title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Compared the moons of other planets in our solar system how special and unique is our moon? Is there something our moon has that is unique to it?"
] | [
false
] | Hi! I was reading that planets like Jupiter, Saturn, Neptune and Uranus have dozens of moons and I immediately thought about our moon Compared to the moons of the other planets in the solar system how unique is our moon? Does our moon has something that is unique to it? Or is our moon one of the most boring and most du... | [
"The fact that it has approximately the same angular size in our sky as the sun is pretty amazing and special.",
"https://astronomy.com/magazine/ask-astro/2000/10/why-is-the-moon-exactly-the-same-apparent-size-from-earth-as-the-sun-surely-this-cannot-be-just-coincidence-the-odds-against-such-a-perfect-match-are-e... | [
"Our moon seems to have formed in a particular way that seems different from most of the others. Most moons appear to have accreted out of a planetary disc at the same time the planet formed, or were captured by the planet later.",
"The Earth Moon system, on the other hand, formed later, when a theoretical plane... | [
"Although technically not a planet, Pluto also has an unusually large moon for its size, Charon. Although it's still not settled science, one of the leading hypotheses for the formation of Charon is a giant impact, similar to the one that formed our Moon."
] |
[
"What difference in alkaloidal content is there between drip coffee and espresso besides caffeine?"
] | [
false
] | Obviously there is a higher amount of caffeine per fluid ounce of coffee in espresso, but considering the intensity of the extraction process in espresso, the amount of essential oils lost in a paper filter, and the amount of other active compounds in coffee, I'm wondering what differences would occur with the rest of ... | [
"You would be able to expect the same extraction efficiency for similar compounds. ",
"I dug around a little and was looking for literature that discussed this well, considering that other alkaloids are bioactive compounds there was really limited literature, and even less that I would be confident in citing. ",... | [
"This is almost certainly true. The milk will make the absorption time take much longer in a diluted espresso drink than straight coffee. Also the amount of milk that goes into most espresso drinks is much higher than the amount of milk most people put into drip coffee. I don't know if you've ever tried straight... | [
"Can I take this a step further? I have frequent hearburn and take medication for it but I've noticed that drip coffee will hit me quicker and harder than Espresso coffees. Is this just due to the fact that when I get an Espresso its usually in Latte/Cappuccino which typically is going to have more milk content th... |
[
"Metallurgy: When melting metals to produce parts or beams for things, what stops the metal pot/cauldron from getting to melting point and just combining with the melted?"
] | [
false
] | If it is just a metal with a higher melting point, then what about when you want to melt that and make parts out of that? | [
"Not a materials scientist, but...",
"Answer:\nUsually you would use a metal with a higher melting point, or to cast those metals you would use something like graphite or a ceramic.",
"Exposition:\nCeramics actually have really low thermal conductivity, which is why they make fantastic heat shielding on spacecr... | [
"This is correct. For most typical metals, ",
"refractory ceramics",
" can stand up to direct exposure to the molten metal, even after reaching thermal equilibrium. ",
"For ",
" high-temperature materials, one trick you can pull is using a heavily water-cooled copper crucible. Some of the material you're tr... | [
"the laddles are made of refractory brick or castable refractory that has a higher melting point than the metal. You usually would not want to melt steel or another metal in a higher melting point metal container at a large scale because the heat loss would be way too high. Refractory bricks have better insulating ... |
[
"Is time dilation at very high speeds an effect of entropy happening at a slower rate?"
] | [
false
] | null | [
"No. Time dilation arises becauses observers in a relative state of motion will find themselves measuring space and time differently (in just the right way so that they'll both see any given light beam traveling at speed ",
"). Time dilation will occur in non-thermodynamic systems where there is no issue of entr... | [
"No, this is an effect of the nature of ",
"spacetime",
". It is not related to changes in entropy at all."
] | [
"Great answer, having a hard ",
" wrapping my head around this. Follow up question, is the \"arrow of time\" related to entropy?"
] |
[
"Determining length of a year"
] | [
false
] | How long would it take to determine the length of an Earth year from scratch? Say you had access to telescopes and clocks, and had basic knowledge of how the Earth revolves around the sun, but didn't know the size/shape/duration of the orbit. Would it take multiple orbits to get an accurate measurement? Could you tell ... | [
"Say you had access to telescopes and clocks, and had basic knowledge of how the Earth revolves around the sun, but didn't know the size/shape/duration of the orbit.\nWould it take multiple orbits to get an accurate measurement? Could you tell after, say, 1/4 of a year that you'd completed 1/4 of the orbit?",
"Ho... | [
"Doesn't this assume that the orbit is a perfect circle, rather than elliptical?"
] | [
"changed the calendar to not have leap years on years that are divisible by 100",
"Almost -- no leap year in a year divisible by 100 ",
" the year is divisible by 400, in which case it ",
" a leap year. (The year 2000 was a leap year for this reason.)"
] |
[
"Would a sterling engine be able to power a satellite in earth orbit?"
] | [
false
] | [deleted] | [
"Photovoltaic panels are already incredibly efficient in space applications. It's likely that the extra size and weight of the collector, stirling engine, generator, and the large radiator necessary would remove any advantage in terms of watts/kg, even if you could improve on the watts/sq. meter figures, which is a... | [
"Stirling"
] | [
"sorry, watching too much madmen ",
":D"
] |
[
"How can it be objectively determined that the faces seen in dreams are all faces seen previously throughout the course of one's life?"
] | [
false
] | I've seen some little factoids that I'm a bit wary of stating that scientists discovered that the faces a person sees in dreams are never a completely unique face. Instead the brain projects faces from passersby and images in the background (TV, photographs, etc). How true is this chain-mail trivia-esque "fact," and ho... | [
"This sounds like a mall trivia distortion, a bit like the idea we don't use 90% of our brains. Certainly, everything your brain knows about faces it observed at some point, so it seems safe to say that faces in your dreams are composed out of these memories!",
"But to say that nobody anywhere, ever, has seen a ... | [
"Why not phrase the question \"how could such a finding be objectively falsified\"?",
"It's clearly false when you consider monster faces in nightmares.",
"But still seems hard to \"objectively\" and \"scientifically\" \"prove\"."
] | [
"Exactly! I saw that and immediately wondered how anyone could state with a high level of confidence that dream faces were piecemeal replications of existing faces from a person's periphery. I know there's that prototype brain monitor lets scientists partially reconstruct visual stimuli, but certainly not at the le... |
[
"How will quarantine affect our immune systems, not being exposed to day to day germs now?"
] | [
false
] | Since we are in quarantine, for the most part we don’t leave our houses now. And when we do, we are preventing contact with germs with face masks and washing our hands. Given this, I’d assume our immune systems are getting much less practice now. Does that mean they are getting weaker the longer we quarantine? | [
"For the most part, there is no prevention of contact with germs. Everything in your house is covered in viral particles and bacteria. Everything outside as well. Viruses/bacteria/other microorganisms are always around us and on us, dying, reproducing, and getting exchanged with the environment.",
"What the quara... | [
"Your immune system absolutely does know the difference between harmful and non harmful. That’s how it works. ",
"The initial triggers of an immune response are because cellular ",
"PAMPs",
" (pathogen-associated molecular patterns) trigger ",
"PRRs",
" (pattern-recognition receptors) that lead to the who... | [
"There are 2 types of immunity. The Innate system, and the Adaptive system. And the first line before that",
"The first line is a physical barrier. Your skin, your nose hairs and mucus, and your stomach acid are all extremely effective barriers that keep the vast majority of micro-organisms from ever even reachin... |
[
"When a vaccine is 70% effective, what does that mean - are 70% of recipients protected 100% or are 100% protected 70%?"
] | [
false
] | Hopefully the title summarises it well, however incase it isn't - say in COVID-19 the AZ vaccine is 70% effective, what does that actually mean though: Are 70% of people protected against 100% of exposures - and 30% get no protection, or Do 100% of people have their risk of contracting the virus at each exposure by 70%... | [
"Population wise, your two scenarios have the exact same consequences. In a large group of people, there is no difference between everyone having a 30% change of getting infected and 30 of them having a high chance of getting infected. ",
"That being said, no, it means 70% of the people will be covered, and 30% w... | [
"I guess my question related to potential exposures being included in this.",
"Let's say we had 100 people who each had 1 exposure to a virus - if 30% are vunerable or there is a 30% reduction in chance from an exposure - the numbers are identical; 30 of 70 are infected.",
"Where I guess I see it making a diffe... | [
"The percentage is from the trials is the difference between those that got the placebo and those that got the vaccine and eventually ended up getting the virus. ",
"So let’s say you were following 100 people. Step one, make sure no one has the virus. Then give 50 of them the vaccine and 50 the placebo. It’s doub... |
[
"What is happening when you're sick and you can no longer taste anything?"
] | [
false
] | null | [
"Most of the sense of \"taste\" is actually the sense of smell. Odorant molecules waft up the back of your throat into the nasal cavity. The brain automatically interprets these odors as coming from your mouth, but your nose is actually where the detection is happening. So, any time you have a stuffy nose so that t... | [
"Very interesting. What purpose do taste buds hold then? If I didn't have a tongue could I still taste?"
] | [
"The vast majority of taste/odorant molecules - over 400 types - are detected in the nose - but there are 5 tastes that are indeed detected by the tongue: salty, sweet, bitter, sour, umami (\"savory\", or more specifically, single amino acids, meaning, the taste of cooked protein). These seem to be the components o... |
[
"Is there a model for calculating when matter changes state?"
] | [
false
] | So we know for example that water goes from liquid to gas at 100°C But what are the dimensions that decides this? Is there a way to determine at what temperature and pressure some specific matter changes state? Or do we simply know these things because of empirical evidence? | [
"You can use very heavy computational techniques such as density functional theory to predict things like phase transitions, but this is actually very difficult, particularly for strongly interacting liquids like water. ",
"DFT is pretty bad for phase change simulations for a lot of systems because phase changes ... | [
"On a side note I was browsing through the document and saw this line.",
"This is not a formal issue with Monte Carlo, as in the infinite time limit where Monte Carlo is formally defined, eventually the system will leave any configuration, and ergodicity ensures that the proper ensemble average will be obtained. ... | [
"It is difficult to calculate liquids. One needs to do molecular dynamics simulations with lots of approximations for a large number of molecules, or quantum Monte-Carlo. Water is especially difficult, with hydrogen bonding and quantum behavior of the protons."
] |
[
"If photons have no mass, why does a black hole trap them?"
