title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Are carbon fiber implants in the body safe and feasible?"
] | [
false
] | I was talking to someone the other day and I said why not have carbon fiber implants in the body e.g. hip implant because carbon fiber is strong and low weight among other things (like resistant to high temperatures, etc..) The person I was talking to said that would be a terrible idea and dangerous? I assumed it had ... | [
"I'm sure if it was dangerous there would not be companies making them. ",
"Like this one"
] | [
"Although by the look of the images on that website, they don't seem to show up on x-ray very well. Which for ongoing monitoring of implants, is Not A Great Thing.",
"Temperature resistance isn't particularly important (except for maybe the sterilisation process before implantation). Weight also isn't AFAIK that ... | [
"Because companies never sell things that are dangerous."
] |
[
"Why when we stare at a negative image, then blink, do we see it in colour?"
] | [
false
] | Saw some on Reddit a few days ago, whereby if you stare at a spot on a negative image then blink/look at a white wall you can see it in colour. | [
"I am a computer vision PhD student, and I study human perception as part of my work.",
"What you are describing is a very interesting use of the ",
"afterimage",
".",
"Short, digestible explanation:",
"Your iris, cornea and lens act like a camera lens to project the image your eye is facing onto your ",
... | [
"My understanding was that photopigment bleaching is only an indirect component of why you perceive afterimages. Rather, fatigue of opponent-process (parvo) ganglion cells (R+/G-, G+/R-, Y+/B-, Y-/B+) that receive their inputs from the cones and bipolar cells are what are responsible for the afterimage. ",
"EDIT:... | [
"because your eyes get use to inputs (like the color of light) and slowly lose sensitivity to it. ",
"When you look away from the Negative image, the lowered sensitivity to the negative color produces the Illusion of a normal color image on a white wall"
] |
[
"Do common colds or flu strains leave permanent damage similar to what is being found with CoViD-19?"
] | [
false
] | This post has CoViD-19 in the title but is a question regarding the human body and how it handles common colds and flu strains which are commonly received and dealt with throughout a normal life. Is there any permanent damage caused, or is it simply temporary or none at all? Thanks! Edit: I had a feeling common colds a... | [
"Influenza can cause heart problems. Do you know what the most effective preventive treatment for a heart attack is? Influenza vaccination. ",
"There is a large body of observational and clinical trial evidence that shows that influenza vaccine protects against AMI. Estimates of the efficacy of influenza vaccine... | [
"There's a generally held strong suspicion that a lot of autoimmune chronic disease is cause by as yet unidentified viruses or bacteria - Most likely ones we're already aware of. There's a Nobel prize in finding the links.",
"For example there's a few big trials at the moment looking at the link between dementia... | [
"I was gonna make a pile but I'd like to just add on your your pile if that's okay.",
"Influenza vaccination reduces all-cause mortality in heart failure patients.",
"Significant association between respiratory infections, especially influenza, and acute myocardial infarction.",
"Of course, heart attacks caus... |
[
"Can multiple parallel procedures be simulated as a one?"
] | [
false
] | If you have an abstract system which runs a number procedures, naturally with possibility of being out of sync, is it possible to emulate the evolution of the whole as a single procedure. I just go idea that one could maybe encode the whole system as an evolution of one-dimensional string. Please grant any notable prop... | [
"Whether you can do this in any meaningful way really depends on what you're trying to do. Yes, it's possible to ",
" multiple parallel processes, but in doing so you must pick one particular serialization out of many possible serializations. If by ",
" you mean \"explore the total range of possible behaviors\"... | [
"thanks! a simple-minded person could have just said the outcome, \"only in small scales\" but the massive explanation you granted is massive but even greater in meaning!",
"have a good day!"
] | [
"Your question is one of the fundamental questions posed in ",
". In a distributed system, multiple processors execute tasks in parallel, and questions about their operations like the following need to be addressed:",
"There are sets of rules that, when all nodes in the system adhere to, answer this question. T... |
[
"Does polyoxymethylene block infrared radiation?"
] | [
false
] | Question came up today at work & seems to be ungoogleable. | [
"It will block infrared radiation the same way that small organic molecules do, certain frequencies will be blocked but it will likely be transparent to the majority of the IR spectrum. I can't find a specific plot for that polymer but it will likely look similar to ",
"dimethyl ether",
" as the primary bonds ... | [
"Here is a source for an ",
"FTIR spectrum",
".",
"It appears that Polyoxymethylene is \"translucent\" in the IR range, but I'm not sure exactly how one would interpret something like this. I guess we could say - it mostly doesn't block infrared radiation."
] | [
"page 89. It is not translucent, it has several peaks."
] |
[
"So I just heard gravity is weaker than some other forces. What does that mean exactly?"
] | [
false
] | I'm watching a documentary on Netflix called Particle Fever. It's about the hadron collider and how it was built or the first time I turned on.. I'm not sure yet and I'm sorry my ignorance is shining through. I wish I knew that which I spoke of. But anyway. One of the scientists here was talking about asking the real q... | [
"Don't mind me, just adding an additional detail that I think is helpful. :)",
"A simple test you can do to prove this to yourself: find a magnet and some paper clips. Use the magnet to pick up the paper clips. Clearly, you are overcoming the weight of the paper clips using the E&M force.",
"It's worth noting t... | [
"That's a little unfair to gravity. ",
"I can't say I see how it is. I'm talking about directly comparing the size of the ",
"coupling constants",
", and the gravitational coupling constant is something like 10",
" times the strength of the electromagnetic coupling constant.",
"If the mass of the Earth w... | [
"There are four fundamental forces: The two nuclear forces, electromagnetic force, and gravity.",
"When we say gravity is weak, it is in relation to those forces. Gravity is the weakest of the four. A simple test you can do to prove this to yourself: find a magnet and some paper clips. Use the magnet to pick up t... |
[
"Do people with over-active immune conditions (like allergies, asthma, or IBD) actually have immune systems that fight off normal infections better, due to their hyper-vigilance?"
] | [
false
] | curious whether any clinical tests have been done. do they fight off colds and influenza any better for example? | [
"No. ",
"Your immune system is highly specific. Every lymphocyte white blood cell you have is specific for ONE thing. When a white blood cell is activated, and sees what it is specific for, it clones itself to make thousands of copies. Then the clone army attacks that one thing.",
"If you have an auto-immune di... | [
"How does this explanation jive with the ",
"hygine hypothesis",
" and ",
"helminthic therapy",
"?"
] | [
"The immune system is far more complex than simply lymphocytes. Although lymphocyte specificity addresses the original question, there are other factors at work for the hygiene hypothesis and helminthic therapy, neither of which have been fully explained.",
"The TL;DR of both concepts is that they generally deal ... |
[
"If interaction with the Higg's Field is defined by mass, does an object with more mass therefore have more interaction with the Higg's Field?"
] | [
false
] | thanks! | [
"Yes. From page 5 of pdg.lbl.gov/2010/reviews/rpp2010-rev-higgs-boson.pdf",
"\"The SM Higgs couplings to fundamental fermions are proportional to the fermion masses, and the couplings to bosons are proportional to the squares of the boson masses.\""
] | [
"Yes"
] | [
"There are now even experimental results that support this relationship. I really happen to like ",
"this summary plot",
" which shows the coupling strength for fermions, or an equivalent quantity for bosons, as a function of the mass of the particle that couples to the Higgs."
] |
[
"What force caused the planets to start spinning about their axis?"
] | [
false
] | What caused the spin of the earth in the first place. | [
"Everything spins. Essentially because everything is not ",
" uniform, as it falls together, it doesn't fall straight \"toward\" the center. It falls, but misses passing through the center and shoots off into an orbit. This is true of stuff falling into place around the sun (forming planetary orbits) and stuff fa... | [
"The moon does spin. It's period is ~28 days, the same length of time it takes to orbit us. If the moon didn't spin the same side ",
" always face us. ",
"Edit: We call such objects ",
". It's my understanding that space stations are largely the same as the moon in this regard but they maintain oreintation ar... | [
"satellites and the ISS have thrusters to carefully control the spin to make sure solar panels are in the correct place and docking with other vehicles."
] |
[
"Dark Matter Deniers: Is there room to doubt the existence of dark matter?"
] | [
false
] | [deleted] | [
"We have pretty good evidence of dark matter from a variety of sources. I could list them all, but I'd pretty much be copying from ",
"the wiki",
" anyway.",
"What we think we're looking for is a particle that only interacts weakly. We have an example of a particle that does that, in the neutrino (excepting c... | [
"If dark matter is defined to be gravitating, dynamical degrees of freedom that are independent of ordinary matter (i.e. known standard model constituents), then objects like the Bullet Cluster are convincing evidence for dark matter. Gravitational lensing clearly identifies sources of gravity that are dynamically... | [
"One assumption, that there's a particle we haven't yet observed, explains an awful lot of data, including predictive power (like in the CMB spectrum matching predictions based on dark matter models we have from galaxies and clusters).",
"The other hand is that General Relativity, which has worked remarkably well... |
[
"What makes heat a more highly disordered form of energy than say potential energy?"
] | [
false
] | null | [
"This really comes from the defintion of heat. Heat is energy whose precise origins we aren't paying attention to. Have one billiard ball collide with another, and we'll talk about the energy transfer in terms of kinetic energy. Have two gases come in contact with each other, we'll talk about the energy transfer... | [
"I always like thinking about statistical quantities in terms of their physical processes. ",
"Gas pressure, for example -- an average of the momentum transfer from individual particles colliding with the surface at various angles and speeds, producing a net effect. I think it helps to break these things down to ... | [
"This is an explain it like I'm 5 approach:",
"Heat can go many directions, potential is defined to go into one."
] |
[
"Do electrons actually move through a conductor?"
] | [
false
] | I've been watching some physics videos, and most of the time electricity/current is represented as particles (electrons?) moving through a conductor, like copper. However, I've recently "learned" that electrons barely move in conductors, it's only the electromagnetic waves that move significantly. Close to the speed of... | [
"Electrons always undergo thermal motion, so they're moving about randomly quite fast, but when no current is flowing the thermal motion all cancels out; the mean electron speed is on the order of kilometres per second (at room temperature) but the mean ",
" is zero.",
"When a current is flowing this means the ... | [
"The simple answer: Electricity is energy. An electron is just one particle. Electricity can travel at near the speed of light. I've read that the electrons themselves actually only move at about an inch in five minutes. \nHere's how that works. Imagine a long tube full of ping-pong balls. Push insert a ball in one... | [
"so the electron is just a vessel for electric energy? Kind of like buoys in an ocean?"
] |
[
"Any books suggestions to start out on understanding physics?"
