title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Can we get proper scientific articles (not sensationalist news stories) that talk about NOAA's \"mystery sounds\", like Upsweep, Bloop, etc.?"
] | [
false
] | [deleted] | [
"here's a PDF link to the official summary of the research done using the Equatorial Pacific Ocean autonomous hydrophone array",
", as well as the ",
"abstract",
"It explains the various characteristics and origins of the sounds detected by the hydrophone array. As for the unknown sounds, very little progress... | [
"Fixed links:",
"Article",
"Abstract"
] | [
"Science doesn't speculate in the absence of data. There simply isn't enough data about Bloop and mysteries like it to do anything but make guesses. While we are waiting for more data and additional incidences, they will take a backburner for the time being."
] |
[
"If I got all my hair permanently removed with laser hair removal, what would my body do with all the protein that it would have otherwise gone into hair growth?"
] | [
false
] | null | [
"The human body doesn't exactly store proteins like it does with sugars and fats. Under most situations, an excess of protein or amino acids will result in them being excreted ",
"[Source]",
"."
] | [
"When you intake food your body breaks it down to essentially the macronutrient level. Your body can then utilize or store the new macros. Additionally there are metabolic cycles that can basically switch, say carbs, into certain amino acids (protein subunits) depending on the body's given demands, now or in the f... | [
"Cool, thanks!"
] |
[
"If the fourth dimension is time/duration, than what is a hypercube?"
] | [
false
] | null | [
"A hypercube is a cube in a space with more than three dimensions. You can define a geometry however you want independent of the actual universe."
] | [
"I dislike when people refer to time as the 'fourth dimension'. Rather, we believe the universe to have 3 spatial dimensions and one temporal one."
] | [
"Draw a point. Now draw another point. Now connect them. You've got a line.",
"Now draw another identical line. Connect them by the vertices. You've got a square.",
"Now draw another identical square. Connect them by the vertices. You've got a cube!",
"(Now it gets tricky). Draw another cube. Connect them by ... |
[
"Does a Photon Have a Set Amplitude? Does it Make Sense to Ask That Question?"
] | [
false
] | For a while now I've had a couple issues with my interpretation of light. My fundamental picture of light is a vibration in the electromagnetic field. I tend to imagine a ripple in a sheet or something similar propagating out. My main questions: Is a photon just that? A ripple in the electromagnetic field? Do different energy photons have different amplitudes as well as frequencies? When explaining light waves are we talking about the same 'ripple' in the EM filed as I take a photon to be? My confusion stemmed mainly from when I saw a gif showing a sine wave made up of little balls (photons) that was supposed to be demonstrating what light 'is' I'm not very confident in my conception of light. Anyone able to clear some stuff up would be much appreciated!! THANKS P.S When talking about QFT are the ripples in the fields that make up the particles the same thing I'm talking about ^ up there ^ or something more abstract to do with probability functions? | [
"A photon's single-particle ",
" (which might or might not be kosher, depending on how strict you wanna be - see my comments ",
"here",
" ) has a set amplitude, which would correspond to probability of measuring it at some point in space (in x-representation, at least). A classical EM wave amplitude (which is... | [
"Yes, I think with some difficulty you can write down a coordinate-space wavefunction for a photon, but that’s not usually how things are done in QFT."
] | [
"The “amplitude” of a single photon is not really a meaningful thing. If you have a classical light wave, consisting of many photons, the amplitude of that wave is related to the number of photons (really the average number, because a classical light wave doesn’t have a definite number of photons)."
] |
[
"If the universe is only 13.8 billion years old, but the observable universe has a diameter of 93 billion light-years, doesn't that imply that stuff at some point traveled faster than the speed of light? What am I missing? :("
] | [
false
] | null | [
"This is the first question in the Astronomy FAQ. "
] | [
"I see why you say that, but the \"soccer ball\" analogy in the FAQ doesn't explain how the distance between two points could be more than double the age of the universe in light-years. I should have done a better job wording my question... Basically, if two objects move in opposite directions at the speed of light... | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScience",
"To check for previous similar posts, please use the subreddit search on the right, or Google site:reddit.com",
"/r/askscience",
" ",
"Also consider looking at ",
"our FAQ",
... |
[
"What are the real world obstacles to tackling megafauna extinction through poaching by genetically modifying elephants/rhinos not to produce ivory?"
] | [
false
] | Is it doable technically? How might a herd adapt, or would they? | [
"I remember reading about a national park or some such in Africa where they removed the horns from some rhinos (or possibly de-tusked elephants) manually in an attempt to hinder poaching.",
"The poachers, presumably pissed off after spending a long time tracking down a rhino only to find it had no horn, shot and ... | [
"I've heard some talk about elephants' tusks getting shorter over time due to poaching. The elephants with the biggest tusks have been targeted for the past 200 years pretty heavily so as time goes on they're being selectively bred to have smaller tusks.",
"Here's one site that talks about it:",
"http://www.en... | [
"Oh man, that makes me so angry...! But thanks very much for the reply :)"
] |
[
"Is homosexuality a mental illness?"
] | [
false
] | null | [
"No."
] | [
"what do you believe are the reasons?"
] | [
"The DSM defines a mental illness as something that impairs function (see ",
"here",
"). That does not describe sexual orientation. "
] |
[
"If the Pfizer and Moderna vaccines are essentially the same, why do they have different waits between 1st & 2nd doses? And why is the age limit different for the two?"
] | [
false
] | null | [
"With vaccine prime/boost regimens, either a 3 or a 4 week interval is common and the extra week makes little or no difference. The goal is to give a long enough period for the first immune response to go to completion and start to contract, which takes around 2 weeks plus. After that, you have a window of a few we... | [
"As I said, there’s no difference. 21 days and 28 days are the same, for all purposes here. It has nothing to do with the immune response. It’s a checkbox on a clipboard when planning the clinical trial."
] | [
"Thank you for your time! Do you happen to know why the period of time required for the first immune response to go to completion is different in the case of these two vaccines specifically? I guess what I’m asking is, if they’re fighting the same virus, and are both using the same process, what specifically would ... |
[
"If I had a tube that stretched from the surface of the Earth into space would the vacuum of space pull air out of the atmosphere?"
] | [
false
] | [deleted] | [
"There would be a negative pressure from the vacuum, but also a positive pressure as a result of the Earth's gravity. Nothing would happen, thankfully, otherwise our atmosphere would leave us together. ",
"As a side note, our atmosphere is being lost to space at a small rate."
] | [
"Fun fact: a perfect vacuum will only be able to lift water about 34 ft, under atmospheric pressure\n",
"http://en.wikipedia.org/wiki/Atmospheric_pressure"
] | [
"Examine the Earth as it is right now. The atmosphere is already exposed to the vacuum of space, but gravity pulls the air together and keeps (most of) it in place."
] |
[
"Why do I remember my dreams clearest when I first wake up, but I gradually forget them during the day?"
] | [
false
] | null | [
"This may be connected with ",
"state dependent memory",
". I don't see anything about sleep-state studies in those articles though."
] | [
"You also forget your dreams while you sleep. During the night you may go through five or more sleep cycles including a dream sequence. When you wake up, you can only remember your most recent dream. If you do not write it down or rehearse it a few times, you'll forget that one too just as if you were asleep. If yo... | [
"Thanks.",
"As a followup, do you know why we forget dreams so easily? What confuses me is that I can remember my dreams quite clearly when I wake then later in the day it will be completely gone. If it was something else, for example if I was thinking about a list of things I could do as I woke up, if I tried to... |
[
"Why do we sneeze, get a runny nose and eyes, and a sore throat when we are ill? What is going on inside? And why do the symptoms seem to appear immediately and them disappear only gradually?"
] | [
false
] | Could you explain in simple terms what's going on inside to make these things happen? And if there are any legitimate ways of feeling better while your body fights whatever you have? Also, why does resting help? | [
"Sneezing, coughing and a running nose are all the response of the immune system with the intent of mechanically removing pathogens. By violently expelling infected mucous, the body reduces the amount of pathogens it must fight. \nUnfortunately for us many viruses and bacteria evolved to use this as a method of tra... | [
"So in essence, when we have a cold, do we want to sneeze and cough as much as possible to enhance your body performance to fighting it off?"
] | [
"Sneezing and coughing are the body's response to irritants; an attempt to physically expel offending objects or particles or, yes, bacteria/viruses. Coughing especially is a great way to clear clumps of infected mucus/debris and we totally encourage clearance in most of our patients, especially really sick ones!"... |
[
"If an intelligent species evolves somewhere, odds are it will be... what ?"
] | [
false
] | I'm not sure if there is any way of making even an educated guess here, but say there's a planet which isn't fundamentally different from ours, and an intelligent species evolves. Is it possible for it to be, say, an insect, or reptile, or something microscopic ? Or are mammals superior in some way ? | [
"We couldn't even fathom what it may be. It may transcend everything we can currently classify. Everything we call life is based off of our models here on earth, a sentient being from somewhere else may not fit our descriptions at all.",
"Sorry this doesn't answer your question."
] | [
"Agreed. They may not even have heads, abdomen and legs like most living things on earth do. The reason mammals, birds, reptiles, and amphibians these things is because of a group of highly conserved genes that generate body segments (called hox genes) that we got from our shared ancestor. There's no reason that li... | [
"It's too bad that this question is being downvoted, because it's actually a fun question.",
"Consider just one aspect of your life that is incredibly important to your perception of ",
": the amount of time that you spend consciously alive.",
"Imagine what would be different if you only lived for one day. O... |
[
"When a jet breaks the sound barrier, is it silent in the cockpit?"
] | [
false
] | [deleted] | [
"Not 100% sure, I'm not a pilot",
"Please avoid speculation. If you are unsure about something, find citations/sources that back up your assertion rather than saying it anyway, since it may be incorrect."
] | [
"Not 100% sure, I'm not a pilot",
"Please avoid speculation. If you are unsure about something, find citations/sources that back up your assertion rather than saying it anyway, since it may be incorrect."
] | [
"Apparently not. See ",
"this",
", by a supersonic pilot."
] |
[
"How does patient zero happen for the cold or flu virus?"
] | [
false
] | Is it just a handful of viruses that keeps moving and mutating? Or is does it start with something like a patient zero early in the season? | [
"A lot of these things start in an animal population and then that somehow infects a person. That’s a rare event. That is patient zero. But it may not be recognized unless that person infects another person. That’s an even rarer event."
] | [
"Unlikely, because they also have animal reservoirs."
