title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"AskScience Cosmos Q&A thread. Episode 10: The Electric Boy"
] | [
false
] | Welcome to AskScience! If you are outside of the US or Canada, you may only now be seeing the ninth episode aired on television. If so, This week is the tenth episode, "The Electric Boy". The show is airing in the US and Canada on Fox at Sunday 9pm ET, and Monday at 10pm ET on National Geographic. Anyone can ask a qu... | [
"Why was the glass block so important in the polarization/electromagnetism experiment?"
] | [
"More cosmic rays hit near the Earth's magnetic poles than the rest of the planet (hence the auroras usually occurring near the poles). Fortunately the atmosphere stops most of the radiation from reaching the surface. However aircraft flying over the poles can receive significant amounts of radiation, and sometim... | [
"Since cosmic rays cause mutations in DNA, and they follow the earth's magnetic field toward the Van Allen Belt, is the spot where it comes down to the earth's surface a dangerous place to be? Can you get cancer if you stay in it too long? Is it a dead zone?"
] |
[
"Can anyone identify this?"
] | [
false
] | Approximately ten years ago, I found in a creek bed in Indiana. I've always thought it was a fossil of some kind, but maybe that is just wishful thinking. The cross-section shows structures that do not appear to simply be rock. Perhaps it is some type of worm? | [
"You can also try asking at ",
"/r/whatisthisthing",
" "
] | [
"Check out ",
"/r/fossilID",
"."
] | [
"My apologies AskScience, this didn't belong here. I reposted: ",
"http://www.reddit.com/r/fossilid/comments/118z9c/huge_worm/",
". Apparently, it's a Rugosa coral."
] |
[
"Is there a limit to the syntactical complexity of languages humans can learn?"
] | [
false
] | We're told that babies can learn any human language, but is there a limit to the syntactical complexity of a language? Could I come up with a language so complex that humans are unable to become fluent in it, and if so, does Science have any idea of what those limitations are like? | [
"http://en.wikipedia.org/wiki/Ithkuil",
"\n",
"http://www.ithkuil.net/",
"This may be of interest to you. It's a language with essentially no grammatical or syntactic ambiguity. This is achieved through very complex grammatical and syntactic structure. It does, however, apply these rules consistently, so I... | [
"What an interesting question. I have only some related commentary for you, not an exact answer.",
"Human languages are not arbitrary; the human brain appears to be born with built-in biases that certain syntaxes are okay and others are not. Part of this is called the ",
"language instinct",
". Thus there are... | [
"Personally, I don't think you'd be able to invent a language that no one can learn. language is, after all, simply a set of rules that need to be followed when communicating. Humans are great at learning and adapting to work within sets of rules (normal language, mathematics, etc). It might be extremely difficu... |
[
"Second attempt. I made an false color image of the moon and asked myself how accurate the data is. [image inside]"
] | [
false
] | [deleted] | [
"The precise colors you see depend on a lot of things: the atmosphere, the glasses that make up the lenses in your camera/telescope, the efficiency of the detector (and its spatial dependence), the filters, the processing that makes it into a color image, and finally the composition of what you're looking at. ",
... | [
"I know. Doesn't stay out if you're shooting with a refractor. The question is, does the aberration washes out all the data? "
] | [
"I know. Doesn't stay out if you're shooting with a refractor. The question is, does the aberration washes out all the data? "
] |
[
"2 x Tesla: 1) How feasible and safe are Tesla's ideas for wireless electricity? 2) How much truth is into that particle beam weapon?"
] | [
false
] | [deleted] | [
"Tesla, of course, wasn't concerned with such issues, as his plan was to give away electricity for free.",
"Also, regarding the ionosphere stuff, afaik he was merely using the ionosphere to effectively complete the circuit with the ground, not as some magical energy source."
] | [
"The example of wireless charging is already in use. Over very short distances for very small loads, it's a convenience. Anything farther than that and it becomes a power sucking parlor trick. (not a problem when you're Tesla and have your own generators.)",
"As for particle beams, it suffers from the same basic ... | [
"There is a whole Hell of a lot of hassle embedded in that \"simply\"."
] |
[
"Should we deposit radioactive waste into the ocean trenches instead of trying to bury it in mountains and caves?"
] | [
false
] | My understanding is that the continental drift zones have areas where new 'surface' (even if underwater) is created and old surface is destroyed (subduction). Would it make sense to deposit the radioactive materials into these subduction zones where they will be pulled into the circulating magma? It takes these magma f... | [
"While maybe that would help with the super-long term problem IF it survived long enough to be pulled under (maybe a geologist can tell us how long that would take), the problem with this that jumps out to me is corrosion. If you keep the waste underwater, you're risking corrosion over 10's to 1000's of years, whi... | [
"Problems include:"
] | [
"It is not about the radiation getting past the water.",
"It is about the radioactive materials themselves being carried by prevailing currents and entering the ecosystem."
] |
[
"Why did Eris, the dwarf planet that caused Pluto to get demoted, only get discovered in 2005?"
] | [
false
] | null | [
"Are these things just too dim?",
"Yes. Although Eris is the same size as Pluto, it's more than twice as far from the Sun. So not only does it have much less sunlight to reflect, it is much farther from Earth. That made it much dimmer and more difficult to find than Pluto.",
"instead of being able to look direc... | [
"I don't know for a fact but I'd guess it would be due to its ",
"highly eccentric orbit",
". Most of the time it's also further from the sun than any other planet in the solar system, and not on the same plane as the rest of the planets, so you just wouldn't know where to look. Anything smaller than a major pl... | [
"You might be interested to look at it in terms of angular diameter, which in this context you can think of as how wide a body appears to be in the sky; how much of the sky that body takes up.",
"The Sun is 31′31″ – 32′33″. There's 60 arc seconds (″) in an arc minute (′) and 60 of those in 1 degree, so the Sun ta... |
[
"I read in my astronomy textbook that our observable universe is 14 billion light years. Does that mean 14 billion light years in all directions?"
] | [
false
] | [deleted] | [
"1) The Big Bang happened here. It happened in Andromeda. It happened in the most distant galaxy we can see. It happened everywhere. It was not an explosion somewhere in space sending galaxies in all directions; it was, and still is, expansion of space itself between the galaxies. The universe is evenly filled with... | [
"Saying that there's nothing to see is different from saying that there's nothing there. There's certainly something there; we just can't see it, since light has not had time to get to us yet. "
] | [
"I read in my astronomy textbook that our observable universe is 14 billion light years.",
"About 14 billion ",
", yes. Not 14 billion light-years wide in radius.",
"Does that mean 14 billion light years in all directions?",
"The short answer is, no, it doesn't. Explaination coming.",
"1)Are we assuming... |
[
"Does the total surface area of two submerged air bubbles remain the same if they merge?"
] | [
false
] | null | [
"No. Volume scales with the third power of the radius, while surface area scales with the square of the radius. Merging two bubbles will create a bigger bubble, but the surface area will be less than the sum of the two original bubbles.",
"EDIT: there are some more complications I guess, like the tension in the b... | [
"Solve volume for radius:",
"Plug that into the equation for area:",
"Since we’re interested only in proportionality, a constant ",
" can be defined as 4π (3/(4π))",
" and then omitted:",
"Thus, if the volume is ",
", the surface area increases by 2",
" or ",
". In general, this proportionality is ... | [
"The shape and conclusion of this is entirely correct. But the volume of the sphere is 4π/3 r",
" , not 2π/3 r",
" . This correction disappears into the constant of proportionality (k) though, which is why the conclusion is still correct."
] |
[
"Why is the Fibonacci sequence so prevalent in nature and space?"
] | [
false
] | null | [
"The idea that the Golden Ratio and Fibonacci sequence occurs everywhere in nature and human esthetics is regarded by many as a pure myth: See e.g. ",
"this article",
" by mathematician Samuel Arbesman, and ",
"this one",
" by Prof Donald Simanek. ",
"Here's one",
" that debunks some of the claims in mu... | [
"The short answer is that nobody's entirely sure. A good guess is that organic growth tends to be governed by the simplest suitable recursive pattern, and simple recursive patterns tend to produce fibonnacci numbers. To give an idea why this is the case, consider ",
"this",
" pattern of algae growth."
] | [
"It isn't really, it's just that a lot of people attribute it to random things. See here: ",
"http://www.lhup.edu/~dsimanek/pseudo/fibonacc.htm"
] |
[
"What happens at the atomic level when we touch something?"
] | [
false
] | Somewhere I read that we actually can't touch, that it's all the repulsion between the negative charges of the atomic electron clouds. This is hard to accept from a macroscopic viewpoint, for example, every machine would be frictionless. I searched to see if this was asked before. It wasn't, but this is a in other site... | [
"Appropriate.",
"As to your question, wikipedia says that \"Friction is not a fundamental force but occurs because of the electromagnetic forces between charged particles which constitute the surfaces in contact. \" So, it's like passing one magnet over another--once they are close enough, it's pretty difficult t... | [
"electrons have negative charge, so they always repel, therefore it should be easier to be frictionless.",
"Layman -",
"You're thinking on a much too small scale. Surfaces aren't perfectly smooth, so you don't have a flat surface of negative charge coming into contact with another negative charge, you have a VE... | [
"The thing you have to understand is that surfaces (at least ones we tend to deal with) are not smooth down to the atomic level. They're bumpy at a much larger scale - if you put \"flat\" objects together, there isn't a plane you could cut through that would leave all of the first object on one side and all of the ... |
[
"Why is the tibia so close to the skin and not surrounded by muscle/fat like the other bones i.e femur, ulna, and radius?"
] | [
false
] | Why do we have no protection for bumping our shins?? Haha | [
"Bones usually have 2 main fascial compartments around them. A flexor and extensor, and some have a medial compartment too. There is no real need for a strong dorsiflexion action in the lower leg (bending your foot upwards), the muscles are used mainly for stabilization and so there are no large muscle groups there... | [
"It's also not a good candidate for fat deposits because it requires more energy to move mass at the end of your leg than your thighs or upper body. "
] | [
"Thank you, this seems to be the most widely accepted conclusion."
] |
[
"Why doesn't ice rotate in a glass of water when the glass is rotated?"
