title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"The difference between Microwaves and radar?"
] | [
false
] | If my microwave oven operatates at 2450MHz because it easily penatrates layers of food and gets absorbed by water; Why is RADAR so different at 2700-2900MHz, radar works well because that frequency range reflects off everything providing the return. It seems like such a small difference in frequency shouldn't change t... | [
"Scientifically, radio waves (such as used in radars) and microwaves are the exact same thing. They both describe electromagnetic waves that are lower in frequency than Terahertz. On the sub-meter scale, these words are used interchangeably.",
"The microwaves used by your microwave have the same frequency as the ... | [
"The only thing I have to add to this is that microwave ovens were ",
"invented by accident",
" when a radar engineer walked in front of a magnetron and noticed that the candy bar in his pocket was melting."
] | [
"Weather radars such as wr88d get reflections from rain and water where microwave ovens absorbs into water to provide the heat. Is this not accurate?"
] |
[
"How long would it take for Earth's orbit to be affected if the sun were to suddenly blink out?"
] | [
false
] | null | [
"The effect of gravity does travel at the speed of light, so the earth would cease to orbit, and travel in a straight line after 8 minutes 20 seconds."
] | [
"Approx the same time as us finding the lights going out, as gravity (they now say) travels the speed of light. I think this is about 8 minutes. "
] | [
"It's not known for sure whether the effects of gravity travel at the speed of light. It's assumed that the effect of gravity is subject to the speed of light (because of issues with causality), but it's still an open question, and there is a lot of research being done in this area.",
"If the sun suddenly change... |
[
"Where does the energy come from for new vacuum?"
] | [
false
] | As I understand it, (1) any volume of space (even vacuum) has an associated energy, (2) the universe is currently expanding, and (3) energy is conserved. This implies that somehow, other forms of energy are being converted into vacuum energy. Do we know the mechanism for how energy is converted to vacuum? This seems ... | [
"The conservation of energy only holds for certain types of closed systems. The expansion of the universe breaks this rule, so there is no requirement for the total energy content of the universe to remain constant through time.",
"So yes, energy can be both gained and lost on cosmic scales. The total amount gain... | [
"One interesting note is that in your counter-example, photons lose energy due to expanding space. If the photons are losing energy, and the vacuum is gaining energy, is it not still possible that the total energy is conserved? You claim that the energy is \"going nowhere\" but it could be being used to create new ... | [
"Nope, they can't equal out like that. The energy lost from all photons decreases non-linearly through time (toward zero energy), while the increase in energy from vacuum energy increases linearly through time (same energy density, but constantly more of it).",
"Besides, there are already perfectly usable equatio... |
[
"What happens in the brain when an individual becomes \"psychologically addicted\" to something, be it an illicit substance, a favorite food, or an activity?"
] | [
false
] | My question is about psychological addiction only, not physical addiction. I have an addictive personality... I have to be very careful what hobbies or activities I'm involved in, because it is very easy for me to become obsessed with it. At the moment I'm obsessed with reading (I've been going through 2-3 books a week... | [
"Physical addiction and psychological addiction are highly intertwined. ",
"The release of dopamine in response to novel experiences promotes instant gratification rather than long-term reward. It's likely that you're replacing one obsession with another once the newness and the increased dopamine release wears o... | [
"Man, I loves me my dopamine. It got me to quit smoking!"
] | [
"Usually it's because the reward circuits in the brain are engaged in something. A recent study on ",
"food addiction",
" shows part of the story.",
"For addicts, of the good or bad type, it's not usually a particular thing, rather, they have their \"go-to\", or preferred substance."
] |
[
"Why is it so difficult to do something with your right hand, while simultaneously doing something different with your left hand?"
] | [
false
] | [deleted] | [
"because you only have one brain. People who have a severed ",
"corpus callosum",
" in effect have two separate brains and can do different things with their two hands, at the cost of experiencing the world quite differently from the way most people do."
] | [
"Well, I am a piano player and I've never been able to truly dissociate the hands. It's true, I can have the left hand playing a bass line while the right plays a melody - but they are both part of the same song. I don't think I could play two completely independent songs at the same time."
] | [
"It's also a skill that can be learnt with practice, think of a piano player and how they use their hands. "
] |
[
"With our current technology, what is the furthest possible exoplanet we could detect to have chlorophyll?"
] | [
false
] | null | [
"I found ",
"this paper",
" to be quite readable on the subject. Here's the tl;dr version:",
"You have to directly image the planet in order to do it because you need to look at the spectrum of light coming from it.",
"O2 is twice as hard to detect compared to H2O",
"chlorophyll will be 6 times more diff... | [
"Might be worth pointing out that life on other planets might not rely on chlorophyll for photosynthesis. It's quite possible it would use other pigments with absorbtion spectrums more optimized for the light from the nearby star (or stars).",
"Edit: ",
"Here",
" is a NASA news article about it."
] | [
"James Webb Space telescope, which is launching in 2018, might be able to do that. I'm saying might because chrolophyll levels are very low and might not be detectable. Distance wise I think we are talking in the hundreds of light years.\nThe whole sky will be surveyed so I expect 1000s of exoplanets to be analyzed... |
[
"With all the talk about opening windows in spaceships.. what happens to the air?"
] | [
false
] | What would happen? Does the air get 'sucked out' with some sort of pressure? What would happen to that air? Would there be an air bubble floating around somewhere in space? | [
"The air would get sucked out because of the pressure difference between the inside and outside of the ship. Inside the ship it would be approx. 1 atm (if it were for humans) and outside the ship it would be approx. 0atm. The air would run out and dissipate into the vacuum."
] | [
"I see your point. The thing I was trying to convey is that there isn't some magical 'suction force' that exists in the vacuum of space and pulls the air out somehow."
] | [
"I would say it does get sucked out. There is a partial vacuum due to the pressure gradient, which reaches equilibrium by pulling large quantities of air out of the ship very quickly. You could alternatively say that the higher pressure inside the ship \"pushes\" air out, but it's just a matter of semantics. "
] |
[
"Is There a Limit To How Hot Something Can Get?"
] | [
false
] | [deleted] | [
"It depends on whether you are speaking of a small finite system or not. For a small finite system (like a handful of atoms), you can end up with negative temperatures which are hotter than any positive temperature, and so there is an 'absolute hot' which happens to be 0 (or arbitrarily close to it at least, just l... | [
"Can you give an example of one of these small finite systems (Hopefully in an experimental paper)?"
] | [
"It's been a few years since I've studied statistical mechanics, but the most basic example I can think of is called the Ising model. I'll try to explain a simple example intuitively. Let's say you have a few particles in a line, and each one can have 'spin up' or 'spin down'. Usually, every particle wants to have ... |
[
"Does anyone get disorders that make them feel good or happy?"
] | [
false
] | null | [
"Mania",
" and hypomania often cause the person to feel energetic, ecstatic, and capable of anything. It often alternates with periods of depression though."
] | [
"I wonder if you could identify and classify some instances of addiction as \"a disorder that makes a person feel really good\" in the sense that some rather menial act, say eating pieces of non-psychoactive chalk or dryer sheets(saw a woman doing this on tv)--done repeatedly--has the effect of satisfying said pers... | [
"Yeh I was thinking more something that's fairly consistent. For instance, I suffer from fairly extreme anxiety disorder. It's a 24/7 condition that I need to control. Say you have a normal state, the brain may fluctuate a certain percentage above or below this normal state. Well in my case, my normal state would b... |
[
"The Dirac model of the positron"
] | [
false
] | So I'm reading Dirac's biography and I'm at the part where it talks about his model that there is a sea of electrons filling up all the negative energy states that his equation/theory predicts. And that a hole in this sea behaves like an anti-electron, when the hole and the electron meet they annihilate i.e the electro... | [
"1.First is the charge, From what I understand the electron wants to drop down to the lower energy configuration, so the hole appears as if it has a positive charge but how was it predicted that the charge would be the exact same magnitude as the charge of the electron.",
"So I have this sea of filled negative en... | [
"Before we pop out the electron, the sea of negative energy states naively has some horribly divergent (infinite) amount of charge there. -100000000000000000whatever *e. But in such a scenario with uniform charge everywhere in space you wouldn't observe it, so you can call that state 0. It doesn't matter what the ... | [
"\"So I have this sea of filled negative energy states, and I pop up a single electron with some charge -e. That electron is no longer in the sea. So the current charge of the sea minus the initial charge of the sea is -(-e) = +e.\"",
"Not sure I follow this, when the electron is in the negative state is there 0 ... |
[
"Why does warm water freeze faster than cold water?"
] | [
false
] | null | [
"This is called the ",
"Mpemba Effect",
"; it's mostly an issue where the term \"freeze\" isn't defined rigorously enough. To quote from the article directly:",
"Although widely mentioned there are very few, if any, modern descriptions of exactly what the effect is and how it may be observed.",
"This",
" ... | [
"You'd think somebody would have rigorously tackled this one by now. "
] | [
"The problem is that there are a huge number of variables to consider, and \"average temperature\" is not a very good descriptor of the physical state of a bowl of water."
] |
[
"Why does Australia have such high concentrations of uranium?"
] | [
false
] | null | [
"Australia doesn't have high concentrations of uranium. Australia has very large deposits of low concentration uranium (which is exactly what you want if you're mining it).",
"As far as how the deposit formed it was most likely magma meeting seawater a very very very (very very) long time ago. But no-one is 100% ... | [
"Australia has very large deposits of low concentration uranium",
"So the country has a high concentration of low-concentration uranium deposits?"
] | [
"If we cancel everything out, Australia has concentration of uranium, then"
] |
[
"What makes a sugar be a sugar? And what makes it taste sweet?"
] | [
false
] | null | [
"A sugar is a class of molecules, so you could say that what makes a sugar is its molecular structure. Loosely, a sugar consists of carbon atoms with each carbon bound to a hydroxyl group ( oxygen + hydrogen) and a hydrogen atom. Another way to say this is a molecule with equal number of oxygen and carbon atoms, an... | [
"On taste it’s worth mentioning that your tongue can tell the difference between glucose and fructose - fructose will taste sweeter. But fructose is just a structural isomer of glucose, meaning it’s the exact same number of carbon, hydrogen, and oxygen atoms, but the carbonyl (a C double bonded to an O) has moved o... | [
"Examples of bland polysaccharides:"
] |
[
"How deep could a human go under water and still use a snorkle?"
