title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Does freezing dead bodies kill any diseases they may have?"
] | [
false
] | [deleted] | [
"Bacteria are highly resistant to freezing and viruses don't care at all. The usual storage conditions for bacterial culture samples in the lab are -78°C, they stay viable at that temperature for years. So, freezing doesn't help much in that regard. What freezing can do is killing multicellular parasites, though. B... | [
"Basically the more complex the organism is the more that can go wrong with it, and the more extreme environments will adversely effect it."
] | [
"Aye. And bacteria that can sporulate have an additional advantage there, since in their dehydrated state, ice formation isn't a concern."
] |
[
"If I were in a helicopter during a very large earthquake, would I be able to see the seismic waves moving across the ground?"
] | [
false
] | I don't think I would be able to, but I was thinking about it. Second, how large would it have to be in order to see the ground move from a normal helicopter flight? | [
"No, these waves are not considered to be detectable by the human eye. Although some people claim to have seen them this is more likely to be caused by the stroboscopic effect when the seismic waves disturb the air above them in synchronization. ",
"See here.",
" And cause an illusion or mirage. This effect wou... | [
"these waves are not considered to be detectable by the human eye. ",
"Is that because of their low amplitude, their high speed, or both?"
] | [
"Almost certainly not.",
"The reason being that the wavelength of these waves is on the order of kilometers, and the amplitude is on the order of meters. If you're far enough up to see the wavelength, you're too far away to see the amplitude. They're also very fast moving (km per second).",
"Close enough to the... |
[
"Why do some people sneeze multiple times in a row?"
] | [
false
] | Lately at work I've noticed how differently some people sneeze from one another. When I sneeze, which is often triggered by sunlight, it is always one big boisterous sneeze. Pretty loud and violent reaction relatively speaking. Sometimes I might sneeze once and then sneeze again 5-10 seconds later. My boss on the o... | [
"This comment gets to live",
"."
] | [
"Just a heads up, if you're writing \"u\" in your comment in place of the second-person pronoun, the comment probably isn't appropriate for ",
"/r/askscience",
". Also, you make use of personal anecdote, and even admit your comment is based off \"speculation.\" You provide no supporting links, and in fact you d... | [
"Just a heads up, if you're writing \"u\" in your comment in place of the second-person pronoun, the comment probably isn't appropriate for ",
"/r/askscience",
". Also, you make use of personal anecdote, and even admit your comment is based off \"speculation.\" You provide no supporting links, and in fact you d... |
[
"Why is both helium 3 and deuterium required for a fusion reaction?"
] | [
false
] | I was watching a video ( ) (yep I’m not too versed) and they said that both deuterium and tritium or helium 3 was required for the fusion reaction. Why can deuterium not fuse with itself? If the plasma was hot/dense enough would this be possible? | [
"I didn’t watch the video, but deuterons can definitely undergo fusion with other deuterons. DT fusion has a higher Q-value, which means more total energy released, but DD is possible as well.",
"The Coulomb barrier depends much more strongly on Z than on A, so since deuterium and tritium and both isotopes of hyd... | [
"Tritium can be bred while the reactor is operating, so I think that should be taken advantage of in a fusion reactor for power generation."
] | [
"Take a look at this reaction rate chart, which was made using data provided by the US Navy's Plasma Physics Division: ",
"https://upload.wikimedia.org/wikipedia/commons/d/d0/Fusion_rxnrate.svg",
"Keep in mind the y-axis, fusion reaction rate, is in log scale (so is the x-axis, temperature). Until you reach tem... |
[
"How close to the earth was the moon (estimated to be) originally?"
] | [
false
] | Assuming the impact theory is correct, what was the likely original distance from the earth our satellite originally was? Would it have been noticeably larger if we were able to view it? Sorry for the kind of specific questions, I just find stuff dealing with the ancient earth (continental shift, etc) interesting. | [
"The simulations also imply that at the time of its formation, the Moon sat much closer to the Earth - a mere 22,500km (14,000 miles) away, compared with the quarter of a million miles (402,336 km) between the Earth and the Moon today. ",
"[Source]",
"Yes, it would have looked much larger."
] | [
"That also means that the length of the day on Earth was much shorter, due to conservation of angular momentum. I've read that it was about 6 hours long."
] | [
"I can give you a highly rounded average that is definitely not the exact number, but it's relatively close to it. ",
"The Moon moves away from Earth at an average of 3.8cm / year. Multiplying that with the Moon's age gives us 171,380 km. ",
"Take that from the current average distance to the moon which is 384,... |
[
"In light of the European ban on neonicotinoids, how strong is the science supporting their link to colony collapse disorder?"
] | [
false
] | [deleted] | [
"tl;dr There is very strong evidence that neonicotinoids seriously harm bees, but only weaker evidence that this is the sole cause of colony collapse.",
"The Guardian",
" has a summary of some of the issues, but I'll make a few comments here also.",
"It isn't a total ban, only ",
"three neonicotinoid insect... | [
"I don't think you're being entirely fair to DulcetFox.",
"The wide spread use of neonicotinoids is relatively recent, so could explain the timing. Unfortunately there are lots of other things that both show correlation and which could logically be causes. Climate change, mites, the use of high fructose corn syru... | [
"I don't think you're being entirely fair to DulcetFox.",
"The wide spread use of neonicotinoids is relatively recent, so could explain the timing. Unfortunately there are lots of other things that both show correlation and which could logically be causes. Climate change, mites, the use of high fructose corn syru... |
[
"If milk contains lactose, why isn't milk naturally sweet?"
] | [
false
] | I have been told lactose is a sugar just like glucose etc but why is milk not naturallly sweet | [
"Not all sugars are sweet. Sweetness levels of various sugar and nonsugar compounds are measured relative to sucrose, and lactose falls pretty low on the scale: ",
"http://www.elmhurst.edu/~chm/vchembook/549sweet.html",
"\nSome substances are sweeteners without being sugars. For instance, Neotame is several tho... | [
"I think the interesting question is why do you not find it sweet. I personally find milk very sweet. ",
"There was a study done on milk sweetness preference: ",
"http://www.sciencedirect.com/science/article/pii/0031938485901507",
"They found that obese people preferred less sweet, higher fat milk than norm... | [
"Lactose is made of glukose and galactose. Only when the bond in the molecule of lactose is broken, we can feel the sweetness. Usually we don't keep milk in mouth long enough to let this bond break. If you've ever tried warm milk then you probably noticed it's sweet."
] |
[
"Would a rock placed in a vacuum erode?"
] | [
false
] | null | [
"Within the solar system, rocks in vacuum are slowly eroded by solar wind, micrometeorite impacts, and photochemical reactions on their surface. A completely isolated rock kept in a vacuum with literally no other mass might experience some slight erosion due to internal radioisotope decay, but this would slow over ... | [
"Quantum tunneling makes spontaneous fusion of lighter elements possible (though by no means likely). ",
"It stops at iron because it's the point where fusion is impossible with no further energy input."
] | [
"I had a chemistry teacher tell the class that a solid in a vacuum would very slowly sublimate over time. I know the process would be very slow, but over the course of millions of years in a vacuum would that have an impact?"
] |
[
"Does weather have any influence on geothermal energy?"
] | [
false
] | Geothermal has much to do with the convectional flow of heat inside the earth, but what role does weather play in it? | [
"Well, since no one has answered your question, I'll give it a shot.",
"Geothermal is just heat. To actually get anything done with that heat you have to convert it to work. Getting work from heat relies on a difference in temperature. Since the temperature of the geo source won't vary much, a lower air temperatu... | [
"It's a good question, and I understand your logic, but weather has essentially zero effect on geothermal energy. Firstly, you have to look at the average geothermal gradient on the continental crust which is 25 C/km. This means that on the average area of land, you will have to dig 1 km down before the temperature... | [
"This largely depends on what sort of geothermal energy source one considers: shallow geothermal energy is effected by weather and the daily variations in temperature, while deep geothermal energy is largely independent of those factors. ",
"Shallow geothermal energy means, that one would bury a geothermal device... |
[
"Is it possible to divide the frequency of the light?"
] | [
false
] | In electronics there are devices named "frequency dividers" which basically reduce the frequency of the incoming signal by counting zero-crossings. For example 1000 Hz oscillation on the input could be turned into 500 Hz. Would it be possible to sense the light as an oscillation and consequently divide its frequency to... | [
"Yes, it is possible to reduce or increase the frequency of light. See ",
"Nonlinear Optics",
". Dividing the frequency exactly in half would be a special case of ",
"spontaneous parametric down-conversion",
", but there are many other ways to use one or more photons to create other frequencies.",
"Nonlin... | [
"Nonlinear optical processes are generally quite inefficient",
"It depends, doesn't it? Depending on the process they can be very efficient. Spontaneous parametric down-conversion from your example is very inefficient, but second harmonic generation within an optical cavity can reach efficiencies that exceed 50% ... | [
"Yes, there are cases where it's efficient. But the nonlinear susceptibility, chi",
", is typically around 10",
" per order, implying a base efficiency of around 1/10000 per additional photon. If we're clever we can do better."
] |
[
"Could we deplete the earth's core of heat?"
] | [
false
] | Geothermal energy confuses me and I couldn't figure out how you could deplete the energy from the PV=nRT equation in the earth which causes it to have a greater Temperature due to pressure. If you removed that Temperature wouldn't the pressure still be the same because the force of gravity would increase it? I'm 100% I... | [
"Could we deplete the earth's core of heat?",
"No. Not in any realistic scenario. We are too puny. Also, the geothermal energy is slowly dissipating in space even without our help.",
"The equation you are using is about ",
" gases, and the Earth core is neither of those.",
"More importantly, pressure by its... | [
"So could you explain the reasoning behind the Temperature b/t pressure, and how it would keep putting pressure in it for a long time it would have an infinite amount of heat? Sorry I have very little understanding of the topic. "
] | [
"To pressurize something you either add heat with constant volume )which will increase temperature), add material with constant volume (which will increase pressure), or reduce volume (also increases pressure). But keeping something under pressure alone will not retain heat, because to increase pressure you have to... |
[
"P-value and mean doesn't add up. Do I always follow the p-value?"
] | [
false
] | null | [
"Can you clarify what you mean when you say the p-value and mean don't add up?"
