title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"about the brains from futurama.."
] | [
false
] | So i was watching Futurama, the episode with the floating brains to be exact. sorry if this is a stupid question, but would it be possible for a species to actually evolve beyond the need for eating/using the bathroom?? | [
"you mean like a plant? although they still \"eat\" and \"use the bathroom\". Otherwise, i'd say no. The source of energy must come from somewhere, whether it be a chemotroph or phototroph. "
] | [
"Any species will need to get energy somehow to move, and get mass somehow to grow, and expel entropy in some way. ",
"Whether or not you define the more esoteric forms of these actions (for instance, getting energy from sunlight and expelling waste energy as heat) as 'eating' and 'going to the bathroom' is a se... | [
"One could define life as an entity capable of manipulating information. Storing, generating, and deleting information in a complex or simple way. No matter how you do this, the second law of thermodynamics says you'll require energy (See ",
"wikipedia",
").",
"So any species would need to intake energy in so... |
[
"Why does the event of two black-holes merging send large gravitational \"ripples\" across spacetime?"
] | [
false
] | I know that one of these events was used to confirm the existence of gravity waves, but do the two BH's actual merging emit waves that are stronger than are emitted in the aftermath of the event or is the "ripple" actually just the detectable start-point for the new SMBH's warping of space? What puzzles me is that blac... | [
"The gravitational waves are not produces by the merger itself. Any time when one body orbits another, it emits gravitational waves. In the case of regular planets and stars, the gravitational waves are negligible, because the orbital speed is too slow. But when the black holes orbits each other, their mutual attra... | [
"Don't they also emit for a brief instance as the merged black hole reaches its final state? i.e. the \"ringdown\"?"
] | [
"Gravitation waves of this type are predicted by general relativity, which has existed for over 100 years."
] |
[
"Why does putting scalding water on a rash feel good?"
] | [
false
] | I've found that cranking up the temp in a shower to the point my healthy skin feels pain but something like a poison ivy rash under the same water is euphoric, what is going on? | [
"The ",
"neural mechanisms behind itch-processing",
" are surprisingly complex, but to me the key word you're using is \"euphoric.\" That means we're not just talking about GABA or norepinephrine or 5-HT or dopamine suppressing your itch signals. \"Euphoric\" to me means we're dealing with endorphins. ",
"One... | [
"Rubbing the rash (or bug bit, or whatever) with a cotton ball is also very effective at stimulating the feeling of relief that comes from scratching without wearing or tearing the skin. I didn't believe it was so effective until I tried it."
] | [
"Rubbing the rash (or bug bit, or whatever) with a cotton ball is also very effective at stimulating the feeling of relief that comes from scratching without wearing or tearing the skin. I didn't believe it was so effective until I tried it."
] |
[
"Are we past peak fish/seafood?"
] | [
false
] | With reports of dwindling fish stocks, especially cod in my native Quebec. My question is, are we past peak seafood? Are we really going to run out of seafood and fish in the coming decades? | [
"My question is, are we past peak seafood? Are we really going to run out of seafood and fish in the coming decades?",
"Fish are renewable resource so long as we don't take more then they be can replenish - in the same way trees are renewable resource so long as we plant new ones once we chop the old ones down. C... | [
"This is a really excellent summary! (Primatologists apparently know a lot about fish...?) I was about to add that some countries, such as Iceland, or individual fisheries, such as the salmon fishery in Alaska, use market-based mechanisms to prevent overfishing that have been generally effective. They rely on ITQ's... | [
"This is a biased summary",
"I respectfully disagree... I did talk about the good and the bad - fishing, fishing practices, the science and opinions regarding this issue are very complex. It is my opinion that some regulatory bodies and other institutions are not taking this problem seriously enough. For me the s... |
[
"Do Sociopaths Have Empathetic Yawns?"
] | [
false
] | [deleted] | [
"Empathy can be broken down to a cognitive and affective component which are processed by two largely independent neural networks. Deficits for sociopaths typically arise in affective empathy; 'feeling' the associated emotion for the situation. Yawn contagion is theorized to be one of the simplest forms of cognitiv... | [
"Does this mean that, theoretically, a psycho/socio-path* would have the physical reaction (the yawn), but would not have any of the associated emotions or thoughts a baseline normal person would have. i.e. They experience a group yawn differently than a non-psychopath?",
"*Classes I took in the past took great p... | [
"http://www.reddit.com/r/askscience/comments/2etrsi/do_sociopaths_yawn_after_others/ck3jm9b",
"Previously asked, but the answer still leaves your question open. The best info I could find is that there has not been enough study into this area.",
"What we do know is that children under 4 or 5 and persons with a... |
[
"What is the science behind SimplyNoise making me productive."
] | [
false
] | null | [
"You get less distracted by your surroundings because it basically drowns out all the sound around you. (you probably noticed that you scare quite easily if some sound does come trough)",
"So it makes your surrounding more calm and serene, and if you are calm you work better. "
] | [
"Thats because if you cancel all sound, your ears become extra sensitive and start listening for sound. (this might be distracting on itself, as its unnatural) \nWhite noise however, \"blocks\" your hearing, like you'd be standing near a waterfall. So your ears stop looking for the sound."
] | [
"Thats because if you cancel all sound, your ears become extra sensitive and start listening for sound. (this might be distracting on itself, as its unnatural) \nWhite noise however, \"blocks\" your hearing, like you'd be standing near a waterfall. So your ears stop looking for the sound."
] |
[
"Space probe/rover plutonium question"
] | [
false
] | [deleted] | [
"The plutonium is contained in a RTG. This is relatively common on satellites. Launch failures have happened in the past, and it is no big deal. ",
"Wikipedia has a description of a few mishaps. ",
"http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Safety"
] | [
"Right, RTGs are built to be relatively safe. This is very different from a full-blown nuclear reactor in space, which can have much more serious consequences if unintended de-orbit occurs. Check out the ",
"Kosmos 954 incident",
" for an example of this."
] | [
"I'm no expert, but the ",
"RTGs",
" contain that plutonium in the form of metal pellets. If the rocket blew up on the launch pad(or high above it) there would be no extreme force to melt or otherwise vaporize the pellets. Retrieval would probably be trivial."
] |
[
"If leaving food uncovered in the fridge unhealthy (growth of bacteria, etc.), then why do a lot of drink pitchers have tops that leave drinks uncovered? Are drinks different than food when it comes to bacteria growth?"
] | [
false
] | [deleted] | [
"Not unless the alcohol content is 80 proof or more - way higher than you would want keep in an pitcher. Fire hazard. Also, not what most people would want to drink.",
"Leaving uncovered in the fridge will no cause it to spoil due to bacteria growth so much as it will cause it to spoil due to (a) dehydrating in t... | [
"Pitchers with uncovered tops are not meant for long term fridge storage. They are meant for serving and short term storage at the table, and don't need to be covered any more than plates do. Pitchers meant for use in the fridge have covers, usually the rotating sort that allows a piece to be opened or closed.",
... | [
"Water or juice should always be covered. In case of alcoholic beverages, the alcohol content will prevent bacterial growth."
] |
[
"How do particular bacteria, such as E. Coli, get into our small intestines?"
] | [
false
] | It seems mammals have a symbiotic relationship with specific bacterium (i.e. ruminants need cellulase-producing bacteria to digest cellulose), and since it's not like our genomes code for the bacteria, so how do these specific fauna get there in the first place? | [
"We eat them. The majority of bacteria don't make it through the stomach, but we've all had dodgy bowel movements to show that some obviously make them.",
"We promote tolerance at the intestinal mucosa through peripheral tolerance. This is to prevent continual inflammation which would eventually lead to tissue da... | [
"Contrary to popular belief, E. coli only makes up a very small percent of gut microbiome in healthy individuals. It's mostly Bacteroidetes and Firmicutes. A high abundance of Proteobacteria (e.g. E. coli) is an indicator of an unhealthy GI. "
] | [
"Contrary to popular belief, E. coli only makes up a very small percent of gut microbiome in healthy individuals. It's mostly Bacteroidetes and Firmicutes. A high abundance of Proteobacteria (e.g. E. coli) is an indicator of an unhealthy GI. "
] |
[
"Why can we barely remember events that happen when our emotions are at shock?"
] | [
false
] | Why is it that we barely remember things that are happening while we're in shock? I've had really unbelievable experiences that just happened suddenly out of no where and I was wondering what exactly causes it to all be a blur. | [
"Also I'd like to add to a question that I seem to remember the general \"feel\" or vague emotions that I experienced from that event, but not the specifics of it."
] | [
"If I can barge in on the question, I'd like to ask one of my own along these lines.",
"In my free time I'm a volunteer firefighter. As a result I've seen a lot of deaths and injuries. One thing that has always struck me as odd is that I can remember all these events, but I can't remember a single face, particula... | [
"I am not a neuroscientist, but I've read that brain has a special \"region of brain\" or \"way of recognizing faces\", because we can recognize faces of people, but when asked to \"please describe exactly their face by memory\" , it's hard, because we don't just casually remember how big nose, how far apart are th... |
[
"How is it possible that 200 unique species go extinct every day without much notice or change in our lives?"
] | [
false
] | [deleted] | [
"There are a ",
" of species. It's estimated we still don't know ~87% of land based species and ~91% of ocean species.",
"Considering there are ~8.7 million estimated total, 200 a day is easily unnoticed.",
"Also, the most important species to our ecosystems, that is, the ones we would notice missing, are num... | [
"I will get downvoted to oblivion",
"With all due respect, you should be. Remember that I'm not disagreeing with your views here, just your comment structure.",
"The Guardian and, in particular the UN, are significantly under the sway of 'big environment' and tend to promote the most hysterical, angst inducing... | [
"I will get downvoted to oblivion, but you really have to be careful with 'facts' such as these. The Guardian and, in particular the UN, are significantly under the sway of 'big environment' and tend to promote the most hysterical, angst inducing view of the present. ",
"In terms of species extinction, we would h... |
[
"Can Black Holes swallow or absorb one another? A 2nd grader asked me this and I didn't have an answer. (Astronomy question)"
] | [
false
] | As the title suggests, I was talking about stars and the like to my 2nd graders and briefly mentioned black holes. One student asked if they could "eat" each other. I wasn't sure how to answer. | [
"Yes, black holes can (and we very strongly suspect DO) merge. When this happens, they should spiral in together by emitting gravitational waves, which are ripples in spacetime that travel at the speed of light. These ripples distort space as they pass by, and some experiments such as ",
"LIGO",
" are trying to... | [
"Thank you."
] | [
"Funnily enough, I was at a seminar today involving LIGO and heard the same story, plus some. The Washington one can detect big waves on the coast even! My favorite part was that in Louisiana they had.... Problems, with people shooting the lines! People would just take pot shots at the lines and they facility was o... |
[
"Does human movement on board the ISS affect its orbit at all?"