] | [
false
] | null | [
"It depends on whether you want to actually learn physics or read a collection of interesting facts."
] | [
"It is a little old, but I always liked \"A Brief History of Time\" by Stephen Hawking."
] | [
"I was going to suggest this same book. Great read."
] |
[
"How Can I Support Stem Cell Research?"
] | [
false
] | [deleted] | [
"EDUCATION EDUCATION EDUCATION!!!",
"Honestly, I'm sure any and all of us scientists on here could write out a million things, but it all comes down to educating the general populous.",
"General info on stem cells:\n-The embryonic stem cells are harvested at the stage where they are called 'blastocysts' at and ... | [
"I have read articles about how judges extend or deny stem cell research phases, congress banning or passing bills pertaining to stem cells, Obama lifting the stem cell research ban, etc.. At the risk of showing my own ignorance; what affect does the general populous have on stem cell research?",
"What are the is... | [
"The issue that the public has comes to funding. The NIH, NSF, and other federally funded organizations have to follow strict rules when it comes to giving grant money out. When the \"stem cell ban\" was in place, you could not use ANYTHING procured with federal funds for embryonic stem cell research. That included... |
[
"could you orbit a planet with much higher gravity at an altitude to give you earth like gravity?"
] | [
false
] | Ok, so I'm not sure if this is even a correct premise, but if gravity decreases in intensity as distance away from its source increases. Would it be possible to have a space station orbit a planet at a set distance to simulate earth like gravity? | [
"When something is in orbit, that means that it is in freefall, and thus the experience of living inside the space station would be that of weightlessness.",
"It's true that the gravitational force drops as 1/(distance to planetary center)",
", so at a suitable altitude, yes, the gravitational force would be co... | [
"Absolutely. This is depicted wonderfully in the very science-accurate movie 2001."
] | [
"Off topic, but could a donut-shaped space station rotate at a rate such that the centrifugal force would pull you outward so as to simulate gravity?"
] |
[
"Atomic Theory"
] | [
false
] | This is a rather simple question compared to many on here. I am in a high school science class. We briefly touched on chemistry but most of the course is focused elsewhere. We were taught the Bohr Model of the atom. It was explained that the Bohr model is not a perfect way to represent the atom but it works fairly well... | [
"Here's what the various electron orbitals actually look like",
". As you can see, every orbital is described by a set of ",
"three numbers: l, m, and n.",
" The shape of the orbital comes about from solving the wavefunction for those parameters. They take on all those different kind of shapes because elec... | [
"It will be difficult to describe the exact details, but here are some important basics:",
"The Bohr model of the atom describes electrons as discrete particles that revolve around the nucleus in different orbits.",
"What current atomic theory states is that electrons are not discrete particles you can see orbi... | [
"The next level up is sometimes called the orbital model. It assumes that the attraction between the electron and the nucleus is the same as between two bulk charges particles.",
"It gives the probabilities of finding an electron in various states, and you can calculate the difference in energies of these days, w... |
[
"How did we get a picture of the milky way (if we did)?"
] | [
false
] | I feel like I should know this, but I don't. If we are inside the milky way and haven't sent and telescopes outside of it, how did we get a picture of it? I understand that we can find out how it should look like and our location on it. Do we actually have a picture of it or is it some sort of interpretation? Or is... | [
"Past",
" - ",
"/r/asksci",
" - ",
"threads",
" - on this precise question, fyi."
] | [
"We don't have a picture of it. It's all extrapolation based on the limited amount we can actually see, and what we observe of other galaxies. There's even debate about whether it's a spiral galaxy or a barred spiral galaxy. The ",
"Wiki article",
" contains several sources for recent studies which show that we... | [
"Well we have one where you see it from the side, just as you would see it if you looked up at night where there isn't a city nearby. The ones from the front are either other galaxies or CG."
] |
[
"How do scientists across the world accurately repeat experiments that use very fine weight measurements when the force of gravity isn't consistent across Earth?"
] | [
false
] | null | [
"For the majority of experiments, the variations of the Gravitational Field are small enough that any affect on the results are minimal, and quite often not relevant.",
"If the experiment relies on a more accurate measurement of the force of gravity then any weights are re-weighed extensively and for very importa... | [
"The one that instantly comes to mind is Millikan's Oil Drop experiment. Trying to repeat those results and achieving a suitably accurate result would require measurement of the local gravitational field strength."
] | [
"A common approach is to use torsional balances, which test the attraction/repulsion between two or more objects in a plane perpendicular to the Earth's gravity. This is how Cavendish measured Newton's gravitational constant, and how micro gravity research is still often pursued."
] |
[
"Why are stirling engines not used instead of passive heat exchangers?"
] | [
false
] | A stirling engine is likely the simplest of all engines. It runs by simply vibrating a piston from a hot side to a cold side. In doing so, it helps cool the hot side (the heat has to go somewhere). The piston is usually connected to a rotary output shaft. That rotor could either generate electricity or spin a fan ai... | [
"Are you considering cost and reliability?"
] | [
"Well, a heat sink is a hunk of metal. Hard to get more reliable than that."
] | [
"can someone elaborate on this? whats so special about sterling engines that makes them expensive and unreliable?"
] |
[
"Is it possible to know the charge of a black hole?"
] | [
false
] | With the event horizon "hiding" all the information about the singularity inside, how is it possible that we can know the charge of a black hole? The charge information is conveyed via the electromagnetic field, but as I understand it no light can escape from the event horizon? | [
"The charge is something you can define and measure outside. It doesn't matter what is \"inside\". As the black hole forms the field is already there, and infalling charges can change the charge - and all you need to describe this is the region outside."
] | [
"It doesn't have to propagate past the event horizon. The charge was there when the mass collapsed, or it was outside later and fell in. Nothing that happened beyond the event horizon matters for the description of a black hole."
] | [
"I might have a misunderstanding of electromagnetics then, how does the electric field propagate through space if it can't propagate past the event horizon? Does the electric field just stay static after the black hole forms, and the field from infalling matter as well? "
] |
[
"Evolution: how can new species arise?"
] | [
false
] | I work in the field of theoretical computer science; I study and love to think about complex systems. In my opinion populations and the theory of evolution fall right into this field and are the most interesting application of the theory of complex systems. However, there is just one thing I can't wrap my head around: ... | [
"You're on the right track but let's make a model to examine a key point - a species will generally be able to mate with it's parent's generation, it's grandparent's generation, going back several generations. There will never be a scenario where its like \"Oh my offspring is genetically isolated from me, hope some... | [
"First of all, this is a very good and interesting question. The subject is not, at least in my opinion, ignored nor avoided in the field but of course these type of questions do not receive as much grants and attention as do research focused on cancer and such which might be why it may seem as an ignored set of qu... | [
"Yes for sexual reproduction it would always be somewhat gradual - keep in mind different organisms have vastly different reproductive rates so \"gradual\" can still seem pretty quick to us. ",
"Species ",
" probabilistic in that you're categorizing something based on a man-made label. In truth, all organisms a... |
[
"AskScience AMA Series: We're Experts Studying COVID-19 In Deer and Other Wildlife. AUA!"
] | [
false
] | In the past two years, dozens of animal species have been found to be infected with the SARS-CoV-2 virus. Of these, only two types of animals were found to be infected in the wild: mink and white-tailed deer. These findings have serious implications for managing (and ultimately ending) the COVID-19 pandemic. Join us to... | [
"You mentioned “ending” Covid-19. Do you really think it’s possible to bring the pandemic to an end? How?"
] | [
"All pandemics technically end, even the Great Influenza (Spanish Flu) of 1918 that killed 20-50 million people. That flu virus wasn't destroyed, it continued to circulate and cause annual winter flu epidemics that killed smaller numbers of people. But technically the pandemic ended by ~1920 when it stopped causing... | [
"Is it a threat to the animal populations or only a concern as a reservoir for new infections of humans?"
] |
[
"When the topic of our existence comes up in conversation, I always say that humans exist only for about 200.000 years. How is this determined? What drew the line between humans and whatever it was called before that?"
] | [
false
] | Stupid question, but I really never had any idea how to explain it when someone asked. | [
"Are you asking what precipitated the evolution of H. sapiens? The big picture answer is a combination of sexual, natural and social selective pressures. I can go over these in a bit but I have to get to a meeting. Moreover, many behavioural and physical trends for traits that we see in the Homo genus continued to ... | [
"It's not a stupid question at all! The issue of when \"we\" as a species began is one that is subject to debate and interpretation even in the anthropological community. ",
"The 200 000 years ago date comes from ",
"this",
" site called Omo Kibish in Ethiopia where an \"anatomically modern\" cranium was foun... | [
"But the question is not about that.\nDuring what transition in history did a species evolve to something we call homo sapiens?"
] |
[
"Are there animals which are allergic to humans?"
] | [
false
] | null | [
"I'm not an expert in veterinary medicine. However, the study below cites research indicating that some dogs can indeed show an allergic response to human dander (skin, hair, other cells shed from the body). (Sorry, tried to link in text but the parentheses in the url was screwing up the formatting.)",
"http://w... | [
"You can use the backslash prior to the parenthesis to escape it. So instead of JVCS2009.2(2), you'd type JVCS2009.(2\\).",
"Link"
] | [
"unless i'm misunderstanding you, people are not allergic to cat's hair, they are allergic to proteins in their saliva, urine, and dander.",
"source",
"additionally, long haired cats are less likely to trigger an allergic reaction because their long fur holds the protein causing allergen closer to their skin ra... |
[
"If mass increases with energy, then shouldn't subatomic particles have almost infinite mass? Then why doesn't the inertial property of the particle increase and its motion stopped?"
] | [
false
] | null | [
"Mass does not increase with energy. The concept of \"relativistic mass\" has largely been discarded because in order to get the math to work, you have to define relativistic mass so narrowly that it does not really act like a mass anymore, and leads to confusion as evidenced by your question. An object that that t... | [
"Yes, there is a concept called relativistic mass, in which the mass of an object increases with its velocity. Quantitatively, you'd have mR = gamma * m0, where m0 is the rest mass of the particle, and gamma is the Lorentz factor. In the case of subatomic particles at accelerator energies, they would have very high... | [
"The other answers here are correct—but I want to add that subatomic particles don't necessarily have much energy at all. For instance, your run-of-the-mill electron has very little energy beyond its mass-energy. Subatomic particles that we shoot through particle accelerators ",
" have a lot of energy, and their ... |
[
"Does the sun rotate?"