] | [
"The flu also circulates in birds and pigs (mainly). Bird flu can not infect humans (generally speaking) but pigs can be infected by both bird and human/mammalian flu. This allows the different strains to mix, producing a bird flu that can infect human (putting it simply). That pig passes it on to a human and ther... |
[
"What determines whether or not a soda/pop/coke has caffeine, when they're all essentially carbonated water, HFCS, and flavorings? Do they add it? And if yes, where do they get it from?"
] | [
false
] | null | [
"In nature caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants",
"For most beverages it comes with the flavorings, like in some types of cola (and other similarly flavoured beverages) the caffeine as well as the taste derive from the ",
"kola nut",
". Other sources of caffei... | [
"Caffeine can be produced synthetically but as it's available as a byproduct of decaffeination (e.g. decaf coffee) it does not have to be.",
"Just to add to that: Every reaction step in an organic synthesis tends to require one or more purification steps, since virtually all organic reactions will result in one o... | [
"It's an added ingredient. It is possible to synthesise chemically, but it is usually easier and cheaper to decaffeinate tea leaves or coffee beans, and get the caffeine that way"
] |
[
"Since moons can be larger than planets, have magnetospheres, tectonic activity, and substantial atmospheres (e.g. certain moons in our own solar system), is there any reason not to consider moons in our hunt for habitable 'planets'?"
] | [
false
] | It seems like they can quack like planets but nonetheless get sort of written off when thinking about places where life could flourish or even places humans could colonize in the distant future. Should programs like Kepler consider moons too? | [
"No one is writing off moons, it's just that they're ",
" harder to detect.",
"Of the two most common ways to detect planets, radial velocity will only tell you the total mass of the planet/moon system, which we just assume to be essentially entirely due to the planet. It's just about impossible to tell via RV ... | [
"Regarding the potential frequency of exomoons, it's important to keep in mind is that here in the Sol system, we have between 8 and ~15 data points from which to extrapolate, rather than the one data point we had regarding exoplanets prior to the advent of 51 Pegasi and the RV technique. Based on this, I don't th... | [
"If the planet had a magnetosphere could that protect its moons from cosmic and solar radiation? Or can non-rocky planets not have magnetosphere because the pressure on the core is too high for circulating liquid iron?"
] |
[
"How do blood tests actually happen?"
] | [
false
] | Hi! I'm curious as to what are the processes involved in running a blood test, as in what is done with the extracted blood to determine the levels of a certain parameter. Why do they actually take so long? Thanks in advance | [
"There are machines and things that they use. For many tests, we have to separate the serum. This involves putting the tube in a centrifuge and spinning it down. We use a serum separator tube for collecting these samples, so it ends up that the red blood cells are on the bottom, separated from the serum by the gel ... | [
"To go more in depth, for troponin there's a very popular analyzer that uses immunochemistry. Basically, antibodies against troponin are added to the patient's serum. These antibodies have a tag so we can find them later. Then magnetic beads are added, which the antibodies attach to (streptavidin-biotin interaction... | [
"Blood test times vary depending on what test is ordered.\nLike the previous commenter said, Troponin is one of these tests. On a chemistry analyzer, it takes around 15 minutes at the fastest so long as the test was ordered STAT, which Troponin usually is. It also depends on the facility running the test. If the Tr... |
[
"What is the law for the amount of momentum transferred in a collision of two elementary particles ?"
] | [
false
] | Is there a law for the probability of transferring some amount of momentum between two ( lets say ) electrons, given some initial conditions ? Do they simply switch momenta or ( what i think ) is it random, depending on e.g. the angle ? What is the law ? | [
"Conservation of energy and momentum."
] | [
"Thank you for your answer. \nCan you give an example? Like the distribution of outcomes for a specific, simple case or, if ist possible, a formula for the distribution of a more general case, where the type of particles is fixed ( e.g. electrons ) but the initial and final positions and energies are variable in so... | [
"Thank you for your answer. \nCan you give an example? Like the distribution of outcomes for a specific, simple case or, if ist possible, a formula for the distribution of a more general case, where the type of particles is fixed ( e.g. electrons ) but the initial and final positions and energies are variable in so... |
[
"Why do some metals rust and some dont?"
] | [
false
] | null | [
"A better scientific term for metals that don't oxidize easily is ",
"noble metals",
". ",
" refers to their economic value, which is highly correlated with their resistance to oxidation, but not strictly linked."
] | [
"All metals except precious metals will oxidize when exposed to electrolyte and oxygen. If you are referring to stuff like stainless steel, it has chromium in it which reacts with atmospheric oxygen, forming a protective layer that protects the steel."
] | [
"Only iron and its alloys rust. Rust is specifically iron oxide, a compound formed when iron and oxygen combine chemically.",
"Stainless steel doesn't rust quickly because the alloying elements form a protective oxide layer that is chemically inert and greatly reduces the ability of the iron to mix with oxygen.",... |
[
"How do we know that Lucy is a direct human ancestor?"
] | [
false
] | Hey - fairly simple question I'm having trouble googling. How do we know that Lucy is a direct human ancestor and not just some other random ape/hominid? Besides the fact that her body fits our theories for a transition from ape to human, is there some other kind of evidence that proves Lucy is a part of our ancestry and not some random offshoot of another ape line? (If that makes sense). | [
"In a sense, we don't. There's nothing dictating that Lucy was a great-great-great-[...]-grandparent of the common ancestor of humans, since it's basically impossible for us to map out a complete individual-level family tree through the fossil record. This is the pitfall of the \"linear\" model of evolutionary thin... | [
"Got it - I was mainly curious if there was some evidence besides the similar skeletal structure, etc. Not sure what it would've been but thanks for answering!"
] | [
"Got it - I was mainly curious if there was some evidence besides the similar skeletal structure, etc. Not sure what it would've been but thanks for answering!"
] |
[
"When we say an atom is stable as it has achieved an octet electronic configuration,what do we exactly mean by stable?"
] | [
false
] | null | [
"An atom is stable if it has a full set of electrons. How many is a full set? 2(N",
" ) where N is the row on the periodic table. When you do the mathematics to solve the hydrogen atom, you find that electrons will distribute themselves into energy levels. The problem is, we can really only solve the hydrogen... | [
"Stability is in comparison to the reactants that make it up. For example, the ions of Na+ and Cl- in NaCl are more stable than their corresponding atoms Na and Cl in Cl2. This is because with the electron transfer from Na to Cl, both have a full outer electron shell. ",
"A compound where all the atoms have a ful... | [
"Oh wow! Thank you so much for taking the time to answer my question! I genuinely appreciate it alot! Cheers buddy!!! :)"
] |
[
"How do biologists estimate the population of endangered species?"
] | [
false
] | Bonus points for explaining how they estimate marine populations, given how large in every dimension our oceans are. (An article I just read quoted a specialist saying there are "roughly 468 Right Whales" remaining. How do you arrive at such a specific number with confidence?) | [
"There are various techniques; which one is most relevant will boil down to the species. Mostly it boils down to estimating the density of that species, then multiplying it by the area of suitable habitat.",
"Densities can be estimated by methods such as transects - walk (or drive) a path, counting any individual... | [
"Thank you for the in-depth response! I have no follow-up because that pretty much covered everything."
] | [
"Another way to estimate a population is by using a technique called ",
". In this method, you sample the population multiple times. Each time, you record the number of individuals you've captured and then mark them in some way (e.g. banding the foot of a bird, clipping the pelvic fin of a fish). From the second ... |
[
"Would gravitational lensing allow for an infinite number of stars and not result in a white sky?"
] | [
false
] | If gravitational lensing causes light to become scattered, than it seems that the light that is farther out will have a greater chance of being diverted before reaching us so that we can detect it. I am not asking whether or not that light exists in the first place, I am asking if my thinking is correct or if there are potential problems with my hypothesis. Also, is there a better subreddit for asking scientifically speculative questions such as this? | [
"This is pretty much the subreddit for scientifically speculative questions. And no, gravitational lensing would not solve Olbers' Paradox, since the light still has to go somewhere (same total amount of light in the universe, regardless of whether/how it's lensed). Also, gravitational lenses actually magnify the o... | [
"If a celestial body absorbs light, it's going to re-radiate it (generally at a longer wavelength). But that's completely and utterly unrelated to gravitational lensing. Lensing does not destroy or create light, just redirects it, and there is no possible way for the total effect of gravitational lensing to be a de... | [
"My reasoning behind it is that there may be enough celestial bodies to absorb a large portion of light over those log distances, along with the scattering due to gravitational effects, that light has a much lower chance of reaching over super long distances.",
"I would like to give an example. If you have ever ... |
[
"What exactly are polynomials used for?"
] | [
false
] | So I have been learning about polynomials in school for the past couple of weeks (graphing them) and our teacher told us that we won't need to actually use them later in life. So what exactly are they used for? Edit: thankyou guys so much. You have taught me almost more than what school has taught me about this. Thankyou :) | [
"our teacher told us that we won't need to actually use them later in life.",
"Ugh. What a shitty thing for a teacher to say. I also know the pain of having had horrible K-12 teachers.",
"It's probably true that most people in your class will \"never need to use them later in life\", but that's true of a lot of... | [
"In addition to all the very important practical things mentioned by ",
"/u/Overunderrated",
" , polynomials are also very fun. It's okay to learn things for the sake of learning, without considering any practical concerns. A sign of a highly cultured society is the opportunities for it's citizens to learn with... | [
"The thing that I think everyone is glossing over is the following:",
"A function is any \"box\" which takes in an input and spits out a unique output. A box which takes in teacups and spits out their primary color is a function from the set of teacups to the set of colors. ",
"Most functions you study in mat... |
[
"Can wasps/flies detect the difference between real sugar and aspartame?"
] | [
false
] | If so, do they selectively prefer the real stuff? Struck me that insects that go after sweet liquids might be able to tell the real from the fake - if they can, any insight into the mechanism by which this occurs would be greatly appreciated. | [
"They will be attracted to it but because they can't be metabolized which means they provide no sustenance to the bug.",
"This is the same reason hummingbird feeders explicitly say not to use artificial sweeteners- the birds will eat it, get 0 calories, and starve to death with a full belly. "
] | [
"what's the sensory component here? do they \"smell\" sweet in the same way we do? "
] | [
"Not as different as one may think. There are plenty of examples of various genes that are conserved between vertebrates and insects. ",
"However... ",
"you seem to be correct about the divergence of chemoreceptors.",
" (ps sorry about the paywall if you are not going through a university library system)",
... |
[
"Would extreme time dilation make it possible to travel to a distant galaxy in one human lifetime (from the traveler's perspective), assuming you were going fast enough?"
