title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"How would someone derive a roll equivalent of a D20 using D6?"
] | [
false
] | Just a little math problem I've been trying to figure out in my head for a bit that I'm having trouble with. How would you get the closest to a D20 roll outcome using multiple D6 rolls? Is it painfully simple? | [
"If you're just looking for a convenient way to enact d20 rolls when you don't have an actual d20 around, the way I did it was this:",
"Roll the d6 once. Reroll it if it comes up 6. Multiply this number by 4. You now have 0, 4 ,8, 12, or 16.",
"Roll the d6 again. Reroll it if it comes up 5 or 6. Add this roll t... | [
"If you want to be rigorous about it, you could use a Markov chain to verify that the probability of each outcome works out to be equal to 1/20."
] | [
"Why would we do math when we have matlab?",
"rolls = zeros(1,20);\nfor i=1:1e7\n d1 = randi(6,1,1);\n while d1 == 6\n d1 = randi(6,1,1);\n end\n d2 = randi(6,1,1);\n while d2 >= 5\n d2 = randi(6,1,1);\n end\n d20 = 4*(d1-1) + d2;\n rolls(d20) = rolls(d20) + 1;\nend\nplot(rolls/1e7); axis([1 20 .049... |
[
"Since all emotion is in the brain, why do different feelings seem focused in different places?"
] | [
false
] | null | [
"I think the simple answer to this is that the body and brain release different hormones (in different proportions) in response to stimulus. These hormones act on body systems in different ways, which may be \"felt\". For example, stress is associated with cortisol, which acts on a vast array of body systems. ",... | [
"Both of those seem...unscientific. How can \"the body\" possibly \"feel\" independently of the brain when everything we know about feeling traces back to neurons? "
] | [
"This makes more sense to me. So it's just that different hormones are processes by different organs, thereby making different sensations? Cool. "
] |
[
"Does cooling really account for 30% of all CO2 production by humanity?"
] | [
false
] | Today, my professor for thermodynamics claimed that 'it is estimated that cooling (i.e. airconditioners, refrigerators and other cooling devices) account for 30% of humanity's CO2 production. It sounded like quite a bold statement to me, so I wonder: is there any truth to this claim? | [
"Ask him to provide a source for that statistic next time you see him. ",
"The number seems high, but not outside the realm of possibility considering ",
"this",
" site claims 40% of energy consumption is from buildings. He should be able to provide sources for his claim, or at least explain where he came up ... | [
"It seems slightly high, but the figure is well within the realm of possibility, especially if one includes heating as well. As an architectural rule of thumb, HVAC (Heating, Ventilation, Air Conditioning) systems account for roughly 40% of energy use in commercial buildings, and around 50% in residential buildings... | [
"Agreed. It's not unfathomable, particularly in regions of the world where it's always warm, such as Saudi Arabia. Air conditioners and other cooling apparatus use more power than all other common devices... even computers spend a large portion of their power on internal cooling.",
"I'd ask your prof for his so... |
[
"Is it possible for an insect to become obese?"
] | [
false
] | null | [
"Absolutely! \nThere has been many studies in flies involving feeding and obesity. I used to work with Drosophila Melanogaster (the fruit fly), and was studying the effect of octopamine. A study published in the Proceedings of the National Academy of Sciences of the United States of America (Long and Murdock, 1983)... | [
"Dissection of fruit flies? That's something that sounds like you need very steady hands for"
] | [
"Sadly, adult insect's cuticle cannot expand... The fat insect would indeed try to pack more fat underneath, but the cuticle would do its best to stop it. As a result, the inner pressure increases by a lot. Imagine yourself eating 3 pizzas but having a very tight belt wrapped around your belly, not allowing your st... |
[
"Are animals in nature capable of counting?"
] | [
false
] | This is a question I have been wondering about for quite some time and it continues to stump me. Its a fairly simple question and I'm sure(or at least I hope) that someone has an answer. But due to lack of any research and laziness to do so, I just decided to ask someone. Basically, I'm asking if animals in nature, suc... | [
"It would appear that the answer is yes, but it depends what you mean by count. Few animals actually have a symbolic expressions for abstractions like numbers, but many species do seem to have the ability to perform some mathematical operations. For example:",
"This study",
" involved researchers placing a ch... | [
"There have been quite a few studies of this. Here's one ",
"Quantity discrimination in jungle crows, Corvus macrorhynchos",
" and here's a journalistic ",
"overview of some others",
". It seems like there is evidence that various species have some sense of / ability with numbers although stating \"they c... | [
"There's a huge literature on this - ",
"here's a great review",
" (pdf). ",
"The first thing to know is that defining \"counting\" is harder than you'd think. There are actually quite a lot of different ways that humans, and animals, assess quantities and amounts. For example:",
"\"more/less\". Can you loo... |
[
"Is Mars more like a \"baby/early\" Earth, or a dead Earth?"
] | [
false
] | [deleted] | [
"There are a couple differences. Earth has large amounts of liquid water. Mars has some water, but it's mostly frozen at the polar caps. Also, Mars has no magnetosphere to protect it from solar wind which caused most of its atmosphere to be stripped away. It's less than %1 as dense as our atmosphere on Earth.",
"... | [
"\"We make our world significant by the courage of our questions, and by the depth of our answers.\" ~Carl Sagan",
"I actually thought that you asked an interesting question. Made me want to know the answer. :D"
] | [
"Thanks. After some thought I did think of it more as a dead Earth. Sorry If my question was a little ",
", I was watching Into the Universe and the question popped into my head."
] |
[
"Why do people sound different when they're reading out loud compared to when they simply speak?"
] | [
false
] | [deleted] | [
"Not everyone does -- people who read (silently) sufficiently fast and have sufficient interest in the subject matter (or just good acting skills) can make reading aloud sound perfectly natural.",
"It boils down to just how much of the text you're processing at once. People who read with a flat tone of voice are ... | [
"Many (most?) people, when reading text aloud, will have flat inflection and slower words."
] | [
"Different in what way? "
] |
[
"Is it possible for a bullet to cause enough force to knock someone back?"
] | [
false
] | Movies/video games have exaggerated in the past. But is it possible or just a complete myth? Even not possible/noticeable at low velocity/high caliber rounds? What if you had a vest on and the bullet did not penetrate completely through your body? | [
"Since momentum is conserved, the bullet can't impart more momentum to its target than it initially has. Since the recoil in a gun isn't enough to throw the shooter back, the bullet doesn't have enough momentum to throw a person forward. Mythbusters did a segment on this, and they showed that before special effects... | [
"This is mostly true, however, there exist shoulder-fired weapons that ",
" generate enough force to throw a shooter back, or knock a shooter over. Examples are rifles chambered in the ",
"20mm X 102mm Vulcan",
" round or home-built \"big bore\" loads like the ",
".700 Nitro Express",
". These sort of loa... | [
"It should also be considered that once a bullet achieves these energies, it is more likely that the bullet will go straight through or dismember the target. If the velocity is extremely high, it will go straight through like a high velocity rifle round. If the mass is increased like a connonball, it will just di... |
[
"Why does friction generate heat?"
] | [
false
] | I saw a post a while ago asking where the energy to move something under the force of gravity comes from, and it got me thinking. I was running my hand against a wall as I walked and noticed the heat generated by the friction, and started to wonder something similar; where does that heat come from? | [
"This is actually a really good question, so I'll do my best to answer it as thoroughly as it deserves:",
"Heat is, essentially, just a measure of the average kinetic energy of particles, in terms of their motion relative to each other (i.e. you wouldn't call us insanely hot because we're all on the earth moving ... | [
"All particles emit electromagnetic radiation as an approximation of a blackbody curve.\nMore energetic particles will emit EMR of a shorter wavelength, i.e. tending towards visible and/or ultraviolet light. Longer wavelengths are the result of cooler objects.",
"The amount of energy emitted is a function of the ... | [
"this is solid, but I was confused in a couple of places. ",
"Correct me if I'm wrong:",
"when particles become \"energized\" they radiate that energy outward towards equilibrium. For some particles this radiation is visible as light, for others this radiation is felt as heat. Friction transfers energy from on... |
[
"If the comet that is not going to hit Mars actually hit it, would it noticeably effect the orbit of Mars around the sun?"
] | [
false
] | I read about it on worldnews. | [
"No.",
"Even though the comet is quite big, it is a lightweight compared to Mars.",
"We do not know the mass of the comet but it might have a diameter of up to 50 km and is going at 55km/s.",
"Mars has a diameter of roughly 6500km going at roughly 25km/s.",
"At constant density the mass of an object is prop... | [
"But would it kill Curiosity?"
] | [
"The 55 km/s is relative to Mars and it's that high mostly because the comet is going to collide (or rather not collide) almost head-on with Mars. From ",
"the orbital parameters",
" I get a Sun relative speed of 35.6 km/s which is pretty much exactly the escape velocity at that distance from the Sun. In other ... |
[
"Why is the speed of light 299 792 458 m/s in a vacuum? Why not faster or slower?"
] | [
false
] | [deleted] | [
"The numerical value of the speed of light is totally arbitrary, and not a directly measurable thing. The only reason that we think of the speed of light as a dimensionful constant with a particular value is because historically humans have insisted on measuring time and space with different units. In light of rela... | [
"Does light travel one 'plankt meter' in one 'plankt second' ?",
"First it is \"Planck\". Second they are DEFINED that way, i.e. t_p = c*l_p by definition. Third the Planck units aren't necessarily absolute maxima or minima for anything. They are simply (related to) a curvature scale above which we can't do anyth... | [
"You're basically asking why 1 is 1, and not a little more or less than 1. The speed of light is a nature constant, that happens to be a certain way in vacuum, and there are no hidden factors that change the speed of light in vacuum.",
"The number seems super arbitrary, simply because it's expressed in units we a... |
[
"Atoms, Gravity, and Time"
] | [
false
] | [deleted] | [
"Does every object with mass have a gravitational pull? Do atoms have a gravitational pull? Does any object with mass alter the time around it (I'm thinking like a black hole)?",
"Yes, and by extension yes and yes (although not to the same extent as a black hole - which warps spacetime ",
" light can't escape -... | [
"Atoms have a very, very slight gravitational pull (far outweighed by things like electromagnetic forces they carry) and a gravitational pull will cause time dilation. This effect is negligible to the point of ridiculousness."
] | [
"Isn't it true that even electromagnetic radiation has gravity?"
] |
[
"Are there stars that orbit perpendicular to the galactic plane?"
] | [
false
] | In spiral galaxies, there is commonly a ‘galactic bulge’ of light. As most of us know, stars usually orbit around the plane, but is it possible for a large number of stars to orbit at (at least close to) a 90 degree angle relative to this? If so, how would that formation process have occurred? Or am I overthinking it a... | [
"Sure, in the bulge or the stellar halo of spiral galaxies, the orbits are ",
" random, so you get orbits in every direction (some bulges resemble elliptical galaxies in some ways). Whether it counts as \"a large number\" is up to you."
