know that some invertebrates go through metamorphosis, but what about other mammals, reptiles and birds? Do they also go through major body, hormonal and brain changes like we do during that period? | [
"Yes, absolutely. There are 3 key things to look out for.",
"First is physical changes. In most animals, once they reach sexual maturity they stop growing larger. They often develop secondary sexual characteristics, particularly males. These could be weapons like antlers, bright colouration like birds' plumage or... | [
"During puberty female rabbits develop a dewlap- a section of fat under their neck. Its meant to indicate sexual maturity/fertility. During that time, they also get way more territorial (grunting, pouncing, etc. on whoever gets in their space)"
] | [
"I raise ducks and geese. ",
"Absolutely they experience a \"puberty\". ",
"Temperament changes,",
"\nThey go though vocal changes that go from a pip/squeak to a kinda \"voice break\" call similar to human males, to a full on honk/quack/hiss.",
"\nThey get much larger - in the case of Muscovies, a dimorph... |
[
"Comet assays: What do you analyse, statistically?"
] | [
false
] | [deleted] | [
"Both measurements -- intensity and areas of the head and tail -- are useful, no?",
"The intensity of the tail in comparison to the total DNA would tell you how much DNA is damaged, and the area of the tail in comparison to the total comet would tell you a bit about what size fragments are produced. "
] | [
"Intensity and moment are essentially the same thing. I guess the only difference would be whether you're comparing the tail to the head of the same comet or if you want to compare two different comet tails. ",
"Please take what I'm saying with a grain of salt, since I've only read about comet assays, never actua... | [
"What about in comparison to the tail moment though?"
] |
[
"If all matter is made of same stuff (atoms), the only difference being the number of electrons/protons/neutrons, why is there such an amazing variety of elements, substances, materials and what not possible?"
] | [
false
] | In other words, why are materials/elements so vastly different if they are all pretty much the same when broken down into their smallest particles? | [
"The electrons around an atom are arranged in different configurations when you look at different atoms. These differences in configurations account for most of the effects you see in molecules: different bond types, different spacial arrangements, different energy barriers... And then there're thermal effects too ... | [
"There are about 100 unique elements, so there are about 100 kinds of single atom. But when you have two atoms, there are 10,000 possibilities. Three atoms, there are a million. When you start getting into many-atom compounds, the number of possibilities increases exponentially."
] | [
"I'll give a shot here at a couple of your questions.",
"First off, you need to think more on a level of properties instead of physical balls floating around. The fundamental tenet of basic chemistry is the ",
"Electrostatic Force or Coulomb's Law",
". This basically states that a proton will be attracted to ... |
[
"Do amputees have the same amount of blood as a standard four limbed human? Moreover, would the effect of illicit substances vary?"
] | [
false
] | null | [
"The amount of blood a person has is based on his or her lean body mass and sex. Greater for males and lesser for females. So when a person loses a limb he or she also loses a portion of his or her lean body mass.",
"Overall the loss is negligble, but yes an amputee has less blood than a person with all of his or... | [
"And using alcohol as an example: Since there is less blood in your system, the same amount of alcohol will create a higher blood-alcohol level because the concentration is higher. I.e. alcohol/blood > alcohol/blood-limb loss."
] | [
"Correct. This is why larger people can typically drink more alcohol and have the same BAC than a smaller person that drank less."
] |
[
"How does intelligence change with age?"
] | [
false
] | Feel free to answer this question from any academic angle you feel is appropriate. Also, please link or cite any research articles if you are referencing them. | [
"An accepted academic philosophy states that as we age, we gain a form of \"crystalized intelligence\" which is formed through the brain's natural assimilation of lived experiences. But although we gain this \"intelligence\" other variants such as kinesthetic and operational intelligences greatly diminish. This is ... | [
"CHC theory is the top theory of intelligence at the moment. Piaget is only useful during early development up until adolescence. Piaget is typically used for children with major neurological/neurodevelopmental challenges, such as those with a nonverbal form of autism. ",
"To answer OP's question, cognitive abili... | [
"CHC theory is the top theory of intelligence at the moment. Piaget is only useful during early development up until adolescence. Piaget is typically used for children with major neurological/neurodevelopmental challenges, such as those with a nonverbal form of autism. ",
"To answer OP's question, cognitive abili... |
[
"What is the chemical reason (or reason at the atomic level) for ceramics to generally be strong in compression, and weak in tension? What is so special about the covalent/ionic bonding?"
] | [
false
] | I understand that brittle materials have a low , but I'm not sure whether the two are directly related (or how they're directly related, if I'm on the right track to the answer). But really, I'm interested at the chemical reason at the atomic level, if there is one. | [
"Fracture toughness and brittleness are indeed closely related; brittle materials have, generally speaking, low toughness. The reason for the qualification is that \"brittle\" vs. \"ductile\" describes the ",
" of a material, while toughness is a ",
". A material with a high value of toughness (measured in one ... | [
"I beg to differ. The brittleness of ceramics can be explained perfectly well on the atomic level. What we consider \"ceramics\" are the solids which have mainly ionic or covalent bonds. As these bonds have certain \"directions\" in the space (due to atomic orbitals symmetry), they behave as \"stiff sticks\" and th... | [
"It's really more 'mechanical' than 'chemical' in origin. It's indeed related the facts that you mention, that they're brittle and fracture easily. A bulk/'macroscopic' quantity of ceramic isn't likely to be a perfect single crystal. Rather it's a bit of a hodge-podge of microscopic crystal grains that aren't so st... |
[
"Is breakfast really the most important meal of the day? Why/Why not? How long after waking is the ideal \"breakfast time\"?"
] | [
false
] | null | [
"Probably yes (at least most important to be aware of, since it tends to be skipped most often), although most studies only research breakfast as part of a continous, healthy diet where you eat at least three times a day. This means that lunch skipping may be equally bad.",
"This study",
" summarized the result... | [
"Some nutritionists suggest that large breakfasts decrease appetite through the rest of the day. However weight loss studies show that if you skip breakfast and still end the day with a calorie deficit, it is just as effective as a tapered meal size from breakfast to dinner. So basically no, it is not the more impo... | [
"I am actual most interested in the original poster's last question, which was how long after waking is the ideal \"breakfast time\"? I read the entire thread and didn't read any responses to that, and I would like to know if there really is an ideal time to have breakfast."
] |
[
"How does OLED Multi View glasses work?"
] | [
false
] | Talking about . How do they get the glasses to only show view? | [
"They use polarisation. This is a director quantity that light has; there is some line you can draw representing the direction of polarisation. The following explanation is simplified, but hopefully gives the general idea.",
"If you put a grid of thin lines in front of the light (with appropriate sizes etc.), the... | [
"Thanks!"
] | [
"With this tech, the most common way is that it shows one video frame for person A, person A's glasses lets it through, B's blocks it, it then shows one for B and A's blocks it. This happen 60 times per second, usually, giving a total of 120 frames per second. Both A's and B's eyes only see their own video fluently... |
[
"If a single Pangea-like supercontinent were located within the Antarctic circle with no other continents anywhere on the globe, would our planet have an Arctic ice cap?"
