title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Can non-human animals be allergic to other animals? E.g. can a cat be allergic to me?"
] | [
false
] | null | [
"Heres an article about cats which are allergic on humans. Sorry, the ",
"article",
" is in German. Can translate if you need. ",
"Edit: Found an ",
"English article"
] | [
"Very, VERY good question! The thing is, animals tend to be far more resistant to allergens and a lot of bacteria than humans are (EDIT: because they have adapted to living in spaces that aren't as clean as ours), but, as pointed out ",
"below",
" animals can be allergic to humans, although it is much less comm... | [
"This isn't true. Animals can and do, frequently, have allergies (often, though, allergies are manifested in dermatologic problems such as pruritus). And also do get infections... they're not \"resistant\" to bacteria.",
"Edit: Since I'm apparently being downvoted, here is some more info, specifically about cat a... |
[
"Do computer simulations of the visible universe take into account the current position of stars considering the speed of light?"
] | [
false
] | [deleted] | [
"But \"where are they now\" is not a very deep scientific question. Science is more than mere stamp collecting. Yes, the real positions of stars and planets as compared to their observed positions could indeed indicate interesting interactions, IF we had the where-are-they-now data. But we don't. Any simulation of ... | [
"But \"where are they now\" is not a very deep scientific question. Science is more than mere stamp collecting. Yes, the real positions of stars and planets as compared to their observed positions could indeed indicate interesting interactions, IF we had the where-are-they-now data. But we don't. Any simulation of ... | [
"It would be possible to do that, but tedious and uninteresting. It's not the current positions of bodies that are important, but the nature of their interactions. ",
"Mapping \"current positions\" wouldn't do much to the cone structure caused by the zone of avoidance that you're talking about, because the distan... |
[
"Does time have to exist?"
] | [
false
] | [deleted] | [
"Yes, special relativity has been experimentally tested. It's one of the most thoroughly tested scientific theories there is.",
"And yes, time exists."
] | [
"I think it's worse here to improperly cite a quote than to not cite at all. ",
"-Wolfgang Pauli"
] | [
"In that case, to avoid the conflict with memes, I'd just leave off the attribution in the future. I think it's worse here to improperly cite a quote than to not cite at all."
] |
[
"How much good would it do to have plants (that need high amounts of CO2) put on the roof of every skyscraper in every city?"
] | [
false
] | Right? Doesn't it seem like a somewhat simple solution to at least help a ? I know some plants require more CO2 than others, so why not use the ones that requier the most (or genetically modify ones to require excessive amounts) to put on the tops of skyscrapers and buildings to absord the absurd amounts emitted below... | [
"When a plant removes one ton of carbon from the atmosphere, it it puts the carbon ",
" - the plant's body is ",
" largely of carbon.",
"So what that means is: for a plant to absorb one ton of carbon, the plant must ",
" one ton of weight. Each time it absorbs another ton of carbon, the plant gets at least... | [
"a lot of people are not aware that a plant's mass comes from the air"
] | [
"In the end, any attempt to remove carbon from the atmosphere is going to have to involve storing the carbon somewhere. But it certainly doesn't have to go into space. Just into long-term storage. By long-term, I mean long enough for us to come up with something better. Maybe 100 years, say. That's easy in sma... |
[
"did dinosaurs roar?"
] | [
false
] | do their skeletons tell us anything about that? i know some lizards hiss loudly, but i dont know about roaring. | [
"Not sure why this is tagged as archaeology, since it's not human related. "
] | [
"I'm guessing nothing like that has been.",
"\"Skippy\", but I don't know how well the throat was preserved",
"- Apparently \"somewhat\" -",
"Of the respiratory system little has been preserved. No traces of the lungs have survived, nor of any air sacks. The sole element still present consists of a seven mi... | [
"A better comparison would be bird sounds."
] |
[
"Why is it so much worse to get chicken pox as an adult than as a kid?"
] | [
false
] | I always assumed our immune systems got better as we got older (eventually declining with old age obviously) | [
"In adults, the varicella zoster virus (responsible for chicken pox in children and shingles in adults) wreaks havoc on the immune system. The virus is actually a latent type and is contracted as chicken pox as a child, recedes up into neural cells, only to descend back to the surface and show up as shingles (via t... | [
"Maybe I'm reading this wrong but I don't feel this actually answered the question.",
"It explains it, sure, but I'm still unsure as to why it's worse to contract the disease as an adult.",
"In my personal (inexperienced) opinion, it's going to be something to do with how children are still growing therefore in... | [
"I just read a couple of interesting articles about this. It sounds like a decrease in ",
"cell mediated immunity",
" towards the virus as we age is the culprit. During an infection, our body responds in two ways: a cell-mediated response (wikipedia has a better explanation that I could put here), or a ",
"... |
[
"If a were shot in the head and killed, would he/she hear the gunshot before dying?"
] | [
false
] | [deleted] | [
"This would depend on the speed of the bullet and distance you are being shot from.",
"let [the speed of the bullet] = s. s∈R>0\nlet [the local speed of sound] = y. y∈R>0\nlet [the latency to 'hear'] = c. c∈R>0\nlet [the distance the bullet must travel] = d. d∈R>=0\nlet [you hear being shot] = b. b∈{true,false}\n... | [
"Be fair, a bullet traveling at 300 m/s will take about 0.5 ms (where a neuron's takes a full 5ms to fire at the maximum rate of 200hz) to pass through the entire brain. But yeah, since all but the very slowest bullets travel faster than nerve impulses, the bullet would get there before the message of \"ow\" did."
... | [
"My brother got shot in the head a few years ago. The thing that saved his life was that he saw the muzzle flash and turned to look in that direction. He said he does not remember hearing the sound of the gun, but that may be because he just doesn't remember hearing it or was not paying attention to the sound. ",
... |
[
"How do epidurals work?"
] | [
false
] | I feel like I've heard a lot of differing answers on this, particularly in regard to child birth. From "the woman doesn't feel a thing" to "the woman feels everything but doesn't remember the pain." Well, what is the actual mechanism? Is the medicine blocking some function in the brain? Is it numbing? Just curious, thanks! | [
"It’s an injection of anesthesia into the spinal canal at a certain level which then “numbs” the nerves below that point. The idea being to numb to some extent those nerves most commonly agitated during labor. Not really anything to do with the brain other than signals coming from the nerves in a woman’s pelvis are... | [
"It feels like you are pushing a needle through an eraser when you’re going through the interspinous ligament, then there is an almost imperceptible grittiness as you go through the ligamentum flavum. You know when to stop when the needle tip reaches the epidural space and you get a loss of resistance to injection.... | [
"Not a sciencey answer here, but first hand experience via child birth. Once the medicine is injected, you feel nothing while laboring. I took a nap. However, they turn the medicine off when you need to push so you regain feeling and can push. I felt every second of the actual birth. The epidural however enabled me... |
[
"Are older/ elderly people's discs between their spine more flattened or dereriorated (on avg.) vs. a younger one?"
] | [
false
] | null | [
"In short, yes they are. ",
"Research suggests that over the age of 40 years old, 60% of people show degeneration in a least one of their discs. This shows the early onset of degenerations, and after, this then worsens.",
"Intervertebral discs have two principle parts to their structure. (1) A fibrous outer she... | [
"no thanks! that helps a lot.\nI kind of have a follow up question which I realized it what Im more going for. \nSo, if I play a bunch of sports or do a lot of lifting. So like Soccer, where theres a lot of sharp angle cutting and change of direction. And squats, well.. because of the compression. Will that make my... | [
"Not necessarily. If you exercise, stretch, warm up properly and don’t push your body beyond its physical limits (like twisting a knee so much it strains, sprains, or tears a ligament for example) than you will be fine. If anything the exercise and sports more than likely help. The body grows stronger where it is n... |
[
"The connection between electrons and photons?"
] | [
false
] | So I'm confused about the nature of photons and electrons, and how they interact with each other. From what I understand, two photons can form an electron together, but photons are also used to transmit the electromagnetical force between charge carriers such as electrons. And they have the ability to knock electrons away from their cores in metals. So what are electrons? A bunch of photons together? Something completely else? Do they transmit photons or something? And why do they have mass when photons don't? Any insight in this subject is welcome. | [
"Not really. That's a commonly used analogy but it's not quite true. The electric field around electrons is modified by their presence, and those modifications behave like photons, but it's not the same as electrons emitting photons. ",
"link"
] | [
"Also two photons cannot create an electron.",
"I was under the impression that since electrons and positrons do annihilate into two photons, it must be possible for two photons (of suitable spin and energy in respect to each other) to form an electron and a positron."
] | [
"Electrons are massive charged spin-1/2 particles. Photons are massless neutral spin-1 particles, which are best viewed as quanta of electromagnetic radiation."
] |
[
"I can smell scents breathing in, why can't I smell the same scents breathing out?"
] | [
false
] | For example, sticking my nose in a scented candle jar, the smell is extremely strong, but I can't smell anything breathing it out. | [
"This is absolutely unacceptable behavior and will result in a permanent ban if repeated. "
] | [
"This is absolutely unacceptable behavior and will result in a permanent ban if repeated. "
] | [
"Your olfactory system is certainly active when you're breathing out - in fact retronasal olfaction (perception of the smell of food within the mouth) provides most of our sense of taste, and occurs mainly ",
"during exhalation",
".",
"I can't explain what you observe as not smelling anything while breathing ... |
[
"Are face muscles controlled through the spine?"
] | [
false
] | [deleted] | [
"It depends on the causes of paralysis. Speech is a complex act and a lot of different nerves are used to make it happen. It is possible that some of them would be damaged while the rest would be intact resulting in partial loss of the ability to speak."
] | [
"Just for completeness sake, there are also some muscles in the face (for chewing, primarily) that are controlled by branches of ",
"CN V, the Trigeminal Nerve.",
" But as ",
"/u/ReineBlanche",
" alluded, all cranial nerves attach to the brainstem rather than the spine. ",
"Edit: should read \"above the ... | [
"all cranial nerves attach to the brainstem ",
"CN I and II don't. "
] |
[
"Geologists: What forces caused these adjacent mountain formations to end up looking so different?"
] | [
false
] | I took this photo as I drove through the Mojave Desert near Barstow, CA. The coordinates from which I took it MIGHT be 34.766999,-115.472832 according to Google Maps (street view seems to match my photo), and I was shooting to the northwest. | [
"Looks like the darker mountains are cinder cones of volcanic origin. "
] | [
"The darker ones look distinctly mafic to me, so I agree that they're probably igneous, maybe volcanic in origin.",
"General geomorphology though makes me think these things you're looking at aren't mountains, more like rotated fault blocks."
] | [
"A fault block is just a geometric unit of rock that has been faulted. ",
"Sometimes the plane along which it has faulted is a bit curved (technical term for this is listric) and it causes the fault block to rotate as it progresses along the fault.",
"I realise I am doing a terrible job of explaining this and a... |
[
"What causes Triboluminescence, where sparks appear when glass or hardened sugar for example is shattered?"
] | [
false
] | Edit: video example: | [
"All of this is from ",
"here",
"Triboluminescence is light produced while striking or rubbing two pieces of a special material together. It is basically light from friction, as the term comes from the Greek tribein, meaning \"to rub,\" and the Latin prefix lumin, meaning \"light\". In general, luminescence occ... | [
"I did a science fair project in grade school in which I bit into each flavor of lifesavers to check whether I could see a spark (also a good excuse to eat a lot of candy). I saw sparks on each of the white minty ones (wintergreen, peppermint, etc.), but not on the sugary ones (five flavors, butter rum, etc.).",
... | [
"From what I can read, it is caused by electrical charges being separated in the breaking process(atoms being separated from some of its electrons). This causes potential build-ups which in turn causes the electrical arcing observed.",
"Basically it seems like \"static electrical buildups\" caused by the breaking... |
[
"What is the proper way to break in an internal combustion engine?"