] | [
"i used \"add up\" as a figure of speech.\nThe means for both condition just appear to be on average.\nTrust= 5.66, Distrust= 5.05. \nIt's that huge of a difference yet the p-value is =0.03. \nWould I always follow the p-value regardless of how questionable the mean/average looks? "
] | [
"If I understand what you're asking, I can clear up the misunderstanding. The mean of the scale doesn't matter here. What the t-test is doing is testing the means of two groups to determine if they are different. In this case, you're investigating the trust condition compared to the distrust condition.",
"The t-t... |
[
"Does gravitational time dilation impact a star's lifetime?"
] | [
false
] | Does gravitational time dilation impact a star's lifetime? If so, is there a "normalized" stellar lifetime which takes this into account? What sort of observational evidence, if any any, suggests that nuclear processes in the star happen faster/slower than we would expect in the lab? | [
"Does gravitational time dilation impact a star's lifetime?",
"Not really.",
"In fact, ",
"I did the calculation over the weekend that time dilation between the earth's surface and the sun's surface is only a matter of 66 seconds per year.",
"The time dilation factor grows like 2GM/R, and if the mass grows ... | [
"Yeah, time dilation is really significant for them. For a neutron star, the flow of time looks roughly like ",
"this",
". The y-axis is the flow of time, 1 being normal, and zero being stopped. The x-axis is distance from the centre of the star. In simulation units, the star has roughly a radius of 2. As you c... | [
"66s/yr amounts to about 20,000 yrs over a 1 solar mass star's lifetime (10By)"
] |
[
"Why can Iodine diffuse through a cell membrane?"
] | [
false
] | I've searched google and my results showed that Iodine would diffuse through the cell membrane. This seems counter-intuitive to me because of its negative charge and the impermeability of almost every other ion (H+,Cl-,Mg++,Ca++, etc.). I was hoping someone here could answer my question. Thanks! | [
"Keep going. Iodine is a solid at room temperature and pressure."
] | [
"Keep going. Iodine is a solid at room temperature and pressure."
] | [
"The sodium-iodide symporter",
" might be of interest here.",
"Also, just to confirm - the citations you found of the cell membrane's permeability to iodide were for proper cell membranes (or physiologically relevant mimics), correct? If you could share them, we might have a better idea how to address your inq... |
[
"Electron cloud question - Do they appear and disappear faster than light?"
] | [
false
] | So, in the electron cloud model, rather than orbiting the nucleus of an atom, electrons actually appear and disappear incredibly quickly around the nucleus (in the shape of valence electron shells.) I was once told by an astronomy professor that electrons in an electron cloud don't really travel, they just reappear som... | [
"The electron cloud model is a little like Newtonian mechanics in the sense that it ignores the speed of light. It is assumed that the speed of light is infinite. If you want to account for relativistic effects, you need to abandon quantum mechanics and do quantum field theory, specifically quantum electrodynamics.... | [
"Electron clouds are basically ",
"standing waves",
" of electron. The electron isn't in any one place in the cloud, it ",
" the cloud.",
"When an electron is bound to a nucleus in a particular orbital, we say it's in a momentum eigenstate. That means its momentum is well defined, but other properties, su... | [
"Actually the uncertainty principle doesn't really say that we can't know the position and momentum of a particle at the same time. It says that when a particle has a well defined momentum, it ",
" a position, and vise versa. There's not some \"hidden\" information that we can't observe. There just isn't more ... |
[
"Are GMOs actually bad for us?"
] | [
false
] | null | [
"In short, there's not enough research to be conclusive!!!",
"IMO: I'm fine consuming GMO's that are the process of selective breeding such as corn and wheat which have been bred to be bug resistant or drought tolerant. I'm not exactly sure about the more intensively lab manipulated foods. ",
"Please remember... | [
"Modification is only bad or good on the basis of each specific modified trait. \nAs far as health goes, I'm not aware of any evidence that any GMO has deleterious effects on human health. \nMonsanto et al may have obscenely reprehensible business practices, but their food is probably fine for you and there's absol... | [
"There is no evidence as such, however opponents of the GMO industry believe that problems could arise years in the future. There is no easy way to test that hypothesis. GMO food has been around for awhile and no adverse effects have been found though."
] |
[
"How close are we to getting rid of the aging of skin or at least the appearance of aging?"
] | [
false
] | Can a laser be made to get deep enough and remove a lot of skin to reveal newer, better-looking skin? Or is that "newer skin" damaged (DNA damage I guess?) to where it will just look old also? , I saw a program on TV about a girl that got an infectious, flesh-eating disease of the skin (I think it was Mystery Diagnosis... | [
"A lot of the visible signs of aging (wrinkles, sagging skin, etc) are a result of elastin and collagen slowly breaking down, and a steadily decreasing efficiency of replacing them. Elastin is what's responsible for the stretchiness of your skin, unsurprisingly. Some people have a lot of it and are able to do all s... | [
"Take a look at ",
"this",
"This describes some of the causes of the lack of collagen. Collagen formation is partially controlled by the hypothalamus (like a lot of body functions) which is part of the midbrain. This ",
"wiki article",
" describes the effects of cortisol creation which can negatively affect... | [
"One of the important building blocks of collagen is Ascorbic acid, aka vitamin C.",
"Humans and some other primates, have lost the ability to create our own ascorbic acid internally due to a mutation so we must ingest it.",
"We know that we die from the lack of it (scurvy), but preventing scurvy is simply the ... |
[
"what am I considered? alpha, beta or something else"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScience",
"For more information regarding this and similar issues, please see our ",
"guidelines.",
"If you disagree with this decision, please send a ",
"message to the moderators."
] | [
"We chose not to adresse personal questions. If you want a personal psychological evaluation you need to talk to a qualified professional. "
] | [
"We chose not to adresse personal questions. If you want a personal psychological evaluation you need to talk to a qualified professional. "
] |
[
"What's the biggest obstacle keeping us developing warp drive technology?"
] | [
false
] | I've heard warp drive kinda-sorta possible in the fact that it doesn't break any of Einstein's theories like FTL travel does. So why haven't I heard about anyone working to develop it? What difficulties are keeping us from moving forward? | [
"Whether or not it violates some physical law is still an argument in physics.",
"To be clear, what a warp bubble is is a chunk of flat spacetime. Just in front of the bubble is a region of contracting spacetime, while just behind the bubble is a region of expanding spacetime. A spacecraft could sit in the middle... | [
"I believe it's much worse.",
"Popsci tries to sell this as:",
"warp drives need ",
" that ",
" and maybe ",
"but this is incorrect. It's better stated, in my opinion, as",
"Warp drives need ",
". Warp drives need the stress energy tensor of something to be ",
". In fact, anything really freaky - CT... | [
"Also, the Alcubierre warp drive requires negative mass to work* and nobody knows yet if negative mass can exist.",
"*It was announced some time ago that improvements in the design had greatly reduced the amount of negative mass required, but it's still necessary. On the other hand, the ",
"White–Juday warp-fie... |
[
"why don't we keep our mother's immunity?"
] | [
false
] | newborn babies are protected by antibodies passed on from their mothers for a short time after birth. why doesn't this immunity persist? | [
"These antibodies are proteins with a limited half-life.",
"If the mother were able to pass some memory B-cells, they would last indefinitely and keep producing antibodies."
] | [
"First, what capy_capybara said is partially true. If you are constantly exposed to foreign antigens during the first year of life, your chances of developing tolerance are 100x. Nonetheless, your mother's lymphocytes and antiboides could attack your tissues (similar to Graft-vs-host disease or Rh incompatibility).... | [
"so why doesn't this happen? or maybe to put it another way, if memory b-cells were extracted from the mother and passed on to the child, would this produce immunity or is there some reason this wouldn't work?"
] |
[
"Fact or Myth: An ungloved hand can be dipped in liquid nitrogen without being damaged."
] | [
false
] | [deleted] | [
"That is absolutely true. That phenomenon, known as the ",
"Leidenfrost Effect",
" is the same reason that water appears to 'dance' on a hot skillet. But be careful, you need to be fast, or else the liquid nitrogen will eventually contact your skin. And Cryo burns are not fun. You can also dip a ",
" finger i... | [
"Just DON'T drink it!"
] | [
"To be doubly safe, cover your wet hand in molten lead before dipping in liquid nitrogen."
] |
[
"Just how strong is 3D printing?"
] | [
false
] | I read an article on the front page about how scientists are developing new materials to 3d print in order to better build electronic devices. I was thinking about the implications of this and I'm now thinking about how long it will take to improve the technology enough to build architectural structures out of this mat... | [
"3D printing isn't necessarily advantageous for something like a bridge. It's better at limited-production runs and prototyping. For a bridge, there are well-established construction methods, and costs are pretty well-defined for each. Printing a bridge would require printing many small parts, and nothing would ... | [
"Most 3D printers use polymers that are deposited in layers. The bond between those layers tend to be pretty weak structurally speaking. And polymers aren't the strongest materials to begin with. However with powdered metal process improving you can print using a metal powder and resin solution that can be sintered... | [
"Yes, you would be correct, my bad."
] |
[
"Is there a way to demonstrate that the speed of light is finite using household objects?"
] | [
false
] | Given the high tech equipment now available, such as DSLR cameras, laser pens etc, is there a simple experiment I can do at home to measure the speed of light? It would be a great teaching demonstration. Thanks. | [
"I saw a demo once with an oscilloscope, it's not exactly a household object but you could carry one into a classroom...",
"You could probably make a michelson interferometer out of household objects. Probably not what you're thinking of though...",
"You can measure the ",
" of light pretty easily with a las... | [
"The method discussed in this talk seems really cool, and extremely low tech, though I don't know how practical it would be for a teaching demonstration, since it might require a bit of prep (and some long unobstructed distances): ",
"http://ed.ted.com/lessons/how-simple-ideas-lead-to-scientific-discoveries"
] | [
"It would likely be fast enough, though if you cut slits in the CD to make the teeth, I would be concerned about safety, since structurally deficient CDs have been known to shatter. Perhaps a model airplane propeller could be repurposed somehow?"