] | [
false
] | Do black holes not only have huge gravitational pulls but also energy pulls? Please explain. | [
"A photon does not require mass to be affected by gravity as the source of gravity is not mass, it is energy and momentum, which a photon definitely has. MinutePhysics has a great ",
"video",
" explaining this and some other common physics misconceptions."
] | [
"I don't really like the E = Γ m_0 c",
" explanation, since it rather suggests the idea of relativistic mass m = Γ m_0, which doesn't really reflect what's happening. ",
"I think expressing energy in the form E",
" = m",
" c",
" + p",
" c",
" is more illustrative, as it shows that energy is explicitly... | [
"The mass of the black hole warps space-time so much that, inside the event horizon, all paths into the future lead back towards the center of the black hole. The photon cannot escape because it travels in space-time into the future (as always) but the path it takes leads inwards. Literally you can't get there from... |
[
"On a microwave, is there really a difference between the \"Cook\" and \"Defrost\" options for how the microwaves are emitted?"
] | [
false
] | Or is it similar to a toaster, where it only programs how much time to operate? | [
"The difference generally lies in the timing pattern of how they are emitted - they will zap the food for a few seconds, then wait a few seconds, then zap it again, over and over - perhaps not at full power. The idea is to heat the thing up really slowly and not accidentally cook any part of it... so you apply hea... | [
"The metal that exists in a microwave and does not cause problems is smooth. If you put an object like a fork in a microwave, the prongs would accumulate opposite charge until they would arc from one another.",
"You can stare into a microwave because the wavelength of a microwave is ~5 inches and most of the wav... | [
"It is different for each brand and Year made. Newer models can check the humidity in the microwave to determine if the object in question is still evaporating water. Others preform a crude infrared measurement. The better question is, how do microwaves now days have metal trays/racks built into them and not cause... |
[
"Was junk DNA always junk or is it vestigial?"
] | [
false
] | I know that random mutations will produce "nonsense" and assume that at least some of the "junk DNA" we carry can be attributed to that, but I was wondering if some of it are fragments of vestigial DNA from our distant ancestors? If it exists, can we tell the difference between those two categories of DNA and has any o... | [
"There are lots of ways to get junk DNA. Genomes can get bigger in lots of ways, and having extra, completely useless DNA has minimal costs (that is, it’s not strongly selected against); whereas there are not many ways to make genomes smaller without doing lots of harm. ",
"One major source of junk is genome du... | [
"On the other hand, I read that birds and bats independently underwent serious shortening of their genomes, allowing smaller cell nuclei and smaller cells. This allowed bird neurons to get smaller and more densely packed, so bird brains have more neurons by volume -- leading to much higher cognitive performance tha... | [
"The difference for bats is minor - their genome is slightly smaller than most placental mammals but not dramatically so - and that’s mainly because they have fewer transposable elements. Conceivably there’s stronger selective pressure against genome expansion in those species (which of course further supports the ... |
[
"I can't seem to find any academic articles about the sum of all natural numbers being -1/12. Are there any?"
] | [
false
] | null | [
"The sum doesn't equal to -1/12 in the traditional sense (it does not converge), the Ramanujan sum and Cesaro sum are -1/12 for the natural numbers, as is the zeta function at z=-1 which also can be thought of as \"sum of natural numbers\". Why are you looking at academic papers for this anyway? ",
"This isn't a ... | [
"I have to translate an academic article on a controversial topic to a popular piece."
] | [
"Okay. It's not a controversial topic."
] |
[
"If an object is stuck in your body, why are you supposed to leave the object in your skin?"
] | [
false
] | Is it because the wound will grow? I'd think to remove it quickly so that the bacteria wouldn't enter your body | [
"the body forms calcium deposits around foreign objects and basically makes them totally inert and not a threat to your health, there are exceptions like lead bullets near a joint, for example.",
"edit: if you are referring to something like leaving the knife in if you are stabbed, this is meant to prevent you fr... | [
"The wound will not grow, but if, say, you have a piece of wood in your leg, as long as teh wood is there, it is acting as a plug for the blood wishing to be free of your body. When you pull that plug, well the blood will happily leave your body so best to let that happen when safely in a medical facility with plen... | [
"The same concept applies to how a pearl is formed. A piece of sand or other foreign object jabbed into the innards of a clam are covered with layers of necrae until you have a pearl which is quite a bit larger and easier to get leverage on or use its own weight against itself to dislodge."
] |
[
"How many satellites in orbit have human maintenance scheduled compared to those that don't?"
] | [
false
] | There are lots of satellites up there, but how many actually get maintained every now and then? | [
"None.",
"The Hubble Space Telescope was the last operating satellite to be serviced by astronauts. There are no current plans for future manned missions to repair any other satellites.",
"Several groups are trying to work on unmanned methods of docking small satellites onto existing satellites that have run o... | [
"Virtually none of them. Except for incredibly expensive things like the Hubble telescope, it's cheaper to just launch a new one than to send a human crew to repair it. There's been some research into robotic servicing though, but it doesn't look like it's gone very far - ",
"https://en.wikipedia.org/wiki/Space_I... | [
"None? I thought the ISS was still being serviced. Or are the manned missions not planned for maintenance?"
] |
[
"Is the platinum strictly necessary for the hydrogen fuel cell reaction?"
] | [
false
] | The context is I have been asked to make an experiment that ~50 summer campers can do. I thought it would be neat to do the cycle of splitting water into H+O, and then getting power back. However, when I look up instructions for making a hydrogen fuel cell, they all start with 'take 12 inches of plantinum wire', which ... | [
"You might be thinking of an electrolytic cell. For a fuel cell you actually need platinum or palladium. The metal has to catalyze the hydrogen oxidation.",
"Copper or aluminum definitely won't work."
] | [
"Royal Society of Chemistry - ",
"teacher guide to this experiment",
" and ",
"learning outcomes",
".",
"Specific ",
"hydrogen fuel cell education resources",
".",
"The experiment should be fun, but students should also learn. A simple brine electrolysis will demonstrate the principles in a much ea... | [
"No, platinum is used in fuel cells because resistant to oxidation, so it lasts a long time. For your purposes, a normal copper or aluminum stranded wire will do fine. It just wont last for days, not that you need it to."
] |
[
"Can a mutated virus become a new disease?"
] | [
false
] | null | [
"Yes. Accrue enough mutations and all kinds of “fun” things can happen. That’s why we have a diversity of living things (although viruses are not living, they are comprised of molecular components—DNA or RNA—that also determine the genomes of living things). The same process can occur with disease in general (of co... | [
"Yes, for example measles evolved from rinderpest (which is now eradicated)."
] | [
"A disease is defined by its symptoms, or its impact on the health of the host (dis-ease). So, sure... if mutations substantially change the way a virus impacts a host’s health, that means a different diagnostic criteria and a new disease."
] |
[
"What makes it so hard to replace damaged section of spinal cord?"
] | [
false
] | I've Googled around and haven't found a very good answer to this question. What are some of the problems that make it so hard for us to replace damaged sections of a spinal cord? | [
"Let's work the problem for a sec. ",
"A) each spine (and grouping of nerves) is different - person to person.",
"\nIf you were to be able to separate the nerve fibers (think extremely fine microscopic fibres - there are millions, in a group the thickness of a pinky finger), you would have to figure out which... | [
"agree with the above. to grossly overstate the simplicity of the problem, imagine shooting a cannonball through your homes circuit breaker box, then attempting to repair everything back to its proper functional state with your hands while wearing a pair of boxing gloves. such an analogy regarding the precision of ... | [
"Thank you so much for your answer, and I do hope we find a way to make significant progress on spinal repair so that you can one day (soon!) make a recovery.",
"I guess for some reason I thought of the spinal cord as more of a bus - a small number of multi-mode fibers that timeshare. Ridiculous. That's what yo... |
[
"Anabolic reactions require energy, but bond formation releases energy?"
] | [
false
] | I'm confused about Anabolic and catabolic reactions. Anabolic reactions require an input of energy, and form larger molecules. But the formation of bonds release energy. While catabolic reactions form energy, but breaking bonds require energy. Can someone clarify this for me? | [
"While I am not an expert on metabolism, I can tell you that bond creation or destruction can release energy or take in energy depending on whether or not the product is more or less energetic system.\nThis is a ",
"ordinary reaction coordinate",
" which shows the general idea, however a complex biological reac... | [
"ATP is high in energy mainly because of charge locality in the inorganic phosphates. It's irrelevant to discussion, as far as substrates in metabolic pathways is concerned. You use ATP in such pathways, but never do you just drink a beaker full of ATP to get energy.",
"What I mentioned was a generalization of bi... | [
"To form or break down covalent bonds between atoms, there is a barrier called the \"activation energy\" for non-spontaneous reactions given the conditions. Spontaneous reactions go on their own and we will discuss them in a moment. The reason we need to overcome this initial energetic hurdle is that what all rea... |
[
"Why do I still need to wear glasses when using the Oculus Rift even though the screen is well within the range where I can see objects clearly?"
] | [
false
] | I am near sighted, and without glasses or contacts while using the Rift, everything in the game world looks as blurry as if it was real life and I didn't have glasses. I'm not sure if this is a biological or technological question. EDIT: Someone posted this on the forum; I think it is related to the question I am tryin... | [
"Let's address the optics first. Take a look at this:",
"http://imgur.com/kffS5nr",
"E is your eye lens. Point C close and F is far. In order to focus on your retina notice that the light coming from point C have to bend more than point F. The parallel lines are the hypothetical infinity lines and require the m... | [
"Because the lenses in it are designed to focus the image given a \"healthy\" eye. They ",
" make a rift with the appropriate lenses to fit your eye but they don't. Many higher end photo cameras let you replace the view finder to fit your prescription so that you can use the camera without your glasses:",
"http... | [
"Now for the sensation of depth, your brain isn't just using the change in parallax for depth.",
"If something was at your nose you'd have to cross your eyes to look at it no? If it was far away your eyes are essentially parallel. How \"crossed\" your eyes are when focusing, as well as how much it has to squish y... |
[
"During mitosis, how the organelles without their own DNA are replicated?"
] | [
false
] | During replication, what structures are responsible to replicate the other organelles like Golgi Complex, R.E.R., S.E.S., are created? Are the ribosomes responsible for that too? | [
"It doesn't. There's a bunch of them lying around, so each daughter cell will probably end up with enough to start with, and then make more as needed.",
"It's like pouring half a cup of coffee into another cup. You don't spend any time worrying that you will accidentally just pour water out and that all the coffe... | [
"Not a complete answer to your question, but note that cells have multiple copies of each organelle. The ",
"textbook picture of a cell",
" is only drawn with one of each for simplification. The only thing cells mainly only have one of is a nucleus, which is why it is the main thing we focus on when we study mi... | [
"There can be more than one of each type of organelle in the cell before it divides. The cell will split the cytoplasm between the two daughter cells, and in turn the organelles therein. The organelles are replicated during the growth phases of the cell cycle."