] | [
false
] | [deleted] | [
"You absolutely, without question, want to take it easy during break-in. The length of the break-in period is debatable, and it seems to be getting very short to non-existent on modern engines. But that's beside the point.",
"The reason you want to take it easy has a lot to do with friction. Everywhere in the eng... | [
"Oh no, the feared vertical-text-super-rant.",
"The big thing here is the difference between a race engine and a everyday use engine. Race engines live short and violent lives, and are tuned to last just long enough. The article you linked is all about piston rings, and how a hard break-in gives you more power. I... | [
"I think a machinist point of view would serve better. ",
"The new engine has lots of residuals from the machining. Metal dust, and metal burrs. If you run an engine for a little while, and then change the oil, you will see all this little metal crap in the oil. It is definitely going to accelerate engine wear. S... |
[
"How do neurons do math, (like adding, subtracting)?"
] | [
false
] | From my understanding, neurons are just wires that carry a signal, and have no means of computation like the logic gates in computers. How do they do it? | [
"The signal they carry affects the transmission of signals by other neurons, oftentimes by directly activating or inhibiting other neurons. Usually the activity of any given neuron is modulated by many other neurons. While we should be careful about taking this analogy too far, these activating and inhibiting inter... | [
"I already think you're taking the analogy too far. Brains and computers share very little in the mechanics of how they function. The human brain doesn't really do math, it memorizes algorithms and certain equations (e.g. times tables) and applies them in combination with counting. Mental math is typically relia... | [
"I agree with your analysis. The brain doing math (specifically arithmetic) probably uses the same mechanisms it uses when we hit a tennis ball with a racket or drink water from a glass without spilling it. It repeats a practiced and remembered sequence of steps including math tables and how to write each number.... |
[
"How do I ensure my body goes to science?"
] | [
false
] | Hoping this won't be relevant any time soon, but what are the logistics for donating my body after I die? (I'm Already an organ donor.) | [
"When you get older and are settled in one place you can approach a university and arrange through them. Medical schools for example need bodies and are very grateful if you decide to donate your body."
] | [
"There are private companies that accept cadavers for testing medical devices (orthopaedic implants, etc), but generally they pay for all your funeral costs as their form of compensation. That does not mean they're not out there, ones that actually pay cash, but I'm not aware of any."
] | [
"Where do you live? Maybe contacting your local health care whatever and ask.\nIn Sweden (where I live) we have a national database which you can sign up for different uses of your body when you die."
] |
[
"Why does testing for Ebola require venipuncture rather than capillary blood?"
] | [
false
] | Hi folks, With the current focus on Ebola, I've struggled to understand why healthcare workers are consistently exposed to needlestick injuries when evaluating patients with the disease. Per the CDC, the . This is consistent with other guidance from the WHO and MSF. This obviously requires the use of butterfly needles/vacutainers to obtain a sample which is more dangerous (in my opinion) than using a to obtain capillary blood. Is there a reason why we need (a) this quantity of blood and (b) why couldn't we use capillary blood using for testing? The reason why I get confused is for the following reasons: Thanks for any thoughts you might have! | [
"There is a higher possibility of surface contaminants from a finger stick/capillary blood sample. Venipuncture allows you to get a more pure sample from within the body with less chance of contaminants. "
] | [
"is impervious to needles",
"Unfortunately, the gloves used by healthcare workers are not impervious to needles. ",
"The body can be pumped with antiviral drugs which quickly kills of the small amount that has entered the body. (the same treatment can be used for HIV and has ~80% success rate within 48 hours, I... | [
"is impervious to needles",
"Unfortunately, the gloves used by healthcare workers are not impervious to needles. ",
"The body can be pumped with antiviral drugs which quickly kills of the small amount that has entered the body. (the same treatment can be used for HIV and has ~80% success rate within 48 hours, I... |
[
"Does DNA regulate its own susceptibility to mutation?"
] | [
false
] | Whenever I read about all the error-checking mechanisms and programmed cell death, I always think about whether a 0% error rate is even desirable. It's not difficult to think of situations wherein a small possibility of mutation a good thing. Or is the mutation rate always too high for the genes' own good? | [
"You raise a good point, without mutations there would be no evolution and such organisms would have long since died out. There's some discussion of it at this article here: ",
"https://en.wikipedia.org/wiki/Mutation_rate",
"It's also becoming increasingly common for scientists to look for the heterogeneity of... | [
"just to clarify though, the Sun's radiation does not contribute to heritable germ line mutations"
] | [
"This paper",
" used 3gy of x-ray radiation on some mice, bred them, and then sequenced their offspring to determine rates of germ line mutation. They found increases in copy number variants and in indels - the number of single nucleotide polymorphisms was similar but the distribution more skewed in irradiated mi... |
[
"Why is HIV the Vector of Choice for Gene Therapy Treatment?"
] | [
false
] | [deleted] | [
"Lentiviruses like HIV are popular backbones for gene therapy vectors for a few reasons.",
"The first is that they integrate into the host genome, permanently modifying target cells and enabling long-term correction of genetic defects. Most viruses do no do this, and are thus only capable of transient transgene ... | [
"HIV is a member of the genus of viruses called Lentiviruses. Modified ",
"lentiviruses",
" are very useful in the lab because they can infect non-dividing cells (most retroviruses can only infect dividing cells), and once they integrate into DNA, all daughter cells will also express the gene (or whatever) of i... | [
"Hey could you post some resources going into detail about transdusing non-dividing cells? That seems really interesting and I'd love to know more in depth about it."
] |
[
"Is any atom truly stable in terms of radioactive decay?"
] | [
false
] | Given there are atoms with half lives of billion of years, it it possible that all atoms decay, just over such large periods of time that they cannot be observed? | [
"This is something that theorists grapple with. There are limits to what we can observe, experimentally speaking. Some isotopes are predicted to be unstable with extremely large half-lives, such as ",
"iron-54",
" (with a half-life of ~10",
" years). Yet it is almost impossible to measure such a minuscule ... | [
"I guess it's just a matter of semantics, but I tend not to include proton decay considering that there is no experimental evidence (despite decades of looking) and it is only even predicted to occur by some theories."
] | [
"Of these, 90 have no predicted modes of decay, so theory would say that they are stable across all time.",
"They have no modes of decay which we have observed, but there are many theories that allow for ",
"protons to decay",
" in violation of ",
"baryon number conservation.",
" These could provide an a... |
[
"Can fingers regrow their unique prints after having a chunk cut off?"
] | [
false
] | How similar would it be? What if there were previous prints taken? | [
"To add to that, you won't get new fingerprints. You'll destroy the fingerprints that you have, which will have a negative impact on your ability to grip things"
] | [
"The structural information that determines the shape of your fingerprints is present in the dermis, which is the layer of skin just beneath your epidermis, which is the outer layer. Ridges/folds called dermal papillae exist at the boundary of these two layers and from these arise the prints. If you damage the derm... | [
"Huh... never before have I thought of my fingerprint as a grippy pad, lol."
] |
[
"Is a planet with an eliptical orbit slowly adjusting to a circular orbit?"
] | [
false
] | Is a planet's orbit determined by its trajectory when getting caught by a gravitational pull? Does it slowly balance itself out like when you drop a marble in a sink? | [
"In a two-body problem like gravity, in bound orbits (circles and ellipses), the semimajor axis ",
" and the semiminor axis ",
" of the orbit are given by",
"a = -GMm/(2E)",
"b = L",
"/sqrt(-2uE)",
"where G = gravitational constant, M = mass of one body, m = mass of the other body, E = energy, L = angul... | [
"Ah, thanks. I corrected the language. I also changed the part about the velocity being initially tangential to the surface directly below you. That actually puts an extra constraint on the orbit, namely that where you magically appear is either apogee or perigee. I would rather just consider magically appearing an... | [
"Some of this does not make sense. If you've got less than escape velocity, you are automatically in an elliptical or circular orbit. You don't have to fall before the orbiting starts - the \"falling\" is just part of your orbit. It could be a ground-intersecting orbit, but it's still an ellipse. Your starting ... |
[
"How does one determine how much water can be absorbed by different compositions of the ground?"
] | [
false
] | Such as how much water can soil vs sand absorb, and how do we determine this? Say you have a patch of desert and water steadily dripping at a constant rate. How much of the ground would the water penetrate, get soaked up essentially, and at what radius? Additionally, how long would it take to convert the sand to soil? | [
"Those are some pretty broad questions. In a simple experimental set up, (i.e. dripping water at a set rate on some homogeneous material) you could probably get a reasonable answer to your question with ",
"Darcy's law",
", but generally the answer will depend on the porosity (how much of the material is void s... | [
"I'm going to read this again tomorrow to make sure it all sinks into the noggin.",
"I've been wanting to do an experiment where I basically have water drip for a period of time over a patch of ground.I figured I could test with 100% sand and then test it with different compositions of earth and maybe compost. Or... | [
"Permeability of the composition in question and how much room there is. Also to some degree the water itself, which is not likely pure in this scenario, as differences it it's composition can effect is surface tension among other things and might change the result. I could get all technical but that's the gist of... |
[
"Got a question about mirrors...."
] | [
false
] | So, if there was a mirror placed one light year away facing earth could we see back in time two years later if we looked at the mirror? Also, if we some how projected the earth to the mirror for a year and then replaced this projector for another mirror, could we preserve that memory for eternity? | [
"I don't understand the second question, but the first is a \"yes... but\" kind of answer. The 'but' is ultimately engineering concerns like telescopes that could have infinite resolution to be able to perceive the earth in the mirror's image. Remember that if the mirror is a light year away from the earth, the ear... | [
"As to your first question: In principle yes, but in practice no. Light falls in intensity by the square of the distance traversed. We'd see nothing but a dim smudge.",
"As to your second question: There's no such thing as a perfect mirror. Light that's reflected is scattered and absorbed in various proportions d... | [
"Light falls in intensity by the square of the distance traversed. ",
"This assumes that the light is diffusing outward in many directions. I'm not sure what OP meant with \"if we some how projected the earth to the mirror\", but a laser projector would not follow the inverse square law because all the light is m... |
[
"Why are sulfonamides not considered antibiotics, but rather antibacterial agents?"
] | [
false
] | null | [
"Most infectious disease doctors are actually moving away from the term antibiotic due to its generic naming. ",
"Anti (against) bio (life), could in theory mean anything from anti-viral, anti-bacterial, anti-parasite, anti-human, anti-dog. ",
"You’re starting to see a conversion of terminology away from antibi... | [
"\"Antibiotic\" in its strict medical definition refers to naturally-occurring things, or derivatives thereof. Macrolides like erythromycin came from Saccharopolyspora, penicillins from Penicillium, cephalosporins from Acremonium, etc.",
"Sulfonamides are totally synthetic, so often they are classed differently."... | [
"So without getting too deep, my understanding would be that all bacteria are microbes, but not all microbes are bacteria. ",
"So in the discussion of terminology, anti-microbial is less precise than anti-bacterial."
] |
[
"Does rinsing or just running water over my hands without soap after using the bathroom do anything?"