] |
[
"A couple Big Bang questions"
] | [
false
] | Does the Big Bang theory describe only how the modern universe developed or does it actually postulate that the universe actually began from nothing? What is the leading model for pre-expansion matter creation? I've done a bit of research on the quantum vacuum model described by Krauss, but I've heard that Hawking pur... | [
"The Big Bang theory posits the conditions that existed a fraction of a second ",
" the universe began - not ",
" it began, or what came before it. ",
"As an aside, I see a lot of people referring to it as an explosion; this is a misnomer. The big bang was a universal expansion of spacetime. That is to say, "... | [
"This",
" is a good start to give you an idea of the different epochs that cosmologists think of.",
"There are a ton of proposals for pre-inflation cosmology (basically how to get inflation in the first place from various models). I think by expansion you mean inflation (when the universe rapidly accelerates t... | [
"There are a number of things that could be called Big Bang models. Most of the time, people are talking about inflation, (p)reheating, baryogenesis/leptogenesis, and then regular stuff like big bang nucleosynthesis (BBN).",
"None of these things actually adress \"how the universe began\". We've got more tenable ... |
[
"Does the visual cortex get 're-purposed' in blind people?"
] | [
false
] | null | [
"According to ",
"this study,",
" yes. They put stereo headphones on 12 sighted people and 12 blind people and had them point to where they thought the sound was, all the while under an MRI. In the blind the visual cortex showed more activity than it it did in the sighted. They did the same experiment, but i... | [
"Unless they did the same experiment on the same people before they went blind it's impossible to tell with certainty. But it's generally accepted that when someone is blind their other senses \"heighten\" or get better."
] | [
"Does it actually lead to notable improvement?"
] |
[
"Can anyone explain the effect on the motor when I stop a fan with my hand?"
] | [
false
] | I tried this question on and didn't get a very satisfactory answer, nor do I know how to cross post so I'm giving it another shot over here. When I stop a fan from spinning with my hand what effect does that have on it's motor, if any? My thoughts are that the energy going into the motor causes it turn with a certain a... | [
"An AC motor is nothing but a set of rotating electromagnets. While it's rotating, the changing electromagnetic field (EMF) keeps the complex resistance high, so that current flow is limited by the rotation speed designed into the motor for the given voltage (free speed).",
"As stated above, as you increase load... | [
"The motor winding's will heat up until they burn out because there is no where for that energy to go."
] | [
"It's not a simple transformation. It's Ohm's law. Generating an EMF field using a coil winding causes resistance when you use AC current.",
"The motor doesn't decide to draw more current. It draws current in response to the resistance of the coils. Heavier loads put on more resistance, requiring more resista... |
[
"Why are penises darker than the rest of the body?"
] | [
true
] | null | [
"Pheomelanin",
" is a pigment that produces a pink/red hue to the skin, and is found in higher quantities in the tissue of the penis than in other skin areas."
] | [
"It is probably because penile skin has a higher amount of a hormone named dihydrotestosterone (DHT) that is necessary for normal development of the gonads and normal erectile functioning. DHT is a derivative of testosterone when it's converted by an enzyme called 5-alpha reductase. "
] | [
"Why would it be on the skin of the penis and not somewhere else? "
] |
[
"Why do bacteria evolve and express a receptor for bacteriophages that would potentially compromise their survival? Are the receptors specific or do they just happen to be recognized by the phages?"
] | [
false
] | I'm taking a microbiology course and this baffled me. My professor didn't quite make it clear for me. Sources from where I could learn more about this would be much appreciated. | [
"It's the phage that recognizes an already existing protein in the bacteria as their receptor, not the other way around.",
"For example, the ",
"Phage Lambda",
" binds to an outer membrane protein in ",
" involved in Maltose uptake."
] | [
"Though I'm sure it is the former.",
"Really? I'm sure it's mostly the latter. Viruses evolve crazy fast (much faster than bacteria) and kill bacteria a lot more than they promote diversity."
] | [
"Though I'm sure it is the former.",
"Really? I'm sure it's mostly the latter. Viruses evolve crazy fast (much faster than bacteria) and kill bacteria a lot more than they promote diversity."
] |
[
"Could someone help me identify this tool?"
] | [
false
] | I am a high school science teacher. I found this tool while cleaning out the lab room. The top cone part is made of copper and is engraved with the text "made in west Germany". The silver blade part is not sharp, and swivels in and out of a groove on the copper cone. Help me identify this tool, Reddit! | [
"We have one of these in my lab. It's for making a sharp end to a piece of tubing. Like ",
"this",
", but smaller and smoother.",
"You insert the cone into the end of the tube, pull the blade closer and spin and the blade will shave off parts of the tube to give you a bevelled end. ",
"I can't find an examp... | [
"Okay, I've got an update. That tool is a sharpener for ",
"cork borers",
".",
"The borers are tubes used to cut cylindrical holes through rubber or cork stoppers, this tool keeps the borers sharp. The cone is so that the sharpener works on borers of multiple diameters.",
"This one looks like yours",
". "... | [
"Oh wow that would explain the cork borers I just found in the same drawer. I really appreciate all of the help. Now I am going to bore some cork with the kids next week!"
] |
[
"Could you make Helium-3 with Uranium-235 fission?"
] | [
false
] | Note: I am not sure if this should go under the Physics or Chemistry flair, so feel free to correct me. Fission using Uranium produces loose neutrons which speed away fast enough to embed themselves into other Uranium atoms, starting the reaction again. In theory, could this process be used with He-2 to make He-3? Say... | [
"Fission using Uranium produces loose neutrons which speed away fast enough to embed themselves into other Uranium atoms, starting the reaction again. In theory, could this process be used with He-2 to make He-3?",
"Helium-2 is unbound, so it decays on a timescale of 10",
" seconds. So no chance we're able to u... | [
"There is a helium-2 resonance, it's just not a bound state."
] | [
"I agree with the statement that \"There is no ",
"He which can be put into a reactor\", but I do not agree with the statement \"There is no ",
"He\"."
] |
[
"[X-post from Astronomy] Night sky sighting that I cannot identify - Astronomers, please help!"
] | [
false
] | . I was biking home from a festival, heading east, in Groningen, the Netherlands. At approximately 00:05 today on 28-8-2011, I looked up and noticed a bright reddish blob in the sky, at about 45 degrees from the horizon. At first I thought it was a hot-air balloon or chinese lantern, so I pulled off onto the sidewalk t... | [
"I think that the festival part of the story makes the chinese lantern theory highly plausible.",
"Depending on wind and atmospheric conditions they can appear quite unlike how you'd expect them to.",
"I had a similar experience a little while back: ",
"http://lookupandwonder.com/M51-And-UFOs"
] | [
"OK possible explanation.... it might have been a bird. ",
"I know, sounds ridiculous, but let me finish :-) First off, the biggest problem is that you do not know the distance of the object. It could be a lot closer by than we think, and than our brains interpret high-speed motion. This is the problem with most... | [
"Amateur astronomer here. Satellites just reflect the sun's light, so they wont shine reddish light at you. Iridium flares generally last of the order of a second or two. Meteors are far faster than any satellite (up to 10x faster notwithstanding any effects of perspective, and certainly ",
"no slower",
") and ... |
[
"Does the Earth’s revolution around the Sun depend on frame of reference?"
] | [
false
] | If motion is relative, why do we say that the Earth revolves around the Sun? Doesn’t it depend on whether your frame of reference is the Sun or the Earth? | [
"Motion is relative but acceleration is not. The heliocentric frame of reference is an inertial (ideally) reference frame where Newton's laws of motion hold. Changing to a geocentric view makes your reference frame non-inertial and introduces fictitious forces that other non-inertial frames will not agree upon.",
... | [
"Yeah but then you have to deal with curved spacetime. GR in most cases is like using a sledgehammer to hang a picture frame, you'll create more problems than you solve."
] | [
"But from a GR perspective, the earth just follows a geodesic around the sun, with no forces involved."
] |
[
"Why does the western part of North America have so many named, smaller deserts, despite seemingly all being next to each other? Why don't we name it as one single desert like we do with the Sahara?"
] | [
false
] | Reading through the on deserts in NA, I noticed that there's no single name for the desert on the western half of the continent, but it's seemingly broken up into smaller parts. Why is this? I suspect that part of it may be that, since it's oriented by longitude, the desert in British Columbia is different from Baja Ca... | [
"They are broken up largely through a mixture of geography (i.e. portions of deserts separated by mountain ranges), history (i.e. native peoples / settlers established distinct names / extents for a variety of reasons), and ecoregions (i.e. different flora and fauna that characterize these regions). ",
"This is n... | [
"also sahara on its own just means desert in arabic so the name is meaningless without the qualifying sub-names you mention. "
] | [
"They are largely different geological and ecological systems. I'm from Yucca Valley California originally, which is in the southern edge of the Mojave Desert. Mojave means \"high desert\" and it is very high altitude. Just down the hill (5 miles or so) is the Sonoma Desert which is completely different in what pla... |
[
"What is the best way to determine if an exoplanet is suitable to sustain human life?"
] | [
false
] | Just say in some near future we send out a bunch of probes in various directions to try and find a suitable planet for permanent colonisation down the track. What is the most effective test that can be performed in order to determine with 100% confidence that a planet is suitable for us to live on? Bonus question: how ... | [
"It's an interesting question you ask... ",
"But... there will NEVER be a 100% confidence-probability that an alien planet will be biologically-perfectly suitable for humans (as we exist today), unfortunately! ",
"When it comes to real life, in the real world, you can forget about the idea of \"100% guaranteed\... | [
"Part of the problem is we have a sample size of 1. Basically impossible to draw hard conclusions from. ",
"One key metric I've seen talked about is the presence of free oxygen. Oxygen is very reactive, if it is present in large quantities in molecular form it seems reasonable to infer that a process like life is... | [
"Yes that's completely right. ",
"There could be other things about Earth that turn out to be important, like the axial tilt, magnetic field, presence of the moon, and so on. A lot of potential Earths seem to be tidally locked - that also seems like a big variable that would have a huge affect on the prospects fo... |
[
"Is it possible to create a paint that corresponds to ultraviolet frequencies? Or, more generally, any portion of the light spectrum outside of visible light?"
] | [
false
] | Nothing is particularly 'special' about visible light objectively; we distinguish it from the rest of the spectrum only because it corresponds to the frequencies we can perceive. So what about the rest of the spectrum? Is it possible to invent an 'invisible paint' that will be the 'color' of non-visible light frequenci... | [
"'Invisible' paint has already been invented. ",
"Blacklight paint"
] | [
"I take it you have never been to a museum (or even Chuck E Cheese) where they stamp your hand with UV paint upon paying so that they can check later that you paid but you don't have an ugly visible stamp on your hand for the next two days."
] | [
"The reason paint (or just about anything) is of a specific color, is not due to the light it gives off, but rather due to the colors it reflects or absorbs. Wavelengths that are not absorbed and are reflected are then perceived as colors.",
"As you've guessed, there are many types of molecules that absorb, or do... |
[
"Why is boron trifluoride toxic?"