] | [
false
] | It seems intuitive that it would--is there some force working against the rotation or just a lack of a force where I am intuiting one? | [
"Let's say you put a piece of paper on top of a pool of water. You move the paper - do you expect the whole pool to move with it? Intuitively, you would expect only the water in the vicinity of the paper to move.",
"Likewise, when you twist a glass of water, the walls of the cup only exert force on the molecule... | [
"The ice essentially follows the motion of the water in your glass. When you rotate your glass, you're rotating just that: the glass. The water may begin to swirl as well because of frictional forces between the glass and the water, but these can be small."
] | [
"Thanks! Great examples--made it very easy to visualize my mistake."
] |
[
"Projecting an image on the moon's surface"
] | [
false
] | Could we build a projector capable of projecting an image onto the moon that is visible from Earth (weather permitting)? | [
"relevant ",
"what-if.xkcd.com #13",
" comes pretty close to answering your question.",
"basically, don't hold your breath."
] | [
"Expanding on OPs question, would it be possible to project an image from a satellite to the surface of the moon, viewable from earth? Bypassing weather systems and our atmosphere in the projection phase, the atmosphere would still be a variable in viewing the reflected light. I think it would be fair to assume a h... | [
"and we would need to find a material that would not vaporise or a way to dissipate all that filtered energy. Once we have that technology, we could aim the device at the earth and ask for a million dollar."
] |
[
"Vitamin D - When it is sunny, what's the minimum length of time (& skin exposed surface area) needed to get a good amount of it?"
] | [
false
] | [deleted] | [
"Even when the sky is overcast with clouds, sunlight still gets through, it's a misnomer that clouds completely block the sun. UVB rays are responsible for skin interactions that produce vitamin D. On a completely cloudy day, it is true that up to 90% of UVB can be blocked, but an interesting phenomenon in partial ... | [
"You can still get UVB from the sun in winter, whoever told you that you can't is wrong.",
"Hmm, according to ",
"https://www.ncbi.nlm.nih.gov/pubmed/2839537",
" no D3 was produced by people in Edmonton, CA (Which is about the same latitude as me in the UK) from October to March.",
"Edits - and when I ent... | [
"The conversion to recommended daily dose I've heard from reliable professor in my department is 15-20 minutes of exposure with uncovered face, arms, and neck with no cloud cover at a time of day and year when your shadow is shorter than you are tall. He went through a lot of math and there is some rounding and as... |
[
"How do we know dark matter is actually a thing and not a mistake in the gravitational equations?"
] | [
false
] | [deleted] | [
"There is a ",
"FAQ",
" on this topic."
] | [
"TLDR bullet cluster. The bullet cluster is formed by the collision of two large galaxy clusters, and in x-rays, you can see a tangled mess. However, you can directly infer the mass density using gravitational lensing (the bending of light behind the cluster) and doing this you find that the majority of the mass o... | [
"You're thinking of dark energy. Dark matter shows in situations like the orbits of stars in galaxies where the speeds at which they orbit indicate much larger masses than what we can observe as regular matter."
] |
[
"In babies and small kids what is the reason of timing vaccines with age? Why can't all vaccines be given at the same age?"
] | [
false
] | null | [
"Babies survive initially on their mother's natural antibodies (shared through the placenta and then through breastmilk) until the baby itself has developed an immune system capable of protecting itself. The thymus in particular is an organ that needs to develop for a while before it can handle any vaccines. Otherw... | [
"[For context I am a PhD candidate studying newborn immunity]",
"The common and accepted answer is that the newborn immune system is just immature, because it is easy to understand and makes intuitive sense. However, many who specifically study the neonatal immune system (myself included) are trying really hard t... | [
"Is the immune system simply too complex or energy intensive to exist in babies from birth, or is it advantageous to not have immune response as an infant?"
] |
[
"What is going on with our eyes and brain when we are looking at a TV and see a picture with depth on a 2D surface?"
] | [
false
] | [deleted] | [
"The main depth cues your brain uses to reconstruct a scene are 2D. Things like the angle a line makes on your retina as it recedes are far more important than binocular depth perception. You can demonstrate this yourself: when you cover one eye, the world doesn't suddenly look flat. ",
"For one eye, it doesn't ... | [
"Interesting, thanks!"
] | [
"You can demonstrate this yourself: when you cover one eye, the world doesn't suddenly look flat.",
"This is true, but you should try (if you haven't) covering one eye for many hours. It happens slowly, but the world does seem less and less depthful, and after ~8hrs, everything seems weirdly flattened. It's a str... |
[
"Could Venus have supported life in its past?"
] | [
false
] | Do we have evidence that Venus has always been the hellscape it is now or could it have had a milder climate in the past? | [
"Whereas we have solid mechanism for how planets loose atmosphere, (",
"https://en.wikipedia.org/wiki/Atmospheric_escape",
"), there are no plausible mechanisms by which a planet could capture the huge amount of gas that the find in venus. Volcanic outgassing and cometary strikes are possible, but venus atmosph... | [
"Wouldn't it have been possible for the atmosphere to change composition in the past?",
"It's happened on Earth before. Although at 96.5% CO2 the atmosphere on Venus probably always had a pretty high concentration of CO2 and must have been pretty hot."
] | [
"But but but aren't you guys all assuming that when OP says \"support life\" he's saying \"support Earth-like life\"? I mean, as far as I understand, we don't really know if there are other types of non-Earth-like-life that could exist in Venus' current/past atmosphere...",
"So shouldn't the real answer be in the... |
[
"If matter can't be created or destroyed, how do pairs of quarks just \"pop\" into existence?"
] | [
false
] | I was watching a video on subatomic particles and the narrator mentioned if two quarks get too far apart from one another, an entirely new quark will appear to form two pairs. How is that? | [
"matter can be created and destroyed. This is exactly what every nuclear reaction is.",
"In order to separate a par of quarks, you have to put a sufficient amount of energy into them to produce two new quarks.",
"The simplest way is by accelerating things real fast and smashing them into each other. This is e... | [
"There is energy in the field between the two quarks. As you pull the quarks apart, you are doing work on the system, and so increasing its energy. Eventually that energy is large enough to create a quark-antiquark pair."
] | [
"False. Antimatter does not have negative mass, but opposite charge. Annihilation of matter and antimatter yield energy equal to that of the combined masses. "
] |
[
"How do fields exert force over distance?"
] | [
false
] | [deleted] | [
"The charge interacts with the field where it is. The field at that point interacts with the field at a slightly displaced position. And so on and so on until it reaches the other charge.",
"One says that all interactions are local, happening either at the same point or at very close points (mathematically one sp... | [
"There is no medium, there is an intermediary which is the field. The field is like an infinite collection of degrees of freedom at each point in space. Just to be clear: it is not a mathematical trick, it is a real thing. These degrees of freedom can be excited and they can pass on energy to nearby degrees of free... | [
"You've got it backwards: fields are responsible for particles. Each and every fundamental particle (electron, gluons, quarks, etc) has an associated field. These fields permeate ",
", and since they have fluctuating energy the \"empty space\" between planets isn't truly empty at all. In fact, the vacuum is fille... |
[
"If blood is taken from a human corpse several hours after death, can lab tests detect that the blood sample was taken from a dead person?"
] | [
false
] | I'm aware that blood coagulates several hours after death. So does a blood sample taken from a person who has been dead for several hours contain markers that distinguish it from blood taken from a live person (or very recently dead person), and can these markers be detected through forensic testing? | [
"Yes there are several markers available. Blood cell morphology is widely used for example. I am no expert on this field - but this paper should answer your questions: ",
"Estimation of post-mortem interval using biochemical markers",
"I uploaded the pdf ",
"here",
". ",
"Some excerpts:",
"Edit: Similar... | [
"Not a stupid question at all. I do not have very detailed insights in the blood physiology ... but: Everything in our body is tightly connected. Just look at the ",
"components",
" in our blood. All these components are regulated by enzymes and or channels in the surface of the blood vessels and each of these ... | [
"I always think of brain death. The brain has only a few minutes of run time once the blood stops flowing or you stop breathing. If you quickly tested oxyhemoglobin of a person's blood sample, you would see it depleted to a point you would know the sample was from a dead person. ",
"I even read excerpts from a 19... |
[
"do electrical circuits overheat in vacuum?"
] | [
false
] | null | [
"Yes. Power in a circut is I",
" * R (current squared multiplied by resistance). Unless you're running a DC superconductor, you have some finite resistance, which will produce heat in the circuit.",
"In fact, a circuit is much more likely to overheat in a vacuum than it is in air. This is because vacuums ins... | [
"They're more likely to overheat, yes. Two of the three ways (convection, conduction, and radiation) that heat is dissipated aren't available in a vacuum, leaving only radiation. ",
"It's one of the things the ISS has to deal with-- in ",
"this picture",
", for example, you can see solar panels, and a bunch... | [
"Radiators don't require a medium to transmit heat into. The devices commonly called radiators (in cars, houses) primarily transfer heat by conduction and convection. Radiation is the emission of energy from a material. Energy = heat effectively.",
"A sheet of metal in space, but out of direct sunlight, quite qui... |
[
"What exactly are VPN’s and how do they work?"
] | [
false
] | null | [
"Imagine you have to do everything by mail, and you don't feel safe sending postcards due to your post office being staffed by your overprotective mother. A VPN is like putting the postcard in an envelope to your buddy who is away at college. Your buddy opens the envelope and resends the postcard. He gets a respons... | [
"All of your traffic that goes to the VPN adapter is addressed to the same destination (the VPN gateway). Inside those packets (encrypted) is another packet with the real destination and contents that you want. ",
"The VPN gateway unencrypts the packet and sends it on its way with a source address that’s part of ... | [
"It's not necessarily that Netflix cares. Region locks are mostly due to distributor restrictions/requirements only allowing certain content to be shown in certain areas, which can be done for a variety of reasons."
] |
[
"Is it possible for a moon's orbital period to coincide with its planet's revolution in a way that causes a \"new moon\" that could last for years?"
] | [
false
] | null | [
"In order to remain in a new moon phase the moon would have to be positioned near the Earth-Sun L2 ",
"Lagrange point",
". The Lagrange points are 5 points where a small body can will appear stationary (in a rotating reference frame) with respect to two larger bodies that are orbiting a common center.",
"If t... | [
"Doesn't the instability also mean that a moon would never form at L2 in the first place?"
] | [
"That would make sense, however the Moon is also slowly moving further away from the Earth. Perhaps given enough time (and nothing else interfering, which I'm sure is highly unrealistic) it could drift into an L2 orbit?"
] |
[
"Is it possible to change polarity of a film of some sort using voltage or current?"