] | [
false
] | Does it add any germs or rinse any off without the soap to encapsulate the germs? | [
"I dont think that rubbing your hands together will kill bacteria. They are too small to unfluence that way. \nAbout the hot and cold water. You would need to put your hand in boiling water for an extended amount of time (hours) before it even remotely kills enough bacteria to be considered clean. And switching bet... | [
"Hypotheically, would quickly changing the water from very hot to very cold in a short amount of time possibly kill bacteria? Shearing aside. "
] | [
"Hot water might kill some germs (but I wouldn't depend on water that hot not scalding you) and rubbing your hands together would break some of the bacterial cell walls through mechanical shearing. I would still use soap though"
] |
[
"Homemade light bulb"
] | [
false
] | Hi there askscience! Im working on a homemade lamp project, and have decided that what id really like to do is create a home made lightbulb using a spirit bottle as the glass. I've had a look on google, and found guides to making bulbs, but they all seem to be small scale science projects, in which the filament fizzles out really quickly, as a result of not being properly sealed. So i have a few questions, 1: what sort of gas would be best, i assume helium is easiest, but by its nature would escape the bottle easily. 2: would a tight rubber seal be enough to prevent the gas from escaping, or should i use something like an epoxy resin, which would of course mean the seal was pretty permanent (it'd) be nice to be able to open and close the bottle to replace the filament. 3: will i be able to break open another bulb and use its filament etc, or should i make my own with tungsten wire? I want the filament to be as crazy looking as possible (like a vintage bulb), but this will obviously require allot of trial and error Advice for any of these questions would be greatly appreciated! | [
"I thought about making a vacuum, but i figure that air pressure will eventually make its way through watever seal i use. Id like to get it to work for 1000+ hours"
] | [
"I know that carbon filament bulbs were used back in the days that lightbubs were invented, they work quite well under poorly drawn vacuums. ",
"If you put the bulb in a bag and connect that with a vacuum cleaner, it should pull out enough to actually work. (Ofc this depends on your vacuum cleaner and the seal on... | [
"If you seal it off correctly then it should stay good. Air can't leak in that easily. You can make partial vacuums with normal plastic bottles and keep them that way by screwing the lid shut. (The only problem is that they collapse under the pressure, glass bottles should do fine though.)",
"Bottom line, I sugge... |
[
"Why did primates evolve to not internally manufacture an essential vitamin, vitamin C, whereas other herbivorous, carnivorous and omnivorous species did not lose this trait?"
] | [
false
] | I understand that we ( homo sapiens sapiens, and other primates) rely on consuming animals and plants that create this vitamin themselves, however, why has natural selection singled us out and (for all intents and purposes) caused us to not produce it ourselves? Why haven't herbivores, which eat flora that is vitamin C rich lose this trait? Same thing goes for carnivores, which eat other fauna (which contain vitamin C themselves from either flora or other fauna)? Since it is an essential vitamin, and can cause a myriad of problems if there aren't sufficient quantities of it in our body, why have we evolved to not produce it when other animals haven't? NOTE: I am presuming that the ability to produce this vitamin was present earlier on in our evolutionary timeline (hence why the vast majority of living things have the ability). If this is incorrect (ignore, otherwise), then a similar question: Why are we one of the very few species to not develop this trait, yet? Thanks guys! :-) | [
"The ancestors of old world primates lived in an environment that was abundantly rich in vitamin C in the form of citrus fruits. In this environment, being able to produce vitamin C didn't matter and genetic drift lead to it being removed from our genome. It only causes problem for human because the have spread out... | [
"We didn't lose the genes. We still have them, in fact the first 3 out of 4 work but the last ",
"isn't active",
"."
] | [
"There is no purpose to the evolution. The lack of biosynthesis of Vitamin C was caused by a genetic mutation on GLO gene which causes an enzyme not to be produced for the biosynthesis. What this tells us is that the mutation happened in the common ancestor of all extant anthropoids. It was not selected against bec... |
[
"Leishmania is a parasite that targets immune cells. Why is it less dangerous than HIV?"
] | [
false
] | Leishmania is a protozan parasite that attacks immune cells and causes leishmaniasis. Since it also damages the ability of the immune system to protect against infection, why is leishmania less dangerous than HIV? Does it have something to do with the speed at which leishmania can reproduce? Why is there an AIDS pandemic but not a leishmaniasis pandemic? Since leishmania can infect vertebrates and be spread by insects (and HIV can only infect humans and can't be spread by insects), what makes leishmania less infectious than HIV? What makes leishmaniasis an easier disease to treat than AIDS? Does the immune system have any defenses against leishmania? If left untreated, what are the chances that someone infected with leishmania will recover? | [
"Leishmaniasis (called L- from here on out) prevalence largely depends on the prevalence of the sand flies that spread it. While technically it can be spread sexually [1], people with visceral L- are not generally in a condition to be having sex. Therefore, it doesn't spread too well as an STD. Meanwhile, HIV is an... | [
"HIV is a retrovirus, meaning it inserts its genetic code into the host cells. So not only do those cells make the virus, but all their descendants will, as well. This makes HIV almost impossible to eradicate from the host. ",
"We have drug treatments for leishmaniasis which are extremely effective, and once it’s... | [
"Awesome reply, thank you!"
] |
[
"How does reflection on the water surface work on the atomic level?"
] | [
false
] | If a photon hits a mirror, the angle of incidence is the angle of emergence. This alone is remarkable because if you think of the photon absorption and emission of atoms one would think that the photon is absorbed and then emitted in a random direction. One would also think that not all frequencies are allowed. However, we know that mirrors can reflect with almost 100% efficiency. It is usually argued that due to the high symmetry of the crystal in the mirror the photon actually couples to highly symmetric excitation and this leads to the fact that light is reflected according to Snell. If the symmetry of the surface is crucial then I wonder how the water/air surface can act as a mirror? In the limit of total reflection all the light is reflected and the angle is exactly the expected one. My conclusion is that this means that water at the water/air interface is highly structured like a crystal. Ideas? | [
"I'm not sure of the physics of reflection but scattering can occur when the electric component of light causes temporary polarization of the electrons orbiting an atom. ",
"The added energy promotes the electrons up to a virtual energy level which quickly returns to a lower, real energy level. The wavelength of ... | [
"Thanks for your reply.",
"I can understand the Huygens-Fresnel model which is also mentioned in the wiki link you gave. There, the emergent wave is built up from many small excitations at the surface. This however only work when the surface is highly isotropic, also on the atomic level.",
"Therefore my questi... | [
"So you assume that water particles alone (without salt) do have this isotropy at the surface. My question is whether this is true. ",
"I think it is (based on the reflection argument) but have found no reference. ",
"Let me reformulate the question: How does water look like at the surface?"
] |
[
"Evolution Debate"
] | [
false
] | null | [
"Nothing in Biology Makes Sense Except in the Light of Evolution - Theodosius Dobzhansky"
] | [
"Laboratory Observed Speciation",
"A starting point for objections to evolution",
"Nylon-eating bacteria",
" The latter being interesting in that it has apparently evolved enzymes only useful for digesting nylon products, which are not only different from its relatives, but also which would have also obviousl... | [
"Evidence of common descent",
"\n",
"20+ evidences for evolution",
"\n",
"A website with a load of links supporting evolution"
] |
[
"How do astronomers tell the difference between a cooler, red star blue shifting towards us, and a hotter blue star red shifted away?"
] | [
false
] | Is it based on the general shift of the local group the individual stars are a part of? Or do spectral lines become shifted as well? | [
"The doppler-shift is measured using spectral lines. Certain spectral lines show up in certain positions that are well known. Doppler-shifting shifts the position of the spectral lines. So by comparing the distance between the measured position of the spectral line and the position where it would be without the dop... | [
"First of all, a hot O star and yellow G star like the sun, and a cool M star have dramatically different spectra from one another. ",
"For example, the D lines of neutral sodium are very prominent in the spectra of cool M stars, but weaken quickly through the hotter K and G classes. The Hydrogen-alpha and beta... | [
"The spectral lines are shifted by relative motion and the expansion of the universe only. Their position does not depend on the temperature. You can shift that back to get the original spectrum, and then see how much infrared/red/blue/ultraviolet/... the star emits overall. That gives you the temperature."
] |
[
"Why Do Most People Root for the Underdog?"
] | [
false
] | Hundreds of movies and books, as well as personal observation, lead me to believe that most individuals root for the underdog when they don't have a vested interest in the outcome. Why? Has it been studied? If so, has there ever been a correlation between the tendency or lack thereof and normal vs. abnormal psychology? | [
"Researchers generally assert that we love to root for the underdog out of a general sense of fairness and justice for the disadvantaged, and that we perceive underdogs to be putting in more effort than the top-dogs, so we feel like they deserve to succeed.\nA recent study looking at who people tended to support in... | [
"Thank you. For some reason this reminds me of the \"protestant ethic\": perception of spiritual salvation for those that deserve it by living a life of hard work and humility. "
] | [
"It's worth noting that this is a cultural phenomenon as well. I suspect this has something to do with the number of underdog-based movies that the average Western-cultured person sees as a child.",
"There are some cultures -- notably in Korea and China -- where people tend to \"root\" for those that are actually... |
[
"Did an X20+ solar flare actually just happen?"
] | [
false
] | null | [
"No it appears there was an error on that table. It now correctly states: ",
"\n",
"\n"
] | [
"I'm not super familiar with this stuff, but I'm not seeing anything of that magnitude on ",
"NOAA's SWPC",
"."
] | [
"I'm not sure where you're seeing that, perhaps you're misreading the graph. The most powerful flare recently has been X3.2-class."
] |
[
"If humans(and other animals) have bilateral symmetry, how are certain organs (like the heart and liver) not symmetrical?"
] | [
false
] | I had this thought today. Obviously many things are symmetrical, such as two lobes of the brain, two kidneys, two lungs, but not everything. Why are the single organs not in the exact center of the body or not symmetrical side to side? I'd love any explanation, or some one two explain how I might be misunderstanding organ symmetry. edit: "are" not "our" | [
"The gist of the problem for asymmetrical organ development is left-right axis formation. We know a lot about antero-posterior and dorso-ventral axis formation, but left-right is less well understood. It is possible to deduce left and right if you already know which way is up and which way is forward. What we do kn... | [
"am I correct to take the reading of that diagram to imply that the heart system starts development symmetrically, but through twisting and moving, finally forms asymmetrically?",
"yes.",
"I realize now that my explanation isn't that clear. The short answer is: ",
" which are chemicals being produced in regio... | [
"very interesting diagram. I'll admit, I don't fully understand everything you're stating. Regardless, am I correct to take the reading of that diagram to imply that the heart system starts development symmetrically, but through twisting and moving, finally forms asymmetrically?"
] |
[
"At the most fundamental level, what stops me from falling through the floor?"
] | [
false
] | To my knowledge, it's only the electromagnetic force. But I don't understand that. If you could generate a strong electromagnetic field through some method - wouldn't it be impossible to walk through it? Would it feel like wall? How does this work? Edit: | [
"Actually, your second explanation is most likely right.",
"http://en.wikipedia.org/wiki/Pauli_exclusion_principle#Stability_of_matter",
"\"As described by FJ Dyson (J.Math.Phys. 8, 1538-1545 (1967) ), Ehrenfest made this suggestion in his address on the occasion of the award of the Lorentz Medal to Pauli.\""
] | [
"I think the most common explanation is electromagnetic. My electrons repel the electrons in the wall/floor and thus we can't pass through them.",
"But I had a professor in undergrad that swore it was the Pauli exclusion principle at work. My electrons can't occupy the same space at the wall/floor's electrons. ",... | [
"This question comes up a lot",
", and most people come up with the intuitive idea that the answer is the electromagnetic force, since the inverse square nature of the force means the force goes to infinity as the separation distance goes to zero. Except you'll also notice that no one even tries to offer an actu... |
[
"Is there any advantage in our DNA being coiled into a double helix?"