] | [
false
] | If so, how long does a "solar day" (i.e. one solar rotation) last? | [
"Yes. It doesn't rotate rigidly, it rotates in about 25 days at the equator and 35 at the poles.",
"https://upload.wikimedia.org/wikipedia/commons/1/11/Sun_turn.gif"
] | [
"Short, sweet, to the point.",
"If you want to watch it rotate, you can track sunspots as they move across the face of the sun over the course of a couple weeks. You can project the sun onto a sheet of paper with some binoculars, or use a pinhole camera, or any of the tricks that get passed around every time ther... | [
"The sun rotates about its axis with a period of about 25 Earth days (at its equator).",
"http://en.wikipedia.org/wiki/Solar_rotation"
] |
[
"Difference between a black hole and infinite potential (e.g. coulombic) when considering Hawking radiation"
] | [
false
] | Hi. Material scientist here so I'm not big on cosmology. As I understand, hawking radiation can occur whenever we have an event boundary - for exaple sound waves moving through a fluid which is flowing faster than the speed of sound is the classic example. Can someone tell me the difference between this and, say, some ... | [
"I'm a cosmologist but not big on material science, so there you go :) My impression is that for any (finite) Coulombic potential, there are charges which can escape, and an infinite potential isn't really physical. A black hole (or a black hole analogue, like they make in condensed matter systems that trap sound w... | [
"If I have some sort of region which has infinite coulombic potential (of finite range)",
"I have no idea how you would make such a thing, or how it would make any sense physically.",
"Remember, black holes ",
" have infinite gravitational potential anywhere except (classically) the singularity at the very ce... | [
"The singularity in the Coulomb potential isn't very physical ",
" I don't think there's any problem with it quantum-mechanically though, since it doesn't lead to any unphysical results for any observables. Unless you consider a cusp in the wave-function to be unphysical. "
] |
[
"Are there objects in our eyes that our brains block out?"
] | [
false
] | I can see floaters when I look at a bright light, but there must be a whole mess of stuff in there! | [
"Do you mean foreign objects, like dust? If so, I think our eyes do a pretty good job of removing stuff like that. Here's what wikipedia has to say about floaters: ",
"http://en.wikipedia.org/wiki/Floater",
"As for our optic nerve, it does indeed give us a \"blind spot\" in our field of vision. Want to know ... | [
"Floaters and blood vessels exist in our eyes."
] | [
"optic nerve"
] |
[
"Can light, be it wave or particle, ever be motionless? or do they have to have some speed at all times?"
] | [
false
] | null | [
"A full and precise explanation would require more math than is appropriate here. However, the short answer is no. A photon (which is massless) cannot stand still; it must always travel at c as a consequence of relativity. In fact, the existence of a massless particle at all is a consequence of relativity, so it... | [
"Thing is, a \"photon has no rest mass\" or mass of any kind, when mass is 0, acceleration is infinite for any sort of force that you can apply to it (also read the * if you haven't by now). So, if you have a particle of mass zero, the second you flick it, it zooms off at infinite (or in a limited frame of referenc... | [
"It should also be noted that speed of light is a really important feature of this universe, it's something derived directly from the properties of space-time. It's not just some arbitrary stick in the mud somewhere."
] |
[
"Why is there supersonic wind on Neptune and how do we know about it?"
] | [
false
] | null | [
"They measured the movement of observed clouds from a voyager satellite. Why is being debated? Strong planetary rotation, internal heat fluxes, active thermodynamics associated with the hydrologic cycle, and a shallow atmosphere are all important factors."
] | [
"So I can only suppose they're talking about the speeds of the wind relative to each other.",
"Nope, we measure wind speeds on giant planets relative to the rotation rate of the magnetic field. That's also a good estimate of how quickly most of the interior is rotating, too, since that's where the magnetic field ... | [
"Correct, all the magnetic field rotation measurements came from Voyager 2's flyby. Neptune's magnetic field is ",
"highly inclined",
" relative to its rotation axis, producing a very clear signal - unlike Saturn, where the magnetic field is perfectly aligned with the rotation rate and we have to come up with o... |
[
"How are my eyes changing to a completely different colour as I grow older?"
] | [
false
] | I was born with dark brown, almost black eyes. When I was about 16 I started to notice small flecks of green at the bottom of my eyes. Now at almost 25 my eyes are nearly completely green. My father, who now has grey eyes, told me he had the same thing happen to him as he grew older. He said that he went from dark brow... | [
"This image",
" has best explanation that I've found ",
"I don't work on the anatomical or genetic side of vision, but my ",
" rudimentary understanding is that the amount of melanin can change with age. ",
"Your father probably has a differently structured stroma, so his eyes became gray. Maybe an anatomis... | [
"Thanks for the link. It's nice to know a little about whats going on :)"
] | [
"Nope no meds. Though I may ask my parental units if I took anything as a child that would have that effect."
] |
[
"If we were to build a bridge perfectly straight from the north pole, how long could we walk on for?"
] | [
false
] | Assuming we could build a bridge, or walkway similar to the one in this , (infinite flight aside), how might we expect to experience walking the length of it? How would we be affected? | [
"OP asked about the ",
" of walking the length of the bridge, so here goes:",
", you would be on a causeway 40 feet tall, high enough that a fall would cause serious injury. The slope would be so mild that you wouldn't notice it.",
", you would be as high as the ",
"Burj Khalifa",
", the tallest structure... | [
"You fall straight down, not sideways as in the drawing. Down in our case is toward the center of the earth, so you'd fall at at roughly 45 degree angle to your bridge (if you were able to build it out that far).",
"This also gives you some insight about how gravity pulls on your bridge. At the pole, you'd feel... | [
"You would experience such a walk as going up a ramp that became steeper and steeper. Draw a line between any point on the ramp and the center of the earth and you can see how steep the ramp would seem at that point."
] |
[
"What exactly does a sex change entail?"
] | [
false
] | I am just curious as to exactly what it means to have a sex change operation. Do converted genitals function as they would normally? Seeing as how you are still genetically XX or XY (for the most part), to what extent could someone actually change genders? | [
"There is no such thing as \"a sex change\" surgery. There are many different genital surgeries, and many trans people do not get any at all.",
"Trans women, a.k.a male-to-female transsexuals: The most common genital surgery is orchiectomy. (castration) This will greatly reduce testosterone levels in the body and... | [
"I've had several friends who have undergone this, I'll share my gained knowledge...",
"They make you live as the opposite sex for at minimum one year before allowing any operation. During this time you dress, act, speak, and use the appropriate changing/bathroom areas as your desired sex. You take the appropri... | [
"The penis gets removed, the head is whittled down into a clitoris, and the balls are removed. They take the leftover flappy bits and try to make them look like a vagina, but t doesn't. Depth of the new \"vagina\" averages around 5 inches, and lubrication is always needed, as fake vaginas cannot self-lubricate."
] |
[
"If the planets in our solar system are formed from basically the same gas and mineral debris compressed over time, why are they so different from each other?"
] | [
false
] | My basic understanding is that gas, space rocks, asteroids, planetoids, etc. attracted to and trapped in the orbit of the sun eventually grew larger and larger until their own gravitational pull compressed themselves into planets. If this is close to correct, why are the planets so vastly different? The best analogy fo... | [
"Because the mixing of the material wasn't totally random-- there was a pretty significant influence on how it was sorted. Also, the planets, particularly the outer ones, did not necessarily form in their current orbits. Most of the outer ones likely migrated outward.",
"Let's assume, for the sake of argument, th... | [
"Your planetary formation explanation doesn't mention the \"snow line\", which is really key to the resulting difference between inner rocky planets and outer gas planets. Somewhere around 3 AU and beyond, it's cold enough that water can exist as ice instead of just gaseous water vapor (note that you can't make liq... | [
"You're right, I was talking about the atmospheric composition when I should have been talking about the overall composition."
] |
[
"How do we know the age of the sun?"
] | [
false
] | My mom asked me this question and while I think I have a decent understanding of astronomy and astrophysics, I don't know the answer. Googling was unhelpful (it told me the age, and vague hand-waving about how stars are formed, but not a real answer). I guess that we just know what stage of the star's lifecycle the sun... | [
"We can measure the sun's mass, energy output, and chemical composition.",
"On earth, we can measure the mass of various atomic nuclei, the energy output of various fusion processes, and the age of the oldest rocks.",
"Put this all together, and we can start making some reasonable guesses and set upper and lowe... | [
"Recent article",
" which goes a bit deeper, with lots of relevant references."
] | [
"Wikipedia is your friend. From the ",
"article",
"Solar formation is dated in two ways: the Sun's current main sequence age, determined using computer models of stellar evolution and nucleocosmochronology, is thought to be about 4.57 billion years.[86] This is in close accord with the radiometric date of the ... |
[
"Why is it that carbonized wood (charcoal) is used for it's heat instead of plain wood? Shouldn't it contain less energy since it was \"burned\" off?"
] | [
false
] | null | [
"The energy used to get rid of all the water and excess hydrocarbons from wood is quite large. Charcoal isn't actually ",
" already, in that it is done in a low oxygen environment (incomplete combustion).",
"What you're left with is far more efficient because burning off all of those waters and hydrocarbons mea... | [
"To make charcoal, you take a piece of wood and you break up many of the chemical bonds. This releases energy, true, but it also puts the remaining energy into a much more easy-to-release form.",
"It's analogous to the reason you don't want to put one gigantic salt crystal in your soup. You're rather have it brok... | [
"Interesting! Thanks!"
] |
[
"Is there such a thing as an \"anti-scent\"? That is a scent that is close to the opposite of a scent that can somehow cause the effect of cancelling out, or lowering the original scent?"
] | [
false
] | also: is there a link to a list of scents that are the natural offsetting "anti-scents" to the original? Thanks | [
"There are odor antagonists, which can keep you from smelling a certain class of molecules. However, the antagonist itself is usually odorless, or smells pretty similar to the odor which it is \"cancelling out\".",
"http://chemse.oxfordjournals.org/content/34/7/625.short"
] | [
"Are you interested in the human nose, or just volatile chemicals in general? There are things that can 'mask' an odor by out-competing and binding with a series of receptors on the nose, but they don't 'get rid' of the chemical in the air - they change our perception of it."
] | [
"I'd like to figure out the best way to mask the smell of linseed oil "
] |
[
"How do you predict the outcome of a covalent bond?"
] | [
false
] | Sorry if this is a bad question. How is it that you can get SO2, SO3 and SO4? Why don't they just share the atoms among just SO? And how come the charge doesn't change among them? | [
"Charge does change among them.",
"Sulfate (SO4) carries a -2 formal charge",
"Sulfur trioxide (SO3) carries a formal charge of 0.",
"Sulfite (SO3 as well) carries a -2 charge",
"Sulfur dioxide (SO2) carries no charge.",
"We get the different sulfur compounds due to the reagents involved in production. "... | [
"Why do SO3 and SO4 have the same charge? And can you give an example of reagents that would affect the compound? Why wouldn't the compound want to end up as SO3 or SO2 which both have a charge of 0? And how do they have the same charge if one possesses an additional atom?"