] | [
false
] | [deleted] | [
"It doesn't affect its orbit. These are internal forces so the system will keep moving with the same momentum regardless of what happens inside.",
"If a human pushes the wall or pulls the handles to move then it may temporarily cause the station to slow down a little bit (ok, a ",
" little bit considering that ... | [
"ISS weights 450000 kg, adult human weights around 70 kg",
"So a human weights 0.01 % of the total mass of ISS, unlikely to make any difference on the position of the center of gravity.",
"I would guess that they spend more time correcting altitude, rotation and position due to drag (there is some atmosphere le... | [
"No, not on the magnitude that would be significant. The center of mass does not change once the shuttle has docked regardless of where the astronaughs move in the space station. If they move away from earth there is an equal and opposite reaction of the mass of the space station so the center of mass does not chan... |
[
"From NoFap - What happens to sperm and semen if you stop ejaculating?"
] | [
false
] | null | [
"Aside from the possible overflow of sperm production, I'm curious as to what other physiological changes occur within the body from the lack of fapping."
] | [
"Production of sperm will go down because the testes don't receive as many signals that they have to, but it will never full on stop. Sperm dies over a short period of time, so if it didn't continue, then you would become sterile.",
"If the overall amount of semen starts to exceed the amount that your testes can ... | [
"Age 33 here, and all it took for me recently was 7 NoFap days and holding a lady's hand for a couple of hours."
] |
[
"Why dont astronauts use cameras and screens instead of windows?"
] | [
false
] | null | [
"Insulation is not that big of a problem on the space station. Since the only way you can lose energy to space is through radiation, ",
"cooling off from the sun's blazing influence, in addition to all the heat-producing equipment on the station, is actually a bigger issue",
". This is achieved through heat exc... | [
"Yeah I read that as well, I understand that keeping in heat is not a problem, but they still have to design around that, why not make it simple and use cameras?. Also that would increase the viewable and monitorable areas on the station."
] | [
"From the same article above: \"astronauts need them for ergonomics and also for their research\". The mental benefit of seeing the outside world through windows are huge."
] |
[
"How deep in the earth was freshly spewed volcanic rock a day before it reaches the surface?"
] | [
false
] | I'm just wondering if geologists have an idea about whether magma comes from way deep or is just the stuff molten near the surface. | [
"That entirely depends on the nature of the eruption or flow. Most magma is formed 50-100km below the surface of the Earth's crust and rises into magma chambers due to lower density relative to surrounding geology. Magma chambers are usually 1-10km below the surface. as pressure builds, magma in the chambers can be... | [
"So I take it those neat little graphics on BBC specials with lava streaming up from the very core of our planet are bogus."
] | [
"Well technically it's true. The magma and molten earth cycle, sinking when they are hard, rising when it is liquid."
] |
[
"Is it possible for an iron core of a star to remain intact after \"star death?\""
] | [
false
] | It's common knowledge that at the core of large stars lies iron that has been made by the star. But is it possible after star death for the core not to collapse leaving open the possibility of gigantic balls of iron flying through space? | [
"Without any nuclear fusion to create an outward pressure, gravitational collapse will dominate, crushing the protons and electrons in the star together into neutrons. Now, in some cases the Pauli exclusion principle will create a type of pressure that can counteract the gravitational collapse, and you'll be left w... | [
"If all the particles already occupy the lowest energy levels in degenerate matter, how do you get further collapse? Why don't you run into a wall of infinite pressure at that point?"
] | [
"but if the star is sufficiently massive - and only the most massive stars fuse much iron - its gravity will overcome even that, and nothing is left to stop the descent to a black hole",
"Then how can we have all this iron around when only star that can produce it eventually became black hole?"
] |
[
"Why don't people ever forget how to ride a bike?"
] | [
false
] | on top of that why do people learn how to do so so quickly. It seems as though it may take a while to get there but there's an instance where a person can just ride a bike. it seems like the second someone can ride a bike they're an expert and stay at the same relative level of proficiency forever. It's almost impossib... | [
"I think it's a matter of acquiring the motor skills. Because motor skills are something you never forget. Your brain doesn't let you. If you're bedridden for a year you can still get up and walk (discounting the muscle decrease). You never forget how to throw or swim or do cartwheels after learning. Whether your i... | [
"It's almost impossible to distinguish a person who has been riding for two months from on with two decades of experience if they're just riding normally?",
"As someone who has raced and ridden an average of 10,000 kilometers per year over the past 20 years, I must disagree with this. Take anything you know very... | [
"I don't know if I can agree with the throwing because lots of people can get rusty at, throwing a football for example, myself included."
] |
[
"How fast would a room-temperatured bullet have to move for it to be true that 95% of the atoms were actually moving in the direction of the bullet at any given instant?"
] | [
false
] | As I understand it, heat is basically just jiggling atoms with no uniform direction. So a moving object should then have a fraction of its atoms moving the other direction, "relative to the ground". More generally one could ask, what is the relationship between the percentage of atoms moving in the direction of the bul... | [
"Since the bullet is a solid, any movement in a given direction will cause all atoms in it to move in the same direction. Theoretically, if you move a gas or liquid in a given direction, there will be a brief moment when what you are describing would be happening, but we're talking on the scale nanoseconds, at best... | [
"The speed of the bullet relative to the air/table/gun/ground won't have an impact on the motion of the lead atoms that make up the bullet, relative to each other. Thus, the number of atoms moving in ",
" the direction the bullet is travelling should be independent of the bullet's velocity.",
"If instead we are... | [
"So there is not any wiggle room what so ever for the atoms to actually move the other way for just a tiny tiny bit of time? If so, could this movement be just rapid enough that it for an instant goes against the movement of the bullet, while maintaining it's place in the solid?"
] |
[
"What do people living on space stations actually do all day?"
] | [
false
] | null | [
"They perform constant maintenance related to the station and conduct experiments on everything from the effects of zero gravity on the human body to radiation effects on cell growth. \nThis is this week's highlights",
"https://www.nasa.gov/mission_pages/station/research/news/wklysumm_week_of_08jan22.html"
] | [
"They probably also exercise a lot and I bet they do tons of data entry."
] | [
"They are working all day, and if by \"data entry\" you mean data collection for their daily jobs, then you would me partially right. They are busy all day every day with experiments and daily duties. There is actually very little down time where they do what they want."
] |
[
"Scientists: What theory or interesting fact from your field absolutely blew your mind when you originally learned/understood it?"
] | [
false
] | null | [
"There's a shrimp that shoots bubbles from its claw, and the bubble collapses and kills things with the ensuing shockwave."
] | [
"Wagner wrote music history. He's the guy who came up with the linear concept of music history, with Bach progressing smoothly to handel, to Haydn, to mozart, to Beethoven... And where do you think that lineage culminated? In the great works of Wagner, your humble textbook author! He basically wrote himself into hi... | [
"Would you say it's bubble gun is super-effective?"
] |
[
"How does poultry meat spoil/decompose differently than red meat? Isn't decomposing among all meats the same?"
] | [
false
] | null | [
"Yay, I can answer this. ",
"Different meats have different fat, water, and amino acid ratios. Fish is a great example since it has a high nitrogen content and low fat content which promotes Shewanella putrefaciens and Pseudomonas spp to become the dominant microbe. ",
"The animals also have different dominant ... | [
"Decomposition is mostly a matter of which microorganisms are best able to thrive in the medium. The major differences between, e.g., beef, pork, and poultry will be in the ratios of fat and protein, connective tissue, etc., but also in what organisms are already present within the meat, giving them a huge advanta... | [
"Don't lactic acid bacteria play a role in aged beef, i.e. where you deliberately allow it to \"decompose\" for some time in order to get better steak?"
] |
[
"Could a gas giant have an atmosphere? Where would the border be between \"planet\" and \"atmosphere\"?"
] | [
false
] | null | [
"Gas giants have very thick atmospheres, that is what the gas is. They are often said to lack solid surfaces, so the distinction between sky and ground may be less clearly defined than it is on our planet, though they may have a solid core."
] | [
"the transition is expected to be much more smooth than we would see on a terrestrial planet, with the gas increasing in density and pressure until it exists in a less defined fluid/gaseous state, below which may exist a molten/semi-molten core. ",
"For example: ",
"http://en.wikipedia.org/wiki/Jupiter#Internal... | [
"For some values of \"never\". There are no physical laws (as far as I know) that prevent us from ever constructing instruments which could penetrate the clouds."
] |
[
"Are memory-B cells passed from mother-child?"
] | [
false
] | The antigen remembering cells of the body, are they passed from mother to child? Or will a child develop all of their own new immunities, or only some? How does it work? | [
"No.",
"It's generally not a good idea for maternal cells to be present in the child for the same reason that it is not good for any other person's cells to be in the child: they are foreign cells and will be treated by the child's body as such. Granted, memory B cells wouldn't be as dangerous to the child as na... | [
"Follow up questions:",
"Does a baby have effectively zero adaptive immunity at the time of birth?",
"Are there any potential for a pathogenic bacteria or virus to enter the uterus or birthing canal?",
"Thanks! Great answer."
] | [
"There are a few diseases capable of being transmitted during birthing. These are generally sexually transmitted ones, seeing as the birth canal is host to said diseases. Certain diseases can also affect the embryonic fluid in the uterus, such as gonorrhea."
] |
[
"How does helium actually increase the pitch of your voice?"
] | [
false
] | null | [
"A lot of people believe that helium itself changes the pitch of your voice. This is actually incorrect. Your vocal cords are still vibrating at the same frequency, and since helium is less dense than air, sound travels faster. This accounts for the higher pitch. "
] | [
"Thanks for the clarification!!"
] | [
"Thanks for the clarification!!"
] |
[
"Why is silicon doped with phosphorous in solar cells? Why not another material?"
] | [
false
] | null | [
"Silicon-based solar cells can be doped with a number of materials; phosphorus is only one option. Typically, you'll have two dopants, one p-type (fewer electron/s) and one n-type (extra electron/s). These are usually from Groups III and V, or sometimes II and VI - for example, gallium and arsenic, boron and phos... | [
"If you are referring to the defect states themselves, yes they are often in the gap or very near the edge which could cause some narrowing. The are other effects, such as band gap renormalization (related effect, but doesn't seem to be well characterized as far as its origins in the literature), that occur when th... | [
"I disagree, at low dopant concentrations it doesn't change the band gap, in any detectable way at least. Sure, you have some states inside the gap, but the density of states in these donor bands is orders of magnitude smaller than the density of states in the conduction band. When you plot the density of states ag... |
[
"If you jumped into a river of lava, would die instantly, or would you suffer for a little?"
] | [
false
] | Me and my friends got into a big discussion about this, and both sides had good arguments, but no solid conclusion. Any help would be appreciated. I need to put this argument to bed, even if I'm wrong. Edit: Front page! Holy fuck!! You guys are really awesome. I got some great answers overnight, and appreciate every... | [
"I think you made a mistake with the pain part. Lava would instantly seer your nerves. You would feel nothing. The worst part is 1-4 feet proximity to the lava. Provided that you throw yourself at a large patch, the proximity to the intense heat would scorch your flesh and your nerves ",
" sense that and make you... | [
"Lava is ~100,000 times the viscosity of water. (",
"http://en.wikipedia.org/wiki/Lava",
")",
"Hence, if you jumped into a river of lava, you would not sink quickly. So from a strictly 'will you die immediately' sense, the answer is no. Your breath will sear you lungs. Your skin and other exposed membranes wi... | [
"It's not just the viscosity, but the density also. Lava is liquid rock, it's much more dense than a human."
