title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"What is the maximum amount of hours you can spend in the same date?"
] | [
false
] | If you could travel fast enough. What is the maximum amount of hours one could spend on a specific date? Say i went 24 hours in one time zone, then had the speed to go to the edge of the next on and repeat as many times as possible to stay in today. | [
"The time zones go from UTC -12:00 to UTC +14:00, as can be seen on ",
"Wikipedia",
". That alone is enough for a 50 hour day. You could get an extra hour if the Line Islands used daylight savings time, but it seems they don't. You don't have to go that fast for this. You basically just have to cross the intern... | [
"Stupidly pedantic, but +1 second if you pick a leap second day to do it on."
] | [
"Theoretically I believe 47:59:59 hours:minutes:seconds. It's all based on the international date line. If you view a world map and image it is segmented into 24 equal time zones. You could travel through all of those zones and then back around to the international date line theoretically getting you back to the st... |
[
"How likely is it that there are undiscovered elements in different parts of the universe?"
] | [
false
] | null | [
"Despite its name, the island of stability isn't theorized to be stable. It is just theorized as less unstable than other nearby elements."
] | [
"We can create those heavier elements artificially in the lab and they may form spontaneously in the high-gravity, energy-rich centers of stars, but they don't last. Their nuclei are too large for the nuclear forces to hold them together, so they're highly unstable."
] | [
"That's the thing about the periodic table of elements. It tells us what elements are possible based on their structure. Since there are no \"holes\", we know we're not missing anything.",
"That's not to say that we can't find heavier elements, which scientists are continually working to create in the lab, or o... |
[
"Question about zero voltage"
] | [
false
] | Say you have a circuit. At a point where the voltage is zero, does that mean there is no difference in potential between that point and the ground? Could you touch that 0V point and not get shocked even though there is current flowing through it? Does AC or DC make a difference? | [
"Voltage is the potential difference between 2 points. If you make one reference point ground and some other test point not ground and the potential is zero then current will not flow because there is no motive force. AC is a different beast. If neither side is grounded current won't flow to ground. ",
"Edit: to ... | [
"First, voltage \"at a point\" is an invalid statement. Assuming you mean ground as a reference point and voltage to groung is 0V it means this point is effectively ground. If you would insert yourself between ground and this point, no current would flow through you, therefore no shock."
] | [
"I would take issue with calling it effectively ground, because a floating point that has the potential of ground will not sink and source current the way ground does."
] |
[
"Can your body adapt to hot temperatures over time like exercising a muscle increases it’s strength?"
] | [
false
] | null | [
"Yes, ",
"\"These physiological adaptations include:",
"To acclimatize workers, gradually increase their exposure time in hot environmental conditions over a 7-14 day period. New workers will need more time to acclimatize than workers who have already had some exposure.\"",
"https://www.cdc.gov/niosh/topics/h... | [
"Additionally, some people are genetically predisposed to be able to handle heat better. As far as I am aware, it's mostly through anthropometric characteristics (IE how your body is shaped). Your body dissipates heat through your skin so if you are tall, lanky, and skinny, you'll have more surface area per lb of b... | [
"Yes as someone who worked in an industrial forge you do adapt to hot temps over time.",
"My first summer I had several bouts of heat exhaustion and overall had high heat stress all summer. ",
"By my last year there (7 years) summers were more of an annoyance than a possibly deadly situation.",
"Average temp ... |
[
"Why shouldn't you extinguish a beach bonfire by burying the fire with sand?"
] | [
false
] | null | [
"In terms of intrinsic properties, sand has a decently high heat capacity and a rather low thermal conductivity. The former property means that sand can absorb a large amount of thermal energy and the latter means that hot buried sand can retain this energy for a prolonged period. In practical terms, this means tha... | [
"sand is such a good insulator in fact that some cultural foods involve cooking large pieces of meat by burying the meat and coals underneath sand and cooking for hours."
] | [
"Burying the fire may smother it, but you have a lot of hot coals now insulated by sand. You risk something flammable which comes in contact with the sand or with the material lighting on fire long after you've left. Similarly, this is a bad idea if you expect anyone may be on that beach in the next day or so. They... |
[
"There were once less than 30 California Condors left. How does this affect the species, genetically?"
] | [
false
] | All future California Condors will necessarily originate from those few. Is there enough generic diversity with those 30 subjects for the species to recover and thrive? | [
"Yes actually! There were three distinct families that were left over and when breeding programs were started they made sure to breed condors to those who were least like them. Condors were transfered between breeding facilities on a regular basis and the condors that are alive now have the broadest \"range\" of ... | [
"This is a concept called ",
"\"Genetic Bottleneck\"",
". If the limited number of surviving members of the population happen to have genes that made them more likely to survive the bottleneck in the first place, the population as a whole may become heartier. But if the bottleneck resulted in a small population... | [
"20,000 and 30 are very different numbers when you're trying to assess the genetic diversity of a species."
] |
[
"How much longer will the Hubble Space Telescope remain operational?"
] | [
false
] | How much longer will the Hubble Space Telescope likely remain operational given it was launched in 1990 and was last serviced in 2009,9 years ago? | [
"BFR could potentially bring it back in one piece with an acceptable cost.",
"I really hope they do this. Hubble was such a revolutionary instrument, it should be in the Smithsonian, not charred scrap at the bottom of the ocean."
] | [
"As long as NASA finds a way to use it. They are expecting that it will fall back to Earth ",
"between 2030 and 2040",
". It could fail due to other issues before, of course. ",
"BFR",
" could potentially bring it back in one piece with an acceptable cost."
] | [
"A good resource is ",
"this Hubble Status presentation PDF from 2017.",
"The HST's most vulnerable component is its gyroscopes, which are used for precisely pointing the telescope. It needs three gyroscopes for normal operations, and it has six on-board for redundancy. ",
"The second gyro of those six fail... |
[
"Is the future of Internet speed more closely in line with hardware or software advancements?"
] | [
false
] | I'm not very knowledgeable with technology, so forgive this question if it's stupid. I'm aware that advancements in hardware allow us to send information at incredible speeds through the series of tubes that is the Internet. My question is, will future speed increases be based upon advancements in the materials and ph... | [
"Its primarily in line with business decisions than technological decisions"
] | [
"This is pretty much the best answer. If you have the money the sky is the limit in terms of raw throughput. Throw enough cash at a teir-1/teir-2 provider and you can have your very own dedicated multi-fiber bundle that basically guarantees you will saturate the connection of whomever you're communicating with be... | [
"I am currently working for an internet provider that is make a shift to faster internet speeds. They are doing it in two major ways. This company supplies TV and Internet which share the same cables. Until recently we still offered analog cabler service. Analog uses wave signals were as digital uses binary and... |
[
"What really kills you when you die of thirst or hunger?"
] | [
false
] | null | [
"For starvation, you first run out of carbohydrates (sugars) as an energy source, then you run out of lipids (fat) as an energy source, and finally your body starts breaking down proteins for energy. Since proteins are essential to all your cellular function, this means that your body starts breaking down your orga... | [
"Yes. That is one of (not the only) the biological/evolutionary reasons that our bodies tend to store excess food as fat. As a battery for scarce times."
] | [
"Does this mean that if you are twice as fat as person A (by % of fat in the body) does that mean you would live twice as long without food (with normal access to water)?"
] |
[
"What are the differences between Antimatter and Matter?"
] | [
false
] | null | [
"From ",
"the Wikipedia page",
":",
"antimatter is material composed of antiparticles, which have the same mass as particles of ordinary matter but have opposite charge and quantum spin.",
"Normal matter is made of Neutrons (with a neutral charge), Protons (with a positive charge), and Electrons (with a neg... | [
"The quarks and anti quarks would annihilate and anything that doesn't will hadronize. This would still be a very energetic event."
] | [
"What do you mean by \"combine\"? Does that mean low speed physical contact? High speed accelerator?",
"How is it stored? How is it transported from wherever it is made to wherever it is stored?"
] |
[
"I know that through evolution one species can become another species, but at what point does one species turn into another?"
] | [
false
] | I also don’t know what flair to put, so I put chemistry | [
"It's a new species when people agree that it's a new species. ",
"There's no dividing line, because \"species\" is just a human definition that doesn't line neatly up with biology. There are many different definitions of \"species -- the one that's most widely known is the ",
"\"biological species concept\"",
... | [
"Some conditions apply, your results may very.",
"Animals can be different species and still produce fertile offspring, mostly ones that are geographically seperate."
] | [
"There isn't really a single point you'd be able to identify where the species changed. With a few exceptions, like ",
"polyploid speciation",
" in plants which can theoretically happen in a single generation, speciation is a continuous process that takes some time. Many people make a distinction between two ... |
[
"So if you cannot create or destroy energy, does that mean there's a constant amount if energy in the universe?"
] | [
false
] | null | [
"Sort of but not really.",
"To keep a long story short, the law of conservation of energy only applies for any system which is \"time-translation invariant\" -- meaning, if you did an experiment, the time you choose to do the experiment would have no effect on the outcome. For any system that is time-translation... | [
"True, although whether the universe is infinite or not, you can still write conservation of energy for a small volume by saying any change in the amount of energy in the volume must be due to energy leaving or entering the volume through its edges."
] | [
"Oh yeah, no doubt about that. :) Though the OP was asking about the universe as a whole, and not a small volume of it -- so that's the question I answered. :p"
] |
[
"What defines male and female in a Seahorse?"
] | [
false
] | I have been told many times that with seahorses, the males hold the fertilized eggs and give birth to the offspring. But doesn't that make them the female? So what makes them male? Is it a Y chromosome? Is it the difference between sperm and eggs? | [
"Females have the ova (eggs). Males have the sperm. For some reason, in seahorses, the females insert their eggs into the male and he fertilizes them inside himself. After gestation, all the hundreds of babies burst out.",
"Biological life is weird, haha."
] | [
"Seahorses just don’t care about our arbitrary concepts of gender and sex. ",
"To a seahorse, the only thing that matters is who’s making sperm (male), and who’s making eggs (female). The idea that the one who carries them, or the one who gives birth, is a specific gender or sex doesn’t matter to a seahorse. ",
... | [
"The larger of the two gametes is the ova. The smaller is the sperm. Same size gametes get arbitrarily assigned. "
] |
[
"Why is there so much controversy surrounding GMOs?"