] | [
"You could take a whole course in galaxy morphology and evolution. It's a pretty deep subject.",
"If you haven't played Galaxy Zoo, that might be a good activity: ",
"https://www.zooniverse.org/projects/zookeeper/galaxy-zoo/",
"Here's a free textbook about it: ",
"http://astro.utoronto.ca/~bovy/AST1420/note... | [
"Your problem is that you've defined away the entire population of galaxies. \"Conventional spiral\" ",
" there aren't any weird out-of-plane features. If you just want to consider galaxies broadly, there are very many examples: ",
"https://talk.galaxyzoo.org/boards/BGZ0000004/discussions/DGZ1006810/"
] |
[
"What kind of field is the Higgs Field?"
] | [
false
] | Is the Higgs field a field describing the strength of a force at a point in space, like the Electromagnetic or Gravitational fields? If not, what kind of "field" is it? If so, which of the fundamental forces does it describe? EDIT: to another thread about the Higgs field and the Higgs Boson. In the discussion, someone ... | [
"Is the Higgs field a field describing the strength of a force at a point in space, like the Electromagnetic or Gravitational fields?",
"Not quite. It differs by being a scalar field (mass is not a vector quantity) and it has a non-zero vacuum expectation value.",
"I'm not sure the number 17 is quite correct. T... | [
"It seems to me that you are a bit confused about what a field is. Therefore I'll start from there and hopefully someone who knows more will post something about Higgs field.",
"Let's try to define a field.\nFirst we introduce an object called a manifold. It is nothing more than the place where your fields will l... | [
"First, as explained by others, a field is not necessarily something describing strength of a force, it can describe anything. Temperature is a nice example of a field: it takes some value at every point in space, and the value is a number (a scalar), so we call it a scalar field. ",
"The fields of the standard m... |
[
"Why do we feel nauseous when we spin?"
] | [
false
] | For example when you spin really fast in an office chair and begin to feel sick. What causes this? Does it or did it serve a purpose? | [
"How Stuff Works has a pretty good article on this:\n",
"http://science.howstuffworks.com/science-vs-myth/everyday-myths/question483.htm"
] | [
"If you spin in just the right way, you don't even need a real conflict",
"For most people that's a very slow spin and even then there are limits to how long you can spin even at a slower speed."
] | [
"If you spin in just the right way, you don't even need a real conflict",
"For most people that's a very slow spin and even then there are limits to how long you can spin even at a slower speed."
] |
[
"Potential energy and the conservation of energy"
] | [
false
] | This question has bothered me since I took physics in high school. The law of "Conservation of energy" states that energy in a closed system remains constant. So if you apply energy to lift a rock up twenty feet with a crane, where has that energy gone? Tt has now become "potential energy." My question is, isn't this... | [
"Think of potential energy as an energy storage, like in a ",
"weight-driven clock",
". If you give some mechanical energy to an object by moving it up, it'll store that energy (as potential energy), and give it back when it's allowed to go back to its original position. ",
"The law of conservation of energy ... | [
"The beauty of it is that the definition of potential energy does not have to have anything to do with the circular part of your definition. ",
"You can start by dropping rocks and measuring how much work they can do. Use them to drive in nails or turn a wheel and grind flour, or whatever you like. You will al... | [
"Nope. You're thinking too literally.\nLet's assume you take your rock and move it a metre into a vacuum. Two things will happen.",
"Assuming a 100% efficient system (no drag, no heat losses) what will occur is the following:",
"The gravitational potential energy gained by the rock will be equivalent to the w... |
[
"How does shooting down a nuclear missile work?"
] | [
false
] | I've always wondered how this works? With all the tension going on with North Korea and the threats of a nuclear attack on the US, if a missile were to be on its way to the United States surely it would be shot down before it reached, (I would hope) But how? and would whatever was underneath the blast, land or Ocean, b... | [
"The idea behind missile defence systems is that you smash it with an interceptor missile before it reaches its target. There's no danger of a nuclear explosion being triggered if you destroy an incoming nuclear missile in this way - causing the nuclear explosion itself requires a fairly precise orchestration of ev... | [
"ICBMs do, yes. They typically boost up to about 300km on their engine, and coast the rest of the way. During this flight phase they can reach around 1000km altitude, depending on how far they have to travel. They then re-enter the atmosphere over their target and, depending on the nature of the missile, make minor... | [
"Do these nuclear missiles actually go in to outer space then fall back down?"
] |
[
"Does exercise burn more calories at different parts of the day? What time of day is the body most efficient at fat burning?"
] | [
false
] | To specify cardio would be jogging/running for about 30 mins These articles are contradicting each other and both source valid papers. One says that the morning is best, the other says that the late afternoon is best. Please help me my poor brain is quite confused. | [
"You'll burn more fat at times when less carbohydrates are available for energy, it's that simple, and the first article says exactly that. Second article is not about cardio, it's about resistance training, so I don't know why you are trying to apply its facts to cardio."
] | [
"\"According to a February 2009 \"Flex\" magazine article by Jim Stoppani, a study conducted in 2005 at the University of Southern Mississippi followed 16 males for 10 weeks. Half of the participants trained in the morning before 10 a.m. and half trained in the evening after 6 p.m.. The evening group decreased body... | [
"Can you link to the \"study conducted in 2005 at the University of Southern Mississippi\" ? The link in the references isn't producing anything for me."
] |
[
"why can't we use capillary pressure for free energy"
] | [
false
] | [deleted] | [
"The water rising up from capillary action is actually ",
" - that is, the water rises so it has more intermolecular interactions with the walls of the container and itself, because it's a stable configuration.",
"That means whatever way you try to ",
" water from that configuration, you're ",
"."
] | [
"It's necessarily more, since you're moving the tube as well as overcoming the adhesion between water and the container. It's just not noticeable because the adhesive force of water is weak - so weak that it can only overcome gravity in a narrow tube, where the surface area versus volume of water is favourable."
] | [
"The increased gravitation potential is offset by the intermolecular forces between the water and the brick. One way to see it is that the enthalpy change in the formation of the water/brick bond is used to raise the water.",
"A clearer example would be the freezing of water into ice - forming the bonds and forci... |
[
"Confusion about what is considered a gene."
] | [
false
] | I'm learning genetics right now and it's a bit confusing, mainly genes and alleles. Lets say a plant has green leaves and it's crossed with a yellow leaf plant, it will produce some green leaf plants and some yellow leaf plants. Would that mean there are two genes involved or two alleles? | [
"The ",
" is the unit of genetic material (DNA) that encodes a trait - in this instance, leaf color.\nAn ",
", on the other hand, is a variation of a gene. G and g, for example, would be the two alleles belonging to the color gene.",
"This is, of course, a very simple example, and assumes that there is only o... | [
"Actually, genes are getting more difficult to define, not easier. Remember in the past, all we could do is experiments like those described in your question. However, when we discovered, characterized and started sequencing DNA we started to understand the molecular basis for genes and alleles. Sometimes the no... | [
"A good analogy would be a piece of clothing. You have many different genes, like you have many different pieces of clothing. Plants have a gene for leaf color and you have a glove. ",
"Gloves and genes can come in many different varieties. These are alleles. A plant has two sets of chromosomes and thus two ... |
[
"Is there a way to \"emergency-charge\" a battery?"
] | [
false
] | To clarify, what would have to be different, either on the battery's end or whatever you are using to charge it, in order to greatly increase the speed at which the battery charges? Also, if a battery was designed that could be charged regularly and "emergency charged" (even if the latter comes at a permanent cost to t... | [
"To fully charge a battery, you have to deliver a certain amount of energy to it. Power = Energy/Time, so to decrease the charge time, you have to increase the power. Since most batteries have a relatively fixed internal resistance, this would be done by increasing the current through the battery. This will work... | [
"Is it not bad for the overall longevity of the battery to charge it too quickly? ",
"Is that a myth, or is it something to do with the higher temperatures involved? Or something else? "
] | [
"IANA electrical engineer, so I don't know. It very well may be."
] |
[
"Do we see diffraction in gravitational lenses?"
] | [
false
] | The lens-angle formula, as Wikipedia gives it, doesn't account for photon energy. I know newtonian objects all fall at the same speed regardless of mass, but can we say the same about photons? I guess the question comes down to: Does the equivalence principle hold for light? | [
"I think you're mixing up a few terms here. I think you're asking about dispersion of photons, like how light passing through a prism breaks up into components because each frequency is bent by a different amount. In that case... no, gravitational lensing does not have a frequency dependence in how it bends light. ... | [
"It's the standard explanation for objects falling at the same rate even though the gravitational force on an object is proportional to the object's mass. \nSince more massive objects experience more grav-force, you might intuitively expect them to fall faster, but inertia (resistance to that force) is also proport... | [
"ah yes, I usually think of it in terms of the weak equivalence principle, I guess. That acceleration is indistinguishable from gravitation. I didn't see how you were applying it for light then above.",
"That being said, yeah tests of energy-dispersion are broadly conducted for a couple of reasons, one of which i... |
[
"Why did scientists in the '60's think that Mars was covered in vegetation?"
] | [
false
] | Text from an article in Science Digest in 1963 Mars has pronounced seasonal variations, with the seasons about twice as long as those on earth, during which the surface temperature ranges from -120 to +30 degrees Celsius. When the northern hemisphere is in the "winter" season the dark green areas change to brownish gra... | [
"I had to dig a bit for that bit of historical trivia!",
"This is what I found:",
"Sinton, W. M. (1959). Further evidence of vegetation on Mars. Lowell Observatory Bulletin, 4, 252-258.",
"Sinton, W. M. (1957). Spectroscopic Evidence for Vegetation on Mars. The Astrophysical Journal, 126, 231.",
"Schlumberg... | [
"Isn't it mind blowing to compare space science then and now? I wonder what we will achieve in the next century if science can keep this progress rate!"
] | [
"It's particularly interesting to me that we went from thinking there was abundant life to determining there was no evidence for it with such depth that now if we did actually find life it would be amazing news."