] |
[
"Does anything happen to compounds when their electrons hop positions?"
] | [
false
] | For instance, when photons of light force electrons to switch to a different orbit. I was learning about transparency and this question came up. Thanks in advance! | [
"Yes, such a change in electronic structure can destroy (usually) or create (sometimes) chemical bonds. This is the basis of the whole field of Photochemistry. "
] | [
"All kinds of important things happen when electrons move around to different orbitals! Bonds are made and broken. Holes and electrons are generated in semiconductors: this is the mechanism of energy harvesting in a solar cell, and from the same we enjoy the output of an LED. It is also happening on the surface ... | [
"Within the Born-Oppenheimer approximation, every molecule evolves in time as though it were a particle",
" rolling around on a curved surface, namely its ",
"potential energy surface",
". Each dimension of this surface represents some change in the molecular geometry. Electronic excitation shifts the molecul... |
[
"Will a sudden lack of noise wake you up?"
] | [
false
] | Just like a sudden noise will tend to wake people up (like turning the TV on or an alarm), if you fall asleep with a noise and it is suddenly cut off, will you wake up? | [
"It really depends on what stage of sleep you are in when the noise stops. N3 (Slow Wave Sleep) is the hardest to arouse from. Also, at the end of every sleep cycle, there is a short awakening which you usually don't remember. During that awakening people usually just look around and fluff their pillow, but if s... | [
"Downvoting someone who prefaces their response with laymen goes against the spirit of this subreddit.",
"Anecdotal evidence is sometimes all there is to go on until a rigorous scientific study has been conducted. In fact it is the exact thing that brings about a formal study."
] | [
"there is a short awakening which you usually don't remember. ",
"Is there a technical name for this, I'm trying to find a Youtube clip of this."
] |
[
"Bar bet: Momentum versus gravity"
] | [
false
] | Imagine a person on a skateboard falling from a large height. Person A is moving forward very slowly before the fall. Person B is moving forward very quickly before the fall. Do they hit the ground with the same force? Assuming they both stay on their skateboards, will the impact to their body be different? Does the an... | [
"A shoulder roll makes a fall hurt less because you're spreading out both the area of impact and the time of impact. Instead of hitting all at once and stopping, you continue your motion to change your ",
"impulse",
". The fact that it's horizontal and not vertical motion is just a result of the fact that there... | [
"You can consider their vertical and horizontal momentum separately. Their vertical momentum is identical then, while one has a non-zero horizontal momentum. So their bodies will experience the same force upwards when they hit the ground (e.g. shattering their legs). But the one with a non-zero horizontal momentum ... | [
"That's what I thought too, but do you have any credentials I can use to avoid this being a straightforward layman vote?"
] |
[
"Why was the universe born with a cosmic imperfection?"
] | [
false
] | Dear , I was watching today. Good show, but the part that left me with more questions (as answering questions in science usually does) was the part where it says the universe was born with a slight imperfection out of the big bang that allowed gravity to give rise to the celestial structures such as galaxies, solar sys... | [
"So you have a dynamical model that (1) describes the process of universe formation, and (2) exhibits chaotic behavior? Or, at the very least, that predicts the dimensionality of the relevant phase space and demonstrates the relative volumes of totally homogeneous universes, nearly homogeneous universes (like our o... | [
"So you have a dynamical model that (1) describes the process of universe formation, and (2) exhibits chaotic behavior? Or, at the very least, that predicts the dimensionality of the relevant phase space and demonstrates the relative volumes of totally homogeneous universes, nearly homogeneous universes (like our o... | [
"A totally perfect, uniform Universe is far more unlikely than an imperfect one. In fact, a perfect Universe is pretty much impossible, compared to the misshapen kind we live in.",
"I don't think we know nearly enough (read anything at all) about the dynamics of universe formation to make a statement like this."
... |
[
"Is it possible that we could discover some place deeper than Challenger's Deep?"
] | [
false
] | null | [
"The ocean floor has been mapped out completely at low resolution- you can ",
"view it on Google Earth",
". It's a relatively shallow slope down to the deepest point on Earth, but it wasn't hard to find it.",
"That said, as we continue to map the ocean floor in higher resolutions, we may find some small point... | [
"You couldn't have a pocket of air, since at that temperature and pressure, nitrogen and oxygen are supercritical fluids, not gases."
] | [
"Sounds like a good movie. ",
"Deepest cave on earth. Never seen before. They begin exploring, but find something strange. A pocket of air? They can explore further only to encounter what kind of air breathing life lay ahead. "
] |
[
"What is the minimum amount of humans needed for the survival of the species?"
] | [
false
] | I'm burning through Battlestar Galactica at the moment and I wondered if the 41.000 people could actually be sustainable. | [
"40,000 is ",
". Average populations sizes over large stretches of human history were likely smaller than that.",
"You do run into problems at small populations sizes arising from inbreeding and the formation of individuals who are homozygous for recessive deleterious alleles. Each of us probably carries someth... | [
"Does that mean that a population that has been small for a long time is more likely to be stable than the same population that got small over a short period of time?",
"My thinking is that the population that has been small for awhile has already purged \"bad\" DNA from its pool while the population that got sma... | [
"Two, it just wouldn't be a very healthy population!",
"Some research suggests that within the last million years, the human population at times dwindled to as low as 1000-10000 individuals (",
"http://mbe.oxfordjournals.org/content/17/1/2.full",
"), yet we recovered from that. Having many children with diffe... |
[
"How can every point in space be the center of the Universe?"
] | [
false
] | In an astrophysics lesson a while back, while discussing the nature of the Universe, the idea was floated that if the universe is expanding, there must be a point in space where it is expanding away from, a location where the Big Bang occurred. the explanation given for why this is not the case was: every point in spac... | [
"Imagine you are making pancakes, when you put the batter on the pan the heat starts to expand the pancake batter. If you place chocolate chips onto the heating batter then they will all start somewhere on the surface in a fixed position.",
"However, as the batter expands the chocolate chips are not really moving... | [
"When there is no center, the center is everywhere. Or read Crowley's exposition on Nuit and Hadit. (",
"http://books.google.com/books?id=EyflLHPvXSgC&pg=PA23&lpg=PA23&dq=Crowley+Nuit+Hadit+center&source=bl&ots=rQi5PidTxZ&sig=87Hrk_YuAx8AYUNkcs8aD6ImeA8&hl=en&sa=X&ei=8jUqVOnKI46lyAT514KwBw&ved=0CCAQ6AEwATgK#v=one... | [
"Imagine you took an un-inflated balloon, crumbled it up real tight, and put it in your hand. The center, is roughly that small blob of rubber in your hand. When you inflate it, the balloon gets really big. When I ask, \"where is the center of the surface of the balloon\", all points on the surface came from th... |
[
"Have humans evolved in any scientifically significant amount since the beginning of history?"
] | [
false
] | null | [
"Probably the most well-known example of recent and ongoing human evolution is ",
"lactase persistence",
" (aka lactose tolerance). Ordinarily humans lose the ability to digest lactose fairly soon after being weaned. However, among populations of pastoralists more than once a beneficial mutation has appeared an... | [
"http://news.sciencemag.org/sciencenow/2005/01/07-01.html",
"We appear to be evolving defenses against HIV. The link isn't conclusive, but the prevalence seems to be tied to how long its been a threat."
] | [
"Except that the changes are happening in our genome, not the virus's. "
] |
[
"Is there a physical limit to how high an ocean wave can be?"
] | [
false
] | Long story short, I had a dream of a massive tidal wave about to hit the beach. The wave was roughly a half mile high easily. The dream got me thinking if it were possible in the least bit for something that bizarre to happen. Can ocean waves reach epic proportions? if so or if not, Why? | [
"It's completely possible if something large enough struck the Earth in the ocean."
] | [
"Yes, epic waves are possible. The Lituya Bay tsunami was estimated to be several hundred meters tall.",
"http://en.wikipedia.org/wiki/1958_Lituya_Bay_megatsunami",
"This doesn't address the original question though of what the physical limit on the height of a wave might be."
] | [
"The limit of wave height is the depth of the ocean underneath it. A wave breaks when the bottom can't match the top i.e. the wave is symmetrical below the water, and the bottom hits the seabed.",
"If throw a pebble into a lake, you get a splash - which isn't a wave - and after that, waves form."
] |
[
"How exactly did knights in full suits of armor actually go about killing eachother?"
] | [
false
] | [deleted] | [
"Oh dear... how much in detail do you want me to go into that?",
"\nFirst of all; with \"armor\" you mean plate armour, correct? [1]",
"\nIf so, then of course we need to establish (how already others pointed out) that one cannot slice through plate armour. [4] As a result, impact weapons and thrusts were used.... | [
"Going into the early renaissance swords were carried as sidearms the way a pistol would be carried today. The primary weapons were mostly polearms or mauls (warhammer, mace, etc) the polearms of the time had a long thin spike on the top to either pierce plate or work into weak points where the armor was thin like ... | [
"This answer, with the pictures, is awesome. Thank you for this."
] |
[
"Does a propeller plane have any lift advantage compared to a jet powered plane of equal power?"
] | [
false
] | Basically, from my understanding, the high speed airflow from the propellers flowing over the wings would produce more lift at lower speed (relative to the ground), where as the jet counterpart doesn't have the same benefit. It might sound like the fan-blowing-on-sail idea, but I think it is different. Fan-blowing-on-s... | [
"...there's the Bernoulli principle pushing the wings up, but I don't see a force pushing down on the engine and prop.",
"That was the idea behind ",
"channel-wing aircraft",
". You'll notice a distinct lack of airplanes of that type flying today.",
"The air flowing over a wing needs to be at least somewhat... | [
"My PhD research is on propeller-aircraft interaction. ",
"Basically, from my understanding, the high speed airflow from the propellers flowing over the wings would produce more lift at lower speed (relative to the ground), where as the jet counterpart doesn't have the same benefit.",
"Yes. Completely. But prop... | [
"As aero_space mentions in his post, turbulence may play a small role, but in a single engine aircraft, there's another issue. ",
"Rather than simply moving directly backward and outward in a cone shape behind the aircraft as you might suspect, with a single engine aircraft, the airflow likes to adhere to the fus... |
[
"Why does placing a cup of water in the microwave with pizza keep it from being soggy?"