] | [
false
] | Im thinking something like when youre holding up two 3d glasses and when you tilt one 90degrees and it turns dark, achieving the same tilt but using current or something like that. This feels like material science, which is why I ask here :) | [
"What you are describing is exactly how a ",
"LCD display",
" works. \nIn this video someone creates his own LCD display and goes in depth about the process to make it work.\n",
"https://www.youtube.com/watch?v=d4QFNWBSZYg",
"In short, a LCD display consists of two polarizers, and a liquid in between that ... | [
"This. Same goes for self-dimming mirrors in cars (which are basically one giant pixel over the whole mirror) and the clever window blinds on the Boeing 787."
] | [
"Would you care to elaborate on the blinds used in the 787? Is it also 'one giant pixel'?"
] |
[
"A facebook \"friend\" is trying to sell these things but I've told him there's no way they can possibly work: USB to 110V AC converters."
] | [
false
] | null | [
"Your suspicions are correct, there's no way to boost 5v DC @ ~1A to 110-120v AC with anything approaching useable current. You could cheat for a very short time with a gargantuan capacitor bank but that's clearly not the case here.",
"e: Don't hair dryers draw >1kW? 10-15A on AC sounds about right. And max US... | [
"The DC to AC part is not the unbelievable part.",
"When a USB port supplies 10 Watt of power it is considered a lot (e.g. iPad charging)",
"Even if you could manage a lossless conversion from 5V DC to 110V AC (which you can't) you would be worlds away from powering a hair dryer."
] | [
"So report him. Facebook has pretty clear rules about scams and spam."
] |
[
"Do all photons in sunlight have the same energy?"
] | [
false
] | null | [
"No, sunlight is black body radiation. It emits photons with a huge range of energies, some more common than others. IIRC it emits more green photons than any other. The atmosphere blocks most of the range, but what gets through are mostly the photons with energies that our eyes are able to detect. Red photons have... | [
"It is very rare that I find someone admit the sun is white, not yellow. Thank you!"
] | [
"Hm, all you need is to show them a picture of the sun from the space station!\n",
"http://www.nasa.gov/mission_pages/station/multimedia/gallery/iss036e002224.html#.VEl8o_ldWy8",
"Although the sun is even pretty white when it's high in the sky from earth."
] |
[
"How did HIV/AIDS pass onto humans?"
] | [
false
] | [deleted] | [
"Current understanding is that it transferred from monkeys (in the form of SIV) to humans (as HIV) when humans ate infected monkeys. SIV and HIV are close. There has been a bunch of research into their relationship: ",
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2739573/"
] | [
"Not ate but hunted. Ingesting HIV is a very minimal chance of transmission; ingesting SIV through cooked bush meat would pose a negligible risk of zoonosis."
] | [
"Specifically, the point at which the highest chance of infection would have occurred was during butchering when the human would have been exposed to a large amount of internal fluids (blood and otherwise) from the monkey but none of it would have been cooked yet."
] |
[
"Is it possible to be motionless in space? That is, not hurtling around a sun or through a galaxy or any sort of velocity."
] | [
false
] | Since motion is really just relative, I imagine there would be no way of knowing if you're motionless or not? Assuming it is possible though, I think it would be interesting to sit motionless and watch giant systems fly around at astronomical speeds. | [
"It's a matter of definition. What does it mean to be motionless? It means two independent things. First, it means that you're not experiencing any acceleration. Acceleration is a real thing, and it can be measured with a purely local experiment, so that's easy to rule out. The second part is that it means to have ... | [
"Thank you for the reply, btw it was your comment about faster than light travel that spurred me to think about this and want to ask questions. I appreciate that you take time out of your day to entertain questions from the internet :)"
] | [
"In the whole scheme of the universe no. Relative to an object, yes. Check out this thread:",
"http://www.reddit.com/r/askscience/comments/el5e0/can_you_make_yourself_completely_motionless_in/"
] |
[
"What is a classical analog in science?"
] | [
false
] | null | [
"Can you give the context for where you saw this?"
] | [
"In the article titled \"A water wave analog of the Casimir effect\"."
] | [
"Then the article is probably talking about quantum effects. A “classical analog” to a quantum effect is a similar example to the quantum effect which happens in classical mechanics."
] |
[
"Is there a spot in the universe where The Big Bang happened? And if so, where is it now?"
] | [
false
] | null | [
"Is there a spot in the universe where The Big Bang happened?",
"Yes.",
"And if so, where is it now?",
"It's everywhere in the universe now. The \"spot\" where it happened covers the whole universe."
] | [
"You're thinking of the universe as a sphere that has expanded from a central point of origin; it's not. The ",
" universe looks like a sphere because we can only see a finite distance in any given direction. But there is exactly zero reason to think that the universe stops there -- in fact, the CMBR (being more ... | [
"You're thinking of the universe as a sphere that has expanded from a central point of origin; it's not. The observable universe looks like a sphere because we can only see a finite distance in any given direction.",
"I don't see what the observable universe has to do with anything. In the expanding sphere model,... |
[
"Is there such a thing as \"economic momentum\" and if so can it be measured, or can it be used to predict economic behavior?"
] | [
false
] | I'm wondering if the natural laws of physics apply to man-made systems, in this case, whether Newton's First Law of Motion (paraphrased), where a body will remain in a given state until acted upon by an external force, can be applied in some fashion to economic systems. To give an example, say applicable forces are con... | [
"Economics and Newtonian physics can share only the most shallow analogy. Using one to make conclusions and predictions about the other (and attempts to control) is more or less pointless.",
"You ",
" make strong analogies between economics, turbulence, weather patterns, and certain types of noise in electroni... | [
"The phenomena of social and industrial inertia could be seen to combine as economic inertia, or momentum as you say, but such an analogy to the laws of physics is only effective to a point, as you cannot draw conclusions beyond your understanding of economics based on a relatively more expansive knowledge of physi... | [
"As you mentioned before with your example of Newton's first law of motion; trade and foreign investment could be seen as an \"outside\" force that causes motion in stagnate economic factors such as GDP growth (though foreign investment isn't usually factored into GDP for the client country) or unemployment. But t... |
[
"Can butterflies remember being caterpillars?"
] | [
false
] | During the metamorphosis of insects it seems their cellular structure is completely reorganised. How much of the memory of the individual survives this? For example, if you "trained" a caterpillar or conditioned it to respond in a certain way would the resulting imago remember this conditioning? | [
"Yes, and it's actually quite amazing that it happens at all. The caterpillar's body breaks down to reorganize into it's adult form yet does retain memories. This was discovered using your example, conditioning. Caterpillars were conditioned to avoid a scent and remembered it as adults. However, it seems events are... | [
"Thanks for this. It makes one wonder how the memory is stored and retained under these circumstances."
] | [
"Not all of the caterpillar's tissue is reorganized. Some structures, including the gut and respiratory system, are conserved during metamorphosis. The brain may also be conserved, which would explain why butterflies can remember some things they learned as caterpillars. Here's the article with MRI scans showing ho... |
[
"How do scientists give mice cancer for study purposes?"
] | [
false
] | null | [
"You introduce genes that lead to guaranteed tumour development into the germ line of a mouse species, then continue to breed that line. The initial process can be tricky and expensive, though this may have changed in the past five years or so since I've done it."
] | [
"They breed mice with a predisposition to cancer.",
"http://www.vetmed.ucdavis.edu/Animal_alternatives/cancer.htm"
] | [
"Certain scientists use mice which have been specifically engineered to be immunodeficient, such as mice which do not have a thymus, due to a mutation in the FOXN1 gene. (",
"Nude Mice",
"), or mice which have severe combined immunodeficiency (SCID), where the entire immune system is non-functional, due to the ... |
[
"Why did the sea faring dinosaurs go extinct?"
] | [
false
] | I was hiking with my 9 year old son along the York River and we came to a place called Fossil Beach. This led to a discussion about how the ocean used to cover much of the land we live on and one question led to another as they often do with 9 year olds. Then he asked me "why did the dinosaurs in the ocean die?" He und... | [
"Not a direct reply to your question, but if you want all the smarty sounding bits for your son, there were no seafaring or flying dinosaurs (excepting birds). Rather those which we typically think of as such were reptiles.",
"To your direct question, it is theorized the extinction event massively depleted plankt... | [
"Plankton forms the basis if the food web in the ocean. They are green plants that photosynthesis sunlight for energy and are in turn eaten by larger animals, which are in turn eaten by carnivorous animals. When the comet hit that \"killed\" the dinosaurs it didn't directly kill them all. What it did do was inject ... | [
"And we know that the mammals were best prepared to survive the change on land.",
"Is there evidence of a giant die-off in the ocean at this time? Is it even possible to even have records like this in the ocean? ",
"It seems a failure of plankton would be catastrophic to all sea life. If we take today's seali... |
[
"Why is it that different substances burn different colours?"
] | [
false
] | I have an extremely basic knowledge of chemistry but just enough to know that sodium salt burns yellow and potassium salt burns purple, and I was wondering why this is the case and also why they don't all just burn the same colour. | [
"Fun little fact this process is responsible for the colour in fireworks typically elements such as sodium magnesium potassium added to the firework to give distinct colours"
] | [
"When a substance burns, it is clearly at a very high temperature. These high temperatures excite the electrons in that substance from the 'normal state' (called the ground state) to an excited state. ",
"Electrons prefer to be in the state of lowest energy, so shortly after the heat excites them from the ground ... | [
"Thanks for the answer, this is exactly what I wanted to know thanks."
] |
[
"What is the margin of error when launching a satellite into orbit? If too high it drifts off to space and too low it crashes to earth. How much difference are we talking about?"
] | [
false
] | Also, how is the Lagrange's points found? | [
"The other comment is correct, but I'd like to add: speed is even more important than distance.",
"The margin of error is not much. A satellite in a typical orbit at 400 km must move at 7.67 km/s. If my math is correct just 0.1 km/s less than that would cause it to reeenter the atmosphere and burn up. On the othe... | [
"Thanks so much!"
] | [
"If too high it drifts off to space",
"This height is ",
" high, as in about 1,000,000km. All satellites are within the orbit of the Moon as far as I'm aware, and in that region of space those satellites will stay there for up to millions of years.",
"Too low is typically about 300km. For example, the ISS is ... |
[
"Is there a direct link between the growth of facial hair and baldness in men?"
] | [
false
] | I was reading up on why my beard looks so awful and it seems that facial and body hair is stimulated by the conversion of testosterone into DHT. As far as I know, the effect of DHT on hair follicles is the primary cause of male pattern baldness. Is there any basis for assuming that men with better beards are more likel... | [
"In my case the hairs on my head realize they have turned gray, and commit suicide by jumping..."