] |
[
"Is it possible for a planet to have inconsistent seasons. Like the Irregular Summers and winters in the book series A Song of Ice and Fire?"
] | [
false
] | I understand seasons are dependent on how the earth revolves around the Sun. But could there be such a thing as a planet that changes its axis. Or is this likely a meteorological issue like ice ages and what not? sorry if this question doesn't make sense. | [
"It is on Earth. No reason why eccentricity couldn't produce 'seasons' on a different planet though (I think)."
] | [
"The distance from the sun is WHY the tilt of the rotation axis affects seasons",
"No, it's not the distance, ",
"it's the angle",
".",
"Edit: When I first posted this, it just said \"No it's not\", with no explanation. MCMXCII was probably responding to that version."
] | [
"The distance from the sun is WHY the tilt of the rotation axis affects seasons",
"No, it's not the distance, ",
"it's the angle",
".",
"Edit: When I first posted this, it just said \"No it's not\", with no explanation. MCMXCII was probably responding to that version."
] |
[
"Is it possible to make a rainbow from an artificial light and mist?"
] | [
false
] | Say the flashlight (or any other artificial light source) is inside an empty fish tank and there is a small nozzle connected to a hose giving out a mist of water at a regular rate, would I see a rainbow? Drew a picture of what I'm asking about. If not this way then how? | [
"You will only see a rainbow if the following conditions are met:",
"1) The light source is highly parallel",
"2) The light is sufficiently \"white\".",
"If the light is not parallel, then the various angles of refraction will not contructively interfere into what you recognize as a rainbow. I do not expect ... | [
"A flashlight most certainly will work. The \"constructive interference\" does not require a large beam of coherent light - that is, the narrow band of whatever light source can interfere. The light that doesn't interfere just drowns out the reflected light, but it in no way makes the phenomenon disappear. This can... | [
"Put two pieces of dark masking tape across the front of the flashlight parallel to each other, leaving just a thin slit for the light to shine through."
] |
[
"Astronomers of Reddit: It seems all cool \"large-scale\" events take either billions of years to develop or just a few moments to occur. Are there any fun \"large\" events (galactic?) that occur over more observable timelines (e.g. days, weeks, or months?)"
] | [
false
] | null | [
"On a size scale, no. But on a energy scale, yes. There are these fascinating phenomena known as Gamma Ray Bursts (GRBs). These are the brightest things in the universe, incredibly energetic. There are two classes of GRBs, hard and soft, the name of them comes from the wavelength of the gamma radiation produced. ",... | [
"supernovae are visible over weeks to months.",
"SN 185",
" was visible for eight months",
"SN 1006",
" was visible for three months, disappeared for a while, then reappeared dimmer for another eighteen months.",
"SN 1054",
" was visible in daylight for 23 days, and at night for 642 days.",
"SN 1604",... | [
"Wow, that would be one of the most amazing things I can imagine to witness in person. Though I bet you wouldn't want to be anywhere near it when it happened with all that energy being released. ",
"Have we detected a neutron star being absorbed by a black hole, or is it just a mathematical prediction?"
] |
[
"When we \"feel\" things while dreaming, are any nerves in our body active?"
] | [
false
] | As in, you get poked in the leg while in a dream and feel it. Are nerves in your leg firing? | [
"Your peripheral nerves only fire in response to external stimuli. So the short answer to your question is, no. Say you get poked in the leg in real life, while you are sleeping, your mechanoreceptors (receptors that perceive touch) will activate. This may or may not cause wakefulness depending on a large number of... | [
"It's not a silly question. Typically mirror neurons are associated more with motor movements than touch, but there is some research demonstrating people who feel touch on themselves when they see another being touched. Mirror neurons are active when someone performs a motion, as well as when they observe another p... | [
"Sorry if this is a silly question, but I read once about something called \"mirror neurons\" (I'm pretty sure that's what they were called) that fire when we see someone else being poked. Would these neurons be active during the dream?"
] |
[
"How viable is Replacement cloning?"
] | [
false
] | I read a bit about replacement cloning, the process of creating a clone and performing a lobotomy or head transplant between the original and the clone, totally removing ailments of the body of the original but keeping the same conciseness. Obviously the clone would need to grow to a reasonable size before the procedur... | [
"There isn't a lot of promise at all, in fact there is very little research into this at all, our best technology can't even reconnect nerves currently, otherwise all those paraplegics caused by spinal injuries would be able to be \"fixed\".",
"I don't know what you have been reading, but it isn't current scienti... | [
"Not at all. We cant replace heads or brains. we don't have the ability to reattach nerves, regrow spinal columns that fit/work, etc.",
"I know we've had some luck with head transplants",
"No we haven't. At best we can slap a head on a different body and feed it blood and watch it die sooner than later. The oft... | [
"At this point it would be easier to contemplate organ transplant in specific organ failure, or standard of care for disseminated disease (ie best current chemotherapy for widely metastatic cancer). Head transplants are ",
"in fact possible",
" if done carefully to ensure the severed donor head is nourished, ox... |
[
"Is there any possibility, however small, that two people are genetically identical?"
] | [
false
] | null | [
"Exactly identical, extremely unlikely. Nearly identical -- that's what monozygotic twins are."
] | [
"We don't have human clones at the moment. It is possible that there are no mutations for two monozygotic twins but that is very unlikely. Normally there are hundreds of genetic differences. "
] | [
"That's what I was thinking about, twins are very similar genetially but what about 2 that are identical? Like clones of eachother?"
] |
[
"how does time dilation work when already moving at a certain speed?"
] | [
false
] | [deleted] | [
"All that matters is the relative velocity of the two observers. How fast is one moving relative to the other? There is no fixed preferred reference frame."
] | [
"Right. This can be a tricky thing to get your head around, so it's worth rephrasing a few different ways.",
"In our universe, there's no such thing as \"base speed\". All motion is relative to something else. Similarly, nothing is ever \"at a full stop\", in an absolute sense. We can pick whatever reference fram... | [
"When already moving, it's more easy to increase the existing relativistic effects.",
"I checked that with this relativity calculator: ",
"http://www.1728.org/reltivty.htm",
" ",
"Going from 0 to 0.866 c , the relativistic change factor becomes 2",
"Then doing another acceleration identical to the first o... |
[
"What would happen if the oceans were uniformly 10 feet deeper?"
] | [
false
] | What would happen if the oceans (and other great bodies of water) were uniformly 10 feet deeper? I assume water would fill that void due to matter's desire to be at a lower level of potential energy... If so, would that affect the availability of water to the inland via rain? Thoughts? | [
"Is this a change that's supposed to happen currently, or is it just an alternative history?"
] | [
"An alternate history with the only variable being the depth of the ocean floor"
] | [
"I am restating your quest to add some assumptions to make the question more tractable.",
"How would the hydrologic cycle be affected if additional water, sufficient to raise sea level 3m, were added.",
"The additional relevant assumptions are the water did not come from changing climactic forcing, and it is no... |
[
"When I do arithmetic/math, am I actually performing the calculations in my head, or am I pulling the results from old examples in my memory?"
] | [
false
] | [deleted] | [
"Read this askscience post about ",
"when I look at five apples, do I know it's five apples because I count them quickly, or because I memorized what five apples looks like?",
"The answer is pretty similar. For simple arithmetic, you probably memorized most of the answers. Personally, I don't calculate 2+2=4,... | [
"That makes sense, thanks!"
] | [
"You might not use it as often as I have, but ",
"Alt+0215\n",
"yields '×,' and helps to avoid accidental italics. "
] |
[
"How do we know that the Universe is not already collapsing?"
] | [
false
] | I basically understand that: a) the observable Universe is expanding; b) that observable Universe is roughly 13.5 - 14 billion years old; c) that the distance to edge of the observable Universe is approximately 46 billion light years; and d) the light we are observing from the edge of the observable Universe has been t... | [
"We know that the universe is not only expanding, but the rate at which it is expanding is accelerating.",
"We have several independent observations of this. The simplest is the use of 'standard candle' supernovas. A Type IA supernova happens when a white dwarf star has a close companion star. The white dwarf col... | [
"So what you're asking is how do we know that the universe as a whole (outside the observable universe) isn't collapsing? ",
"Short answer, we don't. But as ChazR explained, we know that the observable universe is expanding, and based on the principle of homogeneity (the universe is the same in all locations) a... | [
"I remember hearing that the CMB will be detectable untill about year 1trillion. And the ligth of that CMB travelled 1trillion light years to reach us ofcourse."
] |
[
"Acupuncture blocks pain in mice via adenosine signaling?"
] | [
false
] | I guess my question is whether anyone has critiques of this paper's methodology? Knowledge of replication? Knowledge of the similarity of adenosine signaling in pain systems between rodents and humans? | [
"OK, so I just read through the paper. I personally have not worked with A1 receptors, though I have with A2A, but only in the CNS. I have done quite a bit of work with antinociception, though again, not in terms of the A1 receptor. ",
"Overall, I think the paper is very straightforward and makes sense. It appear... | [
"While I agree with your general sentiment, I'd be cautious about saying",
"People wouldn't be doing this for thousands of years if it didn't do something.",
"People can be a bit slow."
] | [
"\"Sticking needles somewhere\" without referring to ",
" and meridians ",
", it's \"irritating the skin\". In the same way that chiropractic without subluxations and energy flows no longer is \"chiropractic\" but \"physical therapy without a license\".",
"Ignoring that and still using the terms \"acupuncture... |
[
"How true is the statement, \"Beer before liquor never been sicker, liquor before beer you're in the clear\"?"
] | [
false
] | null | [
"Mythbusters busted this a while back.",
"\"Explanation: There are certain immutable laws when it comes to getting tanked. For instance, the only cure for drunkenness is time (not coffee). But the popular theory that consuming both beer and liquor will make you feel sicker isn't quite as sound.",
"It's true tha... | [
"This is more of a mental thing rather than a physical thing. Allow me to explain:",
"6 beers and 6 shots will get you the to the same level of drunkness (let's assume this to be true). ",
"Let's start with liquor first, then beer. So at this point you're reasonably drunk, and drunk people want to keep drinking... | [
"This is only true because of how long it might take you to consume a beer.",
"Actually, the carbonation in beer can increase the rate your body absorbs the ethanol. Conversely, the high alcohol content of spirits is an irritant to the epithelial lining in your intestines, which causes the body to more slowly abs... |
[
"What have been the implications/significance of finding the Higgs Boson particle?"