] | [
false
] | At what point does the air pressure exceed the exhale pressure of a typical human? Meaning spent air could not be expelled to make room for fresh air. Would the pressure keep you from inflating you lungs before you reach this depth? Or would your body be crushed? Assume the snorkle doesn't buckle or crumple under pres... | [
"For a typical healthy adult, the answer is... ",
".",
"Two primary reasons:",
"Breathing through a long tube adds dead air space to one's respiratory system. Not all exhaled, oxygen-depleted air will exit the far end of a long tube. If it remains in the tube it will be repeatedly reinhaled, and gradually a... | [
"Wouldn't this same issue occur for SCUBA divers, or is tank pressurization overcoming this?",
"Bingo. That's why (well, that and capacity issues) you need a highly pressurized tank to dive to any appreciable depth. The regulator that is part of a SCUBA is what ensures the air is delivered at the same pressure a... | [
"Wouldn't this same issue occur for SCUBA divers, or is tank pressurization overcoming this?",
"Bingo. That's why (well, that and capacity issues) you need a highly pressurized tank to dive to any appreciable depth. The regulator that is part of a SCUBA is what ensures the air is delivered at the same pressure a... |
[
"Is there a correlation between how hungry a person is and how efficiently his body processes food?"
] | [
false
] | In other words, can someone who's hungry absorb more nutrients than when not as hungry? If so, is there an "optimal hunger level" to attain the most efficient nutrient intake? Edit: added words | [
"Well, when you think about, smell, or taste food, signals will be sent neurally to the stomach for it to start the digestion process (secretion of gastrin, etc). So the more you think about food, the hungrier you will become, the more gastrin and stomach acid will be produced, making digestion of a meal more effic... | [
"I would like to comment that this implies that the food would be ",
" more efficiently/speedily. It does not however, necessarily follow that more nutrients are ",
" as those nutrients may be absorbed even with less efficient/speedy digestion.",
"I do suspect there is some upper bound where you ate so much t... | [
"While digestion is discussed above, it is only a small factor.",
"Hunger is usually indicative of blood concentration of glucose via Insulin/Glucagon ratios. High hunger is indicative of low insulin, and low blood glucose.",
"Insulin and glucagon have various widespread effects on the internal energy utilizati... |
[
"Is there a word or theory about this? The longer you wait for an event with an unknown ETA, the less likely it is to happen in the next few moments."
] | [
false
] | null | [
"As Midtek says in his post, random events are often modeled by the Poisson distribution. This makes the waiting times to first event occur in an ",
"Exponential Distribution",
". If you are waiting for such an event, and you know the exact mean of the distribution (that is, you know exactly how likely the even... | [
"Waiting times are usually approximated by a Poisson distribution, which has a memoryless property. That means the chance of having to wait at least T more units of time never changes, no matter how long you have already been waiting. To be precise, if X is your waiting time,",
"P(X > T+S | X>S ) = P(X > T)",
"... | [
"Though ",
"/u/Midtek",
" beautifully explained the memorylessness of the exponential/Poisson distribution, I think what you're looking for may be more complicated. Basically, while the other comment pointed out the typical assumptions for which distribution the ETA is drawn from, what you seem to ",
" care a... |
[
"What actual improvements are made year-to-year to improve mileage on cars?"
] | [
false
] | I am learning about Otto and Diesel engines in ChemE Thermodynamics, and we talked about the volumetric ratios in pistons as a main way to increase the efficiency of an engine. However, my professor noted that it hasnt really changed much over time (from 6 or 7 in the mid 1900's or so to 8 or 9 today). I'm wondering th... | [
"Continuously variable transmissions (CVT) - allows for engine to run more of the time at its most efficient RPMs",
"Electric power steering assist (as opposed to hydraulic) which only uses power when needed. Belt-driven hydraulic power steering is always pumping regardless of need - can cause loss of ~1 mpg",
... | [
"The big thing to keep in mind here is that while they might not be nearly as efficient, they're a ",
" safer. That safety comes at a price: weight. Keeping the same efficiency as before while carrying extra weight is in itself pretty impressive."
] | [
"I think the engine control is a large part of it. Those systems are getting more advanced, and they keep adding sensors and more tightly modeling the engine so they can change what it's doing to be more efficient."
] |
[
"Do individual sex cells carry a random copy of each chromosome?"
] | [
false
] | Sorry I realize this is an extremely basic Q but I've got next to no understanding of Biology. To expand on the Q, my understanding is that each sex cell has 1 copy of each chromosome, and an individual has 2 so would each sperm cell have a (50/50) random chance of having the 'Female' or 'Male' copy of chromosome 1 and... | [
"During ",
"meiosis - the process that generates sperm or egg sex cells",
", the paternally-derived and maternally-derived chromosomes undergo recombination via cross over. It is the crossed-over single chromosomes that get sorted into the haploid (single copy of each chromosome) daughter cells. [",
"Intro le... | [
"Since others have explained meiosis, I'd just like to point out that it isn't the sperm who 'wins the race' that fertilises the egg. Rather, the egg has a protective coat that prevents the sperm from getting in. Each sperm has an enzymatic coating on the tip of its head that it can use to break down this coating t... | [
"That is pretty much how it works, although to be clear, with the exception of the \"Y\" chromosome, none of the other chromosomes are gendered, but it is a 50/50 shot for each chromosome pair whether the individual sperm or egg will get the maternal or paternal-sourced chromosome. "
] |
[
"Do animals see the world differently according to the way their eye is shaped?"
] | [
false
] | While a human pupil is round, a reptile's eye would have more of a vertical shape, while a horse would have a horizontal shaped pupil. | [
"Yes, and the effect is very large for ",
"blurred images",
", i.e. parts of the scene which the animal hasn't brought into focus. In that photo, a vertical-slit pupil would sharpen up the blur in the horizontal direction, and also change all the bright highlights into little vertical eyeslit-images.",
"Sp... | [
"The short answer is yes! Pupil shape can influence distance perception, peripheral vision, and light intake. Also, eye placement is a very influential factor in vision range (e.g. if an animal's eyes are on the sides of its head, they can't see well in front of them). Here's a cool paper all about vertebrate visio... | [
"Are there any non-predators with vertical slit pupils?",
"Apparently not."
] |
[
"How does a local anaesthetic differ from a general one?"
] | [
false
] | What keeps the effect contained? | [
"How much is actually known about general anaesthetics?"
] | [
"How much is actually known about general anaesthetics?"
] | [
"http://www.reddit.com/r/askscience/comments/g2znp/hey_askscience_how_do_anesthetics_work/"
] |
[
"Is there any evidence that animals like music?"
] | [
false
] | Sometimes when I'm playing loud music in my home or my car, I feel guilty that I'm subjecting my dog to it. I tell myself she might like it [either because she may associate it with me or because it's inherently "good"]. | [
"Some ",
"birds",
" and even ",
"seals",
" can keep a beat, which is quite impressive in itself, but there isn't as much evidence that animals actually 'like' music because that's just a hard thing to measure."
] | [
"They have done studies with monkeys to show that they are responsive to music.",
"They made specialized music that triggered various emotions like calming and fear. ",
"As far as human music goes, monkeys seem to find Metallica very calming.",
"If you want to hear the specialized monkey music or read more ab... | [
"Happiness is subjective, so it's a hard thing to quantify in the first place. On top of that, it's hard to determine whether an animal is happy; its not like you can just ask them. It's not impossible, but it's a tall order to work out something so specific."
] |
[
"Why do some birthday candles re-light themselves after you blow them out ?"
] | [
false
] | What happens in that there candle light, you know, scientifically speaking. | [
"Most candles are just wax and cotton. The trick candles have magnesium in order to relight themselves."
] | [
"Wikipedia",
":",
"These candles relight themselves, using a fuse similar to those in dynamite sticks, the principle being that by igniting magnesium inserted into the wick of the candle, the paraffin vapour given off when a candle is blown out can be set alight, and through this, the candle can reignite",
"M... | [
"Do all candles have magnesium ? Do they randomly have that in them ? Thanks for your ansewer."
] |
[
"Tensors in engineering mechanics: Can someone explain them to me in an intuitive, satisfying way?"
] | [
false
] | That's it. I give up. I've spent a few weeks scouring the internet for a an explanation of tensors in the context of engineering mechanics. You know, the ones every engineering student know and love (i.e. stress, strain, etc.). But alas, I cannot find any explanations of tensors without running into crazy abstract form... | [
"If you want to avoid all the crazy abstract math stuff, then in the context of engineering you can think of them as \"Generalized Dot Products\". They aren't \"arrays of numbers\" or \"generalizations of scalars, vectors, matricies\", they are \"Glorified Dot Products\".",
"If (x,y) is a row vector and (u,v)",
... | [
"I wish I had read this when I was still in school."
] | [
"I'd like to add an intuitive explanation for what's up with different numbers of row and column vectors that a tensor acts on and why a linear transformation is a tensor (at least as the term is used in maths), but there are other rank-2 tensors that are not linear transformations.",
"Imagine that you have a 3d ... |
[
"Since time is relative, how do we define it when we say that the universe is 13.8 billions years old ?"
] | [
false
] | null | [
"It depends on how we measure it, but all reasonable reference frames give about the same value.",
"The most precise measurements are based on the ",
"Cosmic Microwave Background (CMB)",
". There is a convenient reference frame called the ",
"comoving frame",
", in which the CMB light coming from all dir... | [
"Questions are what we're here for! Unfortunately I can't give an explanation much more satisfying than saying that as far as we can tell, the universe is consistent with a solution of general relativity called the ",
"Friedmann–Lemaître–Robertson–Walker metric",
", which assumes among other things that there ... | [
"What's the significance of the comoving frame? Must there exist a frame in which CMB is isotropic? Is it different elsewhere in the universe? Why is it so close to our current speed?",
"Sorry about all the questions, but this is really interesting."
] |
[
"Does red-green 3D work for red-green color blind people?"
] | [
false
] | I just had a discussion of how the current 3D-glasses work and the question came up. | [
"yes, it would, and potentially better.",
"with some simplification, what looks red before glasses is light of \"red\" wavelength, and what looks green is light of \"green\" wavelength. only the green light can pass through the green glass, so in effect, the \"green\" eye gets a \"green or black\" signal, vice ve... | [
"Isn't it red/cyan?"
] | [
"i have not tried red/green 3d for some time",
"Generally speaking, anaglyphic 3D has been red/blue for most applications, although multiple view polarisation and active shuttering are surging ahead, especially in consumer devices."