] | [
"I have a personal theory, that each hair is an individual and intelligent entity. The hair on top of the head does not stop growing and fall out, it just migrates downwards due to milder climates and a more interesting view.",
"There is no scientific content in my theory. "
] | [
"I'm glad to hear someone else thinks the same way as me :)"
] |
[
"If a human were to be cloned, would the clone have identical fingerprints?"
] | [
false
] | null | [
"https://medlineplus.gov/genetics/understanding/traits/fingerprints/",
" ",
"Fingerprints are only partially genetic. They are also influenced various epigenetic factors in the womb.",
"",
"The basic size, shape, and spacing of dermatoglyphs appear to be",
"\ninfluenced by genetic factors. Studies sugge... | [
"Worked in a data center with biometric access (fingerprint and retina scanner), over the course of a couple of weeks where I put in a whole lot of new Ethernet cable, the ludicrous amounts of velcro I used for cable management wore my fingerprints off to a degree where the biometrics didn't recognize my fingerprin... | [
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338710/",
"This study shows that identical twin fingerprints differ, but not as much as they differ from the fingerprints of a non-twin. ",
"Since identical twins possess the same genetics, it is reasonable to assume that other forms of cloned genetics would lead t... |
[
"Is it possible to transform matter into anti-matter?"
] | [
false
] | If so what does it take? I'd assume lots of energy input? If not, why not? Thank you. | [
"To be pedantic, those conservation laws are actually ",
"violated by non-perturbative processes",
". In the standard model, these processes convert three baryons into three anti-leptons (so I guess this helps answer OP's question). The rate of these processes are totally negligible at current energies/temperat... | [
"It is possible to use matter to create anti-matter and vice versa through high energy interactions such as at accelerators, and nuclear decays.",
"An example of nuclear decay producing anti-matter is positron emission from beta decay.",
"Accelerators also produce anti mater by colliding matter particles at hig... | [
"You can create matter-antimatter pairs from a collision between two particles, but if we define baryon (lepton) number to be the number of baryons (leptons) minus the number of antibaryons (antileptons), these quantities will always be conserved. So if we have a proton and an proton collide, then initial baryon n... |
[
"Are all the stars in the sky within the milkyway?"
] | [
false
] | Someone once told me or i heard it somewhere, that all the nstars visible with the naked eye at night are all contained in the milkyway. Is this true? I don't know how to verify this. | [
"Yes and no. All the individual stars you can see are within the Milky Way Galaxy. Most of them are fairly close, within 10,000 light years, in a Galaxy 100,000 light years across. But even most of our own galaxy appears as a single cloud in the night sky; no discreet, individual stars are visible. Likewise, you ca... | [
"Yes, you can see other galaxies sometimes with a good telescope, but you can't see the stars in them."
] | [
"All of the answers here are correct, but I'd like to point out another thing:",
"The galaxy is filled with dust and gas which blocks out the light of many stars on the other side of the galaxy! So, the stars that you do see are mostly localized to our general part of the galaxy!"
] |
[
"Are there observable relativistic effects due to the speed of the solar system orbiting the galaxy?"
] | [
false
] | I saw in the New Scientist (25th June) that the solar system travels at 200,000km/s relative to the galaxy centre. This seems surprising close to the speed of light. Do we see relativistic effects as a result? For instance, do we see stars near the centre age more rapidly than models predict, or planets orbit stars ... | [
"I saw in the New Scientist (25th June) that the solar system travels at 200,000km/s relative to the galaxy centre",
"Whoa that's too big. That's like 2/3 ",
". You might have the units wrong, it's closer to 225-250 km/s (about 500,000 mph). While these may seem like hilariously high speeds, they're still paltr... | [
"Sure.",
"For example, ",
"this jet",
" from galaxy M87 is about 5000 light years long, and is relativistic.",
"We also observe cosmic rays and neutrinos (albeit in fancy expensive detectors) every day which are moving close to the speed of light. ",
"Of most interest to you is probably hypervelocity ejec... | [
"If the acceleration is mainly by gravity and reasonably uniform - yes. It is spatially non-uniform acceleration that rips things apart. "
] |
[
"Since time is not absolute, does it make sense to describe the age of far away galaxies in years?"
] | [
false
] | null | [
"It turns out the effect isn't that big in most real-life situations, but there is a convention we can use if we really want to be more careful when we talk about time.",
"Time runs at different rates depending on the relative velocities of objects, and also based on the strength of gravity fields. However, you h... | [
"That's the age as seen by an observer far away."
] | [
"Something else worth mentioning is that scientifically, the \"age\" of a galaxy is somewhat important in understanding it's properties, and in studying the way galaxies form and evolve over time. ",
"However, the time units used are practically irrelevant. You could make up some new unit of time if you want, and... |
[
"Is it possible to change our brain chemistry at will?"
] | [
false
] | [deleted] | [
"Directly? Absolutely not. You can't say to yourself: \"I'm going to reduce the level of cortisol being secreted by the hypothalamic-pituitary axis and thereby lessen my stress response.\"",
"Indirectly? Certainly. Deep-breathing techniques are a wonderful tool often used in Cognitive-behavioral therapy to teach ... | [
"Directly? Absolutely not. You can't say to yourself: \"I'm going to reduce the level of cortisol being secreted by the hypothalamic-pituitary axis and thereby lessen my stress response.\"",
"Indirectly? Certainly. Deep-breathing techniques are a wonderful tool often used in Cognitive-behavioral therapy to teach ... | [
"See, LSD. Or any kind of drug for that matter. "
] |
[
"In neuron depolarization, why does the cell use two types of ions (Na+ and K+) if they are both positive? Why not just use one type?"
] | [
false
] | Is it because one type is faster than the other at crossing the membrane? Or is it just because there is more sodium available in our diet? | [
"Na is being pumped out of the cell and K is being pumped in. There is a high concentration of Na outside the cell and a high concentration of K inside the cell. However for every 3Na coming out of the cell 2K are coming in. So more positive charge leaving the cell than entering. This difference of charges generate... | [
"This generally applies to all membrane potentials, not just to neuron depolarization. Basically, what it comes down to is that using multiple ions (Cl is also involved, as is Ca in some cases) gives the cells better control over the membrane potential; with multiple ions, you can have multiple signaling pathways t... | [
"As for the \"why\" part, it is very difficult for a cell to have such complex properties of action potential by controlling only one ion. Getting more ions involved allows it to control the process in a more automatic fashion. You can eat with only one hand, but using both hands makes it much easier.",
"First, p... |
[
"Has the growing % of the population avoiding meat consumption had any impact on meat production?"
] | [
false
] | null | [
"This site",
" has the answer.",
"It's just throwing numbers at you, so I just glanced at it, but meat consumption seems to be growing everywhere. World meat consumption is increasing like crazy, European meat consumption a little less, but still growing.",
"Is anyone from ",
"/r/dataisbeautiful",
" aroun... | [
"No.",
"For every member of the first world who decides to eschew meat, there is a population increase of much more than that.",
"Even discounting the population growth's effect on meat production, per capita the figure increases to grow. Worldwide, per capita meat consumption increased from 41.3 kilograms in ... | [
"It is worth mentioning that the rise in vegetarianism is mostly happening in Western countries which, collectively, are a small portion of the world population. Meanwhile, meat consumption is growing in developing countries - so all that is really happening to meat production is that they are selling to different ... |
[
"Why do you need to take malaria pills BEFORE you travel?"
] | [
false
] | null | [
"General rule of pharmacokinetics, start with high dose, probably double what the goal is. This gets the drug passed \"first pass\" which is removal by liver and kidney, but leaves \"target\" dose in the blood stream. Then keep dose steady, which takes a little while to reach equilibrium since the bodies natural re... | [
"Health care professional here. The reason for taking it before you leave is to build blood levels to the point of being effective before you enter the malaria risk zone. It also helps to assess for serious side effects, particularly with mefloquine, although it's obvious to me that you're taking Malarone. "
] | [
"Questions like this need to be directed at your doctor. We can't offer any advice about medication on ",
"/r/AskScience",
"."
] |
[
"Why is there a launch window for a geosynchronous orbit."
] | [
false
] | I just watched the SpaceX launch attempt, they had some issues, and the next launch window is in three days. If the satellite was being launched in a geosynchronous orbit, why does it matter when they launch it? (please excuse my KSP based understanding of orbital mechanics) | [
"That only means that the Falcoln 9 will only get the satellite to GTO, and the satellite will do a final burn at apoapsis to get into geosynchronous orbit."
] | [
"Possibly, I don't know the details of the mission plan. It might be longer because of terrestrial constraints like resetting the rocket and launch pad."
] | [
"the thing that doesn't make sense to me: if it's a geosynchronous orbit, wouldn't launching the satellite at any hour of the day put it in the same place?",
": satellite, not salivate, damn spellcheck :)"
] |
[
"What is the evolutionary reason for Australia's many poisonous critters?"
] | [
false
] | What is the evolutionary reason why Australia has so many poisonous snakes, spiders, jellyfish etc.? | [
"Evolutionary biologist and herpetologist here! I can answer the reason for the venomous snakes. ",
"The reason for the amount of venomous snakes has to do with evolutionary history. Essentially, Australia was first colonized by sea snakes (family Elapidae -- a family of venomous snakes -- the same family as cobr... | [
"Chris Lavers covers this question in ",
" which is a very readable book about how animals use energy and how basic physics and maths alter animal forms. ",
"A paraphrased, vaguely remembered summary of that chapter is: Australia is geographically old (all the rocks near the surface have been near the surface f... | [
"Not complete conflict. First of all, my answer only applies to snakes. SMTrodent and ymersvennson's answers explains why venom has persisted over time and why it would be advantageous for venom to evolve in the first place. Indeed, his answer is a good explanation for why venom may have evolved independently in Au... |
[
"Why do the veins of the arms pop out as they grow more muscular?"
] | [
false
] | I do realise that this may have an obvious answer, but can anyone with the knowledge behind it chime in? Also, isn't it a disadvantage from an evolutionary point of view for this to happen? Aren't they more likely to be damaged or avulsed as this happens? | [
"It has more to do with body fat percentage than muscularity. As body fat decreases, the space between skin and muscle decreases and vascularity become completely visible. "
] | [
"Do larger and more fit muscles have a higher demand for blood (i.e. than their wimpy counterparts), and would the body compensate by increasing the size of the blood-vessels that supply them?"