] | [
false
] | There was so much hype about the "god particle" a few years ago. What have been the results of the find? | [
"The particle itself was never of any particular relevance, except for potential weeding out potential grand-unified theories. The importance of the discovery of the boson was that it confirmed that the Higgs FIELD was there, which was the important thing. For about the last 50 years, particle physics has constru... | [
"Whenever you mathematically \"ask\" the Standard Model for an experimental prediction, you have to forcibly say, in math, \"but don't consider up to infinite energy, stop SOMEWHERE at high energies\". This \"somewhere\" is called a \"cut-off\" you have to insert. ",
"If you don't do this, it'll spit out a gobbl... | [
"High level physics explanation....contains word gobbledygook. Well my life is complete now."
] |
[
"How is it that the masses of a proton and electron are extremely different even though they each are comprised of 3 quarks?"
] | [
false
] | null | [
"These",
" particles are elementary, according to the Standard Model. All others are composite particles made of these fundamental building blocks."
] | [
"Holy crap! For every stone unturned, two more are revealed. Thank you"
] | [
"Electrons are elementary particles; they are not made of quarks."
] |
[
"How do paternity tests work?"
] | [
false
] | Specifically, what markers are used in paternity tests? SNPs? SSRs? I heard that they use 15-20 markers. I guess these are SSR alleles. I heard that newer tests use hundreds. Would newer tests use SNPs? | [
"Usually STR typing methods are used. They could use multiplex PCR amplification, then the STR alleles are separated by capillary electrophoresis to determine the length of the STR (how many copies of ATGC that marker has.) So a result of D21S11 17/20 means one chromosome has 17 repeats and the other chromosome ha... | [
"Usually STR typing methods are used. They could use multiplex PCR amplification, then the STR alleles are separated by capillary electrophoresis to determine the length of the STR (how many copies of ATGC that marker has.) So a result of D21S11 17/20 means one chromosome has 17 repeats and the other chromosome ha... | [
"Each lab or testing kit varies in the number of DNA markers it uses (the more markers used, the higher the cost, but more reliable the outcome). Currently, the standard practice is to use STR's (Short Tandem Repeats), such as D21S11 or TH01. (Often SSR and STR are used interchangeably). However SNP tend to be used... |
[
"Is there an order bias is nature?"
] | [
false
] | Is there a bias in physics towards order? Are statistics useful on the quantum scale? If there is a bias towards order, would probability be affected? | [
"Is there a bias in physics towards order?",
"No, quite the opposite. There is a definite bias towards ",
", and it's called ",
"the second law of thermodynamics",
". ",
"In very simple layman words, it says disorder (technically, ",
") never decreases (and it actually tends to almost always increase) u... | [
"But what about perceiving order? Is there a bias in seeing order where there isn't? "
] | [
"Do you talk of ",
"this cognitive bias?",
" "
] |
[
"How much genetic diversity is there in the sperm from a single donor?"
] | [
false
] | Over 250 million sperm get released with an ejaculation, but given they all come from the same host, what is their genetic diversity? How many (viable) different combinations of genes are possible in the 23 human haploid chromosomes? For instance, on human , which is one of the largest, there are thought to be only 1... | [
"Direct quote from ",
"here",
":",
"Probability says yes. [In reply to the question: Is every sperm unique?] During meiosis and due to independent assortment at metaphase I, the homologous chromosome pairs (one from Mom and one from dad for each type of chromosome) line up together. The first time the cell di... | [
"Eljew's post is quite transparent, so we can answer that with No. Recombination of chromosomes makes this process quite a lot more complex and gives it much larger diversity. ",
"Wikipedia: Meiosis"
] | [
"From my post, perhaps you meant to reply the post below mine?",
"That's about 8 million different ways. But that is not the whole picture. Because early in meiosis, when the pairs first get together before metaphase, they trade pieces of themselves, i.e., a piece breaks off of each and switches places. This is k... |
[
"Lung Inflation Pressures?"
] | [
false
] | I was just curious what kind of pressure the human lungs can hold, such as if an air pump was used to inflate the lungs while all exit paths for air were blocked. Additionally, what kind of effect would the overpressurizing of the lungs have on a live human? | [
"Barotrauma in the lungs tends to occur above 45cmH20 in ventilated patients as far as we know. This number can be drastically lower in a patient with highly increased compliance like a COPD patient, or someone with an alpha-1 anti-trypsin deficiency(these patients have floppy lungs, think like an elastic that's b... | [
"Teedy's correct here.",
"However, I think your question may be a bit confused. As a reformed diver, the barotrauma angle is not what is causing nitrogen narcosis.",
"Barotrauma occurs during positive pressure ventilation. That is, a positive pressure is applied to the airway by a machine. The distending pressu... | [
"Teedy's correct here.",
"However, I think your question may be a bit confused. As a reformed diver, the barotrauma angle is not what is causing nitrogen narcosis.",
"Barotrauma occurs during positive pressure ventilation. That is, a positive pressure is applied to the airway by a machine. The distending pressu... |
[
"What are the actual mechanics involved in metamaterial cloaking? How is the refractive index varied to achieve the effect?"
] | [
false
] | I'm talking about stuff like and . How does the refractive index vary through that ring when the cloak is present? Does it increase radially or what? I've read a bit on the subject and yet all I can find is vague explanations like "metamaterials bend light in ways previously thought impossible". I know the basic ide... | [
"Metamaterials are capable of having negative indices of refraction. The refractive index or positioning of the metamaterial depends on the geometry of the object being cloaked, unless you opt to cloak a bubble in which your object can fit. "
] | [
"Yeah, and I'd like to know how exactly the refractive index depends on the geometry of the object. I'm not totally averse to mathematical explanations, I am a physics undergraduate after all, haha"
] | [
"Forward that information my way, as I haven't found any specific mathematical information on varying the refractive index. I've only been reading publications on acoustic metamaterials, though all the mathematical models used are nearly identical "
] |
[
"What kind of toxic substance looks like coffee?"
] | [
false
] | null | [
"I don't know what specifically it could be, but they say it looks like instant coffee - so it looks like a fine, dark brown power. Many purified, dried compounds look like a fine powder, and contamination in the process could introduce discolorations that could make it appear black or brown (or maybe it just got b... | [
"What I'm guessing they are worried about is that the thieves would mix the substance with coffee to produce a greater volume of less pure coffee. Much like cutting cocaine. This would mean it would only have to be black and powdery?"
] | [
"I don't get it--if something's toxic and it's so dark that it looks like coffee, surely it wouldn't have the same smell as coffee?"
] |
[
"If light is a wave; what is the medium in which it travels?"
] | [
false
] | Similar to sound/vibrations which travel through matter such as air. What is the medium that light travels through if it is also wave? I am also confused about why gravity affects light unless gravity has an effect on the substance that light is moving through. Does a black hole work similar to vibrations moving thro... | [
"Light doesn't require a medium to travel. Light is actually fluctuations in the electromagnetic field which is present everywhere and it's not the same kind of wave as sound waves. Sound waves are pressure waves which obviously require a medium to compress and move through.",
"As for gravity affecting light, thi... | [
"An EM wave is a field fluctuation. There's no such thing as background noise in the field, you can get other fluctuations but that isn't noise except for when you're trying to measure a specific wave.",
"Gravity has no effect on EM fields beyond the curvature of spacetime which a photon must follow."
] | [
"No light doesn't travel fastest through a vacuum, light always travels at a constant speed no matter the circumstances or medium. Photons always travel at c, what makes light appear to go slower in a medium is photons are constantly absorbed by atoms and other particles then reemited; this causes the photon to tak... |
[
"Can you actually change how resistant my body is to cold weather by doing physical activities in the cold? If so, what are some of the best ways? and what actually changes in the body?"
] | [
false
] | Apparently doing physical activities outside in cold weather seems to make me more resistant to cold weather. I can be outside in lower temperatures without being uncomfortable. Assuming this isn't just a placebo effect or myth: | [
"Wikipedia",
"In order to maintain performance across a range of environmental conditions, there are several strategies organisms use to acclimate. In response to changes in temperature, organisms can change the biochemistry of cell membranes making them more fluid in cold temperatures and less fluid in warm temp... | [
"Muscles ought to protect you better than fat I think. Especially when they're vibrating!"
] | [
"Layers of fat helps greatly in retaining warmth. This is why seals and whales in the arctic ocean have such huge layers of blubber. "
] |
[
"How does buoyancy work on a molecular level?"
] | [
false
] | I've been trying to find the reason that less dense substances float on more dense substances, but every explanation I find is insufficient. One common explanation I hear is that when an object is immersed in a fluid with greater density, the pressure at the bottom of the object is greater than the pressure at the top.... | [
"\"Kinetic theory\" may be the term you're looking for, if that helps you in future googling.",
"So, \"pressure\" is just the molecules smacking against each other, and applying forces to each other when they collide. The other main force they're feeling is gravity.",
"If these forces don't cancel out, then the... | [
"Thank you! This is exactly the kind of explanation I was looking for. And I'll remember kinetic theory if I want to look this up in the future."
] | [
"Buoyancy is a practice of displacement. ",
"Water, on a molecular level, is observed to be various short segments of H2O molecules combined in chains, laying flat against one another longitudinally. Because they are very thin, they do not compress easily (or much at all). The result is that any object placed on ... |
[
"How does beta decay transform a proton into a neutron and other particles? Aren't neutrons more massive?"
] | [
false
] | I was researching about fusion, especially with Hydrogen into Helium and was wondering how the beta decay even occurs/happens when neutrons are larger than protons yet somehow the protons transform into neutrons and other particles? | [
"In a beta-plus decay, it's not a single neutron which is decaying into a proton, it's an ",
" decaying into a new species.",
"While a free proton can't decay into a neutron, beta particle, and neutrino due to energy conservation, an entire nucleus can decay to a species of lower mass by converting one of its p... | [
"An isolated proton is less massive than an isolated neutron yes, but a bound state of a neutron and proton is less massive than two isolated protons. ",
"This is due to the binding energy of the proton and neutron. Remember E = mc",
" so as the two isolated protons had more mass, they had more potential e... | [
"This is the key, mass doesn't work the same way as your intuition expects at the sub atomic levels. The mass of a proton and a neutron in a hydrogen nucleus is less than the mass of the two separately because the bound state has a lower energy level than the unbound state. Any state can transform into a lower ener... |
[
"What are Vitamins? Are they forms of energy? How are they beneficial to you, in technical terms?"