] | [
false
] | Could also just be a side effect of the intrinsic DNA structure, but I suspect there might be some advantage to it? (rigidity? chemical protection?) Thankyou | [
"I think 'all the above' would work as an answer here. ",
"DNA bases (deoxyribonucleotides) are synthesized (by ",
"Ribonucleotide reductase",
") from ribonucleotides, those used as bases in RNA. Which is one of the reasons the dominant theory is that ",
"RNA evolved first",
". ",
"Unlike DNA, RNA is si... | [
"Excellent summary. I would only add that the regular double helix structure also provides simultaneous data density and data access. Long strands of RNA can be a horrible mess, with parts annealing to themselves and twisting into complicated 3D shapes, while DNA, with the ",
"2' hydroxyl",
" missing, will fold... | [
"A couple reasons: Size, chemical protection, and readability by proteins.",
"DNA is actually coiled multiple times",
". this supercoiling allows for space conservation inside cells. A fully uncoiled human genome in a cell would be a meter or two in length. This isn't directly associated with the double-helix n... |
[
"What is the best form of iron to take as a supplement for someone with iron deficiency anemia?"
] | [
false
] | [deleted] | [
"Heme iron (the iron in blood) is readily absorbed, so- red meat. Iron salts (such as the iron sulfate mentioned above) are poorly absorbed; the iron in breakfast cereals is frequently found as iron filings (!); it's a classic lab demonstration to put a beaker of water on a stir plate with a magnetic stir bar and a... | [
"Yeah; SP is a very pricey line, with some sketchy distributors.",
"I would suggest you find a good source of organic beef liver, and try that. I can't stand the stuff, but smothered in mayo, it's tolerable."
] | [
"Yeah; SP is a very pricey line, with some sketchy distributors.",
"I would suggest you find a good source of organic beef liver, and try that. I can't stand the stuff, but smothered in mayo, it's tolerable."
] |
[
"Since the rotation of the earth is slowing down, when will the day be twice as long as now?"
] | [
false
] | [deleted] | [
"Unfortunately, it's not a strictly linear figure that can be easily calculated out. There are, for instance, forces which accelerate the rotation of the earth, or slow it differently, than just the tidal interactions with the moon. For instance, the Indian Tsunami may have accelerated the rotation of the earth by ... | [
"According to Wikipedia",
", one day is now longer by 1.7 miliseconds than it was about a hundred years ago. That is 0.0017 secs in 100 years. One day is 86 400 seconds.",
"86 400/0.0017 = ~50 823 529.411",
"50 823 529.411 * 100 = 5 082 352 941.1",
"That makes 5 billion years."
] | [
"The sun doesn't have enough mass to die by supernova, but will go through a nova and shed its outer layers, leaving a white dwarf. This is after it expands near to the Earth's orbit, but not quite. It will absorb mercury and venus, however."
] |
[
"How do you grow \"seedless\" watermelons?"
] | [
false
] | null | [
"You use a chemical called colchicine, which prevents cells from dividing by only letting their nucleus divide, not the citoplasm. It's called karyokenisis without cytokenisis. This leads to a tetraploid, an organism with four sets of chromosomes.",
"Plants are quite a bit more flexible than animals. They can sur... | [
"This short article explains it pretty well.",
"Basically, you breed triploid plants so they are not so good at making seeds."
] | [
"You use cultivars that have seeds that mature late in development. Using this method you get water melons that have seeds, just not big, hard black ones. Because you don't want big hard black ones in your mouth. "
] |
[
"What material and what speed would an asteroid-comet need to pierce a planet and exit the other side? xpost from /askreddit"
] | [
false
] | My gut says this isn't possible based on compression and densities deep within planets combined with the pulverization of the object crashing into the planet. But here's hoping... Let's keep our planet choices to ones in our solar system, Pluto and major moons also count. No made up minerals like adamantium or borg ablative armor. Real physics please. I'm merely interested, and certainly not working on any doomsday devices this week. Totally hypothetical scenario based on a CGI image It comes from this blog of other | [
"Consider the forces an asteroid would encounter when it smashes into solid rock. There will be inertial forces, i.e. forces required to physically accelerate rock, and mechanical forces (stiffness, pressure etc.) to deform the rock. The mechanical strength of both the Earth and the asteroid will be roughly constan... | [
"You're confusing physics with minecraft again."
] | [
"You're confusing physics with minecraft again."
] |
[
"What happens to competing virus variants in a given area?"
] | [
false
] | So I'm not sure exactly how to word the question, so sorry in advance. We keep hearing about new variants if the Covid virus (the UK, South Africa and Brazilian variants). They are all reportedly more transmissible and are becoming the dominant variant in the areas they were discivered. What happens if there is an equal prevalence of each variant in a given area? Do they mutate further to try and gain dominance? What governs that? Finally is there any benefits or negatives to the human population in those areas (having a virus compete for dominance)? | [
"Hey! Mutations are not something the virus can activly switch on to battle other viruses. Mutations are the result of errors during the virus replication. As far as i know they don't have the same proof reading mechanisms we have. So think of it like copying a long text by hand. You'll make errors. Youre cell mach... | [
"The brilliant evolutionary biologist Richard Dawkins put it like this: nothing really wants to mutate. Mutations are just something that happens and that you are forced to work with. Some viruses are better at mutating (i.e., worse at correcting errors) than others. Some are bad at this by design. In our bodies, m... | [
"Hey, thank you for the detailed reply!"
] |
[
"What chemical is this? (PIC)"
] | [
false
] | While cleaning out the high school chemical storage, I found glass tubes. Before I pay someone to dispose of them, I wanted to know what they are. I would guess that it is either Bromine gas or Nitrogen Dioxide gas. And I don't know what the clear tube is. It's possible it's empty. I remember a demo that showed a decomposition of NO2 when heated. I could try to heat the tube up and see if it turns colorless, but would that be enough to know for sure that it's NO2? tl;dr What's in glass tubes? | [
"Why not do some spectroscopy to find out? "
] | [
"It's pretty difficult to tell, but I'd lean strongly towards bromine, if only because that's a more common classroom example at that level. If the other one has gas in it, I'm guessing it'd be some noble gas. Perhaps Neon or Krypton since they're a bit more 'exotic'.",
"I wouldn't heat it though, too big a risk ... | [
"I was also afraid of the glass cracking, I would have done it in the fume hood though. I did not think that bromine was a more common classroom example, but then again, there is some old stuff in there so who knows. I found a glass jar(like a jam jar) with a chunk of sodium in it. Extremely oxidized.",
"I'll ... |
[
"What does a monogamous bird do when his partner die ?"
] | [
false
] | null | [
"It should first be noted that many birds exhibit \"serial monogamy\" in which the mating pair is faithful for one season, but may choose different partners the following season.",
"There are indeed long-lived birds that are described as mating for life, but in the two examples I can find explicit answers for, th... | [
"I've seen similar rumors. There are certainly documented cases of female albatrosses, well old enough to be mating, joining a gathering during breeding season but then leaving without having ever mated. It is speculated that these females have lost their mate.",
"However, I could not find any solid scientific ev... | [
"I've seen similar rumors. There are certainly documented cases of female albatrosses, well old enough to be mating, joining a gathering during breeding season but then leaving without having ever mated. It is speculated that these females have lost their mate.",
"However, I could not find any solid scientific ev... |
[
"How do archaeologists/anthropologists determine the sex of human remains (not limited just to skeletons)?"
] | [
false
] | Also, presuming there are different methods, how relatively reliable are different methods? Also, if there is a mismatch between the presumed sex of bodily remains and the presumed gender signaled by any burial goods found with the remains, how is this usually interpreted? | [
"That's a hard one to answer succinctly. There are lots of different physical characteristics that are unique to males and females, but they are variable dependent on race, environmental factors, age etc. (As an example it is near impossible to differentiate sex in child skeletons, and some races have more delicate... | [
"I wrote a blog post on this recently: ",
"https://namuhyou.wordpress.com/2016/06/18/sexism-when-sexing-your-skull-cultural-bias-when-sexing-the-skull/",
"The best way to interpret sex is by the pelvis. If this is not available then you have to use what is available. Some researchers argue to use post cranial r... | [
"I would argue that all humans do have an external occipital protuberance as it is an attachment site, rather it is the robusticity that is in question. Walker (1994) instead uses the term nuchal crest to look at sex, which is a probably a better term to encompass occipital rugosity. ",
"The skull is arguable for... |
[
"Are rogue planets more spherical than planets that are orbiting a star?"
] | [
false
] | I was watching kurzgesagt's video about potential life on rogue planets (which is a great video: ), and it mentions the formation of these types of planets. However, it doesn't mention this essentially mundane question of mine. Could rogue planets be more spherical than planets that are in an orbit because they have a potentially less uniform rotation? I could understand that there's no way we could really accurately measure this and it's pretty useless information, but I was just curious if anyone had an idea. Thanks! | [
"The spericalness is mainly driven by the total mass of the object. The higher the mass the more spherical as surface gravity is highest. For this reason we see the largest mountain in the solar system on Mars and smaller bodies like moons or dwarf planets are even less spherical."
] | [
"That makes a ton of sense. I didn’t think about that, thanks! Would having a higher mass of orbiting moons effect the sphericalness as well? Or if the planet has a hot core? "
] | [
"A moon generates tidal forces and can massage a planet a bit ..in the end helping with smoothing it out. \nUnless they are fully tidal locked, meaning both bodies face each other with the same side. Then you will get two elongated bodies. Our moon for example is tidal locked to Earth this is why we see only one si... |
[
"Movies The Matrix and Cloud Atlas take place in a reality where the dead humans are liquidised to feed the living. How sustainable is this system?"
] | [
false
] | null | [
"Hi theshantanu 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... | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScienceDiscussion",
"Please see our ",
"guidelines.",
"If you disagree with this decision, please send a message to the moderators."
] | [
"Okay thanks, I'll post it there."
] |
[
"Physically am I made up of the same atoms I was 7 years ago or am I essentially all new atoms, following the same chemistry structure of my DNA?"
] | [
false
] | Essentially What I am asking is, is the building blocks of who I am(atoms) in constant flux? How long on an average would a single atom be in my body before being lost to my environment. Physically am I made up of the same atoms I was 7 years ago or am I essentially all new atoms, following the same chemistry structure of my cells? | [
"However if you were to tag a certain bio molecule with a stable, but distinct isotope of one of the atoms in that molecule, the spirit of the question is if that molecules would move around or not.",
"The answer basically becomes \"depends.\" Some things are recycled continuously, others stored for long periods ... | [
"Wikipedia is a terrible source and the science on neurogenesis has been rapidly growing since the articles cited in that wiki were written. It is becoming a generally accepted idea in neuroscience that the brain is constantly replacing neurons through neurogenesis and there a many very well designed studies that e... | [
"Wikipedia is a terrible source and the science on neurogenesis has been rapidly growing since the articles cited in that wiki were written. It is becoming a generally accepted idea in neuroscience that the brain is constantly replacing neurons through neurogenesis and there a many very well designed studies that e... |
[
"What happens when teleported particles/states collide?"