] | [
"Good question, some body builders look like they have abnormaly huge vains"
] |
[
"What is the lowest possible atmospheric pressure a human could survive in?"
] | [
false
] | [deleted] | [
"Humans begin so suffocate at around .16 pO2...at lower pressures, pulmonary gas exchange no long occurs at a sufficient rate to support respiration.",
"So, if you are in a 1/6th atmosphere environment of pure oxygen, your the alveoli in your lungs could still function. I suppose with acclimation you could lower... | [
"I found ",
"this",
" and ",
"this.",
" I think it has some answers."
] | [
"Perhaps the partial pressure of Oxygen on the top of Mt Everest would be a start."
] |
[
"What limits observation outside the \"observable universe\"?"
] | [
false
] | [deleted] | [
"The speed of light.",
"The observable universe is defined as a sphere, centered on the observer, with a radius equal to the speed of light times the age of the universe, in comoving coordinates. (That last bit is to deal with the metric expansion of the universe.)",
"People who say \"universe\" when they mean ... | [
"As the universe expands and more and more space between galaxies is created, will there come a time where our galaxy will be isolated to the point where no observation outside of our galaxy is possible? If humans had evolved 5 billion years later on Earth with all other factors being equal, how would our \"image\"... | [
"The fact we haven't been able to find traversable worm holes."
] |
[
"How do you calculate the total % chance of 2 things happening?"
] | [
false
] | null | [
"The product (0.05)*(0.15)."
] | [
"wow thats super simple, lol thank you\n so the chance of breaking through both walls would be .75%?"
] | [
"Yes."
] |
[
"What happens to the body when you fast?"
] | [
false
] | Specifically fasting for daylight hours (like in Ramadan). How does the body change and adapt. How long after the fasting stops does the body take to adapt back? One process I've heard that takes place is that due to glycogen leaving the liver and muscles that insulin tolerance resistance drops. How long does this last... | [
"With daylight fasting the changes aren't actually that dramatic. We have enough glycogen stores to tide us over for about 20-24 hours, so upon fasting, we just begin to catabolise glycogen. This provides the glucose which then fuels the rest of us.",
"The more dramatic metabolic change happens with longer period... | [
"The brain, however, can only metabolise glucose",
"Actually, the brain is capable of metabolising ketone bodies as well, and these are the key to long term starvation survival in (most?) mammals. I think there's also some evidence that the brain might be able to use lactic acid, but I don't have sources on hand.... | [
"Although this is a totally unhelpful answer - it depends how fat you are!"
] |
[
"What would a very powerful electromagnet do to the human body?"
] | [
false
] | null | [
"This is a very interesting question that I have discussed with colleagues but I don't know if anyone has really tested since the ethics are a bit... unsettling. ",
"From what I understand, as long as you have no ferromagnetic objects in your body, even very powerful DC magnetic fields won't really affect you. ... | [
"Strong static magnetic fields usually aren't an issue for living tissue. Magnets have very little effect on people since we are mostly water. 7 Teslas or below is considered pretty safe for MRI machines. Like others have mentioned, the main issue I've heard of is from the dB/dt, or change in magnetic field w.r.... | [
"If we have crazy futuristic superconductors, we could get 100-1000 Tesla magnets.",
"Superconductors have a limiting field strength, normal conductors have not. The strongest fields we can produce are from normal conductors (~100 T short-term without destroying the equipment, and ~50 T long-term)."
] |
[
"Which constellations would differ if viewed from Mars or is the difference in viewing angle too slight to detect any difference at all?"
] | [
false
] | null | [
"Considering Earth all by itself pretty much answers this question. ",
"In January and in July the Earth goes one-half of its orbit around the sun, making it 298,000,000 kilometers from its starting point more or less (and not counting the sun's movement as it traverses around the Milky Way galaxy). We don't see ... | [
"You have to go way further than Mars to see any difference in constellations. Even going to the next nearest star, Alpha Centauri, will only alter the night sky slightly. There are some computer programs which have the nearby stars in 3d, rather than a 2d skymap, and let you travel around the galaxy so you can see... | [
"There would be no perceptible difference. Most of the stars we see in constellations are dozens or hundreds of light years away, so a change in distance of order 1 AU would be far too small for us to notice. It would be a bit like looking at a mountain tens of kilometers away and moving your head an inch or two to... |
[
"How can any animal withstand 497 atmospheres?"
] | [
false
] | Specifically, the deep-ocean who lives comfortably 16,400 feet down where (I calculate) the pressure is about 7,200 psi. Even though he's only 7 inches long, still, normal only has a compression strength of 6,000 psi. How can this even be possible? | [
"The pressure on the inside and outside of the fish is equalized. If you take a pressure vessel full of air and submerge it to the bottom of the ocean, the vessel must resist the entire pressure difference. If you open the vessel and let water inside, the pressure on the inside and outside is now the same, and the ... | [
"Because the interior of the fish's body is also pressurized to that same level.",
"We do the same thing with air. Your body is currently subjected to the equivalent of about 20 tonnes of pressure from the Earth's atmosphere, but you don't feel it because your body is pressurized to that same level. The fish just... | [
"Thank you, and that seems pretty obvious now.",
"Still -- it seems miraculous..... And I wonder, do you think that the extreme pressure at ocean depths would mimic the effects of gravity? Would these fish \"weigh\" more.... would their time move slower? I wonder if anyone has ever tested that notion"
] |
[
"How did the first single celled organism come into existence?"
] | [
false
] | Had this question thrown at me today in a Religious Studies class (essentially philosophy and ethics) and I couldn't answer it. But I know there has to be someone out there with a good idea of the current theories surrounding this issue. Thanks! | [
"Well it doesn't just happen. ",
"First the universe must create enough carbon, and organic molecules to make their dispersal around the universe high enough for conditions where more complex organic compounds can form. This happens through fusion, fission, and the processes of element creation in the cosmos. "... | [
"This lecture",
" is fantastic. It is much more detailed than the other video linked here.",
"I would highly suggest watching the whole series. If you're not planning to work in the life sciences then this course will give you everything you need to know about evolution and ecology and it's understandable by... | [
"Could you go into more depth on one of the more likely theories perhaps? How do things like this just happen?"
] |
[
"Can we predict coronal mass ejections?"
] | [
false
] | null | [
"I'll take your question to be 3 parts.",
"Can we predict coronal mass ejections?",
"Generally speaking no. We have a very difficult time definitively predicting that an active region on the Sun will produce flaring activity and/or coronal mass ejections beforehand. Our best indicator is whether the active regi... | [
"destroy the electrical systems of a large number of cars",
"How would this happen if a car is not connected to a long conducting cable?",
"close to a \"doomsday\" scenario. ",
"The case study of the 1989 solar storm is probably informative here.",
"It was estimated to be about 60% as strong as the dreaded ... | [
"It depends. I believe it might be possible to predict them a few hours to a few days beforehand. But anything more will not work . For example people believe ",
"Carrington level event",
" happens once in 150 years so. But there isn't much data to prove that and there isn't much consensus (I was at a talk abou... |
[
"Will a new planet eventually form in our solar system's asteroid belt?"
] | [
false
] | [deleted] | [
"No. Also the mass of all the asteroids together is ",
"about 4% of the mass of the Moon",
" - pretty small. "
] | [
"About one third of the mass of the asteroid belt is contained in ",
"one object",
"."
] | [
"The asteroids are too spread out as well as not enough. For a new planet collisions would have to be common. "
] |
[
"Matter can be converted to energy. Does the opposite also happen?"
] | [
false
] | I know of many processes where matter is converted to energy, but I can't think of a single one where the opposite happens. Is the amount of matter in the universe in a constant decline or is energy turned back into mass somewhere? It seems like a very basic question so excuse me if this is common knowledge. I honestly... | [
"Let me clear a misconception: energy is not a thing, energy is a number that tells you about a \"conserved quantity\" in your system. You cannot \"create\" energy, energy is there all along.",
"What E = mc",
" tells you is this: when you have a particle at rest, it has an intrinsic amount of energy, just by th... | [
"Just to be more precise, the full equation is actually:",
"E",
" = (mc",
" )",
" + (pc)",
"in which ",
" stands for momentum. When you have a reaction of this kind, you start with a massive slow particle, ",
", and end up with a fast light particle, ",
". You do not create energy. ",
"Your confus... | [
"Thanks for you answer. And happy cake day!"
] |
[
"If a normal/healthy person started to take anti-depressants, what would happen? Would they feel happier then normal?"
] | [
false
] | null | [
"Anti-depressants aren't pills you take that make you happy. They are not like fun drugs where you pop a few and get all dopey. They work to regulate and restore balance to a chemical imbalance in the brain, over a long period of time. Usually AD have to be take for about 6 weeks before they even start to have the ... | [
"Depression involves a decrease in positive emotions and an increase in negative emotions ( ",
"source 1",
", ",
"source 2",
" ). Antidepressants, when effective, reverse these effects, sometimes increasing positive emotions and consistently decreasing negative emotions ( ",
"source 1",
", ",
"source ... | [
"Not sure where you're getting your info from, but Xanax isn't a selective serotonin reuptake inhibitor, it isn't even an antidepressant. ",
"It's a benzodiazepine, basically a mild tranquilizer used to treat anxiety disorders. It would not be used to treat depression, since it is actually a depressant itself, an... |
[
"Heart diseases - what is the difference between hypertrophy, cardiomyopathy, cardiomegaly and dysplasia?"
] | [
false
] | I understand that heart muscle is thickened/enlarged in all these cases, so why are there so many distinctions? Would anyone explain to me the differences in the simplest possible way? I got interested in this, but I'm a total layman in medicine or biology. Thank you. | [
"Hi, these are all terms that may be used to describe varying heart adaptations and/or pathologies",
"Hypertrophy: this technically refers to excessive growth of an organ. For the heart, this typically refers to extra muscle growth. This can lead to decreased cavity size due to thickening of your hearts walls (co... | [
"Adding on to this: ",
"Cardiac Hypertrophy isn't necessarily bad. You mention two types, and endurance exercise induced Eccentric Cardiac Hypertrophy is not only about the dilation of the heart cavities, but also proportional increases in left ventricular wall thickness. Together, these enable significant increa... | [
"Spot on. Eccentric hypertrophy is commonly seen in aerobic athletes, concentric in weight lifters, and a combination of concentric/eccentric for athletes who do both (most common). This can be dangerous in rare pathological circumstances but is otherwise a normal and healthy physiologic response to exercise."