] | [
"I am going into grade 12 chemistry very soon and am recalling how I never learned about this in grade 11 chemistry. When I would ask my teacher she would say \"It's not on the exam, so don't worry about it!\"."
] |
[
"Does wearing sunblock every day leave you naturally unprotected and dependent on the sun screen?"
] | [
false
] | null | [
"Unfortunately, you seem know just ",
"enough about this to be dangerous",
".",
"Without question being paler increases the damage the sun does to you. However, the difference is miniscule compared to the protection provided by the sun block in the first place, which is UV opaque, unlike your skin.",
"So, n... | [
"However, the difference is miniscule compared to the protection provided by the sun block in the first place, which is UV opaque, unlike your skin.",
"Indeed. Also, it should be pointed out that tanning, ie. the production and redistribution of melanin by your skin, only happens in response to UV damage. So you'... | [
"You don't get very much vitamin D from being in the sun, roughly 10-30 minutes is really all you need after that the returns are greatly diminished or aren't even there, as at a point the uv rays destroy the excess vitamin d, and the risk of skin damage [cancer] outweighs the benefit. Also you can get Vitamin D fr... |
[
"Novel Mathematical Proofs: Are they discovered or invented?"
] | [
false
] | null | [
"The question of whether mathematics is discovered or invented is a deep philosophical issue about which is there is not consensus (realists and Platonists take the former view, intutionists and constructivists the latter).",
"To get a sense the range of thinking on this matter see",
"http://en.wikipedia.org/wi... | [
"This is really more of a philosophy question. I suggest you take it to ",
"/r/askphilosophy",
" or maybe ",
"/r/philosophy",
"."
] | [
"As most proofs of a certain thing are equavilent end merely expressed differently, it is hard to say something new is invented when somebody figures out the relationship between various things. For example, the golden ratio was always there before the discovery, as well as Maxwell's equations. The matematical proo... |
[
"\"There's a chemical reaction. It was a powerful singular thrust to the neck.\" -Sleepy Hollow"
] | [
false
] | null | [
"The film bears very little similarity to the original short story, IIRC the whole forensics element is entirely new. It was most likely artistic licence on the side of the filmmakers. "
] | [
"Thanks for this, I've never had the pleasure of reading the original tale. I've added this to the OP."
] | [
"Where's the link?"
] |
[
"What makes a deep-sea fish able to live in that immeasurably high pressure, where a submarine would be tore apart?"
] | [
false
] | I've been searching for an answer on Wikipedia, but the only thing that I found is that they adapt. I'm really curious about how they adapt in organs and stuff, and what differentiates them from a normal fish. | [
"They consist mainly of water, which is almost incompressible and is also the medium of the environment of these fish. So they do not experience any pressure gradient at all.\nA submarine, on the other hand, is filled with air which can easily be compressed by a factor of 100 at these depths. So you have to build a... | [
"Something similar is called a ",
". This has a small air-filled crew cabin, which needs to withstand the incredible pressures, supported by a float filled with petrol. Petrol is less dense than water so provides buoyancy, and the float is not crushed because it's liquid both inside and out."
] | [
"So let’s just make a submarine of water - right?"
] |
[
"How come that rail tracks can be weld together and they don't bend when the temperature changes?"
] | [
false
] | I saw a documentary (not sure what was its name) about building a railroad in Spain. It was a high-speed rail (Madrid to Barcelona I think). They were using very long rails (250m I think) and they alwasy welded them together. Sidenote: If we have a metal rod, it expands when temperature changes, right? It expands to al... | [
"http://en.wikipedia.org/wiki/Breather_switch"
] | [
"The track structure itself resists the stresses from temperature change. The stress is transferred to from the rail to the tie through anchors or elastic fasteners, then from the tie to the ballast that it is embedded in, and to the subgrade.",
"When laying the rail, it is heated to the desired Neutral Temperatu... | [
"Interesting stuff. The regional rail network in Victoria, Australia (VLine) runs a fast rail system where trains reach speeds of up to 160 km/h (100 m/h). These services started running about 5 years ago on newly built/upgraded sections of track.",
"Since launch they have introduced ",
"hot weather speed restr... |
[
"Why does stuff in the Universe like to rotate?"
] | [
false
] | Everything out there spins. From galaxies all the way down to quarks. I read "the solar system condensed and started to spin..." Why does everything like to spin? And for a bonus question; does stuff always spin the same direction? I mean, except for cases where a planet gets knocked sideways, etc. | [
"Imagine you have a massive cloud of dust. The odds of the total angular momentum of this cloud being exactly zero is negligibly small. This means the cloud is rotating very very slowly with a defined direction. Now consider what gravity does to the cloud. It will cause the cloud to collapse in on itself. As t... | [
"That explains the macro scale, but what about particles? Obviously they're different phenomena, but why does an electron or quark ",
" have a spin?"
] | [
"I'm not sure if I can get to the ",
" of this question, but I can maybe offer some insight. Electron spin is kind of a misnomer. It is not the electron actually spinning. It is simply an amount of angular momentum that the electron must have (and happens to be quantized). Why must the electron have this spin... |
[
"Does a person suffering from amnesia retain the personality traits formed from/during the experiences they can no longer remember?"
] | [
false
] | null | [
"Wow, no comments still...",
"It really depends on what types of traits you mean. H.M. (Henry Molaison) is the best studied case of amnesia, though he had both retrograde amnesia (memory loss), and complete anterograde amnesia (cannot make new memories).",
"After a surgery, he lost certain memories of his past... | [
"Just read up on him and this last bit I read was very interesting.",
"\"Near the end of his life, Molaison regularly filled in crossword puzzles. He was able to fill in answers to clues that referred to pre-1953 knowledge. For post-1953 information he was able to modify old memories with new information. For ins... | [
"I had a small stroke several years ago and I've noticed this phenomenon with my own memory. Things I learned before the stroke came back fairly easily but trying to learn a new skill is much more difficult. Once I could concentrate reliably again, I picked up the crafts I'd abandoned in the order in which I'd prev... |
[
"What is the probability of shuffling a random deck of cards into new deck order?"
] | [
false
] | Also, how long would it take for this to occur? | [
"Without jokers, the probability is 1 in 52! or 1 in about 8.07 x 10",
" . And, if I mathed correctly, it would take about 5.59 x 10",
" shuffles for that to occur on average."
] | [
"For those not familiar with the notation, that's 52 factorial he's talking about (he's not just super pumped to tell you the odds are 1 in 52)."
] | [
"Persi Diaconis -- professional mathematician and magician and MacArthur recipient -- and collaborators have provided a rigorous mathematical analysis of shuffling. You can read about the various results ",
"here",
", which includes reference to the ",
"1992 paper (PDF)",
" with Dave Bayer proving the 7 sh... |
[
"Why do prion diseases have 100% mortality rate?"
] | [
false
] | null | [
"Prions are simply misshapen proteins that have a rather unique ability to change their counterpart normal proteins around them into more misshapen variants. Because they were normal proteins there is no immune response against them so they are allowed to just sit there eventually turning your brain into Swiss chee... | [
"Nope, it is extremely rare though."
] | [
"Nope, it is extremely rare though."
] |
[
"What would happen if you were shot with a single, non-radioactive atom?"
] | [
false
] | Let's say there's a gun that fires atoms at bullet speed, what kind of effect, if any, would the atom have on the body? | [
"Virtually nothing, your body is bombarded by atoms and particles traveling far faster than that on a daily basis and very little damage is ever done. This is a much bigger concern in outer space where astronauts don't have Earth's atmosphere and magnetic field to shield them from cosmic rays, which can eventually ... | [
"The Ivory Soap of velocities.",
"I think OP might have been wondering whether the atom would interact with the body, or just pass through it. "
] | [
"Indeed, some of them as fast as ",
"99.99999999999999999999951% the speed of light"
] |
[
"Does exercising help my brain function?"
] | [
false
] | null | [
"Yes. I read a book called Brain Rules which talked about how, compared to those in a sedentary life style, those who have 30 minutes of aerobic exercise 3x a week had significant increases in reaction time, executive function, and mathematical thinking. I think mathematical thinking was double in the aerobic group... | [
"These effects exist for all age groups, and effects are limited to executive function. Minimal impacts are found, for example, on verbal fluency. But you nailed it - 3x/week, 30 minutes, high but sustainable heart rate throughout. ",
"As to WHY these effects exist, the answer requires some speculation. A connect... | [
"I'm confused about what executive function is."
] |
[
"If the human body were to be struck by a very small object (say a needle or something smaller) shot out of a rail gun and traveling at a huge velocity, would this object transfer all of its energy and rip the body apart or would it just blast straight through and leave a pin sized hole?"
] | [
false
] | How does energy transfer based on the size of the object? If it were to shoot clean through and not hit any major arteries or organs, could one survive this impact? | [
"If the needle is very small (in cross section) but built to deform on contact then it could distribute more energy. This problem is an actual science - weapons designers want to either maim or kill (depending on the application) as many enemy as possible for a minimum \"investment\" of mass/propellant. Tanks can c... | [
"I don't know. I think they fixed it such that the \"needle\" wouldn't skewer anyone again (I think it passed through an office and chair, but it was late at night.) They had already anticipated the vessel rupturing (it was in a bunker in the basement) but had expected shrapnel/disintegration rather than a single r... | [
"I don't think they were being crazy reckless. The pressure vessel was about the size of a coke can. When under pressure it was at night (empty building) and in a big room with nobody near it - control was from far away. It's not anticipating that mode of failure that caught them out. ",
"That said, they could ha... |
[
"Does the Higgs Boson give mass to itself?"
] | [
false
] | Does the Higgs boson interact with the Higgs field so give itself mass? Would this be similar to the behavior of gluons that (as far as I understand it) add to the strong color charges nearby themselves? | [
"higgs boson : higgs field",
"photon : electromagnetic field",
"electron : electron field",
"(and so forth)"
] | [
"we'll see is the best answer I can say. It depends on if/what the Higgs boson ends up looking like."