] | [
false
] | I just don't understand it. I work in molecular biology/biophysics. Although I don't do any work on food production, it seems common sense that we would want to genetically modify our food to produce the traits we want, and not the ones we don't. This seems like a no-brainer. So why is there so much controversy over GM... | [
"Are you asking what the controversy surrounding GMO ",
" is, or are you asking about GMOs broadly? To many people, the word GMO means food, but we really have engineered a whole bunch of organisms beyond just foods.",
"When I talk to people, the responses fall into one of the following categories, all paraphra... | [
"It seems to me that you are brushing off the last argument and painting it in a very non-scientific way when it can really be a legitimate argument. When you take away all the philosophical stuff, the actual argument goes something like this (using corn as an example):",
"If we completely monoculture corn acros... | [
"Its not a scientific question really because the reasons are mostly political.\nThe #1 pusher for GMOs is ",
"monsanto",
" who have an incredibly bad name. They manufactured agent orange in vietnam and have a hand in manufacturing lots of food you buy in supermarkets.",
"They also have a practice of suing fa... |
[
"Breathing in high altitudes with compressed air?"
] | [
false
] | Hi all, The other day I was reading about mount Everest and how a bunch of dead bodies remain up there because no one have the strength to get them down from above 8.000 m. I know we breathe on high altitudes (inside airplanes) thanks to air compression. The oxygen don't diminish with higher altitude, only gets separ... | [
"To answer your question in parts,",
"1) Why use pure oxygen? This is because what matters is the partial pressure of oxygen. In the atmosphere, oxygen comprises roughly 20% oxygen. This means that you could breathe air at 20% of sea level pressure if it was 100% oxygen. So carrying oxygen to high-altitude enviro... | [
"Nevermind the compressing part, even if you had the energy to do it. Lungs work on a somewhat minute pressure gradient established by expanding the volume of the cavity in which they reside, thus causing a lower pressure within said cavity. As a result, air rushes in. Regardless of the altitude, this is going to h... | [
"Nevermind the compressing part, even if you had the energy to do it. Lungs work on a somewhat minute pressure gradient established by expanding the volume of the cavity in which they reside, thus causing a lower pressure within said cavity. As a result, air rushes in. Regardless of the altitude, this is going to h... |
[
"Could we find opportunity?"
] | [
false
] | null | [
"We know exactly where Curiosity is. The hard part is getting there."
] | [
"Planetary sci"
] | [
"Planetary sci"
] |
[
"The photons sent after the big bang must have bumped into millions of galaxies, stars, planets, ... If matter absorbs photons, how is it possible that we still see the cosmic background radiation?"
] | [
false
] | The main reason why I can't figure this out is because the universe expands faster than the speed of light. So all matter that came into existence somewhere in space, must have been there before the light from the big bang reaches it | [
"Most of it actually hasn't been absorbed or scattered significantly, because space is really mostly empty. However, a fraction of it is scattered as it passed through the hot ",
"intracluster medium",
" plasma around galaxy clusters. This results in a change in the spectrum of the light called the ",
"Suny... | [
"It's already incredibly dim, sitting at around 2.7 kelvin and will continue to cool, fade and become harder to detect that is correct. In about 10 to 100 billion years in fact it'd be impossible to tell the big bang happened. Any modern proof of the big bang becomes undetectable around those time frames. "
] | [
"The simple answer is: because they literally come from everywhere. ",
"They are the light that was bouncing about at the Big Bang, which happened everywhere that was, that light is from everywhere in the universe and has been bouncing around for 13.7 billion years. It ",
" get absorbed, but there is simply so ... |
[
"How does transparency work?"
] | [
false
] | As far as I can tell, there aren't little holes for the photons to jump through in my window. I'm curious to know the mechanism behind transmitting light through a transparent material in addition to the obvious case of how it gets through the air we breathe. | [
"So there are two different primary mechanisms for transparency.",
"1) Materials have what is called a \"bandgap\". In this bandgap, electrons in the material cannot have certain values of energy. That is, imagine a ball - you can give the ball any energy you want. But in a material, if you pretend the electrons ... | [
"I'm sorry but the 'little holes' description wholly misses the point. Your second description is more correct. ",
"Edit: While an electron can be localized to an incredibly \"small\" space, it is most certainly NOT ",
" a golf ball whizzing around in the context of an atomic structure. That's why the 'holes... | [
"There are three things you need to consider to understand transparency:",
"There is a property of matter called the index of refraction (yes, which can be derived from other physical quantities). This index describes how matter behaves when an electromagnetic wave such as light impinges on it. The index is gener... |
[
"Why do distorted, fuzzy lines appear when viewing a computer screen through a phone camera?"
] | [
false
] | [deleted] | [
"You may also be thinking of the ",
"Moire pattern",
". This is because of something called ",
"aliasing",
" (this thing that video cards are anti). Because both the screen and the camera are made up of arrays of pixels, the differing alignments cause these patterns. If you increased the resolution of the c... | [
"Because both screens actually flicker with the ",
"refresh rate",
"Here",
" is a quite easy to understand article about it."
] | [
"I'd say that the phones screen refresh rate has little to do with it, its rather the difference between the cameras frame rate and timing, and the refresh rate of the screen, than that of the computer screen that does it.",
"Cameras are typically 30 fps while the screen refreshes at 60 Hz (60 fps). If they were... |
[
"What is the difference between cane and beet sugar?"
] | [
false
] | From what I understand, there is no way to distinguish cane sugar from beet sugar other than some small C4 vs C3 marker that is irrelevant nutritionaly. Yet, you see food packages that advertise "made with pure cane sugar" as if it's superior. | [
"A lot of those packages specify \"pure cane sugar\" to differentiate from high fructose corn syrup, which IS nutritionally different. ",
"That being said, packaging says whatever sells, and people like to think that cane sugar is somehow \"purer\". Same way that a lot of cereal mention that they're low in sodium... | [
"Also, I'd like to point out that even when comparing HFCS and cane sugar, the actual nutritional differences are very small. "
] | [
"Hmm is it that cane sugar is sometimes turned into char bone sugar vs beet sugar generally being organic and raw? I'm not sure tbh. But I know when I was looking into animal product-less sugar, that kept coming up on google. "
] |
[
"Are there any long term health threats from regular but low exposure to CO?"
] | [
false
] | null | [
"I could probably drag up the paper again if needs be, but there is a reported ",
"increased incidence",
" of aortic aneurysms in firefighters that is thought to have been caused by exposure to carbon monoxide.",
"Now, these days, firefighters use SCBA to minimize their exposure to smoke, so the study is quit... | [
"No it was more that my friends do it and i was checking out if the health risks were significant before like joining them. I know that low oxygen levels in the blood can cause brain damage what with brain cells inability to respire anaerobically and all, but I was wondering if the low levels (10-20 ppm) relatively... | [
"Even though RBC's have a short lifespan, body organs need oxygen constantly so there is the potential for some cellular damage.",
"\nBut if the CO levels are infrequent, then I doubt it's doing any more damage than walking alongside heavy traffic in a city would do. "
] |
[
"How do Jet engines work?"
] | [
false
] | I was reading about the internals of jet engines earlier and a diagram showed two small compressors behind a turbine, which then seems to put the compressed air in a combustion chamber, and after combustion it just chucks it back out again... surely pressurized air that's been combusted can't provide that much thrust? ... | [
"There are many different type of jet engine but simply put the purpose of the compressor is to suck in as much air as possible into the small space of the combustion chamber. You then combust the gas and it expands ",
". This expansion provides the thrust but also powers the turbine which connect the compressor ... | [
"I explain the basics of turbojets like a 4-stroke internal combustion engine in your car. ",
"See diagram.",
"First you have an intake: draw air into the engine, like the intake stroke in an IC engine.",
"Second you have compressors compressing the air, like the compression stroke in an IC engine.",
"Then ... | [
"Good question. Have you ever seen one of those jet sprinklers with nozzles that point in opposite directions? They spin once you put some water through because the nozzles are providing thrust.",
"The thrust force of a jet is equal to the rate of mass flowing out of the nozzle (kg/s) multiplied by the velocity o... |
[
"I found this big tooth washed up on the beach (Hilton Head Island, SC) on vacation last week. Does anyone know what it's from?"
] | [
false
] | I it's a tooth, though I could be wrong. edit: I think you guys have nailed it as coming from an Atlantic horseshoe crab (and not a tooth after all!) Very cool to know! Good chance it is likely a tail, it certainly smells like it was near something's asshole. | [
"Everyone, could we please keep this discussion civil and mature? This is a legitimate question that deserves a legitimate answer. Keep it scientific please. "
] | [
"Long enough rolling around in the sand because of waves motions will smooth out those serrated edges. ",
"The fact that the walls of this thing are so thin point to a chitinous exoskeleton. If you try to bend it, is it a little resistant but still bends a bit?"
] | [
"Long enough rolling around in the sand because of waves motions will smooth out those serrated edges. ",
"The fact that the walls of this thing are so thin point to a chitinous exoskeleton. If you try to bend it, is it a little resistant but still bends a bit?"
] |
[
"Does the auditory nerves activate, when we hear the voice of our thoughts?"
] | [
false
] | I was wondering whether the nerves that are firing when we process sound activated, when we "hear" sound in our mind. Same could be asked for visualizations. | [
"Higher order auditory and visual regions of the brain can get activated, but not really the primary auditory/ optic nerves. Those sort of need to funnel in physical stimuli (sound/ light stimuli), so they're not active if nothing is coming in. But they're connected to other regions via synapses that are involved i... | [
"I read something that said that they did an FMRI study for people with Schizophrenia and that the brain was activated in the same ways when hearing auditory hallucinations as when listening to someone else speak. However, it did not go further into if this is normal for anyone when \"listening\" to an internal voi... | [
"I read something that said that they did an FMRI study for people with Schizophrenia and that the brain was activated in the same ways when hearing auditory hallucinations as when listening to someone else speak. However, it did not go further into if this is normal for anyone when \"listening\" to an internal voi... |
[
"Why do dogs have a \"wet dog\" smell?"