] | [
false
] | Assume today's climate, and the shallowest depth at any point in the Arctic circle being no less than 2500 meters. If the answer to the question is yes, what keeps this hypothetical arctic cap from just floating away to the equator and melting? | [
"There's a rather contentious hypothesis called \"",
"snowball earth",
"\" that is speculated to have happened at a point in Earth's history when ",
"just such a super continent",
" was, while not centered on the south pole, pretty much entirely within the southern hemisphere. The idea goes that this causes... | [
"I imagine, for the north polar ice, what ice does break off and float south is replaced by the formation of new ice at the pole.",
"I get that your a guessing on this, but it seems to me that the rate at which new ice gets made would not be faster than the rate at which ice floats away? I'm not imagining broken... | [
"Well that would depend on ocean currents and whatnot right? I mean ice doesn't just migrate to the equator, it's got to get pushed there. So if ice forms in the north ocean because it's sufficiently cold and able to form, it may slosh around a bit locally, at least until the whole local region is a big mass of ice... |
[
"is it a rumor or a proven fact that stress causes hair loss?"
] | [
false
] | i'm 19 (male) and im pretty sure what i have noticed classifies as hair loss, if i shower i end up with hair everywhere and if i comb my hair, the comb gets filled with hair in 30 seconds. could this be caused by stress or should i be worried about my health? | [
"Along with the types of hair loss already mentioned, there is a temporary type called telogen effluvium that is often caused by stress. This just means that more of your hair than usual goes dormant at the same time, so three months later the hairs fall out. But the fact that they're falling out also means that ne... | [
"Even if you are under stress, if you are newly losing hair at that rate get to a doctor. There are lots and lots of diseases, syndromes and endocrine issues that can cause hair loss and you need to make sure it's none of those. Hopefully it will just be stress."
] | [
"Damn. I hope she's okay now. That sounds pretty extreme as far as stress goes"
] |
[
"How do you respond to people when they say \"Time isn't real\"?"
] | [
false
] | I'm hoping this can be a scientifically answered question and not a philosophical question. I have a bunch of friends who feel this way and the only thing i can ever think to say is "It's in important equations and stuff". Is there a way to answer that isnt too complicated? | [
"\"Good. Then you won't mind that the rent is going to be late.\"",
"But seriously, time is every bit as real as space. The whole business of special relativity is pointing out that they are (almost) the ",
" thing."
] | [
"You can ask them exactly what they mean by that statement. If they mean that all matter never changes, waves never propagate, and energy never changes form, then they are wrong.",
"If they mean that an event taking \"the duration of 9,192,631,770 periods of the radiation corresponding to the transition between t... | [
"'moving right along....'"
] |
[
"Do two objects of different masses exert the same amount of forcer on EACH OTHER?"
] | [
false
] | Lets say object A is 10 is units of Mass, while object B is 20 units of Mass. Will both objects exert the same amount (strength) of gravitational force on each other? Assume they are 5 units of distance away from each other. I'm having a hard time wrapping my head around this concept. I know the force of gravity betwe... | [
"They exert the same force on each other, but because they have different masses, they experience different ",
".",
"Both feel a force of GMm/r",
", where ",
" is the distance between them, ",
" and ",
" are their masses, and G is the universal gravitational constant. But the acceleration of each object... | [
"Yes! When you are standing on the earth, the amount of pressure you are applying to the ground is the same as the pressure earth is applying to your feet. You are attracted to earth with the same force that the earth is attracted to you."
] | [
"One way to conceive it is by visualizing gravity as a curvature of space-time:",
"https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2015/09/spacetime_curvature/15576375-1-eng-GB/Spacetime_curvature_pillars.jpg",
""
] |
[
"Did Natural Disasters (Hurricanes, tsunamis) always happen from the beginning of time?"
] | [
false
] | null | [
"Well, \"beginning of time\" isn't a very useful measure, because the Earth is much younger than the universe. There is also the issue that, for example, hurricanes require an atmosphere, and the Earth did not always have an atmosphere. However, the Earth has had an atmosphere for the vast majority of it's 4.5 bill... | [
"There are of course \"hurricanes\" on other planets, which have a very different atmosphere to earth. "
] | [
"A noteworthy example being the red spot on Jupiter (although this is technically an anti-cyclonic storm, meaning its wind currents are in the opposite direction as would be expected due to the Coriolis force, but for the sake of talking about large storms in an atmosphere on another planet, it's the most famous)."... |
[
"why did earth's tectonic plates split? and if it didn't would we get volcanoes or earthquakes at all? and what would the earth still look like?"
] | [
false
] | null | [
"I love this question. My job, in part, is to answer it...",
"The Earth, like all rocky planets, formed from a process called accretion. Here, the dust of the presolar nebula condensed to make rocks, which impacted each other. The largest meteors would attract the smaller ones, gaining material, and growing in ti... | [
"Thank you for that detailed explanation, it's scary to think that a planet the about the size of Mars, collided with earth is what basically started life, but if that where to happen now we would be wiped. "
] | [
"Sorry if it was long, but I tend to ramble and people are critically misinformed about the Earth! ",
"It probably wouldn't happen now. Accretion has slowed to a standstill. All those craters you see on the moon? They're mostly ancient. A long time ago, Jupiter and Saturn switched orbits, flinging meteors and com... |
[
"Why are some of our organs so oddly shaped?"
] | [
false
] | The eye seems pretty reasonably shaped for its purpose. The ear is weird, but it makes at least sense after you consider the need for sound waves to enter it a certain way. But why is the stomach so oddly shaped? Why are kidneys kidney-shaped? It seems like there could be a more efficient configuration for the many org... | [
"I'm not sure about the stomach, but the ",
"structure of kidney",
" makes pretty good sense as an filtration/exchange interface between blood and urine.",
"Also, note that evolution does not have foresight on design, it can only build on top of what's already present."
] | [
"Evolution doesn't necessarily lead to the most efficient solution. ",
"One of the nerves for our throat",
" travels from the brain and around the chest area before connecting to the mouth. That's a similarly inefficient situation, and the reason they both came to be is essentially that it was the first solutio... | [
"Absolutely right about the fact that evolution doesn't care about the final design, just on short term advantages/disadvantages.",
"That being said I can't think of any organ whose shape actively hinders its function. Sure there are things that could possibly be designed better, but as things are, they are prett... |
[
"Two questions here regarding lightning."
] | [
false
] | I'm in Decatur, Illinois and it's 12:48 AM. There has been lightning nonstop for about 30 minutes now. it's yellow and forky. My questions: What causes nonstop lightning like this? There is a thunderstorm nearby but in my 15 years of living here I've yet to see something like this. My 2nd: Why is some lightning yellow ... | [
"I can only speculate",
"definitely",
"wat",
"And the wavelength of a star's light is not being shifted when it twinkles. Did you just mean that atmospheric conditions can influence light? That's definitely the case, but I don't think there's any wavelength shifting going on."
] | [
"My bad. Variation in color isn't from shifted wavelengths, but from anomalous refraction from shifting air densities."