] | [
"The Higgs boson is not about gravity at all. Or at least only very indirectly so. We know particles have mass. We would like to know ",
" they have mass. The leading idea is that they couple to a Higgs field, and that ineraction gives rise to mass behaviour. In order to prove it's right, you have to show that th... |
[
"Space Suit Manufacturing"
] | [
false
] | What keeps us from making space suits that are more compact and mobile? edit: I do already know some of the general reasons. So, I am really looking for more in depth explanations on why we are not able to solve the problem of suit pressure decreasing mobility. | [
"Current \"production\" space suits are flexible human-shaped air bladders. They work by holding in air, providing a constant-pressure environment for the human to exist. They also have to have several layers: protection for the bladder from dust, micrometeorites, and wear-and-tear; insulation to prevent excessiv... | [
"Atmospheric pressure on mars is only about 0.08 PSI. The pressure difference between inside the suit and outside the suit on mars would be almost exactly the same as being in space."
] | [
"This guy",
" developed a suit for use on mars. The ",
"mars atmosphere",
" is about the same pressure as 115,000 ft above Earth, about the height of the ",
"Red Bull Jump",
". ",
"Here is the suit",
" that Felix wore."
] |
[
"Can anyone please explain what appears to be a boundary layer over the wing from my flight last night?"
] | [
false
] | I was a passenger last night in an A320 at 34,000 ft when I looked out at the wing only to see a weird, light-bending boundary layer (I think). I had to blink a few times to make sure I wasn't just seeing things. This thin strand (sometimes three closely-spaced strands) bounced back and forth with turbulence. I leaned ... | [
"You're seeing a local shock wave - even though the plane is not traveling faster than the speed of sound, at certain spots over the top of the wing, the local airspeed is faster than the speed of sound. A shock boundary is a local 'jump' or discontinuity in pressure and density, which refracts the light differentl... | [
"Air flowing over the wing decreases in pressure. As it decreases in pressure, water vapor condenses out of the air, forming a cloud like the one you saw. ",
"Here",
"'s a more extreme example."
] | [
"That is caused by the shock, when the fluid is locally accelerated to Mach > 1. As the pressure decreases when the fluid is accelerated, the air-density also decreases and influences the refraction index..."
] |
[
"What kingdom or domain of life are viruses in, and what differentiates them specifically from other single-cell organisms like bacteria?"
] | [
false
] | I was doing some reading for fun on this and I can't find them anywhere in the Taxonomy wikipedia( page | [
"The list your looking at details cellular life, the 3 domains don't include Viruses, on account of them not being cellular life. ",
"I belive there are people that want to add 4th domain to account for \"non-cellular\" life such as virus. ",
"https://en.m.wikipedia.org/wiki/Virus_classification",
"the bigge... | [
"So does fire, by many of the common definitions of life. Coming up with a ",
"scientific definition of life",
" has been a bit of struggle and ongoing debate. Most textbooks these days will give you a list of characteristics that living things have, such as reproduction and metabolism, a list that neither viru... | [
"Looks like this one is mostly handled, but for a little bit of added clarification about viruses not being cellular life- What a cell is has a distinct definition in Biology. Cells have either a membrane or wall, and contain a nucleus and a number of organelles. Viruses are simply DNA/RNA wrapped in a protein enve... |
[
"What is the difference between a good and an outstanding music instrument?"
] | [
false
] | For example, can we say that a superb violin produces a different spectrum than an ordinary one? | [
"As a French Horn player, I can try to explain this as it is for brass instruments.",
"It is predominantly down to a few things: the quality of the metal it is made from, the valves, the connections between the pipes and the flare.",
"Firstly, the metal is made from. If you took a lump of doorhandle, melted it ... | [
"For science, set up some really sensitive microphones around a room, and have a simple machine that does the \"Sound making action.\" If you switch out the instruments, you'll be able to hear the differences and even observe the wave forms using some cool software. The difference between a shitty instrument and ... | [
"Record a note then load it into MATLAB. Use the FFT function to examine the harmonics. Then, overlay the harmonics for both crappy and good instruments. That'd be cool."
] |
[
"Could you stop a tornado with a large explosion?"
] | [
false
] | null | [
"In theory you could, but it's a terrible idea for just about every reason imagineable",
"."
] | [
"Here's the answer for a scaled up version: ",
"http://www.aoml.noaa.gov/hrd/tcfaq/C5c.html"
] | [
"How about some fluids-informed speculation? It's possible to stop a vertical vortex either by injecting dense material into the updraft, or also by disrupting the circular flow in the \"wall\" near the core, which eliminates the centrifugal action and radial pressure distribution in a small region, essentially \... |
[
"Why do humans have many specialized cells, rather than one cell that can perform many functions?"
] | [
false
] | null | [
"By specializing the cells they can perform better- for example the thin alveoli cells can absorb oxygen and co2 faster than the thick skin cells of your foot which resist trauma from collision.",
"This improved performance grants organisms a major advantage."
] | [
"That's the answer I was looking for, thanks!"
] | [
"It's part of our evolutionary history.\nIn the beginning there were single cellular organisms. Then some formed colonies which could as a group achieve something that each individual cell couldn't. Then some of these colonies organised in a way that assigned different functions to these identical members. Thus mul... |
[
"Origins of Life"
] | [
false
] | How could life on earth have originated without oxygen being present in the atmosphere? | [
"Most all early life was anaerobes, which do not need oxygen and instead can release it as a byproduct. In fact oxygen would have been quite toxic to early life on Earth. There are still many anaerobes in existance today, in fact inside your gut right now are billions of them"
] | [
"Methane contains no oxygen. The oxygen comes from nitrite who reacts with methane."
] | [
"Thanks for the correction. I was in a rush unfortunately."
] |
[
"Since your liver regenerates, can you remove and freeze a chunk of your healthy liver at a young age, and then use it as a backup to regrow your liver later in life after it's been damaged?"
] | [
false
] | [deleted] | [
"Theoretically, but the real problem is that it’s very difficult to avoid damaging living tissues in the freezing process to the point where it’s unusable. Unless you have access to decent quantities of liquid nitrogen and a suitable storage environment, such as a large industrial dewar, ice crystals will inevitabl... | [
"While pate is chilling, take 500g fava beans (fresh, shelled) and boil for 5 min. Immediately remove and place in ice water bath to cool. Once cooled, sauté beans in equal parts butter and olive oil for 7 minutes, until tender. Salt and pepper to taste. Best served with a nice Chianti."
] | [
"No, but they have done somewhat related things with frozen ovaries. It’s still experimental and early days, but they’ve removed and frozen sections of ovaries, then reimplanted them later and they’ve worked. I think they’ve tried sewing them to an existing ovary, but also they’ve implanted them in the arm. They’re... |
[
"Boundary Conditions of EM field Around a Solenoid in Cylindrial Coordinates"
] | [
false
] | My first askscience question! How exciting! I am having trouble with some EM field simulations and I think my problem is my boundary condition assumption. I am simulating a solenoid with several cylindrical layers of dielectric material inside and outside of it. I am trying to get some numerical solutions to this thing... | [
"Do you have access to Jackson's E&M textbook? I think he discusses similar problems in all their gory detail."
] | [
"Yep. If you don't have it, it shouldn't be hard to find in a library or used (or...in pdf form...somewhere on the internet...).",
"It's the standard physics graduate student E&M textbook...so there's lots of them around."
] | [
"this?"
] |
[
"Why are semiconductors used in photovoltaic cells instead of conductors?"
] | [
false
] | Actually, not only in PV cells, but in almost all electronical devices. How come? | [
"Going a little further - electrons can flow through conductors easily, but can only flow through semiconductors under certain circumstances. These circumstances (voltage, electric field, etc.) can be indirectly adjusted in the semiconductor to optimize it for particular applications - by altering the structure of... | [
"There are two energy bands you need to worry about, the valence band and, at a higher energy, the conduction band.",
"See ",
"here",
". Semi-conductors are useful because the band gap is non-zero (the valence and conduction bands do not overlap) but small enough for electrons to move from one to the other wh... | [
"Thank you!"
] |
[
"Are Rubbing Alcohol & Hydrogen Peroxide actually bad for cuts? [MIC]"
] | [
false
] | 1) Doesn't rubbing alcohol make the blood thinner which actually causes you to bleed out more? Is rubbing alcohol actually a good disinfectant at all? Is it bad for cuts? 2) Wouldn't Hydrogen Peroxide be bad for cuts as it actually eats away at good and bad tissue? In the time that your tissue recovers from Hydrogen Pe... | [
"Normal saline is really only good for irrigation, it isn't considered antibacterial."
] | [
"Most of the dressings I've done consisted of clean bandages and normal saline, no antibiotic component. "
] | [
"Normal saline works just fine for most wounds and it doesn't hurt or irritate it. "
] |
[
"If our moon causes our tides, and considering the size, wouldn't moons around a planet the size of Jupiter have tides that would flood entire continents?"
] | [
false
] | Pretty self explanatory... I know there is no moons like earth with liquid water on the surface around Jupiter, but theoretically the tides would be enormous, right? | [
"(not my field of expertise) The moons of Jupiter have huge tidal forces. For instance take Io, it's the closest large satelite of Jupiter and it's tidal forces are so extreme that they heat the core of the moon, causing volcanos with plumes hundreds of kilometers high!",
"http://en.wikipedia.org/wiki/Io_(moon)#T... | [
"Fuck. That is pretty much the definition of 'awesome'."
] | [
"I'd say ",
"carbon dioxide at 460",
" C and 90 atmospheres of pressure",
" is pretty hellish."
] |
[
"Could we recreate the pyramids?"
] | [
false
] | null | [
"Hello,",
"Open-ended questions are more appropriate for ",
"/r/AskScienceDiscussion",
".",
"Cheers."
] | [
"Thank you for your reply but, sorry, it is physically impossible to find good answers and scientific discussion in ",
"r/AskScienceDiscussion"
] | [
"Well your question has been removed from ",
"/r/AskScience",
", so it needs to be posted elsewhere. You can choose to post it to AskScienceDiscussion or not.",
"Cheers."
] |
[
"If a helicopter were to ascend in a perpendicular line, hover, and then descend in a perpendicular line, would it be able to eventually deviate from its original launch point when it lands, due solely to the Earth's rotation?"
] | [
false
] | That is, could a helicopter "defy" or "counter" the effects of the momentum of Earth's rotation simply by hovering, and if so, approximately how long would it have to hover for? Fuel is not a factor. Somebody posed a similar question, which I was unable to locate, on Reddit a while back and it had little to no followup... | [
"No, probably not. As the helicopter goes up, hovers, and then descends, it will always be stationary w.r.t. the surrounding air. The thing is, the air itself is ALSO rotating along with the earth. If this weren't the case, we would always have a pretty stiff breeze, because the earth would be rotating, but the ... | [
"You could do something like that, but you would need a rocket, not a helicopter.",
"The helicopter pushes against the atmosphere around it, which is also circling the earth at great speed. You'd have to break free of the atmosphere before you could use the earth's rotation to your advantage. And the cost of do... | [
"The air at the equator on a calm day is going 1000 miles per hour. \"Staying still\" would require going through that air at that speed. No helicopter can achieve such an airspeed."