] | [
false
] | I remember reading about this idea in in a book awhile ago, but was wondering if it had any credence. | [
"That page also mentions another show-stopping problem with fuel, if you plan to slow down by the time you reach the other galaxy, rather than zipping through it at near the speed of light. ",
"Their calculation for reaching Andromeda requires 4.2 billion tonnes of fuel for each kilogram of payload, and that's a... | [
"See the ",
"relativistic rocket",
". They show how much time and fuel needed to go anywhere in the universe at a constant acceleration g. You could go to Andromeda (2Mly away) in 28 years."
] | [
"Yes, you can go what a appears (in the earth's frame of refence) to be an arbitrarily long distance in what feels like (in your frame of reference) an arbitrarily short amount of time.",
"However, from the perspective of the earth, the trip will still take you (distance)*(speed of light) + a little bit of time. ... |
[
"If I am trapped at sea, to what extent can I extend my Freshwater supply by mixing it with seawater?"
] | [
false
] | To the extent of my knowledge, Medical saline is something like 0.9% NaCl and human fluids are isotonic at somewhere around 0.6% Most seawater appears to be in the 3.5%-4.0% range. What is the "safe" ratio that I can mix seawater with my freshwater supply without suffering from excessive salinity? | [
"I did some math, and I came up with 1:9, which is Salt water to Fresh water. \nThe ratio of 1:9 would be tolerable for a human to survive out at sea. Therefore, if you mixed 1 Liter/Gallon/etc, with 9 liters/gallons/etc, you would have 10 of the units specified above to drink. ",
"Work: \nHumans can tolerate 800... | [
"The concentration of medical saline was chosen to be isotonic with the body, so that's the highest concentration of fluid you can consume without losing water. Some simple math shows a concentration of 25% seawater, or one part of seawater to 3 parts of freshwater.",
"If you're actually stuck at sea, you might ... | [
"I made a comment showing your numbers but with extremes. For best physical condition 1:9 should be done (Salt to fresh), and to have the extreme minimal it would be 1:0.5. Work shown above. The average would be around 1:4.5 which is spot on with your calculations. "
] |
[
"Why is recommended that humans eat a varied diet while pets generally do fine with the same meal every day?"
] | [
false
] | null | [
"Pet food is specially formulated to give the pet all the nutrients it needs. There are also owner-comfort considerations involved - such as making food that results in a more solid stool because pet owners don't like mopping up diarrhea. ",
"The reason we're encouraged to eat a balanced diet is because we don't ... | [
"General Mills is one of the companies that worked on the development of the MannaPacks. The concern for food aid to people who are literally starving is getting them nutrition. Flavor takes a distant back seat to just getting the food in them, and keeping it in them. These are kids who sometimes haven't eaten in a... | [
"That's very interesting! I'm surprised there hasn't been much interest in making something like this more palatable, especially if you remove the cost aspect or the punishment aspect. I would that if General Mills or Kelloggs took up the project, they could figure out how to add enough sweetener and artificial fla... |
[
"What happens to DNA after it is split in half (parts of it at least) during RNA transcription?"
] | [
false
] | Do the hydrogen bonds reform? Does it just become useless from then on? Does it matter if they stay separate? | [
"It comes back together. When DNA is being transcribed it typically does not involve the entire genome at one time, so pieces of the DNA will open up for the gene that need to be expressed at that time while other locations stay stuck together. When the gene is done being transcribed, the strands can link back toge... | [
"Just want to add that the area that's \"open\" is called the transcription bubble. "
] | [
"In short the hydrogen bonds reform.",
"first a good model is PCR to answer this question I think, in which pieces of double stranded DNA are used. In PCR we replicate DNA by first separating through heating, we then lower the temperature enough to allow a primer to associate and bond with the single strands and... |
[
"Emission lines of elements. Why the trend?"
] | [
false
] | I'm looking at the emission lines of elements on the periodic table. It is obvious that heavier elements emit K-alpha and K-beta rays of higher energies. Why is this so? I'm guessing it's something to do with the electrostatic charges between the nucleus and electrons to be greater in heavier elements? | [
"Yes. If you look at hydrogen-like atoms (a single electron) then all energies scale with the squared charge of the nucleus. For the innermost orbitals this is a good approximation to the energy even with more than one electron. For the other orbitals this approximation gets worse, but not enough to change the gene... | [
"Moseley's law, for those who want to look it up."
] | [
"👍 thanks!!"
] |
[
"What happens when two black holes collide/combine?"
] | [
false
] | This was asked in shittyaskscience, but I'm genuinely interested. Anything more interesting than just "a really big black hole"? | [
"http://www.youtube.com/watch?v=mHwHM5KjSVE"
] | [
"Almost a FAQ here.",
"One interesting thing is that \"the resulting black hole can have a \"kick\" imparted to it, possibly on the order of 1000s of km/s.\".",
"One person thought to study black holes professionally suggested that depending on something (spin? charge?) they might result in an infinite number o... | [
"Brilliant, thanks!"
] |
[
"Does 'padding' a file before encryption, by artificially increasing its size, it make it more secure against cracking?"
] | [
false
] | I wasn't sure if this was more of a computing or math question. But, for example, say I have 'secretfile.txt' and I want to encrypt it. Say it's 5kb in size and I want to encrypt it with AES using GPG or whathaveyou. But, before I encrypt the file, I create a 50MB file of zeroed data, call it zero.bin, and then tar both 'secretfile.txt' and 'zero.bin' together. I then encrypt the tared file, resulting in a ~50MB encrypted file. Would this offer any extra protection against cracking than if I was to just encrypt the 5kb file by itself? In other words, does the size of the original data matter when it comes to the strength of the encryption? If it's not applicable to AES, are their other ciphers besides AES that this would be true? | [
"No. The mathematical requirement for a block cipher to be considered secure is that all plaintexts will result in ciphertexts that are indistinguishable (by a computationally bound attacker). To any attacker, there would be no statistical way of being able to distinguish a file that was 50.5 megabytes worth of ran... | [
"Would it further increase security if you could add random data to the plaintext which a human being could know to ignore, but the machine would encrypt as though it's meaningful?"
] | [
"In short, yes and no. Yes, padding can increase the security; No, adding 0's to a 5KB file to make a 50MB file doesn't increase the security. ",
"For a basic analogy, think about the last time you played hangman. Whether or not you realize it, you definitely use number of letters in the word to help you make... |
[
"How can the atmosphere of planets create false positives for life?"
] | [
false
] | I saw it mentioned in twitter, and was wondering how that worked. | [
"The point being made in that tweet is that unless we have some kind of monumental event like a signal from or encounter with extraterrestrial life, what we're looking for will be pretty hard to confirm as a definite sign of life.",
"So we can, for example, analyze the composition of the atmosphere of exoplanets ... | [
"There are other processes that can create oxygen gas, so it'd be an exciting, but still not totally conclusive find. The same goes for many organic gasses."
] | [
"Thanks for the detailed answer :)"
] |
[
"Considering that the earth is a few billion years old, how are elements with a half-life of a few million years naturally found?"
] | [
false
] | Logically wouldn't they all decay down to their most stable forms considering how long the planet has been around since most of them were created in the early solar system? | [
"Short lived (compared to the age of the Earth / Solar System), naturally occurring radioactive isotopes are produced in a few different ways. Some occur as part of decay chains, e.g. ",
"U (245,000 year half life) and ",
"Th (75,000 year half life) occur as part of the ",
"U decay chain on its way to ",
"P... | [
"It wasn't. This is the reason why we have to calibrate our dating methods, e.g. with dendrochronology. ",
"Edit: I am currently in a lecture, so please excuse my short answer."
] | [
"A young-earth creationist was trying to debunk the 14C radiometric by affirming that the production of new 14C was not uniform, so the calculus is wrong.",
"As others mentioned the variations are both well-known (so the argument fails completely) and small (even if they wouldn't be considered they would still ru... |
[
"Why does water start bubbling before boiling point?"
] | [
false
] | Is 100C just an average boiling point? Or are there some molecules (sorry if I've used the wrong description) that already have a higher amount of energy than others and so boil sooner? If so, what's the minimum boiling point for each individual molecule? | [
"Adding to the other answers that have mentioned non-homogenous heating: the bubbles come from the dissolved gasses in water. Dissolved gasses are less soluble in hot water, so they \"bubbles out\" at elevated temperature. ",
"The solubility is not linear, however, and has a noticeable drop near 80",
" C. Ar... | [
"Fun fact about the Leidenfrost effect: It works on a basis of temperature DIFFERENTIAL, rather than just our perception of \"hot and cold\", such that our hand is blazing hot to a droplet of liquid nitrogen. So, you can skid beads of LN2 on the palm of your hand with no ill effects in the exact same way water dro... | [
"Fun fact about the Leidenfrost effect: It works on a basis of temperature DIFFERENTIAL, rather than just our perception of \"hot and cold\", such that our hand is blazing hot to a droplet of liquid nitrogen. So, you can skid beads of LN2 on the palm of your hand with no ill effects in the exact same way water dro... |
[
"Are there any molecules that are connected mechanically? (like two links in a chain)"
] | [
false
] | If so, do these have any special properties? Can they be used to create nano-scale machines? | [
"Yes there are. They are called ",
"catenanes",
". I read one paper where they used loops of DNA to build up networks of nanoparticles."
] | [
"That sounds pretty neat! Are they able to rotate around each other, or are they pretty much locked in place?"
] | [
"You might be able to design small molecule catenanes (like the ones on the wiki page) that wiggle a bit but van der waals and electrostatic interactions usually lock things down pretty well. However, larger polymers like DNA can form knots, plectonemes, and catenanes that are very dynamic. ",
"This paper",
" s... |
[
"Would it be possible to harvest stem cells?"
] | [
false
] | So, from what I've read... Stem cells are used in cloning, repair, etc. because they have the ability to transform into any specific type of cell. I've also read that before the cells change they continue to reproduce and won't die off. Taking this into account, would it be possible for someone to harvest stem cells? | [
"It depends on what type of stem cell. A process that is done almost routinely nowadays is harvesting of \"bone marrow stem cells\" and then transplanting them into a patient with leukemia (cancer of the blood). These bone marrow stem cells can either be harvested directly out of the bones, I believe usually from t... | [
"Some minor corrections. The growth factor used is ",
"G-CSF",
" (granulocyte colony stimulating factor). ",
"GM-CSF",
" exists as well but it is a different factor. The harvesting is done using a process called ",
"apheresis",
"; the process looks like dialysis but it's fundamentally different."