] | [
false
] | null | [
"BF3 is a fairly strong Lewis acid which can be dangerous, but where it gets really bad is that upon exposure to water it generates very dangerous hydrofluoric acid.",
"While not a strong acid, it is very good at penetrating tissues due to its small size and the fact that it doesnt readily dissociate. Once inside... | [
"The answer to the hypothetical is no.",
"BF3 is worse when it is exposed to water, but it is still an aggressive Lewis acid. It will go hunting for electrons and if it can't get the from water it will get them from somewhere else.",
"Biological systems are very tightly maintained in specific conditions, throwi... | [
"Actually in the absence of water the B-F bonds are quite stable and strong.",
"The Lewis acidity comes from the vacant P orbital on the Boron; it is very low in energy so readily accepts electron pairs."
] |
[
"Magnets bending light? This youtube video shows just that, however I can't make any sense of it with my understanding of EM theory. Can somebody explain to me what is going on here? https://m.youtube.com/watch?v=L9pqAeUtUV8"
] | [
false
] | null | [
"Quack"
] | [
"Thank you, thats what my instincts are telling me too. However, I still don't understand what is going on. So do you have an reasoning behind that claim, or a theory about what we are seeing, please let me know. "
] | [
"Random images with a guy rambling?"
] |
[
"Why do the fundamental forces dominate at different length scales?"
] | [
false
] | Do we know why, or is it simply accepting the observations? | [
"There is a problem with answering this question ",
"the problem is well explained by Mr. Feynman",
".",
"So what exactly do you want to know? Eventually everything comes down to \"simply accepting the observations\" but there are lots of levels of explanation between knowing nothing about it and there. So, a... | [
"\"Why\" versus \"how\" is either semantics or just fastidious avoidance of your question. I was once involved in a project looking at gravity on submillimeter length scales. Simply put, looking for variation from the 1/r",
" dependence. The theory was that gravity might be wound up more in the higher dimensional... | [
"There are two solid reasons why this is the case, but as it turns out they raise a new problem, why are the forces different strengths?",
"See, ideally all forces would be like gravity and electromagnetism, and they would have infinite range. The strong and weak forces however are very short range, and for two c... |
[
"Use of bra-ket notation in quantum mechanics?"
] | [
false
] | So, I've been reading up on some Wikipedia articles on bra-ket notation, spin, etc. And I noticed that the difference between bra-ket notation and normal vectors is that bras <A| are complex conjugates with kets |B>. I can understand a usefulness of complex conjugates with respect to pure mathematics, but what are so... | [
"There are cases where ",
" is convenient (optics, waves, oscillations, complex impedance), but in quantum mechanics, the use of ",
" and complex numbers is intrinsic to the equations. ",
"The fundamental way to see this is that the way the uncertainty principle is encoded mathematically intrinsically involve... | [
"Waves. It's much easier to work with oscillations written in the form y = e",
" than it is to work with them in the form of y = cos(x). And in quantum mechanics, waves and wave functions are everything."
] | [
"Physical observables might be restricted to real values, but we often need complex numbers to express the state of the of a system. The bras and kets are used to represent state vectors. These are generally written in the form of a set of numbers that represent the decomposition of the vector with respect to a cer... |
[
"Is our solar system (sun) orbiting the milky way black hole?"
] | [
false
] | null | [
"Not really!",
"We are orbiting the supermassive black hole in the centre of the galaxy only in the sense that we are orbiting around the centre of the galaxy and there is a supermassive black hole there. However, if you removed that supermassive black hole, we would still orbit around the centre of the galaxy!",... | [
"Mostly yeah - without dark matter, a big chunk of the galaxy would be above escape velocity"
] | [
"That's fascinating. I always thought the SBH was the driver (of the rotation) of galaxies, and dark matter was something like the invisible glue that connected everything to the SBH. ",
"Does this mean that dark matter is the only reason galaxies stay together at all? "
] |
[
"If the human eye was a camera, what would its resolution be? (in pixels)"
] | [
false
] | null | [
"For those who don't feel like reading through all that, around 576 megapixels.",
"Obviously that number can change depending on many factors, but if you just want a ballpark estimate, there you go."
] | [
"For those who don't feel like reading through all that, around 576 megapixels.",
"Obviously that number can change depending on many factors, but if you just want a ballpark estimate, there you go."
] | [
"So my eyes are roughly 30 times better than cameras, and yet I still need glasses to make out letters that are 3 feet from my face? Thanks mother nature."
] |
[
"Are there any studies on otherwise healthy adults purposely using ritalin/adderall as a study/work/programming aid?"
] | [
false
] | Programmers are perpetually trying to chase a mental state sometimes referred to as "The Flow"/"Hack zone"/"In the zone" where you're simultaneously hyper-alert but also calm and able to juggle more thoughts in your head without confusion. As a software developer I regularly self-medicate with caffeine and sometimes al... | [
"Hi Gilgoomesh,",
"Looked into your question and it seems there are a few studies, all smale scale though. ",
"http://www.ncbi.nlm.nih.gov/pubmed/21859174",
" and ",
"http://www.ncbi.nlm.nih.gov/pubmed/21368261",
".",
"From personal experience I can say, yes there is a benefit. You will be more focused ... | [
"To add on to reasons why it would be a bad idea to use these drugs, there is actually an adderall shortage right now because so many people are using it recreationally, such that some people with actual disorders who need the medication can't get it. "
] | [
"Ritalin and Adderall are two different drugs that can have very different effects on people. Adderall was pulled from the market in Canada because of concerns. I recall seeing news stories about how it made some people have serious lapses in sanity. Ritalin is different. They both can give you the ability to hype... |
[
"In terms of getting the most nutrition out of food; how efficient is the human digestive system in comparison to other creatures?"
] | [
false
] | [deleted] | [
"Well you were each eating different food, so that makes cross animal ranking somewhat dubious... Dog, human, and cow for example each have really different efficiencies for different foods because they by definition evolved to fill different niches. Dog cannot get much nutrition out of grass, but cow has a specia... | [
"There is an interesting discussion of the different types of digestion ",
"here",
"."
] | [
"Well ruminants have very modified foreguts for the digestion of cellulose and hemicellulose, where they keep all sorts of symbiotic critters around that aid in the digestion of that stuff.",
"Humans can't digest cellulose to any major degree. Cows aren't carnivores though, and even carb-rich meals will apparent... |
[
"How does an electric motor work, and how does it differ from a homopolar motor?"
] | [
false
] | Which one is more efficient, provides more torque and how is it used? Sorry if this is a bit to general, if you could even just link an article that'd be helpful! | [
"A homopolar motor is an electric motor. There are other kinds, of course. The basic principle relies on the \"right hand rule\" which means this: hold your right hand out like you're giving a thumbs-up. If there were a current running out of your thumb, there would be a magnetic field coming out of your fingers. T... | [
"Homopolar motors have a huge problem: they are essentially a \"one-turn coil.\" They require short, enormously thick connecting wires, and operate at millivolts and enormous amperage. They require huge sliding contacts, preferably using liquid metal.",
"To fix the problem, just use a many-turns coil. This let... | [
"An excellent explanation. You're a great help!"
] |
[
"Are Magnetospheric Eternally Collapsing Objects a plausible alternative to black holes? Why or why not?"
] | [
false
] | null | [
"What is an eternally collapsing object?"
] | [
"http://www.scitopics.com/Eternally_Collapsing_Object.html"
] | [
"So, something destined to be a black hole but so perfectly balanced that it collapses at an imperceptible rate?",
"Color me dubious.",
"These things all have tipping points. You are on one side or the other. Not in some near-perfect equilibrium.",
"And by \"near-perfect\" I mean it. There is no room for e... |
[
"AskScience AMA Series: I am Dr. Laura Kloepper, a biologist who studies the emergence and echolocation dynamics of large bat cave colonies. This summer I am traveling and camping with two female students as we record bats across the Southwest. Ask Me Anything!"
] | [
false
] | Hi Reddit! I am Dr. Laura Kloepper, an Assistant Professor of Biology at Saint Mary's College in Notre Dame, Indiana. My research involves using audio, video, and thermal imagery to understand the emergence, flight, and echolocation dynamics of large (1 million +) colonies of Mexican Free-tailed bats. These bats leave ... | [
"Out of curiosity, why was it necessary to mention that the two students assisting you were female?"
] | [
"How do the bats avoid crosstalk? Do they all echo locate at different frequencies, or is it highly directional? Or do they rely on some kind of \"near field\" communication with a couple of key bats doing the ranging for the group?"
] | [
"This is exactly what I am studying! So far most of our knowledge is from bats in pairs or small groups in the laboratories. Bats in general make very short, directional echolocation sequences, but there is a lot of overlap in call frequencies. When bats fly together, data show that they will slightly adjust their ... |
[
"What do gravitational waves propegate through? What is the medum?"
] | [
false
] | null | [
"There is no traditional medium. Much like electromagnetic waves, gravitational waves propagate as oscillations on a field. The tricky part is that while EM waves propagate on an electromagnetic field which fills all space, gravitational waves propagate on space itself.",
"Whether you wish to call this \"aether\"... | [
"That's true but the issue I'm trying to raise is in your final phrase there:",
"The spacetime manifold is important to how the electromagnetic field behaves.",
"The metric is not the manifold, it is a field on the manifold very much like any other. It just happens to tell us how to measure distances with physi... | [
"The tricky part is that while EM waves propagate on an electromagnetic field which fills all space, gravitational waves propagate on space itself.",
"I'm not sure what distinction you are trying to draw here. Gravitational waves are perturbations of the metric just as EM waves are perturbations of the EM field. ... |
[
"How bright does the sun appear from space, in orbit around the earth?"
] | [
false
] | I assume the atmosphere scatters the light a lot - does that mean that the sun looks like a really bright point source? | [
"It depends totally on atmospheric conditions, and where on the Earth you are, and you elevation, and so on.",
"At the equator, during clear weather, if the sun is at a 45 degree angle, only about 70% of its photons are reaching your eye. So it would, conversely, be about 40% brighter if you were in space.",
"E... | [
"How is that calculated?"
] | [
"There's a fairly simple set of equations to use which tell you what percentage of photons pass through the atmosphere at a given angle at sea level. Things get more complicated if you take in higher/lower STP, or elevation, or smoggy/cloudy conditions, and so on (which is why I kept all the assumptions null).",
... |
[
"What is live culture yogurt and how does it aid in digestion?"