] | [
false
] | I have had several dogs over the years and it does not matter what kind of fur they have they all have that same or similar smell that just stinks. What causes this? | [
"Dogs have sweat glands, just not for the purpose of thermoregulation. The distinct \"wet dog\" smell is from apocrine glands which are associated with every hair follicle on a dog. The purpose of these glands is to seal the outer layer of the skin (which is why it's an oily secretion) and also acts as a pheromone.... | [
"This is only a partial answer - it doesn't explain why a dry dog doesn't smell quite as a wet one does. The evaporation of water from the dog carries the smell. Most of the smells (the volatiles) are from bacterial decomposition of oil secreted by the apocrine glands as well as anything else the coat/skin has pi... | [
"Fun fact: Purebred huskies don't have that stinky dog smell."
] |
[
"If mRNA translation errors are relatively common, how do cells prevent malformed proteins from getting out of control?"
] | [
false
] | I read that one of the challenges with the mRNA COVID-19 vaccines is that mRNA breaks down pretty quickly. That made me curious what happens if a cell begins to translate mRNA that has already been partially degraded. While researching that I learned that translation errors are actually quite common. Presumably cells m... | [
"Cells have various mechanisms of correctly both transcription errors and translation errors by helper proteins. ",
"Even after translation it still has to fold correctly and possibly be modified further to be useful. ",
"Even if a bad one gets through which doesn’t work correctly, that doesn’t mean there aren’... | [
"There are various systems of control in the endoplasmatic reticulum and in the Golgi apparatus. Also, in the citoplasm I think. \nChaperon proteins control the protein multiple times and if it doesn’t fold properly it’s discarded.",
"Also, when mRNA breaks down it just can’t be used anymore, it’s like if you ha... | [
"They idea of for your own body to learn to recognize those spike proteins. ",
"After the exposure your body will generate antibodies to the antigens on the spike proteins. Those antibodies will stick around in your body. While they exist, you no longer need a source of spike proteins."
] |
[
"Whats the current scientific thought on how humans learn, and how to apply that to learn efficiently?"
] | [
false
] | null | [
"This is a very broad/vague question. You can take an entire semester-long college course on Learning. Do you have a more specific question?"
] | [
"Tackle what you personally think is most important about it",
"The issue with the science of learning as far as I can tell is just that; its broad, vague and not very cohesive. It's something everyone uses but there doesnt seem to be a discipline dedicated to it. I was hoping that someone could summarize the kno... | [
"This sub isn't really geared toward summarizing entire fields of study. It's like asking \"what happened in Europe in the 19th century?\" I recommend trying to narrow down to a more specific question. If you want a general understanding, you can try to find free pdfs of textbooks on human memory or learning. "
] |
[
"If you did drugs, then 'groundhog dayed' back a day, would you still be addicted?"
] | [
false
] | null | [
"Groundhounding a day back isn't a real thing so we can't answer this question. "
] | [
"The question is whether or not the memory of a drug's effect is enough to hook one on the drug, despite no physiological changes."
] | [
"What is a realistic scenario in which that could happen?"
] |
[
"Do we know of any micro-organisms that could possibly survive space travel via asteroid?"
] | [
false
] | A made it to the front page today that said that rocks thrown into space by the impact that killed the dinosaurs may have had enough force to get to Mars or Europa, potentially seeding them with life. It seems implausible that any micro-organism could possibly survive the varied conditions caused by the impact, prolong... | [
"I am not exactly qualified to answer this question, but I did read an article the other day regarding Tardigrades. From what I understand they are the closest microorganisms that humans know of that could survive each of those kinds of environments. Here's a link to more information about them. ",
"http://tar... | [
"A species of cyanobacteria survived in space for 553 days. So some of them can certainly survive in space. I believe they are unable to reproduce in space, however. Source below, apologize for it not being the best source.",
"http://news.discovery.com/space/record-breaking-microbial-star-trekkers.htm",
"I took... | [
"The trouble I see with tardigrades as they are described by that article is that while they can totally survive all of that stuff in their hibernation mode, they need water in order to wake up. Mars is pretty dry, but Europa may be a decent habitat for the little guys providing they're ok with an average temperatu... |
[
"If inflation inflates space, why doesn't it inflate the speed of light?"
] | [
false
] | I don't understand how stretching space would physically increase the subjective distance between two objects. Wouldn't the observer and the two objects increase in size too, as well as all particles, forces and natural constants, thus rendering the change invisible to the inner observer. | [
"That's kinda implied by the fact that we can measure the expansion. But isn't an inflation that ONLY affects the distance between objects not actually an inflation of space, but rather a simple relative movement of objects, thus it should not violate the speed of light ?"
] | [
"But isn't an inflation that ONLY affects the distance between objects not actually an inflation of space, but rather a simple relative movement of objects, thus it should not violate the speed of light ?",
"No, it actually is an inflation of space. From an inertial reference point they are not accelerating at al... | [
"Wouldn't the observer and the two objects increase in size too",
"The fundamental forces completely overpower the effect on a local scale, negating any tendency to become larger. Natural constants are unaffected."
] |
[
"What would happen, gravitationally, if the sun suddenly ceased to exist?"
] | [
false
] | null | [
"The problem - and I realize you might not know this - is that matter simply doesn't \"cease to exist.\" That is not permitted in relativity.",
"If you want to model it classically, then the Earth will continue in its inertial path. This means it will continue it's current velocity - Newton's first law.",
"If y... | [
"I understand that it is not a possible scenario, I just sought the answer to what would happen if this somehow were to occur."
] | [
"You're not getting my point. You're asking someone to disregard some law of physics, then analyze the scenario using the laws you just broke. That's why the set up is meaningless. However, often one forms these questions to understand some relationship in those laws, and I was attempting to figure out what you're ... |
[
"If you have an organ transplant, will your body gradually replace the DNA in it with your own, or will the cells continue to regenerate with the same external DNA?"
] | [
false
] | [deleted] | [
"By and large the transplanted tissue will retain the donor DNA. This fact should not be too surprising considering that you are taking a complex slab of tissue with millions of cells, which are not going to be readily replaced. From the point of view of these cells, they won't \"know\" that they are now in a forei... | [
"Can confirm, I also have had a Bone Marrow transplant. I now have two types of DNA. My blood DNA is that of my donor, however, my tissue DNA (such as skin etc) is all mine. Also interesting is I was O- prior to transplant but am now A+ due to the donors blood type. Pretty crazy stuff they can do these days. "
] | [
"I've had a bone marrow transplant. Does that mean if the police do a DNA test on my blood, I'll have the DNA of my donor? "
] |
[
"With the continued development of antibiotic resistant strains of bacterial infections (e.g. Gonorrhea currently heading toward superbug status) why does there seem to be so little pursuit of viral phage medicine?"
] | [
false
] | has been known about and established for some time primarily in Eastern European countries and yet there seems to be very little talk about it outside of those areas. Is there some prominent issue preventing a heightened development of this type of medicine? Edit: gives a good overview about phage therapy and its histo... | [
"First a history lesson: Phage therapy was pioneered by the Soviets and Eastern European countries. However, in the West they heavily favored antibiotics. Antibiotics are broad spectrum, require no need for specific identification of the organism and are cheap. Phages are expensive, narrow spectrum and require spec... | [
"Bacteriophages are ",
" specific. Most anti-biotics are broad spectrum. This means we not only need to swab and confirm species and genus of infection, but then identify the strain, and provide the appropriate phage for that strain. These would be susceptbile over time to the same mutations that protect bacte... | [
"There's also risk that the virus could evolve and itself become a pathogen",
"Unless you have a citation, then I am going to say that is certainly not true at all. Phages have co-evolved with bacteria likely since the origin of cellular life and have highly specific receptors for attachment and entry. Phage jump... |
[
"If the moon fell to Earth, what would happen to the ocean as it was falling? Like what would happen to the tides as the moon got closer?"
] | [
false
] | null | [
"Such hypothetical / speculative / open-ended questions are better suited for our sister-sub ",
"/r/asksciencediscussion",
". Please post there instead."
] | [
"Okay sure! Should I delete this or leave it up?"
] | [
"Already removed"
] |
[
"How much are the personality traits of alcoholics caused by alcohol?"
] | [
false
] | Mid and late stage alcoholics are often described as being self-centered, grandiose, manipulative, self-pitying, anxious, easily frustrated, impulsive, dependent, and more. Is this correct? If not, I would still like to know which of their character traits can be said to be caused by alcohol alone? How does alcohol abu... | [
"Alcoholism is also comorbid with anxiety, depression, antisocial personality disorder, personality disorders, and a type of dementia known as ",
"Korsakoff's syndrome",
". All of these may affect personality presentations, and may be related to frontal lobe pathology, which is ",
"strongly correlated with al... | [
"Thank you very much for these links. The article ",
"FRONTAL LOBE CHANGES IN ALCOHOLISM: A REVIEW OF THE LITERATURE",
" had the information I had been looking for.",
"While I have you attention, do you know of any reliable estimate for the percentage of alcoholics in any given population? I know the answer t... | [
"This behavior is typical of addicts in general, and results from the addiction rather than the direct affects of the drug.",
"So yes and no.",
"http://en.wikipedia.org/wiki/Substance_use_disorder",
"\n",
"http://en.wikipedia.org/wiki/Substance_dependence"
] |
[
"Why can't we stimulate tooth growth, and why can't teeth repair after being damaged?"
] | [
false
] | [deleted] | [
"This comment has been overwritten by an open source script to protect this user's privacy. ",
"If you would like to do the same, add the browser extension ",
"GreaseMonkey",
" to Firefox and add ",
"this open source script",
". ",
"Then simply click on your username on Reddit, go to the comments tab,... | [
"So how does the common man go about having the ultrasound treatment?"
] | [
"I was talking with my dental hygienist yesterday, and he mentioned that there was a study done, where they took stem cells from the bone marrow and induced bone formation 90% of the time. I'm having the hardest time finding the study, but I guess it's possible ",
" ",
"This",
" is the closest I've gotten!",
... |
[
"What are the potentials of Antarctica?"
] | [
false
] | I hadn't realized that Antarctica was once warm and temperate. There could be tons of fossils there. We've used it to study the level of carbon in the Earth, but imagine if we could look deeper? The continent also has an ancient lake (Vostok), which could still have extremophile bacteria / viruses and organisms. Openin... | [
"It is one of the best places on earth to collect meteorites. Basically any rock sitting on the ice has a high chance of being a meteorite so every year teams go there to collect them."