] |
[
"Why does the nucleus of an atom increase in mass when it is broken apart?"
] | [
false
] | Why do the nucleons (protons and neutrons) of an atom weigh more when separated then when combined into a nucleus? | [
"The extra mass ",
" the binding energy. Mass is really a form of energy, and the binding energy needed to form the nucleus is deducted from the mass of the nucleus' constituent particles."
] | [
"E=mc",
" therefore energy and mass are the same thing. Generically, energy has only two forms: kinetic (i.e. \"movement\" energy) and potential (from interaction). Crucially, when adding up the energy of something, the kinetic energy has a positive sign and the potential energy has a negative sign (under some... | [
"So why does the nuclei form? Because it is forced to or because the parts like each other?"
] |
[
"Do multilingual people have a slightly different personality associated with every language they speak?"
] | [
false
] | null | [
"Yes and no. :) There's a growing amount of evidence that perception, context, association and other things do change as you change languages. But personality, by definition, is stable across different situations. ",
"http://sapir.psych.wisc.edu/papers/scudellari2016.pdf"
] | [
"Subjectivly, having that I speak fluently two languages, and lived in those two coutries of very different societies for pretty long time , I think yes, since I will switch my fundamentals and framework of social traditions, habits, concerns, and concepts depending on the language I speak, this leads to pretty di... | [
"Hmmmm... a bit of a strange question. Personally, I view personality as a rather fluid and ever evolving construct of identity (meaning \"slight changes\" are normal).",
"But Is personality partially dependent on spoken language? I think a more accurate way to phrase this, is that knowing multiple languages alte... |
[
"The orbits of the stars around the Milky Way's black hole are really, really wonky. Why?"
] | [
false
] | Why is it that what I expected to look like actually look like It looks so irregular and asymmetrical, why hasn't it settled into a flat plane like the rest of the galaxy, or our solar system? | [
"Your first picture is of an accretion disk, which is not made of stars, it's plasma slowly transferring angular momentum through viscous heating until it can fall onto the surface. The material in an accretion disk is in orbit, but it's constantly rubbing against material both above and below it so it can transfer... | [
"Actually our galaxy is a little more interesting than that. The Milky Way appears to be composed of a disk, central bulge and a halo. By looking at the ages of stars in each part of the galaxy, we can try to infer how the galaxy formed.",
"As for your question, the density of the galaxy increases greatly as yo... | [
"Our galaxy and solar system both formed from collapsing clouds of gas and dust, and the angular momentum of those clouds flattened them out into disks. The center of a disk galaxy, however, tends to have formed earlier than the rest of the galaxy, from collisions between a lot of smaller gas clouds and \"baby gala... |
[
"What is the best way to search for something on the ground?"
] | [
false
] | [deleted] | [
"This is a really interesting question, and I'm disappointed that it got downvoted!",
"There are a few solutions that present themselves to me immediately. These might not be the best, but they're the ones that come to mind.",
"First, there are a few variables you have. These are: Positional accuracy/precisio... | [
"Thank you for your answer, I was hoping someone in your field (archeology) would answer :) It's actually what you guys do, no? :)",
"Yes, we already have the form and we're mapping only the large deposits (over 1m",
" ).",
"The population density idea is a very good idea; it will maximize the garbage found; ... | [
"Oh, I forgot about elevation changes. You could theoretically combine elevation and population density to find a most efficient search area per volunteer Calorie expended, if you wanted to use your volunteers energy most efficiently. Fun!",
"You might want to take pictures of the big garbage dumps you find, or... |
[
"How do snails survive freezing in winter?"
] | [
false
] | null | [
"Snails use a variety of strategies to survive freezing winters. Some are able to burrow into the ground, insulating themselves from the cold. Some species can excrete some of their water and break down proteins to increase the osmolarity (the concentration of dissolved solutes in their bodily fluid) which reduces ... | [
"That is all very cool, thanks."
] | [
"Thanks for sharing"
] |
[
"Why do \"elastic materials\" lose their stretchiness over time and use?"
] | [
false
] | Forgive me if I use the wrong terminology, but why do "elastic materials" (rubber bands, bungee cords, etc) lose their "tightness" over time and use? I would think that they are solids, and thus would return to their original form, but after a period of time they lose that ability, become longer/more stretched, and mor... | [
"Stress, load per unit area, divided by strain, unit deformation or deformation per total length, is idealized as elastic to a point then inelastic or plastic after a certain point, the elastic yield point. Materials store energy through deformation, and the elastic region is the zone where deformation caused by th... | [
"Pretty much. Each load cycle partially causes some plastic yield, which is to say it permanently deforms the material to some degree. Over time those small deformations add us to visible deformation. ",
"It is absolutely true that theoretical is rarely actual; theoretical is like simplified actual to get “close ... | [
"The term elastic refers to a material that can deform and return to its original shape. Even though we call many thing elastic, they aren’t perfectly elastic. When things like rubber bands stretch, they go almost back to their original shape each time, with slightly more and more permanent deformation with each us... |
[
"If everyone stayed in their house for a week, would we wipe out the common cold?"
] | [
false
] | I've been sick, recently, so I've had a lot of time to ponder this, and it seems to make sense unless there's something I don't know about disease propagation, which is likely. If everyone stays separated for a while and whoever has a cold just lets it run its course, the virus has no where else to go to and just dies ... | [
"These answers are on point. Pre-symptomatic shedding and dormant infectious agents would reduce the efficacy of an universal quarantine."
] | [
"Not my field, but what I can recall from Microbiology:\nWith the beginning of an infection (viral or bacterial), symptoms are not evident even though the infectious agent might be present and/or replicating. While the symptoms might be gone at the end of an illness, the virus within the organism might still be pre... | [
"wear it prophylactically."
] |
[
"do viruses from 30 years ago exist? for example flu strains, or the first variant of covid?"
] | [
false
] | Does the first variant of covid still exist? I ask because no one seems to be tested for it in my country anymore. Secondly, do viruses from 100 years ago still exist? Did they disappear naturally? | [
"Depends on the virus really, but in general terms they stick around a lot shorter time than their hosts. Specific strains even less so. Alpha Covid likely has as a few infections still around but it's nearly gone: ",
"https://ourworldindata.org/grapher/covid-variants-area?country=~GBR",
"Categorizing virus lik... | [
"We still have measles, mumps, chicken pox, plague, rabies, etc. Yes they continue, but they also mutate to some degree. And some just pribably just die out or mutate into less virolent strains, like spanish flu of the 19- teens."
] | [
"Minor correction, bubonic plague is caused by the bacteria Yersinia pestis"
] |
[
"Is there an evolutionary reason we associate \"savoury\" to glutamate?"
] | [
false
] | To my knowledge, we do not associate a fundamental taste (sweet, sour, astringent, etc.) to any other amino acid. Is there an evolutionary reason why we detect the presence of glutamate (and its various salt/acid forms) in food as "savoury"? Is it possible that humans evolved the ability to detect glutamate as a way to... | [
"This is a link and exert from an article in WIRED Science, which sites articles in Neuron:",
"http://www.cell.com/neuron/abstract/S0896-6273(08)00119-0",
"\nand \nJournal of Neuroscience: ",
"http://www.jneurosci.org/content/31/25/9101.short?rss=1",
"http://www.wired.com/2011/06/why-do-we-like-the-taste-of... | [
"This question got me curious, so I looked around pubmed for a bit. I found This article: ",
"http://www.jbc.org/content/193/1/23.full.pdf",
"It should be open access. ",
"In this paper the researchers measure the amino acid content of raw and cooked meat from various sources (chuck, flank, neck, plate, rib, ... | [
"Studies like this are what gets me wondering. If ever there was an amino acid that could be used to mark edible and nutritious food, glutamic acid seems to be a good fit.",
"But it also sounds like there's very little study into the why, where as a lot of research has gone into the how."
] |
[
"Is it unethical to clone and genetically alter Lonesome George, the last turle of his kind?"
] | [
false
] | Lonesome George (Spanish: Solitario Jorge) is the last known individual of the Pinta Island tortoise (Chelonoidis nigra abingdoni), which is one of eight to fifteen extant subspecies of Galápagos tortoise, all of which are native to the Galápagos Islands. Why can't he be cloned to solve this problem? | [
"http://www.reddit.com/r/ethics",
" ?"
] | [
"There is no Yes/No answer. If you think that cloning is an important advance in technology and should be heavily funded then it's Yes. If you thing that Cloning is somewhat of a grey area and there are as many different theories and specualtions as there are speices to clone then It's a no. Cloning at the moment e... | [
"As I understand it, it is incredibly hard for a clone to be made from one surviving animal. If this could be somehow done, it would be even harder for the DNA to be altered and the proteins to be added at the right embryonic stage to produce a gender opposite to the one the DNA originated from (in this case male).... |
[
"Can a person die from placebo effect?"
] | [
false
] | Let's say you give a person a fake pill and tell this person that it will start having some symptoms and then will start to "shut down", could he die? | [
"That would technically be a nocebo effect, but there seem to have been some reported cases, mostly in rural areas where witchdoctors are held in high regard. They would put a hex on a believer, and the believer would become so scared and frightened, that the emontional stress were enough to give physiological symp... | [
"There is a recorded incident in the US Civil War in which a person was shot and died - however, it turns out that the bullet missed, so the person wasn't actually shot, they just thought they were and died. \nBut then you get to the reliability of historical documents, which is a whole different discussion. "
] | [
"No, any awareness of what's going on would ruin it. Your body has many failsafes to prevent it from killing itself. For example, you can't hold your breath to death; you would pass out and control would be given to the autonomous nervous system to make sure you start breathing again. The voodoo death is a freak ca... |
[
"Does your body burn more energy when exposed to higher temperature and humidity?"
] | [
false
] | I know there are a lot of potential variables to running, given a steady pace with consistent hydration, would a person burn more energy with hot conditions and increased humidity as opposed to a drier, cooler day. Is it better for me to run at night when it is cooler, or better to run during the hot part of the day? ... | [
"I asked this before on here and a contributor said that running in the heat actually burns less calories because the mechanism for cooling is much more passive than the mechanism for heating which uses a large amount more energy. He even went as far as to say that because of that running in 115 degree weather like... | [
"I answer this assuming no period of acclimatisation/acclimation. That changes things.",
"The answer is a little complicated, but from a practical perspective, no you will not burn more energy. Exercise in the heat results in lots of changes but common observations are reductions in maximal power output, and earl... | [
"No problems - if you PM me with whats going over your head I'll do my best to explain it better. \nI'm not really in a position to comment on the effect of carbohydrate on the CNS, it's not an area I'm particularly involved in. I can tell you that recent research has shown that ingestion of carbohydrate can increa... |
[
"Why does clothing go darker when it gets wet?"