] | [
false
] | null | [
"Live culture means that when it was packaged there were live bacteria present within the yogurt. In fact, the reason it's yogurt in the first place is due to bacteria. After mixing together all the ingredients in yogurt (milk, sugar, etc.) it's boiled to kill off all the undesirable bacteria, then specific culture... | [
"Loosely, this is correct. Consuming ",
"probiotic",
" cultures stabilizes gut microbiotia and provides various beneficial effects to the consumer. In the case of live culture yogurt, the ",
"specific type of bacterium",
" used in production is the probiotic culture that provides the beneficial effects. ... | [
"Read the container! Usually its strains L. acidophilus.",
"It helps because the bacteria produce enzymes that aide in breaking various proteins and fats."
] |
[
"Is there an 'opposite' of ADHD?"
] | [
false
] | null | [
"disorders of the brain do not generally fall along a neat linear continuum the way that some disorders of the rest of the body (eg endocrine hypo or hyper activity) do. this is because disorders of behavior are incredibly complex.",
"there is no such thing as the opposite of ADHD or schizophrenia or personality ... | [
"He's saying that the actual differences in the brain are so complex that there is almost no chance of finding exact opposites. Say insomnia and narcolepsy, they seem to be opposites but how they're affecting the brain, and which parts of the brain are affected are not related in any way."
] | [
"He's saying that the actual differences in the brain are so complex that there is almost no chance of finding exact opposites. Say insomnia and narcolepsy, they seem to be opposites but how they're affecting the brain, and which parts of the brain are affected are not related in any way."
] |
[
"Today I found what appears to a be a plant that repaired a broken limb with as smaller support limb. What is going on with this? (Pics inside)"
] | [
false
] | So I am calling it a buttress, but I don't really know what this phenomenon is called. I have been unsuccessful in googleing any information on the matter. Please excuse my fuzzy phone pics. PS: I posted the same gallery in to see if they could identify the plant itself, in case that helps. EDIT: Thanks for all of th... | [
"I realize this may not be of any help for this particular post, however, when trying to identify a plant species you need a picture or it's full form, an upper leaf, under leaf, the bud, branching pattern, and any fruit or inflorescence , also knowing the location and whether it is a high and dry site or low and w... | [
"Hello, plant guy here. what you are seeing is common in the plant world. it is not a respons to the broken limb, its a respons to growing toward the ground and hitting it then looking like it was ment to be that way. "
] | [
"I have a very large beech tree growing beside my house. It has a similar thing, but with massive branches, as big around as some smaller, younger trees. I always thought it was an interesting formation. If anyone's interested I could take a few pictures of it.",
"Edit: ",
"Took some pictures",
", please excu... |
[
"How can I preserve a dying family member's genetic material?"
] | [
false
] | [deleted] | [
"Freeze a tissue sample at -80C."
] | [
"Human hair is a pretty good source of DNA (",
"source",
"). Moreover, it looks like hair samples degrade the least when they are frozen at at least -20C in a non-freeze/thaw freezer within 6 months of obtaining the sample (",
"source",
")."
] | [
"It doesn't matter if the cells die if you just want to preserve the DNA."
] |
[
"Do men go through any physiological changes when their partner is pregnant?"
] | [
false
] | When a woman is pregnant she goes through a lot of hormonal and physical changes as she come to term. Do men typically experience any hormonal or physical changes as their partner progressing in the pregnancy? | [
"Try ",
"this",
" one. Expectant fathers have elevated prolactin & cortisol (before the baby is born; compared to levels from earlier in pregnancy).",
"See also ",
"this review",
" on ",
"Couvade syndrome",
", the psychological & physiological changes that occur in some men when their partners are pre... | [
"Yes. New fathers have increased levels of prolactin (same with mothers). Artificially increasing prolactin levels leads to increased paternal care in some species. ",
"Source.",
"Edit: I should say that this article only has data on prolactin levels AFTER the birth of a child, not when the mother is pregnan... | [
"Awesome. Thanks."
] |
[
"Why is Dark Matter called 'matter'?"
] | [
false
] | Aside from the fact that the word 'dark' is a placeholder term. As far as I understand we have only measured unexplained gravitational effects. Wouldn't it be more accurate to call it 'dark gravity'? Is matter literally the only thing we know of that could produce such effects? | [
"We really do believe it is most likely an actual form of matter. It is the simplest explanation, and doesn't require arbitrarily changing the fundamental laws of physics to fit our observations.",
"And that's really the only alternative to dark matter - just inventing new laws for gravity. This is tricky, becaus... | [
"Great explanation. If you don’t mind, maybe we can add it to the FAQ?"
] | [
"The dark matter component should be 5-10x more massive than the total of gas & stars, so the gas & stars do make a difference, but not enough to stop the dark matter in its tracks. What really happens is you get a \"halo\" (a blob) of dark matter, which captures gas inside it, that forms stars - it's the dark matt... |
[
"What's the difference between a sociopath and a psychopath?"
] | [
false
] | I know that there is a difference, but I'm unsure as to what the actual difference is. Can someone explain symptoms-wise, and possibly even psychologically what's different, please? | [
"If you read \"Without Concious\" by Hare (who is the guy who deemed the construct psychopathy), he essentially says that there is no difference between the two terms. He goes on to say though that a psychopath probably has more genetic roots to their behavior whereas a sociopath likely has more environmental roots... | [
"To clarify the distinction: the difference in nomenclature - and that's all it is, really - is mostly a reflection of the attitudes of the author. Whether someone calls someone a psychopath or a sociopath is mostly whether the author attributes the traits to a genetic predisposition or societal and institutional i... | [
"I have been unable for a number of years to find a source which provides a distinction between the two, although I have read works which essentially equated the two concepts. Do you have one you can cite?"
] |
[
"How can Greenland Sharks live up to 500 years and why can't humans live as long?"
] | [
false
] | null | [
"https://oceanservice.noaa.gov/facts/greenland-shark.html#:~:text=But%20even%20at%20the%20lower,deep%2C%20cold%20waters%20it%20inhabits",
".",
"“The largest shark they found, a 5-meter female, was between 272 and 512 years old according to their estimates. Carbon dating can only provide estimates, not a definit... | [
"In addition to resilient hearts, Greenland sharks have an extremely low risk for cancer and infectious diseases. Their autoimmune system paired with their body’s high ammonia levels make their bodies unfriendly to viruses, bacteria, and diseases that affect most other animals."
] | [
"Thank you. This is a very clear and informative answer."
] |
[
"What is the latest and greatest theory of the origins of life on Earth?"
] | [
false
] | I have heard that the 'Primordial Soup' model most of us were taught in grade school is largely regarded as discredited. What is the current thinking? | [
"Some version of the primordial soup is right; there were lots of free organic molecules floating around, some how they got into the right configuration to start self replicattion. Most of the current work has been focused on what order the core aspects of life arose in and where.",
"Key things you need for life ... | [
"We don't know. There are a lot of potential ideas and the current favorite seems to be archean volcanoes. We have yet to really see when life began (it goes back to 3.8 billion years ago). So we don't know in what time period it would have started and therefore don't know the conditions that were prevailing at the... | [
"Jack Szostak is investigating this in his lab.",
"Here's a paper"
] |
[
"Where do the dead bodies of the deep-sea creatures go?"
] | [
false
] | Human dead bodies that are usually dumped in the ocean, tends to float and usually gets found near the shores. So why haven't we found any of the dead bodies of the mysterious creatures that live in the deep sea, i.e. in areas where the sun light doesn't reach? Don't these dead fishes float? Or have they occasionally b... | [
"Many organisms sink after death. The deep sea ecosystem depends on these infrequent food sources. ",
"Abyssal Megafauna",
" are adapted to survive relatively long periods between opportunities.",
"Blue whales, for example, will float at the surface for a short period of time as the bloat and gasses build i... | [
"Because when they die, other creatures eat them. It's a long way to float from the deep sea to the beach."
] | [
"http://www.youtube.com/watch?v=rdI3eFrTGs8"
] |
[
"Best copy of \"On the Origins of Species\" to buy."
] | [
false
] | [deleted] | [
"It's one hell of a dry read, you can ",
"download it here",
" if you really want to read it. It's not really a book for the general public though. I've got a slightly damaged copy from the late 1800s which I got from ebay for under $10.",
"tl;dr: We can make new breeds by \"artificially selecting\" dogs, pig... | [
"Don't be surprised if the words/terms are archaic, and his arguments seem somewhat haphazardly organized. In the early days of such theories, people hadn't fully figured out the relations between all these new concepts, yet.",
"Also, don't be surprised if Darwin's understanding of natural selection is slightly ... | [
"Isn't there one that comes with a forward from kirk cameron that has a bunch of modifications? I would avoid that one unless you want to laugh."
] |
[
"What's the name of a phenomenon where we tend to notice some things much more while we are constantly thinking about them?"
] | [
false
] | For example, one day you just start noticing birds, and end up noticing much more than usual and you could swear there weren't so many birds before, but in reality there was the same number of birds every day, only your mind was occupied with searching for them. I hope I am being clear enough. Is there a term for this ... | [
"Availability heuristic",
" or ",
"priming"
] | [
"Frequency illusion is also popularly known as Bader-Meinhof phenomenon."
] | [
"Frequency illusion is also popularly known as Bader-Meinhof phenomenon."
] |
[
"Is there an opposite of albino? Can a white person be born black?"
] | [
false
] | [deleted] | [
"The disease exists, but I haven't found evidence of it in humans. Its called Melanism.",
"EDIT: Black Panthers are an example of this"
] | [
"As DarkGrenchler rightly pointed out, Melanism is your culprit, but I thought I would cover the 'evidence in humans' part.",
"Dr. David Henley points out",
" that the closest presentation in humans is ",
"Peutz-Jhegers Syndrome",
".",
"It is a condition characterised by colonic polyps and patches of hype... | [
"Thank you for adding this, because I was a tiny bit confused. Seriously."
] |
[
"If Scientists want to clone a Mammoth using Mammoth DNA, why don't Scientists try to clone early Human life using DNA found."