] |
[
"Why feature of sound causes words or instruments to sound so different."
] | [
false
] | Why do sounds not all sound like this: I understand frequency determines pitch and amplitude determines loudness. What changes the 'timbre' of a sound eg. a clarinet vs a flute. How do we distinguish different words? What physical feature of sound waves determine the sounds of the different vowels for instance? Why do ... | [
"With instruments, they have a harmonic structure. That is, there is the bass note, lets say A which is 440, and then that value times various integers, so 880, 1320, 1760 and so on. Those integer values are called harmonics. A musical note can be defined as a sound that has harmonic structure of those integer valu... | [
"One of Vihart's awesome videos covers this ",
"here",
". Be warned, if you haven't encountered her videos before be prepared to waste the next few hours."
] | [
"She is fantastic. Thank you"
] |
[
"I don't know if this is a question of politics rather than science, but why is NASA spending so long developing the Ares V to be a HLV? Why can't they just pull the Saturn V out of retirement if they'll both cost similarly?"
] | [
false
] | null | [
"I can't speak to the first question, but ",
"this",
" essay describes several of the challenges in restarting production of the Saturn V's engines, and why a new rocket would have to be developed to use them. The answer is not simply that the plans for the Saturn V were destroyed, as is widely reported on the ... | [
"To piggyback - very little, if any of the physical production facilities exist. Machining parts like this requires machine tools that are often specific to the job. Those aren't going to be left taking up valuable floor space in a production plant."
] | [
"Wouldn't it cost more to develop a whole new rocket though? Why not just bite the bullet and rebuild it all?"
] |
[
"Is there any significant difference between cars that drive on different sides of the road? Are their blueprints just a mirror image of each other or are there some challenges to overcome for each side?"
] | [
false
] | [deleted] | [
"Don't forget about the brake booster, master cylinder, and pedal. With that comes new plumbing for the brake lines. There is also the clutch pedal and routing for that system if the vehicle is a manual. If the vehicle has a floor pedal instead of hand brake, that whole system needs to be redone and rerouted. T... | [
"Nope only the dash, steering column, windshield wipers, and headlight adjustments flipped. It's not too uncommon to find cars in the US converted to RHD. Some people buy the front half of a car known as a clip, usually imported from japan, and would swap out the parts. The steering column is the only thing that re... | [
"You are not wrong, I just want to point out some cars are made with RHD/LHD swapping in mind. For example, late model RX7. The Jspec is LHD, but to swap it only requires the RHD dashboard and a small kit of parts (including longer brake lines/accelerator cables). It's easily done. I've done it. ",
"I have a... |
[
"How does the shape of a hyperbolic cooling tower (like those in nuclear plants) help evaporate water/remove heat?"
] | [
false
] | null | [
"The hyperbolic shape itself does not help the cooling of a power plant. ",
"What makes the cooling successful is the height of the tower: by \"protecting\" the warm and moist air further up, it will maintain an updraft inside the tower.",
"The hyperbolic shape is just to have a stronger structure to deal with ... | [
"Also the Hyperboloid shape is used in construction of cooling towers because the hyperboloid is what's called a double-ruled surface, which means every point on the surface is the intersection of two lines that are also on the surface. This means hyperboloid constructions are strong and can be cheaply built using ... | [
"By moist, I mean water vapour, not water droplets. If we talk about gases, any gas molecule can approximated to have the same volume (it's true to quite a few digits of precision). 99% of air is made of Nitrogen and Oxygen, but these two elements usually binds to themselves, making a dinitrogen or dioxygen molecul... |
[
"How exactly do electromagnetic waves carry data through the air?"
] | [
false
] | I've been under the impression that radios signals are turned on and off rapidly to represent 1's and 0's. Am I correct or is data transmitted somehow else entirely? Edit: To clarify, I'm talking about all wireless technologies, such as wifi and Bluetooth. | [
"I tend to disagree that AM is turning the signal on and off. The whole carrying thing deserves a better explanation than that.",
"OP should check this video which explains it quite simply and makes a great base to understanding it better: ",
"http://www.youtube.com/watch?v=4Qgg_upU_5s"
] | [
"802.11ac",
" uses up to 256-QAM. ",
"802.11n",
" uses up to 64-QAM.",
"QAM",
" uses a combination of shifting amplitude and phase to transmit information. The AM part might be a familiar concept to many, but ",
"PSK",
" (Phase-shift Keying) might not be. To see a breakdown of just the phase shift ... | [
"Turning the signal on or off (or more precisely varying the amplitude) is called amplitude modulation (AM) and is one way to transmit data. A more common way for high data rates is frequency modulation (FM), where the frequency of the signal is shifted a fraction of a carrier frequency. E.g. in WiFi the main signa... |
[
"What differences would there be in a planet with a different water-to-land ratio from Earth?"
] | [
false
] | Everyone knows that the Earth is composed of 70% water and 30% land. Let's say that there exists somewhere a planet absolutely identical to Earth in its size, distance from its star, its geological makeup, etc, except that it is composed of 30% land and 70% water. Or say, an equal 50-50 ratio. What changes, ecological ... | [
"This is a really good question. ",
"There would be quite a lot of differences. For starters, the oceans act as something of a temperature buffer, so with more land you would see more extreme seasonal and diurnal temperature fluctuations. With more or larger land bodies you will get more extreme daytime heating,... | [
"Wouldn't a lack of water also result in fewer/weaker storms since there is less water vapor available?"
] | [
"Possibly, yes, although more land suggests there's a chance for more forests, which are excellent at putting large amounts of water vapour out."
] |
[
"Is kinetic energy/ mass relative?"
] | [
false
] | Motion is relative. Velocity makes an impression on spacetime in the same manner as mass does. Is that impression relative, depending on who's measuring it? Or is it measured relative to a stationary spacetime standard? Does this make mass relative? Tl;dr: How do I relate? | [
"Mass is invariant, kinetic energy depends on the reference frame. \"Velocity makes an impression on spacetime in the same manner as mass does.\" isn't a meaningful statement."
] | [
"Yeah, it makes more sense just to consider momentum p=γmv, where the mass is invariant, rather than demand p=mv where m changes."
] | [
"Yeah, it makes more sense just to consider momentum p=γmv, where the mass is invariant, rather than demand p=mv where m changes."
] |
[
"How does passing genes/traits to offspring work?"
] | [
false
] | [deleted] | [
"There are different kinds of traits. Mendelian traits refer to the simplest ones where its only 1 gene that affects the trait. For example lactose intolerance can be a mendelian trait because a protein is expressed and active if you arent intolerant and isnt expressed well/inactive when you are intolerant.",
"Ho... | [
"Not the original poster but is semidominant another term for incomplete dominance or are they different things? It’s just that I’ve never heard of semidominance before."
] | [
"Theyre the same thing! Just another name. Now there is a difference between those 2 synonyms and codominance. Incomplege dominance its a blending of the 2 alleles while codominance its weirder where one is dominant in one part of the tissues and the other is dominant in another. A good example is how you can get ... |
[
"Why is it, that the smaller of a particle we want to detect, the larger of a detector we must build?"
] | [
false
] | [deleted] | [
"All of these very small particles are held together by very strong forces. In order to find smaller particles, we have to bash them together at very high speeds in order to break those forces and see what things are made of. It's not the ",
" that's large, it's the particle accelerator. We use electromagnetic fo... | [
"Also, not all of the particles are small. The Higgs Boson is about as heavy as an Iodine atom, massing as much as around 125 protons and/or neutrons."
] | [
"All particles are \"epiphenomena\" (a secondary effect or byproduct that arises from but does not causally influence a process) of excitation of fields. It's the higgs field which gives fermions their mass. Not the particle. It takes a lot of energy to excite this field into a particle hence the higgs bosons high ... |
[
"Are we born with bacterias in our stomach or do they develop afterwards?"
] | [
false
] | null | [
"Until quite recently it was assumed that the interior of a developing fetal gut was sterile. However, there are now multiple lines of evidence to suggest that initial colonization of the gut by microbes occurs before birth. How the bacteria cross the placental barrier and how it is absorbed by the fetus is not... | [
"It's important to note that there's still very good evidence that significant colonization also occurs during birth, such that babies born via C-section have different gut bacteria than babies born vaginally.",
"So, a newborn's gut bacterial community is presumably a mix between what it was exposed to in the pla... | [
"The link between maternal microbiome and offspring allergies would undoubtedly be a difficult one to make, but it is entirely possible. ",
"this",
" article describes how high fat diets in macaques can alter the fetal microbiome."
] |
[
"If light travelled at the speed of sound, would we be able to see light \"echo\" ?"
] | [
false
] | If instead of travelling at 300 000 m/s (sorry for those of you who don't use the metric system) it travelled at the speed of light (+- 350 m/s so 1000 km/h), how would it affect our vision system? Could we see light travelling over long distances? Could we see "echo" in a mirror room? | [
"We already see light \"echo\" at its current speed. We just aren't able to perceive the time separation between the signal (a light-bulb turning on) and its echo (the reflection of the light bulb off a mirror). If the speed of light were much slower you would be able to tell the difference between a light-bulb tur... | [
"You wouldn't be able to see light moving around the room and towards you, because that light hasn't reached your eyes yet... your eyes can only respond to light that hits them, not light that's some distance away.",
"The effect would be, from your point of view, that things would light up much later than you'd e... | [
"I actually just read ",
"this article",
" today. Scientists have created a camera that takes pictures at a trillion frames per second. It gives you a good idea of what the world would look like if the speed of light were much slower."
] |
[
"If a chihuahua gets impregnated by a great dane, what keeps the puppies from growing too large inside of her? Is the female gene for size dominant over the male's?"
] | [
false
] | [deleted] | [
"Vet here - It's actually somewhat common for small breed dogs to have fetuses that are too large and cause considerable problems. This is especially true when there is only one fetus, and the body puts all of its resources into the one, making it too large. These puppies usually cannot be delivered naturally, and ... | [
"This may not be helpful at all, since the topic at hand is dogs, but here we go: In equines if you breed a large male and a small female, the mare (female) has various mechanisms to limit the growth of the fetus within her. Effectively, the fetus will grow to fit whatever space it can achieve - the bun will fit th... | [
"A chihuahua male can still impregnate a great dane female. ",
"There are actually quite a few instances in canines and other animals where a male of breed 1 impregnating a female of breed 2 will fail, while a male of breed 2 impregnating a female of breed 1 will succeed. ",
"A lot of factors come into play, li... |
[
"Why does water put out fire, if water is hydrogen and oxygen?"