] |
[
"What happens when a photon hits an electron but doesn't excite it?"
] | [
false
] | [deleted] | [
"'Hitting' an electron isn't really a thing, neither the photon or electron are small hard spheres. ",
"The photon is a change in the electrical (and magnetic) field and the electron is a charged particle that responds to it. The end result can be that the photon just passes without any change, that the electron ... | [
"It's not little pieces of something. (Neither is an electron, which is also a fundamental particle) There's no 'shell' around these things. They're particles, but in the sense of quantum mechanics, which doesn't imply they have a size of its own. "
] | [
"It's not little pieces of something. (Neither is an electron, which is also a fundamental particle) There's no 'shell' around these things. They're particles, but in the sense of quantum mechanics, which doesn't imply they have a size of its own. "
] |
[
"Why does cancer form in organs but not in your arms or legs?"
] | [
false
] | I've never heard of leg cancer or finger cancer. Maybe they exist but ya idk. | [
"There are. Bones have things like osteochondromas, osteoblastomas, osteosarcomas, ewing's sarcoma, osteiod osteoma, chondroblastoma, etc. Skeletal muscles have rhabdomyosarcomas. Smooth muscles have leiomyomas and leiomyosarcomas. Your nerves can get shwannomas. Your skin can get melanomas, basal cell carcinomas, ... | [
"Rhabdomyosarcomas can develop in the muscles, so potentially you could."
] | [
"Cancer forms in your tissues. You won't get \"calf cancer\" but you might get skin or bone cancer located in the lower region of your leg. Theoretically you could have abnormal cell growth and division anywhere in your body, but some cancers are more frequent than others. Which is why we often tend to relate cance... |
[
"Why can a probability distribution (like the Cauchy distribution) not have an average, and what does that mean in the real world?"
] | [
false
] | I'm a computational mathematics student whose finishing my master's degree, so I'm actually pretty familiar with the math of the Cauchy distribution not having an expected value or a variance, but I can't really interpret what that means in practice. To simplify, let's consider a random variable X whose probability den... | [
"As your number of drawn values increases, the average would converge if there was a defined expected value. That's kind of what an expected value is, the expected mean is an ensemble-averaged quantity. So if you have numbers drawn from a true Cauchy distribution, then the more you draw, the average will not conver... | [
"So-called \"power law\" distributions like this one come up quite a bit in practice, especially in some models of node sizes of social networks. ",
"The idea is that there could be a probability distribution describing the numbers of friends an average person has that does not change much as the social network g... | [
"A bet is considered fair when one party pays the expected value to receive the random variable. By cutting off the tail of the Cauchy distribution you can see that its mean must be greater than any positive number, in other words it is not merely undefined but infinitely large. Therefore if X is a sampled value, f... |
[
"Can cats/dogs recognize other animals in photos?"
] | [
false
] | Inspired by post. I get the feeling we're anthropomorphising it, but who knows? | [
"There is some weak evidence for dogs recognizing faces from photographs:",
"Study focusing on visual tracking and controlling for animal's background ",
"http://link.springer.com/article/10.1007/s10071-013-0713-0?no-access=true",
" ",
"edit: (",
"more detail on this study",
")",
"Study with indirect ... | [
"I'd like to see more studies on crows and magpies as well, also targeting raccoons and flying foxes. I didn't find any research on these animals."
] | [
"The New York Times published an article a few years ago about facial recognition in crows, and also group memory of recognized 'enemies'. The story is here: ",
"http://www.nytimes.com/2008/08/26/science/26crow.html?_r=0",
" and comes from the University of Washington. Not sure if there is a corresponding artic... |
[
"Is the vascular system of women better than men?"
] | [
false
] | Considering that they have to replace the lost blood periodically, is their vascular system flush with fresher blood? I heard that it is good to donate blood because it stimulates the marrow into producing more blood. | [
"I heard that it is good to donate blood because it stimulates the marrow into producing more blood.",
"Your body is constantly producing and destroying blood cells on a daily basis. "
] | [
"I heard that it is good to donate blood because it stimulates the marrow into producing more blood.",
"It's good to donate blood because it saves lives. But a healthy person's bone marrow will be constantly producing blood cells no matter what. A red cell only lives about 3-4 months, so they are constantly being... | [
"is their vascular system flush with fresher blood?",
"Not really, no. Women who have menstrual cycles are more likely to have iron deficiency anemia, though.",
"I heard that it is good to donate blood because it stimulates the marrow into producing more blood.",
"That's wrong and I've heard smart people say ... |
[
"How does light transfer energy without having mass?"
] | [
false
] | Since it's something we deal with everyday it feels intuitive that sunlight causes things to warmup. How does it do that exactly? How does something with no mass effect things that do? | [
"Light is an electromagnetic wave, which is essentially an electric field and a magnetic field that dance around around each other, and self sustain each other, as the wave moves through space. ",
"These electric and magnetic fields actually carry energy in them! This is demonstrated better nowhere than the capac... | [
"The whole \"relativistic mass\" thing is an outdated way of looking at things. I believe that the preferred way of thinking these days is that photons have no mass, but they ",
" have momentum."
] | [
"The whole \"relativistic mass\" thing is an outdated way of looking at things. I believe that the preferred way of thinking these days is that photons have no mass, but they ",
" have momentum."
] |
[
"Do human antibodies bind to animal cells? I see that in ANA tests they use rat cells. are they transgenic mice? or just regular mice."
] | [
false
] | null | [
"The body only really makes antibodies against stuff it has actually encountered. So a human would only have antibodies against animal stuff that has come into contact. Under normal circumstances that might be a bit of hair and the like, rather than more intact/living cells or their nuclei (what ANA tests for).",
... | [
"Wait but they used to use animal cells? ",
"https://www.hopkinslupus.org/lupus-tests/lupus-blood-tests/",
" 'usually sections of rodent liver/kidney or human tissue culture cell lines' What I mean to say is, do human cells and rat cells share the same antigens. Thanks for replying btw"
] | [
"I don’t know about ANA tests in particular, but nuclear proteins in general tend to be highly conserved (I.e. similar across a wide range of species). This makes sense because the basics of DNA replication and RNA production are virtually identical across hundreds of millions of years of evolution. Wikipedia’s art... |
[
"Is our emotional response to certain colors caused by nature or nurture?"
] | [
false
] | [deleted] | [
"As in all things psychology, the answer is both. Take the color red for example. Researchers measured hormone levels of women every day for 1-2 months, took their picture, and independent people rated how attractive they were. They found that women wear red almost 2-3x more often when they're going through the fir... | [
"As in all things psychology, the answer is both. Take the color red for example. Researchers measured hormone levels of women every day for 1-2 months, took their picture, and independent people rated how attractive they were. They found that women wear red almost 2-3x more often when they're going through the fir... | [
"Women wearing red 2-3x more often while ovulating is interesting and possibly useful to know scientifically, etc., but it tells us nothing about genetic/environmental causation, because either genetic factors OR environmental factors could very easily be used to explain that. ",
"You would need results that are ... |
[
"Would there be negative side effects to de-desertification of the Sahara?"
] | [
false
] | null | [
"Of course. The Sahara and it's surrounding environment are far from lifeless and the ecologies are adapted to the current state. Furthermore,there are many unknowns in the way this might affect weather patterns around the world. There would most certainly be effects and they would be disruptive - not to say they w... | [
"You'd kill the amazon rain forest. Dust from Bodélé and elsewhere in the Sahara blows across the Atlantic Ocean and fertilizes the Amazon. ",
"http://m.theatlantic.com/technology/archive/2012/08/today-in-astonishment-the-amazon-rainforest-gets-half-its-nutrients-from-a-single-tiny-spot-in-the-sahara/260655/"
] | [
"This is along the lines of what piqued my curiosity. I understood vaguely that we kinda sorta thought sand storms actually spark hurricanes in the atlantic as well."
] |
[
"What gas has the strongest color?"
] | [
false
] | [deleted] | [
"Iodine",
" has a strong magenta colour as a gas. Scroll down for a photo. This is the first I could think of. "
] | [
"Could you explain further? What does \"strongest color\" mean, and in what way do gases \"have\" colors?"
] | [
"They do have colors. I just wasn't sure if you were referring to maybe absorption or emission spectra instead of reflection spectra or what have you. Ignore my silliness.",
"I don't have the requisite knowledge to answer your question, but I can tell you a few things you need to consider controlling for in a hyp... |
[
"What is the minimum number of sides on a rubik's cube that must be known, after randomizing, to successfully solve it?"
] | [
false
] | In the case of more than one unknown side, each unknown can either be opposite or adjacent to each other. | [
"Exactly half the possible configurations can actually be reached. If you know everything about every piece but one edge, you can deduce the orientation of that edge, but there's no information beyond that.",
"It may or may not be solvable with five sides known. You might have a green/red edge and a green/yellow ... | [
"Do you mean \"the smallest n such that for every legal Rubik's cube state, there exists n faces which provide enough information to determine a solution\", or do you mean \"the smallest n such that there exists n faces such that for every legal Rubik's cube state, these n faces provide enough information\"?",
"I... | [
"None, if it was randomized to solved (despite how improbable, that is the minimum)"
] |
[
"Can you get diabetes from eating sugar supplements."
] | [
false
] | The idea being that when you eat a sugar supplement, for example when drinking a diet fuzzy drink, your body produces and releases enzymes into the digestive system to break up the sugar molecules. But because these sugar supplements are not sugar and as a result do not consume the enzymes; The body reacts to the large... | [
"There's no known negative side effects in humans of ingesting a reasonable amount of artificial sweeteners. Type 2 diabetes is thought to be caused by environmental factors like diet, but it is related to having a large waist with lots of belly fat. It is characterized by an insensitivity to insulin, where the h... | [
"Show me the data. I'm willing to bet all you have is correlation. ",
"Fat people tend to drink diet soda, fat people tend to have diabetes."
] | [
"Yes, when I used the word supplement I actually meant replacement so that naturally occurring sugars would be replaced with artificial sweeteners.",
"English is not my native tongue, have mercy on my soul dear scientists."
] |
[
"Is it possible to build a van sized vehicle propelled by an electric motor powered by rooftop solar panels given present-day technology?"