] | [
false
] | I think it would be really cool to clone a neanderthal and show him the new world! | [
"I'm not sure if the genetic material preserved in such cases is of adequate quality to attempt cloning.",
"Even if there were, contemplating the political/ethical/religious backlash would be make any public-facing researcher decide against attempting such a thing. ",
"However, given a permissive political/eth... | [
"They only have about 60% of the Neanderthal genome at present as far as I'm aware. And this is from only 3 individuals. ",
"http://www.time.com/time/health/article/0,8599,1987568,00.html",
"http://www.huffingtonpost.com/2012/03/20/neanderthal-eyes-brown-dna-study-genome_n_1367426.html",
"I do wonder if it wo... | [
"Does anyone know of any papers reviewing the cases of decently well-preserved hominid remains?"
] |
[
"Ask Anything Wednesday - Engineering, Mathematics, Computer Science"
] | [
false
] | Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical post? No question is too big or small for AAW. In this thread you can ask any science-related question! ... | [
"The sum of all integers is a divergent series, and because it's a divergent series, it doesn't sum to anything. In fact, with divergent series, you can often times make them \"sum\" to almost anything. Look at a slightly different version of your series:",
"1 - 2 + 3 - 4 + 5 - 6....",
"Note if you decide to pu... | [
"The sum of all integers is a divergent series, and because it's a divergent series, it doesn't sum to anything. In fact, with divergent series, you can often times make them \"sum\" to almost anything. Look at a slightly different version of your series:",
"1 - 2 + 3 - 4 + 5 - 6....",
"Note if you decide to pu... | [
"PEMDAS is a set of evaluation rules. They are a mnemonic of conventions which exist to eliminate ambiguity of notation:",
"It's perhaps worth noting that certain calculators ignore this by construction, and evaluate an input expression on each operator input: they cannot properly evaluate expressions like ",
"... |
[
"I just sat in my kitchen in silence for an hour and didn't notice the clock on the wall ticking until thirty seconds ago. How does the brain prioritize sound?"
] | [
false
] | null | [
"It's not so much prioritization, it's more that the auditory section of your brain underwent ",
"neural adaptation",
" to the stimuli (clock ticking) so that you no longer consciously registered it. ",
"This process occurs for much of the information taken in by your sensory system - for instance, you're pr... | [
"It is maddening to hear a clock ticking all the time - as novice hearing aid users can attest",
"When hearing deteriorates this adaptation to background sounds is lost. If you don't hear a sound then there's nothing for the brain to adapt to.",
"When people start using hearing aids, sounds like the ticking of ... | [
"Your brain doesn't have the power to process all of the information that is sent to it at any time. It has to pick and choose what to focus on and what to ignore. Inconsequential things, like the clock ticking or your clothes touching you, are ignored so more important things can be processed."
] |
[
"If I have a meal that is only 1 cup of olive oil (i.e. 100% lipid) ... how will my body synthesize it? Will excess be stored as fat, excreted in feces, or other? What parts of the digestive system will it strain?"
] | [
false
] | Of course it's not a healthy meal .. but lets ignore the aspect of lacking other nutrients for a moment. I'm interested to know what the body does if we consume more lipids than we need in a meal. | [
"1 cup of olive oil is about 237ml which is somewhere around 219.55g of olive oil. Give or take a little error most fats work out around 9cal per gram. So your cup of olive oil is about 1975.95cal. This is going to be around the entire per day calorie consumption for many folk.",
"So what is going to happen if yo... | [
"great detail - thank you.",
"now this begs two followup questions : ",
"(1) i often will have a big salad with maybe half a cup of oil (and some vinegar or lemon juice) as dressing (i'm italian, so it's ok, we love olive oil). will these extra ingredients, including the leafy greens, tomatoes, onions, cucumber... | [
"I'd guess that you are probably over estimating the amount of oil (maybe not). 2 tablespoons of oil on a side salad would make it noticeably greasy.",
"Nevertheless in either the steak or salad scenario the additional food will both slow down the rate of passage of the food and make the fat less concentrated. Yo... |
[
"I have a disgusting question about rotting bread."
] | [
false
] | [deleted] | [
"Maggots don't just appear when things get old and moldy...All you need is a fly to lay eggs in it. I once read that the time frame between eggs being laid and maggots hatching is only about a day. ",
"I would conclude that the bakery probably has a fly problem. Some flies laid eggs on your bread, and within a da... | [
"So do flies not normally lay eggs in bread? I've never seen a maggot in bread before, even old bread that is open to the air."
] | [
"I'm not sure where flies prefer to lay eggs, but I do know that fly larvae aren't exactly the most mobile creatures. Some how, eggs did end up in your bread."
] |
[
"How do today's computers know not to \"hyperprocess\" old apps and games made to run on a 200MHz processor, for example?"
] | [
false
] | I was rummaging through my shelf and found a copy of 102 Dalmatians, and old childhood memory. Made in 2000, for Windows 95/98 computers, needing only 32MB of RAM and a 233MHz processor and only 100MB of space to install, it's and very lightweight game for today's computers. I installed it on my desktop with its 2.9GHz... | [
"I'm not sure what they do use, actually - maybe someone with more experience in the area can answer that.",
"All simulation happens in terms of \"delta-time\" or the length of a single frame, typically measured in seconds as a floating point number, and there are two general approaches to it:",
"The operating ... | [
"They don't know not to \"hyperprocess\". It's a matter of how the game was programmed. If it uses the actual clock rate of the processor as its timer, it will not run properly on processors other than those in the range it was designed for. As you noticed, some older games are like this - it was such a problem ... | [
"Ironically enough, pressing the Turbo button actually ",
" your computer to the 4.77MHz clock rate of the original 8088.",
"Many processors now have something called \"Turbo Boost\" (Intel) or \"Turbo Core\" (AMD) which do what you'd think: speed up the processor. That's unrelated."
] |
[
"We can find Martian meteorites on Earth. But can we find Terrestrial meteorites on Mars ?"
] | [
false
] | null | [
"Yeah, there's no particular reason we shouldn't be able to, but finding meteorites is rather difficult, even on Mars where there's much less atmosphere to stop them. We just haven't explored the planet thoroughly enough with rovers to find any coming from Earth yet."
] | [
"They’re also pretty easy to find on earth. Most of the Mars meteorites found have been found in Antarctica. They fly along at low altitude over the ice and look for rocks. If they find a rock on top of the ice, chances are it’s extraterrestrial."
] | [
"In theory yes but they would be much rarer than Martian meterorites, since Earth is much more massive than Mars so has a higher escape velocity, we have a much thicker atmosphere so more energy is lost to drag and meteors are much less likely to reach the surface.",
"Tl;dr You basically need to hit the Earth wit... |
[
"What causes cankersores and how can you prevent/heal them quicker?"
] | [
false
] | [deleted] | [
"Also, avoid toothpastes with ",
"Sodium Lauryl Sulfate",
"."
] | [
"http://www.webmd.com/oral-health/guide/canker-sores"
] | [
"<grin> It was such an easy web search..."
] |
[
"If Jupiter is gas giant does it have a surface that you could theoretically stand on ?"
] | [
false
] | null | [
"This is a cool question with a (scientifically) cooler answer: We have no idea!",
"Nothing we have, no sensor or probe or anything, can grind through the chaos that is Jupiter's ever thickening layers.",
"These guys at NASA",
" are pretty smart though, and they say that at some point you're going to encounte... | [
"Fluid gasses? o.o"
] | [
"Fluid gasses? o.o"
] |
[
"In this pic of Mercury, what is the giant flat plain? This is the only picture of Mercury showing this plain and I cannot find any information on it."
] | [
false
] | null | [
"As others have mentioned, your map of Mercury was built by assembling lots of pictures taken by Mariner 10, and the \"flat plain\" is an area where data is missing. But the missing data problem is worse than it looks! Your map shows the ",
" side of Mercury. Here's a rectangular map that shows everything we k... | [
"Great explanation, thanks!",
"It's crazy to me that people understand orbital mechanics well enough to calculate the best trajectory for maximum surface coverage for stuff like this. ",
"Or the one that orbited that asteroid like 11 times before landing. Unrelated but this just is just incredible: ",
"https:... | [
"According to ",
"this site",
" there has only been one mission to mercury. It said only 45% of it has been mapped. I'm assuming that the blank is not a giant plaine, but the 5% of that side of the planet that was not mapped.",
"Edit: The source is outdated. There has been a more recent mission to mercury tha... |
[
"A friend described plastic particulate in the ocean as being just as dangerous for organisms living there as sharp broken glass lying around is for us. Is this a fair comparison?"
] | [
false
] | null | [
"You might have wondered this because it's already been researched."
] | [
"You might have wondered this because it's already been researched."
] | [
"And is there?"
] |
[
"How does the brain interpret the passage of time?"
] | [
false
] | For example, we are all capable of counting down (ie we have an internal stopwatch). What mechanism allows us to monitor time passage relatively accurately? | [
"That's of course not true. The ability to measure time across a broad range of scales is necessary for proper brain function. And by function, I mean to do things like walk, perceive, and plan actions and sequences of actions. We know this also from psychophysical experiments. Time estimation follows normal pschop... | [
"Humans rely on environmental factors to monitor the passage of time. The most primitive of which being the sun, and how our circadian rhythms relay back to our brain when a day has passed. If we were locked in a window-less room, we would be very inaccurate at telling the time. We could guess based on our own bo... | [
"I think this only partially answers the OP's question. How does the brain measure time exactly? Is there a neural structure that measures time passing like a pendulum clock? I understand the cerebellum is largely responsible for rhythm, but is there a subconscious effort at play as well?"
] |
[
"Do solid or porous objects with open pores actually deform under uniform hydrostatic pressure, such as under water?"
] | [
false
] | null | [
"Yes, in general they will, but not because the pores collapse. Provided that the surrounding fluid can enter the pores, the main compression is elastic compression of the solid itself, which should generally result in a self-similar shrinkage (provided the solid is a uniform material)."
] | [
"Note, however, that the decrease in volume is generally tiny because the bulk modulus of condensed matter is quite large. This may be what the question is getting at. The bulk modulus of a polymer is generally a few GPa; even if you move a solid cube of plastic to the bottom of the Mariana Trench, it'll compress b... | [
"Good point!"
] |
[
"Can extra organelles be added to cells?"
] | [
false
] | [deleted] | [
"Yes, it's not easy but scientist have done something like that in zebrafish:",
"Agapakis, Christina M., et al. \"Towards a synthetic chloroplast.\" PLoS One 6.4 (2011): e18877.",
"There is also a slug that can do something like that by stealing chloroplast from algae."