] | [
false
] | null | [
"They're not just mixed, they're bonded. The flammability of hydrogen and oxygen is due to the energy given out when the two elements bond together to form water. If they're already water, that energy has already given out, and is unavailable. Water puts out fire because it stops fresh, available oxygen from reachi... | [
"Why can't I burn the ashes in my fireplace, if they're made of logs and oxygen? If logs and oxygen are flammable, how come when mixed they become fire retardant?",
"Why can't I burn the exhaust from my car, if it's made of gasoline and oxygen?",
"Why can't I burn [anything that has already been burned], if...... | [
"Also, water needs a lot of energy to be heated up. If you put water on a fire, water pumps this energy out of the fire."
] |
[
"Ages 1 to 4 are very important for brain development but yet most people can't recall anything from that time period. Why don't we remember our earliest memories?"
] | [
false
] | I know the brain is rewiring a lot of neurological pathways to determine the most effective route, but what stops us from remembering our early years? | [
"It’s not that we forget our earliest years, it’s that we don’t form memories in the first place. The term for this is infantile “amnesia”, but this is not actually a form of amnesia — that would require forgetting. As infants grow into toddlers, their brains grow fantastically quickly. So much so, that any pathway... | [
"One of my degrees is child development, and this is a great answer. Simple so anyone can understand and still spot on. "
] | [
"What you are taking about is autobiographical memory. Infants easily form other types of memories, including procedural memory (eg learning to walk), and semantic memory (learning what things are). Infantile amnesia is limited to autobiographical memories. There are lots of ideas as to why this is. One is a la... |
[
"Why is dineutron unstable?"
] | [
false
] | Edit to explain my question in more detail: Well I guess I should be more detailed in my question and that's my fault. Is there any theory that predicts why deuterium is stable but not dineutron? Is there some mathematical explanation from the strong force that explains why dineutron decays, and for that matter why fre... | [
"Yes, modern atomic theory can explain this quite nicely.",
"Deuterium is a proton and neutron forming the nucleus. Why is this stable? Why doesn't the neutron decay and just pop off?",
"Well to fully explain this you need to know about binding energy or packing fraction. Nuclear fusion as seen in stars is a pr... | [
"Well I guess I should be more detailed in my question and that's my fault. Is there any theory that predicts why deuterium is stable but not dineutron? Is there some mathematical explanation from the strong force that explains why dineutron decays, and for that matter why free neutrons are unstable? Or is it just ... | [
"This paper",
" places the binding energy between two neutrons to be around 70 keV. This is woefully smaller in magnitude than the change in energy done through beta decay.",
"However, this is about as good as I could find. A couple papers list binding energies of dineutron at ~3 MeV hypothetically in the early... |
[
"What natural things cause wildfires, besides lightning and volcanoes and meteorite impacts?"
] | [
false
] | Before people started using fire, what caused wildfires besides the 3 mentioned above? Also, any guestimates of how frequent each cause was or how much burned due to each of these? | [
"In at least ",
"one rare instance,",
" a landslide uncovered shale with high concentrations of pyrite. Oxidation of the pyrite generated enough heat to cause low-grade coal to burn.",
"American Geophysical Union",
" notes on the landslide.",
"Highly recommended on the subject: ",
"Tending Fire,",
" b... | [
"Also, large piles of decaying vegetation can combust from the heat of their own decomposition. This is why it's unsafe to fill a barn with bales of moist hay."
] | [
"Except for the ones you have already given, one that would come to my mind is hot weather. If you have really hot and dry weather, parts of some plants like pines and equivalent trees which contain terpenes and aromatic oils can inflame themselves, when they are hot and dry enough. Another way can be oil and gas s... |
[
"How exactly did the initial Chicago Pile nuclear reaction work?"
] | [
false
] | It seems, from my reading of the , that upon removing the control rods, the uranium atoms started absorbing the free neutrons and fissioning. How then, did they keep the pile from going supercritical (just the rods?), how did they determine the energy was being released, and where did the released energy end up? Also,... | [
"I'm going to talk about reactors in general here.",
"When the control rods are inserted, they absorb the majority of the neutrons and cause the reactor to be subcritical (non-self-sustaining).",
"When you remove the control rods, less neutrons are absorbed, and the number of neutrons detected in the reactor in... | [
"In a power reactor, prompt critical is avoided by design conditions. It's not impossible though. For example, during control rod ejection/drop events it is possible to have localized prompt criticality leading to the destruction of a small section of nuclear fuel. This is a postulated event however, and usually re... | [
"There was actually no radiation shielding at all, CP-1 ran at 1/2 watt max power. "
] |
[
"What would happen if you touched lava?"
] | [
false
] | It seems like a obvious answer, but would your arm be incinerated? Or would you be killed instantly? But the kind of lava that would be found just after an eruption. EDIT: Thanks for the awesome replies, and the interesting facts about lava! | [
"Aloha from the Big Island of Hawaii...",
"My house is only 15 miles from the active flow and we play with lava and cook in lava (I've posted on this in the past).",
"We use special kevlar/glass gloves (labsafety.com) that allow us to directly contact lava for about 20 to 30 seconds. This lets us do cool thing... | [
"Actually it is not 'cool' in terms of the lava temperature. In the photo where I am pulling the aircraft cable out of the lava tube - that tube was about 40 ft deep and 2/3 full of magma roaring like a liquid river. We are trying to get a sample from the tube (very hard to do). In that case the magma was over 20... | [
"Awesome reply.",
"Though I do feel compelled to add in a \"don't try this at home, kiddies\" for those who might ever encounter lava in the wild. Your lava is very cool -- barely glowing, and about to solidify. Lava can be a lot hotter, and a lot more unpredictable, and is best avoided unless you really know wha... |
[
"Does photon decay ?"
] | [
false
] | Hi, I was wondering recently if photon decay. Usually, structures are able to decay (such as molecule, atom, protons, etc...). More the structure hold energy faster is the decay process (again typically with heavy atoms) and can stabilise (iron-55 ?). So a heavy photon (very short wave lenght, high frequency and then h... | [
"As far as we know, they do not decay, nor does anything without mass.",
" they do decay, by having a very small mass (experiments show it must be below 10",
" kg if it exists) and decaying into the lightest neutrino (which would have to have a smaller mass in this scenario), they would have to have a lifetime ... | [
"I'm on my phone but look up j. heeck 'how stable is the photon'"
] | [
"Do you have a link to any papers on this? I'm interested in reading about the limits imposed by the CMB thermal spectrum."
] |
[
"There are notes between B and C or C and C#, right?"
] | [
false
] | null | [
"Not in the chromatic scale, no. The chromatic scale is what you find on all pianos and guitars, for example.",
"However, notes between them can be played, for example by bending on a guitar. The resulting notes are dissonant with the other notes in the scale though."
] | [
"There is an infinite number of notes between B and C, and C and C#. However, if you want to get technical I guess there'd be as much divisions between two chromatic notes as there are divisions of the Plank's length. So for example, between B1 (61.74 Hz; wavelength of 5,5884 m.) and C2 (65.41 Hz; wavelength of 5,2... | [
"432 tuning",
" is a chromatic scale that uses frequencies between the normal 440 chromatic scale. ",
"Here is a paper",
" talking about non-harmonic wind chimes. Also, there are ",
"enharmonic music scales",
"."
] |
[
"Can someone please explain the criticisms of the Myers/Briggs personality test?"
] | [
false
] | [deleted] | [
"The test is not accepted at all. It's popular in the business world and I'd say we keep it there. ",
"There's no scientist that would take that test seriously. It was developed by people with limited understanding of psychology, based on theories founded on absolutely no proof. ",
"Furthermore there isn't an... | [
"A key observation I have from taking the test online several times is that the questions may reflect temporary mood or life situation, rather than actual personality. For example, questions such as:",
"I have always been a notably extroverted person. But at my stage of life, long past the \"partying years\", wit... | [
"It's about as effective as a Buzzfeed quiz or knowing your Hogwarts house. Sure, maybe it tells you something useful about yourself based on your responses to the questions...but it's not exactly reliable.",
"If you re-take the test later on, there's a good chance you'll get a different result. And it isn't clea... |
[
"Had the chemistry or production of gasoline changed enough over the decades that gasoline from 1945 would not work in a modern car (new from 1945, not very old gas)?"
] | [
false
] | null | [
"Actually, much of the gasoline between 1920 and 1945 was leaded, meaning it included a compound called tetraethyl lead to boost octane performance.",
"Modern cars can not handle leaded gasoline and will die or foul up in response to it. Only in aviation fuel is the compound even legal anymore, and only some midd... | [
"In fact, the old gas pumps would not work in a modern car. During the transition from leaded gas to unleaded, when both were sold, the unleaded nozzles were made smaller as was the opening on the car. This prevented leaded gas from being put into an unleaded car. "
] | [
"Leaded gas lasted well into the 1970's, maybe even 1980's.",
"\nUnleaded gas was introduced in 1974, and for a long time gas stations sold both unleaded and leaded."
] |
[
"How do you optimize a rocket or space vehicle liftoff?"
] | [
false
] | I was thinking about the problem of lifting a space craft from the earth's surface to space and for some reason only just now realized that there's an optimization problem here (I think) and I'm curious what the model looks like for this and how it's performed. Suppose I want to lift a mass to an orbit of some altitude... | [
"A lot of simulations. There is essentially nothing that only has advantages or disadvantages, so you need to consider tons of options.",
"If you have a given rocket design and a fixed mission: Launch at full power - this is a very wasteful part of the flight and you want to gain speed as soon as possible. Accele... | [
"A faster ascent does take less energy - not because the gravity is stronger at lower altitude (the difference is pretty minor) but because the rocket spends more time fighting gravity. Think about the extreme case where the rocket is barely moving up - it will use up all fuel before it gets to any meaningful altit... | [
"Rockets launch at full power. The effect of air resistance comes into play for some, more fragile rockets which cannot withstand maximum frontal forces, so there is a point during ascend (maxQ), when engines are temporarily dialed back to reduce acceleration.",
"A few seconds later, the max power is restored in ... |
[
"Is there higher background radiation directly under the Aurora?"
] | [
false
] | If i'm not mistaken, earth's magnetic field deflect charged particles, and pushes them to the poles, creating the Auroras. Also if i'm not wrong, the background radiation can vary really highly from place to place, because it's affected by many variants. But is there any increase in the background radiation, if you sta... | [
"I actually just looked this up because of another recent post.\nThe short and skinny is that the aurora borealis ",
" be harmful to you but the rarity of such events is so low as to not be a concern.\nYour more immediate concern would be experiencing artic circle weather and temperatures."