] | [
false
] | I saw a thread in askreddit a few months ago where it derailed and ended up with this question being asked, and the answers they gave were fairly interesting. I was wondering what askscience had to say on the matter. | [
"A wet cloth looks darker because less light is reflected from a wet cloth. Any cloth is woven from a yarn or fibre. That fibre is in turn made of smaller micro-fibres. Light comes from the room lights, or from the Sun, and lands on the cloth. Some of the photons of light are absorbed, but some are reflected and la... | [
"ever taken an ice cube straight out of the freezer and watched it melt? did you notice how it starts to become more transparent as a thin film of liquid water forms on the surface?",
"for the ice cube, it comes fresh out of the freezer with a bunch of surface defects--scratches, etc.--and as the ice turns into w... | [
"I think \"bending away the light\" is not the right way to describe it.",
"Total internal reflection",
" is the main effect here. ",
"A layer of water will allow light to enter, but after the light gets reflected from the cloth, trying to cross the border between water (optical dense) and air (less dense) pa... |
[
"Why can we sometimes cancel second order differentials?"
] | [
false
] | I'm an engineering student, and sometimes in class the professor will be deriving a formula or equation for something and at one point he will end up with something like dx and he will say that we can exclude that term, since it's a second order differential. Why and when can we do that? | [
"I'm honestly a bit surprised that naive differentials are used in engineering classes. Not that they are bad per se, the notation is certainly used when talking about vector fields and manifolds, and it is arguably an intuitive notion, but the context in which they are frequently used in science and engineering cl... | [
"I don't mind it much because it is a mnemonic that can be made rigorous. I guess my surprise was more that educators don't jump on the linear approximation or Taylor series approach more (or they do, I wouldn't know since I don't teach engineering classes beyond the calculus and differential equations sequence).",... | [
"That \"dx\" is something you can manipulate like a number, cancel out, multiply etc. Some of these ideas are formalized as ",
"Dual Numbers",
", but it would be more helpful to actually understand differentials than to use a naive notion of dual numbers."
] |
[
"If someone didn't know how old they were, is there a way to find out? If so, how accurate can we get?"
] | [
false
] | I know epiphyseal plate fusion can give pretty good rough estimates, especially for younger people....but beyond that...is there a way to tell how old someone is from their blood, DNA, hair....etc...? | [
"In adults, the most accurate indicators of age are the pubic symphysis of the pubic bone, the auricular surface of the ilium, and the sternal end of the fourth rib. In addition, the general condition of the skeleton, such as presence of arthritis, lipping of the vertebral bodies or osteoporosis can be used for gen... | [
"I mean a living individual. It would be hard to judge those bone indicators through radiographic images, right?"
] | [
"Not only that, but between different parts of the same individual's body, as different cells could have divided different numbers of times!"
] |
[
"Do car phone chargers draw energy with the phone unplugged?"
] | [
false
] | Although my new car doesn't have any fancy USB ports, it does have a common cigarette lighter, so I can use a conventional car charger for my phone. If I were to leave the charger plugged into the cigarette lighter with my phone unplugged, would the charger continue to draw energy? A quick Google search was inconclusi... | [
"I do this, usually no problem, but I left one in on a two week trip and came home to a dead battery. My experience is that it's ok daily; take it out if storing your car or going on a trip."
] | [
"Speculation here, I'm not a cell phone charger engineer. Your charger has a circuit in it that converts the 12 volts from the cig lighter into 5 volts (or whatever) that your phone needs to charge. The circuit details vary from charger to charger, but generally the process is not perfectly efficient, meaning the... | [
"The device will draw power even when the USB portion is unplugged because the circuitry inside is complex and presents a load even when no phone is present. It's rare to find modern electronics that draw zero current when not in use but still plugged in by virtue of modern design constraints."
] |
[
"Is there perhaps a biological reason little kids like sugar so much?"
] | [
false
] | Sugar is addictive. We all love it. But we tend to grow out of eating pure sugar (eg candy) as we reach adulthood. Could it be something about kids' developing biology that makes them LOVE sugar? Or is it just that younger children have poorer impulse control? | [
"Children do have more taste buds and are more sensitive to tastes. As infants, we tend to be most sensitive to sweet and bitter tastes, developing saltiness later. Many plants that may be harmful to us come across as bitter and perhaps this drove the evolution. Higher caloric foods (such as breast milk) tend to ha... | [
"In a related note, I've heard in my neuroscience classes that the higher sensitivity to bitter tastes is possibly the reason kids don't like to eat vegetables. "
] | [
"I always thought it was just cooking style, I've never heard of Asian, Indian, Middle-Eastern kids recoil in such horror at veggies like White American and Black American kids. The difference being veggies cooked and mixed within foods with flavor as opposed to simply steamed and served. Could be a confirmation bi... |
[
"How does a cell \"know\" where to position it's self in the body."
] | [
false
] | This is very hard for to to try to explain, but for example when a lizard's tail is cut off, how do the stem cells "move" in the position of the tail. | [
"Generally, development follows the direction of ",
"morphogens",
", biological signals that form a gradient that cells use to determine where to migrate.",
"Interestingly, a famous one is named ",
"Sonic Hedgehog",
", from those heady days when gene naming was less...",
"."
] | [
"Signaling is the general answer here, as mentioned by other posts already. ",
"Each cell contains all the genetic information needed to become any cell of the body, but it requires certain triggers/signals to express certain genes, i.e., to \"become\" different kinds of advanced cells. A cell usually receives a ... | [
"We actually published a story in Cancer Research a few years ago linking Indian Hedgehog signaling to bone metastatic breast cancer. Anecdotes aside, there are several studies linking the abrogation or deregulation of similar pathways to cancer progression. "
] |
[
"Do people with more active brains burn more calories?"
] | [
false
] | null | [
"I can only provide a theoretical answer for this based upon my knowledge of fitness and personal experience. The brain consumes more calories than any other organ but it still consumes much less energy than our combined muscle mass. During a rigorous mental workout the body draws energy away from the muscles and u... | [
"I think it's perfectly reasonable to assume so because the brain consumes more calories than any other organ. "
] | [
"This may sound ridiculous, but would it then be possible to lose weight by \"thinking harder\" or something? i.e. if someone is doing complex math problems all day, they'll have a slightly higher daily calorie budget than if they were to just sit on the couch looking at cat pictures."
] |
[
"In bee colonies, why are female worker bees unable to lay eggs? where/how did they lose their ability, and how do new queens emerge?"
] | [
false
] | Kinda got me confused; if the queen is the only bee that can lay eggs, if the queen dies, does the entire colony die off? | [
"I'm not actually entirely sure they can't lay eggs (or at least I'm not sure that it's the case for all species of bee) but in the case where they cannot lay eggs it's not that they lose the ability, it's that they never gained the ability. To answer both of your questions:",
"http://en.wikipedia.org/wiki/Queen_... | [
"Well there you go, question answered! Also, I ",
" end up reading more into it, and its interesting how females are diploid but males are haploid in chromosome count (fertilized vs unfertilized).",
"Royal Jelly, huh? Thats a neat way of preventing 'uprisings' from other potential females. Bees just got a whole... | [
"On the uprising bit: not really true at all. The queen doesnt really have a say in whether or not a new queen is to be prepared. Her perssonal worker bees that tend the eggs decide whether or not to start preparation. For example when queen bees in honey farms start getting old the beekeper will clip one of its hi... |
[
"What is the best method to solve cubic equations?"
] | [
false
] | What is the best and more quick way to solve an cubic equation? Is the Algebric method or a numerical method? | [
"There is an exact formula for the roots of a quartic, but it can be pretty cumbersome. For polynomials of degree higher than 4, there is no general formula for the roots. "
] | [
"An algebraic method actually solves it, a numerical method just approximates it. So if you want an exact solution, you have to use an algebraic method, eg ",
"Cardano's Formula",
". If all you need is a \"close enough\" answer, then numerical methods are fine."
] | [
"There is a general solution to quintic polynomials.",
" It's just necessarily expressed in terms of transcendental functions."
] |
[
"Why do plant cells not die of \"old age?\""
] | [
false
] | null | [
"Do any individual plant or animal cells actually die of old age?",
"I am sure some ",
"single cell bacteria can live for millennia",
", and what would it mean to die for an organism that reproduces by cell division?"
] | [
"Because genetics aren't all there is when it comes to aging. Some parts of the body simply don't heal very well. Things wear out and break, scar tissue accumulates in the place of healthy tissue, exc.",
"Even in the case or organisms that possess regenerative abilities healing isn't perfect.",
"Crabs with a da... | [
"Who says they don't? The lifespan of a plant cell will vary by species and environmental conditions, but they cant live forever.",
"An oak tree might be hundreds of years old, but its cells aren't. The only parts of wood that are made of living cells are the layers just under the bark. The cells of both the bark... |
[
"Is there any reason to suspect or way to find out if COVID-19 could cause adverse side effects long term after recovery?"
] | [
false
] | [deleted] | [
"We simply don’t know yet. In general this virus kills through complications (compounds other health problems, increased chance of pneumonia etc). It might be hard to tell if the virus, or others things will cause long term damage."
] | [
"Whilst this is true it is worth noting that lots of things cause lingering lung damage. Smoking being the most obvious, but living near a highway or in a city, living in humid atmosphere with household mould spores, cooking on wood or coal fires., etc.",
"This is not to diminish the potential severity of Covid, ... | [
"Whilst this is true it is worth noting that lots of things cause lingering lung damage. Smoking being the most obvious, but living near a highway or in a city, living in humid atmosphere with household mould spores, cooking on wood or coal fires., etc.",
"This is not to diminish the potential severity of Covid, ... |
[
"Are there any animals that do not have significant differences between the sexes besides reproductive organs? Are there any social animals without gender-based social roles?"
] | [
false
] | Sorry about the two-part question. With all the talk the last few decades about gender and sex equality, you often hear people argue that men and women are not different in any significant way beyond what is biologically necessary for reproduction. People often say that women and men are innately equally capable at all... | [
"I'm wondering if there are other species that fulfill this vision. ",
"There are species that fulfill that vision, but humans are probably not one of them.",
"\nSexual dimorphism in humans is very obvious. Males are larger, grow hair on their faces, have a different shaped body to females, and as it turns ou... | [
"Thanks a lot for the reply and the links. All very informative. "
] | [
"I was about to say I'm not sure. ",
"I know the answer for parrots and they have the same circumstances. They mate for life (ish) and they have a reasonably equal parental investment. In birds the parental differences in investment in species with mutual parental care is going to come down to the gamete. So t... |
[
"Why do neutrons embrittle material?"