] | [
false
] | null | [
"No, because quantum teleportation is not taking a bit of matter and somehow getting it to a remote place.",
"In quantum teleportation, the process is that Bob manages to turn a particle in his possession into the state that one of Alice's particles previously was in. Bob cannot simultaneously turn his particles... | [
"I think you are misunderstanding the way that this 'teleportation' occurs. You can't 'send' quantum states to the other particle as that would violate the speed of light. Instead the way to look at it is that two people are observing the same event remotely. Collapsing one part of the entangled system collapses... | [
"you cant teleport 2 states to the same particle at the same time by definition of teleportation , since measurement is involved. the details are complicated thought, usually grad level physics "
] |
[
"Can the NeverWet superhydrophobic spray be applied to wood to seal in moisture and make it fire proof as a result of the Leidenfrost effect?"
] | [
false
] | null | [
"Nope, superhydrophobic doesn't mean air-tight, which means that water vapor can escape and will have its limits as an insulating layer. However, NeverWet is silicon-based and might confer some fire-resistance (though not much with something so thin)."
] | [
"The Leidenfrost effect is when you dip your fingers in molten lead just for a second, and the heat from the lead instantly vaporizes the moisture in your finger thus creating insulation from the heat protecting your finger. ",
"Have it a little wrong here - you dip your finger in water ",
" The moisture is not... | [
"The thing is, the water dissipating is what keeps your hand from getting burnt in the first place. The phase change from liquid water to steam uses up the energy that would be denaturing the protein in your fingers.",
"If you did have some kind of glove to trap the steam in with your hand (A hydrophobic spray wo... |
[
"Infinite series question"
] | [
false
] | If you have an infinite series that has a term in it that divides by zero, does that make the series diverge? Ex.) If you have the infinite series cos(pi*n) / (sqrt(n) - 3)), starting from n = 1. When n = 9, you're adding a term that divides by 0, does this make the alternating series diverge, regardless of whether tests say it converges conditionally? tl;dr The definite of an infinite series is S = a_1 + a_2 + a_3 .... a_n. What happens when one of those terms in the infinite series divides by 0? | [
"It's not that the series is divergent - it's that it literally does not represent a value. A series as a concept is just a sum, right? But if part of that sum is something that does not have a value, then your sum is non-sensical, right? If I say \"what's 1 + 3 + purple + 5?\" there's not really an answer to that.... | [
"The series is undefined for n=9 which usually implies there was an assumption in the derivation of that series that was not valid for n=9. How to handle this depends completely on what the series represents.",
"For instance if you were to develop a ",
"sin series",
" for sin(x)",
" you would end up with a... | [
"If the series has a term which divides by 0 then the series is undefined. Basically the series doesn't exist in the form you have given it. ",
"It can mean a lot of different things depending on where the series came from. You have to give the context of what the series is in order to derive any meaning from ... |
[
"I am a resident of Miami, Florida and my mom is convinced the entire city will be underwater in 25 years. While I know this is false I don't have any evidence to back up my claim. Can someone knowledgeable on the subject tell me why this is false and at what time Miami will be underwater?"
] | [
false
] | null | [
"Current sealevel projections for the next 25 years forecast a rise in the order of 10 to 25 cm (see ",
"Horton ",
", 2008, figure 1",
"). The predicted rise over the next century is somewhere between 40 cm & 1 m.",
"On the other hand, maps of parts of Miami which are susceptible to flooding show that some ... | [
"I thought water was the only element that wouldn't expand with heat but with cold.",
"You are confusing 2 things:",
"Thermal expansion is a property of liquids, heat them and they expand slightly - over oceanic volumes, it is a measurable effect",
"What you are referring to is the density of ice (I THINK) - ... | [
"In a rise of a few inches will make storm surges and hurricane flooding worse. Never mind tides."
] |
[
"If I pour bleach in my toilet bowl, will it react to the ammonia in my urine and create chlorine gas?"
] | [
false
] | [deleted] | [
"If you were a fish or had kidney/liver problems and produced significant amounts of ammonia in your urine, yes. \nIf everything is working alright, your kidneys should be converting nitrogen to urea (",
"http://en.wikipedia.org/wiki/Urea_cycle",
") which shouldn't react with bleach fast enough to be noticeable... | [
"Absolutely. I have at least one friend and several acquaintances who have been hospitalized for this.",
"http://en.wikipedia.org/wiki/Sodium_hypochlorite",
"Search for \"urine\" in the wikipedia article."
] | [
"The reaction of bleach and ammonia isn't a simple one; a lot of different compounds are produced, and chlorine is one of them. You'll get some chloramine and hydrazine in the bargain, as well."
] |
[
"Would we be able to help the Helium gas depletion by using a lot of alpha emmiters to generate more helium?"
] | [
false
] | I know they don't have electrons but I assume the could be introduced somewhere in the production process. Also, I heard on Colbert that there is no natural source of Helium, wouldn't alpha emmiters create helium in the environment? | [
"This is where all our helium comes from. Alpha decay of uranium/thorium/etc in earth. "
] | [
"If the ITER fusion reactor (or any other H-based fusion) ever gets running, that should give us a decent source of helium."
] | [
"True, a 1 GW fusion reactor would only give you about ",
"75 kg of helium per year",
".",
"But my understanding of tokomaks is that you have to remove the helium to keep it from poisoning the fusion reaction, and that this is done with a diverter of some kind."
] |
[
"How does a computer know whether a number is negative or not?"
] | [
false
] | null | [
"To add to what ",
"/u/aecarol1",
" has posted, there are two ways the computer can keep track of this information:",
"1) The data type can be stored in the computer program.",
"2) The data type can be stored with the data.",
"Option (1) is the most common for low-level programming. Assembly instructions,... | [
"Yes, subtraction is almost always used and the branch simply decides what kind of compare was meant. For many RISC machines, the compare and branch is often the same instruction as some architectures do not have condition codes. Assuming you have the typical flags of (C)arry, (Z)ero, o(V)erflow, and (N)egative, my... | [
"Yes, subtraction is almost always used and the branch simply decides what kind of compare was meant. For many RISC machines, the compare and branch is often the same instruction as some architectures do not have condition codes. Assuming you have the typical flags of (C)arry, (Z)ero, o(V)erflow, and (N)egative, my... |
[
"What was the vital force in vital force theory of organic compounds ?"
] | [
false
] | null | [
"The vital-force idea was that there was \"something\" about living things that was necessary for the creation of organic substances, and that without that \"something\", it was not possible to create those substances. ",
"But no-one really knew what that \"something\" was -- it was more of a spiritual belief tha... | [
"If you don't get an answer here, you can also try ",
"/r/askhistorians",
", ",
"/r/historyofscience",
", ",
"/r/philosophyofscience",
", or ",
"/r/historyofideas",
"."
] | [
"For more information on this and a fun read, check out Life's Edge by Carl Zimmer"
] |
[
"Could domestication be considered a miniature model of evolution?"
] | [
false
] | For example, we know dogs came out of wolves. Despite today having a ton of breeds of dogs, they used to breed for purpose rather than look and even then were much different looking. | [
"Essentially, artificial selection is still the same as natural selection, just with humans forming a very strange and dominant part of the creature's environment. It still follows the same rules as natural selection in that the organism has to survive long enough to produce viable offspring, but there are more fa... | [
"Yup. Darwin spends a considerable amount of time speaking about domestic breeding programs. They prove that characteristics are hereditary and manipulable. I really recommend reading \"On the Origin of Species\". It can get a little dense, but the result is a pretty solid case for evolution."
] | [
"The Dawkins narration of the audiobook is amazing and makes it much easier to digest, IMO. "
] |
[
"Multiple questions about Gamma-Ray Bursts. How dangerous are they to Earth?"
] | [
false
] | Would we be able to detect a Gamma-Ray burst heading towards Earth before it hit Earth? If so, how far in advance would we be able to detect it? What could we detect? Spread, size, amount of time it would hit Earth for, etc.? What is the maximum range for a gamma-ray burst to pose a threat to Earth? I've read 200 light years is a conservative estimate. What are the main threats to Earth? I've read so far that destruction of the Ozone, and Stratosphere would occur, which would lead to changes in the Earth's atmosphere, which would lead to increased cloud cover and permanent winter. For the side of Earth directly hit by the gamma-ray burst, would the people be killed immediately? Or would it be just enough radiation to make it a slow death, or just disfigured for life? Thanks, I am not a scientist, but I found some literature that talked about this, and found it incredibly fascinating. Unfortunately the information regarding my questions seemed very limited. And since I don't have the math or science skills necessary to do the equations myself I thought I'd ask for help here. If you can point me in the direction of any useful articles, books, or text on the matter I'd appreciate it as well. Thanks again! | [
"1. Would we be able to detect a Gamma-Ray burst heading towards Earth before it hit Earth?",
"No, but with a pretty big catch. ",
"They don't come from nowhere. It would be impossible to detect something coming at us at the speed of light, but we'd know it was coming thousands of years in advance from observin... | [
"How long does a gamma ray burst last? Is it an instantaneous thing or does it last hours/days/months/years? "
] | [
"Short GRBs are less than 2 seconds. These account from about 30% of GRBs we've detected. Ultra Long GRB's are over 10,000 seconds, and are exceptionally rare. The other 70% are called Long GRBs, and are inbetween the above two types, although they tend to the shorter end of that scale.",
"Basically, if a GRB ... |
[
"Is Dark Matter differently distributed than regular matter?"
] | [
false
] | For instance, do we have any examples of gravitational lensing or other phenomena that could be attributed to the presence of Dark matter that don't feature normal matter? Or does Dark Matter exist pretty much i parallel with where we observe regular matter? Or am I just interpreting it all wrong? | [
"On a very large scale (galaxy groups), you'll find dark matter where you also find normal matter, because one of the things we need dark matter for ",
" to explain the formation of galaxy groups. But if you zoom closer, you'll see that rather than forming complex structures like galaxies, and within them relativ... | [
"For the most part, dark matter traces ‘normal’ or baryonic matter pretty well. Dark matter is what formed the gravitational potential wells which allowed for baryonic matter to collapse to form galaxies, stars, planets, etc. This is why we generally expect every galaxy to be embedded in a large dark matter halo."... | [
"I've seen graphics about some galaxies having dark matter being distributed differently from the visible matter. One example is the ",
"https://en.wikipedia.org/wiki/Bullet_Galaxy",
" , I don't remember the other names. Currently I do assume these data to be correct."
] |
[
"Do we actually only have 5 types of taste receptor?"