] | [
"It's a good question, but as far as I've been able to find out, the understanding of lightning is still very incomplete. It seems to be proven that the charges are built up only when ice forms in the cloud. There was some work last year (sorry, can't find a source) which established that when ice particles collide... |
[
"Why does our immune system need one or two injections to learn to fight a new threat and many injections to unlearn to fight a perceived threat (e.g. dust mite)? Thanks"
] | [
false
] | null | [
"The goal of allergy shots is to slowly make your immune system switch from one type of immune response to another. In order to do that, they have to start with a super-low dose of the allergy trigger so that it flies under the radar of the allergy responders and instead gets the attention of a different type of im... | [
"Essentially yes. There are several phases that go into that transition and we don’t understand exactly how all of them work, but basically the low dose exposure triggers immune reactions that stabilize your allergy responders, turn down the volume on the allergic response, and hopefully eventually train the immune... | [
"So you still get an immune response, just not one that you notice?"
] |
[
"How do astronauts protect themselves from high energy cosmic radiation in space?"
] | [
false
] | null | [
"Astronauts in the ISS receive about 1/4 of the radiation dose that they would get in deep space. ",
"MSL during its transit to Mars measured about 1.8 mSv/day",
".",
"http://upload.wikimedia.org/wikipedia/commons/e/ef/PIA17601-Comparisons-RadiationExposure-MarsTrip-20131209.png",
"Most of the other comment... | [
"/u/katinla",
"http://www.reddit.com/r/askscience/comments/34iasc/how_do_astronauts_protect_themselves_from_high/cqv6vrj",
"In orbits close to the earth, the earth's magnetosphere offers most of the protection.",
"Beyond that, when levels get high, maybe caused by a burst of radiation from the sun, astronauts... | [
"https://www.hq.nasa.gov/alsj/tnD7080RadProtect.pdf",
"Short version: they weren't out there long enough to get harmful doses of radiation and there were \"...no major solar-particle events...\" during the missions.",
"This is one of the concerns to a moon base though, and I believe one idea to get around the i... |
[
"Why do we need an updated vaccine for the flu every year, but not for other preventable diseases like measles, rubella, and Hep B?"
] | [
false
] | [deleted] | [
"You are right that the flu virus is very good at mutating. What makes flu interesting is that it has two main ways of mutation: genetic drift and genetic shift. Antigen drift is \"normal\" mutation, where mistakes are made in the copying of the viral RNA, while antigen shift is when a human/animal is infected with... | [
"Influenza and Measles are both ",
"group V RNA viruses",
" they replicate using the same basic system and should have the same rates of mutation and the same vaccination narrative. ",
"So what's the difference? The answer is ",
"'Antigenic drift'",
" a process which occurs more frequently in influenza v... | [
"This is a hard question. I don't think we really know the full answer just yet. However, I can answer part of the question, specifically, why variant flu viruses that are resistant to last year's vaccine emerge each year. I do not know why other viruses are not able to do so, although I can speculate (the best par... |
[
"Would we know if exosolar planets were like Venus or Earth?"
] | [
false
] | Venus and Earth are roughly the same sizes. However, the living conditions contrast greatly. So would it be possible that any planets we find outside our solar system have the same kind of thing? | [
"I don't think we currently have the technology to do that but it may be possible in the near future for transiting planets. We can measure the atmospheric composition of astrophysical objects pretty well by studying their absorption spectrum. If the atmosphere has a significant green house gases then temperature r... | [
"Naturally it would depend largely on the distance to the planet. However, spectroscopists will tell you that when the new European 42m telescope is build they will be able to analyze the atmosphere of exoplanets. I think this might be our best chance of learning details about exoplanets (at least for the next few ... | [
"I remember seeing my Astr prof show me a graph of imaging technology growth and we're only a few years away from such technology."
] |
[
"Is Nuclear Transportation possible?"
] | [
false
] | More specifically, in automobiles? Whether it is or is not possible, what exactly would be the hypothesis behind it all (As in, what and how would that even begin to work)? | [
"Cars based on conventional nuclear technology wouldn't really be feasible. Nuclear-powered trains have been researched (do a search for \"Nuclear Locomotive\" if you are interested), but these are still not very feasible. A ",
"nuclear-powered bomber",
" was also pursued for a bit, but was made obsolete by c... | [
"It's possible in large ships and common in ",
"submarines and battleships for instance",
".",
"I'm certain it would be technically feasible to scale it down, but then there are a lot of safety issues that I don't know much about."
] | [
"RTG's can only put out a couple hundred watts... not nearly enough for a car. You need a hundred horsepower or so for that."
] |
[
"What is the state of a particle that has collapsed its wavefunction to one observer, but not another?"
] | [
false
] | Possibly, I may be thinking of a problem already addressed by quantum entanglement, but my idea was more me thinking about how an instantaneous collapse of a particle's wavefunction works with special relativity. I'm aware that the information that the wavefunction has collapsed cannot reach a distant observer faster t... | [
"What you're asking is a good question, but there's no consensus scientific answer. (It's part of the measurement problem. ",
"https://en.wikipedia.org/wiki/Measurement_problem",
" ) The answer is that people are still working on it. This problem is sometimes called Wigner's friend or Schroedinger's cat. ( ... | [
"As Rufus mentioned, you can't send communications faster than the speed of light so ftl wavefunction collapse still works with SR. \nAll the other forces as you mention, are just that \"forces\", which is the communication between particles, so speed limits apply here."
] | [
"But why is that special in that it can when every other force etc.. operates at speed of light"
] |
[
"Do stars make noises? Would we be able to hear the noises or sounds they emit?"
] | [
false
] | null | [
"Stars emit a ",
" of plasma; the sun's solar wind and its interaction with the earth's magnetosphre cause the aurora borealis and aurora australis. This thins out substantially with distance. The ",
"heliopause",
" of a star is where the stellar wind interacts with the interstellar medium. ",
"The oscillat... | [
"There is a very low-density medium of gas in space. Not air, not anything like air, but not a perfect vacuum. In the local planetary neighborhood this is the stellar wind. Conventional ears cannot hear it. But if sound is thought of as any vibrational mode in a medium, the stellar wind can have sound.",
"A star ... | [
"A star is just an ongoing explosion. If there were to be air in space the sound would be deafening. But since there's no air in space, there's nothing to carry the soundwaves. Thus we can't hear it."
] |
[
"How do we know the purpose of small statues and figures?"
] | [
false
] | When small statues and figures are discovers from prehistoric times we’re always told they may have been used in rituals or to ward off evil spirits or some such revered purpose. How do we know they’re not dolls or toys of some sort that the adults traded for a nice price of meat to keep the kids quiet? | [
"This is more of a question for historians than scientists, but to answer: A lot of the time they ARE identified as dolls and toys, there are some lovely Roman examples of dolls with articulated joints. If you google 'Bronze Age baby feeding bottle' you will see some very cute animal-shaped vessels for feeding babi... | [
"I saw a great cartoon where \"archaeologists of the future\" were looking at an Ikea standard lamp in a long-abandoned room. They said it clearly had a ritualistic or religious purpose, as one was found in nearly every house."