] | [
false
] | [deleted] | [
"Vitamins are usually co-factors for biochemical reactions. This means that they assist enzymes in facilitating reactions. While you may be able to say that they technically aren't required for a reaction to take place, they absolutely are required for the reactions to occur properly in a biologically reasonable am... | [
"Your body is made of lots of things, all with their own jobs. Proteins are like the jack-of-all-trades though, in that they fill the gaps left by the other biomolecules. They also have what is probably the most important job of any of the biomolecules. They catalyze the reactions that allow the cell to function an... | [
"Literally vitamin means \"vital amine\""
] |
[
"Does the DNA/RNA/Proteins/metabolites in the food we eat affect us in any way?"
] | [
false
] | apart from energy and vitamins and all that jazz... can some carrot proteins or Rna enter my cells and affect how they work? | [
"The other comments havn't really answered your question. Luckily, I remember a newscientist article from a while ago. ",
"Here it is",
". So basically, yes, there was evidence that plant dna you eat can get into the blood and have certain effects through RNAi. HOWEVER, since then and actually before then, ",
... | [
"right on , thx... acting only through RNA makes a lot of sense, especially rnai since it is basically already digested into smaller bits"
] | [
"This is how viruses work! They can integrate their genome into the host like HIV and cause serious detriment to the host. ",
"However, you're unlikely going to suffer non-host interactions. I'm certain that you've eaten plant viruses on an immeasurable scale throughout your lifetime."
] |
[
"Can someone explain to me what they mean when theorizing that our universe is either open, flat, or closed?"
] | [
false
] | I just cant seem to wrap my head around it. What am I picturing in my head when they say our universe is flat? Am I picturing a piece of paper? What about an open universerse? Am I picturing a bowl etc. I find any way i look at it, it seems odd. Or am I just not understanding this correctly altogether? | [
"The terms open and closed in this context are actually very unfortunate misnomers, since the terms open and closed mean something different in the proper mathematical setting. For instance, a flat universe can be either open or closed (in the mathematical sense). So your confusion is not surprising.",
"In the Ro... | [
"1) When for instance talking about positive curvature, (sphere) why am I only picturing the 'surface' rather then the entire sphere as the universe in three dimensional space? The 'entire' universe would be the surface and everything within it would it not?",
"It is easiest to visualize manifolds as embedded in ... | [
"What a response. Thank you very much. I have been watching a lot of Lawrence Krauss lately and every time he talks about this it bothered me. If you don't mind I have 2 (hopefully) simple questions.",
"1) When for instance talking about positive curvature, (sphere) why am I only picturing the 'surface' rather th... |
[
"Where could I find data on solar activity for around the last century?"
] | [
false
] | [deleted] | [
"Sunspot numbers could work, they're an indicator of solar activity, am I right?"
] | [
"SOHO?"
] | [
"I have no idea how to even begin acquiring the data from their website."
] |
[
"What causes the sonic boom at mach 2+?"
] | [
false
] | From what I understand, at mach 1, the speed of sound, a sonic boom is caused when an object is traveling as fast as the sound waves propagating away from the object. The waves build up an immense pressure and collapse on themselves, creating a "boom". However, this sound can be heard each time an object hits a multipl... | [
"A sonic boom doesn't have anything to do with multiples of Mach 1. It's heard when an object travelling at ",
" speed above Mach 1 passes by. At least, it's heard if the object is far enough away that the shock wave doesn't just destroy your ears. ",
"Things like planes, missiles, etc. moving supersonically... | [
"Hmm...you're right...my mistake. I was basing it off of an intermediate knowledge of physics and a segment in ",
"The Right Stuff",
". It seemed like he \"boomed\" again at Mach 2, but it appears to be a misunderstanding on my part. There is no second boom.",
"Thanks for the answer."
] | [
"It think it is possible to get multiple fronts shed from an aircraft exceeding Mach 1. The first front sheds from the nose. Other surfaces such as wing roots and eppenage will also shed Mach fronts. These fronts are not a function of multiples of Mach 1, but more a function of the angle of the protrusion that gene... |
[
"How far back in time could one go before disease immunity becomes a problem?"
] | [
false
] | With all the time travel movies coming out lately, I've been thinking about the practicality of time travel (ignoring time paradoxes). The most obvious obstacle is that we are immune to diseases from the present that people in that past aren't immune to and vice versa. So, how far back can one go (from October 2012) b... | [
"Ignoring travel in time, you can travel to other parts of the world in the ",
" and have potentially fatal issues with local diseases like dysentery."
] | [
"About the late 1800s for a person in the US if considering smallpox which you have no immunity to. You will also be susceptible to most of the pandemic strains of flu that occurred before you were born. "
] | [
"Nope. Immunity to smallpox happens on an individual basis. It was an endemic disease of childhood in Europe -- most people who survived to adulthood had contracted smallpox as children. That's why the Europeans were mostly immune.\nHuge numbers of Europeans still died of the disease, though -- just not on the scal... |
[
"Where does the fat go when we \"burn fat\"? Is it excreted through digestion, sweat, re-purposed, etc?"
] | [
false
] | null | [
"Complete digestion of fatty acids results in energy, water, and carbon dioxide. You breathe out the carbon dioxide, and urinate/sweat out the water. Flatulence is made up from gases you swallow, and gases produced by bacteria in your gut while they digest their own food, most typically carbohydrates but sometimes ... | [
"So if carbs make me fat, then does this mean I'll \"Toot\" out the carbs?"
] | [
"If you use something for energy, i.e. turning it into ATP for use in cellular processes, the waste is either going to be carbon dioxide you breathe out, or potentially some intermediate that may eventually get filtered out by your kidneys. Gas you make from cellular metabolism exits through the blood and then lung... |
[
"What material could produce the X-ray florescence spectra for this historical artifact?"
] | [
false
] | Hi there, Science! I'm a historian doing archaeology, which means I'm doubly out of my element (so to speak). I've been looking at glass beads that were dropped in the outhouse of a New England boarding school sometime in the 1860s. Most of them are simple glass beads, perhaps used for teaching girls crafts, but I've g... | [
"So the timeframe you're thinking about, and the large amounts of sulfur make me think of hardened rubber. Something like Ebonite, possibly with a mineral filler. These kinds of materials were often used as a cheap substitute for jet. The Ebonite would account for the low density and the presence of sulfur, and the... | [
"Archimedes method density measurements are pretty simple to do, inexpensive, and fairly accurate. ",
"Or, since it's a bead and you have the dimensions, calculate the volume of an ellipse and use the weight you have. It should get you into the ballpark."
] | [
"Thanks! This bead had been sorted in with glass beads, so the handful of people who touched this bead didn't notice any appreciably different physical properties from glass. I think it was cool to the touch, but that might have been a bit of observer bias. It wasn't sticky, like a bone bead that I also identified,... |
[
"How does Folding@Home prevent intentional sabotages?"
] | [
false
] | Since they are getting these calculated data from anyone, couldn't some bad actors just intentionally put in wrong "answers" to their calculations? Thanks! | [
"The calculations are split into separate \"work units\" and each work unit is provided to multiple users and the results from each user are compared. The outcome is only submitted to the researchers once there is consensus from the users on what the outcome is.",
"This doesn't just protect against intentional sa... | [
"As Rannasha said, multiple users receive the same project as a fail-safe against natural, everyday computational errors, including the rare person with an unstable computer.",
"As for malicious projects... project control is tightly regulated and still must be screened before it's allowed for widespread distrib... | [
"The two aren't comparable though. Bitcoin (and similar systems) are based on decentralized decision making, where someone with a large fraction of the computer power can exert control over the entire system.",
"Distributed computing projects like F@H aren't decentralized at all. There's a central authority that ... |
[
"Most baby animals are relatively quiet, while our babies wail like fire engines. How could early humans or hominids deal with this?"
] | [
false
] | [deleted] | [
"If you want an evolutionary standpoint, look at our closest relatives, all other great apes hold their babies almost constantly. That human babies cry because the need to be held is also backed up by the protein-fat-carb ratio in human milk which is set up to promote growth, assuming that warmth will be provided b... | [
"As someone who has done research involving non-human primate infants (specifically Titi monkeys), I can tell you from experience that they can be quite loud indeed when stressed or separated from their mothers. The Human Intruder Paradigm (HIP) is an study method that observes the different infant stress responses... | [
"Sup. ",
"NYT 2005: A Darwinian Look at a Wailing Baby",
"."
] |
[
"Do we know anything about the distribution of dark matter?"
] | [
false
] | Do we know how dark matter is distributed in space; like does it cluster around certain astronomical bodies or is it more loosely distributed? | [
"as far as we can tell, dark matter is pretty sparsely spread out and doesn't tend to concentrate so densely as normal matter does (in planets and stars and such). This is one of the reasons it's so hard to accurately observe, because while there is a lot of it, due to the fact that it's spread out pretty evenly on... | [
"Not an astrophysicist but we think that dark matter is concentrated around large “normal matter” objects and areas such as galaxy clusters. We actually discovered dark matter because of the fact that there was not enough matter in galaxy clusters for them to stay together(thus the mystery mass)."
] | [
"Yes, we do, at least in theory. On galaxy scales, dark matter is expected to form ellipsoidal (rugby ball shaped) haloes with a ",
"specific density distribution",
". For massive galaxies, this prediction has been directly confirmed through gravitational lensing observations, but for the much more common dwarf... |
[
"Why can't I sleep with my eyes open?"
] | [
false
] | [deleted] | [
"don't your eyes usually roll back though so your pupils don't get any light? People I've seen with their eyes open while they sleep only have the whites showing because their pupils are rolled back. "
] | [
"I don't think so, no. Eyesight goes through the thalamus and the thalamus more or less controls what's 'promoted' to consciousness, so it could just ignore what your eyes are sending it. ",
"That, and there's people out there who sleep with their eyes open. I've been told I sleep with mine half open, so I'd i... | [
"I had bells-Palsy when half of your face is paralysed. I slept with one eye open for two week, creeped my boyfriend out a bit. But didn't seem to effect my sleep."
] |
[
"How does long-term alcohol abuse lead to cirrhosis?"
] | [
false
] | I have seen a figure that displays a pathway of alcoholic liver disease leading to cirrhosis annotated with certain probabilities. On that way the first step is fatty liver. Is fatty liver always a requirement to develop alcoholic fibrosis/cirrhosis? Can a fibrotic/cirrhotic liver lose its fat again and look like a nor... | [
"Cirrhosis is damage. Scar tissue. Your liver does not function in affected area's. And is not going to ever again.",
"Without alcohol you can still get ''nonalcoholic fatty liver disease'' that eventually can lead to cirrhosis and liver failure. But it can be cured.",
"https://www.northshore.org/healthy-you/f... | [
"More about fatty liver and cirrhosis:",
"One of liver basic functions is to store energy, one pathway to it is transforming sugar (and ethanol) in fat. \nOnce you fat storage/usage is skewed, the liver keeps producing and storing fat, which leads to chronic inflammation. ",
"Alcohol, hepatitis virus B and C or... | [
"Absolutely true. I have an obese family member with 25 years of sobriety AND cirrhosis. Quitting drinking is the first step, not the only step."