] | [
false
] | I've been thinking about the frequently mentioned idea that all flavours are made of the 5 basic tastes; salty, sweet, umami, bitter and sour. I can't accept this model the way I understand it. Here's a few reasons why: 1. It implies that every flavour is simply a combination of 5 aspects, and thus you could imitate the flavour of any food using just 5 ingredients 2. There are more identifiable tastes such as metallic, astringent, pungent, cooling, alcoholic, burnt 3. Those flavours come in more than one variety - chilli, ginger and spring onion are all pungent but all have a different pungency. Glucose, sucrose and honey all taste sweet but different. 4. Similar tastes come from chemically distinct molecules - even pure citric acid tastes different to pure acetic acid. How can there be just 5 flavour components if two chemically homologous acids tastes entirely different, despite the lack of any contaminants to add 'bitterness' or 'sweetness' to alter the flavour? Surely every chemical has it's own unique interaction with the taste buds? | [
"Our experience of taste is a combination of the activation of ",
"taste receptors",
" and many other kinds of chemo- and mechanical receptors, such as those responsive to temperature, hot and cool (e.g. menthol), texture, and smell (the general wiki article on ",
"taste",
" covers some of this). ",
"Rece... | [
"First it is important to distinguish between flavor and taste. Taste buds are not the only mechanism at work when perceiving \"flavor\". Typically, when we chew food, the odorant molecules from that food is pushed up into nasal cavity where they stimulate our smell receptors. The combination of the sensations from... | [
"Minor addition: Capsaicin triggers a receptor (",
"TRPV1",
") which is stimulated by both high heat and tearing / abrasion (and also a bunch of other things like acidity). The thermal property is why spicy food tastes hot. TRPV1 is a type of pain receptor (",
"nociceptor",
") and is also found in other par... |
[
"How does an enlarged heart (congestive heart failure) make my dog cough?"
] | [
false
] | [deleted] | [
"Congestive heart failure causes an increase in pulmonary vein blood pressure, essentially due to failure of the heart to pump well. This increase in pressure increases the overall ",
"Starling forces",
" that push fluid out of lung capillaries into the alveoli and interstitial space (lung tissue). This fluid... | [
"Enalipril can cause a dry cough. ",
"Enalipril is an 'ACE-inhibitor' and a dry cough is a common side effect we always warn patients about. ",
"ACE (Angiotensin Converting Enzyme) is involved in regulating fluid/blood volume and is also seen in lungs. ",
"If the dog started coughing after starting the medi... | [
"Medical management can optimize (but usually not cure) congestive heart failure and resultant pulmonary edema; I'm not sure to what extent human therapy is efficacious in animals."
] |
[
"What are the most promising technologies for storing electricity from a solar power plant for cloudy days?"
] | [
false
] | It is currently expensive to store electricity. The idea that I think shows a great deal of promise (with no basis in science) are flywheel batteries...Doesn't matter. My question is about storing power cheaply so that solar may someday be viable. What's going to be the way it gets done and why? Note: this question is not about producing electricity with solar tech but about storing that electricity given a sufficient means to supply it. | [
"Mechanical Engineer here.",
"Pumping water up into a lake for later hydroelectric use is fairly efficient. Solar panels are 15-30% (45% in the lab) and hydroelectric dams can get as much as 90% (depending on how you measure it, it's actually less than that.)",
"That's assuming you actually have water to pump."... | [
"yeah you're right. Wrote that before I had coffee. Not going to change it out of shame :("
] | [
"EDIT: If you want to be possessive, it's EYE TEE apostrophe ESS. If you want to be contractive, it's just EYE TEE ESS. Scallywag!",
"I believe you have backwards.",
". \"Its\" is possessive and \"It's\" is the contraction of \"it is\" or \"it has\"."
] |
[
"Is it possible to collapse a neutron star through impact rather than mass accretion."
] | [
false
] | From what I understand, neutron stars are held up against gravity only by neutron degeneracy. If a large impact (not necessarily by a very massive body) hit a neutron star, the area impacted should momentarily experience increased pressure and compression. Could this trigger a local collapse as the pressure overcomes the neutron degeneracy, leading to a chain reaction that collapses the entire star. Also, if this is true, this should be a fairly common occurrence since most impacts with neutron stars should be very large due to their strong gravitational pull. | [
"Any source of additional pressure will compress a neutron star a non-zero amount. However, unless the neutron star is right up against the ",
"mass limit",
", it will be \"stable\", meaning a small change in pressure will result in a small change in size. Thus a typical neutron star will be quite resilient a... | [
"I'm not a compact object expert so I can't give detailed or rigorous answers about some of these points without spending a lot of time researching it. I suspect that in principle what you are proposing is allowed, but I'm quite confident though that the kind of impact which would be needed is beyond what is likel... | [
"It would seem that such a large explosion should provide enough force to collapse the star if what I suggested is true.",
"It's unlikely that it would be possible to create a large enough explosion on the surface of a neutron star to collapse it just from the force of the explosion. Adding mass is the way to col... |
[
"If you are in water right underneath the moon and the moon is at it's closest, do you float better than other places on earth?"
] | [
false
] | null | [
"Nope! The Moon is pulling both you and the water equally, so it makes no difference to how you float.",
"Tides work because gravity drops off with distance. The near-side of the Earth is pulled by the Moon more than the far side. So the water tends to be pulled away from the middle, and piles up on the near side... | [
"By a negligible amount, yes. Like the difference between inhaling and exhaling."
] | [
"Wait a minute, do you weigh less if you're on the moon side?"
] |
[
"If an object traveling and half the speed of light emmits photons in transit and those photons hit you, did they hit you at 1.5 times the speed of light?"
] | [
false
] | null | [
"See the FAQ"
] | [
"i did, how does this violate them. it's not a homework question, i'm a working adult and have a legit curiosity, if the speed of light is supposed to be the max speed, how can you have light come off something already moving towards you with relative speed of x. wouldn't the photon be going speed of light+x? ",
... | [
"Under the section for physics in the FAQ you can find at least two questions that are the same as this one. "
] |
[
"Are there any animals besides humans which have demonstrated 'thrill seeking' behavior?"
] | [
false
] | Is this behavior unique to us? I've seen some comments about turtles "liking the sensation of falling" but are there any studies that show this type of behavior or is it all speculation? | [
"Lots. Otters sliding down mud banks, wolverines, bears and badgers sliding down snowy hills, birds (especially corvids) suicidally teasing cats, cetaceans breaching, coyotes fucking around with dogs, parrots and other birds working branches like trapeze artists, etc."
] | [
"What's the difference between \"having fun\" and \"thrill-seeking\"? And a crow attacking a cat, or a coyote messing up a farm dog, is always taking a risk of having their day ruined. "
] | [
"Sledding crows:",
"http://youtu.be/mRnI4dhZZxQ"
] |
[
"Is salt a food?"
] | [
false
] | null | [
"Salt is a mineral..."
] | [
"If you take ",
"this",
" definition from dictionary.com, yes."
] | [
"Looking at various definitions of food, the phrases \"maintain life\" or \"sustain life\" seem to be integral. Salt, while certainly useful, does not maintain or sustain our life. You cannot survive on salt and water. I would say that a \"food\" must contain one or more of the major elements C, H, N, O, P, and ... |
[
"How is a galaxy formed?"
] | [
false
] | null | [
"There's a lot of research currently being done by astronomers and astrophysicists on more accurately answering that question. It's thought that when a galaxy first forms it takes a disk shape (which can later change), and theories about their formation tend to fall under the categories of either 'top-down' or 'bot... | [
"How does dark matter clump together? I was under the impression that the only way for it to dissipate energy was through gravitational waves and that seems quite slow?"
] | [
"There's a lot of research currently being done by astronomers and astrophysicists on more accurately answering that question. It's thought that when a galaxy first forms it takes a disk shape (which can later change), and theories about their formation tend to fall under the categories of either 'top-down' or 'bot... |
[
"Why do bacteria not get crushed and die when objects millions if times their mass are placed on them?"
] | [
false
] | Bacteria are so tiny that even the lightest of objects would be extremely heavy in comparison. How is it that they are able to survive under the weight of things when they are so extremely small? | [
"This is a problem of perspective. ",
"Is that super heavy item perfectly smooth on a cellular scale? Is the object the bacteria is on also perfectly smooth? \nThink of it like steeping on a small bug, if the grooves in your shoe happen to land on the bug, it will appear to have survived the stomping. When in fac... | [
"Along the same lines, even if the object were totally smooth along with a smooth mat of bacteria you shouldn't think of all the force applied to one bacteria. You need to look at the pressure applied to a single bacteria. Since the area of that bacteria is so small, it's a really small force on any one bacteria. I... | [
"Why don't your own cells get crushed by your body?",
"It's because the forces are tiny on tiny scales. 100 kg weighing down on, say, 100 cm",
" (part of a foot) can create a lot of pressure (nearly 100 kilopascals), but on the scale of a tiny cell, which may be only 100 microns x 100 microns in cross section f... |
[
"Can a star cool down enough and become a giant planet?"
] | [
false
] | null | [
"When stars cool down(fusion in the core slows down), gravitational forces overcome outward heat pressures causing the star to shrink, this compression in turn causes the temperature to increase again until the star is hot enough to fuse heavier elements. ",
"For large stars the final shrink results in a supernov... | [
"Brown dwarfs are just failed stars. Basically the temperature didn’t get hot enough at the beginning for nuclear fusion to begin so they’re just big balls of dust and gas."
] | [
"So we only have to wait about 10,000,000,000,000,000 years (a bit less than a million times the current age of the universe) for a white dwarf to cool to a nice, reasonable 300 K so we can land and start mining for diamonds.",
"Of course, the surface gravity of that black dwarf will be about 300,000 G, but I'm s... |
[
"I assume most “cavemen” didn't actually live in caves. Where, then?"
] | [
false
] | I have an image in my mind of Neanderthals living communally in a cave. But I'm sure that's not really the case. What was their typical domestic situation? | [
"I don't think anyone knows for certain. Virtually all of their sites predate the last ice age and were in europe, so most were probably hopelessly destroyed or buried by glaciers. The cavemen thing arose because most of the earliest neanderthal remains we found were in caves. That probably has more to do with t... | [
"OK, several things to address here. Firstly, you have to realize that Paleolithic archaeology has an inherent bias in it towards Europe, especially the Perigord in France, simply because it's where the people who first started asking these questions lived, and that terrain is dominated by caves and rock shelters.... | [
"How about you just explain the part that he didn't catch, instead of being a dick."
] |
[
"What causes the onset of puberty specifically?"
] | [
false
] | null | [
"GNRH release is regulated by KNDY-neurons (Kisspeptide-neurokinine B -dynorphine)",
"The KDNY neurons get stimulated by progesteron, we get release of Kisspeptide which stimulates the GNRH neuron and releases GNRH",
"GnRH then binds on the gonadotropic cells which causes the release of FSH and LHLH and FSH sti... | [
"If I've learned to extrapolate anything from BioChem, there's probably a gonadotropin releasing hormone releasing hormone.",
"And also a gonadotropin releasing hormone releasing hormone releasing hormone.",
"It's releasing hormones all the way down."
] | [
"Makes sense from evolutionary point of view. Oh there is enough food? Then we can go into this major growth, that requires a lot of energy. Oh there is not enough food? Let’s wait another year or two and hope that the situation is better then."
] |
[
"Can non-planetary celestial objects have ring systems?"
] | [
false
] | Would it be possible for a star, moon or black hole, for example, to have a ring system as prominent as the ones that planets can have? If so, how would the characteristics of these ring systems differ from the ones of planets? | [
"It was previously thought a fairly massive body was required to maintain a ring system, but the recent discovery of ",
"rings around asteroid 10199 Chariklo",
" disproved that idea. That said, they're nowhere near as massive as the rings found around the giant planets."
] | [
"A black hole will develop an accretion disk if matter is falling towards it. But it's very different from a ring like Saturn's. The matter in the disk is shedding a heck of a lot of gravitational potential energy, so it gets extremely hot and radiates a lot of energy. Some of the brightest objects in the universe ... | [
"One example of a non planetary ring system is when you have 2 companion stars in a binary system, and one partner is at the end of its stellar evolution (e.g. white dwarf or a more exotic compact stellar object). It can pull mass from its companion. The mass coming from the companion can form an accretion disk aro... |
[
"Has the belief in homeopathy decreased within the past few years?"