] | [
"Archaeology student here, it depends on the figurine/location/date. With later periods we can deduct ritualistic purposes as they are found en masse as offerings at temples for example. Figurines also served as toys, sometimes found in settlements but more so in children graves they are prominent. Now with prehist... |
[
"Matter / anti-matter annihilation"
] | [
false
] | When an electron and positron collide, they annihilate each other and the end result is pure energy (or also heavy particles at high speeds). Why is this energy not "anti-energy"? In other words, if the energy could coalesce, why does it all turn into regular matter and not anti-matter? | [
"'pure energy' doesn't really mean anything. Energy will have to take a form of some sort. ",
"High energy photons can and do decay into matter and antimatter (they turn into both, not just matter).",
"there is also no such thing as anti-energy. energy is just a number we assign to different things that has ... | [
"The end result is not \"pure energy\". The end result is photons. A photon is its own anti-particle. Photons, likewise, can collide, producing matter and anti-matter in equal proportions."
] | [
"How can photons collide? "
] |
[
"Is this how evaporation actually works?"
] | [
false
] | Tonight as I was driving my kids around I was thinking about the water on the windshield (from an earlier rain) evaporating. It was 39F out and I started wondering if my hand-wavy self-explanation of evaporation was correct I always pictured it as "micro-boiling", where air molecules on the far right of the boltzmann ... | [
"I think its a combination of both. Anything that gives a water molecule a sufficient amount of energy to overcome the intermolecular forces keeping it liquid will cause evaporation. Technically the water is exerting a vapor pressure on the air, which usually balances it with its own air pressure, and when the va... | [
"Also to add, water molecules that are not surrounded by other water molecules (the ones at the surface of a droplet) would have less net cohesion, and would evaporate more readily. The sheer force of the wind causes water to separate into smaller and smaller droplets, therefore creating more and more of these unco... | [
"You know I never really understood vapor pressure. ",
"I have these vague notions of its relation to molecules entering and exiting a liquid state, which is a function at the macro-level of the thermodynamic properties of the fluids... isn't it an effective pressure related to the chemical potential? ",
"I ... |
[
"In social settings, I stutter because I get anxious, and get anxious because I think I'm going to stutter. Why?"
] | [
false
] | [deleted] | [
"This could be caused by the anxiety triggering yourself to start physically giving commands to your mouth to say. I know that failure under pressure (what I would call \"choking under pressure) is very often caused by you physically trying to do the actions yourself, instead of letting your body naturally doing i... | [
"Not really, I'm curious as to WHY it happens, as in whats the science, rather than \"can you fix me?\""
] | [
"I've read something similar, it kinda made sense, but I'm wondering if there's a more scientific explanation "
] |
[
"How fast does gravity work?"
] | [
false
] | I was thinking about how, if you plucked the sun from our solar system, we wouldn't know about it for around 8 minutes or so. Then, the world would be plunged into darkness and we'd all die or something. I was wondering if gravity would act on the same timeline. Would the Earth continue to revolve around where the sun ... | [
"The speed of light. I answered a question like this before. ",
"Here",
" it is.",
"EDIT: For the lazy here is my answer. You should check out the link as well though because there are some other good answers there too. \"Gravity is one of the four fundamental forces of nature. Each of these forces has someth... | [
"The sun can't just vanish. Seems like stupid nitpicking, but it's actually crucial. General relativity is what gives us the answer to these types of questions, and if you put in this particular scenario with a vanishing sun, then you get no answer. Not an unphysical or nonsensical one, just no answer, period. The ... | [
"Thought experiments like the OP's question were key to Einstein and many others solving the mysteries of the universe. You can't really go the speed of light and pursue a beam of light but his 16 year old mind used it to figure out many things-",
"\"...a paradox upon which I had already hit at the age of sixtee... |
[
"What would happen if your body didn't try to fight infections?"
] | [
false
] | null | [
"This is actually a little bit difficult to answer because, as you say, the immune system is such a big part of the equation (see septicemia). If we were to completely remove the immune system from the equation, the short answer is you would literally just be overwhelmed. And quickly. The precise reason would be ha... | [
"There has been at least one case of this. Check out ",
"David Vetter",
", aka bubble boy."
] | [
"That sounds... unpleasant, to say the least."
] |
[
"Electronconfiguration of Lanthanoids"
] | [
false
] | My Question is basicly why do we "put" 1 electron into the d orbit (d1) befor we "put" electrons into the f orbit (witch has a lower "energielevel" !?). ( I`ll put here some thoughts i had in the last hour about that (its probablly total bullshit :P ) My gess is that it just "happens to be" a stable state for 1 electro... | [
"http://en.wikipedia.org/wiki/Electron_configuration#Other_exceptions_to_Madelung.27s_rule",
"The short answer is, \"things get complicated when there are a lot of electrons.\" When you have to start taking into account things like Special Relativity, things start to go funny in a way that's hard to explain with... | [
"As the page mentions, these exceptions can be predicted and explained by theory. So we do know the why part. It's getting really close to the edge of my field to explain it, but you would want to look at the fields of computational chemistry, ab initio quantum chemsitry, and electronic structure calculations to ... | [
"thanks, now i have at least a wikipedia page :P ",
"edit: ok, i looked though the page and i kinda get it but one thing: \ndo we know why this happens or do we just know that it does happen?!"
] |
[
"What is the penetrative power of an atom in a particle accelerator?"
] | [
false
] | [deleted] | [
"There's a man named Anatoli Bugorski who was struck in the head while inside the U-70 synchrotron (Soviet accelerator) in 1978. Part of his face is paralyzed now",
"If you want to read more"
] | [
"It depends on the kind of particle and its energy. Fast neutrons will go through basically anything, while heavy charged particles will not make it very far in dense matter."
] | [
"What kind of damage would that cause to a human ?"
] |
[
"Do any animals' legs have a markedly longer femur than tibia/fibula? If yes, why?"
] | [
false
] | null | [
"Looking into this a bit out of curiosity I found ",
"this paper by Demarco et al. 2018",
", which includes a decent table of limb proportions for various vertebrate groups. See the Y-axis of ",
"figure 12",
" for a graphical depiction. The smallest tibia:femur ratio in their list belongs to the plesiosau... | [
"Thank you. That's incredibly helpful. ",
"If that exaggerated femur developed in a land animal (either in a vertebrate or cartoonishly large invertebrate), would it have to be because the utility of a long limb was more important than the knee joint? ",
"Can you imagine a scenario where that might happen? Is t... | [
"Well, it's not really that the femur is exaggerated in this case, just that the tibia is greatly reduced. I can't really think of any land animals that would have anything close to that ratio. Though the reverse case of a much longer tibia than femur does exist within various jumping animals, like kangaroos for ... |
[
"Force exerted by the dynamic Casimir effect."
] | [
false
] | The talk of the possibility of a "space drive" based on the dynamic Casimir effect really intrigues me. If I'm understanding correctly, it basically violates Newton's 3rd law. I'm assuming the "moving mirror's" movement is sinusoidal. If you have some variables, such as the surface area of each plate, the average dista... | [
"The dynamical Casimir effect will ",
" lead to a net force, if you do the calculations correctly. The only person who appears to have claimed such a thing is an Egyptian teenager (who, to my knowledge, has not published any actual papers on the topic)."