] |
[
"Why do we bob our heads to music?"
] | [
false
] | Something that I've always observed is that almost everyone either bobs their head or taps their fingers/feet to music. Is this a response learned through observation of others when we are young or is there something else in play here? | [
"I am going to contribute to this question cause this is something I've been thinking about as well: why do we dance?",
"Are there other animals that move rhythmically to music? I imagine that the enjoyment of dance could possibly be attributed to evolutionary mating rituals (flaunting of fitness etc.), but how i... | [
"This question comes up like once a month or so. ",
"The tl;dr answer is no one knows, so speculate away.",
"The more nuanced version is that from a young age humans enjoy music, and react to it in a way that appears to be unique among animals. Dancing birds have become more popular after a certain cockatoo s... | [
"I am not an expert. I can only provide what I have read, but I will provide sources. It appears what you describe is definitely more than learned behavior. From Oliver Sacks' \"Musicophilia\"---",
"\"...'In every culture there is some form of music with a regular beat, a periodic pulse that affords temporal coor... |
[
"Why when I'm squeezing zits on my face do I need to sneeze?"
] | [
false
] | null | [
"This is a question that can only reliably be answered by your doctor."
] | [
"Hello,",
"We can't speculate about this here."
] | [
"Understandable. Could you point me in the right direction please? ",
"Thank you :)"
] |
[
"Why are there so many people with severely impaired vision?"
] | [
false
] | It got me thinking, why are there such a large number of people who can hardly see a metre in front of them without glasses/contact lenses? Shouldn't this have given a great survival disadvantage and so a pretty much fool proof natural mechanism should have evolved? Also, is severe short sightedness this common among o... | [
"This happens ",
" we have glasses and lenses and generally an environment which doesn't greatly prevent individuals with bad eyesight to procreate.",
"If we were still living in the savannas as hunter/gatherers, I bet most of these people will quickly become lion/worm food. I think your problem is that you und... | [
"This is outside my field, but my understanding is that it's currently not well understood. There is some evidence, however, that exposure to lots of sunlight prevents myopia. (See, in particular, ",
"this",
" study.) The reasoning is that because we spend much more time indoors these days than we did many t... | [
"Also this one: ",
"Light, literacy and the absence of ultraviolet radiation in the development of myopia",
"."
] |
[
"Does the movement of astronauts effect the trajectory of their vehicle?"
] | [
false
] | I've seen them using the bulkheads to kick off of to move around inside. Does this effect their trajectory moving through space or are they moving fast enough that they don't need to account for the force? | [
"It would, but the amount would be minuscule due to the mass difference between the astronaut and the vehicle.",
"Then, the astronaut has to STOP eventually (by hitting the opposite wall at least,) which imparts nearly all of that momentum back. Again, the amount is so minuscule that it barely makes a difference... | [
"Yes, you will move. But the combined ship-person system will not change velocity or direction due to your push off. Which is the point.",
"This is highly misleading, of course the center of mass of person+vehicel will not change direction or velocity, but the person and the space ship will.",
"The question was... | [
"which imparts nearly all of that momentum back.",
"It should impart all of the astronaut's momentum back eventually if it is a closed system."
] |
[
"If the earth is 4.5 billion years old, why isn't the earth eroded flat with the deposits ending up in the worlds oceans?"
] | [
false
] | [deleted] | [
"These sections are literally floating atop immense seas of molten rock and magma. ",
"This is flat out wrong - the mantle is almost entirely solid rock (~99% solid by most estimates). It can behave somewhat plastically on geologic timescales is all. Only the outer core is liquid, and that is ~3000 km beneath the... | [
"These sections are literally floating atop immense seas of molten rock and magma. ",
"This is flat out wrong - the mantle is almost entirely solid rock (~99% solid by most estimates). It can behave somewhat plastically on geologic timescales is all. Only the outer core is liquid, and that is ~3000 km beneath the... | [
"Yep, if you scale a basketball up to the size of the Earth, Earth is flatter."
] |
[
"ПРИНЦИПЫ РАЗМЕЩЕНИЯ КЛАПАНОВ"
] | [
false
] | null | [
"oil"
] | [
"oil"
] | [
"medecine"
] |
[
"Is there any physical or observable evidence that substantiates the Integrated Information theory of consciousness?"
] | [
false
] | I was wondering if any neurologist know if there is any physical or observable evidence that substantiates the ? A follow up if there is, is there a particular theory of consciousness most neurologist prescribe to? Do this models apply outside of humans - ie is consciousness considered a spectrum by neurologists? | [
"Made this account to answer the question (broke the reddit addiction once...). I work with the IITC, and would point to the work of Massimini and colleagues ",
"Science, 2005;",
" ",
"Science Trans. Med, 2013",
". These papers are behind the paywall, but I'll summarize them below.",
"Massimini, while w... | [
"My University has a Nature subscription but I guess STM isn't included with it.",
"Can you give some details about the complexity test? I see in the abstract that they \"compressed the spatiotemporal pattern\" and measured their \"algorithmic complexity\". Do you know what kind of mathematical operations they ... | [
"They performed source localization, converted that to a binary signal of significantly activated sources vs non-significantly activated sources, and calculated the lempel-ziv complexity (lz complexity can only be computed on a binary signal)."
] |
[
"Several people have linked me to a website that claims to disprove evolution. Can anyone destroy those arguments in an organized way?"
] | [
false
] | null | [
"Try the talkorigins website - they specialize in this sort of debunking and have a massive FAQ about all sorts of creationist claims."
] | [
"Hi there. Your question isn't really appropriate for AskScience. The question is certainly scientific, but frankly, stuff like this gets exhausting for panelists. ",
"Nothing is ever 100% certain in science, but until you see it on the front page of every newspaper on the planet, go ahead and assume that anyone ... | [
"thank you!"
] |
[
"Will the precautions that we are taking against COVID-19 affect the infection rates of other diseases?"
] | [
false
] | null | [
"Hi Audiblespoon571 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... | [
"Medicine"
] | [
"‘Medicine’"
] |
[
"How big can a rocky planet get? Is there a limit, and if so, what enforces that limit?"
] | [
false
] | In Alan Moore's classic comic , the final chapter takes place on a rocky planet described as being "the size of Jupiter". The gravitational forces on this planet are said to be so strong, any human not wearing a special shielding suit is instaneously crushed into a paper-thin puddle. When I read the story, that planet... | [
"Above a certain size, given ambient conditions (like radiation pressure, light intensity from the star, etc), the planet will become massive enough that it starts capturing hydrogen gas from the interplanetary medium, and becomes a gas giant. Where this happens isn't precisely known, but it's roughly 10x Earth mas... | [
"But if it ends up as a hot Jupiter, it will eventually lose all it's gas and again become a rocky planet. The question is though, could a planet with the mass of Jupiter, but with no gas, be a solid planet or would internal heat be enough to keep the surface liquid?"
] | [
"Thank you! I had completely forgotten about the interplanetary gaseous medium. It's so easy to think of space as empty, when it really isn't, even less so during the planetary formation phase."
] |
[
"What exactly is fire?"
] | [
false
] | null | [
"From the legend himself - ",
"Feynman explains Fire"
] | [
"It's the rapid oxidation of a combustible material. Combustion is an exothermic reaction so thermal energy is released. From what I learned in high school chemistry the light emitted from a fire is caused by electrons falling from a higher energy state in the material being burned. Different colors are emitted bas... | [
"Feynman's explanation of how trains stay on the track and turn blew my mind: ",
"http://www.youtube.com/watch?v=WAwDvbIfkos"
] |
[
"Are there any animals that do not need to sleep?"
] | [
false
] | null | [
"Many fish and whales will sleep with only one half of their brain, such that the other half can remain alert for danger (for ",
"dolphins",
": left side of brain sleeps so they will swim in a circle with their left eye on the outside, watching for predators)"
] | [
"The current scientific consensus is: No.",
"There is some debate on this topic (primarily from Jerome Siegel, who likes to play devil's advocate). However, ",
"this paper",
" is a very good recent review and concludes that the evidence for any animal ",
" needing sleep is very weak. Every species that has ... | [
"This is true for whales and some other marine mammals (e.g., dolphins and fur seals), as well as birds and possibly some reptiles. I'm not aware of any real evidence for unihemispheric sleep in fish, though it may very well exist. In general, sleep has not been well studied in fish."
] |
[
"If nothing can exceed the speed of light, how can \"Energy=Mass times the Speed of Light squared\"?"
] | [
false
] | null | [
"Because it needs to be scaled appropriately. Also, the units aren't correct in that equation."
] | [
"I'm aware of the notion that some forms of light can actually move slightly faster than the speed of light (basically by by being pushed by light behind it)",
"What? That's not true.",
"c",
" is just the appropriate scaling factor - it doesn't represent a mass moving at velocity c",
"."
] | [
"c",
" is just a ",
"constant of proportionality",
" - it doesn't represent something moving."
] |
[
"A friend found what looks to me like a dinosaur tooth fossil at the bottom of a bucket of arrow heads. They bought the bucket at an auction. Anyone able to verify?"
] | [
false
] | Here are the only photos I could get of it. , , | [
"No that is not a tooth. It is sea bottom fossil. The shape is cone or ",
"Here is an identifier page for fossils. ",
" ",
"Look at the tooth or horn shape section. "
] | [
"This is a fossil solitary rugose coral (",
"http://www.palaeos.org/Rugosa",
"). You've got a couple of good pix of the septal distribution, but I can't ID the genus with the pictures shown (usually, you need thin section to ID these buggers)."
] | [
"I think you nailed it!! It was found in Kentucky too. You win the internet tonight. "
] |
[
"When I'm resting/falling asleep, I will \"see\" bright flashes of white when I hear a sudden, loud noise. Why is this?"