] |
[
"Why is it that superficial wounds don't heal 100% sometimes? (details inside)"
] | [
false
] | I'm not sure if this is a generic anatomy question, or something specific to my (somewhat dysfunctional) body but here it goes: I rollerblade. I fall often. My hands take the brunt of the damage, but sometimes I land on other body parts. Some wounds heal 100%, you could never tell they were there. But I have a few that... | [
"It can be difficult to determine whether you have damaged the epidermis (where the tanning takes place), as it does not necessarily affect the healing process as such.",
"One of my friends fell and hit his shin on a small piece of rubble, it did not break his skin (it barely bruised) and yet, to this day he has ... | [
"Well, my limbs are the ones getting hurt most of the time. I'd say it's mostly random, and I haven't really had that many wounds to be able to pinpoint a pattern. I have small ones in both of my legs, some a little bit more than a month old, others more recent, but left colored patches. I have one in my thumb's kn... | [
"I have Raynaud's but I never have problems with areas of poor circulation healing. Even the most superficial scrapes on my legs can leave a scar and deeper cuts leave nothing. I think you're normal! "
] |
[
"When we say that the faster an object travels through space, the more mass it gains, is it because it interacts more and more with the Higgs field?"
] | [
false
] | null | [
"This is a common misconception. The faster an object moves, the higher its inertia is with respect to you. The rest frame mass of the object remains the same. Some people call this increased inertia \"relativistic mass,\" but it's a concept that leads to all sorts of confusion, so we don't use it anymore. Less use... | [
"What a wonderful question! Accelerated frames in QFT ",
"are really weird!",
" I have never read any elucidations on this, but to be fair I haven't looked around too much yet. One immediate consequence pops into my head, in accelerated frames, you no longer are able to have an invariant vacuum expectation valu... | [
"This means the higgs mechanism doesn't bother you based on your speed, because the physics doesn't change when you change inertial reference frames.",
"Does the mechanism change when you are in an accelerating frame?"
] |
[
"How quickly does a SCRAM happen?"
] | [
false
] | I don't know the situations for when a nuclear reactor needs an immediate shutdown (or how often that comes up) but I do know that once a reactor is packed up with control rods, the next step is to cool the reactor down. How quickly are control rods inserted into the reactor, and does the speed or method vary with reac... | [
"Fast.",
"The control rods are held out of the reactor by an active mechanism. When the button is pushed, or when the power fails, that mechanism lets go and the rods are let loose into the core. ",
"The exact setup does vary a bit by reactor design. In some reactors the rods are suspended out of the core by el... | [
"As they're inserted, they're already absorbing the neutrons that are needed to sustain a chain reaction, and so the reactor power drops off almost instantaneously. By the time the rods are in all the way, the reactor power will have gone down by something like 95%.",
"Just a quick note: While this is how it shou... | [
"Than again chernobyl bypassed a lot of its safeties and was a really old design, they also boosted the performance quite a bit this together with the missing safety protocol, unfinished maintenance and human error made it meltdown.",
"Modern generation gen2 3 and 4 shouldn't do this. "
] |
[
"How is energy used for sudden actions stored in the human body?"
] | [
false
] | I'm assuming that the energy produced through digestion is stored somewhere, which allows it to be used at a very short notice, e.g. suddenly sprinting. How is it stored, and what allows it to be ready for use so quickly when the body's power requirement is drastically increased? | [
"The main source of cellular energy in humans is ",
"adenosine triphosphate",
" (ATP). ATP can be produced via a number of metabolic processes, such as ",
"glycolysis",
", ",
"citric acid cycle",
" and ",
"oxidative phosphorylation",
". The basic principal of these interconnected metabolic pathways ... | [
"What ",
"/u/Jazzeater",
" explained in his ",
"comment",
" is correct. However, there is another mechanism that is very relevant to your question, and that is the very fast regeneration of ATP through phosphocreatine.",
"http://en.wikipedia.org/wiki/Phosphocreatine",
"Phosphocreatine can anaerobically ... | [
"Exactly. This is the answer that OP was looking for. The order of substrate use for muscle action is: ATP > Phosphocreatine > Glucose/Glycogen in Glycolysis, and then it gets fairly complicated and depends on duration of exercise, intensity of exercise, and nutrition status (substrate availability). Basically burs... |
[
"What does it mean to say this universe is \"flat?\""
] | [
false
] | [deleted] | [
"Well, there is no outside. At least, we don't expect there to be an outside. Moreover, there are no words to describe what it would \"look like\" because our languages developed to describe the sorts of things we can see, and our vision evolved to interpret 2-dimension images of uncurved 3-dimensional objects (whi... | [
"That it isn't curved. Specifically, that initially parallel lines (marked by light-rays, perhaps) remain parallel indefinitely.",
"Consider the surface of a sphere. Imagine you start two paths on the equator, both heading due north. They are thus parallel to begin. But they immediately ",
" to be parallel and ... | [
"To add just an intuitive point to RM's post, the important message is that this thing we call \"curvature\" (or its absence, \"flatness\"), which is familiar in the 2-dimensional case, also exists for all higher dimensions.",
"To really \"feel\" the curvature of a 2-dimensional object, we need to be able to visu... |
[
"A question for /u/AsaChemicalEngineer"
] | [
false
] | null | [
"One of my roommates... who? Are you sure you heard right? ",
"I don't know what AVATAR is though. Sorry I can't be of any help."
] | [
"No problems, just surprising on my end. Sorry I can't be of any help. I don't do any cyber security work. If you have a general computing question (that isn't nessisarily about a single system) feel free to rephase and ask that on the ",
"/r/AskScience",
" forum."
] | [
"Sorry. I believe I have the wrong mod then. AVATAR is an advanced system that can detect eye movement, passport authenticity, pupil dilation, etc. It was displayed at an Arizona GenCyber camp at University of Arizona. Sorry for wasting your time."
] |
[
"Is it possible that blowing your nose to relieve sinus congestion could have more drawbacks than benefits?"
] | [
false
] | I've read a few articles linking blowing your nose to higher possibility of a stroke due to a brain hemorrhage. I was just curious if anyone had any knowledge on the subject. Obviously it is commonplace to blow your nose when you are sick, but I sometimes wonder if it is counter-intuitive to the body's reaction to swal... | [
"Daily mail health articles are less medically accurate than a nice cheese sandwich.",
"If this is all you've got to go on I wouldn't worry about it. I don't know anything about the specifics of this article though. "
] | [
"Well, based on the description in the daily mail",
" it's only a short term risk induced every time you blow your nose, and they're not looking at long term complications. ",
"I did have quick search on google scholar for the original article, but I can't find it."
] | [
"Found ",
"this link",
" in the related ",
"science daily",
" article."
] |
[
"Why is it that some substances are metabolized according to half-life (caffeine) and others by set amounts (alcohol)?"
] | [
false
] | Is either more accurate, or are these just rules-of-thumb for lay people to use so they don't get too drunk or caffeinated? | [
"The difference is essentially first-order vs. Michaelis-Menten kinetics.",
"First-order reactions occur at a rate proportional to the concentration of the reactant. This tends to be true for the elimination of caffeine. This means that the elimination rate of caffeine is directly proportional to its concentratio... | [
"The answer does address a fundamental limitation of enzymes though, which is simple saturation (overwhelming the enzyme with substrate, while the catalytic rate is maximized. Enzymes can only work so fast). "
] | [
"The answer does address a fundamental limitation of enzymes though, which is simple saturation (overwhelming the enzyme with substrate, while the catalytic rate is maximized. Enzymes can only work so fast). "
] |
[
"My biology teacher told me that our eyes generate a new frame every 1/16th of a second. So 16 FPS? Is that true?"
] | [
false
] | That seems unbelievable! If that's true, why can I tell the difference in video games between 60 FPS (eg. Call of Duty) and 30 FPS? (eg. BF: Bad Company 2) | [
"That's not really true. Human eye's don't have frames or frames per second the way that video recordings or video games do. When enough light hits a photoreceptor in the eye, triggers and sends a signal to the brain, but then the photoreceptor needs to refresh before it can be triggered again. The limiting factor ... | [
"your eyes don't exactly see in \"frames per second\". the closest thing to anything regarding FPS is that images usually persists for roughly 1/25th of a second on the retina. it is really wrong to assign an FPS value to the human eye, but if i were to do it because there was a gun to my head, i would say 25-30 FP... | [
"As I understand it, the main point is that your eyes don't take snapshots synchronized with a clock (not the thing on the wall, just an on-off oscillator). Rather, lots of different places on your retina send lots of different non-synchronized messages to your brain.",
"Think of it like this: you have a bike in ... |
[
"Theoretically, would it be possible to create an atmosphere on the moon?"
] | [
false
] | Would it be possible to create and sustain a breathable atmosphere on the moon? Of course, this is just asking if it is theoretically possible, because that would require a very large amount of oxygen. But would it even be possible to create an earth-like atmosphere, if we had the resources? | [
"This is sort of simplistic.",
"Titan, one of Saturn's moons, has a surface gravity less than that of our moon. Yet it has an atmosphere 1.5 times as dense as Earth's. Clearly, it is not gravity alone that is the problem. Objects with less gravity than the moon can hold massive atmospheres. We have an example in ... | [
"This question was asked before, and I answered it in some detail ",
"here",
".",
"I also answered a related question about how much gas would be needed to create an earth-normal type atmosphere on the moon ",
"here",
"."
] | [
"(LAYMAN)",
"Presumably also important: Titan lies within the ",
"magnetosphere of Saturn",
", but the Moon is about 4 times farther out than ",
"Earth's magnetosphere",
"."
] |
[
"Is the solar system in equilibrium, or is it unstable?"
] | [
false
] | Have we modeled how the planet's orbits will change as the solar system ages? Are planets gradually going to collide with one another, float off into space, or just remain* in their current orbits? *until the sun goes nova | [
"Any gravitational system involving more than two objects is unstable. But often, this instability will only manifest over very long timespan. Moreover, it's usually chaotic - which means that absolutely tiny changes to the initial conditions (like moving Mercury 1m to the left) can have significant changes on the ... | [
"When you say long timespans, how long are we talking?\nAnd I'm also assuming that as far as you know there isn't a time accelerated model of our solar system that could show possible changes?"
] | [
"For the planets in the solar system, billions or tens of billions of years.",
"The problem is that it's not possible to accurately predict the effects of gravitational instability on the solar system over long time-scales; that's what we mean when we say it's a \"chaotic\" system.",
"For example, a solar syste... |
[
"If our lungs are in our chest why does our stomach expand when we breathe in and not our chest?"
] | [
false
] | null | [
"If your chest doesn't expand, you are doing it wrong. The diaphragm does push down on the belly and pushes out the contents, but your abdominal muscles are auxillary (secondary) muscles of respiration. Your belly will passively outpouch, but you shouldn't be breathing primarily with your belly.",
"Think of the r... | [
"Your chest should expand somewhat when you breathe (at least mine does). However, your abdomen also moves outward because of your ",
"diaphragm",
". This muscle sits below your lungs and contracts, pushing into your abdominal cavity, to \"pull\" air into the lungs. In case the wiki isn't clear, I found this... | [
"It's fine to use accessory muscles when exercising or singing. But you should have to depend on those for normal passive breathing."