] | [
false
] | It seems like I very rarely hear about homeopathic medicine treated as anything other than quackery anymore. A few years ago it seemed like the Next Big Thing in alternative medicine. What has caused this, or am I incorrect and it is still widely believed in? Disclaimer: I know homeopathy is objectively BS, just curious where belief in it is compared to 5-10 years ago. | [
"Chiropractic has only been shown to help with certain forms of lower back pain, and even then at relatively low significance. If chiropractic is helping people it's coincidence, as it is not an evidence-based practice.",
"Some chiropractors are also physical therapists or otherwise incorporate non-chiropractic m... | [
"Chiropractic has only been shown to help with certain forms of lower back pain, and even then at relatively low significance. If chiropractic is helping people it's coincidence, as it is not an evidence-based practice.",
"Some chiropractors are also physical therapists or otherwise incorporate non-chiropractic m... | [
"Herbal supplements in general are very different than homeopathy specifically, many have plenty of research to back them up."
] |
[
"CRT minus the vacuum?"
] | [
false
] | So, what would happen if a crt's beam was outside of vacuum, say you removed the phosphor wall from a monitor, or just removed the vacuum all together, would it operate, or would it just ionize the air all around it? | [
"The latter. CRT's emit beta rays, which, like you said, would ionize the air."
] | [
"They're the same thing."
] | [
"Do you mean beta particle, or are beta rays something different?"
] |
[
"When blind people \"see\" for the first time, do they see everything upside down?"
] | [
false
] | [deleted] | [
"Although it is true that the image on your retina is inverted (up-down and left-right), it is only inverted to an outside observer. That is, if I am looking at your eyeball, the bottom part is getting light from the upper part of the world (relative to my being upright). ",
"But your brain is not an observer. It... | [
"People have done similar experiments to what you're talking about using prism googles. The prism bends the light in such a way that it makes everything look upside down. If you wear prism goggles like this for a long time, you will eventually get used to seeing the world upside down. You'll learn to account for th... | [
"That's very similar to the ",
"Backwards Brain Bicycle"
] |
[
"Why is n-heptane such a commonly used fuel for fire in experimints?"
] | [
false
] | I have read many articles about experiments with fire, and they often use n-heptane. However, they never explain why they use this specific substance, and I couldn't find it via google. | [
"I would put my money on that it is a liquid that is cheaply available and burns quite nicely. "
] | [
"This is correct. Additionally, it doesn't have a particularly low boiling point like pentanes (36 °C) and is significantly less toxic than hexanes (a neurotoxin). Pharmaceutical companies often use heptane over hexane for this reason, although academia generally does not as heptane is more expensive."
] | [
"And it's a single compound so you can be sure it's the same every time, not like hexanes which is widley used as solvent, but can have slightly different properties depending on the composition."
] |
[
"What causes you to lose your voice?"
] | [
false
] | If your vocal cords are just muscles that force air to pass through it, then shouldn't it be more difficult to lose your voice from just yelling all night? | [
"They aren't muscles, really. They are more like soft mucous membranes that vibrate when air passes over them, rather that vibrating from direct muscle activation. ",
"Losing your voice has less to do with \"wearing the muscles out\" as it does damaging and inflaming the membranes, causing inefficient vibrations.... | [
"How does vocal training to reach pitches that you normally couldn't hit work?"
] | [
"That's outside of my field of specialty. I'll defer to someone else before I speculate."
] |
[
"How do volcanologists determine that a volcano became dormant millions of years ago?"
] | [
false
] | How are they able to get estimates like that? How is it possible to tell that a volcano last erupted millions of years ago? | [
"In reality within volcanology we only ever talk about active and extinct - dormant is pretty meaningless. Even active and extinct are only ever really used colloquially.",
"The term extinct tends only to apply to systems that we believe have no active magma plumbing system. Now, we can look at local sediments to... | [
"Wow, thanks for the explanation! That's really interesting!"
] | [
"How did you end up in volcanology and sedimentology? All volcanologists and sedimentologists I know can't stand eachother."
] |
[
"Did people have photosensitive epileptic seizures before TV's were invented?"
] | [
false
] | I've tried looking up info about it on Google but I wasn't able to find the answer to this question. Basically, would people have had flashing-light-based seizures before the technology to produce it was invented? | [
"ever tried to run next to a fence made out of vertical slats while the sun is shining through it? Same with trees essentially."
] | [
"ever tried to run next to a fence made out of vertical slats while the sun is shining through it? Same with trees essentially."
] | [
"Not an expert, but I do have epilepsy, though it is not the photosensitive kind. I doubt that the commonness of a stimulus correlates to sensitivity to that stimulus in epilepsy patients. In other words I think yes, people had photosensitive epilepsy before flashing lights were common. But I could be wrong; sensit... |
[
"What’s the difference between the 2009 Swine Flu pandemic and COVID-19, and why weren’t masks/lockdowns encouraged in 2009?"
] | [
false
] | [deleted] | [
"The H1N1pdm09 influenza virus is less than half as transmissible as SARS-CoV-2 (R0 around 1.4 vs 3-4 for SCV2), and has less than 1/100 the mortality rate (0.001-0.01% vs 0.5-1%) (",
"CDC: 2009 H1N1 Pandemic (H1N1pdm09 virus)",
"), with a similarly lower rate of long-term complications. Of course there was les... | [
"Masks were widely used in many countries, though not so much in the US",
"It's worth noting that ",
" of masks was not high in the US. But the fact that our national PPE stockpile was depleted after 2009 is pretty good evidence that healthcare workers did use masks pretty extensively in the 2009 H1N1 pandemic... | [
"The first paper makes a modelling assumption that I found the be ultra-wrong where I live. That masks are used \"always\". In october in Italy they mandated to have masks always on where you were outside your home. So you had to wear one while walking on the road, where the attack rate is like 10",
" And survey... |
[
"What non-combustive means of propulsion are feasible for leaving earth orbit?"
] | [
false
] | Many are familiar with the more popular speculations concerning interstellar space travel: Ramjets, Solar Sails, Nuclear Bomb propulsion, etc.. What I'm asking is if there are proposals for leaving earth (other other bodies) orbits other than modern solid fuels like ammonium perchlorate and the like. | [
"Would these photons be able to overcome earths gravity and propel a craft out of our atmosphere? "
] | [
"Would these photons be able to overcome earths gravity and propel a craft out of our atmosphere? "
] | [
"The only issue I see arising from that method is earth's escape velocity.",
"The needed 11.2 Km/s would have to be achieved in a fraction of a second in a rail gun. The g-force upon contacting earth's atmosphere would crush any human and likely damage most cargo.",
"On the moon it might work, but I can't see i... |
[
"(chem/phys) What kind of bond is created when I heat eggs in a frying pan and they \"stick\" to it's surface after? For the food that is really \"stuck on\", has this food diffused into the surface of the pan, or is their no atomic mixing at all? If not, then what accounts for the actual \"stickiness\"?"
] | [
false
] | null | [
"Usually when cleaning pans at the restaurant, we use sodium hydroxide mixed with water (it doesn't say on the label, but that's pretty much what it is). The highly basic or caustic solution pulls the burnt carbon off the cationic metal, and this reaction speeds up under heat. ",
"Along with this, if something ... | [
"The reaction between Sodium Hydroxide, and the Metal under heat, is proof that a bond is present. ",
"The metal essentially acts as a Cation for the Anionic Carbon. It however is not soluble in water, the Carbon essentially prefers Na to the Metal. "
] | [
"Most importantly: If your eggs are sticking to your pan then you are over heating your pan when you cook your eggs.",
"They should stick initially (during which time you shouldn't move them) but then once they are cooked they should come off the pan easily. If they stick at the end then you're burning them.",
... |
[
"How are calories in food determined?"
] | [
false
] | null | [
"In the 19th and early 20th centuries they would burn food to determine how many calories it contained. This worked by placing the food in a “bomb calorimeter” filled with water at a measured temperature, and then burning the food via an electrical current that would be applied. Directly after the food was comple... | [
"I don't know how it is measured today, but calories can be determined (not with the most validity) by burning the substance in a calorimeter with water, and based on the specific heat capacity of water ( 4187 joules / litre degree celcius) and the amount of degrees the water increased it can be calulated what the ... | [
"I don't see how the practice would be found impractical by the need to list nutritional information. It is still required to state the energy in the product, and that can't necessarily be done by measuring the energy content of a product's constituent ingredients.",
"What replaced the bomb calorimeter?"
] |
[
"How do we measure the height of mountains on planets with no sea level?"
] | [
false
] | Olympus Mons was recently compared to Mount Everest and I was wondering how comparable the survey methods were. | [
"I too saw this Reddit link. The Wikipedia page talks about this a bit; ",
"https://en.wikipedia.org/wiki/Olympus_Mons",
". This leads to a discussion of the Mars global datum, defined as (from ",
"https://en.wikipedia.org/wiki/Geography_of_Mars):",
"On Earth, the zero elevation datum is based on sea level.... | [
"So let's start on Earth. Sea level isn't really defined as the elevation of the ocean surface. The ocean's surface is variable due to how much water is coming in vs. going out, tides, weather, and other factors. Sea level is actually defined on Earth based on gravity measurements. Earth's gravity has been mapped f... | [
"First you need to define a zero altitude. Height is a relative value instead of an absolute value.",
"If the planet has atomsphere, we can use the pressure deference between the mountain top and the defined zero altitude to find out the height of the mountain. You will also need to measure Temperature lapse rate... |
[
"When a photon reflects off of a mirror and changes direction, does it decelerate, stop, then accelerate like objects with mass do?"
] | [
false
] | null | [
"Choose and want are not right words here. Photons can't choose or want something. It just happens randomly. Also particle never splits off. It is just a probability wave until it is observed. This wave collapses when it's observed. "
] | [
"I never understood how this can be the scientific explanation.",
"To really understand it you need a lot of math, I fear."
] | [
"Photons never stop in the sense you're speaking of, so no. A precise view of what happens is rather difficult since we're dealing with a quantum particle; in a sense it interacts with the mirror and takes all possible paths settling on one upon measurement (all the paths add to the quantum amplitude). Some photons... |
[
"How do people recover from the Wuhan coronavirus?"
] | [
false
] | I was told that there is currently no cure for the Wuhan coronavirus and the death rate is 10%, so how are the other 90% surviving/recovering | [
"The same as how you recover from other viruses like the common cold, your body naturally fights it off using ",
"antibodies",
" and other parts of the ",
"immune system",
".",
"Cornaviruses cause respiratory problems such as pneumonia, an inflammatory condition of the lungs. Most people can survive these... | [
"The human body is pretty good at fighting off viruses if a person has an intact immune system. Generally speaking, viruses are less robust than other pathogens like mycobacteria or bacteria in a spore form. Think about getting over a viral cold vs getting over tuberculosis (mycobacterium). ",
"Both your innate i... | [
"I'm conflicted on this because on one hand China has done that in the recent past and there are reports of hospitals in Wuhan not even taking peoples temperature before turning them away. On the other hand, the response is ",
" more robust than we've seen in the past and deserves recognition."
] |
[
"Why do most people who experience psychedelics come to a conclusion of wholeness and one with the universe?"