] | [
"Thanks for correcting!"
] |
[
"Does the length of our day account for the fact that we're moving around the sun too? How about when we talk about other planets?"
] | [
false
] | [deleted] | [
"Have a look at ",
"sidereal time"
] | [
"You have it backwards. The Earth takes 23 hours 56 minutes to rotate. It takes 24 hours to return to pointing back at the sun. Think about the stars behind the sun who won't be moving relative to your viewpoint. In 23 hours 56 minutes, they'll be exactly where they were in the sky (this is why astronomers use ... | [
"You have it backwards. The Earth takes 23 hours 56 minutes to rotate. It takes 24 hours to return to pointing back at the sun. Think about the stars behind the sun who won't be moving relative to your viewpoint. In 23 hours 56 minutes, they'll be exactly where they were in the sky (this is why astronomers use ... |
[
"Does vaso-constriction or dilation aid more in uptake of a solute in the blood?"
] | [
false
] | This is one of those questions I could debate for either side, but science doesn't work that way, so here we go; vasoconstriction would mean a higher arterial wall surface area to blood flow volume ratio while dilation probably results in a higher rate of blood circulation. But, then again, vasoconstriction usually accompanies a peak in blood pressure (and vice-versa), so maybe blood flow stays nearly the same in spite of the diameter of the pipes. But then AGAIN, there are many different sized veins in the body, and we all know that cubic growth (flow) is outpaced by square-ular (couldn't think of the word) growth (surface area) for a short window probably represented in tiny skin blood vessels as opposed to the big arteries, and blood vessels make up a large part of our body's transport systems. I had this thought after taking a melatonin after smoking a cigarette (solute and vasoconstriction, respectively) and could not for the life of me reach a conclusion. That being said, it's very late at night so it's possible I don't make any sense in my reasoning anyway. There is more than likely a simple answer/explanation and thus you will collectively call me stupid. I do look forward to some closure, however. Thanks in advance, . You're one of my favorite reddits. | [
"I can't remember the case for intestinal absorption; however alveolar respiration I do remember.",
"The lung attempts to keep CO2 & O2 concentrations constant throughout the lung. One way it does this is by dilating alveolar blood vessels that are high in [CO2] to allow for more gas exchange. Thus, dilation lead... | [
"The largest factor is transit time. If the rate at which blood flows past is faster, less diffusion can occur. In the case of the lungs it's also important to note that if an area of the lung is underventilated (receiving little to no fresh air) that the vasculature there constricts in order to allow great blood... | [
"Thank you both for your in depth responses. "
] |
[
"Is there a distance from earth at which all stars are guaranteed to have expired by the time we see them in the present day?"
] | [
false
] | I was curious whether there was a constant for this earlier so I did some searching, but can't find anything on the subject. Is there any knowledge of a distance from earth at which an object in space is guaranteed to be 'dead' while being observed from here in the present day? As a side note (and somewhat along these lines), how far would an object have to be from earth for its light to have never been seen from earth up to the present day? Apologies if these questions are nonsensical, illogical, or overly simplistic. | [
"No. Red dwarfs have lifetimes on the order of hundreds of billions of years; therefore, a red dwarf which formed in the very beginning of the universe would still be shining today, and would continue to shine for many dozens of billions of years.",
" This assumes that population III low-mass stars are possible.... | [
"They very first stars may have been high-mass because they were zero-metallicity and formed in dense environments.",
"However, while massive stars were almost certainly more common, it would be surprising if there weren't at least one red dwarf from that time period."
] | [
"I just want to be sure I follow this train of thought correctly: the very first stars may have, of necessity, been high mass because concentrations of matter were all much higher than they are today?",
"If that's the case, how long would it have been before these stars \"burned out\" and low mass stars like red ... |
[
"Are there any \"good\" viruses?"
] | [
false
] | [deleted] | [
"On the question of 'good' viruses, I guess you could count most bacteriophages (see link at end) as 'good'. These are viruses that infect bacteria. During the 20th century, there have been some efforts to use phages to fight infections, initially with mixed results. They kind of fell out of the limelight once we d... | [
"HIV-derived lentiviruses are routinely used in the lab to introduce target genes to mammalian cells. For example, the creation of induced pluripotent stem (iPS) cells was performed using lentivirus. Although these types of virus are not naturally occurring, they are certainly \"good\" in the sense that they have b... | [
"Yes, there are a few examples of \"good\" viruses.",
"\"Seneca Valley-001\"",
"Vaccinia",
"latent herpesviruses can be protective against plague",
"less serious viruses can alter the course of harmful viruses.",
"theoretical possibility",
"Typhoid Mary"
] |
[
"Is it possible for organic matter to be blown off earth during an asteroid strike and land on the moon?"
] | [
false
] | I recently came across a Joe Rogan episode on why he changed his stance on the moon landing. One part of it was talking about a "moon rock" given as a gift that turned out to be petrified wood. While this instance is theft or deceit, it got me thinking about the asteroid impact that caused our last mass extinction. Was there enough force in that impact to Launch debris into space? Would the speed required to leave our atmosphere vaporize any organic matter traveling with it? I guess my main question is if a piece of wood were left on the moon for an extended period of time, what would it's aging process look like? How would it differ depending on if it were sitting on the surface or had been driven into the ground? I assume that due to less gravity nothing would be under the same amount of pressure that it is here on Earth. | [
"We have ",
"some meteorites which we believe to be of Martian derivation",
", so at least conceptually, it might be possible for a meteorite of Terrestrial derivation with some kind of signature indicating the presence of life to have been thrown out into space at some point.",
"But I'd add a couple of ",
... | [
"Earth also has stronger gravity and a thicker atmosphere, both of which will reduce the amount of material than can escape, compared to Mars."
] | [
"Life on Earth has been known to be around from very early on for quite some time. The Nuvvuagittuq critters merely represent an incremental pushing back of the earliest data known for living things; the previous holders of the title were dated at about 3.7 Ga. However ",
"carbon with isotopic signatures indicati... |
[
"If two people with the same contagious illness are confined together, is it likely that it’ll take longer for them to get better than if they were separated?"
] | [
false
] | null | [
"Not necessarily. In fact, this is called cohorting and is sometimes practiced as a way to prevent the spread of disease. For example, if you have two patients with the same antibiotic-resistant organism, sometimes they will be put in isolation in the same room. They both have the same thing, so they can't really i... | [
"While an additional infection would result in a competition for resources, since ",
" are the resource, you would be 'sicker quicker.' In contrast, the microbes on the skin have a beneficial effect because the resources they compete for are not your cells; this idea works for some situations, just not an interna... | [
"Silly idea, but can you theoretically infect someone with a non-resistant strain of the same bacteria, so it will compete with resources with the resistant organism? I know it's largely useless, because as soon as you start the antibiotics you're back where you started, but now I'm wondering if \"similar infection... |
[
"[Biology] How much control does our mind (active thoughts) have over our body?"
] | [
false
] | null | [
"Hard to answer this one, its a mix between everything and various organs. I can tell you that GI track is defiantly altered by the brain as is the hormone system. How far into this 'control,' can be described before I start talking about potential of healing? Where does the \"placebo\" capacities end and begin? ... | [
"In regards to the mind working on the body, active thinking(consciousness), I consider that a top-down method, which seems more difficult to make the body react. If we were talking about a subconsciousness, this can effect everything seemingly. But it seems the top-down method does work.\nIf I concentrate on basi... | [
"That's actually pretty cool. Thanks!"
] |
[
"Lily zombie growing in basement w/no sun, very minimal, very intermittent incandescent light and no H2O... Is this normal?"
] | [
false
] | [deleted] | [
"Bring the poor thing into the light!",
"Lilies, and many plants can have a dormant phase. It's possible that the dark cool basement triggered a 'winter', and the plant is trying to grow again. It is using the energy in the bulb to keep growing without light, but it won't last forever. It is white because it is n... | [
"You might be surprised just how much lilies will grow without any light. Easter Lilys usually have enough stored energy to make it all the way to flowering with zero light. Here's a ",
"picture",
" of an easter lily grown in complete darkness next to a normal one. "
] | [
"I'd say other way 'round. The long one attempts to grow to reach light, assuming that it's in the shade. The short one is perfectly content with the light it gets, and so produces more chloroplasts (hence its darker colour)."
] |
[
"How strong are pulsar electric fields?"
] | [
false
] | I had come across papers describing the model for which electric fields are produced from pulsars and the coherent radiation arising from such pulsars. Based on a simple analysis of I = (1/2)cε<E^2> and observed luminosities of pulsars being L ~ 10 J/s, then if I ~ L/A (where I assumed A ~ 10 m simply based on a pulsar radius of 10 km), we have E_avg ~ 10 V/m. I can't help but think my calculations here are extremely crude. But are expected pulsars really emitting electric fields of such strength? Higher (e.g. closer to the Schwinger limit) or much lower? (Please let me know of any heinous approximations I made in my calculation, such as the area of the surface in which this electric field is being produced and emitted.) | [
"The rough electric field strength can be given by RΩB/c (see ",
"here",
" or ",
"here",
" when r=R or the Handbook of Pulsar Astronomy equation 3.18). In our typically obnoxious ",
"Gaussian cgs units",
" (since there's probably some other factors that are missing), the first link describes the electri... | [
"Thank you for the response. So if were to convert this electric field to an intensity, we would get I ~ 10",
" W/m",
" But then if we're further considering a uniform field and a a neutron star's surface as the area (with radius 10",
" m which is likely quite a bit lower than the true area of the radiating r... | [
"For one, the emission is beamed so you're not supposed to take the whole surface area of the star (though you may need to move farther away and consider the magnetosphere where the emission occurs, thus changing r as well). However, the more important point is that this is the ",
"local intensity",
", i.e., de... |
[
"Human vision only focuses on a small area in the field clearly and the rest is blurry. Are there any animals that can focus on everything at once?"
] | [
false
] | null | [
"The ",
"cuttlefish eye",
" is considered one of the most developed in the animal kingdom*, and it has multiple ",
"fovea",
" as compared to our single one.",
"In general, though, the answer is no, for the reason that neural processing power is metabolically expensive, and having only as much acuity as yo... | [
"Well, no eye is considered \"the most developed\", and cuttlefish ",
"can't see color (or at least can't match it)",
".",
"I'll also add that neural processing is not the only limitation. In vertebrate eyes, the neural encoding happens in front of the photoreceptors. They then have to leave the eye through a... | [
"What evolutionary advantage is there to having our optical nerves configured in such a fashion?",
"That is a very good question, and the answer is \"None whatsoever.\"",
"Living systems are full of workarounds like this. The torturous route of the ",
"recurrent laryngeal nerve",
" in tetrapods is one of ... |
[
"[Computer Science] How does formal verification not \"solve\" the halting problem? Or does it?"