] | [
false
] | It's a pipe dream but I've always wanted the ability to just get in a car and roadtrip to, for example, the Grand Canyon and not have to worry about paying for gas or a hotel room. I'm just looking for any possible way that I can have a vehicle large enough to fit a mattress in the back that I can drive around in power... | [
"This question is fairly common on this subreddit. I answered something similar ",
"Here",
". The specific result was that you need 35x the area of a normal car ",
" to get around 20hp. If you are willing to drive one hour a every day and a half, you can have ~20hp by covering the entire area of your car in s... | [
"covered in current tech solar panels to get around 20hp",
"To make matters worse, it can only get about five times better. Current off-the-shelf consumer single-junction PV is about 20% efficient at the upper end of the market. And you can't get more than 100%-- that's all the energy available for even a perfe... | [
"There was, but the panel was not large enough to run heat or a/c-- it only ran a small vent fan to circulate hot air out of the car.",
"Amusingly, when I tried to buy one here in Arizona in 2010 (seemed like a perfect fit for a sunny place with 125F heat), the dealership warned me against it because it's too hot... |
[
"What is the minimal amount of social interaction needed to not lose sanity?"
] | [
false
] | [deleted] | [
"I'm not an expert on this topic, but I spent 6 weeks with absolutely ZERO contact with humans years ago while camping in northern Alberta, Canada. (Note: I wasn't lost or stuck, I did this on purpose!)",
"By the end, I was having full conversations with myself, and even arguments. I was also having vivid dream... | [
"No. The only things I had were a 8'x8' blue tarp, a large axe, about 200 feet of nylon rope, a small metal pot (with a long handle), a fishing pole (with 3 hooks), a bar of soap, and 10 lbs of brown rice in a water proof container.",
"Clothing wise: A winter jacket (rated to -40C), three sets of wool socks and... | [
"Zero. Read ",
"The Island of the Blue Dolphins",
". It is a well written famous children's book based on the true story of an Aleutian woman stranded on her home island, alone, for 18 years. While she was not able to effectively communicate very well with anyone after the ordeal due to language barrier (the... |
[
"Can a central force produce different closed orbits?"
] | [
false
] | I saw on and was interested in the mechanics of a geocentric solar system. Could a central force produce two different closed curve orbits other than a circle and ellipse? Could an object subject to a central force orbit the source of the force on a cardioid, or any other closed curve, for example? | [
"The following statements should answer all of your questions.",
"In general, the bound orbits of a point mass in a central force field are not closed. (Note, however, that circular orbits do exist for all ",
" central force fields. ",
" See ",
"this post below",
" for some clarity on that point and click... | [
"Here's a nice web applet that lets you play with different central force laws. ",
"Demo for Newtonian gravity",
" (F = -GM/r",
"Demo for 2D harmonic oscillator",
" (F = -kr)",
"General demo",
"Enjoy!"
] | [
"The only central force fields for which all bounded orbits are closed are the potentials U(r) = kr2 (the simple harmonic oscillator) and U(r) = -k/r (Newtonian gravity) for some k > 0. In both of these cases, the bound orbits are ellipses. (So nothing exotic like rosette patterns.)",
"Is this related to the fact... |
[
"Why do we fall asleep when we are bored?"
] | [
false
] | null | [
"the question implies this is not the case and wonders why boredom makes someone who has gotten plenty of sleep tired and what purpose it serves"
] | [
"That's because the question is wrong. ",
"\"If you believe that boredom, a warm room, or a heavy meal causes sleep, you are completely wrong! If boredom, a warm room, or anything else seems to cause you to feel drowsy, you have a sleep debt and you need to be stimulated in order to stay awake.\""
] | [
"How do you know that the sleepiness comes from boredom and not prior sleep deprivation?"
] |
[
"Whenever I read a story about a school or something installing a windmill for the purpose of powering the building, I always hear something about selling the excess power to the power company. How exactly do they do this?"
] | [
false
] | I mean, do they just charge up batteries and send them over? Sorry if this is the wrong subreddit, figured this was my best bet. | [
"Typically a wind or solar system will be used to charge a bank of batteries for power on-site. These systems can be connected (by a professional!) back to the grid, and when your batteries are fully charged and your source of electricity is generating more power than you need, your meter will actually run backward... | [
"Many properly constructed solar houses actually produce more energy than they need and the owner of the home actually recieves a check from the power company.",
"What typically happens is the power generated by the mechanical motion of a turbine or from a solar array is just wired into the grid, allowing power t... | [
"Net Metering",
" allows electricity generated onsite to run the electric meter backwards if more is being generated than is needed (and thus being sent to the grid as a result). When the power company comes and reads the meter at the end of the month, they'll credit you the appropriate amount of money if the met... |
[
"Would a live stream of a clock travelling at near the speed of light appear to be ticking slower to someone stationary on earth?"
] | [
false
] | Or say an astronaut is going 25,000 miles per hour (I think that's the fastest any human has travelled). He has a stopwatch that shows time to many decimal points and a camera pointing at the watch. To an observer on earth watching a stream from the camera would the watch appear to be ticking slower than a similar watc... | [
"Yes, although at 25,000 mph, just barely.",
"Let's instead look at a clock travelling .866c with respect to us. If we kept a telescope trained on that clock, and we kept an identical telescope next to our telescope, we'd notice that our clock ticked twice for every single tick of the travelling clock. Time is ... | [
"we'd notice that our clock ticked twice for every single tick of the travelling clock.",
"As it happens, this isn't what you actually ",
". The Lorentz factor tells you how much time \"really\" passes on the two clocks, ",
" accounting for the speed of light delay in the signal. To answer the question of wha... | [
"Fair enough. I should have said, \"moving tangentially.\""
] |
[
"When neurons are transmitting messages, why don't the messages go through each and every neuron exactly how it was received initially?"
] | [
false
] | Sorry if the title doesn't make too much sense, I'm learning about action potential in Psychology and don't understand the transmission of the messages. What I do get is how the messages travel through the axon via chemical polarization and depolarization, albeit some of it is a bit fuzzy, and from what I've learned on... | [
"Your general idea of how an action potential works seems correct. A chemical message in the form of a neurotransmitter signals the dendrite of a nerve to begin an electrical signal (in the form of ions flowing across the neuron's membrane). If that signal is adequate (close enough to the axon hillock or followed b... | [
"I'm unclear what you mean by \"Neuron arrangements\" but I'll interpret as how the neurons are connected to each other in space. The answer is, in as far as we know yes. How neurons are wired together through the formation of synapses, the strengthening of synapses or the weakening of synapses, in what is termed s... | [
"An axon hillock is the point of the neuron at which the axon connects to the cell body.\nTo expand on the relevance of the action hillock in this discussion:",
"Action potentials travel through a neuron in the form of an electrical charge. The charge across the neuron is not equal. Input from the axons of other ... |
[
"If space is expanding, are more units of space being made, or are they getting \"bigger\"?"
] | [
false
] | My knowledge of quantum field theory is very tenuous and high-level - I have basically no clue about the underlying math here - but my rough understanding is: So if space is expanding, are more quanta of space being created? Or is existing space stretching in some way? IE - is the ratio of quanta of space to the size o... | [
"If you draw a sphere in space by putting test masses (at \"rest\"), or galaxies, all around its surface, then as the universe expands there are more cubic meters inside the sphere as time goes on.",
"But, a few remarks on your other comments:",
"- We do not as yet have evidence that space itself is quantized. ... | [
"Jumping in on that last point - the current fashion in quantum gravity is to consider the total number of bits of information that can be stored in a finite volume of space (which is surprisingly thought to be finite even if space itself is not quantized). As a given volume of space expands, more information can b... | [
"I love arguments based on information theory - thanks for adding that! But surely the number of bits that can be added depend on the \"size\" of the bit, and it seems like you're assuming that is fixed in meters, yes?"
] |
[
"How is the \"power\" of dish soap measured? How can a company claim one of its products is \"3 times as powerful\" as another one?"
] | [
false
] | null | [
"Soap works by forming something called a miscelle. It's basically a ball where all the dirt and grime sticks to the middle, the hydrophobic part, and the water touches the outside hydrophilic part. When you use soap, you're not killing any bacteria or dirt, You're just making tiny dirt bubbles and washing it away.... | [
"...you're not killing any bacteria...",
"Well, you absolutely can and will kill bacteria with a surfactant like soap. Not all bacteria are equally susceptible, but many are.",
"I would say that if soap has the ability to make more miscells, as it has more lipids, it's likely to be a better",
"Increasing lipi... | [
"Soaps are basically surfactants. They remove dirt by lowering surface tension of water and forming emulsion with dirt. There are various parameters of soap efficiency. In case of dish soaps, the efficiency is usually determined by testing the amount of dishes cleaned by a particular amount of soap, foam test, CMC,... |
[
"What causes an allele to be dominant or recessive?"
] | [
false
] | null | [
"The dominance of different alleles of a gene is largely determined by the nature of the protein that it encodes. For example, defects in structural proteins generally manifest as dominant traits because being heterozygous results in defective protein synthesis, which disrupts the native healthy protein. On the oth... | [
"the genetics of eye color is actually quite complex, at least 15 genes are involved",
"Although, for a thought experiment, lets assume its one gene:",
"BB = make brown pigmnent",
"Bb = make brown pigment",
"bb = make no pigmnent (unpigmented irises are blue)",
"In this case, blue eyes are classically rec... | [
"Since this is a science thread, let's not call alleles genes.",
"Genes cannot be dominant/recessive, but alleles can. Similarly, you cannot have or not have a gene, but you can have one allele or another. "
] |
[
"Do we perceive in 1, 2 or 3 dimensions?"
] | [
false
] | I read somewhere that each of our eyes see a 2D image and the brain combines those images that are from different perspectives to create a 3D representation via adding perception of 'depth'. This seems to make sense as illustrated from this . If i look at the corner a, i can intuitively say it forms a right angle. Howe... | [
"In regards to your diagram, the only reason we can perceive that angle as 2 \"different\" angles is due to three-dimensional perspective. Perspective B is NOT a 2 dimensional image. You're viewing it from a different place of reference, indicating 3 dimensional perspective. True 2 dimensional perspective would onl... | [
"Thanks for the response.",
"as in, the light emitted or reflected from things in the world around us enters our eyes and is focused on the retinas of our eyes, which are 2-D structures. ",
"What do you mean the retinas are 2D structures? are you saying they don't have width? ",
"The rods and cones in our re... | [
"| What do you mean the retinas are 2D structures? are you saying they don't have width?",
"They line the inside of the back of the eyeball: two dimensions. It's not like the whole\neyeball is filled with layer after layer of photoreceptors or anything, so not three.",
"| So light is hitting this 2D surface (ou... |
[
"Would the night sky look very different on a planet orbiting proxima centuari compated to ours?"