] | [
"Opening it could contaminate the lake, or the earth.",
"Maybe the lake, but not the earth. The extremophile bacteria would be easily outcompeted by ordinary bacteria (who don't have to spend energy supporting all the bells and whistles that the extremophiles use to survive in harsh conditions)."
] | [
"Aww, I guess that X-Files episode will never become a reality :)."
] |
[
"On a wave level, what is the difference between two sounds that are identical except for their timbre?"
] | [
false
] | null | [
"Well, if the timbre is defined as the sound when pitch and loudness are equal ",
"http://en.m.wikipedia.org/wiki/Timbre",
", then it must be the frequency content that differs.\nThe instruments do not play only one frequency per note. They play a note and range of harmonica of that note defined by the shape a... | [
"A sound source is a structure that for some reason is going through mechanical vibrations. Air going through the pipes and holes of a wind instrument, a bow or a pick vibrating a string, a stick hitting a drum. These vibrations excite the elastic medium through which sound propagates (air in most cases) which then... | [
"Not OP, but follow-up question:",
"The elements you mentioned, if I understand correctly, are basically the harmonics (over- and under-tones) that accompany the main tone. As a guy who started his music composition and programming on a C-64's SID chip, I became very familiar with the concept of the ADSR sound en... |
[
"What happens when the speed of expansion of the universe passes c?"
] | [
false
] | Well I guess the first question would be, can this happen? The expansion of the universe is accelerating, so do we know what would happen when it accelerates to the speed of light? What about faster than that? Isn't it impossible for anything to go faster than light? Also, if that happened, would we at one point not be... | [
"The expansion of the universe and the speed of light have different units, therefore you can't compare them.",
"The Hubble Constant is the fraction by which a given parcel of space will grow in a given amount of time. It has units of inverse time, s",
". The speed of light, of course, has units of distance/tim... | [
"We in fact know that far-away parts of the universe are receding from us faster than the speed of light. However, this is not a problem. It's better to think about the expansion of the universe as an change in space itself rather than the motion of the things in that space; think of it as extra distance appearing ... | [
"That dark and dismal scenario is called a ",
"big rip",
".",
"The really fun part will be when the acceleration becomes great enough to pull atoms apart. This could happen as soon as ",
"16.7 billion years",
" in the future. How dark energy works and how strong it is are a bit uncertain though, so there ... |
[
"Why is it that armpit sweat smells different than foot sweat, and that smells different from ballsack sweat? How are these different musks produced?"
] | [
false
] | See title. | [
"Sweat is odorless. Body odor is produced by bacteria that break down the sweat (basically bacteria poop). ",
"There are different bacteria on different parts of your body and they produce different smells.",
"One recent study published in the journal Science found that at least 18 different phyla of bacteria ... | [
"This sounds like a take-home experiment. Let us know the results, and thanks for volunteering! ;P"
] | [
"Ok, legit question; if one is having smelly/sweaty armpits and a clean ballsack then rubs his hand (or something sufficient) under his armpits and then rubs his sweaty/smelly hand on his ballsack, "
] |
[
"Is there any evidence that a caloric deficit doesn't help some percentage of the population lose weight?"
] | [
false
] | Specifically, what individuals cannot lose weight through a simple caloric calculation and restriction? What factors influence success through this specific medium? Hormones, genes, age? | [
"This would be physically impossible. If your calories in are less than you calories out, and you don't lose weight over time, one or both of these values has been mis-measured. Anything else would literally violate the laws of thermodynamics. Not to mention conservation of matter.",
"Hormones and genes and ag... | [
"There are people who get fatter despite calorically negative diets because their body actually cannibalizes their organs and muscles to produce fat. If they don't change their diet they starve to death. Of course, they are still losing weight. ",
"Source: ",
"http://video.google.com/videoplay?docid=43620414876... | [
"I don't think it's necessarily true that it never goes back to normal; some research has shown that continuing a vigorous exercise regimen (at least an hour of moderate exercise a day, 5-7 days a week) for over a year will help your body adjust to its new weight. You can lose weight without ever exercising beyond ... |
[
"Question from r/loseit - do fat cells go away when you diet or just shrink?"
] | [
false
] | null | [
"Shrink"
] | [
"That's actually not true. When you gain a lot of weight, you exhibit both an increase in the size of fat cells as well as the number of them (your body releases certain chemicals to stimulate the production of more fat cells). Unfortunately, diet and exercise will only shrink the fat cells, but not reduce their ... | [
"I'm thinking of this in a normal body working out type persepctive. What exactly is meant by 'a lot of weight'?",
"are we talking about 20 points, or more like 200?"
] |
[
"Is \"quantum probability\" the same as \"real probability\"?"
] | [
false
] | If I roll a die, as it's rolling, there's a probability if it being a 6 (1/6). This isn't actually whats happening, because we can theoretically analyze the conditions of the roll to determine the result before it stops rolling. Just when I roll it, im not perfectly examining it, so there's a probability. If I set up a... | [
"This is actually exactly the right question in a certain sense. There IS actually a difference between classical and quantum probability.",
"Classically, events have a probability of happening that is a real number between 0 and 1. If we add together the probability of every possible event, we should get 1 ( th... | [
"I just want to say that people like you and the effort you just put into this post is what makes Reddit an enjoyable place to be. Have an awesome day. "
] | [
"The answer is up to (some) debate, but most physicists would say it's truly unknowable. Theories that say there's more info we just haven't found yet are called hidden variable theories. ",
"Not exactly. Even proponents of hidden variable theories will tell you it's unknowable. While it's not truly random, the i... |
[
"Could someone help explain the second law of thermodynamics to me? What is disorder?"
] | [
false
] | I've read about the second law of thermodynamics a lot, and it seems to pop up in all sorts of places, especially discussions of the flow of time. But I just don't understand how it works on a conceptual level. My understanding (so far) is that everything in the Universe tends toward disorder. That's why you can't have... | [
"I have studied general relativity, quantum mechanics, quantum field theory, the theories describing black holes and Big Bang cosmology, and I have never in my life struggled with a concept as long and as frustratingly as I've struggled with entropy.",
"I'm sure someone else will come along and define the concept... | [
"I know next to nothing about mathematics or anything beyond high school physics, so my apologies in advance if this is a waste of y'all's time, ",
", how does the second law of thermodynamics--loosening arrangements of microstates in a system--figure with the picture we have of the expansion of the universe, whe... | [
"When it's said that the average temperature of the universe is three degrees Kelvin, that means the universe is filled with radiation corresponding to what would be emitted by an ideal black body with a temperature of three degrees Kelvin.",
"Was that your question?"
] |
[
"if only mass-energy consenves, does that means energy balances in engineering are wrong?"
] | [
false
] | if so, what other property should i balance in my sytems in order to keep degrees of freedom at 0, because if that is wrong, my momentum balances are wrong too, what are the properties that can be balanced? | [
"In all but the most extreme of cases, your energy balances are just fine. It's true that technically it's mass-energy which is conserved, but most systems especially in engineering do not experience significant mass changes--any changes that would be present, say from heating or chemical reactions are much ",
" ... | [
"Well, technically, even energy is not conserved since the universe is expending.",
"According to Noether's Theorem, conservation is linked to symmetry, which expansion breaks."
] | [
"Well, technically, even energy is not conserved since the universe is expending.",
"Energy is not conserved under certain contexts. All space outwards to the galaxies in our local group are ",
" experiencing expansion from each other. So if you're figuring out the energies involved in constructing a building, ... |
[
"Why am I (with an AB+) blood type a universal blood recipient, but a universal plasma donor?"
] | [
false
] | I do understand antigens and why I am a universal recipient, but I just came across something on the red cross website that indicates I'm a universal plasma donor. | [
"Antibodies in blood plasma are the opposite of the blood type, so if you have type A blood your plasma has type B antibodies and vice versa. If you have type AB blood, though, your plasma has ",
" antibodies and can be safely given to anybody."
] | [
"your antibodies are created to attack foreign cells. if your RBCs are A, then your antibodies will attack the foreign B cells, and vice versa, to prevent contamination. If you are type AB, you can't have antibodies against either of those sets of proteins, or else you'll attack your own RBCs, which is not evolutio... | [
"Furthermore, if you have type O, your own RBCs have no antigens to recognize, so you safely produce antibodies against both A and B RBCs."
] |
[
"How do rovers such as curiosity maneuver in space?"
] | [
false
] | I would expect internal combustion rockets to be out of the question since they need both heat and oxygen to work. How would rovers adjust their flight path in space? | [
"As an example, the launch vehicle for the Opportunity Rover was a ",
"Delta II Rocket",
". The rover is actually a payload in the rocket - so the standard rocket motors are used to launch and maneuver. ",
"The fuel depends on which stage/booster it is and the actual Delta II model - but most of them appear ... | [
"I was looking for more on how they actually change course once in space. After I did some searching on the best search engine in existence, I came across some pretty satisfying answers. ",
"Resistojet",
"\n",
"Reaction Wheel"
] | [
"Though I'm not completely certain, I expect the system to be much like adjusting the orbit of the International Space Station. It's a combination of gyroscope flywheels like you mentioned, and rocket thrusters needed for more immediate and drastic changes.",
"The course taken by the vehicle containing said rover... |
[
"Why does the shadowed part of the moon appear to be invisible even during the day? Wouldn't we see some faint part of it?"
] | [
false
] | null | [
"If you look closely at the moon at night, you may be able to see the circle be completed by a faint glow. That is earthshine -- sunlight that has bounced off the earth, illuminating the shadowed (night) side of the moon. ",
"During the day, however, our atmosphere scatters so much blue light at us that it all bu... | [
"Yes, it's most visible on a small crescent Moon because at that point in the Moon's orbit, the Earth is nearly full from the Moon's perspective."
] | [
"Doesn't earthshine particularly visible at dawn and dusk, when the light reflected from the illuminated part of the Earth lights the Moon, and the brightness of the sky is not sufficient to fade it ?"
] |
[
"Mercury's orbit with the Sun?"