] | [
false
] | null | [
"Good question! The short answer is that it damages the crystal structure of metals/ceramics/whatever, causing more errors in the crystal structure, which allow cracks to form more easiy and it breaks.",
"The long answer is that it's the same process as \"cold working.\" When you bend a paperclip back and forth, ... | [
"Sure! ",
"Although a slight clarification, I meant to say that dislocations make it harder for other dislocations to ",
". ",
"Imagine you have a big single crystal of quartz with a perfect crystal structure. If you imagine a dislocation diffusing through a perfect structure, it's gonna move through really e... | [
"Sorry for my clumsiness, but can you explain the dislocation making dislocations harder to form part in more detail?"
] |
[
"How tall would a wind tunnel need to be to safely land a human jumping from a plane?"
] | [
false
] | You know those wind tunnels that people do indoor skydiving on? Let's assume for a moment that you can build one of those as tall as you want, and be able to provide the same amount of wind throughout the entire length of it. Assuming a 175 lb man jumps from a plane at 10,000 ft with no parachute, and is able to guide... | [
"It depends on how much deceleration you can handle. You have to decelerate from 50 something meters per second to 0. Plug in your deceleration rate, it will give you the time it will take and the distance (the length of your wind tunnel) you will travel."
] | [
"a typical human can withstand 5g's. terminal velocity of human is around 120miles an hour(53.64m/s). it takes around 24meters to decelerate from 53.64m/s to 0m/s at a rate of 5g's."
] | [
"1.1 second. 5g's=-49m/s"
] |
[
"Is there research on the mental health effects of virtual windows on workers in confined, windowless spaces for long time periods?"
] | [
false
] | When discussing topics like space exploration, underwater colonization, or even just the future of dense urban living and working, it often gets brought up that people may go insane from being subject to windowless conditions for too long. It seems like virtual windows (high-quality displays masquerading as windows to ... | [
"Most laboratories I've worked in don't have windows. Also libraries limit their windows and can be very dark working in the stacks. \nThose intentionally windowless buildings are not for a \"bad physiological nature\" but definitely a necessity as a lot of science and preservation of books are sensitive to light."... | [
"The majority of places that don't have windows are Warehouses my friend, where tens of thousands of Americans works every day. There may be some places that can't have windows, but most places do it as a cost saving measure, to both save on installation and energy bills."
] | [
"The problem with this is that most of the time, if a building has no windows, it is doing an intended purpose of a bad physiological nature. The people you would market it to would not care. There's a movie called War Dogs, a line in it that explains it well. Why would I wrap a lizard in a cashmere sweater? That's... |
[
"What is the functional difference between fibroblasts and fibrocytes?"
] | [
false
] | Everything I’m reading online says they’re different but fails to really explain how. The functions seem really similar (e.g. fibroblasts are characterized by synthesis of proteins of the fibrous matrix, whereas fibrocytes produce connective tissue proteins such as vimentin and collagens I and III) - if they’re both sy... | [
"This is a complex question. Have you read ",
"this, the paper that first defined fibrocytes",
"? Although the unique secretion functions and lineage of fibrocytes are still being investigated, some researchers are still defining them by those hematopoietic and leukocyte surface markers CD34 and CD45, respectiv... | [
"I think that most specific and useful way of naming cells would be by their markers (clusters of differentiation - CD). \nNames that we give them (like fibroblasts, etc.) are there for basic understanding of their functions and can differ between individuals. Think of the mess that is naming a macrophage in differ... | [
"Thank you so much! "
] |
[
"If low and high frequency waves like radio waves or x-rays can both penetrate barriers (like clothing or flesh), why can't visible light do this?"
] | [
false
] | null | [
"Another way to think about this is that visible light does penetrate plenty of things that are opaque to other frequencies. For example, glass is extremely transparent in the visible frequencies, but opaque to infrared (lower frequency) and ultraviolet light (higher frequency). When we think about things as tran... | [
"You don't get sunburned in your car in the same way you get sunburned out in the park. UVA penetrates glass and (amonst other things) causes skin ageing, whereas much of the UVB gets reflected. It's UVB that causes sunburn in the more traditional sense."
] | [
"Fair enough. I guess my point is that in a standard spectroscopy set-up, you're comparing the light lost as it passes through your sample, which includes both the light which is absorbed, and the light which fails to reach the detector because it is scattered. When dealing with the question of why certain materi... |
[
"When the wind blows, do the individual air molecules actually travel as fast as the wind?"
] | [
false
] | How fast do air molecules actually move? It seems like they're so incredibly small that they would have to be moving at relativistic speeds to get anywhere. | [
"It seems like they're so incredibly small that they would have to be moving at relativistic speeds to get anywhere.",
"What? Speed means you travel x distance in y time, it doesn't have anything to do with how big a thing is."
] | [
"No. They travel way faster, in random motions. At room temperature, they move at about 500 m/s. ",
"Interestingly, as it gets colder, they move slower also. Scientists who are studying temperatures near absolute zero are also getting more of a glimpse of the atom, since it moves slowly... ",
"\"For instance, w... | [
"This is true, but remember that the mean free path of air molecules is around the order of 10",
" m (at STP). This means the gas will be characterized by a viscous flow (the wind) and can be treated as a \"fluid\". So yes, over distances larger than a few microns, on average, they all move with the wind speed.... |
[
"Why does semantic satiation occur?"
] | [
false
] | null | [
"Your link only points to Wikipedia and a Google search which contains only this post."
] | [
"Thanks for the suggestion, but Reddit's search is not bringing up many posts either."
] | [
"See this listing in sciencefaqs",
"."
] |
[
"Can we simulate what is happening inside of a black hole?"
] | [
false
] | I'm having an argument with my friend on whether or not it would be possible to use a computer to simulate the environment beyond the event horizon of a black hole. I believe it can't be done because physics breaks down inside of a black hole and modern physics wouldn't have enough information to run a simulation like ... | [
"Yes. And some heavy-hitters in physics make a living doing it. ",
"A black hole has a \"boundary surface\" we call the event horizon, but it isn't a physical thing, it's just a boundary we agree is useful to recognize, like the border between nations. Outside the event horizon, a beam of light light ",
" escap... | [
"If you do simulate a universe, you would just treat black holes as their own objects. You wouldn't simulate the inside of them. ",
"To answer your question, no we can't simulate the inside of black holes without guessing. "
] | [
"Exactly, which is why I said we couldn't do it without guessing. Given the current laws of physics, it's absolutely unverifiable. "
] |
[
"How does the JWST slow down to stop in the L2?"
] | [
false
] | Title sorry that's all I got. Couldn't google anything that comprehended my understanding. Please link any articles if you have any. Would love to read up on this particular part of the JWST operation. Also sorry if I don't respond immediately. Just worked a 13 hour shift and got another 11 hour shift tmrw. Need some s... | [
"There are a couple of older threads about its trajectory. The gravity of Earth and Sun slow it down, it will arrive in the L2 area with almost zero speed and then make a course correction maneuver to enter its target orbit.",
"The rocket launched it a little bit too slow to reach L2, then JWST sped up using its ... | [
"No, after 10-12 years it will just run out of fuel and become unable to operate and reposition - unless someone figures out a way to refuel it and doing that is deemed worth it. A refuel is not part of the current mission design because of how difficult it would be to pull off so far out.",
"Without fuel it woul... | [
"JWST has thrusters on it. Most of the work has been done already; it's coasting \"uphill\" now, slowing down as it goes. It won't stop right at L2. The coasting arc it's on will put it off to one side, and at the right time the thrusters will be used to nudge it into some flavor of a \"halo\" orbit. It will ha... |
[
"How do you build large structures in violent water?"
] | [
false
] | null | [
"It doesn't. but it can keep it from forming large 'chunks'",
"Imagine concrete as water freezing. If you let it sit in an ice-cube tray, it starts to freeze on the surface or along a rough spot and forms a larger and larger frozen area.",
"If you freeze water in a slushie machine, the particles don't really ge... | [
"Concrete actually hardens better underwater, in many conditions."
] | [
"Well that's really fucking neat. Now I got to go read up on concrete. "
] |
[
"Other than making profits, what is stopping vaccine makers such as Pfizer and Oxford from simply sharing their vaccine patents?"
] | [
false
] | Would there be a way for government to require them to share their patents with less successful biotech companies? | [
"The challenge is the FDA clearance is tied to manufacturing sites and other regulatory issues. Each manufacturer has to have fairly extensive testing done before they are allowed to release drug product to the public. All this testing takes time and is very particular, a set of standards generally known as GMP (... | [
"Also, a huge thing people forget is that most vaccine candidates started being produced the moment they were conceived. The vaccines we're getting now are the result of massive investments in facilities for a vaccine that may never be approved. ",
"If they made their process public, it would still take 6 months ... | [
"The Oxford vaccine is not yet FDA approved at any level, so even with open source technology, in the US anyway it can’t be administered. And again, even if the instructions are open sourced, each company that would want to manufacture it still must follow GMP protocols, and that takes additional regulatory cleara... |
[
"Did the construction of the LIGO gravitational wave detector account for the curve of the earth? Did each end of have to be risen up a bit so that each light beam was perfectly straight?"
] | [
false
] | Title | [
"From ",
"one LIGO's own web pages",
" w/various LIGO facts :",
"Curvature of the Earth: LIGO’s arms are so long that the curvature of the Earth is a measurable 1 meter (vertical) over the 4 km length of each arm. The most precise concrete pouring and leveling imaginable was required to counteract this curv... | [
"Your math ",
"checks out",
". There are many, many corrections that had to be made to LIGO to get it to the accuracy and precision they needed. Still, it’s extremely noisy. They have to run lots of processing and filtering routines to be able to focus on the signal of gravity waves specifically. "
] | [
"Some back of the napkin math tells me that at 2.485 miles long and the curvature of the earth being 7.98 inches per mile",
" mean that 7.98* 2.485",
" =49.3 inches. Assuming the center of the detector is level and the two detectors must be raised up that means their heights must each be raised 24.965 inches.",... |
[
"Why is there such intense radiation around Jupiter?"