] | [
false
] | I don't understand how it's possible have a given input program, hold it to a set of rules (rules in this case being the software language/grammar), and guarantee that it will compile and run "as intended" based upon the input program spec? Wouldn't that be saying, in essence, "any valid program in <given language> is computable and doesn't go into an eternal loop"? And if you were making that guarantee, didn't you solve the halting problem? Or is the halting problem only "solved" for the subset of programs that can be written in <given language>? Or am I totally off-base in some other fashion? | [
"You are right, that question is equivalent to the halting problem.",
"But the issue with the halting problem is not that you can't decide if a ",
" program will halt; the issue is that there is no way to decide is an ",
" program will halt.",
"For some specific programs, there are specific techniques that ... | [
"The halting problem says that you can't make an algorithm that for certain can divide (turing complete) programs into terminating and not-terminating without error. What you can do is divide programs into terminating and maybe-not-terminating. In fact there is a trivial solution that simply puts every program in t... | [
"So basically you might get some acceptable level of false positives in the \"maybe-not-terminating\" category as a tradeoff to not bumping into any infinite loops? Cool!"
] |
[
"What did early man do to deal with his fingernails?"
] | [
false
] | This might be a tough one to answer, but I was clipping my fingernails recently and got to thinking: if we need to trim our nails, what the heck did pre-tool hominids do deal with their nail growth? : Thanks for the gold! | [
"Reminder: this is AskScience, so please do not post speculative answers or anecdotes. Any answers should be based on peer-reviewed science."
] | [
"This is not just a human problem. Other primates have fingernails instead of claws. ",
"Our fingernails are very similar to Chimpanzees",
". Chimpanzees treat fingernails in different ways. Some allow them to grow until they break off. Others bite them and some even use rough stones as natural fingernail f... | [
"Related - but what about toenails? After suffering through three ingrown toenails (most painful thing I've ever experienced) I wondered \"how did early man deal with this crap? ",
"Ingrown toenails seems like something that should have been Darwined out of us by now as anyone with an ingrown toenail is both eas... |
[
"How does a ship turning create a region of flat water?"
] | [
false
] | In WW2, floatplanes launched from ships were recovered by taxiing the plane in flat water created by the ship entering a turn. My question is, how does this region of flat water get created if a ship's wake is supposed to be turbulent? example: | [
"Turbulence and smoothness of water are not mutually exclusive. Turbulence is ",
" the same thing as chaotic surface waves. Turbulence actually ",
" the amount of surface waves that can transmit through a region of water. Unfortunately, I don't have any more information than that, but hopefully it covers your q... | [
"When a ship travels forwards, the keel slices through the water, and the water flows past easily.",
"In a turn, the keel pushes against the water amd causes it to create rolling turbulence. As the above comment explains, the turbulence of the turn prevents eaves from travelling over the area. The plane will then... | [
"Sorry for late reply, but thanks."
] |
[
"How was Avogadro's number derived?"
] | [
false
] | We know that there is 6.02x10 atoms in 12 grams of carbon-12, but how was this number came up from? | [
"Someone gave a good response that quoted from Wikipedia, but I'd like to share how Avogadro's constant (N_0) came about.",
"",
"Avogadro coined this idea in 1811, when he first proposed that the volume of a gas is somehow proportional to the number of atoms/molecules in the gas.",
"Jean Perrin defined it as... | [
"Because mass was always defined against a platinum-iridium ingot kept in France and that changed mass a couple times over the centuries so they had to stop doing that."
] | [
"Because mass was always defined against a platinum-iridium ingot kept in France and that changed mass a couple times over the centuries so they had to stop doing that."
] |
[
"Why doesn't every chess game that Google's AI alpha zero plays against itself end up in a stalemate?"
] | [
false
] | From what I've heard Google's AI alpha zero has a training period, where it plays against itself to become better.At those games specifically how come that even though its opponent has the same knowledge and same resources the game doesn't always end up in a stalemate? Thanks in advance! | [
"Chess isn't an easy game to force a stalemate with. While it can be done easily ",
" when you are trying to do so, most competitive stalemates occur when one player is fighting hard against a loss and forces it.",
"Because Alpha Zero is playing millions of games, memorizing the outcomes, and moving on, it does... | [
"Because the game isn't symmetrical.",
"We can prove that one of the players can either always win or at worst force a draw against the other.",
"We don't know which one but it's wildy believed to be white and experiments support it."
] | [
"You can think of a learning algorithm as having a massive set of dials that control its behaviour, which is governed by its architecture. When it's learning, it randomly tunes the dials and sees whether this moves its behaviour in the desired direction or not. When it's playing itself the dials are set to differen... |
[
"What are the base pairing rules for DNA, what is it that makes bases pair? And how does this carry over to DNA to mRNA and tRNA?"
] | [
false
] | null | [
"Adenine (A) can pair up with uracil (U) or thymine (T). Guanine (G) pairs up with cytosione (C).",
"You find U in RNA, T in DNA, they carry the same information, and the pairs work the same way.",
"It's hydrogen bonding, like what you get in water. ",
"Because of the way the molecules are shaped, G has three... | [
"For DNA, it's always adenine (A) with thymine (T) and guanine (G) with cytosine (C). When DNA is transcribed to RNA, the only difference is that thymine is replaced with uracil (U) so it's A-U, G-C.",
"Adenine and guanine are classified as purines because of their double ringed structure while cytosine, thymine,... | [
"You're forgetting about wobble pairs and modified/irregular bases.\nG-U is a very common pairing for tRNA and mRNA.\nInosine (I) is a common base in tRNA."
] |
[
"What exactly happens in fission and fusion reactions? and how are fission chain reactions sustained?"
] | [
false
] | [deleted] | [
"Neutron irradiation is one convenient way to induce fission reactions on heavy targets. This is what is used in fission reactors and bombs.",
"In a thermal neutron induced fission reaction, the heavy target nucleus (something like uranium-235 or plutonium-239) captures a thermal (meaning relatively slowly-moving... | [
"Fission involves a nucleus splitting into two or more \"heavy\" fragments (heavy typically meaning nuclides with mass numbers higher than an alpha particle).",
"Fusion reactions are compound nuclear reactions where two reactants come together and form a heavier system, possibly losing a few particles in the proc... | [
"Thanks for the reply, but regarding fission, how is an atom split? I've read something that says it's to do with being hit with neutrons, is this true? Is there a more scientific explanation?(most probably) "
] |
[
"Would it be possible to charge a phone battery faster if lifespan of the battery wasn't accounted for?"
] | [
false
] | null | [
"Reply to the above ",
"/u/AskScienceModerator",
" comment with any of the following (without quotes):",
"'Computing', 'Economics', 'Human Body', 'Engineering', 'Planetary Sci.', 'Archaeology', 'Neuroscience', 'Biology', 'Chemistry', 'Medicine', 'Linguistics', 'Mathematics', 'Astronomy', 'Psychology', 'Paleon... | [
"Hi saturatedmorning 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 th... | [
"How do I add flair? I'm on mobile."
] |
[
"Why doesn't the use of constants with dimensions invalidate dimensional analysis?"
] | [
false
] | For example, in Newton's law of gravitation, we have F = (GmM)/r which gives the dimensions of Newton's gravitational constant as L /(MT ). If we choose constants to have certain dimensions so that our equations balance, then what use is dimensional analysis in validating these relationships? Or does the fact that we have to introduce such constants simply indicate a lack of deeper understanding of the situation? Are the equations governing more advanced theories like General Relativity dimensionally consistent while only using dimensionless constants? | [
"From a fundamental perspective you're right, and in practice some branches of physics like high-energy physics use systems of ",
"natural units",
", in which distance, time, and mass are all converted into one common unit using factors of the speed of light c, plank's constant h, and the gravitational constant... | [
"Basically I'm saying \"its usefulness is limited\" and providing you some related information.",
"I know G isn't going to show up in a spring calculation because springs are a non-gravitational phenomenon. As one does a lot of calculations, they learn when various constants might appear. It's a handy tool for ... | [
"If we make an equation like F=x, that doesn't tell you much of anything by itself. But then, through experimentation with gravity, we determine that F decreases by the square of the distance. Ok, now we say that F=x/r",
" What is x though? Well, we could stop there, but then we would realize that it doesn't let ... |
[
"How did people keep their teeth from falling out before modern oral hygiene practices?"
] | [
false
] | Nowadays, it's pretty common for people to see a dentist twice a year for a cleaning/checkup. Before modern dental practices (let alone toothpaste), how did people manage to keep their teeth from rotting out during the span of their life? Thanks for the help! | [
"Additionally, their diets had significantly less sugar and acids than modern processed foods do."
] | [
"Additionally, their diets had significantly less sugar and acids than modern processed foods do."
] | [
"Basically they didn't need to before we started adding sugar to stuff. People's teeth were mostly fine dealing with normal foods.",
"The period between the inventions of sugar and modern dentistry were pretty nasty though."
] |
[
"What is the social behavior of tardigrades? Do and if so, how do tardigrades interact with one another?"
] | [
false
] | Googling doesn't answer that question and the literature on Google Scholar and pubmed is too high of a threshold to dig through for me as a layperson. | [
"There are multiple species of tardigrade. Some are hermaphrodite, many are predominantly female. It appears that they are mostly solitary, with no real evidence of social behavior aside from mating. Many reproduce parthenogenically.",
"\"Normally the individuals do live separately. They crawl on the vegetable un... | [
"In such cases do we know how the female indicates she's fertile? Is there a chemical or behavioral signal?"
] | [
"These types of questions frustrate me in the best way. As soon as science realized tardigrades’ extremophile properties all of the basic research and ecological studies that come with studying a species were overlooked. It’s not as flashy to study tardigrades as a pioneer species as it is to be the guy who crack t... |
[
"If the gene that codes for six digits is dominant, why do so few people have six digits?"