] | [
false
] | I was reading on wikipedia that Mercury is tidally locked with the sun with a 3:2 ratio. Meaning it rotates 3 times on its axis for every 2 rotations around the sun. But then it says that 1 day on Mercury is equal to 2 Mercury years. Wouldn't that be a 1:2 ratio. If someone could clarify this to me thank you. | [
"Okay. The planet spins at such a speed that its Prime Meridian passes the sun once every two years. In order to do that, the planet has to be spinning in such a way that the sun appears to set in the direction of planetary travel. A minor, but important distinction.",
"As the planet goes around the sun, it makes... | [
"There are two ways to measure rotation, one based on the local star (what we normally consider as a rotation) and one based on the galactic center (basically a lot closer to the absolute motion of the planet).",
"Imagine the planet for a moment, and assume it does not spin at all. Under the first idea, looking a... | [
"I'm still having a hard time picturing this. What do you mean when you say 2 years makes 3 rotations in space to complete one day. Wouldn't that be three days.\nIs it spinning on it's axis at a rate just slightly faster than it orbits the sun so the day just lasts really long?\nIs there any simulator where I could... |
[
"Would a hot dish of food have significantly more energy/calories if eaten than the same dish served cold?"
] | [
false
] | null | [
"It has more calories in the sense that hot things have more energy than cold ones. But it wouldn't have more usable calories. Not directly at least since the body cannot directly convert heat into a usable calorie source for metabolic action.",
"Indirectly though it might give us a little more energy. When you e... | [
"Eat the soup at room temperature; keep the stove and fuel handy to melt snow for water--a much bigger worry than food during the winter."
] | [
"Most foods have specific heats around 0.6 to 0.8 kcal/kg*C. A steak has around 2000 kcals/kg in chemical energy. If we look at a +40C change in temperature (reasonable), we're looking at 26 kcal/kg (for steak).",
"That's 1.3% more energy, which I'd say counts as \"not significant.\" ",
"That's neglecting any... |
[
"What keeps electrons in \"orbit\" (lazy, inaccurate word) around a nucleus?"
] | [
false
] | I realize that electrons actually exist in s, p, d, and f orbitals, and that these orbitals are not actually newtonian orbits, but rather areas of space around a nucleus that an electron is statistically likely to reside in at any given moment in time. In a newtonian orbit, such as the moon around the earth, say, what ... | [
"Just wanted to say thanks for this explanation! It's the best I've heard for describing the Hamiltonian in a concise way while still explaining the mathematical concepts behind it."
] | [
"lets take a look at the wave equation and compare it to the old school for the case of hydrogen with one electron and one proton. First the old school charge equation...",
"F=K",
"(charge of the proton)/r",
"F= force pulling the electron and proton together\nK=random constant\nr= distance between the proton... | [
"Perfect! I haven't encountered the Hamiltonian in my chemistry or physics classes yet. I just figured there had to be ",
". Thanks much. Quantum weirdness strikes again :D"
] |
[
"Will my stove always reach the same end temperature - only slower on a low setting?"
] | [
false
] | This may be a somewhat stupid question. I'm supplying heat over time by turning my stove on, correct? If I did this with a high setting on my stove and then later with a low setting but for a longer period of time, wouldn't the total amount of heat be the same? How would that work with regard to temperature? | [
"Short answer: no. The key point is that energy is leaving the burner/food system as well. The hotter the food/burner is, the faster it loses energy. To maintain a high temperature, then, you have to add energy in faster. So a \"high\" setting ",
" have a higher equilibrium temperature than the \"low\" setting. Y... | [
"I assure you I do not. The taps in your bathroom associate cold with blue for reasons that have nothing to do with thermal radiation. Hotter objects produce a spectrum that peaks at shorter wavelengths (bluer). "
] | [
"The question specifically asked about \"end temperatures\". The only physically meaningful interpretation of that is \"equilibrium temperature\". Otherwise, it's just whatever the temperature has reached when you turn the element off. "
] |
[
"How do objects leaving Earth overcome their rotational momentum due to the Earth's rotation?"
] | [
false
] | I couldn't find the answer on google because I can't really phrase my question right. This started with me thinking about what if the Earth stopped rotating? Everything would be thrown in a certain direction due to the momentum from the rotating Earth... But what about rockets for example? While they are within the atm... | [
"For things to orbit, they have to be going much, much faster than the rotation of the Earth. At the equator the tangential velocity of the Earth is about 150 m/s, whereas a low orbit requires about 7 km/s. So really, they have the opposite problem. Spaceships tend to be launched Eastward from a location close to t... | [
"The speed required for orbit decreases as the radius of the orbit gets larger.",
"Orbital velocity isn't the same as escape velocity; it's about 71% as fast."
] | [
"Thank you! I see now that the momentum is constructive to spaceships."
] |
[
"Are there any common transparent substances with a high dependence of index of refraction on temperature?"
] | [
false
] | And where would I find this kind of information? I can only find a few examples online of dn/dT (eg near room temperature water and mineral oil are around 10 / K at 633 nm, fused silica around 10 / K at 633 nm). I'm curious if there are any above 10 / K in the visible range. | [
"Are you OK with a phase change?"
] | [
"dn/dT is called the thermo-optic coefficient.",
"Here's a ",
"whole book",
" about these coefficients in optical materials."
] | [
"No, I'm contributing to some undergraduate labs and I was curious if I could have them measure the temperature of a substance through the index of refraction, so I was looking for a substance where the effect would be large (but I think a phase change would be too obvious an effect). "
] |
[
"Why are faces easier to scan than words?"
] | [
true
] | [deleted] | [
"There is a brain region dedicated to facial-feature recognition (fusiform gyrus in the inferior temporal lobe [usually right hemisphere]). Even infants can discriminate between [upright] faces and scrambled facial features (showing activation of the fusiform gyrus when exposed to the upright face). This is a proce... | [
"Basically, you have a dedicated face coprocessor."
] | [
"tl;dr Reading words needs to be learned, your brain is just awesome at reading faces by itself."
] |
[
"Can water be compressed to a solid?"
] | [
false
] | The 'normal' solid form of water is crystal, leading to a lot of 'negative' space and the common trivia about ice being more voluminous than liquid water. It seems like though, the crystallization is almost just getting in the way of what could be a more normal (to other molecules) solidification process. So is it poss... | [
"Keeping it at room temperature, you'd have to compress it to a pressure of about 10,000 atmospheres before it solidified. It wouldn't form regular ice, it would form something called Ice-VI with a different structure."
] | [
"Surprisingly no! not like most other substances. That's why water's so cool. Almost every other liquid can do that. Here's the crazy part; for the same reason, if you have ice just barely cold enough to be frozen, you can compress it into a liquid! If I try to push those molecules closer together, it would turn in... | [
"Adding on to the other answers, you might be interested to know that at one point we thought the exoplanet Gliese 436b was largely composed of ice at around 250 degrees C. I'm not sure if that's still the consensus, though.",
"http://news.nationalgeographic.com/news/2007/05/070517-hot-planet_2.html"
] |
[
"If we could somehow measure the capacity of our memory in terms of how we measure a computers memory, how much would the average brain have?"
] | [
false
] | null | [
"I tried looking for this before. you will see articles from back in early 2000's saying it's ~140 gigs (no idea where they got that number)",
"The problem is we don't fully understand memory storage yet, so can't really measure. It's briefly mentioned in this ",
"Scientific America"
] | [
"This isn't quite correct. Memories (of a sort) can be stored in the synapse (e.g., see ",
"here",
") or in single neurons (or at least small groups of neurons -- ",
"paper",
" and ",
"summary",
")."
] | [
"As far as we know effects like memory and thought are not localized to single neurons but are collective, emergent effects. So it's difficult to give a direct analogy to computer storage."
] |
[
"Has science demonstrated that whales have degenerate genes for mammal legs?"
] | [
false
] | It would be beautiful to link the phenological evidence to genomic evidence about the reason for those vestigial leg bones. | [
"PZ Myers explains what cetacean limb genes are doing ",
"here",
". Basically, the genes are the same as for land mammals but the execution of them has differed."
] | [
"Nice summary (one expects no less from PZ). The money-shot is at the end:",
"How do you make a whale? Clearly, you don't just \"lose\" the genes required to make hind limbs. You have to revise and add to the control information for existing banks of regulatory genes involved in limb formation.",
"Clearly, whal... | [
"Thank you. Excellent stuff."
] |
[
"Why can we 'feel' someone staring at us?"
] | [
false
] | null | [
"You mean if we actually see a face why do we look at it? We need to put objects into our fovea to resolve details and faces draw our attention as objects in the environment that are important, partly for social reasons and partly because whenever there is a face we usually look at it (which sounds circular, but al... | [
"You can't. This is called the psychic staring effect and there is no conclusive evidence that it exists."
] | [
"There are some on the wiki page or you can search Google scholar for the term"
] |
[
"If the fusion reactions in stars don't go beyond Iron, how did the heavier elements come into being? And moreover, how did they end up on earth?"
] | [
false
] | I know the stellar death occurs when the fusion reactions stop owing to high binding energy per nucleon ratio of Iron and it not being favorable anymore to occur fusion. Then how come Uranium and other elements exist? I'm assuming everything came into being from Hydrogen which came into being after the Big bang. Thank ... | [
"There are a couple of processes that create elements heavier than iron. The s-process (s for 'slow') happens in large stars, where atomic nuclei capture free neutrons, increasing their mass. Occasionally they'll undergo beta decay, increasing their atomic number. This takes a long time, but because there's just so... | [
"\"R-process only occurs in core-collapse supernova\" is a bit outdated. The ",
"recent double neutron star merger",
" showed evidence of r-process elements being formed in large enough amounts to explain ",
" r-process production, while simulations of core-collapse supernovae have had difficulties in making ... | [
"As an addendum to this, the belief that heavier elements do not form during the life of a star is essentially correct. While in the s-process fusion of heavier elements does occur (very slowly and very infrequently), the r-process (that which creates the majority of heavier elements we see today) is accompanied by... |
[
"Besides Human & Apes, do any other animals find certain things humorous?"
] | [
false
] | null | [
"Wikipedia has your back",
"."
] | [
"That link goes to a 404."
] | [
"Check out the title story from the book \"The Parrot's Lament\". Decide for yourself. I believe it. When people lie, they're generally not this creative. ",
"https://companionparrotonline.com/humor.html"
] |
[
"If the sun somehow captured an asteroid from outside the solar system would we be able to examine its composition and identify it as an extrasolar object?"
] | [
false
] | null | [
"Howdy! I've removed your post for its open-ended and speculative nature. I can redirect you towards ",
"/r/AskScienceDiscussion",
" which better suits such posts."