] | [
"I see. I can't say I'm surprised, but I also can't say I'm not disappointed. Why did this receive so much coverage if it's just a bunch of nonsense? Also, what then is the difference between the static and the dynamic Casimir effect?"
] | [
"Well, it ",
" get much coverage from the kind of media outlets that actually get an expert opinion, rather than uncritically report claims.",
"The difference between the effects is just whether the objects are moving or not. Which shouldn't really be surprizing, as you always have such a difference with em for... |
[
"Oxygen is injected to purify molten pig iron. Why does it react with all the impurities, but not form rust (aka oxidize) with all the free iron atoms?"
] | [
false
] | The process I am referencing is described well in the link. | [
"Some iron ",
" oxidized to form iron(II) oxide in the slag and fume. Table III in the link provided by the OP mentions that 3.2 % of the charge is lost to slag and fume formation."
] | [
"Iron oxide will be destroyed at temperatures that high. The oxygen would be free until it encountered silicon or other elements with high melting point oxides.",
"When you weld (say) mild steel, you are relying on the fact that the surface coating of oxide melts at a lower temprature than the bulk material.",
... | [
"So you can't get iron from rust in a blast furnace ?"
] |
[
"Why does body hair stop exactly where clothes start?"
] | [
false
] | For example, look at your upper arm. Hair starts right about where a t-shirt sleeve would stop. Is this a genetic thing, showing that humans have more or less adapted to clothing, or is it merely that constant rubbing discourages hair growth? Partially inspired by kspr's question here: | [
"maybe clothes are made to stop where the hair starts."
] | [
"Short answer: it doesn't. It may for you, but that's nothing but a coincidence; body hair distribution is highly variable. I don't have any arm hair until around my elbow, my boyfriend doesn't have any at all, and lots of people have hair down nearly all of their arm."
] | [
"My shoulders, toes, and armpits join the party."
] |
[
"So I saw the submission on AskReddit about people with high iq. Why do people with higher iqs have concentration and motivation problems?"
] | [
false
] | null | [
"Do they? What evidence/source do you have for this statement?"
] | [
"The problem with your question is that a high IQ doesn't describe all the variables involved with concentration and motivation. Many people with high intelligence have hyperfocus and problems with obsession, too. ",
"So, with all that aside, I think you're describing otherwise neurotypical individuals who are bo... | [
"This. I've gone thru phases (130 IQ not massive but up there) where when I'm not challenged I'm unfocused on anything, my brain wanders uncontrollably (if anyone diagnosed me with ADHD I'd smash them in the face), and procrastination soars. However, if I KNOW something is important, is the least bit challenging, o... |
[
"Do optics (specifically colors) behave differently when looking at nano-sized materials?"
] | [
false
] | This question popped into my head while I saw some pictures during my solid state electronics class. Every time we're shown a picture of things the size below ~30nm, they are always black and white. Are pictures black and white because we don't have the technology to capture it in color, or something else entirely? | [
"You are probably talking about some kind of electron microscopy (most likely ",
"Scanning Electron Microscopy",
"). These images are grayscale because they are simple intensity maps.",
"Now, you are completely right in thinking that it would not work to acquire images of ~30 nm components using standard opti... | [
"Thanks, I figured that below the wavelength of visible light, we couldn't \"see\" anything, but I didn't know if that was actually true. I appreciate the response! Thanks for the information!"
] | [
"You cannot estimate the wavelength of the emission directly from the size of an emitter like this. Single atoms are smaller than a nanometer and can very well emit in the visible."
] |
[
"I found these circles on a map which are weird formations; what made them?"
] | [
false
] | I'll try to make this brief. I was looking on a local satellite map in my area, Thumb of Michigan, USA, and I found several circles, all in the area, if not the same section. Some of it's state land, so I hiked out there to see what it was. There's no trails (new or old distinguishable) to any of these. They're a secti... | [
"Considering the location, I would suspect they are collapsed pingos from the era when the land was tundra at the end of the last glacial era. ",
"Pingos",
" are hills that rise in permafrost zones when a pocket of underground water freezes and heaves the land up in to a small conic shaped hill. If/when the are... | [
"There's an area near me that has a fair number of earthworks that look like these, called ",
"Mounds State Park",
". The ones at Mounds are Native American ceremonial mounds, dating back to the Adena culture in 1000-200BC.",
"Based on some very brief research, there ",
"have been Native American mounds ide... | [
"Not all permafrost zones. Only continuous permafrost. And they are a periglacial landform, not a glacial landform. As some pingos degrade, they can form rings ( I call them Ringos), but the rings tend to still have some relief or elevation. Also you should note that in areas that are prone to pingos, they still ta... |
[
"Do any traits really \"skip a generation\"?"
] | [
false
] | And if so, what exactly is going on with the genes to cause this? | [
"There are no traits that will \"reliably\" skip generations in the way you're thinking (or at least the way it seems like you are), principally because traits aren't inherited in a strictly vertical fashion, only genes are.",
"Your grandparent had a particular trait as a function of some of their genes which the... | [
"X-linked traits in humans (and similar phenomenon in other organisms) could skip females but affect males. Female humans have two X's as their 23rd pair of chromosomes. If one of them has a trait that is recessive, say color blindness (an actual X-Linked trait), they more-than-likely have a normal second X chromos... | [
"It should be possible with any recessive trait. If your parents each have one. If both parents have one copy of the gene for a recessive trait, they won't have the trait, even though one each of their parents (but not both) could have had the trait. From there you have 1/4 chance of having the trait."
] |
[
"What two creatures are most closely related genetically, but look the most different physically?"
] | [
false
] | null | [
"This is a little bit of a cheeky approach to your question: the thing most genetically similar to any organism is itself (or its clone/identical twin). A caterpillar is genetically identical to the butterfly it will become, but is vastly different physically. The same goes for any animal with metamorphosis: frogs,... | [
"The elephant shrew is more closely related to an elephant than a shrew. They both belong to the Afrotheria group, which also includes aardvarks, while shrews are more closely related to hedgehogs and some moles. []() ",
"Elephant Shrew",
" "
] | [
"Like ",
"u/empire314",
" and ",
"u/WildZontar",
", the first thing that came to my mind was dogs. I'm also going to throw out ",
"Hippos and Whales",
" as very \"different\" but closely related species. But the cool thing about dogs is that, for all their variation, they are a single species."
] |
[
"Does cooking eggs and red onions create a chemical reaction?"
] | [
false
] | I love eggs, I love onions. I even love eggs and onions together when they’re cooked separately. But once they get put together to cook something seems to happen and it creates a completely disgusting taste. Any idea why this could be? I know cooking and baking is all just chemistry so I’m sure there must be some expl... | [
"The moisture being release from the onions is steaming your egg and making it gross. Onions have a lot more sugar in them than you might think, and a ton of water, so it's always best to caramelize them before adding them to an egg dish; you've deepend the flavors in the onion itself and cooked out much of the wat... | [
"Thank you for this!! It makes complete sense and I feel that you have accurately articulated the process. Now I’m hungry for some eggs and caramelized onions!"