] | [
"Mitochondria and chloroplasts have their own DNA, so its a bit different from other organelles. The first cell that absorbed a mitochondrion or a chloroplast didn't have to reprogram their DNA as such initially, they would have just divided with the mitochondria dividing inside also. Its a pretty huge change thoug... | [
"Mitochondria and chloroplasts have their own DNA, so its a bit different from other organelles. The first cell that absorbed a mitochondrion or a chloroplast didn't have to reprogram their DNA as such initially, they would have just divided with the mitochondria dividing inside also. Its a pretty huge change thoug... |
[
"Do vaccines prevent or reduce the likelihood of mutations?"
] | [
false
] | null | [
"The part that is not flawed premises has been recently asked. Vaccines can and do entirely prevent replication, and there have been questions about the effect of vaccines on mutation (global prevention because of reducing the pool of variation)."
] | [
"Do you have a source on this? I'm completely out of the loop and would like to read up more about this."
] | [
"Multiple previous questions on ",
"r/askscience",
"."
] |
[
"What exactly is it about lack of sleep that creates or worsens undereye bags?"
] | [
false
] | null | [
"That location of skin is thinnest on the body. What you are seeing is happening to all of the skin but most visible due to the thinness.",
"Sleep is when many of the adrenal hormones (glucocorticoids, epinephrine) are replenished. Without sleep there is a lack of these hormones. These hormones also police blood ... | [
"Hormones control a ",
" of what keeps you in working order.",
"Here's an article about adrenal hormones and how they help control things like salt balance in your bloodstream.",
" Too little aldosterone -> too little salt in your blood -> less osmotic pressure hydrating your cells. The water just doesn't get... | [
"Why would sleep deprivation cause dehydration?",
"Assuming you keep drinking fluids, wouldn't you remain adequately hydrated?"
] |
[
"How do we recognize people when they are too far away to see distinct details?"
] | [
false
] | While driving today I noticed someone a fair distance away and immediately thought it was a coworker of mine, and I was right. I could't see her face, and there isn't anything unusual about her, so how/why did I think it was her? What are we recognizing when we can't see faces or other obvious identifiers, but still kn... | [
"We use a whole host of cues. One surprisingly effective cue is (biological) motion - how we walk (",
"Troje et al, 2005",
").",
"For example, have a go playing with the ",
"biomotionlab app",
" to see what information you can extract from basic modes of articulation."
] | [
"Ooo, you gave me a source! Thank you!",
"If I'm understanding it right, although motion is a effective means of identification, we aren't sure why, or what exactly it is we are picking up on. Do you know of some other sources that explain a bit more about identifying through motion?",
"What are some of the oth... | [
"It does, thank you. "
] |
[
"How do plants know when to start blooming?"
] | [
false
] | Do plant hormones have something to do with it? Is it triggered by temperature? | [
"It has to do with the number of hours of light the plant gets each day. ",
"Here's an example: Indoor marijuana growers all know to initially grow their plants with 18 to 24 hours of light each day when they are young. When they want the plants to flower, they cut the light down to only 12 hours per day. That's ... | [
"According to the ",
"florigen",
" hypothesis, you would have to actually graft a leaf on to another plant to get it to flower and this may not work in all plants. ",
"Grafting is actually how the florigen hypothesis was discovered. The leaf would have to be producing a particular protein called FLOWERING LOC... | [
"Since we're at it, can you explain how autos work? AFAIK they trigger flowering stage on their own."
] |
[
"AskScience AMA Series: I'm Jon Schwantes from Pacific Northwest National Laboratory, and my team is working to uncover the origin of uranium \"Heisenberg\" cubes that resulted from Nazi Germany's failed nuclear program. Ask me anything!"
] | [
false
] | Hi Reddit, this is Jon Schwantes from PNNL. My team and I are working to uncover one of history's great mysteries. During WWII, the United States and Nazi Germany were competing to develop nuclear technology. The Allies thwarted Germany's program and confiscated 2 inch-by-2 inch uranium cubes that were at the center of... | [
"Did Heisenberg willingly obstruct/prevent the progress to an atomic bomb or was he genuinely trying to create one for the Nazis? \nIs there any scenario where they could have succeeded or was this impossible as they were unable to match the resources to match the manhatten project? \nThanks"
] | [
"Since they have answered, I'll just chime in as a historian of nuclear weapons. The answer to the Heisenberg question, so far as serious historians can tell, is \"neither.\" Heisenberg was not trying to obstruct progress, but he was also not trying to create an atomic bomb for the Germans. The German atomic progra... | [
"1st Question: I've read several times about the famous \"demon core\" accidents. Cubes seem like a very easily stackable form factor, are there concerns and/or regulations and/or common handling practices for the shapes fissile materials are produced in, to reduce the likelihood of a critical amount being stacked ... |
[
"How do light waves activate photosynthesis?"
] | [
false
] | null | [
"Actually, it was only very recently that the mechanism of converting light into energy via photosynthesis was discovered.",
"It's actually an incredibly complicated process that leverages some very interesting quantum properties of light and substrate interactions. ",
"Obviously, the structure, at the macro a... | [
"Very exhaustive answer, but I think you've used \"cell\" instead of \"molecule\" in a couple of places toward the end? Chromophores aren't a type of photosynthetic cell, but rather part of the light-receiving molecule; the exciton doesn't travel from cell to cell, but within or between molecules."
] | [
"What I meant by cell wasn't in a biological sense, but in a more mechanical sense; as in sort of a quantum bucket where photons drop into. "
] |
[
"Why do we need dark matter and energy to explain accelerated expansion of the observable Universe?"
] | [
false
] | null | [
"There's a few things wrong with the assumptions behind the question. The universe is not expanding from a literal point in space, and dark matter is not part of any explanation of the accelerated expansion we observe, except maybe as a counter force to the expansion since it's exerting a pull. ",
"We also would ... | [
"Thanks for your response. Putting dark matter here was a mistake.",
"Also, I thought that that Big Bang was like actual explosion, and expansion of Universe was a galaxies moving through space because of impulse they get as result of that explosion.",
"But it's the space expanding itself plus the galaxies movi... | [
"Pretty much, calling it the big bang is rather misleading since it wasn't an explosion but rather all of space rapidly expanding from a single point. We don't know how the universe will end but there are 3 solutions based on wether or not expansion continues, stops or reverses. The big crunch suggests that the uni... |
[
"Why does MRI use helium as cooling?"
] | [
false
] | I have read a bit about helium shortage and I just wonder why MRI-scanners does not use high temperature superconductors which could be cooled by nitrogen but is instead cooled by helium. Is the high temperature ones not strong enough, durable enough or what is the reason behind this choice by the manufacturers? | [
"The answer that I got to that from my old NMR grad-course teacher, was that that high-temperature superconductors can't handle the (huge) amounts of current required."
] | [
"It's also that high-Tc superconductors tend to be brittle ceramic materials and can't be made into wires the same way that metallic superconductors can."
] | [
"I guess that sounds logical. Thank you for your answer!"
] |
[
"Does a female express/pass on epigenetic changes in their germ cells?"
] | [
false
] | [deleted] | [
"A lot of the fun correlates that have been found (and are often cited on Reddit)",
"The \"grandparent starvation > grandchild obesity\" link the example I've heard. It seems to me there are many alternative explanations that don't involve epigenetics. For example, socialization, prenatal stress or selective mati... | [
"First things first, we are not sure how much epigenetic changes can be inherited. We know that sperm and eggs can have marks and packaging, but when the embryo is developing it appears to erase most marks and reform its chromatin state ",
"[1]",
". This is a less sexy idea but it is important to keep in mind. ... | [
"Do you mean that noncoding RNA from the egg cells persists after fertilization? If that's true, it could affect the gene expression in the zygote. But the embryo doesn't form until 2-3 weeks later, so I doubt it would affect the embryonic development. The half-life of miRNA/lncRNA is only a few hours, right?",
"... |
[
"Is There Any Scale Where The Distribution Of Electric Charge Within A Neutron Is Relevant?"
] | [
false
] | A neutron contains valence quarks with both positive and negative charges so tightly bound that on most if not all conventional scales the baryon as a whole can be treated as a single electrically neutral particle. My simplified layman’s understanding is that the strong force typically dominates the electromagnetic for... | [
"The charge distribution asymmetry of a neutron would manifest itself as an electric dipole moment, but so far there has been no nonzero measurement of the neutron electric dipole moment. So, it's safe to say that it's pretty irrelevant. If we could detect it, it might indicate \"beyond standard\" physics, because ... | [
"It's really cool to see my area of research here. I work on the neutron electric dipole moment experiment for Oak Ridge National Labs. So far, searches for the neutron EDM have found nothing to the level of 10",
" e*cm. This is so small that, if you blew up the neutron to the size of the earth, the separation be... | [
"As a layperson, it's equally cool to see such an interesting question addressed by someone who's hands-on with current research. Thanks so much for the contribution. :)"
] |
[
"Why do all the gas giant planets exist past the asteroid belt?"
] | [
false
] | [deleted] | [
"I'm also not an expert on planetary formation, but I wanted to point out that the sun is powered by fusion, not fission. "
] | [
"I can't tell if you're trolling, so I'll just leave this here:",
"\n",
"https://en.wikipedia.org/wiki/Nuclear_fusion"
] | [
"I'm more of a rocky planet guy, but I'll relate what I learned in graduate school. The gas planets formed on a much smaller timescale than rocky planets, and seemed to do so without accretion (the process by which rocks collide to form meteors collide to form planetessimals collide to form planets). A little over ... |
[
"How does a transplanted heart get signals from the body post op? As far as I've seen in me brief research they only reconnect the blood vessels, not the nervous system."
] | [
false
] | Without signals coming from the brain, how does the heart know to increase rate when the muscles and brain require more oxygen during exercise? Is it a chemical process, or is there something else at play? | [
"The heart has an inbuilt natural pacemaker (SA node). The brain controls the heart rate chemically through the blood stream with norepinephrine and adrenaline."
] | [
"This is broadly correct, but it's worth pointing out that a non-trivial number of people receiving a heart transplant require a permanent pacemaker to achieve a satisfactory heart rate - I don't recall the precise figure, and I don't have access to journals at this computer, but I believe it's around 15%.",
"Lef... | [
"Here",
" is a very interesting research article on exactly the topic of your question! The previous posters have already touched on the more important parts of their conclusion, but in case you don't read this understand that heart rate post transplantation is caused to increase during exercise due to: the catec... |
[
"What happened to the hole in the ozone layer?"