] | [
false
] | null | [
"You're confusing dominance with frequency. Dominance refers to the phenotype of heterozygotes. If a gene, like the one for achondroplasial dwarfism is simple mendelian dominant it means that heterozygotes (those people with one copy of the A.D. allele and one copy of the wildtype/normal allele) have the same pheno... | [
"Because very few people have that gene.\nA person with 6 fingers will likely have 1 copy of the 6 finger gene, and one copy of the 5 finger gene. That means they have a 50% chance of passing that on to a child. \nIf they do pass it on, the child will have 6 fingers.",
"If both parents have 6 fingers, both parent... | [
"Many rare genetic disorders are in fact dominant. There is a table here ",
"http://www.nature.com/scitable/topicpage/rare-genetic-disorders-learning-about-genetic-disease-979",
" listing just a sampling of the many examples (anything that is listed as \"autosomal dominant\" fits in to the category you are int... |
[
"Does DNA change over time?"
] | [
false
] | Does the human DNA genome change as a person ages? By this I mean could you test the DNA of a child and get an exact full profile match to the same person when they have reached old age? | [
"Every cell division can result in random mutations. Also DNA of single cells can mutate due to radiation and other events. So you would not get a 100% match in a DNA test, wenn you sequence a single cell. Certain cell types also change their DNA permanently (B and T lymphocytes to be able to produce the same antib... | [
"To coattail on this, there is also the issue of telomere shortening and the potential of DNA methylation that can also change DNA from it's \"original\" state."
] | [
"You should also look up epigenetics if you're interested.",
"Short explanation is that it's the study of external factors (lifestyle, disease environment or just normal development) that alter gene expression without directly altering DNA and how those changes can be heritable.",
"It sorta explains how some in... |
[
"Do larger people have larger organs?"
] | [
false
] | null | [
"Yes. It all starts with your skeleton. A larger frame needs larger muscles to move it. Larger muscles will need more nourishment. This leads to a larger digestive tract and a circulatory system with more volume. A larger circulatory system has more RBC's which need a larger spleen to filter them, has more fluid wh... | [
"Depends on the body composition. Height and weight are not the only estimator of organ sizes. Age and sex are also strong predictors of organ size. For instance the equations for total lung capacity gives around 20% extra volume to males compared to females.",
"This is important in thoracic organ transplantation... | [
"Yes and no. Sometimes people who have gigantism or dwarfism can actually have \"average\" sized organs which can cause health issues because they aren't directly proportionate to how the body needs to use them. But as for someone who doesn't have either of those genetic traits, it seems to vary for your size. "
] |
[
"Why aren’t induction cooktops compatible with non-ferromagnetic pots?"
] | [
false
] | I always assumed they would work with any conductive pots, since they use electromagnetic induction to generate eddy currents. Today, when I was explaining to somebody about induction cooktops, I found that I was wrong. It turns out they are only compatible with pots made of iron/stainless, not aluminum or copper. I’m really curious to know why. Does iron’s high magnetic permeability play a role here? | [
"It seems like your question hasn't been answered properly (+wrong infomation). So I will give it a try..",
"",
"Eddy currents are only one contributing factor to inductive heating that would actually favor copper over iron. However in iron as a magnetic material you will generate heat through so called hyster... | [
"Hi, thanks answering my question. Hysteresis loss is a factor I wasn't considering even vaguely, so I was really excited when I read your answer.",
"But Wikipedia article \"Induction cooking\" states that heat produced by hysteresis loss accounts for less than ten percent of total heat generated. So I can't say ... | [
"So I can't say I'm convinced yet. ",
"There is one thing that I have left out so far and that is the so called skin effect. In an AC magnetic field the induced current will flow at the surface of the material. The skin depth depends on the material and impacts the heating ability.",
"The whole thing is pretty ... |
[
"What is the feasibility of creating a Jarvis-like AI for your home, office, etc.?"
] | [
false
] | Just channel surfing and came across Iron Man (which I always have to watch). Just wondering what is the possibility/feasibility of creating a Jarvis like system/assistant for a person's house, office, or whatever? Is this something that is at least somewhat in the realm of possibility? | [
"The problems with AI right are as much about design as they are processing power. We haven't figured out how human-style intelligence works yet, so even having ultra powerful computers wouldn't help us. It's all super complicated (which is not to say impossible) but there are multiple limiting factors."
] | [
"Not possible with today's tech. AI so far is a pipe dream and we are a looong way from making one. ",
"Who knows what the future will bring though? Chances are whatever it is it will be some different tech than our current crop of computers. Quantum computers perhaps.",
"They are within the realm of possib... | [
"It depends on how smart you want it.\nVoice recognition can be done, and lots of people automate their homes in clever ways.\nBut AI technology is in infancy, so you can't make something that is very smart."
] |
[
"How is it possible for so many dialects of English to form in the United Kingdom?"
] | [
false
] | Here in the good 'ol US of A moving out of state is not so uncommon, even moving from one side of the country to the other, allowing for a healthy mix of accents to occur. So I am curious as to how this strange phenomenon to happen. | [
"There's a lot of stuff going on here. Much like the center of human genetic diversity is located in Africa, where the species originated, the center of English linguistic diversity is located in the UK, where English originated. The UK has been home to English speakers for a good 1000 years, and the modern phenome... | [
"A good thing to note:",
"Linguistic diversity is ",
" less pronounced in North America ... ",
"Although there's certainly a lot more dialectal variation in the UK, Ireland, and Scotland, that still leaves a lot of variation. See ",
"this map",
", for instance, where groups of a large number of lines runn... | [
"Pretty sure there's more... Sunderland is different from Geordie and Lancashire from Mancunian, just at a glance. Eg in lancs they say pewer and dewer instead of poor and door. Mancs definitely don't. My Grandad used to say \"thou makes a bitter dewer than a windewer\" if i blocked the tv. I did not understand ... |
[
"What are the ramifications of wearing anti-perspirant every day for say like, 40 years?"
] | [
false
] | null | [
"One of the comments below got me thinking about the topical absorption of aluminum chorohydrate and I found this abstract:",
"http://www.ncbi.nlm.nih.gov/m/pubmed/11267710/",
"One of the last lines: \n\"[the amount of aluminum absorbed from the antiperspirant] is about 2.5% of the aluminium typically absorbed ... | [
"Most soda cans contain aluminum too, but that doesn't mean the aluminum in the can is doing anything bad to you. Is there any evidence that putting aluminum in your armpits causes it to build up in your body?",
"EDIT - ",
"I looked it up",
", and it appears that there is evidence that aluminium chlorohydrat ... | [
"That's really shaky. You have to actually consume Aluminum for it to be toxic, and there needs to be a lot of it since only a very small percentage (like, 0.3%) will get absorbed.",
"It's also important to remember that just because something is toxic in high doses doesn't mean it's going to hurt you at lower co... |
[
"How can splitting and fusion of atoms both create energy?"
] | [
false
] | [deleted] | [
"For a particular atom, you only get energy by going in one direction. ",
"Here",
" is a plot showing the binding energy per nucleon for various nuclei. You can get energy out if you go from a nucleus with a certain binding energy per nucleon to one that has more binding energy per nucleon. For nuclei lighter t... | [
"If I'm reading this right, does that mean that both fission and fusion result in a loss of energy with iron? I'm assuming that's also why stars stop fusing at iron."
] | [
"Nuclear fission and nuclear fusion don't ",
" emit net energy. Nuclear fission only emits net energy if the nuclei are very large. Nuclear fusion only emits net energy if the nuclei are very light. Trying to fuse together two uranium atoms is not going to release net energy, and splitting a helium atom will not ... |
[
"What is the most recent common ancestor between Bananas and Humans?"
] | [
false
] | null | [
"The deeper sections of the Eukaryote family tree are still a bit of a mystery, but generally speaking we would be talking about a protist living well over a billion years ago."
] | [
"I would guess, that the one, whose direct offspring turned into animal and plant cells respectivelly. Because since these organisms are in different kingdoms, that of course can't interbreed, there couldn't be any more recent common ancestor. So their shared ancestor would have lived around 2 billion years ago (ma... | [
"To be clear, this would be the same organism as the most recent common ancestor of ",
" animal and ",
" plant.",
"We know almost nothing about what this organism looked like or how it lived. According to calculations based on DNA comparisons and when in the fossil record the first recognizable plants and ani... |
[
"How do food companies calculate kJ/kCal calculations for each food item?"
] | [
false
] | [deleted] | [
"They burn it. And I mean burn it to ashes.",
"A calorie used to be defined as the amount of energy needed to raise one CC (one gram) of water by one degree Celsius.",
"To determine the amount of energy in say, a Snickers bar, they put a piece of it in a device called a bomb calorimeter, and ignite it. They kn... | [
"Actually, this was the process a long time ago. ",
"Now they use industry-standard/USDA calorie and nutrient tables for the basic nutrients and calculate the totals from there.",
" ",
"Here is the USDA database."
] | [
"They do this by using an apparatus called a bomb calorimeter. What they do is they take this container and place in it a certain mass of the food. Then they submerge this container into a slightly larger container of water whose mass is known. They will then proceed to burn the food using electrical sparks or some... |
[
"Botanists and geologists of Reddit, I need your help: I planted small bonsai in large holes I drilled in feather rock. The plants are all suddenly dying, any idea why?"
] | [
false
] | I bough some at a local hardware store to use as starter bonsai pots - it's a glassy, abrasive, very porous volcanic rock. I drilled large 2 inch diameter holes in the rock and use then for some small starter bonsai (I made sure to drill a drainage hole). I figured the rock would keep the roots from getting too hot in the sun and the porous nature of the rock would retain moisture for the plants so the roots didn't dry out. All the plants I placed in these pots have been doing really well, grew leaves, no signs of stress, etc. Then last week one of the plants looked sickly and is now dead. Last night I went outside and noticed that one of the plants which looked fine the day before is dying - the leaves were all wilted. I have lost 3 plants that were potted in this rock and wanted to see if anyone on reddit could shed light on the issue. I have a few theories but I don't know enough about botany and geology to come to a conclusion. I figure it might be due to: The plant roots are finally reaching the abrasive surface of the drilled rock and causing damage to the roots which leads to death or There are some chemicals in the rock that are being leeched into the soil which is killing the plants. In any case, the plants die suddenly and rapidly and do not give signs of illness or stress before hand. Plants I planted in feather rock are suddenly dying with no symptoms before hand | [
"I have no idea what 'feather rock' is. What you have there looks like it might be a volcanic tuff.",
"There's nothing intrinsically bad about tuff - in fact it forms the basis of some of the greatest vineyards on the planet. However, it is extremely porous, and can be hydrophilic. Is the soil plug still moist?... | [
"I'm not 100% convinced that is natural, but iIf it is, then it's just a glassy pumice/scoria (the stuff you get in tuff). Again, shouldn't pose any issues short of dehydration."