] |
[
"Is there a point where too much muscle is bad for your body?"
] | [
false
] | Correct me if I am wrong, but the heart works extremely hard in cases of obesity, which is a bad thing. Would there be a point that the heart would work equally as hard to sustain a certain level of muscle in the body? | [
"Everyone seems to be missing the point of the question, so I will rephrase in hopes have we can get an answer. I am also curious about this question. ",
"While maintaining a healthy body fat percentage, can a person build so much muscle it can effect their health? Why?"
] | [
"I believe the simplified answer would be no. Unless you are a mutant or intentionally mess with its function, ",
"myostatin",
" works to limit the total amount of muscle a person can have. Getting there is a different story, but even in the few cases of natural mutations having up to 40% more muscle mass does... | [
"You could still have a high muscle mass and a high enough body fat ratio as well."
] |
[
"The liver breaks down alcohol, but what does it break it down into?"
] | [
false
] | Basically the title | [
"Ethanol (drinking alcohol) is metabolized by the enzyme alcohol dehydrogenase into acetaldehyde. The same enzyme then further metabolizes acetaldehyde into acetate. ",
"Methanol (moonshine runoff) is metabolized into formaldehyde and then formic acid, by the same enzyme",
"Isopropyl alcohol (rubbing alcohol) i... | [
"Mostly correct.",
"Alcohol dehydrogenase (ADH) converts alcohol to acetaldehyde. Then acetaldehyde dehydrogenase (ALDH) converts acetaldehyde to Acetate.",
"The reason people have different alcohol tolerances is due to different levels of ALDH expression. Asians have really low levels, hence Asian Flush Syn... | [
"It should be said the treatment for methanol poisoning is ethanol, but only because if your body is flooded with ethanol it dilutes the methanol enough so the methanol is converting the formic acid more slowly because it needs to convert the ethanol as well, so it doesnt build up quickly enough to hurt you."
] |
[
"I'm looking for a scientific study showing a difference between how right and left wings brain works, could anybody help me?"
] | [
false
] | I'm not quite sure about the specifics, but anything on the matter would be appreciated. Thanks. | [
"http://www.ted.com/talks/lang/eng/jonathan_haidt_on_the_moral_mind.html"
] | [
"That's exactly what I thought of, nice work. "
] | [
"Not sure anything like that has been done. The best you can do are things like this:",
"http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W4M-4TKXD92-1&_user=10&_coverDate=12/31/2008&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1308047166&_rerunOrigin=scholar.google&_acct=C0000... |
[
"How do scientists know how many elements there are?"
] | [
false
] | I've always been a huge fan of science fiction and space travel in particular. My most recent science fiction obsession is the Mass Effect series in which an imaginary element named element zero is used to generate dark energy and allow extreme faster-than-light speeds. I've always heard that scientists know what every... | [
"Each element in the periodic table represents a nucleus with a unique number of protons. 1 proton is hydrogen, 2 is helium etc etc, most people know this about the elements, so I say this just to demonstrate what differentiates one element from another. ",
"Now, there is a key reason why you can't just keep ad... | [
"Each element has a unique number of protons(and electrons), starting with hydrogen at 1 going up to uranium with 92. Beyond uranium the elements become unstable and are usually man made, if they were to somehow be created naturally they decay rapidly into other elements, usually in fractions of a second."
] | [
"You're question isn't stupid, xieish is just an ass. There most likely are no planets made of elements we don't know about because we know of all the elements up to 118 and only up to lead-208 are stable ones.",
"There could possibly be an island of stability up in the really high z numbers, but we have no evide... |
[
"Why do the significant majority of Southeast Asians have light skin and black hair?"
] | [
false
] | null | [
"Is it not true then that the black skin tribe in Africa became the dominant group because their black skin gave them a reproductive/survivability advantage? "
] | [
"Is it not true then that the black skin tribe in Africa became the dominant group because their black skin gave them a reproductive/survivability advantage? "
] | [
"Technically, Japan is generally considered to be East Asia. Southeast Asians are countries like Malaysia and Thailand, and they're generally darker. Japan's about at the same latitude as Spain, so there's no particular reason they should be much darker than that. Japanese popular culture also skews towards pref... |
[
"How fast does rain fall?"
] | [
false
] | How fast does rain fall from the sky. I do not think that rain would be falling extremely fast because raindrops have low mass, and they do not hurt or sting when they hit you. Is there any kind of radar gun that could be used to measure this? Thanks for reading. | [
"What you are looking for is the drop's ",
"terminal velocity",
" and it should be fairly easy to estimate with the formula on wikipedia. You'll have to look up some constants and chose the size/shape of your drop. The ",
"drag coefficient",
" is probably the most annoying thing to pick, but I think it'd be... | [
"Thanks for that. I’m not any good at physics so I am not going to try to find the answer."
] | [
"This is an old post, but I wanted to point out that raindrops are not streamlined. They are typically spherical, but large drops grow more oblate rather than streamlined. ",
"source"
] |
[
"What is the Moshinsky atom?"
] | [
false
] | null | [
"Do you have some more context? Where did you hear about this?"
] | [
"Thank you for your reply!",
"The specific context is this ",
"paper",
".",
"I am familiar with some of the math behind open quantum systems i.e., Quantum Markov Semigroups. ",
"I would like to understand what is the \"Moshinsky atom\" in the sense of:\nWhat does it describe? (ELI5)",
"Is it a model ... | [
"Just from looking at the Hamiltonian given in the paper, it looks like an \"atom\" where the two constituent particles interact via a harmonic-oscillator-like interaction. It looks like you have two particles placed in some external HO potential, which also interact with ",
" via a different HO potential.",
"B... |
[
"How did multicellular life appear?"
] | [
false
] | null | [
"This is a big question in biology with no definitive answer. Paleomicrobiology (i.e. the study of ancient microscopic life) is a tricky field because microbes don't fossilize the way macroscopic life does, and Precambrian rocks are relatively hard to come by. Paleontology is not my specialty, but to my understandi... | [
"It didn't just appear, multicellular life started out as small colonies of simple cells called protists. This tactic proved very useful through natural selection, and so multicellular creatures started growing in size, in complexity, and their cells started to specialise.",
"However, the exact reason or the turn... | [
"You're right, I totally misinterpreted that in my reply. Thanks for the correction!"
] |
[
"How do you calculate the radius of a large explosion?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/estimation",
"/r/theydidthemath",
"guidelines",
"/r/askscience",
"If you disagree with this decision, please send a ",
"message to the moderators."
] | [
"The question involves performing a calculation.",
"No, the question asks for the formula so I can do the calculation."
] | [
"Which is similarly off-topic, for the same reason, and ",
"more",
". Specifically, asking ",
"/r/askscience",
" to do your research is not something we allow.",
"Cheers."
] |
[
"Where can I go to find reliable sources for global warming?"
] | [
false
] | null | [
"Reputable governmental science organizations and professional science associations relevant to climate change include:",
"The ",
"National Oceanographic and Atmospheric Association",
"NASA's climate change page",
"The ",
"Environmental Protection Agency",
" ",
"The ",
"Royal Society",
"The ",
"... | [
"Awesome, This is exactly what I needed! Thank you!"
] | [
"I also recommend searching through ",
"/r/AskScienceDiscussion",
". We've had a few really great climate change posts there. "
] |
[
"How do directions work in space?"
] | [
false
] | Say I'm standing on the moon and want to go Mars. How is it calculated? I'm imagining that you calculate the movements and time needed and then you get a vector that points you in the right direction. How does this vector work? What does it relate to? Is there a standard way to get from one (moving) point to another in... | [
"There's nothing special about directions in space as such (maybe if you get into general relativity but I don't suppose you meant that). Mars is right in the direction where it seems to be. What I think you're asking is how the orbits work. That is, if you are on the Moon and want to go to Mars, with a spaceship t... | [
"15 people beat you to the ",
" reference. No need to post it again; it only makes more work for the mods. Thanks."
] | [
"If you want to get an intuition about orbits in a fun way, I highly recommend trying the Kerbal space program game.",
"Along those same lines, ",
"Orbiter",
" is another good space simulator, it has a steeper learning curve but also has ",
"a lot more depth",
"."
] |
[
"What enviromental conditions existed that allowed for Megafauna to exist, like Mammoths and Giant Sloths?"
] | [
false
] | Specifically I am talking about Pleistocene Megafauna, which includes: and many others. I make this distinction as I am aware that Megafauna exists today, however I am interested in the larger ancestors to many types of animals that are around today. I would like to know what conditions were original around to allow ma... | [
"The evidence is strong that humans caused the decline of megafauna. These species had already endured many glacial-interglacial cycles, but in each case the arrival of humans preceeds the extinction of nearly all large mammals. Importantly, humans arrived in Australia, Madagascar, and the Americas at different tim... | [
"The only animals for which oxygen has been conclusively correlated with size are invertebrates."
] | [
"The only evidence I can find that suggests there is a relationship between mammalian megafauna size and environmental conditions is ",
"Bergmann's rule",
" but that doesn't necessarily provide insight into why Pleistocene megafauna died out. I've read some arguments suggesting that the increasing heat post-ice... |
[
"Can you measure the local curvature of space by measuring the size/shape of the cone of reflections between parallel mirrors?"
] | [
false
] | I guess what I'm asking is, would the decay in the size of the reflections between parallel flat mirrors fixed together at an arbitrary distance change measurably in differently curved space? All other things being constant, the value of pi would change as the horizon would advance or recede? The distance between refle... | [
"I think it would. You'd effectively be looking at gravitational lensing, made easier to see by multiple passes through the space between the mirrors. (Assuming you're in our universe where curved space is because of GR; in a hypothetical other curved space that happens to have mirrors in it, you'd be measuring the... | [
"Yes, this is a way to measure curvature. More generally, two objects dropped together in free fall (=under no force other than gravity) will not remain parallel as they move through a gravitational field. The distance between them will change, and that distance is given by the ",
"geodesic deviation equation",
... | [
"That's effin cool, thanks! :D"
] |
[
"What happens when a sperm and an egg of two different species come in contact with each other? Does the egg not even let the sperm in, or does it let it in but then the zygote DNA doesn't fuse? What happens with the conception of hybrid species like ligers?"
] | [
false
] | null | [
"So, several things probably prevent this from happening. One, there are certain cell-surface proteins required for the sperm and egg to fuse correctly, that result in proper recognition. If these differ, the two cells are unlikely to meet correctly or induce the acrosome reaction, where the sperm basically burns i... | [
"If you don't mind a little off topic (not really animals) but plants actually manage this all the time, They have an amazing cross-breeding history due to a duplication of chromosomes called polyploidy, which means that instead of say, 6 chromosomes you have 12. If you have that mutation (can occur during meiosis/... | [
"Mitosis is generally not the limiting step in species isolation post fertilization events - meiosis is. If the sperm and egg somehow merge from two different species the resulting embryo is capable of undergoing mitosis because the chromosomes are not required to pair up along the cell axis for division. Each chro... |
[
"Big Bang temperature and density."