] | [
false
] | null | [
"Alpha Centauri would be extremely prominent at magnitude -7 or so. Not as bright as our Moon but still dominating the night sky when visible, and clearly visible even during the day (assuming similar or better atmospheric conditions).",
"At a typical separation of around 0.1 degrees a human eye could see it as b... | [
"It would depend a lot on the exact stars, but only moderately different. eg: there's a new fairly bright star somewhere around Cassiopeia (Sol), and Sirius would have moved a lot, but Betelgeuse very little and Deneb not at all."
] | [
"One significant difference is that the Sun would appear as a 1st magnitude (+0.5) star in the constellation Cassiopeia. Observers there would see it as the brightest star in the W of Cassiopeia, which would appear only slightly distorted from its appearance on Earth.",
"Sirius, the brightest star in Earth's nig... |
[
"Question on the motion of dark matter"
] | [
false
] | [deleted] | [
"Well, it interacts gravitationally. So it can be attracted by the gravitational field of, for instance, a billion stars."
] | [
"There's nothing in principle saying there couldn't be, but it depends on what exact particle the dark matter turns out to be. If there were, then in all likelihood most of it would have long ago annihilated away, just like the rest of the antimatter did."
] | [
"The smart money is on dark matter consisting of the lightest neutralino, which theory predicts should be a Majorana fermion — that means it's its own antiparticle. If that's the case then yes, neutralino-neutralino annihilations can occur. But the rate of annihilations will be much less than it would be for, say, ... |
[
"How legitimate are the results of Harvard's \"Eating ANY red meat leads to higher risk of premature death\" study?"
] | [
false
] | null | [
"Actually, that looks awfully solid. The biggest red flag to look out for with these sorts of broad cohort studies is any kind of variable between the groups that are extraneous to the one being tested. They controlled for a ton of variables:",
"We simultaneously controlled for intakes of total energy, whole grai... | [
"It's a good study for how large it is. I'm not necessarily debating their findings, but self-questionnaires on diets are commonly flawed (especially in a case like this where diet questions were taken so infrequently). ",
"(speculation) Additionally, if you think about the average diet, those that are unlikely t... | [
"Did they control for total carbohydrates and refined carbohydrates? ",
"Most red meat in North American society comes with a hearty helping of carbohydrates. You wont see many steaks without potatoes, or burgers without buns. It would be interesting to see if they were able to control for this.",
"I would read... |
[
"Store data in living DNA?"
] | [
false
] | Is there any wasted space in the DNA code of living things? and Given a file format that used DNA, could one for example, store a message in DNA that would propagate to offspring? | [
"Is there any wasted space in the DNA code of living things?",
"Yes, but not as much as you think. ",
"The Encode Project",
" recently found that about 18% of your DNA regulates the 2% of your DNA that manufactures proteins. And this definitely isn't the complete picture. While we do have a lot of junk that i... | [
"A good estimate of DNA mutation rate is 2.5 mutations per 10",
" bases per generation. Over evolutionary time (millions of generations), of course, there would be an unacceptable loss of integrity in any single copy. ",
"However, if you inserted your message into lots of species with long generation times (not... | [
"There are large segments of the genome (up to 90%) that don't code for expressed genes, but the exact biological role of this \"junk DNA\" isn't fully known.",
"Craig Ventner, who created an organism with an artificial genome, ",
"encoded a lot of information",
" in the genome of a bacterium."
] |
[
"Why is it so drastically easier to tear a piece of tape, or a bag of chips once it already has begun tearing?"
] | [
false
] | Just a thought that popped into my head while messing around with some tape at work today. | [
"Here's a good article: ",
"http://en.wikipedia.org/wiki/Stress_concentration"
] | [
"This is also the case for faults on the earth. If you have a homogeneous material (well, as homogeneous as it gets on Earth), then you will be spreading out the stress throughout a specific area of the tectonic plate. However, once you introduce a fault (due to either a previous weakness being exploited, or the st... | [
"The stress will concentrate at the ends of the propagating fracture."
] |
[
"How can there be matter (low density plasma) in outer space? Why doesn't gravity pull it towards stars or planets?"
] | [
false
] | null | [
"The answer is simpler, with no need to invoke cosmology or general relativity.",
"If you have a gas in a potential (such as one caused by gravity), and each gas particle is undergoing thermal motion, there will be a distribution in gas density where gas is more likely to be found deeper in the potential, with ve... | [
" but I think I have enough background knowledge to help here.",
"First, the universe is not at equilibrium. It was once thought that eventually everything either a) had enough kinetic energy from t=0 to continue forever [that is, the universe was expanding beyond the escape velocity of the universe itself] or th... | [
"The interstellar medium is mostly plasma, and it generally orbits around the Galactic center in more or less the same way that stars do. It ",
" being pulled by gravity. Individual stars' gravity is pretty weak outside of their immediate system, and they generally have stellar winds that push gas away as well."
... |
[
"Some of the spacecraft rendezvous have been compared to firing a rifle on the east coast and hitting a small target on the west coast. What would comparable with New Horizons?"
] | [
false
] | After 9+ years and X millions (or billions) of miles traveled New Horizons will end up within just a few thousand miles of the surface of Pluto. What would be a comparable accuracy scaled down to a a distance/accuracy on Earth? | [
"The goal in the New Horizons mission is to hit a region that's ",
"60 miles by 90 miles",
" at a location that's about ",
"32 AU",
" or 3 billion miles from Earth.",
"Hitting that region at a distance of 3 billion miles is like sending something from NY to Paris and having it land right in the recipient'... | [
"Thanks, that is the type of analogy I was thinking of."
] | [
"I can assure you NH ",
" perform a gravitational slingshot with Jupiter and the Earth-Jupiter segment was ",
" straight (though pretty elliptical)"
] |
[
"If future data from the LHC and ILC suggest that our universe is metastable, what does that mean for the future of the universe?"
] | [
false
] | 1) What does "metastable" mean in comparison to unstable and stable? Why is this related to the properties of the Higgs Boson and Higgs Field? 2) If it is metastable, what kind of event could cause it to suddenly want to seek a lower energy state? 3) How fast would this "new physics" bubble expand once it reached a... | [
"While the previous comments give some partial answers, there are still some unanswered questions in your post, so let me jump in. ",
"First, the metastability of the vacuum is ",
". As you might know, the Higgs field is a scalar field which means that it is described by some number at every point of spacetime... | [
"All of this is very fun speculation, but it's just speculation based on our current models of the universe, which are well understood to be incomplete. Still...",
"1) It means roughly what you probably think it means - it's in a stable configuration but there are other potentially stable configurations it could ... | [
"Thanks for the great explanation in how the Higgs Field is related to this!"
] |
[
"Is there currently a reliable way to extract or isolate DNA in a prokaryotic cell without damaging it?"
] | [
false
] | [deleted] | [
"yes. either shearing or sonication will break up cell walls in the presence of a detergent. then using correct buffers, it is possible to solubilize dna molecules while precipitating out other cellular material and separating solubilized dna from cellular debris by centrifugation. once dna is isolated, it can ... | [
"Did you mean without damaging the DNA, or without damaging the cell?"
] | [
"Without damaging the DNA or without damaging the cell?",
"Anyway, there's a technique called SCODA that uses rotating electric fields to isolate DNA. It's pretty effective."
] |
[
"If I were to make an radio transmitter that broadcast at between 430 and 790 THz, would it emit light that I can see?"
] | [
false
] | null | [
"Electromagnetic waves at those frequencies are no longer called radio waves, so this wouldn't be a radio transmitter; it would be something that emits light. ",
"Radio and light (and microwaves and IR and UV etc.) are just names we give to different portions of the electromagnetic spectrum. For example, if you... | [
"Pretty snobby for being wrong.",
"To be fair, technically you are correct, it would emit light, thus making it \"a lightbulb\". However, the mechanism behind how and why light was emitted would be completely different. It would be novel, not like any light bulb today. In short, you completely missed the point of... | [
"Pretty snobby for being wrong.",
"To be fair, technically you are correct, it would emit light, thus making it \"a lightbulb\". However, the mechanism behind how and why light was emitted would be completely different. It would be novel, not like any light bulb today. In short, you completely missed the point of... |
[
"How long would it take to hard-boil an egg on Mount Everest?"
] | [
false
] | [deleted] | [
"The egg requires heat to be cooked, it doesn't actually boil. Boiling water is a lower temperature when it is at a lower pressure, so the egg would exist in lower temperature water, so it would cook slower or not at all depending on the pressure."
] | [
"The increased altitude won't (shouldn't) really affect how long it takes to cook the egg, merely whether it is possible to cook the egg at all. It simply boils (heh...) down to asking:",
"As you increase altitude, the pressure at which liquid water boils will fall. You can see this on a ",
"phase diagram of wa... | [
"Pressure cookers are generally set to about 14 PSI, so you could hard boil an egg in a pressure cooker at any elevation, assuming you can provide the heat needed. An electric hot plate should do the job at near vacuum. Will be an interesting experience opening it though."
] |
[
"Does a fetus dream?"
] | [
false
] | null | [
"I googled because I thought this was interesting and it seems like the answer would be yes, since we typically define the dream-state as occurring during ",
"REM-sleep",
". I'm not an expert in this though "
] | [
"I got the same thing. 85-95% sleep, and spdcukstion",
"What I did find interesting is that a fetus will lick the uterine wall and touch its hands and the umbilical cord."
] | [
"So is a fetus conscious in the womb? I always assumed it was asleep or something."
] |
[
"What happens when water vapor evaporates from a cloud?"
] | [
false
] | null | [
"First of all, water vapor can't evaporate. It's already vapor. Get it? Clouds are made of droplets and crystals (ice) or at least that's the white thing you see when you look up at the sky. \nIt just goes back into the air. Temperature does not change as a result of this. Rather, water drops/crystals turn into wat... | [
"Thank you for the response! I was asking myself this question a few days back, and I realized that I did not know the answer. I suppose I did not consider the idea that water vapor can not evaporate. Thanks again!"
] | [
"It evaporates and the humidity increases in the surrounding air. This will also cause a slight decrease in the temperature of the air, but like, a tiny fraction of a degree C since clouds are very low density structures."
] |
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