] | [
false
] | null | [
"Look up Exploding Head syndrome. I promise I'm not lying about the name. It's a condition that causes symptoms very similar to what you are describing. The only reason I know of this is that I had to do a project on this very disorder a few years ago in college. Good luck!",
"Wikipedia Link: ",
"http://en.wiki... | [
"Happens to me, also. I assumed the loud noise provoked the startle reflex, which made me suddenly squinch my eyes tightly closed for a moment, which created a \"flash\" artifact. (like pressing on your closed eye as a kid made you \"see\" fireworks)",
"Squinching my eyes in the dark without the noise also prod... | [
"I have read about something called exploding head syndrome. Check out this wikipedia article about it: ",
"http://en.wikipedia.org/wiki/Exploding_head_syndrome",
"\nI would say that it fits your description quite well."
] |
[
"Is it possible to make gyms into big power plants, where the machines that people use to work out generate electricity rather than using it?"
] | [
false
] | I know that some machines, like treadmills, definitely need electricity to work but for things like weight-lifting machines, ellipticals, or stationary bikes, can't they be set up so that when you pedal or lift, you are converting the mechanical energy into stored electricity? My only guess is that the energy spent lif... | [
"Most elliptical machines and stationary bikes I've seen in gyms ",
" powered by the person using them. That's why the display and electronics don't do anything until after you start using the machine.",
"Apparently some gyms, typically in academic settings, try to reclaim more energy than that and use it for l... | [
"Treadmills ",
" power, probably at least 500 watts of it.",
"Recovering power from the ellipticals will save the university a bit of energy usage. However, 6,000 KWh in a year is nowhere near what it takes to run a gym, so making gyms into net sources of power is infeasible."
] | [
"We've got this system set up at my university's rec center, there are about 20 treadmill/elliptical machines that are hooked up to the building; \"It is estimated that the 20 machines will be used by students six to eight hours each day, generating approximately 6,000 kilowatt-hours of electricity annually\". So ... |
[
"If a star is brighter than the Sun does it consume fuel more quickly or more slowly? If a star is more massive than the Sun does it have greater or lesser fuel reserves than the Sun?"
] | [
false
] | [deleted] | [
"Brighter stars are putting out more energy and thus consume fuel faster.",
"Stars that are much, much larger than the Sun are actually quite short lived comparitively. The Sun's lifespan is about ten billion years. Supernova candidates are expected to have lifespans around one quarter of one billion years.",
"... | [
"As a rule of thumb, the more massive a star is, the shorter it lives. You are right that a more massive star has far more fuel than a smaller one. But it also consume it at a far greater rate.",
"The most massive and luminous stars might live only for a few hundreds of million years, which is really short if you... | [
"The luminosity of stars is approximately proportional to their mass to the 3.5 power, so stars that are larger last a much smaller time than the Sun, and stars that are smaller last less time. Assuming that the fuel is proportional to mass, this means the lifetime t is given approximately by t=10",
" years (M/Ms... |
[
"While the launch of Space Shuttle Atlantis this gas was released from bottom of the exhaust, what is it exactly?"
] | [
false
] | [deleted] | [
"Actually this is oxygen being released from the system. The hydrogen boil off is piped away while the oxygen is vented at the engine.",
"Prior the launch, the sparks that fire ensure all hydrogen released in the initial start sequence is burnt off. The actual ignition comes from \"spark plugs\" in the burner, a... | [
"I disagree with this. Everything I've read about the oxygen bleed valve at the engine says that it is operated only after engines are shut down (which you claim for helium).",
"The helium purge of the main engines are started at ",
"T minus four minutes",
", right before the engine gimbal tests you see ",
... | [
"Not a cooling agent - just purging the fuel lines prior to launch with helium."
] |
[
"Geology (and some astronomy) question: Why do we find elements and compounds in veins and generally clumped together in the earth?"
] | [
false
] | Most heavier elements are formed in supernova explosions and float through space as dust until they are coalesced into planets. Does dust of the same element just generally form together and stays close together and so eventually it ends up either clumped up in a single deposit? Or do elements of the same variety have ... | [
"There are mechanisms that essentially sort them. You see this process on a normal time scale with something like Italian dressing. :)",
"The primary mechanisms are density, and melting points.",
"You have a big pool of mixed elements and compounds just swirling around. In general the denser liquids will set... | [
"First, this is a perception problem. There aren't that many lumps. Most of the heavy metals we mine are more thinly dispersed than you think. But some are in lodes, most commonly thought of - gold and silver, but also quartz, pyrite, a bunch of your gem stones. These are generally hydrothermal deposits. The ext... | [
"And we use the same idea of various behaviors at different temperature and pressure for extracting metals from ore, various products from crude oil, etc."
] |
[
"Could the changed gravity from the melting of Earth's polar ice caps affect our orbit in space?"
] | [
false
] | Now I know our planet isn't a perfect circle but makes our planet look extremely lopsided. | [
"Changing the orbit of two paired satellites is how the gravity variations are measured. As ",
"/u/icebean",
" pointed out in another thread:",
"This uses 2 satellites following an identical orbit with 1 a few hundred km behind the other. The distance between the two is closely measured using microwaves with... | [
"So gravity won't change, nor will the gravitational force of our planet.",
"You may be thinking of a few other things, though. When ancient glaciers melt, ocean levels rise, since there's more liquid water on the planet.",
"The glaciers of the last ice age caused some tectonic plates to sink a bit, over thousa... | [
"Any movements of the mass of ice becoming water are internal forces when you see Earth as a whole, so it will continue to move around the Sun at the same speed. It's implied by the conservation of momentum. Unless you have a teleport, the fact that speed doesn't change implies our orbit also won't."
] |
[
"Help with some Newton's Theory of Gravity."
] | [
false
] | I have some physics homework and there are 2 questions I can't get and I read the whole section and still don't get it. The centers of a 10kg ball and a .1kg ball are .1m apart. a. What gravitational force do they exert on each other? b. What is the ratio of this gravitational force to the gravitational force of t... | [
"What's the force from the Earth on a .1kg ball? In other words, what's the weight of a .1kg ball?"
] | [
"so just mg? 9.8m/s",
" * .1kg?"
] | [
"Yes, that's some number of Newtons right? So you can make a dimensionless ratio with that other force you have."
] |
[
"How feasible is using saltwater as an electricity conduit?"
] | [
false
] | Distilled water (just plain ol' H20) consists of a covalent compound that cannot conduct electricity. However, ionic solutions (which contain ionic compounds in water) can conduct electricity. Thus, I ask if using pipes filled with saltwater (perhaps from the ocean) instead of copper power lines is feasible. On a relat... | [
"I don't know its exact conductivity at ocean salinity, maybe someone else can chime in here.",
"Wikipedia says that the resistivity is 0.2 Ohm-meters.",
"To put this into context, consider a 100 meter long 16 AWG copper wire. It is about 1.2 mm in diameter, and fairly cheap. I can easily buy this on amazon for... | [
"It's a resistor. I don't know its exact conductivity at ocean salinity, maybe someone else can chime in here.",
"What's interesting about putting electricity through saltwater is that it's an effective way of making a cheap throttle for huge electrical currents, if you don't have any sort of electronic technolog... | [
"Thank you for pointing out my ambiguity. I shall try to make my future posts more clear. "
] |
[
"I have recently heard that astronomers have found an \"exomoon\". I am quite scientifically illiterate so what exactly is an exomoon and how could it affect us on Earth?"
] | [
false
] | null | [
"A planet in a solar system other than our own is called an exoplanet. Similarly, an exomoon is a moon in another solar system (and orbiting an exoplanet).",
"These things are so far away that they don't affect Earth at all. But the reason that the discovery is interesting is that exoplanets are already difficult... | [
"You're absolutely right that as a technical achievement in itself, it's very exciting. However, I would say that it also helps us develop models of how solar systems form and evolve. This has certainly been the case with exoplanets, where for instance we have discovered many gas giant planets much closer to their ... | [
"And because it is different, it allows us to perfect, create or invalidate models of how planetary systems form.\nWhich in turn is great for predicting where to find what. Like life. "
] |
[
"When is the pressure lowest in a pneumatic pump in chair?"
] | [
false
] | I believe they are used in office chairs for adjusting height. As you know- there is a default height of chair (H). It can be defined as height of the seat when no one is sitting on it and the lever is pressed. It can be increased or decreased. What I want to know is, is the gas in pump under maximum pressure at defaul... | [
"Considering ",
"Boyle's Law",
", which states that the pressure of a gas increases as the volume decreases (all other things being equal), I think it would be safe to say that it would be under the highest pressure when it's at it's minimum height. "
] | [
"Assuming the chair doesn't lock height (i.e. pressure is all that provides support), and constant piston area, looking at the force balance would show that the pressure isn't changing. I can't speak to the validity of those assumptions though."
] | [
"That would actually depend. It depends on the pressure of the gas being used to increase the height of the chair. ",
"The \"default\" height of the chair (when the chair is new, at least), would be when the pressure of the gas lifting the chair is in equilibrium with the weight of the chair attempting to lower i... |
[
"If speed and movement in the universe only exist relative to other objects, is there a difference between the Earth orbiting the Sun and the Sun spinning at 1 rotation per year with the Earth being stationary?"
] | [
false
] | For this though experiment let's assume the Earth is the only planet in the solar system. Would the Earth still be 'in orbit' around the Sun? In the solar system as it is, could this work for the Moon and the Earth, provided the Earth spun quickly enough? | [
"You would be in a weird reference frame in which there would be strong inertial forces, able to keep the sun revolving around the Earth. When you switch to an accelerating frame, you get new forces.",
"It's perfectly legitimate, but it's not exactly comfortable. "
] | [
"Acceleration is not relative, so you can detect that the earth is going around. (Change of the direction of speed is also acceleration)"
] | [
"In relativity you talk about \"inertial reference frames\" which means you basically pick something and say THIS is not moving and everything else is moving relative to it. In our every day lives, the ground is our frame of reference. When we talk about the solar system, usually we pick the Sun as a frame of refer... |
[
"Do Komodo Dragons have bacteria-laden spit, venom, or both?"
] | [
false
] | I'm so confused, I own multiple reference books that say different things! | [
"Like pretty much all animals, Komodo dragons have bacteria in their saliva, but evidence suggests that they don't harbor any particularly special bacteria and that there isn't a single pathogenic bacterium that is found in all Komodo dragons. Komodo dragons do have toxic components to their saliva, but the controv... | [
"Wow, thanks for the great answer!"
] | [
"This is an active area of research and the evidence is contested... so it's no wonder you are getting different signals and viewpoints."
] |
[
"Can you calculate the speed of a projectile based on the damage it caused a material (e.g rock) on impact?"