] | [
false
] | [deleted] | [
"There are no such things as \"pure\" energy, much like there are no such thing as \"pure\" mass. ",
"Particles can have properties such as mass or energy, and a bulk of particles with high (thermal) energy has a high temperature."
] | [
"To piggy-back on Ampersand55's correct answer ...",
"But at the same time they say that no matter existed but only energy.",
"They are, unfortunately, wrong, as far as we can tell. The matter that existed may not have existed ",
", but \"something\" was certainly there.",
"Energy doesn't have a material e... | [
"There was a good post around here a while ago about just this, energy is just a number that helps us keep things in order. So far, theory and observation tells us that no matter what, this number is conserved."
] |
[
"Why does our vision blur?"
] | [
false
] | null | [
"Because you are drunk. Really though perhaps a little more info? "
] | [
"I think what Gamefox24 means is please provide more information about the question. When, for instance."
] | [
"I think what Gamefox24 means is please provide more information about the question. When, for instance."
] |
[
"If someone's receiving cancer treatment and given the all-clear, is it inevitable that they'll get it again at some point if they live long enough?"
] | [
false
] | I've always had the notion that once you get cancer, it's not a question of it'll come back, but when. I'd be interested in how right or wrong my assumption is. Is there any data on the percentage of cancer survivors who remain cancer-free for the rest of their natural lives? I assume it would vary depending on the typ... | [
"There are cancers we can cure and some that we can't. It depends on the cancer, and for some cancers we can cure some stages and not others. The data for long term cancer-free survival is really dependent on the cancer and stage. For one example, ~85% of standard risk childhood leukemias can be cured. That means t... | [
"Relevent XKCD:\n",
"http://xkcd.com/931/",
"Alt text has explanation of the final frame."
] | [
"Cancer isn't really a single condition, you have to think of it as a grouping of conditions, and it would depend on what type of cancer. "
] |
[
"Has anything actually reached 0 Kelvin? And if not, is it thermodynamically possible?"
] | [
false
] | And I don't mean 0.0028 Kelvin, I mean 0.0000000000 to infinite significant figures. Thanks :] | [
"It is not possible. But you can get arbitrarily close. The record I believe is several hundred trillionths of a kelvin."
] | [
"To add to what's been said, it's not possible because a state in zero temperature is a state whose particles all have exactly zero energy. However, quantum fluctuations will ",
" cause there to be a slight amount of energy, even in a vacuum, and so there will always be a corresponding non-zero temperature"
] | [
"Another way of putting it would be the Uncertainty Principle, right? Zero temperature means 0 energy, which means being able to know both position and momentum to arbitrary precision."
] |
[
"What is intrinsic curvature?"
] | [
false
] | [deleted] | [
"We call it \"curvature\" really only by analogy.",
"Consider some two-dimensional surface in three-dimensional space. Like the surface of a sphere, say, or a hyperbolic paraboloid, or whatever.",
"Every point on that surface can be described in terms of ",
" coordinates. If you imagine a sphere hanging in sp... | [
"Intrinsic curvature means two things. One is that space doesn't have to curve into anything, which you seem to understand pretty well. So I'll gloss over that, even though it's usually the question.",
"Intrinsic curvature also means that the distances between points are affected by the curvature though. You can ... | [
"Very very simply, yes. It's a bit more complex than that, for reasons that you can see clearly with just a little examination. For example, in the case of the metric of the cylinder, you can map it to a plane, but you must ",
" two edges of the plane. That is, you must say that the curve of constant longitudinal... |
[
"Is a water soluble calcium salt less likely to be ionized in stomach acid than a poorly soluble calcium salt?"
] | [
false
] | [deleted] | [
"Aah I see\nIm wasn't familiar with the product you're talking about, so yeah... xD",
"But I get it now.",
"The Ca form would likely indeed ionize inside the stomach, but then it would need to be hydrolised by stomach acid into a organic compound to get absorbed into the body. \nOsmosis into the body will likel... | [
"You answered my question. No, I was speaking of HMB-CA specifically, a calcium salt of hydroxymethyl butyrate, which also has another form, Free Acid HMB sold at a much higher price. I needed to know if the HMB-CA, which is water soluble, loses all the calcium through ionization, leaving behind HMB-FA, what this s... | [
"You answered my question. No, I was speaking of HMB-CA specifically, a calcium salt of hydroxymethyl butyrate, which also has another form, Free Acid HMB sold at a much higher price. I needed to know if the HMB-CA, which is water soluble, loses all the calcium through ionization, leaving behind HMB-FA, what this s... |
[
"Why does rubbing alcohol feel slightly warm to the touch when I pour it over my skin?"
] | [
false
] | null | [
"It does? Without testing this right now I would say it should feel slightly cold due to rapid evaporation. Compare it with water and report back."
] | [
"This was my understanding, and I just tried it out with some IPA I had lying around. This is common with other alcohols as well, such as ethanol, and what happens is that the alcohol draws heat away from your skin in order to give it energy to evaporate. This is the reason why they evaporate much quicker than wate... | [
"Yup, it does. Every single time I've used it my entire life."
] |
[
"Why are trans-unsaturated fats viewed as more dangerous than saturated fats?"
] | [
false
] | [deleted] | [
"I used to teach organic chemistry, and am studying medicine now. As a principle, the body can be either incredibly selective, with enzymes only binding one skeletal structure but not a similar one. Alternately, they can be absurdly nonselective. It's messy. ",
"In this case, it remains somewhat unclear exactly w... | [
"In a biochemistry class last year I seem to remember that trans-unsaturated fats are not made in biological systems. So when unsaturated fatty acids are made by the body they're always cis, which makes me think the trans variety won't be metabolised very well in the body and therefore cause a greater increase in c... | [
"If I might hazard some educated guesses at mechanism (biochem PhD here), then I might guess that the trans compounds slip through the cracks. While fatty acids with a double bond in nature are cis, they would be easily excluded by shape from enzymes designed to handle only saturated fatty acids. Some of these enzy... |
[
"Why do I feel better after I cry?"
] | [
false
] | I've been all fucked up about things lately and I just had a good ole cry about things and I really feel like a different person. What does crying do to make me feel at peace? | [
"All I have to go on is ",
"Wikipedia",
" but what it has to say is definitely intriguing.",
"Tears produced during emotional crying have a chemical composition which differs from other types of tears. They contain significantly greater quantities of the hormones prolactin, adrenocorticotropic hormone, Leu-e... | [
"There is no way you would get IRB authorization for an experiment where one step is:",
"Now we make fragile people cry.\n"
] | [
"Unfortunately there doesn't seem to be much evidence to support the claim, which is odd since you can test cortisol levels fairly easily.",
"How would one go about setting up such an experiment? I mean, you'd have to induce situations that would make people cry, wouldn't you?"
] |
[
"Are there any speech impediments only found in specific languages?"
] | [
false
] | Or can they all appear in any language containing the "impeded" sounds? | [
"This is not really answer, but a clarifying comment regarding your question as your question, at least to me, is a bit vague.",
"Edit: Mods, feel free to delete if you do not find this adequate.",
"It's important to understand that speech impediments can vary in cause. It can be a physical defect in the speec... | [
"Thanks, your clarifcations got at the question I was really trying to ask. Would it be ",
" for a speech impediment to only affect one language or language family? E.g. A person replaces [s] with [θ] when speaking English, but not when speaking Japanese. My instinct is that it couldn't happen, but I'm wondering ... | [
"You may or may not have access to the full-text, but ",
"this article",
" on congenital amusia (tone-deafness) suggests that those who are tone deaf and speak tonal languages can produce contrasting tone phonemes just fine, but have marked impairments in their discrimination and perception of lexical tones. T... |
[
"With sunglasses on, one of my computer monitors is almost unaffected, only slightly darker, and the other one turns entirely black. What about monitors or sunglasses makes them react differently?"
] | [
false
] | null | [
"Most monitors have a polarization layer on the screen that helps to greatly reduce any glare on the monitor. The effect is that light emitted by the screen itself is also polarized in a certain direction. If you then pass this light through another polarizer, such as polarized sunglasses, then depending on the ori... | [
"Correction to ",
"/u/Rannasha",
" 's answer....",
"Most monitors have a polarization layer on the screen that helps to greatly reduce any glare on the monitor.",
"Most flatscreen monitors have ",
" polarization layers that are ",
". Glare reduction is not the purpose.",
"LCD monitors work by having ... | [
"More fun: If you put a second pair of polarized sunglasses between the first pair and the monitor when the monitor looks black, you can find a rotation for the second pair where some of the monitor's light is visible again."
] |
[
"How could viruses with high mutation rate like HIV maintain their functions? Isn't it like reshuffling pages in a book without changing its meaning?"
] | [
false
] | A genome of a virus is surely more complicated than an average book, and its mutation is like removing or reshuffling some of its pages. And somehow the entire book still makes sense (aka maintains its functions)? | [
"I would suggest that a mutation is more like changing a single letter on a page in a book. These mutations typically do not have positive impacts, most are deleterious, and more effective organisms (virus, bacteria, cells, etc.) out compete the now less-effective mutated organism. If the mutation is serious enough... | [
"The majority of HIV virions produced are not infectious. HIV's strategy relies, in part, on integration into the genome such that a single provirus (i.e. the DNA genome) can produce innumerable progeny. ",
"In short, you only need one successful infection event with HIV, theoretically, to get near limitless trie... | [
"To extend your book analogy, the better way to understand it is to imagine you have a stack of millions of books, and you occasionally randomly substitute one word in each book. In one the random substitution turns a 'hello' into a 'goodbye' and now the sentence no longer makes sense, so you throw that book out. I... |
[
"Does hair growth add weight?"
] | [
false
] | Okay say I shaved my head. Would I, as a whole, get heavier as my hair grew back? | [
"You would get heavier as you consumed food. Hair, in this analogy, can be seen like sweat. The only difference is that it's an excretion you retain, instead of one that evaporates. "
] | [
"No, because it's just moving mass around your body. Hair gets its mass from foods that you consume."
] | [
"Of course. All other things being equal, there is more of you than there was before, so you will weigh more. It's not that hair growth uses up another part of your body."
] |
[
"How does anything other than a head shot kill you instantly?"