] | [
false
] | From what I understand, Juno is about to get slammed with radiation which will slowly take out its instruments. What is the source and nature of this radiation? How would a human visiting Europa or Titan be able to withstand it? | [
"Titan is a satellite of ",
".",
"Jupiter has a massive magnetosphere, both in intensity and size. Solar wind (which is radiation composed of charged particles) is unable to penetrate it.",
"Primarily, the radiation around Jupiter comes instead from gases from its innermost moon Io, which has intense volcanic... | [
"the radiation does not flow from Jupiter out, it rotates rigidly with Jupiter. So maybe a better idea is to on the backwards-facing side, not the Jupiter-facing side. But I don't know how much that would help.",
"Europa has an induced magnetic field, probably from the water ocean, that might affect the path of r... | [
"Callisto is actually safer than Earth in terms of its level of radiation exposure",
"Not really. It's safer than the Moon and safer than the ISS, but here on the surface we're further protected by the atmosphere which is a pretty good shield.",
"On Callisto it's about 0.1 mSv/day (36 mSv/year), while on Earth ... |
[
"Where do bugs live during the 'off season' where there aren't many to be found?"
] | [
false
] | If anyone lives in Florida or is familiar with Florida, a few weeks out of the year swarms of lovebugs are everywhere. They seem to be a lot flying near the roads so they mess up the car as you drive. But after these few weeks, I don't see any of them the rest of the entire year. Where do they go? | [
"The answers will be as varied as the number of species, but in general arthropods go through multiple physical forms over the course of their life cycle. In the case of love bugs, they're spending a lot of time as eggs and then larvae feeding on grass and leaves; the swarms you see for a few weeks at a time are th... | [
"Apparently, most die and their larva are seeded in moist soils.",
"http://insects.tamu.edu/extension/publications/epubs/eee_00025.cfm",
" "
] | [
"Also, many insects undergo a physiological state of dormancy called ",
"diapause",
". All though it can take many forms, an example would be that a freshly hatched butterfly larva at the end of the summer would burrow into the soil near the roots of it's host plant and become dormant over winter, emerging agai... |
[
"How does the absorption of radiation lead to an increase in temperature?"
] | [
false
] | When a photon is absorbed by an atom, it becomes excited and an electron is moved to a higher energy level. How does this translate to an increase in the atom's kinetic energy if the energy is used to move the electron further from the nucleus? | [
"The other comments get the gist right in that the answer is conservation of momentum. However, the story is slightly more complicated because unless you are in a very specific regime of stimulated emission, the atom will on average not move. The excited atom will randomly emit in any direction, so the average chan... | [
"Perhaps this is easiest to understand with conservation of momentum (this is applying a classical principle to a quantum process, but it's just to give you some intution)",
"Photos have energy, E = hf, but special relativity tells us for photon E = pc, so we can actually get a momentum for a photon. Then when th... | [
"The excited atom will randomly emit in any direction, so the average change in momentum of the atom is actually zero! ",
"From the emission yes, but not from the absorption. This is used e.g. in laser cooling where the lasers are tuned to be absorbed by approaching atoms only, so the absorption slows them down."... |
[
"Would it be possible to detect signs of life/civilization on a earth-like planet 500 light years away?"
] | [
false
] | null | [
"The only way I could conceive of would be intercepting a patterned signal that might indicate intentional EM emissions. See the ",
"Wow! Signal",
" for a potential example.",
"Nothing would be confirmed by something like this, though it might warrant some deeper looking. Even if we detected something, pinp... | [
"If youre looking for methane and greenhouse gases, Venus looks like a great candidate from far away."
] | [
"The Wow! signal only lasted 72 seconds, so it's not a case of an alien civilization dying out before anything could come of their work. The fact that it hasn't repeated again suggests that it wasn't extra-terrestrial in origin. Here's a good XKCD what-if on a related topic.",
"http://what-if.xkcd.com/47/",
"Al... |
[
"What exactly is responsible for developing speed of our muscles?"
] | [
false
] | For example professional metal drummers - all I know is that by a lot of training they can achieve ridiculous drumming speeds. But what exactly in their training makes their muscles able to contract faster and faster as they become more skilled at it? Can someone provide a biological explanation? Thanks! | [
"Many mammals consist of two types of muscle. They have red muscles(slow twitch muscles) which habe the ability to perform long, heavy , sustained amounts of work and white muscles(fast twitch) which are known for performing minimal work in fast bursts of speed.By performing repetitive, fast actions, in this exampl... | [
"Incidentally, this is why chicken breast is \"white meat\" and the legs are \"dark meat\". The leg muscles are optimized for sustained activity, and the wing muscles for short, intense bursts of activity in chickens. The breast muscles of ducks, which are long distance fliers, has a much higher percentage of slo... | [
"Can the white muscles grow in size? "
] |
[
"Does drinking carbonation affect your oxygen intake?"
] | [
false
] | I have read and been told many different things on this subject. Some say that the carbon dioxide will attach to your blood, thus allowing less oxygen to get to where it needs to go. Others say the negative effects of drinking carbonation come from the soda that goes along with it. Another question I have would then be... | [
"Short answer:\nCarbonated drinks have no significant effect upon your blood oxygen levels. The level of sodium in these drinks is not enough to be a significant health concern compared to other dietary sources of sodium (salty foods). ",
"Long answer: \nAll water that you drink has carbon dioxide dissolved into ... | [
"I can think of no reason why this would occur. A quick search of the literature doesn't give any indication of this either. "
] | [
"What about carbonation's effect on breath capacity in the short term? I'm an instrumentalist and have always been told not to drink a carbonated beverage prior to a performance because it diminishes the ability to take a deep breath. Is this accurate? The only reason I can fathom is that one would be afraid to ... |
[
"If I travel to a planet 40 light years away from earth at the speed of light how will time pass differently for me in comparison to people on earth?"
] | [
false
] | null | [
"About 6 years. That is assuming it is 40 light-years away from the perspective of somebody stationary on Earth. ",
"From your perspective",
" the planet is ",
"5.6 light years",
" away and moving towards you at 99% the speed of light. So that is actually 5.7 years."
] | [
"You can't travel at the speed of light (hence i used 99% as an example). ",
"The other point is that there is no unique rest frame. To somebody stationary relative to you (and the planet you are heading towards) your clock runs slow (meaning anything that could conceivably be used to measure time) and it takes 4... | [
"What do you mean moving towards you? In order for time dilation to occur it would have to be the hypothetical ship going at the speed of light right? Thank you for your answer."
] |
[
"If you went up into open space with a jar, closed the lid, then came back down to earth, what would be in the jar?"
] | [
false
] | Let's assume a few things: that the jar is of a super strong material (not glass), that the seal when the jar is closed is super tight, and that the jar had been open upon going into space | [
"Something very close to a vacuum."
] | [
"A very cursory glace at Wikipedia shows that the pressure at the \"Karman Line\", which is sometimes considered as the boundary between outer space and the atmosphere, is about 2.4E-4 Torr. So an O-ring should suffice near this area :)"
] | [
"A very cursory glace at Wikipedia shows that the pressure at the \"Karman Line\", which is sometimes considered as the boundary between outer space and the atmosphere, is about 2.4E-4 Torr. So an O-ring should suffice near this area :)"
] |
[
"Why do cats break stuff? I’m not talking about curiously checking something out, I mean those times where it feels like they just want to be jerks?"
] | [
false
] | So I just saw this video: And look at it! The a**wipe knows it’s gonna fall. And I’ve seen many similar stories/videos. Are they confusing cups and dishes for...prey? Do they like the noise when it shatters? What is it? Why? With dogs they chew a lot of stuff coz they just wanna eat all the time and are curious if it’s... | [
"They’re not being jerks. Cats don’t think like that. They either crave some kind of attention (even if it’s negative it’s better than being ignored) or they’re bored. Cats are a lot less work than dogs, but if you don’t play with your cat(with cat toys, or a laser pointer), they’re going to find some way to expend... | [
"In my observation, cats resent anything their owner spends too much time with, especially if we touch it a lot. I'm a bookworm, and twice I've had cats who pull books off shelves. If I write something and leave the papers on my desk, I wake up to them shredding them. I think they think I'm \"petting\" a ri... | [
"I have two cats, and one of them, when he gets the zoomies or when he gets bored at night while I'm sleeping.. He leaves death (plants) and destruction (furniture, papers, books, glasses, decorations, anything!) in his wake, he wreaks havoc like he's evil incarnate. I still love him though. He's not even a year ol... |
[
"Is there a set distance between stars when they are no longer considered a binary/trinary/multiple star system?"
] | [
false
] | Are there any star systems that come close to deciding whether the system is truly a multiple star system? And if so, what criteria is required to be considered as such? | [
"Stars in a multiple star system are bound together by gravitational attraction and orbit a shared center of mass. If these circumstances don't exist, they aren't a system as such. Distance is certainly a factor, but not the only one, in if the gravitational attraction is stable and sufficient. "
] | [
"Or a small object on a hyperbolic trajectory when it is very far from the other object."
] | [
"If the trajectory is hyperbolic then it doesn't count as a multibody system, since they're not bound together."
] |
[
"Does anyone know a reputable study that measures the tar content of vaporized cannabis and/or compares the tar content of vapor from different vaporizers?"
] | [
false
] | null | [
"I found ",
"this",
" which shows surprisingly different results. "
] | [
"or tar content of vapor compared to tar content of other forms of cannabis inhalation "
] | [
" upvote for finding an answer."
] |
[
"Why aren’t different dog breeds considered different species?"
] | [
false
] | [deleted] | [
"There are a lot of different ways to describe taxonomies and species. ",
"For instance, you are describing a ",
" concept which bases species based on phenotype or how something looks (an inaccurate manner of doing so.) The ",
" takes a step further and determines separate species by asking, “Can they mate a... | [
"Viable offspring seems to be more of a rule of thumb than a law when it comes to nomenclature.",
"Yes, that is correct. Taxonomy depends on which concept you utilize (phenotypic versus biological). Because natural selection is dynamic and species are constantly between diverging and converging, it’s not easy to ... | [
"Viable offspring seems to be more of a rule of thumb than a law when it comes to nomenclature.",
"Yes, that is correct. Taxonomy depends on which concept you utilize (phenotypic versus biological). Because natural selection is dynamic and species are constantly between diverging and converging, it’s not easy to ... |
[
"Why doesn't lightning travel at the speed of light."