] | [
false
] | [deleted] | [
"I have worked on a high energy case of your question: impact crater analysis, in particular on the Moon. It turned out that the the biggest problem in being able to exactly pinpoint values characterizing the impactor (speed, angle of impact, etc.) was that the \"damage\" depended very much on the properties of the... | [
"Impact damage is quite a complex area of engineering, however it is understood.",
"The simple answer is YES - it is physically possible to solve for the impact velocity after looking at the damage caused by impact. But it becomes very difficult very, very fast; even for simple impacts and if cracks are formed i... | [
"How did you find the true speed?"
] |
[
"I'm stranded in the wilderness and have fire and spoiled meat, can I eat the meat and live?"
] | [
false
] | null | [
"Bacteria many times leave behind waste products as toxins that cannot be disinfected or burnt away. Botulism toxin can be destroyed through such a method of cooking (",
"https://en.wikipedia.org/wiki/Botulism",
") but there are many toxins that cannot (Staphylococcus aureus) or the destruction of the toxin wou... | [
"Although not a scientific answer to your immediate question, if you were looking to survive, I would suggest, instead of eating the rancid meat, which may or may not kill you, ration the meat to lure other animals into your immediate vicinity. With a bit of tact, or forward thinking you should be able to trap or s... | [
"Maybe not okay. Although cooking destroys the bacteria, the toxins produced by some bacteria are heat stable and may not be destroyed.",
"You might be okay, you might not.",
"edit: this might help - ",
"http://aggie-horticulture.tamu.edu/extension/poison.html"
] |
[
"Why do the half lives of unstable isotopes have this distribution?"
] | [
false
] | So, I recently plotted the distribution for the half lives of all the decays listed in a table of nulcides data file that I found online. (See my on ). I was really surprised to see that the data was distributed so nicely, with two well defined peaks. It looks like half lives are (at least to a first approximation) l... | [
"There are two main ways that nuclear ground states decay: alpha and beta. At first glance, I'd bet that those are your two peaks."
] | [
"the half life depends on the time taken to tunnel through a potential barrier",
"This is the case for decays like alpha, spontaneous fission, and nucleon/cluster emission, but beta decay has an entirely different mechanism. The beta particle and neutrino are created at the time of the decay; they don't need to t... | [
"I wonder if the data on github also includes primary decay mechanism? If so you could test that idea fairly easily. "
] |
[
"Will the moon always remain tidally locked to earth?"
] | [
false
] | I know the moon recedes from the earth at the rate of about two inches per year, so will the moon ever move far enough to where it will no longer be tidally locked to the earth? | [
"Once locked, always locked - unless something bumps into it, or the orbit is perturbed from outside.",
"In actual fact, both the Earth and the Moon will become tidally locked to each other, but the time scale is huge - tens of billions of years. Something will probably go wrong before that."
] | [
"At that point, wouldn't the moon stop receding, as it's no longer sapping energy away from the Earth-Moon system?"
] | [
"The term \"tidally locked\" means that the tidal forces on the moon due to Earth's gravity have caused the moon's rotation to slow to the point that it rotates at the same speed that it orbits, causing it to always face the same side towards Earth, not that it is locked into a permanent orbit. The answer is yes, a... |
[
"Why do toilets get a ring of black mold even though we have chlorinated water or when there is a chlorine tablet in the tank? And why does this ring only form at the water line?"
] | [
false
] | [deleted] | [
"I need to answer this question carefully. In general, this type of mold is bleach resistant and flourishes in environments that provide a low to moderate concentration of sugars. The reason the mold ring only forms at the water line is because it cannot survive in an oxygen deprived environment (under water), but ... | [
"I said \"in general\", not every case. I also made no comment about the species of yeast (or mold). Third, you are making a conclusion that I did not proffer. "
] | [
"It's mold but there is a hard water ring. Will use a pumice stone on it."
] |
[
"How could we protect ourselves in the case of a gamma-ray burst?"
] | [
false
] | In the case we detected a gamma-ray burst coming to us from the explosion of an hypernova. How much time would we have from the moment we detect it? What would be enough to protect ourselves from the massive amount of radiation? (from the particular small scale point of view and from the government point of view) | [
"Unfortunately the gamma rays, being just an electromagnetic wave, travel at the speed of light. We wouldn't detect it until they arrived and killed us.",
"Possibly at some intermediate distance, ie not too close for everyone to die not too far away for everyone to live, you might survive by being on the opposite... | [
"Yes, these things deliver radiation on a level completely unheard of from other events. It is probable that our atmosphere would provide little protection from a GRB aimed at the earth and even less protection from the UV component of such a burst (which is just as deadly).",
"This of course says nothing to the ... | [
"A gamma ray burst anywhere in our galaxy is potentially hazardous, the energy is so ridiculously high that we are only guaranteed to be safe from extra-galactic bursts. Keep in mind though that GRB's have very beamed radiation in the region of ~10 degrees, so even if one goes off in our galaxy it would only have a... |
[
"Did Pangaea affect the rotation of the earth due to an imbalance of mass?"
] | [
false
] | null | [
"The continental crust makes up about 0.3% of the total mass so any effect of imbalance would be negligible. As a point of interest the current configuration of continental crust is predominantly on one half of the planet today, take a look at Google Earth - you can actually position the planet in such a way that y... | [
"I have always wondered the same. The lopsided Pangea model is so strange to me personally, its so unbalanced. More importantly, How did the thick contintental crust form in the first place? And what happened to the 2/3rds of the earth that was just oceanic crust? All just subducted away? We have enough seafloor in... | [
"Is the difference quantifiably negligible or is this an assumption? "
] |
[
"Does the Earth Cause Land Tides on the Moon?"
] | [
false
] | I recently learned about the Moon causing land tides on Earth and was wondering/figured that the opposite would be true as well. Does the Earth cause land tides on the Moon, and if so, are they much more pronounced due to the lower gravity of the Moon? | [
"One of the main reasons for tides (both land and water) on the Earth is that the Earth rotates relative to the Moon.",
"However, the Moon does not rotate relative to the Earth, thereby keeping the same face toward the Earth. Therefore, the land tides on the Moon would be minimal (since the Moon is in a elliptic... | [
"In short, yes. ",
"A bump of about 50cm is raised",
" on the Moon by Earth's gravity."
] | [
"That is exactly what I was looking for, thank you. It is not the easiest searching 'moon' and 'tide' together in google for answers to my question."
] |
[
"What is a physical task that humans are really good at compared to other animals?"
] | [
false
] | null | [
"Throwing. A human can pick up an object with an arbitrary complex shape and hit a small target at huge ranges, often killing something large with a single projectile. There are other animals like chameleons or those fish that spit water on insects with comparable aim, but those don't have nearly the same flexibili... | [
" task? So we're not talking about symbol processing, language, things like that?",
"- We're very good long-distance runners. Wolves, caribou, and some antelope are in the same league, but few other animals.",
"- We can swim quite well for land animals. Traditional pearl and sponge divers such a... | [
"Don't Canadians fall in kph? "
] |
[
"How do cities without bodies of water/rivers nearby deal with sewage? Examples: Johannesburg, South Africa or Lodz, Poland."
] | [
false
] | null | [
"Smaller cities in the desert can run sewage through an activated sludge plant. The raw sewage runs through huge, open air chambers similar to oversized swimming pools. Multiple chambers run in series combine to form an entire plant. As the sewage runs through each chamber, air is blown through diffusers in the bo... | [
"I work in a wastewater treatment plant. This is a good representation to any treatment plant in most cities, the one I work at is one of 3 in our city and we have under a million people. It's funny, people just flush the toilet and it goes down the drain, no one stops to think just how much is involved after. "
] | [
"Jo'burg does have a river - that's where some of its sewage goes. ",
"According to the Jo'burg Water Authority, treated effluent is discharged into the Jukskei River, used to irrigate fields, or pumped to the Kelvin Power Station for use as cooling water.",
" Similarly, Lodz has plenty of waterways - 18 of the... |
[
"What is the validity of this blog post? I thought that endorphins were released... not oxy.."
] | [
false
] | null | [
"oxycontin and oxytocin are very different things."
] | [
"oxycontin is a very strong pain medication which is popular for abuse. Anyone talking about \"oxy\" is probably referring to this drug.",
"oxytocin is a hormone and what the article is about.",
"I assumed you confused the drug for the hormone when you called it \"oxy\""
] | [
"explain please? is it the same as endorphin?"
] |
[
"A fridge magnet can lift your keys up off the kitchen table. How is electromagnetism defeating the gravity of the entire earth when this happens?"
] | [
false
] | Gravity is so strong it holds entire galaxy clusters together. But you can hold in your hand a magnet that can yank a mass greater than itself away from something as massive as the earth? WTF is the deal with this proportion? | [
"Gravity is actually extremely weak. And extremely is quite an understatement in that sentence. Gravity is a factor of 10",
" weaker than the electromagnetic force.",
"That means that a small magnet can overcome the total gravity exerted by our planet, as you can see in everyday experiments with fridge magnets.... | [
"A nice idea, but doesn't hold up when considering the gravitational field from a neutron star, which is comprised of uncharged particles."
] | [
"The neutron star is a good counterexample, but also keep in mind that while electromagnetism might seem similar to gravity, they're very different in a huge number of subtle ways that would be pretty much impossible for them to be the same thing. This becomes obvious when you look at the math behind everything.",
... |
[
"How do cuckoo chicks know to remove host eggs after just hatching from their egg?"
] | [
false
] | Are there any other species that take on such tasks at 'an early age'? | [
"Another way to look at this: when the first cuckoo birds started laying their eggs in other birds' nests, the cuckoos got the survival advantage of not having to provide for their own chicks. But that advantage was somewhat impacted by the fact that their host's nests would have one more egg than they normally wou... | [
"well, this question arises a lot, for all kinds of animals. how do turtles know to crawl to the sea as fast as possible when they hatch? how do we know that we have to breathe when we're born? instinct, it's more fundamental than thinking and i don't think there's many thoughts involved, but thoughts are developed... | [
"Over great spans of time, this turns into chicks that hatch early and \"push\" the other eggs out of the nest. It's not like they're thinking about why they do this, it's just that the individuals that acted that way were more likely to reproduce.",
"If I recall my nature documentaries adequately, they instincti... |
[
"If I ran a signal of 500 THz through a wire, would I see light coming out of it?"
] | [
false
] | null | [
"Yes, it would emit some visible light. Unfortunately there is a lot of practical and theoretical reasons you can't have a 500THz signal in a wire. The simplest one is that the natural capacitance and inductance of any macroscopic wire is going to prevent frequencies like that from propagating. ",
"You can lookup... | [
"What is the difference between a 500 THz oscillating electric field (which would naturally generate an oscillating magnetic field) and light?"
] | [
"Good point. I stand corrected"
] |
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