] | [
false
] | So I was watching a crime show, and the coroner said the victim died instantly after being shot in the heart. Wouldn't the brain continue to function for a few minutes until it ran out of oxygen? | [
"Being shot in the heart would likely result in hypovolemic shock. ",
"I'm not of what exactly would happen to a heart when being shot, but lots of blood would be lost. This rapid loss of blood would cause hypovolemia, or a state of decreased blood volume. This would likely cause the victim to lose consciousness.... | [
"\"Died instantly\" really has two meanings, the literal and (what I'll call) the perceived. If something shreds your brain to pulp, it really is instantly. If you got hit on the head hard enough to lose consciousness, and then shortly there after a bleed stops brain function some people still call it instant. "
... | [
"I agree with Sunny. Literally, the only way to lose consciousness immediately would to have your brain pulverized instantaneously. We've all heard speculation about how long a person who has been beheaded stays conscious. In my mind, this is the ultimate trauma besides instantaneous brain injury, and even then the... |
[
"How much energy does it take a bird to flap its wings during flight? Is it equivalent to humans walking/running?"
] | [
false
] | Oh wow. Thanks for all the amazing answers and follow up questions. For science! | [
"It varies by the type of flight and the species of bird. Most flight is energetically expensive, at least on a calorie per second basis. ",
"Gliding is very efficient, especially with favorable thermals. Some birds can fly for hours without a single flap. This is roughly analogous to you standing on a bicycl... | [
"How does the energy expenditure of a hummingbird compare to a bee?"
] | [
"What seems like aimless flying around to you is probably serving a purpose for the bird. They have to fly around to forage for food, look for potential mates, look around their nesting area for predators/rivals, collect nesting supplies and that sort of thing."
] |
[
"How Rats and Mice developed symbiosis with humans?"
] | [
false
] | null | [
"Cats, dogs, pigeons, crows, etc. Anything living in cities basically. There are wild mice and rats that do not live in cities like field mice."
] | [
"Cats, dogs, etc. were domesticated by man. This is not what I was asking."
] | [
"What does it mean to domesticate? How different is it from pigeons, possums, skunks, seals, fish, bears etc. coming to places or living where they learn that food can be found?"
] |
[
"I turn my iPod on \"shuffle.\" Had I clicked the same button earlier, or ten seconds later, would the result have been any different?"
] | [
false
] | [deleted] | [
"Difficult to say, unless somebody knows the seed of the random function in the shuffle. It is quite common to use system time in milliseconds or similar as a seed for low security randomisation, so if that is the case in the source code of the ipod music player, then yes, it would be different. Most other sources ... | [
"Yup, even if we were to go to something more secure liking using a seed generated from noise on the CPU, we would still likely generate a different song choice."
] | [
"Think of the code saying:",
"play random\nrandom = number\nsong = number\nplay number\n",
"the programing just takes a random number generated the instant the code is run (so yes it will be different every time you ",
")"
] |
[
"Can levels of calcium in ancient bones tell us anything of interest?"
] | [
false
] | Or is there jut too much contamination etc to analyse the Ca levels? | [
"Calcium isn't radioactive, so it wouldn't be useful in determining age. Diet maybe?"
] | [
"Why would analyzing Ca be of any value? Ca is one of the major elements in bone, which is made largely of hydroxyapatite (Ca10(PO4)6(OH)2). Because of this, Ca would be less subject to contamination than many other elements."
] | [
"It's most useful for making deductions about diet. ",
"Here's",
" one case where calcium levels in the bones of Roman gladiators tell us that they actually took calcium supplements, in the form of small amounts of wood and bone ash, because their regular diet didn't contain enough calcium. It's not ",
" abou... |
[
"The real culprit of 90's violence was lead? Does this theory have any truth in it?"
] | [
false
] | [deleted] | [
"Lead is bad for neural development, like the parts of the brain that deal with impulse control."
] | [
"Boom: ",
"http://en.wikipedia.org/wiki/Lead_poisoning#Nervous_system"
] | [
" check the wiki."
] |
[
"Could a dog survive on the exact same diet as its owner? (no chocolate)"
] | [
false
] | null | [
"The phrase \"",
"eating your own dog food",
"\" is believed to have originated with the president of the Kal Kan pet food company. He claimed that their pet food was good enough to eat (by humans) and put his money where his mouth is by eating a can at a shareholders meeting."
] | [
"It was my impression that it was the theobromine in chocolate that was toxic to dogs. White chocolate should indeed then be very safe -- it's not really chocolate at all, and contains minimal theobromine. On the other hand dark chocolate should be incredibly dangerous, even more so than milk chocolate, which has... | [
"The main active ingredient in chocolate, especially dark chocolate is Theobromine. It is similar to caffeine and is what gives humans the 'kick' from chocolate you would usually get from coffee or pop.",
"That being said, theobromine is very toxic to dogs, as they are unable to metabolize it fast enough to over... |
[
"What determines where the poles are on a ball magnet? Or a bar magnet?"
] | [
false
] | On a bar magnet, one end is north and the other is south. What exactly determines which end is which? What about a sphere magnet? They would be on opposite sides obviously but what determines where the north and south are on something that doesn't have ends? Couldn't really find an answer from google but I probably don... | [
"Its defined by how it was magnetized, the direction of the field that was applied when making it. The internal magnetic domains align according to that.",
"There is no particular reason that a bar magnet has to have the poles at each end either. It would be perfectly feasible to make one with one long side nort... | [
"There is no particular reason that a bar magnet has to have the poles at each end either",
"Yes, there is! For an elongated shape, shape anisotropy (caused by the demagnetising field) favours magnetisation along the long axis."
] | [
"True, but you can still make one that has its poles along the long side, couldn't you? It just wouldn't be as strong as one with its poles on the short side"
] |
[
"AskScience, What is your take on \"Torus Vortex Mathematics\"? [video inside]"
] | [
false
] | [deleted] | [
"In short that sounds like a quite typical pile of crackpot nonsense to me. I don't actually see any real physics or math here. as far as pseudoscience goes, it's below average in the pseudo- ('appearance of') department. Looks and sounds more like a New Age book than actual physics or mathematics.",
"It's not ac... | [
"Apparently he's a student of ",
"this dude",
", and from a cursory reading, it looks like typical crackpot science.",
"Edit : holy timecube on a popsicle, its nonsensical. Also ",
"refer here",
" for some insight. This guy had better be trolling and I quote ",
".",
"TEDx is not the same as TED. Its o... | [
"So I watched one of his \"advance math\" videos on youtube. I feel like this is a perfect example of taking a little bit of knowledge/ seeing an underlying pattern and just going \"off the reservation\" with it. From what I saw he was working with what is known by real mathematicians as modular arithmetic. Its not... |
[
"How do scientists describe where something is in the universe?"
] | [
false
] | To locate a place on earth, we use Longitude and Latitude, and everything works because it's in 2 dimensions and the continents are not constantly moving. But in space, there are 3 dimensions and everything is constantly in motion. So how do scientists describe the coordinates of various stars or planets in the univers... | [
"There are two coordinates used to describe where something is in the sky: declination, which is how high the object is relative to the celestial equator (the ring of the sky above Earth's equator; Polaris has almost degrees declination), and right ascension, which it's how far \"East-West\" something is in the sky... | [
"This ^",
"I was also taught to use different fundamental planes (although this is something I rarely come across these days), so, if I remember correctly, you could locate celestial bodies using the Horizontal, Equatorial, Ecliptic, Galactic or Supergalactic coordinate system. ",
"So, for example, I believe He... | [
"Never knew there was a sort of equator for various galaxies! Awesome stuff to read about, thank you both for your answers!"
] |
[
"With antibiotic resistance becoming more prevalent, what are some possible effective antibacterial alternatives for the future?"
] | [
false
] | null | [
"In the body: immunotherapy, vaccination, GMO counter-pathogens.",
"Out of the body: UV sterilization, copper plating, protein denaturing chemicals.",
"I'm sure there are other things coming, but that's just what's off the top of my head."
] | [
"In my opinion the only way we will ever \"overcome\" resistance in bacteria (or viruses/fungi for that matter) will be using other organisms instead of drugs. My hope is that someday we will be able to use bacteriophages (viruses that specifically target bacteria) for this. Since the virus can evolve as quickly (o... | [
"I foresee the future of bacteria fighting beimg in bacteriophages. These are viruses \"programmed\" to attack specific bacteria. The interesting thing about these bacteriophages is that they can leave all the good bacteria untouched. If your interested a quick Google search can give you a plethora of information o... |
[
"Is it possible to temporarily shut down the corpus callosum (with an injected local neuroleptic or something) to create a transient split brain state?"
] | [
false
] | I'm very interested in the possibility there might be more than one "consciousness" in a brain. Like all questions regarding "consciousness", this is a hard subject to tackle. I'm familiar with the state of research with patients who have undergone corpus callosotomy. In these cases, the non-speaking hemisphere collect... | [
"The brain is divided into 2 hemispheres, that are connected by several fiber tracts, the largest of which is called the corpus callosum (CC). In people with certain types of epilepsy, we can surgically disconnect the two hemispheres by cutting/removing the CC (this can help reduce the frequency and severity of th... | [
"In theory, rTMS could be used to temporarily disrupt callosal activity, but it would be difficult to focus the pulse only on the CC without a craniotomy. As for using the Wada technique, the CC has vascular input from both the anterior and posterior cerebral arteries... it would be essentially impossible to pull ... | [
"Eh, I figured other people would benefit from it too."
] |
[
"Meteor? Space Junk? Radioactive debris and I'm going to die?"
] | [
false
] | So I heard a clunk on my roof and then this landed on the gravel path in front of me. Can't say it was hot but it certainly is like nothing I've seen before. All I really know is its dimensions, and its weight (5 grams). What is this? Oh, and it appears to be ferrous but according to my fridge magnets it's not that str... | [
"You should probably go over ",
"this site",
" before doing anything further. Most people don't find meteorites, but a rare few do."
] | [
"If your concerned about radioactivity, you could give your local university physics department a call. They should have a Geiger counter around and are likely interested in a potential meteorite. ",
"PS: I know on earth its exceedingly rare to find anything natural with dangerous levels of radiation. In space? I... | [
"Doesn't look like ",
"this one"
] |
[
"What was the average lifespan of pre-historic man?"
] | [
false
] | Or what is a reasonable estimate. How long did early Homo Sapiens live? How often did he die of natural causes, as opposed to surprise mountain lion? I'm doing some research and I realized I'm making some assumptions about the early lifespan of man that I have no basis for. | [
"Why are you people guessing? Stop guessing! Provide some sources!",
"First, we need to figure out what you mean by \"pre-historic\". You say early ",
", so I'm assuming you mean paleolithic/neolithic. The term \"prehistoric\" is a big one, and it includes things like pre-contact American Indians. This is ... | [
"That's what the \"mean adult age at death\" means."