] | [
"I cut my onions as small as I possibly can. I basically slice the onion to 1/8 inch (or smaller) then dice them as small as I can. This makes them caramelize faster and then I add butter and scramble the eggs. The small onion chunks blend in with the eggs and taste amazing."
] |
[
"How safe are medical trials for flu/cold medication?"
] | [
false
] | This one ( ) for instance is offering £3000 ($4655) to spend 2 weeks in a 'flu camp'. Is this safe? In general how badly wrong can medical trials go? | [
"Disclaimer: I'm not a clinical researcher but I work with people who are so I will try my best here.",
"First off, every good researcher is concerned with the health of the participants above anything else. This means that if you, in the course of the study, develop a condition that could be dangerous, the resea... | [
"This means that if you, in the course of the study, develop a condition that could be dangerous, the researchers will stop any further research on you and ensure that you receive medical care",
"The important caveat to this is that depending on your location, the researcher, and company backing the research, may... | [
"I was thinking of giving this a go as I'm having trouble getting work and this doesn't sound like an overly bad way to make some money whilst helping to increase the development of flu vaccines. Would a flu trial carry the same risks as the TGN1412 did, as that was aimed at B cell chronic lymphocytic leukemia (B-C... |
[
"If the human race is destined to become one genetic melting pot courtesy of globalization, does this state not lead humanity in the direction of the Irish Potato Famine?"
] | [
false
] | Genetic diversity leads to strength, but if we all become a universal "race" with extremely small genetic pools, aren't we likely to fall victim to some type of evolutionary pitfall eventually? | [
"Just the opposite. Having a large interbreeding population will lead to greater genetic diversity."
] | [
"I've heard different before",
"You've heard it wrong. Mixing of genetic traits from different populations leads to new combinations and therefore more overall diversity."
] | [
"Boom! Everyone except me and Angie Varona just died. Time to repopulate the Earth. I'll do my best to have as many children as possible, but, eventually my progeny will have to start inter-breeding in order to keep the human race alive. What do you think this will do to the genetic diversity of our gene pool?"... |
[
"Could a computer which is encased in ice continue to function."
] | [
false
] | From what I've read there are few parts of a computer which have to be moving. Those that are (HDD, case fans, CPU fan, GPU fan,) These can be replaced or removed in this scenario. I.e SSD for HDD. (Fans can be removed because the cooling will be accomplished by an outside source in this case probably a freezer to keep... | [
"Honestly I'd go with mineral oil not water but you're real issue is that a solid (ice) doesn't transmit heat any where near as well as a liquid or gas does. This means that it is actually an insulator and you will overheat the machine even if you don't melt the ice.",
"edit: some solids do transmit heat well (... | [
"yes it would. probably faster. the HDD is sealed to keep dust out, so it would also keep water ice out. the cpu would be more efficient at the lower temps. if you could keep the water from shorting out where the ice melted at its contact point with the cpu, north bridge, south bridge chip, etc.{where it gets hot} ... | [
"What I say is purely out of opinion and should not be taken into actual facts bu:",
"1) The computer would be producing large amounts of heat in every area, so there is the problem of dealing with the ice to melt, unless you have encased every piece of the computer in a container.",
"2) The ice will eventually... |
[
"chemical reactions at a high velocity"
] | [
false
] | [deleted] | [
"This may not really be the answer your looking for - but the ",
"of a material is related to how fast its molecules are moving. Temperature has a major effect on chemical reactions, since things are moving, colliding and mixing much more rapidly."
] | [
"Well, then you're not talking about relative velocities but implying an actual 'absolute' velocity. ",
"The contents of a box, isolated from its surroundings and moving at constant velocity, will have the exact same chemical properties no matter how fast it's moving relative anything else."
] | [
"Well, then you're not talking about relative velocities but implying an actual 'absolute' velocity. ",
"The contents of a box, isolated from its surroundings and moving at constant velocity, will have the exact same chemical properties no matter how fast it's moving relative anything else."
] |
[
"How high can a building be before you can no longer see the top?"
] | [
false
] | Standing at the base of the building. Also, provided there is no fog or visual obstructions. (A smooth surface) | [
"Lets see.",
"The human eye has a (ballpark) resolution of ",
"2 arc minutes",
".",
"Lets use rectangular prisms the same size as the WTC towers, which were ",
"64m square",
".",
"Some simple trig:",
"tan(2 arc min *0.5) = (64m*0.5)/x",
"x = 32m / tan(1 arc min)",
"x = 110008m = 110km = 68.4 mil... | [
"Assuming the building is a rectangular solid here.",
"If it is taller than your eye level, you will be unable to see the \"top\". If you're referring to the side of the building at the top, it will be visible from the bottom no matter how tall the building is, though it will subtend a smaller and smaller angle o... | [
"surely there would be a point when so few photons from it were hitting your retina that it would effectively be invisible. do you know what point that would be?"
] |
[
"What determines \"directionality\" in Pavlovian conditioning?"
] | [
false
] | In the classic example of the dog an the bell, why does the bell cause drooling and not vice versa -- the dog drooling makes it "imagine" a bell? Or, to use a more recent example, a redditor claimed that he had to poop when he ate chocolate M&Ms because his mother had unknowingly conditioned him. Why does he not crave ... | [
"I realize the second problem, which is why I followed up with two examples that don't involve animals.",
"As for your first problem, that's something I'm trying to figure out with the last example. You have two stimuli and you're trying to associate one with a certain emotion -- what determines which gets which ... | [
"I realize the second problem, which is why I followed up with two examples that don't involve animals.",
"As for your first problem, that's something I'm trying to figure out with the last example. You have two stimuli and you're trying to associate one with a certain emotion -- what determines which gets which ... | [
"Finally a question I (think I) can answer. ",
"In Pavlovian conditioning there are three concepts that play an important role, 1) the unconditioned stimulus, 2) the response and 3) the conditioned stimulus. What Pavlovian conditioning does is replace the original relationship between an unconditioned stimulus (t... |
[
"How/why do separate species breed?"
] | [
false
] | null | [
"You're placing a lot of stock in the intellectual reasoning of creatures with brains sometimes the size of a grape. \"Because sex\" is sometimes all the reason wild animals need. It was there, it was available. ",
"Not even wild animals, some pets will have sex with a mate, a cushion, and their owner's leg with ... | [
"Coyotes are generally loners. Wolves travel in packs. If a coyote approaches a wolf pack they are more likely to be attacked than greeted.",
"But if a coyote approaches a lone wolf, and one of them is in heat, they can get it on. A wolf/coyote/dog in heat produces produces powerful phenomenons, enough to dri... | [
"As a point of comparison, Alfred Kinsey found (in the 1940s) that something like 40% of rural men in America had fucked a farm animal at least once."
] |
[
"Why is cloth darker when it gets wet?"