] | [
false
] | So I just learned the seemingly well known trick to keep pizza from becoming soggy when microwaved. What I wonder now is why does this happen? What is it about the extra water that keeps the pizza so fresh? | [
"In my experience, a cup of water can be used to \"absorb\" excess microwave radiation when heating a fairly non-aqueous/dry material.",
"Unsure of the relevance of this to the question, but this idea of a beaker of water acting as a microwave \"sink\" may be useful...",
"Edit: unsure why I'm being downvoted. \... | [
"Actual common reactions:",
"Does it have links to sources?",
"A) No: Downvote.",
"B) Yes: Upvote without even verifying the sources.",
"Possibly better reactions would be:",
"Does it have links to sources?",
"A) No: Search for sources that either prove or disprove OP's explanation. Upvote or downvote a... | [
"Or maybe you could just lower the power level on the microwave for the same result?"
] |
[
"In the photoelectric effect why can't low frequency photons knock an electron to a higher orbit and then another knock it out of orbit the rest of the way?"
] | [
false
] | null | [
"That’s possible, but two-photon processes have a much smaller probability than one-photon processes. You need to excite an atom, then hit the same atom with another photon before it relaxes to the ground state. That’s not easy to do."
] | [
"Note that with a sufficiently bright laser you ",
" do this. It's the basis of a technique called ",
"two photon photoemission",
", which can be used to measure both the filled and empty states of a sample at the same time, and also how long these empty states live."
] | [
"Cool, I assumed it was something ridiculous like that. Thanks :)"
] |
[
"What causes perfect pitch in humans?"
] | [
false
] | The question is essentially, is it a physical aspect of our ears or is it a learned response of our brains to process the data? I ask because I can imagine that if someone had a cochlea which was less 'uniform' or 'stable' then others, this would result in a different response from time to time, changing how their brai... | [
"I'm a musician, and not a scientist, so I cannot give you quite the information you're looking for, but I figure my two cents is worth something.",
"Now, by perfect pitch, I am assuming you mean the ability to hear a pitch and recognize which note it is (as realizing the note is synonymous to realizing the frequ... | [
"Perfect pitch (or better phrased as Absolute Pitch) is believed to have several different causes, some innate (in our brain) and some learned (process). Many people with synesthesia (of audition and vision) tend to have perfect pitch due to their ability to associate colors with sounds. Often these people also ass... | [
"Thanks for your response, I appriciate it as anecdotal evidence leaning towards the learned response side. (Unfortunately, askscience purists will probably be upset becuase \"Personal anecdotes and layman answers are not acceptable posts.\" ... so I await their journal cited responses.. but, until then, thanks!)",... |
[
"Can people with the flu or common cold be asymptomatic?"
] | [
false
] | I've read that people can be infected with Coronavirus and show no symptoms at all. I was wondering if that was also true for the flu or the common cold? Can people be infected but be asymptomatic? | [
"Yes, people often experience a wide range of symptoms (from no symptoms to very severe) for most illnesses including the flu, cold or Coronavirus, depending on a variety of factors including age, sex, genetics, immune health and regulation and many other reasons we don’t yet understand. ",
"Below I’ve pasted a l... | [
"One of those major factors is amount of viral exposure (infectious dose). ",
"Also, the wide variation in asymptomatic people mirrors what we see with SARS-Cov2. If you test for active infection, you will see a smaller proportion of asymptomatic because they probably do not test positive for very long. If you t... | [
"Yeah, that's basically how some vaccines work. Your body is very smart and even small numbers of a pathogen are enough for your body to create antibodies in response to."
] |
[
"I read that our star does not have enough mass to super nova. What other possible outcomes exist for our star?"
] | [
false
] | null | [
"The ultimate outcome is that it will become a red giant, shed its atmosphere as a planetary nebula, and a white dwarf will remain. It is thought that in very very long times, white dwarves cool into black dwarves."
] | [
"I remember reading that it takes something like a 100 billion years for a white dwarf to turn into a black dwarf. Can anyone confirm?"
] | [
"I've heard longer. Either way it's longer than the universe has existed."
] |
[
"Does the presence of steam indicate boiling temperatures? How/why|Why/how not?"
] | [
false
] | I understand the boiling point to be the crossover point of the liquid/gas phases. I understand the freezing point is the start of the solid phase, but not necessarily the end. Is vapor/steam an indication of the boiling point being reached in a piping hot cup of coffee or a hot bowl of soup by a few molecules? Why/How... | [
"Steam is invisible. What you call steam is tiny droplets of water that have condensed because of a change in temperature or pressure.",
"These condensed droplets in the air ",
" indicate that there's warm water nearby, but it might also indicate that the air is very humid, very cold, or that there's something ... | [
"Oh, duh. I feel retarded. I think the original question was posted the day I stayed up all night.",
"Thank you for the brilliant explanations though! ^ ^"
] | [
"Can I start off at asking your cred or source?",
"I had an epiphany reading that. It is dependent on your definition of steam meaning what you say it does.",
"Does it mean steam engines are actually run by rising hydrogen molecules? I jumped a couple of assumptions to arrive at that.",
"Is your definition of... |
[
"Why does IR light penetrate clothing ?"
] | [
false
] | So I heard about Sony Night Shot camera and the whole debacle around it, and it got me thinking about why. I've looked through IR cameras before and the effect was barely noticeable. Why is that camera particularly good at seeing through cloth ? Sensor size? Sensitivity ? High wavelength IR light ? | [
"I'm not sure which camera you're referring to (NightShot is just a generic term for cameras that have the technology, not the name of a specific camera), but the one you're looking at probably has some form of \"IR Illuminator,\" aka an IR light source. Just like flash photography will illuminate a photograph, hav... | [
"Could the ir light/ radiation that our bodies give off naturally boost the resolution?"
] | [
"It wouldn't boost resolution (resolution is a fixed value describing the number of pixels the camera uses to collect the light). A larger sensor means each of those pixels is bigger, thus would collect more light. More radiation emitted by our bodies would also result in a \"brighter\" picture, since more IR light... |
[
"If we were to be able to \"stick\" nuclei to each other without leaving any space between them, how smaller could we make an object?"
] | [
true
] | [deleted] | [
"Pure nuclear matter, like you'd find in a neutron star, has a density of about 3e17 kg/m",
". Mass of the earth is about 6e24 kg. Division gives us a volume of 2e7 m",
". The radius of a sphere with this volume is about 170 m. ",
"So if the earth was pure nuclear matter, it would fill a football stadium. "
] | [
"So if the earth was pure nuclear matter, it would fill a football stadium. ",
"No it wouldn't. AFAIK, all football stadiums are on Earth, and thus would be reduced as well."
] | [
"Incorrect: there is a nonzero chance that there are extant football statiums not on the Earth."
] |
[
"How is an EMP created and what does it do to electronics to not make them work?"
] | [
false
] | I was watching Oceans 11 and it got me wondering what an EMP is exactly. Is it just a huge burst of radiation? Edit: Hey thanks for the response everyone, some very cool discussions here. | [
"It might help OP to explicitly state that changing magnetic fields induce electricity in metal."
] | [
"See here",
". EMP is a rapidly fluctuating magnetic field, which causes fluctuating electric and magnetic fields. It can burn out transistors and other small electronic devices because of the high current it generates."
] | [
"Always the current. Voltage is just the ",
" to cause current. While a large voltage across a circuit will cause damage, it's not the voltage itself that does it... it's the current.",
"Anything that isn't superconducting will resist the flow of current, and the resistance creates heat. The heat then damages t... |
[
"Why can't there be more elements after element 137?"
] | [
false
] | Richard Feynman argued that the last possible element (that is, the element with the highest possible atomic number) would be element #137, because after that the electrons of 1s orbital would have to travel faster than the speed of light. Why is this? Does the electron spin increase in speed as the atomic number incre... | [
"Even disregarding orbitals, if there are no more islands of stability after Z~124 then nuclei above Z=137 would decay by spontaneous fission within nanoseconds.",
"The speed of an orbiting electron is defined as",
"(Z*Coulumb constant*elementary charge",
")/(reduced Planck constant*speed of light)",
"or",
... | [
"the electrons of 1s orbital would have to travel faster than the speed of light. Why is this? Does the electron spin increase in speed as the atomic number increases? If so, why is this? ",
"Quite simple: with atomic number comes protons. More protons means more electric charge in the nucleus. Each electron must... | [
"I know it's not a great first level comment but I'd like to add to your question: couldn't element number 137 just exist solely as an ion?",
"In fact aren't there elements that are like this because of their incredibly short half lives?"
] |
[
"Why is Perfluorodecalin (C10F18), a liquid, breathable ?"
] | [
false
] | The question is worded strangely, I know, but I'm curious as to what makes Perfluorodecalin breathable. As you can clearly see, there is no Oxygen in Perfluorodecalin, so life expectancy couldn't be too long for someone suspended in this liquid. But why are we able to 'breathe' in this liquid, as opposed to other liqui... | [
"It's not the perfluorodecalin that sustains life; rather, it's the fact that perfluorodecalin can have so much dissolved oxygen in it (about 50 mL of dissolved oxygen per 100 mL perfluorodecalin at STP). This is enough to sustain bodily function, which is why it's breathable. "
] | [
"Many perfluorocarbons will hold much more oxygen than a comparable volume of blood; however, most dissolve carbon dioxide even more than they do oxygen, so that's a problem (one of several) that will have to be overcome before liquid breathing can be used in diving, space travel or medicine. BTW, if you've ever se... | [
"The CO2 dissolving is not the main problem with liquid breathing. They solve it by just having a better system of recycling the liquid (heating it to remove all dissolved gasses then re-dissolving fresh oxygen with no CO2). ",
"The biggest problem with liquid breathing is getting all the liquid out of your lun... |
[
"How do color displays create colors that are a single wavelength using only red green an blue? Is spectral yellow the same as the combination of spectral blue, and spectral green?"
] | [
false
] | [deleted] | [
"FWIK It has to do with energy levels that activate which of our rods and cones. Combining red and green wavelengths activate our eyes to see yellow. I'm not sure exactly what u mean b/c all colors are a single wavelength (yellow is 570 nm, I believe). I don't know what u mean by \"spectral\".",
"http://en.wikip... | [
"The light produced by your monitor isn't a single wavelength. It is a mixture of wavelengths that stimulate your cone cells in a similar manner as a single wavelength of light of that colour would."
] | [
"That's correct."
] |
[
"Is Malthus's hypothesis of the global carrying capacity legitimate?"
] | [
false
] | In my opinion, I believe that the human race reacts to limiting factors much like viruses breed in protection against vaccines; the human race's pursuit of constant adaptation will eventually lead to extremely effective solutions to these limiting factors. However, I also believe that this process will indefinitely rep... | [
"Malthusian hypothesis was legitimate in his lifetime. Pre-industrial populations behave just like Malthus predicted. He was essentially correct in his observation. However, technological developments already happening in his lifetime changed things dramatically. ",
"Current predictions for population growth... | [
"This article",
" might be what you're looking for, it explains the current predictions for global population growth and has links to supporting studies.",
"To summarize it, the world's population is expected to reach a maximum of 10 billion and then could actually begin to decline, mainly because of increased ... | [
"Strictly speaking one could still argue that the Malthusian hypothesis holds, but that the carrying capacity has been increased through technological innovation. The problem comes with the fact that the vast majority of the planet's population has a living standard far below that of the west. So for instance if ev... |
[
"Will photonics ever replace electronics?"