] | [
"\"Mean adult age at death\" means the average age of death for an adult. Life expectancy is usually given at Ex0, which is the mean life expectancy for an infant. In the case of the Neolithic populations, the Ex0 was about 25. The average age at which the adults they studied died was 32.",
"Also, please provi... |
[
"Assuming the human eye has a resolution of 1 arcminute - why did HDTV ever take off?"
] | [
false
] | [deleted] | [
"I usually point out the chart that willbir mentioned.",
"I think your constraints are atypical, and maybe that's why you don't understand. If you can't do anything to decrease the 3m viewing distance, and if you simply don't have room for a bigger television, then all you can do is find your place on that chart ... | [
"I fail to see how this implies no real world benefit. I mean i've never seen anyone have their tv more than 10-12 feet away from whatever furniture they use to sit and watch tv, so according to this chart even 1440p would be a distinguishable improvement from lower res, let alone 1080p. And given the same screen s... | [
"No, you've got it exactly right. It's why the entry-level 4K TVs that are only 140cm (55 inches) are only really useful as computer monitors, since you have to sit so close to them to benefit over a traditional 1080p display.",
"Just one clarification -- the sizes that you give are the actually at the top of th... |
[
"What is the mechanism of Uncanny Valley?"
] | [
false
] | Have people before the advent of AI experienced this phenomenon? Are we likely to feel this way about our closest relatives-apes? | [
"Have people before the advent of AI experienced the Uncanny Valley? Absolutely. The Uncanny Valley isn't new by any means.",
"To elaborate, what we refer to as the Uncanny Valley is something like a scale of \"realism.\" Most often, in the sense of how human-like something is. It can be more broadly applied, but... | [
"Ah, “close but wrong” is exactly what describes my sentiments. Thanks for this phrase!"
] | [
"Here's an article that digs into it:\n",
"https://www.jneurosci.org/content/jneuro/39/33/6555.full.pdf"
] |
[
"In the way that gravity is based on mass, and electromagnetism is based on charge, are there analogous properties for the weak/strong nuclear forces?"
] | [
false
] | Gravity and electromagnetism seem quite similar in that they are forces based on the mass and charge, respectively, of the objects involved. Do the strong and weak nuclear forces have similar properties that the interactions are based around? | [
"The strong force property is ",
"color charge",
", of which there there are 3 types and three anti-types.",
"For the weak interaction there is ",
"weak isospin",
" and ",
"weak hypercharge",
", but these act a lot less straight forward, and also depend in part on the electric charge (or the electric ... | [
"I recently had to teach basic particle physics in a high school setting. Is there a simple explanation for color charge? I've read the wiki and I still don't understand:"
] | [
"Yes, and the rule that all free particles must be colorless “explains” why we see baryons (bound states of 3 quarks) and mesons (bound states of quark anti-quark pairs), but we don’t see individual free quarks, or bound states of 4 quarks, for example. ",
"Gluons, which are the bosons that mediate the strong for... |
[
"How to determine the age of a person medically? eg: to validate a guinness record for oldest person in the world as the written records can be forged"
] | [
false
] | null | [
"How to determine the age of a person medically?",
"You can't. Guiness goes by written records. People have been excluded from the book when they didn't have records. You print up your own birth certificate, but you can't print one up that's 120 years old and was registered by a government agency 120 years ago."
... | [
"Not sure if this is a procedure that can be done while the person is alive under medical grounds (I guess you can take a tooth from them?) but I think an accurate way is to radiocarbon date teeth. It's been done to archeological remains to estimate the age of the deceased individual. The principle relies on the ca... | [
"The NCBI article is claiming +/- 1.5 years for bomb radiation dating in your teeth as long as you’re born post mid-1940’s, 10 years for other carbon dating methods."
] |
[
"So human babies are woefully underdeveloped at birth compared to other mammals. How would, theoretically, a much longer pregnancy affect human development?"
] | [
false
] | So our pelvis is now made for walking on two legs and our craniums are large, explaining this is necessary. However, would this be possible, and what would the implications be? Would a longer pregnancy have any positive effects whatsoever? What would be the effect of the deprivation of sensory input? Any other implicat... | [
"I think the premise of the question kind of implies that things like this would be adjusted as well."
] | [
"Well ignore my panelist bar here, but baby horses can walk in a few seconds after birth; many animals can do at least something when born. But its true that its highly dependent on the niche the occupy. ",
"However, my Documentary-based knowledge is that we have underdeveloped babies on birth because our head si... | [
"Because it says ",
" and human babies can't climb right? Judging by the upvotes that's been a convincing thought, but sperm can swim. Are they more developed than human babies who can't? Of course it's a contradiction to even ask whether sperm are \"more developed\" than what they develop into, obviously they're... |
[
"In regards to sunscreen and its effectiveness over time. How is it \"used up\"?"
] | [
false
] | They say that you need to reapply sunscreen every two hours but is that duration dependent on how much the sun's photons reacts with the sunscreen on your skin or is it simply that the sunscreen loses its effectiveness the longer it is on your skin? | [
"Humans sweat and rub their skin. Over time the sun screen is either absorbed or rubs off.",
"Aside from that, it doesn’t fully block UV light; only enough so that the skin can repair any damage inflicted. Over time, the damage due to exposure increases past the point your skin can safely handle."
] | [
"What do you mean by absorbed?"
] | [
"See what I'm wondering is if we put the sweating and rubbing off aside, would we have to reapply?"
] |
[
"Does a saline IV dilute hormones your body produces during childbirth?"
] | [
false
] | I've been reading through the Bradley Method of childbirth with my wife and, while the exercises and relaxation techniques are great, there seems to be some bad pseudo-science in the final chapters. The BM (heh) says 2 things about IVs drips. One is the above, that a saline/glucose IV dilutes hormones your body natural... | [
"It would take a pretty significant amount of fluid to appreciably dilute hormones in the bloodstream. I don't have much experience with routine delivery of babies in the hospital setting, but I can't imagine that women in labor are generally given huge fluid boluses (especially since one of the primary pregnancy c... | [
"Here's ",
" study that seems to indicate that more fluids (250mL/hr vs 125mL/hr) led to 'easier' deliveries:",
"http://journals.lww.com/obgynsurvey/Abstract/2006/10000/Increased_Intravenous_Fluid_Intake_and_the_Course.5.aspx"
] | [
"As mentioned, no fathomable amount if an IV drip will dilute your blood that much.\nBut the second part of your question is slightly correct. Estrogen causes the uterus to release glucose, which is the fermented by Lactobacillus bacteria naturally found in the uterus. This fermentation process is does decrease the... |
[
"Why do I dream more vividly when stressed?"
] | [
false
] | null | [
"Are you sleeping the same number of hours? Are you waking more often during the night?",
"I ask this because many people have a lot of dreams that they simply don't remember, unless they awoke during the dream."
] | [
"I am sleeping the same number of hours. I don't think I am waking up more during the night, but the sleep is less restful. Perhaps I am waking up during the night but not remembering it in the morning. "
] | [
"Are they just regular dreams or are they nightmares?"
] |
[
"Are humans unique in their ability to consciously act against their best interests?"
] | [
false
] | In other words, I've never seen an animal knowingly commit suicide or eat something poisonous, or engage in hazardous acts with the intent to harm themselves. Sure animals get themselves trapped or hit by cars, but is there any case of an animal intentionally harming itself for the sake of harming itself? EDIT: The qu... | [
"I can't say for sure, since that falls outside my realm of experience (evolutionary dynamics) and starts to become a question for an animal behaviour specialist.",
"I suspect not though. Given the challenges we are having defining what consciousness and free will are in humans, I doubt anyone has done even minim... | [
"No, we're not, and understanding the evolutionary significance and implications of this type of behaviour (",
"altruism",
") is a major field of current research in evolutionary theory.",
"The classic example are prairie dogs, when the group is out of the warren if an individual spots a predator it will make... | [
"Intresting. I'm browsing from my phone now, so I think I'll wait to take a look. Thanks for the info!"
] |
[
"What would happen to a dead body if it was just dumped in space?"
] | [
false
] | null | [
"It depends on where it was dumped, ie close to the sun it would be damaged more than out around Pluto. It would definitely dry out though. Some of the liquid would freeze initially as the air pressure dropped. Some water would evaporate away. Anywhere inside the orbit of Earth (roughly) the body would dry out enti... | [
"Provided that it doesn't collide with an object and/or go spinning into someone's atmosphere first."
] | [
"What happens to a human body in vacuum//How determines the temperature of objects in space?"
] |
[
"What are the differences between waves?"
] | [
false
] | [deleted] | [
"Light waves and microwaves are the same, just at different wavelengths. They are both examples of electromagnetic waves.",
"Sound waves are just the motions of compressed air. A vibrating object will cause the air around it to compress and then decompress as it moves towards the air and then away.",
"We call t... | [
"First I just want to say, they are ",
" parabolas. They are sin (or cos) functions. Which do look like parabolas near the top or bottom of a wave but not quite the same.",
"The rate of change of a wave, is governed by that waves frequency or wavelength (they are linked, high frequency means shorter wavelength.... | [
"First I just want to say, they are ",
" parabolas. They are sin (or cos) functions. Which do look like parabolas near the top or bottom of a wave but not quite the same.",
"The rate of change of a wave, is governed by that waves frequency or wavelength (they are linked, high frequency means shorter wavelength.... |
[
"Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science"
] | [
false
] | Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical post? No question is too big or small for AAW. In this thread you can ask any science-related question! ... | [
"The body would be subject to the same laws of physics as anything else. Assuming an airtight seal, it would experience minor degradation as it would allow microorganisms present to decompose it for a time before death. A non-airtight seal allows particles to escape, and assuming all microorganisms present die, the... | [
"No, those are all obstacles we've already overcome with space probes. Biggest obstacle is just time.",
"Also I didn't realize your question was about sending a dead body out of the solar system lol",
"We've sent probes outside of the solar system already. Wouldn't be hard to send an inert coffin the same way."... | [
"The mathematical solutions are points, but the practically useful regions are huge. JWST and Gaia orbit the Earth/Sun L2 point at distances of a few hundred thousand kilometers. Compare this to the 1.5 million kilometers between Earth and L2."
] |
[
"As someone gets more obese, do their actual skin cells stretch or do they replicate fast enough to keep up with the increasing surface area?"