] | [
"I haven't been able to find a technical name for feather rock unfortunately. It doesn't look the same as volcanic tuff, it looks more glassy and sharper. ",
"Here",
" is a website with close up photos of feather rock.",
"The hydrophilicity may have been a problem, but I watered the plants just about every ... |
[
"Two questions about aquifers: 1. Could the use of the aquifers be making a meaningful contribution to sea level rise? 2. Do aquifers replenish themselves at anything like the rate we use them?"
] | [
false
] | null | [
"About three times as much water exists in glaciers compared to groundwater."
] | [
"I can't answer the first part of your question, I don't know the volumes of water stored globally, however, the majority of groundwater levels has dropped significantly over the past fifty or so years - and is doing so an an exponential rate. In some places in California, Texas and India groundwater levels have dr... | [
"It really depends on the aquifer. Most heavily monitored aquifers are near large urban areas. In general the aquifers are not just monitored, but managed. As such they are generally lower than they were before civilization arrived, but fairly stable.",
"I doubt their use affect sea level much at all."
] |
[
"How do squids propel themselves without using the tentacles?"
] | [
false
] | So, I just saw some gif about a giant squid here on and you can clearly see some kind of ""jets"" [citation needed] from the main body. | [
"Jets is the right term. Squids have a moveable opening in their mantle cavity which they can use to direct a jet of water to quickly propel themselves. They usually use the flaps on the side of their bodies for smaller movement."
] | [
"It's basically a squirt gun. The opening is called a hyponome, and it's basically a muscular tube. When it's relaxed, then water flows in. Then it contracts very quickly, and the water squirts out and pushes the squid along. Squirt gun."
] | [
"Well thanks for answering. Do you happen to know how they work?"
] |
[
"Would gases in carbon capture programs that inject gas into the ground change states eventually? Would the gas eventually settle into a liquid or solid?"
] | [
false
] | null | [
"This is completely wrong. ",
"These sequestration wells are drilled into specific geological formations that can trap CO2 and prevent its migration. You cannot get a permit to start drilling without a thorough vetting process from multiple state and federal agencies.",
"These wells are drilled to depths of tho... | [
"This is completely wrong. ",
"These sequestration wells are drilled into specific geological formations that can trap CO2 and prevent its migration. You cannot get a permit to start drilling without a thorough vetting process from multiple state and federal agencies.",
"These wells are drilled to depths of tho... | [
"TL;DR: Generally, it's already a liquid when they inject it.",
"Geological carbon capture and sequestration currently means pressurizing CO2 until it's a liquid, then injecting it into a geological formation that is sufficiently impermeable to contain it.",
"It is worth noting that the field is in a state of a... |
[
"If I practice exerting the exact same amount of force, can I train myself to control the outcome of a coin flip?"
] | [
false
] | or if I can't do it myself, can I make a machine that exerts a precise amount of force on the coin to flip it in a predictable way? | [
"The biggest hurdle would be random variables such as atmospheric pressure etc. Most variables could be predicted and controlled for or minimized though, so if you're keeping the thing in the same room etc, I'm sure you could get an insanely high accuracy with a machine. ",
"And as someone else mentioned, if you'... | [
"The biggest hurdle would be random variables such as atmospheric pressure etc. Most variables could be predicted and controlled for or minimized though, so if you're keeping the thing in the same room etc, I'm sure you could get an insanely high accuracy with a machine. ",
"And as someone else mentioned, if you'... | [
"An easier method of rigging a coin toss is to loss it and flip it on the back of your hand (edit: actually you dont need to flip it on the back of your hand, you can flip it in the same hand with your thumb) ",
"In between catching it and placing it on the back of your hand, run your thumbnail over the surface o... |
[
"What are some documented changes that have resulted from a single point mutation?"
] | [
false
] | I'm an ecology student, and I love evolution and the vibrant examples from it - however, the farther away from the organismal level I get, the harder I find it to conceptualize. The farthest of these are the chemistry-heavy aspects of mutation, which I am not well versed in. What are some examples of how powerful a point mutation can be, in terms of change and how that would effect fitness? How powerful can an amino acid change be in a protein? I have trouble visualizing what kind of change can be created to the point that it would dramatically effect fitness. Let me know if I can clairify at all! Thanks! Interdisciplinary for Biology/Chemistry. | [
"If you look at the ",
"codon table",
", you can see that single nucleotide changes can switch the amino acid quite dramatically - either encoding a new amino acid that is very structurally different (eg CAU -> CAA ",
"histidine",
" -> ",
"glutamate",
"), or even prematurely terminate a peptide via a st... | [
"Point mutations are potentially very powerful. There are countless examples of how a single mutation can cause disease, but I think you're asking about ",
" point mutations, or more generally, how small mutations can act beneficially. ",
"Small tweaks to proteins on the surface of cells that can deny entry t... | [
"Delta F508 is a deletion of a whole codon, not a single point mutation. Sickle cell disease is caused by a single point mutation, an A->T mutation in the beta-globin gene which causes a glutamate to valine amino acid change."
] |
[
"Why do humans smile when they're happy?"
] | [
false
] | [deleted] | [
"From an evolutionary perspective, the smile originates in our primate ancestors. They smile for one of two reasons",
"To mediate aggression: Primates will expose their K9 in a \"smile\" to show how powerful they are (mouth open). This potentially diffuses and aggressive situation, effectively telling the other a... | [
"How do you expose your teeth with your mouth closed?",
"I am honestly confused here. I'm not sure if this is a stupid question or what..."
] | [
"Sorry I could have done a better explanation, submissive - keep your teeth together",
"Human\n",
"http://www.kristinaevey.com/wp-content/uploads/2010/01/smile2.jpg",
"Primate\n",
"http://us.123rf.com/400wm/400/400/phinizrl/phinizrl0810/phinizrl081000009/3747749-trained-baboon-giving-a-big-smile.jpg",
"vs... |
[
"What is the difference in gravity between the lowest and highest points on earth, and would it be noticeable to the average human?"
] | [
false
] | null | [
"It's more complicated than that because the Earth is not a uniform perfect sphere (for example, how does its spheroidal bulge at the equator affect gravity at the poles?). According to a ",
"recent survey",
", gravity on the surface varies from 9.76 to 9.83 N/kg, or about 1%."
] | [
"The radius of the Earth is about 6400 km. The highest point on Earth is at an altitude of nearly 9km (Mt. Everest). The lowest point on Earth on dry land is about .4km below sea level, next to the Dead Sea; the lowest point covered by water is the Marianas Trench, nearly 11km below sea level. [Figures from ",
... | [
"It's even more complicated than that because the gravitational gradient is notonly affeted by altitude, but also by the density of the underlying rocks. "
] |
[
"Is there any basis for going gluten-free, if you don't have for-realsies-been-tested celiac's disease?"
] | [
false
] | My guess is no. But I figured I'd ASK SCIENCE! | [
"for-realsies-been-tested",
"Ahh, the issue of diagnosis is a trickier one than you might imagine. The statistics are miserable: 97% of statistically expected cases are undiagnosed, and the average time to diagnosis for the \"lucky 3%\" is about 10-12 years of chronic pain.",
"The \"gold standard\" test is a ... | [
"I have crappy (ha!) ibs type symptoms, and been tested for everything under the sun (all negative), and have only recently found that if I remove all sources of Fructans (fructose-based starch-like compounds), I feel much better. The diet I'm on strongly resembles a gluten free diet, and I suspect a lot of people ... | [
"Gluten intolerance is similar to lactose intolerance in that the body reacts to gluten.",
"No... they're incredibly different. ",
"Lactose intolerance is related to the lack of an enzyme, lactase, that breaks milk sugar in to simple sugars. ",
"Gluten intolerance is an immune reaction other than IgE (aller... |
[
"Is there anything that can make the moon red-colored aside from lunar eclipses?"
] | [
false
] | I live in Japan and tonight I observed a reddish-colored moon, similar to what I've seen during lunar eclipses ( ). It seems that the last lunar eclipse was about a week ago from now, so I am somewhat puzzled. What am I seeing? What makes the moon appear red this time? Another interesting thing is that it seems that the moon tends to appear reddish around this time of the year in japan. Here's I captured about a month ago on June 19th. Are these all delayed(?) lunar eclipses? Strange weather conditions? Or something else? | [
"The moon is often red near the horizon for the same reason that the sun is red near the horizon (at sunrise and sunset): ",
"Rayleigh Scattering",
". A small fraction of light that passes through the atmosphere is scattered off the air molecules. The shorter (bluer) wavelengths are scattered more often than lo... | [
"Ohh I see, thanks for the thorough reply!"
] | [
"Same reason sunsets are pretty. Its the light scattering from the atmosphere. Here is a link from cornell on the blood moon effect ",
"http://curious.astro.cornell.edu/about-us/46-our-solar-system/the-moon/observing-the-moon/142-why-are-the-moon-and-sun-sometimes-orange-or-red-beginner"
] |
[
"How would two moons affect our earth?"
] | [
false
] | null | [
"Planetary Sci"
] | [
"Planetary Sci"
] | [
"Such hypothetical / speculative / open-ended questions are better suited for our newish sistersub ",
"/r/asksciencediscussion",
". Please post there instead."
] |
[
"Are there anti photons?"
] | [
false
] | Are there anti photons and if there are what do they do differently from normal photons? | [
"The photon is its own antiparticle."
] | [
"A photon and an antiphoton are the same thing. If you apply the operation that changes a photon into an antiphoton, the state stays the same."
] | [
"All known chargeless particles with integer or zero spin are their own antiparticles...or, as I prefer to think of it, ",
". This is partly due to their charge being 0 because +0 and -0 are the same thing."
] |
[
"Shortest wavelength humans can construct and how?"
] | [
false
] | null | [
"At the LHC the colliding protons can eventually lead to photons that have wavlengths much smaller than the size of a proton."
] | [
"You seem to be confusing frequency of emitted light with the power of a laser. While the two are related, they are not equivalent. The power of a laser is determined both by its frequency (how much energy is carried by each photon) and its intensity (how many photons per second are emitted). It's relatively eas... | [
"could we use a large enough capacitor bank (theoretically) to produce any gamma ray we wanted? why don't we see super powerful lasers? "
] |
[
"Serious question. Why does it seem like so many more people are allergic to so many more things?"