] | [
false
] | My high school physics teacher, who was also a technology geek, always told us that photonics would inevitably replace electronics in the next decade. Well, here I am and it seems like there have been no real advancements. So what is the primary limiting factor of photonics? Is there no economical way of manufacturing ... | [
"Hopefully, yes. There's a lot of research being done on it. The big challenge is that light is much harder to control than electricity - how do you build an optical transistor (there's lots of ideas, but no clear winners), how do you make it microscopic, and how do you integrate it onto a chip."
] | [
"Firstly, that's a super vague statement to say that \"photonics will replace electronics.\" Is a light bulb an electronic or \"photonic\" device?",
"I supposed by some definition, \"photonics\" are already in heavy use for data transmission; fiber optics have largely replaced electric conductors as the medium of... | [
"All computing has been based on a switching mechanism. Mechanical computing, current electrical computing have some sort of transistor. There are pneumatic mechanisms with pilot valves which act as transistors making a kind of fluid based logic. Light based computing is missing a fast transistor element. There are... |
[
"If plastic is largely made of carbon, and it takes forever to degrade.. then doesn't this make plastic a pretty effective carbon sink?"
] | [
false
] | Implication being: the use of plastic (assuming it's properly stored) is currently a more environmentally friendly use of fossil fuels than combustion. | [
"Carbon sinks usually absorb CO2, where Plastics are made of hydrocarbons. While making plastic will keep the CO2 from combustion, it won't really sink any carbon, as the CO2 was never released. The main purpose of carbon sinks is to store CO2 from combustion, CO2 is VERY hard to get back into a hydrocarbon form, m... | [
"Let's not forget it takes energy to produce plastic. It's not just 10 units of carbon out of the ground-->10 units of carbon as plastic. It would be more like 15 units of carbon out of the ground-->5 units combusted for energy and released to the atmosphere as CO2 + 10 units as plastic (and it's probably not that ... | [
"The carbon is currently locked safely away as oil. we could leave it in the ground, or we could make stuff out of it. for example, combustible fuels and plastics (sure, other stuff too). if it is burned as a fuel for electricity or transportation, the carbon is released into the atmosphere and contributes to warmi... |
[
"Could a space probe travel so far from anything, that eventually everything will be moving away from it at faster than the speed of light?"
] | [
false
] | Voyager 1 apparently is about to be (or already is) the first man made object to leave our Solar system, which got me thinking... From my current understanding of cosmology, the accelerating expansion of space will one day drive everything not gravitationally bound to us* away from us at faster than the speed of light.... | [
"Yes.",
"This will happen soonest in the ",
"voids",
" where there are no galaxies. To get there we need to escape the galaxy, which means getting to something like 500+ km/s. I'd have to do more math than I care to do at this moment, but I think we could build such a craft with current technology by poweri... | [
"In theory such a trajectory may be possible, but it would have to enter the void very very slowly, which means only just barely escaping the milky way and its cluster, which makes navigation calculations harder, verging on chaotic."
] | [
"Thanks for your reply! I'm completely lost at the math for this, mainly because I wouldn't know where to find and how to interpret all the data required to say anything that makes mathematical sense.",
"Would it really have to slow down though? Might it be possible to plan the journey in such a way that it would... |
[
"Couple of questions on evolution."
] | [
false
] | Ok, so I stumbled on video and was wondering what the scientific community's view is on it. Since it's from "Answers in Genesis" I've pretty much already assumed it's biased. After looking through some of their other, clearly biased views on subjects. So, is there an answer for: 1.) Does the scientific community know w... | [
"And, is it true that there is no known way for genetic information to be added to the genetic code of an organism?",
"That's either wrong, or \"not even wrong\" because it doesn't mean anything.",
"Here's some DNA:",
"ACGTACGT\n",
"Oh look, ",
"a copying error inserted a base",
":",
"ACGTTACGT\n",
... | [
"Just to add...",
"One of the common ways \"information\" is added to the genetic code and allows for new genes and new functions to arise is by gene duplication.",
"Say we start out with 1 gene that has a specific function. Through random error, that gene is duplicated. Now we have 2 of the same gene, but only... | [
"We don't know for certain precisely how life started, but we know it's possible to form the building block chemicals relatively easily. From there it's just chemistry and happenstance over millions of years. From the information we have on the earliest identified life on the planet we also can conclude that abioge... |
[
"Why are computers always using multiples of 8?"
] | [
false
] | For example: 8 bits = 1 byte. 1024 bytes is one kilobyte. There is also 16-bit computers, 64-bit, computers. And so on. Why are they always using multiples of 8? Edit: yeah thanks now I realize 1024 bytes is one kilobyte Edit2: thanks for answering guys. It all makes sense now. | [
"Largely for convenience.",
"Computers are binary machines and everything works based on switching transistors between one of two states (typically referred to as 1 and 0). This means that the most natural number system to use is in computing is base 2. This means that it's typically easier to work with computing... | [
"Its not multiples of 8, it's powers of 2.",
"2",
" = 1",
"2",
" = 2",
"2",
" = 4",
"2",
" = 8",
"2",
" = 16",
"2",
" = 32",
"64,128,,256,512,1024....",
"This is due to binary computing and digital logic. Basically computers are set up to only tell the difference between if a line has v... | [
"It's actually based on powers of 2 :)",
"8 is a power of 2, as are 16, 64 and 1024.",
"See ",
"Binary",
", which is the format in which computers store and process information."
] |
[
"What happens to the light that is absorbed?"
] | [
false
] | So I was watching this video and they said "Light Absorbed". What does that even mean? So when a surface absorb light what happens to that energy. Does it increase the potential energy of the surface. | [
"Lot's of things can happen to light when it is absorbed. The most common thing is for the light itself to be destroyed and its energy is converted to heat (increased random kinetic and potential energy of the atoms). Most of the light coming out of your light bulb strikes the objects in your room and is converted ... | [
"Yes basically. You can transfer the energy of the light (and hence destroy it) by either kinetic vibrations which then travel and dissipate through the material or by the absorption->re-emission->re-absorption by a different atom->re-emission etc until all the energy is dissipated."
] | [
"Light can be absorbed by a molecule (e.g. chlorophyll). The energy from the light excites an electron from its ground energy level to an excited energy level. For most compounds that absorb light, the electron simply returns to the ground state and the absorbed energy is converted into heat, in which case you can ... |
[
"What would the result be if 2 \"perfect\" chess computers played eachother?"
] | [
false
] | If both computers calculate every possible move the coming 10 000 turns. Would it always end in a draw or would it be 50/50? Or would one side win all the time? | [
"Chess has not been \"solved\" yet, which means we don't know the answer to this question yet. It's currently beyond the limits of our computational resources, and is likely to be so for a while longer. Smaller sub-problems have been \"solved\" though: We have calculated the perfect play for every possible board st... | [
"Pawn advances/promotions also reset the 50-move clock. Two different calculations came up with slightly different numbers both just under 6000 ",
"[1]",
" ",
"[2]",
". Finally, ",
"here's a pastebin",
" with the PGN of a \"longest possible game\" of a different length than the other two calculations: 5... | [
"That site is wrong, there is the 5 move repetition rule which forces a draw."
] |
[
"When lightning strikes a body of water, why doesn't everything living in it die?"
] | [
false
] | [deleted] | [
"It doesn't kill everything in the lake, it just kills everything near the strike point. ",
"I've never heard that being in a lake during a lightning storm is more dangerous than anything else."
] | [
"I swear this question gets asked every 3 days here...",
"Creatures in the water will likely not die from a strike. In order for current to flow through a given volume, there needs to be a potential across that volume. Fish and the like are quite small. Couple this with the fact that the intensity of the electric... | [
"Please follow the rules and do a search",
"."
] |
[
"What do we know about wounds to pregnant women and their fetuses?"
] | [
false
] | What complications take place when a pregnant woman is wounded in her uterus? How dangerous is this to the mother? Can fetuses survive trauma to the womb? The whole state of pregnancy seems very fragile. | [
"Ok, I will try my best to address this. If the uterus is punctured, but the womb is intact, it would be most likely that the woman would be hospitalized to prevent any infections. As long as vital signs and infection can be controlled the pregnancy would continue until such a time the baby or the mother become end... | [
"I'm sorry, but due to the complex nature of a pregnancy, to answer your question with any real detail, more information is needed on type of wound, when it was sustained, at what point in the pregnancy, time until treatment, and nature of injury. If you have a specific scenario in mind, it would be much easier to ... | [
"How about 6 months in, and the uterus being ruptured from the outside by a sharp object, with immediate medical attention?"
] |
[
"Why is space \"cold\"?"
] | [
false
] | null | [
"Im my mind, if there cant be warmth there cant be cold as well, and space would be a nothingness of \"thermal energy\" ",
"You're right, temperature only makes sense for matter. In a vacuum there is no temperature.",
"The temperature of an object in space (e.g. a satellite) is determined actually by thermal ra... | [
"Katinla has a pretty good answer and you're certainly on the right track. Cold really doesn't exist. It is simply the absence of heat. Just as dark doesn't exist. It is the absence of light. Without matter to absorb energy there can be no kinetic vibrations, and thus no heat, so in order to define a temperature it... | [
"In a vacuum, there is no temperature.",
"This is not necessarily true. Radiation can still create a temperature"
] |
[
"When I first get in the shower, if I keep my feet in the same spot for a few minutes, they want to stick to the floor. What is going on here?"
] | [
false
] | null | [
"For science you should try doing this for the same duration without any water."
] | [
"And he was never heard from again. "
] | [
"From my experiences, OP seems to be referring more to adhesion than a suction/vacuum effect."
] |
[
"Can other species contract STIs?"
] | [
false
] | I don't mean in a weird bestiality way, I'm wondering if other animals have their version of STIs the same way we do. Kinda random question, but it' s something that's crossed my mind a few times. | [
"Yes. For example SIV (the primate version of HIV) has been around a lot longer than HIV is thought to be the ancestor of HIV. It is used often in research and in many species which it infects will not cause simian AIDS."
] | [
"Other similar viruses include FIV (felines), EAIV (horses), and Visna (sheep), all of which are related to HIV. Chimps can also contract hepatitis C.",
"Herpes viruses are also extremely common, and many are transmitted sexually by animals (but not always). Pappiloma viruses (warts) and chlamydia are also comm... | [
"One of the coolest ones is the Transmissible Venereal Tumor of dogs (TVT). Its actually a truly contagious cancer, the cancerous cells themselves are spread between animals. ",
"Major ones in livestock due to abortion risk are various species of campylobacter, chlamydia, leptospirosis, coxiella, trueperella, con... |
[
"How much do we know about the cause of sexual orientation?"
] | [
false
] | [deleted] | [
"We know very little about it. It's definitely not genetic, or at least not mostly genetic. There may be some genetic contribution, but that's certainly not the whole story. My theory: it's a developmental alteration. There's an unexpectedly high concordance of being gay with being left handed. Left handedness... | [
"Just to nitpick the premise: zoophilia is a kink, not a sexual orientation."