] | [
"After giving it a second look, I let your second submission through."
] | [
"After giving it a second look, I let your second submission through."
] |
[
"Since sound waves require a medium to travel through, and bone is a very dense one indeed, would you be able to hear yourself in space?"
] | [
false
] | Also, would you conceivably be able to hear someone if you held their hand or put your foreheads together and then spoke? Just a question out of morbid curiosity. | [
"Your vocal cords create pressure waves in the air surrounding them. Sound travels through bone by having a pressure wave come into contact with your body and the wave continues to propagate along the path. If there is no air, there is no wave to create. So nothing can cause the pressure wave to travel through your... | [
"Not a scientist in this area or involved in science professionally at all, but I recently saw an interview with a veteran US astronaut who said that on EVAs if the communications went dead the astronauts could talk to each other by putting their heads together and the sound would travel through the glass(or whatev... | [
"You can try these things out here on our planet, Earth, and see if they work; get a friend and some heavy-duty ear muffs. Putting your heads together and talking is unlikely to do anything, but if you talked against a balloon and held it against their ear the pressure wave would still be able to propagate.",
"Mo... |
[
"How is a three cylinder engine balanced?"
] | [
false
] | Take four cylinder engines, for example: you can see in how there is always one cylinder during combustion stroke at any given time, so there's never a lax in power. Engines with 6, 8, 10, or more cylinders are similarly staggered. So my question is how they achieve similar balancing with a 3 cylinder engine. | [
"you can see in this animation[1] how there is always one cylinder during combustion stroke at any given time, so there's never a lax in power ",
"Because of the way you phrased your question, I don't believe you are talking about how counterweights work. \nBriefly, counterweights are placed on the crankshaft ... | [
"That is a brilliant question.",
"\nWhile the power stroke lasts 180 degrees, the power obtained from that stroke does not.",
"\nMore specifically to answer your question, imagine each piston individually. ",
"If you have a one piston engine, and it has its power stroke, it then has 3 other strokes where it ... | [
"Thank you for your response. You are correct in that I was not asking about counterweights (but I did get some interesting responses regarding them). ",
"Since a power stroke only lasts for 180 degrees and a three cylinder engine's strokes are 240 degrees apart, wouldn't the 60 degrees between the two make for s... |
[
"Does an 8-hour sleep from 3-11 AM different from an 8-hour sleep from 10 - 6 AM?"
] | [
false
] | My dad keeps on telling me "Your immune system is weak because you always sleep late." However, I get full sleep but on a different schedule than them. I sleep for more or less 8 hours but from around 3 am onward. Does it make a difference than sleeping early? | [
"Yes it does differ. Our bodies are meant to be awake during daylight hours, and people who do things like work night shifts have been shown to have greater risk for heart disease and diabetes. ",
"http://healthhub.brighamandwomens.org/sleep-research-is-the-night-shift-bad-for-your-health#sthash.FsRd5q8x.mdWSnNib... | [
"That study combines insufficient sleep as well as disruptions to the circadian rhythm (like having an inconsistent sleep schedule), right?",
"OP seems to be getting sufficient sleep, and his sleep schedule seems to be consistent... I don't think that study serves as sufficient evidence that there's a difference.... | [
"There are different chronotypes. Your circadian rhythm (peak levels of awareness, hormones, etc.) can be different than others. In some people it is very pronounced, and this is called Delayed Sleep Phase Disorder.",
"https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder",
"The short of it is that if you ... |
[
"Why are galaxies not spherical?"
] | [
false
] | null | [
"Because they're spinning."
] | [
"Yes",
"The Earth is under the same force as it rotates on its own axis. That is why it's shape is approximately an oblate spheroid, rather than spherical (excluding local topography)."
] | [
"Which in turn stretches it out?"
] |
[
"Why does wool/neoprene keep you \"warm\" when wet?"
] | [
false
] | I've taken several wilderness first aid classes now and spend a bit of time kayaking and whatnot. I keep hearing that wool or neoprene or a couple other synthetic materials will keep you warm even when you're submerged in water. I've also heard cotton called the "death cloth" in Search and Rescue, because it will get y... | [
"The key concept here is thermal conductivity [abbreviated as k for some reason]. Water has a significantly higher k value than air does, so water can 'move' the heat much more quickly. Heat always travels from hot to cold [excluding systems with a power input, which your body is not]. So wet clothing will help ... | [
"Also, neoprene is a solid foam, and inside it there are tiny bubbles of air, that act as an insulator. A side effect of that, for divers like me, is that, when you dive deep, water pressure compress the bubbles, the wetsuit becomes thinner and so less insulant."
] | [
"Water drains the heat off your body about 25 times faster then air does. When cotton gets wet it no longer has insulating properties and simply lets the heat escape. On the other hand wool even when wet will help trap some of that heat from escaping. Neoprene on the other hand lets the water in when but does not... |
[
"Can a fan blow air through a vacuum"
] | [
false
] | null | [
"Just to clarify, you're wanting to take the air out of a chamber with your wet item in it, and then re-introduce air, to blow through the chamber to dry it off? This sounds like an odd combination of two different methods, really - what's the point behind evacuating the chamber before passing the wind through?"
] | [
"The plan is not to re-introduce air. The fans would be part of the vacuum chamber. In there with the wet beans. Thanks for reply!"
] | [
"Well, if you've taken all of the air out of the chamber to create the vacuum, there won't be anything left to blow!"
] |
[
"I know this is a controversial issue, but what are your thoughts on genetic evidence for races?"
] | [
false
] | (or lack thereof) I'm a noob to genetics, having only had high school biology and a 100 level course on it so far (which didn't expand on it too much). I've seen the wiki article and some of the abstracts it's linked to. I'm under the impression that there's yet to be a definite consensus among population geneticists b... | [
"Not quite. Racial groupings are somewhat arbitrary but not analogous to the things you mentioned, because racial groupings come from large sets of genes and are in some sense closed.",
"For instance, two African parents will always produce an African-looking child. Two Asian parents will always produce an Asian-... | [
"Not quite. Racial groupings are somewhat arbitrary but not analogous to the things you mentioned, because racial groupings come from large sets of genes and are in some sense closed.",
"For instance, two African parents will always produce an African-looking child. Two Asian parents will always produce an Asian-... | [
"Of the 74 people who have run the 100 meter in less than 10 seconds, only one is white. All of the others are of West African/Caribbean descent.",
"I wonder how much of that is due to the majority of \"white\" people not training to be good at running. I mean, the vast majority of hockey players in the NHL are \... |
[
"Why are the Great Basin, Mohave and Sonoran Deserts considered distinct?"
] | [
false
] | Looking at a map, these three deserts look like they are right next to each other. Why wouldn't they be known as one big desert? | [
"Mostly because of distinct plant life and weather. In the Sonoran desert you have several varieties of cacti that are not present in either the Mojave or Great Basin desert. The Sonoran also has two rainy seasons, summer monsoon and winter rains while the other do not. Also separting the Mojave and Great Basin is ... | [
"Sounds like they are quite distinct. Thanks so much! I'll have to spend some time looking further into deserts, this is quite interesting."
] | [
"Joshua Tree National Park connects the Mojave and Sonoran Deserts, and if you look closely you can see differences in the geology and topology along the boundary line. Among the many amazing reasons to visit Joshua Tree, if you're interested in deserts, the rangers and docents at the visitor centers can give you s... |
[
"Has anyone ever invented a (non virtual) system of writing which is more efficient than the roman alphabet?"
] | [
false
] | We all know that there are many ways of writing, some of them still widespread in the world like the Japanese and Chinese pictographs. What i am wondering is, did anyone ever come up with a more efficient writing system than the one we currently use? If yes, why didn't it catch on? | [
"Consider ",
"stenographic systems",
", which allow people to write down information more quickly, at the expense of robustness.",
"The ",
"Shavian alphabet",
" was an attempt to create a alphabet for English that was ",
"featural",
" and had near-perfect ",
"phonemic orthography",
" - both featur... | [
"It's difficult-to-impossible to objectively rank ",
"writing systems",
" by their efficiency. ",
"Another questioner got this response",
"; as you can see the conclusions were nowhere near definitive."
] | [
"I've heard Hangul (written korean) is the most efficient, but I can't find any reliable sources online. ",
"Wikipedia",
" cites:",
"Numerous linguists have praised Hangul for its featural design, describing it as \"remarkable\", \"the most perfect phonetic system devised\", and \"brilliant, so deliberately d... |
[
"Why do I never see dead Pigeons in cities?"
] | [
false
] | null | [
"An article on this very subject: ",
"http://www.theatlanticcities.com/neighborhoods/2012/05/why-arent-cities-littered-dead-pigeons/2038/"
] | [
"Thanks, what a perfect answer!"
] | [
"Find a bridge with anti bird nets under it and look up. There will usually be at least one dead pigeon stuck in it. "
] |
[
"Are people executed via firing range able to hear the gunshot, or would they die before the sound reaches them?"
] | [
false
] | [deleted] | [
"Being shot is not instantaneously fatal. That's an artifact of movies and TV shows.",
"A gunshot wound to the thorax is generally instantaneously incapacitating due to the impact alone. But it does not typically result in an immediate loss of consciousness. There have been many, many documented cases of people s... | [
"Have a buddy who got shot in Iraq with a rifle (AK-47 I guess, or whatever the insurgents use) and he had no idea what hit him. He thought one of his squad mates just leveled him with a sucker punch and it wasn't until they started returning fire and one guy rushed over to drag him away that he realized \"huh, I ... | [
"Speed of a bullet",
": 180-1500m/s",
"Speed of sound",
": 340.29m/s",
"Then there's also the time it takes for a sound to register in your brain.",
"So, they'd probably get hit by it before they hear it.",
"But, whether or not they'd ",
" the sound before dying.. I do not know."
] |
[
"Could I increase the frequency of a radio wave emitted from an antenna to a point where it is in the visible light spectrum? Could I see it?"