] | [
false
] | null | [
"In dry cloth, light gets scattered and reflected mainly by the particles on the surface. In wet cloth, some of the light gets carried into the material by the water, acting a bit like fiber optics. The end result is that less light gets reflected or scattered back.",
"Consequently, this same phenomenon is why ... | [
"That actually has to do with thickness and density. All storm clouds are saturated water vapor (there are no \"dry clouds\" in our atmosphere), but the density at which the vapor is held determines how much light is absorbed. "
] | [
"Density != Tensile strength"
] |
[
"why does there appear to be a tinge of blue light at the edge of white light?"
] | [
false
] | i am sorry if this has been answered before but a few nights ago while leaving work i noticed the moon was particularly bright. around the edge of it, the moon's light took on a bright blue hue. i saw this again when passing a nearby streetlight and i realized i have never really noticed this phenomenon before. what ca... | [
"This actually has nothing to do with Doppler shift. The shift in frequency is related to the speed of the retreating or encroaching body. It would have to be moving quite fast to be noticeable. ",
"The phenomenon is the same reason the sky is blue: Rayleigh Scattering. Blue light is more effectively scattered by... | [
"Lens bend light. A perfect lens bends all wavelengths equally. Imperfect ones will show colour aberrations. The blue component of white light is bent at a slightly different angle than the rest of what makes the white light. Eyes have lens inside. ",
"In digital cameras, it is known as purple fringing. "
] | [
"so when i saw the blue light from the moon, would it have been because of my eyeglasses? or maybe because of some misalignment in my eyes perhaps?"
] |
[
"In outer space, how well will helicopter' s and drones fly?"
] | [
false
] | null | [
"They won't. They require air (or some other gas) to control the direction of motion."
] | [
"It's not a complete vaccum."
] | [
"With respect to the devices mentioned, there's effectively nothing to push against. ",
"u/Rannasha",
" is correct. This is why we use rockets instead of jets and propellers for spacecraft."
] |
[
"Why doesn't red safe lights in a dark room affect the photos being developed?"
] | [
false
] | I was recently introduced to a dark room used to develop black and white photos in a photography course. The instructor said that only a dark red light is the only light source that doesn't affect the photos but couldn't offer an explanation as to why. | [
"B/W photography components, films and papers, are sensible only to blue light wavelength.\nRed and green/yellow safe lightbulbs are specifically designed to avoid any blue wavelength emission (they aren't common colored lightbulbs)."
] | [
"Brightness is not too important actually unless you are going to have the paper out of the safe for more than a few minutes."
] | [
"Brightness is not too important actually unless you are going to have the paper out of the safe for more than a few minutes."
] |
[
"Is pressure dependent on volume or area?"
] | [
false
] | My question is: if you had two rectangular containers with the same volume but with varying lengths for the sides such that the internal area was different for both and you pumped in the same amount of gas at the same temperature, which would have a higher pressure, the one with the larger or smaller area? | [
"The pressure will be the same in each container. "
] | [
"I'm not sure what you mean by internal area, but for an ideal gas, if the temperatures and volumes are identical, then the pressure will be as well. The pressure depends on the volume, not the specific dimensions or shape of the container."
] | [
"Well, to answer your question, it is the volume on the inside of the object that matters. You can see this from the ideal gas law:",
"PV=nRT, where P is pressure and V is volume, n is molecular mass (I think?), R is a gas constant, and T is temperature.",
"But I think you are confusing your terms. What you kee... |
[
"Do microwave transmission dishes heat the air in front of them? Is there enough heat to cook birds and/or turn snow/rain/fog into steam?"
] | [
false
] | null | [
"Short answer is no. Long answer is microwave transmissions heat up water molecules just like a microwave oven but there is very little power so it is almost nothing. A microwave oven uses 800 to 1500 watts of power do heat water. While a satellite dish is directional, the wattage is less than 30 watts and it is a ... | [
"Well, except that was a radar dish, not a microwave communication antenna. Radars work at much higher power levels - often in kW range, especially the ones used to track airplanes and ships (military)."
] | [
"That’s actually how they invented microwave ovens, a guy was standing in front of a dish and his chocolate melted ",
"However microwaves don’t really heat the air, they only heat mostly solid stuff that contains liquid water, so the air isn’t heated, probably doesn’t cook birds, but it might heat them up a bit, ... |
[
"How do allergy shots work?"
] | [
false
] | How do allergy shots differ from just being exposed to the allergen? I’ve read that the shots give a tiny dose of the allergen, not enough to cause a full blown reaction, but enough to gradually desensitize the body to it. But if I’m already being bombarded with the allergen, say cat dander and dust mites, then what go... | [
"In the short term allergy shots only makes things worse. ",
"Allergy shots happen weekly for years slowly building up your body’s ability to ignore increasing amounts year round, not just in season. They have you wait around after each shot to ensure you aren’t having a severe reaction, in which case they would ... | [
"You’ll probably progress faster since you already have constant exposure. The increases they give you will make you feel worse, but over time your body adjusts to a new tolerance level that is helping your body to not react once you reach maintenance levels."
] | [
"Makes sense! What if you’re allergic to something that’s around you year-round, like dust mites and animal dander?"
] |
[
"Where is all the anti matter?"
] | [
false
] | is there anti-matter naturally in the universe? if so if it touches matter doesnt the matter and anti-matter violently react. even though space is "empty" its not really empty space is not infinite and therefore cannot be "empty" therefore any anti matter would immediately react right? also if the big bang created all ... | [
"we're working on it."
] | [
"Working on it. Of course. Making sure the public maintains sufficient interest in the sciences to demand funding so that the people who do the work and don't waste their time on reddit will actually be able to do their work ;-)"
] | [
"This is a great question and touches on some of the unsolved problems in today's physics. Many people think: if the big bang was truly an expansion from the universe that observed pair production, then equal amounts of antimatter and matter should have formed; further, these equal amounts should have annhilated to... |
[
"Why dont we get rid of our nuclear waste by injecting it in the mantle?"
] | [
false
] | From here | [
"Well the biggest problem in that is that we've never drilled into the mantle. Drilling that deep is incredibly difficult. Then getting radioactive waste down there is not simply a case of dropping it down the hole."
] | [
"They drilled 12,000m (not km) and had to stop due to both projected technical issues and funding constraints.",
"From ",
"wikipedia",
":",
"The continental crust is typically from 30 km (20 mi) to 50 km (30 mi) thick",
"So it's not just \"a few more\". Actual thickness will vary with local geology but s... | [
"This. And, just to put these sizes in context - the diameter of the Earth is 12,742 km. And it's not quite round, so there's actually a 43 km difference between the polar diameter and the equitorial diameter. We've drilled 12km."
] |
[
"Hi!! I have to think of experiments with magnets or rainbows to be done with kids of 10-12 years old. Can you help me?? :)"
] | [
false
] | null | [
"I would probably find some iron, nickel and cobalt magnets to see how each of them differ in strength of magnetism. And then show them neodymium magnets, how how much more powerful they are! The explanation of why they differ might be beyond them though...",
"As for rainbows, show hem how to split white light in... | [
"Ferrofluid",
" can be messy but is a cool was to see the interaction between surface tension, gravity and magnetic fields.",
"A ",
"magnetic linear accelerator",
" can be fun and easy to build if you can find the right sized magnets and metal balls.",
"Eddy current effects",
" are also really fun with ... | [
"When I was little we made a super powerful electro magnet. "
] |
[
"This may be a dumb question, but how does a Lion know he can kill me, but a duck doesn't?"