] | [
false
] | I've seen several videos where the formation of a lightning bolt has been captured by a high speed camera. It must be going significantly slower than the speed of light for this to be possible. Why? | [
"Photons travel at the speed of light i.e the light entering your eyes from the lightning bolt. The actual particles travelling through the lightning bolt is electrons and they don't travel at the speed of light, like electrons in a circuit. Simply put, electrons have mass and therefore they can't travel at the spe... | [
"What’s happening is the ionization of air by high‐voltage electricity. It starts at the clouds and makes a path to the ground. The ionization propagates quickly, but at nowhere near the speed of light.",
"You may be confused by the folk‐wisdom of measuring the difference in time between seeing the light and hear... | [
"Because electrons and ions have mass."
] |
[
"What is the difference between the gas types at the pump?"
] | [
false
] | null | [
"This is a half-truth. When we are talking about gas/petrol, \"Octane rating\" of fuel is a measure of how the fuel behaves when it is compressed. It is called \"Octane\", because the chemical octane is used as a benchmark for comparison. The octane rating can give some indication of a fuel's octane content, but... | [
"This guy has it right. You should only fill a tank with what the vehicle recommends, otherwise you're wasting money. A lot of high grade gasolines contain extra detergents to help clean your engine, but the money you save on lower octane gas will more than cover over the counter additives you can add to your tank.... | [
"Gas is make up of a mix of various hydrocarbons, and octane is one of them. What makes octane special is that it can be compressed to higher pressures without spontaneously combusting. In your average engine, this doesn't matter too much, so get the cheap stuff, but in some high-performance engines, the compress... |
[
"Why is it that men's sperm need to be at a lower temperature, while women's eggs are ok at body temperature?"
] | [
false
] | null | [
"As sperm develop, they are metabolically inactive. During spermatogenesis sperm lose nearly all their organelles and are dependent on Sertoli cells for protein synthesis and other functions. It is only after ejaculation that swimming activity is triggered presumably due to other components in semen. So the decreas... | [
"The process to form sperm is called spermatogenesis. It transforms one spermatogonia (with n pairs of chromosome) into 4 sperm cells (with n single chromosomes each). The original cell undergoes meiosis to split its DNA in half.\nWhen the original cell, the spermatogonia, is at 37°C, two proteins (cyclin B1 and cd... | [
"Sperm definitely swim without being in a vagina. You can view them swimming on a microscope slide without any sort of treatment."
] |
[
"Which would be more efficient: one large fan, or several small fans?"
] | [
false
] | [deleted] | [
"One large fan. Each fan requires an axle* that needs to be spun but doesn't blow any air. ",
"One fan = one axle, many fans=many axles. ",
"It isn't as simple as that since you need a stronger/heavier axle for a larger fan. But an example is wind turbines, if many small ones were more efficient they would be m... | [
"But the large fan has much higher blade tip speed, meaning increased drag. This is why many large helicopters use multiple rotors."
] | [
"Good point, there is a practical limit on the size. But I think that even in large wind farms they still use the largest turbines possible."
] |
[
"Why aren't Technetium and Promethium naturally occurring?"
] | [
false
] | Do they undergo radioactive decay too easily? If that's the case, why them and not the elements near them on the periodic table? | [
"Note that both isotopes do occur in nature. For example, we can see ",
"technetium in stars",
". ",
"You are essentially correct about radioactive decay. All isotopes of both elements have half-lives which are too short for them to last long in nature. As for your last part of the question, it is an excellen... | [
"Tweaking my answer from ",
"an earlier time this was asked about Tc",
" (answer is same for Pm):",
"The stability of an atom is determined not just by the atom in question, but the atoms that it could decay into as well. If an atom is heavier than another one plus the mass of any emitted radiation needed to... | [
"It is when an object spends an extended period of time (vague, I know, but that's the way it is) in a state where it has extra energy. Normally nature is quick to release extra energy, but sometimes things work out such that it takes a while.",
"In the context of nuclear physics, we're usually talking about exc... |
[
"What resources can tell me if scientific studies are unbiased and peer-accepted?"
] | [
false
] | null | [
"A good home for this question would be ",
"/r/AskScienceDiscussion",
"."
] | [
"Thanks. How does ",
"/r/AskScienceDiscussion",
" work better for this discussion, or how others can know to post there rather than here?"
] | [
"Its a good place for open-ended questions like this one. Give it a try!"
] |
[
"Could you use a collection of entangled quantum pairs to create a data/telecom switching system (binary) that would allow crazy fast and unconnected worldwide communications?"
] | [
false
] | null | [
"I'm going to skirt around a robust discussion of entaglement, there are a lot of good ones on askreddit. However, importantly, information can not be transmitted faster than the speed of light (in a vacuum). Regardless of how entanglement works, I can not use that mechanism to relay a message to you faster than li... | [
"What do you mean by an unconnected network?",
"Throughput in a quantum network may well exceed what is possible in its traditional counterpart. The networks I have seen investigated use traditional methods to link nodes; wired and wireless protocols will likely be similar to what we see today. Theoretically, the... | [
"I mean, no physical connection. No wires, no optics. ",
"As for the speed of light, I was under the impression that entangled particles (is that right?) change at a speed greater than the speed of light. Or perhaps, instantaneous. "
] |
[
"How does any photon reach exactly the energy needed to excite a particular atom?"
] | [
false
] | I know that quantum mechanics states that some things, like bumping an electron to a higher energy level, requires something like a photon to have juuuuust the right energy for the electron to 'accept' that photon and then rise to the higher energy level. But it is always explained that it has to be exact. Like, E... | [
"There's a relationship between the uncertainty in the energy of an excited state and the lifetime of that state. This creates the \"natural linewidth\" of a spectral line. The fundamental broadening of a spectroscopic line that cannot be narrowed by any sort of improved spectrometer design because it's just due to... | [
"Adding to that, there are several mechanisms by which spectra are broadened. For example, the fact that atoms and molecules are moving at high speeds in most instances allows them to interact with light at different wavelengths because of the Doppler effect - if the molecule/atom is moving away from the light sour... | [
"There are indeed some situations where the energy of the incoming photon should match quite exactly the energy difference between the two states. The perfect example of this is Mossbauer spectroscopy. It blew my mind when I discovered this technique and how it works.",
"The goal of Mossbauer spectroscopy is to p... |
[
"How do forces act on a rotating body when it is impossible to determine if the body is rotating or the universe around it."
] | [
false
] | Also, when looking at orbiting items around the earth. Is the speed of orbit relative to the planets rotational speed or the suns? Hope this makes some sense. Thanks | [
"Rotating and non-rotating frames are not equivalent."
] | [
"Not in point of fact, no. Acceleration is not relative. It's a literal, physical phenomenon which you can measure with an accelerometer — that is to say, a piece of equipment no more sophisticated than a mass on a spring."
] | [
"You can definitely detect whether you are in a rotating frame or not."
] |
[
"Can High-Proof Alcohol Be Used To Maintain Dental Health?"
] | [
false
] | From my understanding of dental problems, a lot of them - tooth decay, for example - are bacterial in nature. Since ethanol is an antiseptic, would it serve the same (or similar/better/worse) function as toothpaste when it comes to killing harmful oral bacteria? And if so, are there any negative side-effects (aside fro... | [
"There are many.",
"Here is one",
"http://cancerres.aacrjournals.org/content/51/11/3044.short"
] | [
"I am aware that we use 70% alcohol solutions (ethanol in H20 by weight) to sterilize surfaces. At super high proofs it would not be as effective at killing bacteria because some water is required. "
] | [
"Alcohol in mouthwash has been linked to cancer. "
] |
[
"What makes the electron shells of the atoms between Scandium and Zinc seem to go haywire, while suddenly regaining a stable outer shell increase from Gallium to Krypton? Why does this pattern repeat throughout the periods?"
] | [
false
] | null | [
"This has to do with orbital theory. Electrons are filling up d orbitals in that middle row, and electrons will always go to lowest energy configuration. Sometimes it's more favorable to fill other orbitals first and other times it's not."
] | [
"A filled or half-filled d- orbital is much more stable than if it is missing an electron, which is why you'll see that it often strips one from the s- orbital to make the d- orbital half or fully complete. ",
"This is also part of the reason for some of the complex ionization states you see especially in transit... | [
"You've fallen into the trap of thinking classically! To crash into the nucleus, you'd have to have zero momentum and a known position which is forbidden by the uncertainty principle."
] |
[
"A big ol' bleach and silver mess."
] | [
false
] | Hello Askscience, I am a bench jeweler with a problem on my hands and hoping you could give a little insight. I recently had a silver snake-chain bracelet come in that was heavily oxidized from someone trying to clean it with bleach. Our S.O.P. with heavily oxidized silver is to use a flame to remove the oxidation then... | [
"The good news is ammonia can be washed away with water."
] | [
"Silver chloride? It's terribly insoluble, white-looking stuff. ",
"The good news it dissolves in ammonia. "
] | [
"Thanks! After Googling, AgCl seems to fit.\nThe wiki article on AgCl said it is also soluble in concentrated sulfuric acid. I may just make a strong pickle on the side and try that. "
] |
[
"If you were stuck on a desert island with no potable water, would swimming in the sea hydrate you?"
] | [
false
] | null | [
"Nope, you need to drink to get hydrated as people don't efficiently absorb water through skin."
] | [
"Even if it is inefficient, could the body be hydrated by being fully immersed in water?"
] | [
"As I said - no, we don't drink through skin."
] |
[
"Is it possible for a material to have a higher density in its gaseous state than its liquid state?"
] | [
false
] | Since water has a higher density in its liquid state than its solid state (at least one of its solid states) I was wondering if the same is possible for solid/gaseous states? | [
"Not for a single given pressure. Allow me to explain why:",
"The reason ",
" solids have higher density in their solid state than their liquid state is because their ",
"natural crystal structure is less dense than their unordered liquid state",
" due to hydrogen bonding dominating the intermolecular forc... | [
"I don't think that's possible. For a material to have a high density in either of those states, either the weight of the individual molecules has to be high (think bromine or iodine), or the intramolecular forces have to be strong (like water), or both.",
"When we're talking about the same substance, just going ... | [
"The other answers are correct. I'll just add for intuition that the difference in density between a solid and liquid state for a material is roughly a few percent, while the difference between liquid and gas states is on the order of 1000x lower for the gas."
] |
[
"Absent biological and hormonal influences, how is it speculated that a conciousness \"uploaded\" to a digital medium would act."