] | [
"Just off the top of my head I remember reading a study that correlated increased testosterone levels during fetal development with homosexuality. By no means conclusive, but definitely supports the idea that it's developmental. Would love to see if anyone could find this particular paper or others similar."
] |
[
"If humanity reached Mars and were to fart every fart they would ever fart collectively at one time how long would it last, and would it be enough to melt the ice caps and begin terraforming the planet?"
] | [
false
] | null | [
"There is no way to copy a post on reddit. You will have to make a new post."
] | [
"Please post calculation requests to ",
"/r/estimation",
" or ",
"/r/theydidthemath",
"."
] | [
"How does one repost?"
] |
[
"How do we know it took 300,000 years after big bang to have an observable universe?"
] | [
false
] | I only started educating myself on this topic a few days ago. Please enlighten me on this question. Thanks | [
"We use General Relativity to construct the expansion history, from which we can make statements about how density, temperature and pressure depend on time. We also make use of a whole lot of statistical physics, thermodynamics, and field theory to compute the moment where the free electrons and protons combined to... | [
"I understand that part but how do we know it took 380,000 years for the plasma to cool down?"
] | [
"It's 380,000 years.",
"We cant see further back than that because before then the universe was entirely made up of plasma. Plasma is opaque to electromagnetic radiation because it is made up of charged particles. We see last vestiges of this epoch as the cosmic microwave background.",
"At about ",
" 750 Mill... |
[
"Is there really that much of a chemical difference between bathroom cleaner and kitchen cleaner?"
] | [
false
] | So I've got bathroom cleaner in the bathroom, kitchen (all-purpose) cleaner in the kitchen, like most people; but say they got mixed up, would it really matter ? Chemically, is there really that much of a difference or is it all marketing, as in, could I potentially use one cleaner for everything or is there a reason ... | [
"Bathroom cleaners tend to contain bleach, which is intolerant of acidic environments. To remove limescale, a separate acid material like oxalic acid or dilute hydrochloric acid is needed."
] | [
"My uneducated guess (I see how this will become my standard starting phrase here) is that both have very similar main ingredients: Anionic surface agents (that's the translation of the german name, at least) which cause hydrophobic materials like fat to be solvable and thus removable by water. Bathroom cleaner wil... | [
"Limescale. Rust. Ground-in dirt. They're a challenge for ",
" household cleaners, but not for Cillit Bang!"
] |
[
"With oil and natural gas extraction - what happens when energy input > energy output?"
] | [
false
] | I frequently hear that its becoming more expensive to get to sources of oil and natural gas, but is there an issue with the energy as well? What happens when the energy output of drilling/fracking is too little for the energy spent? I assume it is still valuable for raw materials. Will we be using renewables for extrac... | [
"I'm not aware of direct measures of input vs output in terms of energy. This is usually discussed and considered by petroleum companies in terms of economics, so basically when the cost of extracting is greater than the profit made by selling the product, you stop producing. To a certain extent, the various energy... | [
"If the energy paid for the extraction is more than the value of whatever is being extracted, then the company will no doubt stop drilling in that location. Of course they probably do all kinds of analyses to figure this out first. Economic balances are a fundamental principle in engineering fields. ",
"It wou... | [
"It would make little sense to use renewables for extraction directly (other than whatever happens to have been produced as electricity within the grid - everything just gets pooled together, balanced, and distributed), as they are usually much more expensive to produce than getting free petroleum or natural gas ou... |
[
"When you are developing in the womb, how does your body know which way is up?"
] | [
false
] | I'm aware that the Hox gene has something to do with orientation but I would like to know how this process works; what does your body do that allows it to know up from down? Thanks! | [
"Hopefully, a developmental biologist will chime in and give you a more detailed response. Until then, I'll give it a go.",
"There are a number of different strategies that organisms use to develop developmental axes - for us chordates, the primary axes are dorsal/ventral (front/back) and anterior/posterior (head... | [
"Why would a fetus need to know up from down? Are you asking how a fetus develops that sense for use after being born?"
] | [
"The question basically is \"why does your head develop as a head as opposed to your feet?\"",
"From what I can remember of my embryology classes, it isn't fully understood, but when we begin as a ball of cells, they all produce cytokines, and depending on the amount of cytokines, cells differentiate into differe... |
[
"AskScience, I need your help finding a paper."
] | [
false
] | I am writing a story right now in which the main character is out to prove that the world he lives in is merely an ultra-realistic simulation of Earth. (This Earth however is affected by massive social infrastructure collapse, basically a dystopia. Humans live in small settlements separated by thousands of miles, urban... | [
"An Oxford Professor of Philosophy has in fact come up with a well-known \"simulation argument\".",
"His website is here :",
"http://www.simulation-argument.com/",
"The paper itself here: ",
"http://www.simulation-argument.com/simulation.html",
" (Published in Philosophical Quarterly (2003), Vol. 53, No. ... | [
"Why not? It's hyper realistic. The most accurate measurement we ever took is something like 16 decimal digits. Any calculator can calculate 100 digits of pi no problem.",
"@OP: I don't think it's possible to distinguish your reality from a simulation through any experiment. Any result could just as well be a con... | [
"This may be the best option. Because its fairly easily testible, and the results are straightforward. "
] |
[
"If I was on a train that was going 20 mph, and I began walking toward the front of the train at 5 mph, am I now going 25 mph?"
] | [
false
] | The example can be switched and isn't the only one but, my friend and I were having a debate on something similar to this. It was sparked by him mentioning that his high school science teacher said that you cannot move faster than the vehicle you are in. I told him this was true, and obviously he disagreed. While I'... | [
"If I'm going at 5mph through the carriage of a train going at 20mph, our intuition tells us I'm going at 25mph overall. Fair enough.",
"But what if the train's going close to the speed of light? If it were going at 51% the speed of light (c) and I'm moving at 50% c, would I be going at 101% c in total?",
"When... | [
"If I was on a train that was going 20 mph, and I began walking toward the front of the train at 5 mph, am I now going 25 mph?",
"Yes, you are now going 25mph with respect to the ground.",
"his high school science teacher said that you cannot move faster than the vehicle you are in.",
"I do not know the conte... | [
"Just as a bonus (because relativity is brought up on this sub so much) the error from not including relativistic effects is 4*10",
"mph"
] |
[
"[Weekly Discussion Thread] Scientists: What is it like working with other scientists (or, what are we really like?)"
] | [
false
] | This is the thirteenth segment in our weekly discussion series, and today, we're going to talk about what scientists are really like in the real world. The only time that the public really sees us is when we are on a news show or some movie, and it is almost never truthful to what scientists are really like. So, in tha... | [
"My background is that I have a bachelors degree in physics. I currently work for a physics publishing company, primarily with a bunch of other physics educated people, but none of us are actively doing research. Most of the editors and writers have physics backgrounds. I do web production. I have been here just ab... | [
"In my experience astronomers (which I use as a broad collective term that includes planetary scientists and solar physicists) are normal people that come in a range of attitudes, backgrounds, and beliefs. They are people first and scientists second! I've met astronomers who are dancers, artists, bakers, brewers,... | [
"PhD in atmospheric science. I've had the opportunity to do basic research in geophysical fluid dynamics as well as work with federal agencies in improving operational weather forecasting.",
"I think a better predictor of the personalities of your coworkers is the place you are working, rather than their level o... |
[
"Why do drinking glasses ring when you rub your finger around the outside?"
] | [
false
] | is it actually the glass vibrating or the water against the glass? What hapening? | [
"Technically, it's the entire setup, glass, water, table and even your finger to a small degree. But functionally, the glass is vibrating and the water is helping control the natural frequency. What's happening is the small amount of friction from our finger is causing the molecules in the glass to oscillate back a... | [
"I don't know the details, but the amount of water does affect the pitch of the note, most likely due to changing the length of the glass which is resonating. The water then acts like an adjustable node, defining the wavelengths of sound which are produced (the fundamental and the higher harmonics).",
"http://ww... | [
"This is an effect called resonance- many vibrating bodies \"want\" to resonate at a specific frequency. When excited near that frequency, they will resonate at that frequency until it dissipates. ",
"It's similar to pushing a kid on a swing. If you push too rapidly back and forth or too slowly, the kid won't ... |
[
"How does nuclear fusion of hydrogen into helium work?"
] | [
false
] | I know that it involves deuterium and tritium fusing together to form a helium atom and giving off a neutron, but what other processes are involved? For example, in what way does E=mc come into play? What is the mass that is being converted, and why is said energy measured in electronvolts and not in joules? | [
"In the Sun there are ",
"three main paths leading to helium production starting with hydrogen",
". A forth path is so rare (0.3 ppm) that it hasn't been observed. Deuterium and tritium are intermediate products. The total weight of the 4 original protons (H",
" ) is greater than the mass of the resulting hel... | [
"So how are deuterium and tritium formed? Where exactly do the neutrons come from?"
] | [
"Two protons fuse, and almost immediately beta",
" decay from He-2 into H-2 (deuterium). In beta",
" decay, a proton is converted into a positron, neutron, and a neutrino."
] |
[
"Why is there the same medical dosage if you weigh 120 lbs. or 350 lbs?"
] | [
false
] | Whenever anyone buys medicine, there is usually instructions on the back to take a certain amount irrespective of the size of the adult. If you get prescription drugs, the doctor may adjust the prescription based on your size, but if you buy over-the-counter medicine, such as for allergies or flu, just one adult dose i... | [
"In terms of how doses are determined: for most drugs, early-phase clinical trials required for FDA approval are where the ideal dosage is determined. The issue with that is that early-phase clinical trials are done on healthy volunteers (read: having no other major health problems, including obesity). So when the ... | [
"Thanks for all that effort.",
"I noticed it with Claritin as several people I know just began taking it (spring pollen is here).",
"Personally, I'm probably an outlier as I weigh 245 lbs. but have only 15% body fat (caliper method - which I started doing as I was visually noticing changes on a different diet/e... | [
"Yes, thanks for that. I feel much more comfortable giving what I consider to be \"general education\" or \"general advice\". "
] |
[
"Could a single individual ever have multiple mitrochondrial (or chloroplast) haplotypes?"
] | [
false
] | I know individuals bear a single mtDNA haplotype inherited matrilinealy, but would it be possible for a single individual to have multiple mtDNA haplotypes? If so, are there examples of this? | [
"Yes, the technical term for this phenomenon is ",
"heteroplasmy",
". It can be inherited from the mother, or it can arise later, as mutations arise after fertilization. ",
"In some species, mitochondria from the father's sperm can make their way into the offspring, but it's still the subject of debate whet... | [
"Yes, any mutation that occurred after the first division of an embryo would propagate through all the daughter cells from that particular cells line, so a mutation when the embryo is only two cells in one of the cells mtDNA would would leave half of the mtDNA distinct from the other half. another method and specif... | [
"Although we are often taught that a woman passes on just one type of mitochondrial DNA, an egg can be hetroplasmic as well. Work showing this goes back decades, although most work has been done in cows and fruit flies. One paper that I think is pretty neat is ",
" December 1, 1987 vol. 117 no. 4 687-696 (",
... |
[
"Are there non-von Neumann computers? If not, why did the architecture need a name? It's not as though there's a dearth of things named after von Neumann."