] | [
false
] | I'm an atheist, rational thought prevents me from believing in any sort of deity, however every psychedelic experience I've had so far makes me question such things since the experience is almost every time of strong spiritualism. I've tried reading journal articles about psychotropic effects on the brain, alas, I do not understand it. Anyone has an explanation for this in layman terms? Thank you. | [
"Hey people, I realize this question provokes a lot of questions about existence, reflection about life, and anecdotes about experiences you've had with drugs, but this is AskScience. We're looking for scientific answers that cite published works. Thanks!"
] | [
"I'll split my answer up into a few bits to make it a bit clearer and I'll come back and add to it if I have some more time today.",
"It's a common side-effect of psychoactive drugs. There was a seminal study - Pahnke (1966)- explanation of this study taken from a ",
"follow up paper",
":",
"In a Boston cha... | [
"Here's a ",
"video",
" of a neuroscientist explaining this very phenomenon, but it was induced by temporal lobe epilepsy rather than using drugs, but I think the explanation is valid for both."
] |
[
"How is blood tested for dopamine, serotonin, and/or norepinephrine? How are 'levels' determined; e.g. what is the actual mechanism of the test?"
] | [
false
] | I've been learning about different theories of human emotion and many of them focus on the three molecules listed in my title question. This lead me to wonder how these molecules are tested for. Since biology is one of my weaker areas of knowledge, I tried looking around on the web for how these substances are extracted and/or tested for; however, I found little information. Most of what I found focused on lay peoples' personal medical experiences–off topic for me. And, since I don't know what these tests are called in their professional context, I can't get my search on. What I'm curious about is how, in general, these substances are detected in the blood and how, from a technical perspective, the concentrations are determined. I was hoping that a basic description would lead me to a basic understanding the correct terminology so that I could study further on my own. Thanks. edit: Everyone, thanks for so many responses. It will take me a while to read through all of them but you all have given me a great start to my journey. Cheers! | [
"Not at all my area of expertise, but I found at least one potentially useful article that explains this stuff on a molecular level!",
"Serotonin Detection Method",
" \nJust looking at the abstract, it looks like the researchers used this \"hyperbranched viologen polymer\" as sort of a marker for the presence o... | [
"Many have mentioned antibody based strategies although I do not think they are standard for these specific molecules. These types of assays can take many forms (lateral flow, ELISA, suspension bead array). The way they typically work is you have a labeled antibody (your signal) that binds to the small molecule. Th... | [
"Or you can use a monoclonal antibody for serotonin. That would work for an ELISA or western blot if you're working with blood samples"
] |
[
"How could a body decompose in a sterilized room completely clean with no bacteria to break down the flesh?"
] | [
false
] | I know we have bacteria all over us already but what if they body was cleaned? | [
"To add to the other commenter, [[edit: well now this is on top, so my comment is about ",
" to internal microbes leaving you with a only skeleton]] there are definitely different levels of decomposition that can happen. You won't always be left with a skeleton. Sometimes you may be left with a \"natural mummy\" ... | [
"To add on to this, the Tarim basin in northwest China has produced large numbers of ",
"extremely well preserved mummies",
" due to the area having a perfect combination of saline soils, incredibly dry summers and freezing winters, with the bodies often buried in tombs or exposed coffins. Politically, the mumm... | [
"Depends on the type of 'sterile' environment you're in. Depending on temperature, there are several ways for a body to decompose. Normally, your mucous glands all along your intestines keep your digestive bacteria in check, so once you dies, and those mucous glands stop protecting your gut, those bacteria start di... |
[
"Is it possible to transfer one’s organs into another body and become that person?"
] | [
false
] | null | [
"Personality, memories, etc. are stored in the brain, not the organs. At present, it is not possible to do a brain transplant."
] | [
"So if a brain transplant is possible, then the transfer of memories and stuff is theoretically possible? "
] | [
"In theory -- because that's where memories are stored. "
] |
[
"How do birds keep from running into each other when in large groups? Especially amazing to watch them take off simultaneously."
] | [
false
] | I have a bit of a hobby building small robots (using micro controllers and any available scrap electronics and so on) and my next project is going to be an attempt at a hive-mind thinking among multiple micro controllers. Just going about my day I noticed that even a large flock of birds when taking off simultaneously maintain an almost equal distance from each-other and mange to never interfere. Has anyone studied similar behavior and logic among birds or other animals or read any interesting articles or studies? Edit: Found some articles on blind fish and their organs, however i'm more interested in how they coordinate so well, not the organs they use, seeing how i'd like to implement it in my little robot swarm. Link: | [
"I don't know if this is how birds avoid collision, but schooling fish have an extra sense (I think it's called a horizontal line, but don't quote me) that even blind fish can swim in formation"
] | [
"I'm not a biologist so take what I'm saying with the appropriate amount of salt.",
"Flocking behavior has been simulated since at least the 80's with Craig Reynolds' Boids algorithm. With a few simple rules like neighbor avoidance and alignment with local neighbor's directions, you can create very lifelike-looki... | [
"I was listening to Richard Dawkins talk about this just the other day (in ",
"this podcast",
"). He referred specifically to 'local rules' as you mention. Although a maneuvering flock has the appearance of a hive mind, he says it is simply the result of each bird following the same set of rules, following or r... |
[
"How are modern transistors manufactured?"
] | [
false
] | With the current generation of GPU's and CPU's being released and talked about I keep seeing terms like 14nm and 7nm being thrown around. I sort of took this as an arbitrary number for a while and didn't think about it. However when I started doing some research, I realized that 14nm's is only ~7 silicon atoms wide. With that in mind, the NVIDIA 3080 is advertised as having 10's of billions of transistors. How is it possible to manufacture these on such scale to supply demand, and without error so that the chips actually work. | [
"Mostly due to advances in photolithography machines (e.g. ASML). The wavelength of the lasers used for patterning are being pushed lower, as this is one way to improve the resolution of printing the patterns to build up transistors and microchips. The latest machines are using 13nm Extreme Ultraviolet light. It is... | [
"Also in case it wasn't obvious to the asker: They don't make 10 billion little transistors and then put them on the chip. They make them all at once in different patterns, directly on the chip."
] | [
"Mostly due to advances in photolithography machines (e.g. ASML)",
"Just to clarify: ASML is a leading manufacturer of photolithography machines."
] |
[
"Rupert Sheldrake - The Science Delusion @ TEDxWhitechapel | would love to see the community respond to/debunk/discuss some of these claims."
] | [
false
] | null | [
"At 4m 29s he talks about \"Dogma 9\"",
" about telepathic phenomena being impossible.",
"He seems to misunderstand the ",
"word dogma",
" ie an \"official system of belief or beliefs\". Science doesn't deal in beliefs and certainties, only in evidence and models and theories and probabilities.",
"Further... | [
"This is the relevant TEDx video",
". He ",
"describes himself",
" as \"best known for his theory of morphic fields and morphic resonance, which leads to a vision of a living, developing universe with its own inherent memory.\" ",
"I have only just started watching his video, but I note he ",
"believes in... | [
"At 5m 10s he talks about Dogma 10",
" - a distinction between what he calls \"mechanistic medicine\" which scientists 'believe in' on the one hand and \"complementary and alternative medicine\" on the other.",
"I have not heard the term \"mechanistic medicine\" before, and do not think the term is widely used.... |
[
"Can we make sounds visible?"
] | [
false
] | Can we now or in the future film in such high definition that we could see materials vibrating due to sounds? For instance the wood of a table reverberating the sounds coming from headphones lying on top of it? I don't remember what movie it was but this supercomputer went rogue and trapped the characters inside a facility. The computer could hear their plans to escape through microphones. When they found this out, the disabled / destroyed the microphones. To be able to "hear" what they were planning, the computer reconstructed their voices through analyzing the vibrations in a cup of water. The closest example I can think of is . | [
"Yeah, it's pretty easy and we acousticians do it all the time for many reasons. There are a couple ways that we make sounds visible or use light to sense sound.",
"The first thing that comes to mind is high-speed video, like the one you showed of the drum. But we can actually do something similar that's visible ... | [
"Sorry for taking so long to reply, I wanted to find exactly the right video to show things off.",
"As for your first question, in the average living room, the vibrational modes of objects don't really matter. For the most part, sound either bounces off of objects or gets absorbed by them, so the most importance ... | [
"This is seriously fascinating! Thank you for your answers. Now for the follow-up questions :-). ",
"We can see the mode shapes on the drum head, and vibrations of the tuning-fork in one of your videos. But how do objects, say in an average living room, vibrate and how does this influence the sound? Could it be t... |
[
"If light in a vacuum travels a Planck Distance every Planck Time, doesn't that mean that all slower objects would move less than a Planck Distance for every Planck time?"
] | [
false
] | null | [
"The idea of \"the universe is divided into Planck length pixels that update every Planck time\" simply isn't an aspect of modern physics. It's just a semi-common misconception."
] | [
"They are useful because they are constructed from physical constants and not anything referenced to Earth or humans, like the SI units are. They also roughly set the scale of quantum gravity. See here: ",
"https://www.physicsforums.com/insights/hand-wavy-discussion-planck-length/"
] | [
"So time and distance are ",
" quantized? ",
"If so, what's the meaning of the Planck Units? "
] |
[
"Do liquids float on themselves?"
] | [
false
] | What determines why a certain molecule of water, for example, is held above others? From my rudimentary physics knowledge, a free-body diagram of an individual molecule at the top of the container would include gravity, the force of the liquid wanting to spread out (don't know the technical term), the force of the container pushing back (creating equilibrium), and some force pushing up. What is that upward force? | [
"The upward force is the normal force of the molecule under it (just like how you're not falling through your chair because your chair provides a normal force that equalizes with gravity). However, water molecules are constantly moving if in a liquid.",
"Keep in mind that if you have a glass of pure water, the wa... | [
"That's awesome! I suppose it makes sense that it would just be the molecule underneath it. Thank you very much, I really appreciate it!"
] | [
"One more quick question: Is the density of a liquid therefore dependent on the size of the molecules themselves?"
] |
[
"Can anyone tell me why this small boulder looks like this?"
] | [
false
] | Found it along an old stone wall in the woods. It doesn't really look like the other rocks in the area. Has a nice wavy thing going on. | [
"Well, it is difficult to tell exactly from the pictures, but there would be a definite test you could do to tell exactly what it is. If you have access to some HCl or even a strong vinegar, you can drop some on a surface that you break off. If it fizzes, then it is most likely an algae mat or some biological organ... | [
"For that to be true, you'd need to have the whole rock unit folded, which is clearly isn't. "
] | [
"the boulder is not in place. it's part of stone wall."
] |
[
"Titan squeezes and stretches as it goes along its elliptical orbit around Saturn, causing heating in its core. Is this unlimited energy, or if not, where does this energy come from?"
] | [
false
] | null | [
"Over time, it will break up and dissolve into a cloud of dust.",
"I would have thought that the orbit would simply decay, as that's the source of the tidal energy."
] | [
"Physics bachelor here.",
"The answer to the question \"Is this unlimited energy\" is always no. Sometimes something looks unlimited, but that's just because we are small and live short.",
"The energy generated on Titan can be classified as \"tidal energy\". We have something like that on earth too, the tides o... | [
"In the specific case of titan, the squeezing and stretching deteriorates its structural integrity. Over time, it will break up and dissolve into a cloud of dust.",
"At the scale of a planet or large moon, all materials function as liquids. There is no large scale \"structural integrity\" to deteriorate.",
"The... |
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