] | [
false
] | [deleted] | [
"Sort-of answer that's really more of an addition to your question: Do we really fully understand the role of chemical and even physical factors in cognition? Can the activity of the brain even be accurately modeled by digital \"neurons\" that pass around potentials, but which have no sense of chemical environment... | [
"One would assume that the goal of \"uploading\" a mind to a computer would be that it behaved identically to the biological mind. The idea is more science fiction than anything at this point, but if it (ever) becomes a realistic possibility then I'd expect any and all factors which affect cognition to be taken int... | [
"Well as far as I understand, the wiring and rewiring of nueral pathways is the \"skeleton\" of the concious. Chemical factors, play a role as \"traffic cops\". They speed up, slow down, stop, limit, etc. the synapses and connections which the brain interprets as conciousness. The senses are just signals sent to th... |
[
"Mitchondrial membrane question: Why do the H+ ions stay in the intermembrane space instead of leaking out the outer membrane?"
] | [
false
] | So, I'm learning oxidative phosphorylation right now. Here's what I know: the respiratory chain in a mitochondria uses energy derived from NADH/FADH2 to drive a proton gradient in the intermembrane space. The inner membrane is relatively impermeable to H+ ions, so that is the electrochemical force that drives ATP-synth... | [
"AFAIK, neither of the membrane are particularly 'leaky'. There's ATP synthase as an obvious channel for protons back through the inner membrane, but there are no proton channels in the outer one. ",
"(Note that aquaporins allow water to pass through but not H",
" , something that's rather remarkable)"
] | [
"The H+ ions are confined within the inner membrane which is where ATP synthesis occurs. It's the electrochemical proton gradient that forms between the inner membrane and the outer membrane that provides the required energy.",
"The function of the outer membrane is to mainly act as a barrier towards larger macro... | [
"Just to clarify, the protons pass from the Matrix to the Intermembrane space, and back again. They do not reside in either membrane for any significant length of time."
] |
[
"Does lying on your left side help digestion?"
] | [
false
] | [deleted] | [
"That is, in fact, a placebo. Given that your entire digestive tract is a series of muscles that involuntarily allow/block food from going anywhere, it is highly unlikely that any change in orientation would be good or bad for your digestion. Unless, of course, you have acid reflux like I do, in which case you don'... | [
"Digestion won't be effected, however, you could reduce the amount of acid reflux by being on your left side. Because the way your stomach is situated, if you are on your right side, the stomach contents will actually be sitting on the cardiac sphincter because the stomach is leaning on its side. This does not occu... | [
"Peristalsis, wooooh! Anybody ever seen intestines taken out of someone during an operation. The first time I saw that, the amount of movement from these systematic contractions really took me by surprise."
] |
[
"If both electrons and photons are pointlike particles, shouldn't the chance of a photon interacting with an electron be zero?"
] | [
false
] | null | [
"The fact that objects can be of zero-volume doesn't preclude the usual physical forces from making them interact, gravity, electromagnetism and the weak and strong nuclear forces are not contingent on particle size. ",
"As an aside, I am not sure I would state the photon to be a point like particle. In its basic... | [
"You have to be careful when thinking about subatomic particles and other fundamental physics'y things and what assumptions you make. I'm assuming that you're envisioning the electron and photon as both infinitely small points, and with that in mind, it seems reasonable that they shouldn't ever \"bump into\" each ... | [
"Electrons and photons cause fields which interact with other charged particles. A good example is an electron classically scattering off an electron. The incoming electron is scattered because of the others electron field. ",
"The particles that do not interact much are the neutral particles such as neutrons. Th... |
[
"What is e in regards to natural logarithms?"
] | [
false
] | I know that it is 2.71828, but what does it mean? Why is it important? | [
"Oh this is such a fun question!",
"The number's importance starts with one key observation. ",
"Let a>0 be a real number, we can define a function f(x)=a",
" ",
"What is the derivative of this function?",
"If we look at the limit definition of the derivative we get",
"f'(x) = lim h->0 ( a",
" - a",
... | [
"e appears in lots of places one might not expect, but one of the simpler appearances can be seen in terms of a financial application. ",
"Let's suppose you invest some money ($100) in an account earning 10% interest (wow!), but the bank only compounds the interest once a year. How much do you have after a year?"... | [
"The natural logarithm is the area under the curve y=1/x between 1 and some number. When that number is e, the value of the natural logarithm is 1. So the area under the curve y=1/x between 1 and e, is 1. Between 1 and e",
" it's 2. Between 1 and e",
" it's 3. So you can see that the natural logarithm gives... |
[
"Of what does one die when one is burnt to death?"
] | [
false
] | Hello, ! Reading about the Inquisition I came to wonder as to what the fatal part of immolation is. Is it the excrutiating pain and shock, extensive tissue damage or inhaling of the fumes? As macabre as this may sound, I cannot for the death of me come up with a satisfactory answer. Thank you! | [
"It depends on the circumstances. In large fires, the smoke inhalation usually kills the victim first, but in a smaller fire, death usually results from tissue damage, heatstroke, or blood loss.",
"Source"
] | [
"If they make it to treatment, cause of death is likely to be infection, or hypovolemic shock. ",
"ARDS",
" and ",
"DIC",
" are other complications they're likely to encounter or die of."
] | [
"I would imagine asphyxiation would become a problem, as well.",
"If you are inhaling flames you're likely to completely torch your lungs."
] |
[
"How do ISP's limit the speeds I get?"
] | [
false
] | null | [
"their equipment drops packets that cannot be sent within the limits of the contract for your connection.",
"network routing works by a store and forward principle. the packet is read into the memory of the router\nand then either discarded and overwritten or read from memory and sent along the cable.",
"the so... | [
"Yep. They can also delay them which also helped to throttle the connection. TCP is built on the premise that there network is unreliable and will drop packets if something goes wrong. If it a packet goes missing the sender doesn't get the acknowledgement that it is expecting, so it will retransmit the packet, but ... | [
"Yep. They can also delay them which also helped to throttle the connection. TCP is built on the premise that there network is unreliable and will drop packets if something goes wrong. If it a packet goes missing the sender doesn't get the acknowledgement that it is expecting, so it will retransmit the packet, but ... |
[
"How do astronomers know the trajectory of very far away objects?"
] | [
false
] | Blue/red shift should only give the component of the velocity that is towards/away from the observer But that still leaves two other axes So what methods are scientists using to determine the other two components of the velocity of very distant objects (i.e. distant galaxies)? edit: by "trajectory" I meant "velocity" | [
"I'm not sure what you're referring to. We can measure the radial velocities (those towards or away from us) of galaxies due to redshift, but tangential velocities (those tangential to our line of sight) we can't. At least not that I'm aware of (never discount an astronomer's ability to find some clever way to esti... | [
"So we don't know if Andromeda is moving side way and not have a collision with us at all?"
] | [
"I'm not an expert on this so please don't take this as gospel, but the fact that we're the largest thing around (besides Andromeda) means that any velocities these two galaxies have tangential to each other should be less than significant."
] |
[
"What happens when the ice cap melts and we have a ice-free summer in the arctic?"
] | [
false
] | null | [
"What you aren't considering is that ice is less dense than water, which is why some of it sits above the surface to begin with (but still has the same mass of the portion of liquid water that it froze from). Once it melts, it resumes the density of water which then takes the precise amount of space under the surfa... | [
"Sea levels do not rise when sea ice melts. The water from the melted ice occupies the same space as the previously submerged portion and the water level is unchanged."
] | [
"After some reading it seems that there is not enough ice on the north pole to make much of a difference in sea-level ...however if the south pole melted, the sea level would ",
"rise about 200 ft. (61m)"
] |
[
"If Humans breathed 100% oxygen from birth would we be bigger? Any other effects?"
] | [
false
] | [deleted] | [
"Why would an increased oxygen intake make us larger?",
"We'd be dead, in all honesty. Newborns suffer retinopathy (which for ease of explanation we'll just call blindness) in O2 environments about .6 for extended periods of time. Then of course, long time periods on 100% can lead to CNS disorders, oxygen is to... | [
"I believe that only works in insects, not all animals, and it's simply one of the postulated hypotheses for why it occured.",
"Slate has a helpful, albeit brief article."
] | [
"I had read somewhere that the reason animals were bigger in the dinosaur ages was because of a higher oxygen ratio in the air.",
"While pure oxygen would surely harm us, if not ignite and roast the earth, would a slight increase not allow us to be bigger? Much as the fauna was previously?"
] |
[
"Why do smartphones know the answer to (170!) but show as infinite the answer to (171!) ?"
] | [
false
] | null | [
"Wrong. Most general-use calculator software uses 64-bit IEEE floating-point representation internally; reasons for that include representation of very small fractional numbers with high precision (which you don't get with 1024-bit ",
") and of course the fact that it's available in pretty much every programming ... | [
"It's still the case that the cause of seeing an infinite result is due to overflow. "
] | [
"This is the most likely correct answer, yet impossible to tell unless OP specifies exactly which calculator app they're referring to.",
"PS. You got 171! incorrectly, it's ~1.24101 * 10"
] |
[
"Could I survive jumping out of an airplane over the sea, strapped to a massive, long, narrow iron spike"
] | [
false
] | EDIT: I was thinking the plane would be moving slow enough and be high enough that the spike and me would be falling directly downward at terminal velocity. The main question being can I some how survive this drop w/o a parachute, so any other add ons (fins, dif material, a quick release strap etc) are welcome. | [
"Theoretically, if you had the perfect entrance angle, and a properly shaped spike, you could safely decelerate after hitting the water.",
"This wouldn't be my first choice for an open-water free-fall safety device, though."
] | [
"I'm pretty sure surface tension is irrelevant to the rate of deceleration. Mythbusters did this, I can't find a more reputable source though."
] | [
"He is postulating that the forward velocity would kill you, not the downward."
] |
[
"How do you look at snowflakes under a microscope?"
] | [
false
] | null | [
"Use super glue\n(Directions from Popular Science)",
"Here's how you do it:\n1) Go outside with some glass microscope slides, cover slips, and superglue (not the gel kind; it should be thin and watery). Cover the slides and cover slips until they become as cold as the surrounding air. ",
"2) Let snow crystals... | [
"and singling the flake out? how much work does it take to do this effectively? What about condensation?"
] | [
"I don't know, I've never done that exact experiment but probably there are appropriate tweezers. I have tried freezing things while looking at them under a microscope, and to deal with condensation we blow some air between the lens and the glass. "
] |
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