] | [
false
] | null | [
"Depending on context, ",
"Harvard Architecture",
" would be non-Von Neumann."
] | [
"As i understand it, \"von Neumann architecture\" refers to computers which keep program and data memory together rather than in separate banks, so that the one is just another kind of the other.",
"Interesting to note is that modern computers have sort of rejected the complete merging of the two and re-implement... | [
"I wouldn't include JIT translation in self-modifying code, as it's typically performed by the runtime instead of the program being executed."
] |
[
"It's my understanding that when we try to touch something, say a table, electrostatic repulsion keeps our hand-atoms from ever actually touching the table-atoms. What, if anything, would happen if the nuclei in our hand-atoms actually touched the nuclei in the table-atoms?"
] | [
false
] | null | [
"When two nuclei touch, nuclear fusion occurs, so ignoring reality the two would fuse together.",
"Bringing reality back, in the process of getting those two nuclei to touch has more than likely ",
" obliterated you, the table, and anything nearby, because fusion takes an insane amount of energy.",
"Edit: Sin... | [
"Yes, the only problem with them currently is because of the energy requirements to fuse nuclei the reactors have a negative net energy. There's been a lot of work and research on lower energy fusion but none of it has resulted in a reliable power source, yet.",
"Edit: Yes, stars, hydrogen bombs, and other fusion... | [
"So fusion reactors are basically just trying to make the atoms touch?"
] |
[
"Where do calories come from in foods that have little to no macronutrients?"
] | [
false
] | So for instance, spiked seltzer shows 170 calories per can, but no fats, 2 sugars and no proteins. What does our body metabolize that is not a fat, carb, or protein? | [
"Alcohol has an Atwater coefficient of 7kcal/g"
] | [
"Ethanol is metabolized almost identically to fructose. No tissue uses either to do mechanical work. The liver metabolizes both ethanol and fructose into fat at a loss of about 70% of the original calories. That fat becomes both globules embedded in the liver and plasma triglycerides. The fat will eventually b... | [
"Great! This makes sense, appreciate the link as well!"
] |
[
"How much water would a 4-dimensional hypercube displace?"
] | [
false
] | A tesseract is 8 cubes folded into a hypercube. It would appear as 2 interconnected cubes when projected into the 3rd dimension. I believe that if created by folding the cubes into one another in a higher spacial dimension, it would be "hollow" but still take up the same amount of space as an actual hypercube, like 6 ... | [
"Let's think about the analog of a 3-dimensional cube intersecting a 2-dimensional space. How much 2-dimensional water would it displace? This would depend on the orientation of the cube. The analogous issue would hold in your case: it would depend on the orientation of the hypercube when it intersected the 3-di... | [
"I am a total layperson, but following fishify's suggest, I am picturing putting a rubik's cube through a flat plane (say, a sheet of water that can only be displaced into the x and y axes.) You could put the cube into that sheet corner-down, and displace a triangle-spaced area; you could set it flat on a side, an... | [
"An interesting follow up question is, what is the maximum volume that can be displaced by a unit hypercube?",
"Turns out to be sqrt(2), independent of the dimension of the hypercube.",
"Source: ",
"Cube slicing in R",
" Proc. Amer. Math. Soc. 97 (1986), no. 3, 465--473."
] |
[
"How do I improve my gas milage using physics?"
] | [
false
] | I take a 6 hour drive every month or so, and I tend to coast uphill and accelerate downhill. I also accelerate slowly. I drive a standard, so I have control over coasting. What methods could I use to increase my fuel economy assuming my car is in perfect shape especially in regard to hills? | [
"Golf ball dimples all over the car"
] | [
"Profile drag increases with the square of velocity. As such, the single biggest thing you can do to save gas is slow down."
] | [
"Your trip will also be only half as long, and there is no exponential scaling. It's a linear scaling for small velocities and a quadratic scaling for larger ones. I mean obviously, \"the slower the more efficient\" can't be true, because I highly doubt going at 1mph with a car is more efficient."
] |
[
"In Biology we learned about how the different sensory organs in the body require balances of different ions to function. For example, the inner ear has a membrane full of K+ rich fluid. Can we infer then that a lack of needed ions in the body then causes a decrease in senses?"
] | [
false
] | So if you lack potassium, would your hearing be affected? Or does your body prioritize where it sends certain ions to capitalize on critical functions like the senses and base survival needs? | [
"There's a class of diseases called channelopathies that result in dysfunctioning ion channels; these can include conditions such as general epilepsy and ataxia. This doesn't quite answer your question, but it does provide you with an interesting area of literature if you're hoping to investigate this idea further!... | [
"There’s a whole bunch of regulatory mechanisms going on that would prevent neurons and other ion-dependent systems from shutting down from a dip in calcium or potassium. I reckon that at the point where your body can’t find ion reserves anywhere and your nerves start becoming affected, there is something seriously... | [
"Ions are extremely important. But it all depends on the correct concentrations. Sodium and potassium currents are needed for nerve impulses. In the heart, you need additional calcium currents. Taste depends on ion flow as well. Thus, Calcium imbalances can have major effects. But this is where the kidneys are impo... |
[
"Did leprosy ever go away in the past on its own?"
] | [
false
] | I was doing some reading and I started to wonder, can leprosy go away on its own back before antibiotics? Did everyone that get it have it their whole lives, or did some people fight it and wind up without the disease? I tried to look the information up, but every website wants to tell me the modern day cures for lep... | [
"When a disease goes away on its own without treatment, they call it “spontaneous remission.” That’s the search term I used to learn that yes, leprosy can go away on its own. It also doesn’t have to progress from its earlier stages to its more advanced stages.",
"For more about leprosy, check out the This Podcast... | [
"It's also interesting to define what you would consider leprosy. Would you consider it having the lesions associated with it? Or is just contracting the bacteria without the lesions enough? Because if just contracting the bacteria is enough, then fighting it off without signs of infection is actually far more comm... | [
"I would offer that improved hygiene and quality of life are the largest factors to the control of that disease.",
"The pathogen, I was taught, is rather 'lazy'. Takes a lot to become 'colonized' -- mount an immune response that has you demonstrating pathologies.",
"If you mean 'spontaneous remission': not so m... |
[
"Why does salt enhance the flavor of pretty much everything?"
] | [
false
] | null | [
"Not an Expert so here is a completely low level explanation.",
"Sodium ions can directly travel to ion channels in taste receptors, making them easier to activate and send the signals along to the brain. An analogy I have heard is that salt \"turns up the volume\" of a dish.",
"A strange thing to note is that ... | [
"NAE, but I remember reading that salt dampens or cancels out some flavors, while leaving others alone. So if a dish is too bitter and not sweet or tangy enough, a little salt will dampen the bitterness and therefore bring out the sweetness or tanginess.",
"That's often why there is a little salt in hot chocolate... | [
"salt tastes great because sodium, and to a lesser extent chloride, is the most important ion regulating the water balance in your body. consuming it frequently is a practical necessity, and in the wild salt is relatively scarce. so we evolved to love the taste of salt, and neurologically it tastes good no matter w... |
[
"How do frogs avoid getting poisoned when they eat poisonous insects?"
] | [
false
] | null | [
"Let's flip it around.",
"How the hell can you eat chocolate and NOT die?? To dogs, eating enough of it can kill them straight out.",
"\"In large enough amounts, chocolate and cocoa products can kill your dog. The toxic component of chocolate is theobromine. Humans easily metabolize theobromine, but dogs proce... | [
"Which is an interesting point of view because believe me, these frogs eat A LOT. They spent almost all their time awake hunting for prey. They must indeed have built up a very high tolerance. Batrachotoxin, which is the pdf toxin is deadly to all but themselves and even their only natural predator, the Leimadophis... | [
"I also eat a lot of chocolate without dying ;)",
"More serious : if it blocks a sodium channel, my guess would be that it only blocks a sub type . Since there are several types of sodium channels , this could be easily avoided by the organism by using another Subtyp ( and live with the other downsides of that su... |
[
"I have basic knowledge of the double slit experiment, but I still have a couple of questions about the logistics of it."
] | [
false
] | First off, did we do calculations and figure this was hypothetical, then constructed the experiment that confirmed it (and raised more questions)? Or did we just decide to try it/stumbled across it? Secondly, how far apart can you make the slits before the photon will start acting like a particle 100% of the time (and ... | [
"I have a few related questions if you'll permit me to ride this thread -",
"Has there been any investigation into potential effects caused by:\na. the depth of the slit?\nb. the properties of the slit material (density, capacitance, etc)?",
"For instance, is there any subtle difference on the result if the sli... | [
"But they are the same thing."
] | [
"What if the interior of the slit is coated with a highly reflected material inside of the deep 10mm slit? "
] |
[
"Can alcohol gel hand sanitizer stop viruses?"
] | [
false
] | In 2009, during the swine flu outbreak, alcohol gel was widely recommended as a way to prevent the illness, but can it really stop viruses? Since viruses aren't considered living beings, i assume the only way to stop them is to interfere with their metabolism. Is hand sanitizer able to do that? | [
"Not their metabolism, they do not metabolize as virions. ",
"When you interfere with their structure, the structure of the viral capsid which is proteinaceous in the case of naked viruses, or their envelope- which is made of lipids similar to a cell membrane then they will be inactivated. Alcohol can denature b... | [
"I see. ",
"The structural damage is deleterious. ",
"In the event that the virus could enter a host cell (and get it's genome to the appropriate site in the cell based on the kind of virus) I do not think that its environment prior to ingress would have any effect on its replication. "
] | [
"/u/meowmerson",
" said what I was going to say very well, but I'd just like to add the point that viruses may be 'alive', depending on which virologist you ask... It's a organism description which really doesn't work that well with viruses: my university virology lecturer told me that he thinks the concept of 'a... |
[
"Do humans have bacteria in their body before birth?"
] | [
false
] | Bacteria are commonly found in the human body. It's easy to guess (correct me if I'm wrong) that babies pick up their first bacteria from the environment around them, but what about the bacteria inside their body? It's unlikely that we collect the right amount and variety of bacteria to populate our guts, for example. ... | [
"https://www.frontiersin.org/articles/10.3389/fped.2015.00017/full",
"Babies might have some gut bacteria before birth, but they definitely get most at birth. They don’t acquire a “right” set of bacteria, they acquire what is in the environment around them that can survive in the gut, and it definitely can vary."... | [
"There is also a difference in the microbiome of babies that were born naturally vs c-section"
] | [
"Yesterday I followed a college about this!",
"Babies are as good as sterile when they are in the womb. Actual colonisation happen after birth. Either from vaginal flora or skin flora with a C-section.",
"This does not make a difference in the long run, since after about 6 months, the flora is as good as stable... |
[
"Recenrly read an article that said the highest temperatur reached by humans was inside the LHC and was 100.000 times hotter than the core of the sun. How could the LHC do this without melting itself and its surroundings?"