] | [
false
] | null | [
"Here's a neat article about it: ",
"http://www.smithsonianmag.com/science-nature/ozone-hole-was-super-scary-what-happened-it-180957775/",
"Though I know most don't come here for a long read so here's the tl;dr:",
"The hole being discovered contributed greatly to its reversal. Had it not been, it would have b... | [
"Two things:",
"The ozone hole has always been a temporary phenomenon. It occurs in early spring in the Southern hemisphere for a period of a few weeks to a few months depending on conditions. This is due to the dynamics of ozone creation/depletion and the buildup of ozone destroying chemicals in the upper atmosp... | [
"Thalidomide is actually quite interesting. There's a type of thalidomide that is completely harmless and works as it should. The other causes horrible birth defects but still works. These two types come from stereochemistry when producing the compound. It is very possible to separate the two types. Sounds great, r... |
[
"We can only notice the progression through time relative to our own immediate environment. If there were a spaceship far away, how would they calculate time in relation to Earth's relative time?"
] | [
false
] | [deleted] | [
"You mean like if you wanted to keep an accurate Earth calendar, for historical reasons or whatever? The difference would be on the order of microseconds per day, at the absolute most. I don't feel like doing the maths to figure out the time dilation between the surface of the Earth and flat space right now, but it... | [
"More than you'd care to do. There'd be tensors involved, let's just put it that way.",
"In practice, you'd just use pulsars. There are hundreds of them, they're extremely well mapped, and most of them are sufficiently rigidly periodic to be used as reliable clocks wherever you happen to be in the universe, as lo... | [
"More than you'd care to do. There'd be tensors involved, let's just put it that way.",
"In practice, you'd just use pulsars. There are hundreds of them, they're extremely well mapped, and most of them are sufficiently rigidly periodic to be used as reliable clocks wherever you happen to be in the universe, as lo... |
[
"How close to a black hole could a human get before death?"
] | [
false
] | And how would we die? | [
"It really would depend on the size of the black hole. But this entry on ",
"Spaghettification",
" explains it fairly well."
] | [
"Wouldn't most black holes have a fury of particles circling them at relativistic speeds. So when you reach anywhere near event horizon you just \"burn away\"?"
] | [
"I am only speculating on this, but if the black hole is not actively feeding you aren't likely to encounter enough high energy particles to kill you. "
] |
[
"What is the significance of parity violation in physics?"
] | [
false
] | null | [
"This issue is not easy to summarize concisely. Parity violation is now known to exist, it is not a welcome addition to physics because it requires an unpleasant \"gimmick\" added to an otherwise nice symmetrical theory, but it also may explain why there is any matter at all.",
"It turns out that, if there were p... | [
"Er, I think that OP was just asking about P violation, though."
] | [
"Yes, I noticed that, but without a larger context it might not seem to be very important -- or easily explained."
] |
[
"Do the eyes have any type of influence on what we \"hear\"? Details inside."
] | [
false
] | So, interesting problem that happened to me. I am viewing this image of a maze, it's black on white color, and it's in a zoom to where the density of the black and white pixels become somewhat disorienting. Now the interesting part: when I zoom in to a certain extent, I hear a high-pitched sine-wave-like whine in my ea... | [
"I don't know what's happening in your particular case, but the answer to the topic is \"yes\".",
"The ",
"McGurk effect",
" is an example of how our vision can affect what we hear. And if you want to see/hear it for yourself watch this: ",
"http://www.youtube.com/watch?v=G-lN8vWm3m0"
] | [
"Sounds like synaesthesia to me"
] | [
"It seems like it's the monitor making the noise. I continue to hear the noise even when I look away. I'll leave the explanation on why the monitor buzzes to someone smarter."
] |
[
"If laughing is caused by a surprised brain/learned something new, why isn't learning Algebra funny?"
] | [
false
] | Video I came with the though from: | [
"Laughter is much more complicated than that. "
] | [
"Because math isn't funny, ",
"it's pain incarnate."
] | [
"This isn't very scientific, but there's a word for this in Buddhism called \"satori\" -- similar to \"awakening\". It's sort of an \"ah ha!\" moment, as far as I understand. In that sense, the two things you've described are both \"funny\". "
] |
[
"Why are the planets in our system different?"
] | [
false
] | Aren't the elements and compounds which our planets are made of forged from the same star? Why is mars so different in composition than earth? Why are all Jupiter's moons so unique if the stuff they are made from comes from the same place wouldn't we expect more uniformity? Are the elements distributed unevenly in our ... | [
"I can't give you a complete answer, but seeing as no one's commented yet, I do know that a major factor is the ice line; the distance from the sun within which water in space does not exist as ice. When the planets start to form, the ones within this line can only form from dust, while the ones outside form from d... | [
"Not necessarily: We've observed gas giants around other stars that orbit extremely close, closer even than mercury. Since they can't form that close, so we assume that they slowly migrated inwards after formation."
] | [
"Also if a planet in Earth's zone got to the size of Jupiter, gravity would cause it to fall into the Sun."
] |
[
"Can a inductor limit DC transient currents?"
] | [
false
] | Let's say I have a DC constant voltage source. I plug a resistive load subject to voltage transients (infrequently but periodically adding and removing loads at intervals, loads that vary from one steady state to another under operating conditions, etc). If I want to limit the transient currents while holding the stead... | [
"To a certain extend you are absolutely right, inductors are definately used for exactly that reason. But you kind of have to be careful how exactly you use the inductor because the back-emf that they generate when you change the load can also appear in the rest of your circuit. This all depends on where you put th... | [
"a resistive load subject to voltage transients (infrequently but periodically adding and removing loads at intervals, loads that vary from one steady state to another under operating conditions",
"With an ideal DC source and a resistive load, you should not have large transients from changing loads. Reactive loa... | [
"Thank you for the help and book suggestion. So for a single switched load that is not information carrying and has a duty cycle longer than the inductor discharge time, there's no issue. An inductor in series with the load is OK.",
"To capture back EMF, putting an electrolytic and small capacitor in parallel wit... |
[
"How much force would I really need to push a steel rod that is 1 light-year long, on a distance of 1 m?"
] | [
false
] | Such a long rod would have an astronomic mass, that seemingly would be impossible to move with human-accessible forces. However, as the movement would take a very long time (50 000 years according to by of another question). So according to my understanding, I could push the rod with a much lower force, as my extremity... | [
"Yes. Here's the calculation of what you outlined.",
"Suppose it's steel. 200 GPa modulus (Y) and 8000 kg/m",
" density (rho). The characteristic impedance for compression wave propagation is sqrt(rho Y) = 40 x 10",
" sqrt(N kg/m",
" = 40 x 10",
" sqrt(N",
" s",
" / m",
" = 40 x 10",
" Ns/m",
... | [
"You're missing the entire point of the question. It's not to apply Newton's law, it's how the sound transmission will effect how you push it. He's probably right, your push wouldn't see anywhere near that much mass like you are calculating, the elasticity of a metal rod would likely approach some value on an infin... | [
" ",
"u/kilotesla",
" ",
" ",
"The rod will still have to obey the laws of physics, in particular Newton's second and third laws. The second law tells us that F = m·a, so the force we need to apply depends on how much acceleration we want to impart on it. The third law tells us that as we push on the rod, t... |
[
"When I brush my teeth, what's more important—the brushing or the toothpaste?"
] | [
false
] | Which would leave my teeth better off: brushing my teeth with no toothpaste for a year or putting toothpaste on my teeth for a year without brushing? | [
"Brushing the important part, the mechanical action of the bristles break up the biofilm created by bacteria, loosening up the bacteria so they can be rinsed out and of course clears out food residue that may be stuck in crevices.",
"If you go without brushing, but just gargle with toothpaste and regular mouth wa... | [
"The fluoride in most toothpaste does help in a variety of ways: making the enamel less soluble, remineralizing the enamel, and reducing the acidity of plaque-causing organisms . ",
"source"
] | [
"Many apes and monkeys do, as well as dogs and some predators who chew bones and hide."
] |
[
"How can the body survive without blood? How does the body get oxygen? Human trials of suspended animation is scheduled to begin soon at the UPMC Presbyterian Hospital. They plan on replacing the patients blood with chilled saline, in order to slow down bodily functions and prevent blood loss."
] | [
false
] | It seems strange for me to take out the blood in order to save the body from blood loss. I wouldnt think the body could last long without blood. | [
"From the linked article in OP's article:",
"In this state, almost no metabolic reactions happen in the body, so cells can survive without oxygen. Instead, they may be producing energy through what's called anaerobic glycolysis. At normal body temperatures this can sustain cells for about 2 minutes. At low temper... | [
"Cold blood is also very viscous, and can crystallize. It probably couldn't pump very efficiently. "
] | [
"If we had enough blood to do that, we wouldn't even need to do the freezing thing. Blood supplies are valuable. Also blood is a complex mixture which is likely harder to cool (takes more energy) than just saline. "
] |
[
"What kind of adaptations would be expected for life that's been in a cold, Antarctic lake without light for 20 million years?"
] | [
false
] | Would anything even still be alive? | [
"I don't know. A lot of deep sea creatures have photo receptors of some sort. Other species down there have evolved bioluminecense to cater to exactly those eyes!",
"I am hoping they find a stargate down there, personally... "
] | [
"I don't know. A lot of deep sea creatures have photo receptors of some sort. Other species down there have evolved bioluminecense to cater to exactly those eyes!",
"I am hoping they find a stargate down there, personally... "
] | [
"Organisms would use chemosynthesis; look up Blood Falls under Taylor glacier for example."
] |
[
"What is the definition of observation (in a quantum mechanical sense)?"
] | [
false
] | What is it about looking into the box in schrodinger's experiment makes it pick a position? the gravity and what not of the alive/dead cat (whose spacial position would change based on living or dead) and surely other things would effect the world outside the box effectively as much if i looked in the box or not... als... | [
"An observation is just an external interaction. It's not quite the same thing (there exist interactions which do not count as observations), but for most purposes you can treat them as the same. So the fact that something interacts with the inside of the box is what causes the superposition to collapse.",
"Of co... | [
"\"Schrödinger's cat\" is ",
" It's not even a ",
" experiment. It's just a metaphor.",
"If you ever find yourself thinking about the ",
" of cats and boxes — as you appear to have here — you've gone off into the weeds. You need to pull yourself back to reality."
] | [
"Then the next question is \"well what's the cutoff between classical and quantum and why is it there?\". People just don't find any answer to that question satisfactory, so I make sure to dodge it whenever possible."
] |
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