] | [
false
] | I've always wondered this because the two different phenomena, emitting a radio signal and visible light, are placed on the same spectrum. I suspect no is the answer, but why? | [
"Well.. you can always try running towards the antenna is extremely high speeds. That should blueshift the emitted waves.",
"Otherwise, I'm afraid antennas stop behaving according to conventional antenna theory by the time you reach IR or terahertz frequencies. You cannot produce a conventional oscillator that... | [
"It is all the same thing but as the other responders point out, it's the assumptions built into the processes that start to break down - the technique itself should still work. The idea behind antennas is that you are using a wire (some ideal object with 0 resistance that transmits electric signals) and an oscill... | [
"Well, they ",
" make radio waves via passing electricity through a gas: ",
"Spark Gap Transmitter",
".",
"It all ultimately comes down to physics - you can convert electricity to EM waves by a huge variety of different methods, but the efficiency will vary wildly. For low-to-medium RF ranges, a simple osc... |
[
"What is the grey \"flesh\" between the salmon's skin and the pink flesh? Is it the same/edible as the pink flesh?"
] | [
false
] | null | [
"The grey flesh is slow twitch muscle and the pink fast twitch. Salmon move through a much denser medium (water compared to air) so it takes a lot more muscle to move quickly, say from a predator. This means that the ratio between slow and fast twitch muscles is very different in fish compared to humans.",
"One m... | [
"Biologoy: the study of the non-Jewish human."
] | [
"Although I am not a marine expert, I have, as someone that loves cooking, researched this. The white meat that you see in a salmon filet is pretty much pure muscle. The gray matter has a higher concentration of fats and such. That's why it's on the outside and why, if you smell it, it sellsbad - it's full of fatty... |
[
"What is the carbon purity of cremated remains? (three part question)"
] | [
false
] | I have seen the places offering to have a diamond created out of the carbon remains after cremation, but I know that it can only take about 20 atoms of titanium to turn a synthetic diamond a brilliant yellow. I was just wondering if creating one out of cremated remains, how pure is the carbon content likely to be? Sec... | [
"Cremation ash hardly contains carbon at all. It's mostly oxidized bone matter. It's practically ",
" minerals. Inorganic ash. If they're turning human remains into synthetic diamonds, they'd first be doing quite a bit of chemistry to separate out the carbon, so the \"purity\" of the ash isn't really relevant. I ... | [
"If you burn organic matter under the right conditions you can generate a lot of soot, which I assume is what they're doing."
] | [
"It's not what you do in a crematorium oven; that's a pretty complete combustion. And it doesn't seem like these companies are doing the actual cremating, but just making diamonds out of whatever carbon they can get out of the ash."
] |
[
"Is there any scientific basis to claims that it's possible to influence the sex of your baby?"
] | [
false
] | [deleted] | [
"Some studies have shown that the sperm with the X chromosome live longer than the than the sperm with the Y chromosome. This means that 'female' sperm have a greater life span than 'male' sperm. However, 'male' sperm are considered 'better swimmers' as they have greater motility -- they live fast and die young (ha... | [
"I don't think there are mega studies because a lot of the necessary controls would require conditions that wouldn't be ethical. Many (I would hope most) people who are trying to conceive are not willing to risk trying different things (like going through a starvation diet for example) in order to maybe get a child... | [
"I don't think there are mega studies because a lot of the necessary controls would require conditions that wouldn't be ethical. Many (I would hope most) people who are trying to conceive are not willing to risk trying different things (like going through a starvation diet for example) in order to maybe get a child... |
[
"If you map hurricane Irene's path, you'll find it's been staying on the continental shelf, roughly skirting the border between it and deeper waters. Is this coincidence or is there a reason for that?"
] | [
false
] | null | [
"http://imgur.com/ELknQ"
] | [
"It's because of the pattern of prevailing winds.",
"There's a ridge of high pressure that sits at approximately latitude 30N during the summer. It's called the ",
"subtropical ridge",
".",
"Winds south of the subtropical ridge are the ",
"trade winds",
", which blow east to west. Therefore, hurricanes ... | [
"The eastern coast has outward ",
"prevailing winds",
". ",
"This also affects ocean waves.",
"I wager that hurricanes are channeled along the edge of the shelf because that's where the winds are the strongest. I also gather by looking at that picture in the wiki article that the Atlantic trades meet the co... |
[
"Why do I tend to find people prettier if I like them and uglier if I dislike them?"
] | [
false
] | null | [
"Hi evilbutcut3 thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the fol... | [
"Hello,",
"We can't speculate about your personal preferences here."
] | [
"Hi, I have actually talked about this to friends of mine and it seems that several of them also experience this. Thank you for answering though, I guess I'll remove this post :)"
] |
[
"If a superconductive wire can hold a current indefinitely, does that mean you can keep adding to the current and if so, how do you determine the capacity of a given length of superconductive cable?"
] | [
false
] | Forgive my ignorance. I would guess that "capacity" would be described in terms of amount of electrons? | [
"Superconductors have a \"critical current\" beyond which the superconductivity is broken, and you no longer have a superconductor, just a normal conductor."
] | [
"What gives rise to this limit, some sort of saturation effect?"
] | [
"the exact mechanism is unknown, but when the ",
"cooper pairs",
" is given enough energy it will break apart into two electrons resulting in the end of superconductivity. If the current is increased in a superconductor you don't end up with more carriers, but rather each carrier moves faster (remember I=dQ/dt... |
[
"When white light hits a surface and reflects a color (and absorbs other wavelengths), what is happening at the reflection point?"
] | [
false
] | So if I take red paint, it's red because it absorbs everything except red. So white light has struck it, and reflected only the red. On a molecular level, why? | [
"Atoms have electrons orbiting the nucleus. These electrons move very fast and their position is not definite, so we will call them an electron cloud. When the cloud is centered around the nucleus, there is no net force on the cloud. When the cloud is pulled to one side, there is an electrostatic force pulling it b... | [
"So the energy from the non-red photons is transferred into the electron cloud and then that energy becomes what? Heat?"
] | [
"Generally, yes. That is why a black surface out in the sun would generally heat up more than a white surface."
] |
[
"Approximately how fast is Sol traveling relative to the center of the Milky Way galaxy?"
] | [
false
] | null | [
"According to ",
"this NASA site",
", about 828000 km/hr, or 230 km/sec."
] | [
"It does my head in when people use Sol and Luna trying to sound intelligent. "
] | [
"It does my head in when people use Sol and Luna trying to sound intelligent. "
] |
[
"How does Mercury produce toxic fumes if it is a heavy metal?"
] | [
false
] | null | [
"Everything, including the metal mercury has a vapour pressure. The vapour pressure of mercury at room temperature happens to be greater than that of other metals. ",
"The actual toxicity of elemental mercury has, perhaps, been overstated in popular opinion. Mercury salts, however, and in particular organo-mer... | [
"An important part that you mentioned, but perhaps not explicitly enough, is that the toxic 'fumes' from mercury are mercury vapor itself -- the gas phase of the metal."
] | [
"I would like to add that mercury is naturally found in the environnment, in air, waters and soils. At room temperature, elemental mercury slowly forms vapor when in contact with air. Mercury vapor also comes from volcanic eruptions, erosion of rocks, and human industry."
] |
[
"Why don't we scale wind turbines down?"
] | [
false
] | [deleted] | [
"It is hard to measure everything's stress in a computer. Imagine that we test for 95% of the stuff, but BAM, we didn't check the sturdiness of the balls in the ball bearings, which creates a wobble and does damage to system A, which manages system B, which controls system C, which is the safety control for the who... | [
"The other reason turbines are as huge as possible is that short wind towers have less wind and more turbulence. A 120 foot tower will give you about ",
"double the power",
" vs ground level.",
"Small personal wind turbines tend to end in disappointment for many reasons. Go big or go home."
] | [
"We're now testing 164 metre diameter rotors.",
"How is this not a fairly trivial thing to model or figure out? Like, honest question, why can't I just mock up a bunch of diameters in say a CAD program and check?"
] |
[
"Why does it sometimes take cold air and other times take hot air to defog my windshield?"
] | [
false
] | null | [
"it never \"takes\" hot or cold air. what it takes is \"dryer\" air.",
"when you use cold air either the humidity difference was VERY small or your AC compressor is kicking on to \"dry\" the air your using.",
"this is why older cars without AC have \"really\" hot heaters.",
"the other way to get the effect is... | [
"While humidity is a factor, removing humidity isn't always a realistic solution. The cause of fogging is temperature differential. The air moving over the windshield tends to heat or cool the glass to a similar temperature, this can cause condensation. Condensation, which you likely know, is caused when air is coo... | [
"it never \"takes\" hot or cold air. what it takes is \"dryer\" air.",
"This isn't quite correct. ",
"\"Fog\" occurs when the temperature of the glass is below the condensation point, allowing water vapor to condense on the glass. Increasing the temperature of the glass such that it is above the condensation po... |
[
"If I leave my phone charger plugged into an outlet, but unplug my phone from the charger, am I really \"wasting\" electricity?"
] | [
false
] | null | [
"\"Examples of work being done that isn't useful include leaving a light on in an empty room...leaving a cell phone charger plugged into an outlet when the cell phone is already fully charged, or is no longer connected to it...\" (",
"Green-Energy-Efficient-Homes.com",
")"
] | [
"Great, thank you!:)"
] | [
"Not all cellphone chargers are The same. Is there the same waste regardless of whether the charger is an old fashioned transformer, or a modern switch mode power supply?"
] |
[
"Is water the only chemical more dense as a liquid compared to a solid?"
] | [
false
] | null | [
"No, there are other examples of substances that display this property.",
"Density of Gallium (s) = 5.91g/cc , Gallium (l) = 6.1 g/cc",
"Also, germanium, silicon. Quite a few more."
] | [
"Is there any common thread to explain why these and only these possess this shared property? "
] | [
"Those are elements; are there any molecules like water that are most dense as a liquid? ",
"Of course, there is always ",
"amorphous ice",
" like HDA and VHDA that would not float (1.17 g/mL and 1.26 g/mL respectively). ",
"The common thread would be hydrogen bonding. You'd need a molecule with a good n... |
[
"Why is slightly rotating things while pulling out easier, than only pulling without rotating?"
] | [
false
] | Sry for MY bad english. And thanks for any reply! | [
"For a variety of frictional and adhesive forces, the strength of the force is reduced once an object is in motion. Additionally, for a wide enough object, it's generally easier to exert a torque to produce twisting than a linear force for pulling, because torque increases with the radius of rotation, independent ... | [
"In high school physics class, you probably learned that static (unmoving) friction is higher than kinetic (moving) friction. This is usually true. What BoxAMu is saying is that it's often easier to break the static friction through a torque (rotational force) than by linear force."