] | [
"From the ground, one generally cannot measure radiation from a geomagnetic storm above background levels. There's sufficient atmosphere to act as very effective shielding, even at the poles.",
"At altitude, however, you can receive a decent dose. A trans-polar flight (for example, New York to Shanghai) during a ... | [
"VERY interesting! Thank you!"
] |
[
"How did/does a classical model of light (i.e., as waves) reconcile \"interference\" with Conservation of Energy?"
] | [
false
] | I understand that an interference pattern created by light doesn't violate Conservation of Energy because the overall intensity is the same as if there were not bands. But how can this be explained with a wave model as the dark bands (where waves "cancel" each other) would seem to say the energy from each wave just di... | [
"Whenever there is an interference pattern like this, where there are dark bands- there will also be extra bright bands. This is why the overall intensity stays the same. So, with interference, the bright parts are brighter than they would be without the interference. ",
"On a fun side note- this is different fro... | [
"The second part sounds wrong. A membrane driver as in headphones can't generate a \"DC pressure\".\nThe reason why NC headphones are not \"amplifying\" any sound outside the headphones is that the part where noise would be increased is simply inside the headphones (basically on the other side of the driver)"
] | [
"I don't know deeply about nc headphones, but if it truly does cancel the incoming wave, it makes sense to me. The energy has to go somewhere, intuitively it would be randomly into temperature. Which basically is just an increase in the pressure (DC pressure). That being said, it should be a small increase, the e... |
[
"Question regarding Quantum entanglement"
] | [
false
] | I'm trying to get a grasp on the following scenario: Consider replacing our Sun with spaceship equally massive. There are two entangled particles, one on the Spaceship, one on the Earth. Say we are to measure spin of these particles. The Spaceship is set up so that If clockwise spin is measured, It will move to a diffe... | [
"Let's change up your question a little bit. ",
"Assume we have a sun-sized spaceship which replaced the sun, and it was simply pre-determined that on \"March 13th, noon Greenwhich time, the space ship was going to move.\" Would you expect to feel the effects immediately or after 8 minutes? The correct answer is ... | [
"Here's the thing: unless I'm greatly misunderstanding you, the entanglement is actually irrelevant to your question. Imagine that instead of having two entangled particles with opposite spins, you have two sealed envelopes, one with a piece of paper in it that says \"clockwise\" and the other with a similar piece ... | [
"So basically, I was trying to argue, that If I know something will happen, It will happen immediately. What a waste of space I am. Thank you for the answer though."
] |
[
"Is hypnotism a legitimate practice/is there any evidence?"
] | [
false
] | Does hypnotism hold up in double-blind studies, etc.? I personally have a hard time believing that the power of suggestion could be as strong of an influence as it's often made out to be. | [
"There are a number of studies looking at hypnotism as a psychosocial intervention to reduce pain, with somewhat varying results. ",
"J Vasc Interv Radiol. 2008",
"Procedural hypnosis including empathic attention reduces pain, anxiety, and medication use. Conversely, empathic approaches which provide an extern... | [
"Everything I've read about studies on hypnosis all mention how difficult it is to perform a proper experiment due to the fact that hypnosis requires the patient to understand that they are being hypnotized and be willing to accept suggestions. And since that makes double-blind testing impossible, I guess it bother... | [
"Everything I've read about studies on hypnosis all mention how difficult it is to perform a proper experiment due to the fact that hypnosis requires the patient to understand that they are being hypnotized and be willing to accept suggestions. And since that makes double-blind testing impossible, I guess it bother... |
[
"How fast does dawn travel across land?"
] | [
false
] | How quickly does light travel across land as the sun rises? Or the reverse, how quickly does night "fall" across land? Is it possible to literally chase it using any existing form of human transportation? | [
"Circumference of the Earth is about 40,000 km. It spins around once every 24 hours. ",
"At the equator the speed of dawn is 40,000 km / 24 hrs = 1667 km/h, or about 1036 mph. ",
"At the geographical poles, this speed approaches zero. "
] | [
"And certain planes can easily travel faster than that. Also for the OP, the technical term for the night/day line of a planetary body is \"terminator.\""
] | [
"It depends on your latitude. Slowly at the poles, quickly at the equator. This is because it has to move all the way around the width of the earth at the equator, but a shorter distance at the poles. Rockets can definitely go faster than this speed at the equator."
] |
[
"Would a gun fire in space? And if so, would the bullet travel forever?"
] | [
false
] | [deleted] | [
"Actually, gunpowder, like rocket fuel, contains an oxidizer. As long as the firing mechanism works, the gun will fire. I dont know about the oils or the metals, but assuming that everything else is in working order, the gun will fire."
] | [
"Gunpowder, like rocket fuel, contains a nitrate based oxidizer built in. Assuming that the mechanism of the firearm will function in the cold of space, it will fire, and the bullet will go until it collides with something else."
] | [
"It should. I'm not entirely sure if the firing mechanism in the bullet would work, but I'm, fairly certain it would.",
"The bullet would get launched out of the gun at it's usual fire speed, and the gun would go off in the opposite direction at some fraction of the bullet's speed dependent on the ratio of the ma... |
[
"Would a persons feeling towards a drug inhibit it’s ability to work, like a nocebo?"
] | [
false
] | Does a medicine or tablet. E.g. panadol, have a lesser effect on a person if they are sceptical about it. even though the drug works would the effect be felt less by the body depending on the persons feelings toward either the person who administered it or the drug itself. Also if this has been studied what would the n... | [
"There was a research in Germany by a medical university where they looked at 31 empirical studies and found out that not only the nocebo effect exists (and it's called like that), but it's also causing an ethical dilemma for all the doctors and nurses. ",
"Why? Because if they inform patients as to the potential... | [
"Nocebo causes \"harm\" though, it doesn't refer to the drug simply becoming ineffective."
] | [
"Because nocebo does not mean \"no effect\" like OP asked, but comes from \"nocere\", to harm.",
"I'm not saying your info was incorrect, I just wanted to clarify where the term comes from. Because the question was whether positive effects can be nullified, which has nothing to do with the (factual) nocebo-effect... |
[
"After prolonged exposure to SSRIs do the effects on the brain remain once the administration stops?"
] | [
false
] | To me more specific, by effects I don't mean positive behaviors that a patient might have acquired while in a non-depressive period. I mean actual alterations from the substances the SSRI pills have. From what I know, SSRI's have been linked with an increase in neurogenesis, and since neurogenesis itself seems to be a ... | [
"Agree with above comment. Some are shown to have a better long term outcome but the research is very very limited. The idea behind that thought is that once we can chemically alleviate our depression, we start doing things that make us happy like working out, having hobbies etc which in turn also helps alleviate d... | [
"For major depression, we don't have good evidence for ongoing benefit beyond the period when the drug is taken, as contrasted with cognitive-behavioral therapy and similar treatments which do see sustained benefit well after the course of therapy is done. Exactly how that correlates to whatever's happening at a ce... | [
"Could that mean that a person taking SSRI's can, along with cognitive-behavioral therapy or just by having their symptoms of depression alleviated, have certain (possibly new?) pathways in their brain reinforced after a long exposure to both these treatments? Kind of like creating new habits, e.g. having a differe... |
[
"How would quantum computers change the field of cryptography?"
] | [
false
] | I know most modern encryption relies very heavily on factorization and that quantum computation would severely shorten the time necessary to solve factorization problems. If quantum computation is realized, what methods will likely replace factorization in encryption algorithms? Also, | [
"RSA would break. AES256 will remain strong. There are other public key cryptos that would still work."
] | [
"You can't make that kind of comparison. It's fundementally a new model of computing. "
] | [
"There's always ",
"quantum key distribution.",
" and one time pads. These would be completely unbreakable (unless our understanding of quantum mechanics is wrong), and interception of the key would be extremely difficult or impossible to do without detection.",
"The question, of course, is whether a practic... |
[
"Would a Roman be able to digest today's food? How about a caveman?"
] | [
false
] | Or going even farther back, would Lucy have been able to digest the stuff we eat today? | [
"I don't see any reason why they wouldn't, the genetic varieties of plants have changed quite a bit but the fundamental nutrients are the same. It would be like us eating food in a foreign country, you can easily get a tummy ache but you won't starve. ",
"The bigger problem would be the pathogens and any bacteri... | [
"Even chimps (and rats, for that matter) can eat human food. Actually the human digestive system doesn't look all that different from that of most other primates that don't eat a specialized diet."
] | [
"Of course rats (and many other animals common to areas with large human populations) are heavily adapted to survive on nutrients available in a human-heavy environment. So, in a funny way, it makes more sense for rats and roaches to eat like us than for chimps."
] |
[
"Could our solar system ever move into a large area of dust?"
] | [
false
] | If so would it superheat our planet from all the particles burning up in our atmosphere? | [
"Even \"high density\" areas of space are very low density. There's no way it would be enough to noticeably affect our temperature or environment. Also keep in mind that these \"dust\" particles are much less massive than the dust we're used to - I think most of them have less than a thousand atoms."
] | [
"I suppose our solar system could indeed move into a large area of dust. However even the most dense nebulae are still not particularly dense with particle densities of at max ",
"10",
" particles per cubic centimeter",
". Compare that to the 10",
" particles per cubic centimeter that the air we breathe con... | [
"No, even if it was a million times more opaque we would be fine - the dimming effect with regular interstellar gas/dust is still small enough to hardly effect light coming from many stars, even ones millions of times farther from us than the Sun is. Even in the densest of nebulae you can still see through tens of ... |
[
"Does exposing yourself to cold climate regularly make you more tolerant/less likely to become ill due to it?"
] | [
false
] | I caught a friend of mine riding his bike with nothing but a t-shirt and shorts on while it was snowing. He's a pretty smart guy and a premed student who knows his stuff. His reason was that he wanted to build tolerance for cold weather so he wouldn't be so effected by it. I called bullshit, but would like to know from... | [
"This is true, but the key word there is regular. On a biological scale, an hour a day of exposure is not enough for the body to use the resources to make more fat. Making fat deposits is costly to a person on a regular diet, so the body won't do it unless it's necessary. When you go to your cabin and you are livin... | [
"It seems that one can acquire cold-resistance through repeated exposure.",
"From an ",
"article",
" entitled ",
" (Harrod et al, 2002):",
"It has long been known that humans and nonhumans acquire tolerance to environmental stressors that challenge the thermoregulatory system. In particular, tolerance to ... | [
"I didn't read the whole thread but seems relevant. It's about people growing up in cold climate.",
"http://www.reddit.com/r/askscience/comments/11erzc/when_someone_grows_up_in_a_cold_weather_climate/"
] |
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