] | [
false
] | null | [
"The amount of material that's at that temperature is very small."
] | [
"Wouldn't this huge temperature, even if its concentrated at a small area, heat up everything around it?"
] | [
"The beams do deposit energy into the surroundings whenever particles are lost. The beam dumps are designed to handle localized heating for when the beams are dumped."
] |
[
"How do ants coordinate digging/tunneling with one another?"
] | [
false
] | Can someone explain to me how ants coordinate making a tunnel/chamber system with one another? I am working on an ant behavior sim and for the life of me can't get them to create a tunnel system without cheating (adding behaviors that are too 'smart' for ants). I've managed to emulate foraging, caring for young, defens... | [
"If a leaf-cutting ant is about to engage in excavation work, it sends vibration signals traveling along the ground and tunnel walls. It starts producing these signals seconds before starting to dig itself and continues to do so as long as it is busy. Other ants receiving the vibrational signals will join the noisy... | [
"does the hive, or rather the workforce of the hive, follow some sort of algorithm to create the layout of the tunnels, or do the just come about depending on the needs and surroundings? (What I mean by surroundings is that for example the soil on the left side is easier to get trough than to the right so they buil... | [
"Ants use pheromones to communicate with one another.",
"According to Wikipedia : A\npheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of... |
[
"What effect will our modern environment and lifestyle have on the future evolution of our species ?"
] | [
false
] | Since we have become able to correct certain genetic defects and basically eliminated survival/reproduction of the fittest, are we at risk of becoming flooded with more and more instances of disease and defects that, in the past, would have led to those traits not being reproduced? Are we destined to be a race of overw... | [
"Nope, more breeding pairs actually ",
" our chances of survival as a species in the event of a global catastrophe.",
"Too tired to explain right now, but think of it this way (and this is gonna be a ",
" analogy):",
"You've got Two teams:",
"Team A's got 2 billion people who are all really good at basket... | [
"Can you explain how reproduction of the fittest is not compromised by our ability to correct a disorder that, in the past, would have resulted in those genes being eliminated from the gene pool, but now have about the same chance of being passed on? ",
"How is healthy people breeding with the unhealthy not worse... | [
"Well first here's a bit of a rundown of random stuff.",
"Height is correlated with intelligence",
"Attractiveness is correlated with intelligence",
"intelligence is correlated with reproductive success, and so are the other two",
"Correlation doesn't equate causation though, they've all got outside influen... |
[
"Does the probability in deal or no deal work similarly to The Monty Hall Problem? [Please see inside for details]"
] | [
false
] | I'm going to assume whoever is going to answer this for me is familiar with the Monty Hall Problem. Please help me understand the following: In the game show Deal or no Deal there are 26 cases. Now if I pick a case, the probability that the case I picked has the $1M is obviously 1/26. Now as I keep opening cases and se... | [
"The big question is: does switching the case at the end increase the probability of me winning the $1M from 1/26 to 25/26 (in other words it works like the Monty Hall Problem) or is it 50/50 chance at the end.",
"50/50. (Anyone saying otherwise do not understand the MontyHall problem ...)",
"You can sum up the... | [
"no. the key about the monty hall problem is that he ALWAYS selects a non-winning case to identify. in your case, since you had a chance of selecting the million dollar to eliminate, there is instead a 50% chance that either case left has the 1 million.",
"it's a subtle difference that has huge implications in th... | [
"Furthermore, in Deal or No Deal, the presenter and people opening the boxes do not know which box contains the million (and which boxes don't), which makes it different from the Monty Hall problem (that is, the presenter cannot assist the contestant by revealing losing boxes)."
] |
[
"Question on Relativity and Velocity?"
] | [
false
] | I am no physicist and my knowledge of the subject relies on videos and lectures I have seen on YouTube. Here's my question. a. As per Einstein's theory, all motion is relative. That is, if you have two bodies A and B moving with respect to each other with a velocity V, there is no way to distinguish whether A is moving... | [
"A preliminary comment:",
"Relative motion has been known since Galileo's day. In fact, it's called Galilean relativity.",
"Here",
" is a recent thread that discusses the twin paradox."
] | [
"However, there is no way (according to (a.)) to identify which twin was moving away from the other.",
"Actually, there is, in the twin paradox. While there is no universal answer for which one is ",
", there ",
" a universal answer for which one is ",
". As it turns out, one of the twins (the younger one... | [
"Yes, Newton came well after Galileo and was aware of velocity addition."
] |
[
"How do aeroplane black boxes withstand crashes which otherwise destroy the plane and everything inside of it?"
] | [
false
] | I get that they are built to a higher specification, but not how that is achieved. | [
"Flight recorders are usually built with a compound casing of aluminium, steel and insulating material that can protect the electronics from high Impact and extrem temperatures. Compared to that aircrafts are built with the lightest possible materials, like alumium-carbon alloys. They can withstand the pressure of ... | [
"Kind of unrelated but reminds of of the Warthog. Only plane designed to get shot at.",
"https://en.wikipedia.org/wiki/Fairchild_Republic_A-10_Thunderbolt_II",
"It has 540 kg of titanium armor. Designed to withstand hits from armor piercing rounds and high-explosive projectiles.",
"",
"",
""
] | [
"An airplane made out of blackbox material wouldnt be able to fly very far.",
"That's an understatement. An aircraft built to withstand a crash would need engines the size of the Space Shuttle engines to even get off the ground."
] |
[
"How much warning would be have before an asteroid strike."
] | [
false
] | I mean would we have enough time to teach some oil rig workers to be astronauts? No but seriously how long before we could say that a NEO had say an over 90% likelihood off colliding with earth? | [
"Impossible to say. Depends entirely on how big the object is and whether we were lucky enough to look in the right direction when it's coming.",
"Independent of size, in the worst case you'd have roughly one second from when it enters the atmosphere and lights up to when it strikes the ground.",
"If it's relat... | [
"Hmm my understanding of cosmic science is that it's all completely predictable and easy to model (ie eclipses transits etc) what is it that stops us tracking and predicting the movements of these objects is it just lack of data and processing power or something more interesting?"
] | [
"Short answer: There are just too freaking many of them, and of all but a (relative) handful, we don't know where they are and where they're headed.",
"Long answer:",
"If you have two masses orbiting each other, their behavior is completely predictable. ",
"With three or more objects",
" there is no longer ... |
[
"What happens to Oceanic crust once it passes the Moho during subduction?"
] | [
false
] | In many of my upper level Geology classes, the professor can not answer the question. Nobody knows exactly what happens to the crust, whether it eventually all melts and diffuses into the mantle or if it makes it all the way to the outer core, to be melted there. Any thoughts? | [
"It certainly persists for quite a while, there is reasonable tomographic evidence of slabs extending well into the mantle. There are better examples I'm sure, but ",
"the image at the bottom of this page",
" has some tomographic results from across Japan and east of Australia where we can see a band of slow se... | [
"The important thing to remember is the differences in volumes, which we can see if we do a simple thought experiment. It's reasonably straightforward to do a back of the envelope calculation to calculate the amount of mantle that would be lost over time. We would need to know the volumetric rate of crust oceanic c... | [
"The question is are they completely recycled back into the mantle (and eventually new oceanic crust) or is there residue of slabs that never gets reincorporated?",
"If mantle is consumed to form new crust, but not all crust is recycled to form new mantle... This seems like an imbalance with huge long-term conseq... |
[
"If I drink, say, a mole of water molecules from a public source of water, is it likely that I ingest at least one atom of every stable element on the periodic table?"
] | [
false
] | null | [
"The short answer, YES. By a large margin.",
"In fact, the mole is such an extremely large number that you are likely to ingest millions of atoms of every element, even for the rarest elements.",
"Rough estimate: Osmium is the rarest element, at atomic abundance of 10",
" in the earth's crust. Mole is approxi... | [
"You are mistaken. The mole is such an extremely large number that the presence of at least one atom of any stable element is all but guarantied.",
"Also, at extreme dilutions we are talking about the presence of any poisonous elements won't be noticeable. It will have absolutely no noticeable effect in the body.... | [
"You are mistaken. The mole is such an extremely large number that the presence of at least one atom of any stable element is all but guarantied.",
"Also, at extreme dilutions we are talking about the presence of any poisonous elements won't be noticeable. It will have absolutely no noticeable effect in the body.... |
[
"Are there theoretical types stars that haven't been discovered yet?"
] | [
false
] | I found myself on the Pulsar wikipedia page, and it got me thinking that a type of star might exist for any astronomical concept we could think of. Are there any ideas out there about finding new stars that people are actively trying out that defy our conventional wisdom on the subject? | [
"Black dwarves, which are white dwarves that have cooled off over a very long time (longer than the universe has existed), are an example."
] | [
"We still haven't observed any Population III stars, so I suppose they count. They're, counter to the name, the oldest generation of stars, occurring in the first few hundred million years after the Big Bang. Consensus is that they were all huge in mass, with a very large range of possible masses (I've seen models ... | [
"We're not quite sure yet (you're basically asking if quark stars can exist or not, I assume). The main reason that quark stars were hypothesised is the fact that there's a sizeable gap between the highest-mass neutron stars that we've observed, and the lowest-mass black holes (observed neutron stars are between a... |
[
"Why don't we remember the beginning of our lives?"
] | [
false
] | Most people cannot remmber being younger than 3-4 years old, is there anyone who can remember acuratly the very early stages of their lives?, EG 1st birthday. I am not asking about the extremes of why we don't remember being in the womb ECT, but why dont we remember being younger than about 3-4? | [
"From the ",
"wikipedia",
" article that is actually pretty good:",
"Two key structures in the neuroanatomy of memory, the hippocampus and prefrontal cortex, do not develop into mature structures until the age of three or four years. These structures are known to be associated with the formation of autobiogra... | [
"It's a weird effect called \"Infantile Amnesia\", or ",
"\"Childhood Amnesia\"",
".",
"Which, not too long ago was so wildly misconstrued in both AskReddit and AskScience I wanted to karate chop everyone. That term does not mean \"one day I woke up and BAM I couldn't remember my childhood!\".",
"What it me... | [
"How is language learned and remembered differently than autobiographical memories?"
] |
[
"I never did understand... the difference between accuracy, precision, reliability and validity?"
] | [
false
] | [deleted] | [
"Did you read these?",
"http://celebrating200years.noaa.gov/magazine/tct/accuracy_vs_precision_556.jpg",
"http://en.wikipedia.org/wiki/Accuracy_and_precision",
"Accuracy: closeness of a measurement to its actual value",
"\nPrecision: closeness of repeated measurements to each other"
] | [
"In other words:",
"More specific = less chance of a false positive",
"more sensitive = less chance of false negative",
"right?"
] | [
"my favorite visual metaphor for accuracy vs precision is a dart board.",
"\nAssuming you are aiming at the bullseye, you throw three darts. High accuracy, low precision: darts are widely spread, but the center of the spread is the bullseye. Low accuracy, high precision, the darts have a very small spread but a... |
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