] | [
false
] | null | [
"Lions have evolved to have the instinct to attack certain kinds of prey or in certain situations where they feel threatened. Humans are relatively slow and defenseless on their own.",
"Ducks actually can be aggressive, but they have evolved to fear larger animals which they sense to be a threat."
] | [
"An animal doesn't need to \"know\" it can kill something to fight - think of a wasp.",
"There is a ",
"BBC video",
" showing 3 tribesmen scaring 15 lions away from a kill. I doubt 3 gnus (or other human scale prey animal) would be able to pull this off. These 15 lions don't \"know\" they can or can't kill th... | [
"Most animals, lions included, avoid humans in almost every instance if its possible. ",
"We can consider this conjecture (I saw it somewhere but I can't remember where), but I think the reason for animals aversion to humans is we've been so dominant as a species for so long that the animals which weren't scared ... |
[
"How will communication between humans evolve in the future?"
] | [
false
] | [deleted] | [
"It is currently possible to crudely reconstruct what someone is seeing by scanning their brain with an MRI. In the future, this technology may be perhaps be shrunk to something you can wear and improved to something that can actually record your thoughts, and you could use that to send thoughts to others."
] | [
"But you'll still be restricted to 140 characters."
] | [
"Well, technology will most likely define the development of communications (duh). ",
"I think two problems might be crucial in the future (and present I guess).",
"Inadequacy of education system. The world is already too complex for education system to guarantee that students will adequately comprehend it. It ... |
[
"How does receiving the rabies vaccine AFTER being exposed to the virus work?"
] | [
false
] | It's my understanding that vaccines inject a population of the virus that is weakened or dead in order for the body to learn to produce antibodies. How is this effective when the body is already exposed to a live virus, such as in the case of rabies exposure? | [
"Rabies infection is therapeutically treatable with vaccine because it is slow to reach the immune system. It gets into neurons at the site of the bite and moves along their axons to the brain where it causes the disease. The rate of this movement has been measured at 3mm/hr and until it reaches the central nervous... | [
"When a person is infected by the rabies virus, it is usually through a bite to an extremity like a hand or foot. The rabies viruses spreads throughout the body through your nerve cells, meaning that it takes a relatively long time (days, weeks, even months) for the virus to spread from the initial point of infecti... | [
"I'm not certain exactly how fast the virus spreads through neurons, so I can't say. Maybe even the time it takes to spread through a few inches of nerve tissue is enough time for the vaccine to have effect, I don't know."
] |
[
"In terms of evolution, do beneficial traits often get passed down with irrelevant/negative traits?"
] | [
false
] | As a made up example, a genetic trait makes mice super fertile (beneficial) but also gives them lighter pigment spots in their fur (irrelevant). What is the implication of this in humans? When a gypsy tells you that you have a short life line on your hand could she actually be telling you that you have a high risk for ... | [
"Something to consider is that sometimes what looks like a negative trait can actually have benefits that may increase the likelihood of it being passed on.",
"For example, Sickle Cell Anemia is a genetic condition that causes your red blood cells to be the wrong shape, and causes chronic pain and vessel blockage... | [
"What you mean is generally called gentic draft or hitchhiking effect and it can cause all kinds of interspecies (and sometime intraspecies) variation.",
"As a simple example from ",
"wikipedia",
"The Y chromosome does not undergo recombination, making it particularly prone to the fixation of deleterious muta... | [
"The general answer is yes, there are traits that tend to be correlated. ",
"There are two mechanisms for this.",
" ",
"The first is linkage. Genes are linked if they are on the same chromosome, and traits associated with genes close together (closely linked) tend to be inherited as a group. For example, red ... |
[
"Is it possible to make a fan using sound waves?"
] | [
false
] | For example, if you get a sub-woofer, you can feel air come out. Could you make a sound wave to low for us to hear, but displace enough air to use as a fan or air conditioner? | [
"I'm an audio engineer so I like to keep knowledgeable about the latest gear."
] | [
"The opposite's possible.",
"http://en.wikipedia.org/wiki/Rotary_Woofer"
] | [
"Actually, subsonic speakers can be made with fans which will produce frequencies far below 20hz, down to a static pressure differential.",
"http://en.wikipedia.org/wiki/Rotary_Woofer"
] |
[
"If disorder increases over time how does that explain complicated natural objects?"
] | [
false
] | So my example is the tree i see outside my window or the human brain. The way i understand it is that organized patterns of molecules came from seemingly unorganized material. Is there something i'm not getting? | [
"Disorder does not increase over time.",
"Entropy increases over time, which is only the same as disorder in a few situations.",
"Entropy can locally decrease by increasing elsewhere in the system."
] | [
"Well put. Thread over."
] | [
"Thanks."
] |
[
"Is it possible to build a telescope that could see the surface of extrasolar planets?"
] | [
false
] | Theoretically, could we find an earth-like planet and then build a telescope to read the newspaper over a Xoblorgian's shoulder? | [
"Yes, but it would have to be really, really large. Or (more likely) be an interferometer, with a huge baseline. ",
"There is a simple equation for working out the resolving power of a telescope:",
"sin(angle) = (1.22*wavelength)/diameter",
"Where the angle is the separation between features, diameter is the ... | [
"Not possible in the near future, however, we can get a lot of information even if we can't see the surface. For example, we can analyse the spectrum of the system when the planet is in front of the star and behind the star. The difference in the spectrum can tell us about the chemical composition of its atmosphere... | [
"Oh yeah, and I'm definitely not knocking any of that other stuff, much of which yields more useful datal than direct imaging anyway. This question is more about whether or not we can get a \"money shot\" of the surface an extrasolar planet. Think more \"cover of Time\" less \"Look at all this useful data!\""
] |
[
"How did such large, or little, quantities of Hydrogen, Oxygen, and Carbon, develop in the formation of Earth, but not other planets?"
] | [
false
] | Why doesn't Mars have such abundant Oxygen or Hydrogen deposits? Did it at one time, but they were whisked away when the atmosphere was obliterated? Why we have such egregious amounts of Hydrogen in our atmosphere, unlike Jupiter, with it's 88–92% hydrogen by percent volume? To put it simply, how did the planets gai... | [
"Mars does have abundant oxygen in the form of silicate.",
"Mars and Earth are both too small (low escape velocity at ambient temperature) to retain hydrogen gas (high average velocity) for any geological period of time. They can hold oxygen (lower average velocity), but it is a highly reactive gas that must be ... | [
"To add to this excellent answer - the only reason earth has such a dense atmosphere is that it is geologically active and massive enough to replenish and hold on to its atmosphere. Mars is much smaller than earth, with correspondingly weaker gravity, hence its atmosphere was lost more easily. Its size also meant i... | [
"I want to say that the active history on Mars is pretty under constrained. There are people arguing that the Shergottites are ~500 million years old which would suggest some recent magmatic activity. I also want to note that if Earth were simply losing heat by thermal diffusion you get values for global heatflow ~... |
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