] | [
false
] | A follow up question would be: If the cells stretch more than they replicate, does this mean that there is a lower concentration of nerve endings? Would stretched skin around large fat deposits be less sensitive to touch? | [
"Their skin cells divide to increase surface area. Individual cells have limited elasticity and if they simply stretched to cover the increased fat tissue underneath, it would be like blowing up a balloon (e.g. getting thinner). In fact, more than just the skin cells help cover the area. Blood vessels, connective t... | [
"To add to this, they can only replicate so fast, so if you gain weight (fat cells, which grow more quickly) faster than your skin can keep up, you’ll get stretch marks, which are permanent weakenings in the connective tissue layer below the thin outer skin layer. ",
"Edit: I’d like to clarify that stretch marks ... | [
"You'd be amazed at what the human body can adapt to. There was once a guy in Scotland I want to say, he got his car stuck in the snow in some remote area, and was stranded. He basically hibernated in his car and lived for like a month without food just eating snow to stay barely hydrated.",
"Edit: ",
"Here's t... |
[
"Ketchup as a non-Newtonian Fluid ?"
] | [
false
] | How has it been proven that ketcup is a non-Newtonian fluid, and how does it rank against other fluids? Wherever i look about this they mention the ketchup effect, however that is an analogy and that in itself is not proof (analogy's can be missleading in that way). I was reasoning that if ketchup is a non-Newtonian fl... | [
"According to ",
"Viscosity functions data\nshowed that all ketchups under examination were non-Newtonian\nfluids, since the values for flow behaviour\nindices, n, were below 1, which was indicative of the\npseudoplastic (shear thinning) nature of tomato ketchups\n(Singh Gujral et al., 2002; Sahin & Ozdemir, 2004... | [
"I think there is a misunderstanding going on here as to what a Newtonian fluid actually is. A Newtonian fluid is simply any fluid that obeys Newton's law of viscosity. Simply put Newton's law of viscosity is that there is a proportional response between applied (shear) stress and the velocity profile of the fluid.... | [
"Because fluid dynamics are complicated. There is a lot to learn when dealing with the relatively simple Newtonian fluids. Frankly, not many physicists ever even specifically learn much about non-Newtonian fluids in a classroom because it's just not really a core component that most physicists need to know a lot ab... |
[
"Are there any bacteria or viruses which are resistant/immune to antibodies?"
] | [
false
] | I am aware that it is possible for bacteria to become resistant to antibiotics and for some viruses to gain resistance to anti-viral meds. But is it also possible for them to become resistant to antibodies produced by the immune system? | [
"Yes, and it's much more interesting than the obvious antigenic drift that we see with influenza viruses (and probably coronaviruses as well).",
"As background ",
" has an arsenal of ways to avoid the immune system; every virus today is the outcome of millions of generations of viruses that successfully avoided... | [
"Yes, it happens all the time. Antibodies bind specific locations on pathogens, if the pathogen slightly alters those locations the antibodies don’t bind as well. Now irl your body produces many antibodies against many epitopes (specific locations) on pathogens so they are still recognized, just not as well.",
"E... | [
"But is it also possible for them to become resistant to antibodies produced by the immune system?",
"You can go further, there are viruses that go beyond and actively use the antibodies your body produces to attack you further. It's called antibody dependant enhancement, or ADE. Dengue fever is one such example.... |
[
"What evidence lead to the comination of two of the universal forces, electromagnetism and weak force?"
] | [
false
] | From the previous force weak, electromagnetic, gravitational, and strong( now known as colorful force?) | [
"What evidence lead to the comination of two of the universal forces, electromagnetism and weak force?",
"Perhaps most primarily, the nonzero mass of the W and Z bosons.",
"After quantum electrodynamics proved to be a very successful theory, the same framework (quantum gauge field theory) was used to model the ... | [
"I have no quarrel with you",
"Sure -- sorry, I don't mean to start an argument, I'm just disagreeing. :)",
"I think that your original post is informative about the Higgs mechanism, but that it does not elucidate why people were interested in unifying the electromagnetic and the weak forces. And it's not that ... | [
"Hey, thanks for the post"
] |
[
"Is it possible for particles to briefly or temporarily exceed lightspeed?"
] | [
false
] | 1) I heard from a professor or TA once that particles have some nonzero probability of exceeding lightspeed, and that that probability decays very quickly outside of the particle's lightcone. Is this true? Is this possible? How does it work? 2) Second question. Suppose an electron is flying along, and then somewhere up... | [
"(I have to say I think it's funny that nobody seems to have identified yet what the questioner is talking about, even though ",
" do, and I'm in a branch of physics that makes almost no use of QFT whatsoever)",
"I'm pretty sure what your teacher in 1) is talking about is the Feynman propagator, which indeed is... | [
"Mathematically they are allowed to exceed the speed of light, but the physical implications are damning."
] | [
"I am sorry, RRC, but this is the correct answer to question 1. Peskin and Schroeder chapter 2, discussions on the causality of the Feynman propagator. ",
"Edit: some of the text of the chapter, which contains an important nuance:",
"\"So again we find that outside the light-cone, the propagation amplitude is ... |
[
"What effect does the seawater brought inland by a tsunami have on local plants? Does it make the land infertile for a while?"
] | [
false
] | null | [
"In Holland we don’t have tsunami’s, but the results of salt water floods have been studied pretty well. For instance, after the 1953 north sea flood.",
"For the Dutch soil, all salt from flooding is washed away within 1-4 years. This depends on sveral factors, such as duration of flood, dept of the groundwater l... | [
"It seems likely that tsunamis impact local plants / soil through the addition of clay and silt with a high salt content. Land is inundated by a tsunami for a relatively short period of time and the salt is usually washed away by precipitation anyway meaning that the saturation of soil by saltwater is not the leadi... | [
"Evaporation in the Netherlands is probably not a big issue (We’re further north than Newfoundland).",
"But in Holland much of our land is below sealevel, so if a flood happens the land is inundated for weeks before it is pumped away. ",
"However, we’re basically living in a swamp, so all the ground is already ... |
[
"How does a computer determine if a given number is larger than another number?"
] | [
false
] | null | [
"Typically, a computer will represent binary numbers in a slightly more complicated way than you may have been taught in school.",
"Positive binary numbers are simple enough. They work like regular numbers, except you only use ones and zeros, i.e. counting up from zero is 0 -> 1 -> 10 -> 11 -> 100 -> 101 etc.",
... | [
"Here is an example of how 2 numbers in binary can be added with the use of logic gates: ",
"https://cdn.instructables.com/FP1/ZI2I/GHX77248/FP1ZI2IGHX77248.LARGE.jpg",
"there you have one number (A) that can be 1 or 0, and another number (B) that can be 1 or 0, and the sum can be 00=0, or 01=1, or 10=2.",
"T... | [
"Unless you want to vary the clock cycle speed depending on the instruction",
"This is exactly what I'm doing - there is no global clock signal. This is how most redstone computers work, because the game itself provides a predictable clock in the form of every component having a known delay. Redstone is essential... |
[
"AskScience: What are you best science brain teasers?"
] | [
false
] | I'll start with what should be a well known thought experiment: Can a airplane on a treadmill take off? (Feel free to give an answer!) Who else has some good teasers? Ever fooled your supervisor? Ever been fooled by a really good one? Let's hear them! | [
"Your pee is already warm. Urinating will remove the mass of body-temperature pee and hence your total energy goes down, but you were in thermal equilibrium already (give or take)."
] | [
"Here's one that got me in back in high school. It's actually a math brain teaser. ",
"x",
" = x*x",
"x*x = x plus itself x times = x+x+x+x+...x (x times)",
"d/dx [x+x+x+x+...x (x times)] = [1+1+1+1...+1 (x times)] = x",
"BUT d/dx (x",
" = 2*x",
"2*x = x ??!?!?!?",
"The answer is actually extremely ... | [
"right but you are using energy to keep it warm."
] |
[
"If you move a wild bug far from its home but the same environment will it go back home or make a new life there?"
] | [
false
] | Like if you took a grasshopper from one side of a lake to the other, one mile away, could it make the trek home? Would it stay there and find a new cluster of grasshoppers like it? Would it starve and die? | [
"It really depends on the insect.",
"Many insects, I believe including grasshoppers, typically do not have one nest or other type of \"home\" they can return to. Most insects also do not rely on being part of one society or group. They live where they happen to be at the moment, and if they can't find what they n... | [
"IIRC bees attack other bees who don’t smell like the rest of the hive. IIRC beekeepers who want to introduce a new queen to a hive protect her with a small cage with a wax/honey plug. By the time she’s eaten through the wax plug she smells like the rest of the hive and is accepted by the worker bees."
] | [
"If they could not locate original home , could they become part of another colony? "
] |
[
"Why does the north get more snow than the south?"
] | [
false
] | From that image it really seems like there is more snow in the northern hemisphere. Why is that? | [
"Check this out:",
"(crappy but does the trick) ",
"map with tropics delineated",
"Southern hemisphere has very little land outside of the tropics, besides Antarctica. I didn't realize how lopsided the land distribution was. "
] | [
"Somewhat related tangent: Another indicator that the land distribution is lopsided is how the atmospheric CO2 concentration varies based on seasons. When the northern hemisphere is in summer the huge increase in photosynthesis decreases CO2. As I understand, most of that variation comes from forests in Asia; Sib... | [
"You do notice the biggish chunk of snow in the south, called the Antarctic?",
"I think the rest can be explained by the lack of large land masses around 40 latitude, and maybe the sea currents are distributed differently."
] |
[
"Why are there multiple stop codons (UAA, UGA, UAG) but only one start codon (AUG)?"
] | [
false
] | null | [
"There's a scientific paper on it: ",
"https://www.sciencedirect.com/science/article/pii/S0022519312001580?via%3Dihub",
"Its an evolutionary advantage to reduce useless translation and save energy. Here's the short summary: ",
"► We assume that the synchronization shift of length 3 in DNA or RNA is violated. ... | [
"There ",
"actually are other start codons",
"; they're just very uncommon in eukaryotes (everything other than bacteria and archaea). They're slightly more common in RNA than DNA, and they are a lot more common in mitochondrial DNA, which makes sense because they are a lot more common in prokaryokes such as ba... | [
"I can speculate that it's for the same reason: frame shifts will be less likely to initiate inappropriate transcription, thereby reducing the number of improper proteins."
] |
[
"Do the Voyager spacecraft experience time dilation and has it been recorded?"
] | [
false
] | Seems to me that since the Voyager spacecraft are the fastest vehicles ever built by mankind, they would be experiencing the most profound time dilation ever recorded by humans. So, has the time dilation that they are undoubtedly experiencing been recorded? | [
"I wouldn't say it's negligible. GPS satellites orbiting the Earth experience time dilation and have to synchronize their clocks with those on the ground to provide accurate readings."
] | [
"Exactly. For voyager 1, .05 seconds per year would translate into 28,050 meters difference in it's position over its 33 year life so far. Imagine trying to send a laser signal and being off by more than 28km."
] | [
"Voyager I is moving at 17000 m/s, which results in a negligible amount of time dilation. You're looking at a difference of ~.05 seconds per year in length of time experienced."
] |
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