] | [
"Thanks to both of you! After 5 minutes of grinding gears in my Brain because of translating difficulties, i got it now! :)"
] |
[
"Is it possible for a planet to have an ocean without an atmosphere?"
] | [
false
] | null | [
"Yes, it's possible",
"No, it's really not.",
"If a liquid ocean existed without any atmospheric pressure, it would quickly boil until either the liquid was all gone, or there was enough boiled vapor to reach equilibrium pressure with the liquid. In other words, if you had a water ocean, it would very quickly c... | [
"Yes, it's possible",
"No, it's really not.",
"If a liquid ocean existed without any atmospheric pressure, it would quickly boil until either the liquid was all gone, or there was enough boiled vapor to reach equilibrium pressure with the liquid. In other words, if you had a water ocean, it would very quickly c... | [
"It all depends on your definition of ocean. Since the equilibrium point between a liquid and its vapor determines condensation and evaporation of said material, a liquid without a significant pressure of its own vapor (i.e., an atmosphere containing such vapor) would ultimately evaporate.",
"However, if you defi... |
[
"Why are plants green and not black?"
] | [
false
] | [deleted] | [
"Actually, black objects DO reflect 'light' - they reflect parts of the electromagnetic spectrum that we can't see. Anyways, you're running on the assumption that evolution creates the most optimal possible solution to a problem, when what it really does is simply allow the most optimal existing solution to grow wh... | [
"yes, but i thought interacting with you fine people of science might have more interesting answers; thanks for the link, though! =D"
] | [
"I was only thinking of the coloured light that we see, not the other wavelengths :D nice explanation of evolution, btw. I like it. "
] |
[
"Can you cook rotten meat enough, so that it becomes safe to eat?"
] | [
false
] | So you leave some meat in the fridge WAY past it's expiry date. You open it up just to be sure, and it's developed a rancid odour, and turns your stomach immediately. Lets assume its eat it, or die. Maybe I'm wrong, but I am under the impression, that the meat is now bacteria ridden. And I'm also under the impression t... | [
"You can kill the bacteria with heat, but there's no guarantee that toxins already produced by the bacteria will be destroyed by the heat.",
"Example is Staphylococcal Intoxication:",
"When Staphylococcus bacteria get into warm food and multiply, they produce a toxin or poison that causes illness. The toxin is ... | [
"That's exactly what I was looking for. I didn't realize pathogens can emit toxins.",
"Many Thanks!"
] | [
"I should add for the sake of completeness that there will be some temperature high enough to inactivate the toxins. However, there is also the concern that the toxins could ",
"reactivate",
" after cooling. As a matter of pragmatism, it is safest to assume that once food is rancid it is not practical to try ... |
[
"When you can't remember something why do you still know enough to recognize people's incorrect suggestions?"
] | [
false
] | For example: if you can't remember an actors name and people suggest a similar name you will know that it's not quite right. If you can't recall what it is to begin with, how does that work? | [
"The information may still be in your brain, you simply haven't yet been able to consciously access the proper memory. Or you have a partial memory, and it needs to be reinforced (for example, you can remember that the actor's name begins with the letter \"B\") to be restored. Long term memories need to be accessed... | [
"Knowing something about one thing doesn't mean you know it about another.",
"I don't know who acted in the 1928s production of whatever, but I know it wasn't Keanu Reeves [or was it? He is immortal...].",
"So just because I can confirm one fact doesn't mean I know another."
] | [
"One prominent theory of memory recall is that attractor networks are activated, are recurrent, and will ultimately fill in the missing blanks. The attractor network is a population of neurons. This population is self-activating in a loop. If you stimulate enough of the neurons, then all of them will get activated ... |
[
"Our lungs are asymmetrical, and it appears that they have significantly different volume/surface-area ratios. Do they consequently absorb oxygen and transfer CO2 at different rates?"
] | [
false
] | null | [
"I used to be a respiratory therapist but that was more than thirty years ago and I did snooze through a few classes. Let's see what I remembrr.",
"Lungs are indeed asymmetrical. The right lung has three lobes, the left only two. The larger lung has more alveola (tiny balloon like sacs that share a membrane wi... | [
"Exactly, gas exchange per unit volume of lung is equal, but total amounts are not. "
] | [
"Exactly, gas exchange per unit volume of lung is equal, but total amounts are not. "
] |
[
"Is it possible to transmit wireless data at the frequency of visible light? In that case, we could see the data transmission."
] | [
false
] | null | [
"It's done all the time. We can see the pulse, but as humans in most cases, we can't read it. Some remote controls use visible light instead of infrared light too. Think of Morse Code flashing between ships. It being another form of visual communication with visible light. Remote controls just use a faster flashing... | [
"Microwaves actually have much longer wavelengths than visible light (centimeters vs nanometers). They still go through walls better than visible light like you mentioned, but visible light would have a higher potential bandwidth."
] | [
"There have been attempts to commercialize a WiFi-like technology based on light for a while. They rather creatively named it ",
"LiFi",
". ",
"Other terms worth chasing for more information are ",
"Visible light communication",
" and ",
"free-space optical communication",
".",
"There have also be... |
[
"What do ants do when they are separated from the colony?"
] | [
false
] | I had an interesting experience with ants yesterday. They have been coming in through my kitchen window to feed on food in my kitchen. I closed the gap in the window that they were coming in through, but some ants were still inside the house. I found the behavior of these remaining ants interesting: They huddled into "... | [
"I'm not a scientist, but I am an avid ant keeper. As a result, I've done a lot of ant research. ",
"Firstly, most ants navigate outside of their nests using two methods: pheromone trials, and counting their steps. ",
"Pheromone trails will be laid by ants when they find good, a danger, etc. They can follow t... | [
"that mean if the ant walk on a paper sheet and then you move it, she will be lost ?"
] | [
"I've observed ants travelling about 100m crim their nests, so even during routine activity, they can move around quite a bit. ",
"I'd believe an ant will continue to travel in an ever-widening circle (it's an instinctual response) until it does of dehydration or other misadventure. ",
"So, if an ant was luck... |
[
"Why are high divers okay jumping into water from high up, but jumping off a bridge will kill you?"
] | [
false
] | null | [
"Technique is part of it but I think everyone is neglecting the fact that an Olympic high dive is around 33ft I believe. I'm not sure what the average bridge height is, but most people would picture a much higher drop when imagining a fall from a bridge. If you jump off a 33ft bridge youre going to most likely sur... | [
"All answers I've seen here are emphasizing technique. You have to hit the water right. And that certainly has a large effect. But there are two others that probably account for the large number of deaths (remember not everyone jumping off a bridge dies. I've seen \"It's a Wonderful Life)",
"1) Height is a bi... | [
"Bubblers obviously break the surface tension and reduce impact as a result.",
"Nope. The bubbles are simply to make the surface visible. The diver needs to know where it is so he can be in proper orientation when he/she hits it."
] |
[
"Since our moon revolves with the \"dark side\" always facing out, why did it form into a relatively perfect sphere?"
] | [
false
] | This is especially strange to me considering it was formed by collisions of multiple bodies. Since it isn't rotating on its own axis, wouldn't centrifugal forces stretch it? | [
"This was super helpful. We are all grateful that you were here to contribute. Your mastery of all things lunar has left us in awe. ",
"Your comprehension of etiquette, if any, is vague and fractional. You don't really know enough about being helpful to pose a decent answer, and you haven't done it. ",
"Tool. "... | [
"The moon ",
" spinning on its own axis. Due to tidal locking this spin is synronised with its orbital period.",
"The moon did not always show us the same face. It formed and then over millions of years it got totally locked."
] | [
"Yes. Centrifugal force also stretches the earth. It's not obvious, but it is significant. The moon is further warped by the tidal forces from the earth. Earth is pulling more an the part closer and less on the part further, so it makes the moon somewhat football-shaped."
] |
[
"Why can't you donate blood after receiving eye surgery?"
] | [
false
] | null | [
"You may have received something like a corneal transplant and acquired a disease from that donated tissue. Rather than delving into the specifics of the operation they may simply disqualify you out of an abundance of caution."
] | [
"Heck, they disqualify you if you've had gay sex anytime in your entire life, I get that question every time. I think that might be changing though."
] | [
"They also disqualify all British people born before 1996 from ever donating in the USA, basically. ",
"EDIT: in Britain for more than 3 months between 1980-1996... sorry for oversimplifying"
] |
[
"How is the time component of spacetime expanding?"
] | [
false
] | Is it wrong to say that it's only space that's expanding, and not spacetime? Is it just that the two are so closely linked that the expansion of space on its own affects time, and therefore we say spacetime expands? | [
"Will do. Hopefully they won't notice me struggling to read it off my left palm as I explain it to them."
] | [
"If anybody bugs you about it, just tell them that technically the scale factor only appears in the space components of the FLRW metric, but since the metric is an equation of ",
" it's fine to say \"spacetime.\"",
"That oughta shut 'em up."
] | [
"There are currently no observations that can't be explained by assuming time ",
" undergo any kind of expansion, or other change in its geometry. More technically speaking, if you look at the FLRW metric equation that describes metric expansion, you see there's nothing funny going on in the time component. It's ... |
[
"How, on a chemical level, does tempering chocolate work?"
] | [
false
] | I know tempering chocolate in the culinary world works by melting the chocolate, lowering the temperature and then raising it one last time to a very specific temperature, but what's going on chemically that makes the chocolate harden like that? | [
"I study material science and was once baffled by the similarity between chocolate tempering and steel tempering, here is what I remember from chocolate tempering:\nChocolate is made out of cacao powder, sugar and cacao butter. The cacao butter, when it solidifies, can adopt different structures with different org... | [
"Seyler360 already explained it pretty well but I thought I'd add a source.",
"",
"https://acselementsofchocolate.typepad.com/elements_of_chocolate/TEMPERINGCHOCOLATE.html",
"",
"https://www.sciencefriday.com/educational-resources/chocolate-crystal-concoctions/",
"",
"Basically at certain temperature... | [
"Thanks for the reply! I learned about metal tempering when I went to college for welding, but the thought never occurred to me that the same would apply to chocolate!"
] |
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