] | [
false
] | I'm sorry if this is a silly question. I'd just really like to know if there is any scientific proof, data, or reasoning behind this. It seems like we are constantly being warned now about peanut, shellfish, gluten, etc. I'm 29 now and do not remember hearing anything about any of these growing up. Does anyone have any thoughts? Thanks! | [
"Allergies have ",
"increased significantly",
" in western nations over the last 30 years.",
"There are multiple lines of evidence pointing to the idea that our immune system is disregulated in the absence of parasites to fight. Specifically, This concept is called the ",
"hygene hypothesis.",
"There i... | [
"There is likely to be an element of bias here too. As medical knowledge has expanded, and diagnostic methods and tools have improved, we are likely to diagnose more things that previously went unnoticed. So a portion of the growth is going to be due to us identifying things as allergic reactions.",
"I doubt that... | [
"Thank you very much. That was very informative. I appreciate you taking the time to elaborate so much.",
"The reason I created this thread is because my daughter will be starting kindergarten in just under two weeks and her school is VERY strict about what food can be packed for lunch. I was amazed. I mean, I re... |
[
"Could we force an eruption of Yellowstone if we buried a nuke underground and set it off?"
] | [
false
] | null | [
"I'm going to piggy back off his question to ask my own.",
"Could we relieve the pressure built up in the volcano? In a controlled way?"
] | [
"I'll hop on this one.",
"Relieving pressure in a volcano would be extremely difficult because of the properties of the magma itself. Lets say you drill into a magma chamber with a low amount of pressure. The resulting relief of pressure allows magma to flow up the newly formed tunnel, however it will cool as it ... | [
"That said, you won't find a magma chamber that doesn't have a great deal of pressure already in place. In the case of a pyroclastic flow, you end up with enormous amounts of pressure where no matter what kind of relief you provide, it's going to result in an enormous eruption with amazing amount of potential energ... |
[
"Could the poles of a planet ever be warm enough to inhabit comfortably?"
] | [
false
] | Under what conditions would a planet have warm enough poles for people to live there comfortably? Is this even possible? The reason I ask is I saw a photo of the aurora borealis over barren arctic terrain and imagined a cityscape in the background. One thing led to another and here I am wondering about this. I know "inhabit comfortably" is a vague description, but I do seek a broad range of answers (if this is, in fact, possible). | [
"For much of Earth's history the temperature at the poles was much warmer than it is today. We just happen to be in an ice age right now.",
"If the CO2 level in the atmosphere became high enough, the greenhouse effect would again result in less temperature difference between the poles and lower latitudes."
] | [
"A - \"Comfortably\" is a very relative term - The Inuit live in the high arctic and consider their territory an eminently comfortable place to inhabit.",
"B - If by comfortably, you mean comparable to conditions in the seasonal temperate zone, there were elaborate forests, with redwoods and mixed hardwood-conife... | [
"I bet even the poles on Mercury are hotter than a comfortable temperature...",
"I think it is always possible for the poles to be hotter, but I'm not sure if something large enough to be a planet could have a comfortable temperature at the poles and the equator. Perhaps a planet that has less/different land mass... |
[
"Why don't we ever have super storms on the West Coast?"
] | [
false
] | null | [
"The west coast has a cold current and significant upwelling along the coast, pulling up cold deep-water. There's no scientific definition of a \"superstorm\", but it seems like what the media is talking about is the extratropical transition of a hurricane. Without sufficiently warm sea surface temperatures, you ... | [
"I'm going to remove this question and refer you to this slightly more generally worded question posted within a few minutes of yours: ",
"http://www.reddit.com/r/askscience/comments/12h80e/why_dont_we_ever_have_super_storms_on_the_west/"
] | [
"Awesome, thanks!"
] |
[
"Is it possible that General Relativity is simply not a full picture of gravity?"
] | [
false
] | Perhaps I'm thinking about it wrong, but the idea is that General Relativity is our best description for gravity to date, and it works really well with most things. But then it seems to not work so well on the scale of galaxies which is why we have the theory for dark matter. Newton's laws of gravity work to a certain extent, but it's not complete. the math of relativity covers a larger scale. Is it possible that there is simply a larger theory of gravity that relativity is just not ecompassing? Could the idea of a spacetime fabric be wrong/incomplete? Is the only next step in improving the theory to unite gravity with quantum mechanics? Wouldn't this still leave dark matter unexplained anyways? | [
"Is it possible that there is simply a larger theory of gravity that relativity is just not ecompassing? Could the idea of a spacetime fabric be wrong/incomplete?",
"Yes. Many theoretical physicists are working on this.",
"Is the only next step in improving the theory to unite gravity with quantum mechanics? W... | [
"Sure, this is very possible. In fact, we know pretty much for certain that at the quantum scale it can't be the full picture of gravity, and there's a whole lot of work dedicated to figuring that out. But there's also quite a few people (hi!) who are looking into its behavior on larger scales, to answer, as you su... | [
"unification is expected to occur at extremely high scales of energy that we won't be able to probe with particle accelerators for many, many years. Perhaps centuries.",
"Which is why you need cosmologists.",
"You're welcome."
] |
[
"Is ATP transported in the blood or between cells?"
] | [
false
] | Each cell must make its own ATP, right? Dumb question that I know I should really know. I have a very sketchy understanding of biochemistry. What about other intermediates in the various pathways leading up to the citric acid cyle eg. pyruvate, acetyl CoA? For some reason, I can't find any definitive answer to this on the internet or in textbooks. Many thanks ! | [
"ATP is released from damaged or dying cells. It can also be released through exocytosis. There are some receptors on the surface of cells that use ATP as a ligand like ",
"P2X",
". It's not what you're looking for but ATP can be broken down into adenosine and then taken up by the cell by ",
"ENTs",
" or ",... | [
"it would split into ADP and a phosphate ion shortly after being made anyway",
"This is entirely false. ATP isn't stable in an unbuffered condition like water, but in buffered neutral/blood pH ranges it's stable for a very long time.",
"If it wasn't stable then most molecular biology wouldn't work because there... | [
"no, ATP is a very unstable molecule which is why it's used as a store of energy by your cells. there are no known channels for ATP to leave the cell and it would split into ADP and a phosphate ion shortly after being made anyway.",
"I asked my Biology teacher a similar question on whether ATP injections could in... |
[
"Why is protein an information sink?"
] | [
false
] | null | [
"In ",
"communication theory every transmitted message has at least a source and a sink",
". The sink is the place where the information is actually put to use.",
"As outlined ",
"here",
" the source of the information is the genome, and after encoding and decoding steps during translation and transcripti... | [
"Note that this picture is likely to get more complicated in the future. Epigenetic studies have shown that there appears to be some sort of communication from protein back to the genome. A scent receptor protein that proves to be important to an individual will be more highly expressed in the next generations via ... | [
"So essentially DNA is the source of information, RNA transcribes that information into proteins which then use that information to perform a task, ending the chain of information?"
] |
[
"If a brown dwarf collided with a dying star, would that star be 'revived'?"
] | [
false
] | A star starts to die because it losses/depletes all its helium/hydrogen and it is unable to create fusion anymore. So, if a gas giant big enough collided with a dying star, would that star now have the materials necessary to live for another few million/billion years? | [
"losses/depletes all its helium/hydrogen",
"No.",
"It depletes (fuses into larger nuclei) the hydrogen in its core. It has plenty of hydrogen left in the outer layers.",
"So, a dwarf would only speed up the death of the star as the core will be depleted even faster."
] | [
"Didn't think about that.",
"It likely won't make a difference though, since once the red dwarf \"dies\" it will have too much metals in it to be able to fuse the hydrogen in a sustained manner. At least, that's what my understanding is."
] | [
"Red dwarfs aren't hot enough to fuse helium, so they end their life as a white dwarf that's basically a big ball of hot helium. These can undergo fusion if you add more material.",
"Larger stars like our sun fuse helium during their lifetime (the dramatic \"helium flash\"), so their white dwarf remnants are made... |
[
"Why some people, when drunk, are mellow and merry, and some people are quite the opposite - abusive, aggressive, and violent?"
] | [
false
] | null | [
"It's about the context of the situation\n",
"http://www.newyorker.com/reporting/2010/02/15/100215fa_fact_gladwell"
] | [
"Hard to answer in non-anecdotal way. You know what they say - alcohol removes inhibitions. One can say it reveals the \"true\" (in a sense) personality."
] | [
"Before we answer this, we should ask: what contributes to different personalities/behaviours when people aren't drunk?"
] |
[
"How come other planets have visible craters from space and Earth doesn't?"
] | [
false
] | null | [
"Several reasons:",
"Earth has a reletively thick atmosphere, meaning that most astroids vaporize before they hit the ground.",
"Earth has liquid water, meaning that natural erosion and terraforming happens relatively quickly.",
"Earth has a lot of flora and fauna that change the landscape naturally over time... | [
"I agree with what has already been said but add tectonics, the constant recycling of the Earths surface. It's not quick, but a lot or craters we see on other planets are in the billions of years old range. Also keep in mind that we have massive oceans and humans constantly rework large portions of the exposed land... | [
"I'll add that Earth has active plate tectonics, which means that the crust is constantly being recycled and replaced by new material, unlike other celestial bodies such as the moon.",
"That being said, Earth does have craters. Just not as many as bodies with older surfaces and no plate tectonics.",
"Consider "... |
[
"Several questions about CERN and the LHC"
] | [
false
] | I've always wondered a couple really basic things about experiments at CERN, the LHC, and similar facilities. I realize that these experiments are on an incredibly small scale, but the sheer amount of energy must have some kind of recognizable impact on humans. Thanks! | [
"Atlas",
" scientist here.",
"I think 1 and 2 were answered appropriately by gaze. (But feel free to ask more).",
"On 3: The kinetic energy of one of the protons at full energy in the LHC is about the same as a few mosquitoes in full flight. While that is an insane amount of energy for a single proton to have... | [
"ABlackSwan works at CERN and did ",
"a wonderful AMA",
" that may help you and if not, drop a note there "
] | [
"Thanks! I didn't realize the energy was that size. It's great to have someone right from the source respond. "
] |
[
"Why do whales breach water?"
] | [
false
] | I saw a post on in which a humpback whale throws itself into the air and then 'bellyflops' on the surface. Is there some biological reason that do this or do they just do it for fun? | [
"I don't think we've nailed this one down yet - some possibilities I've read about include dislodging pests or scratching and itch. They also slap their fins and tails on the surface water, perhaps to let other whales know who's boss (bigger whales make bigger splashes). One site suggested that since breaching is... | [
"The full reasons for why whales breach isn’t fully known. ",
"Whales seem to do so more on windy or rough days, when the sound of their voices might not be as effective. A loud crash into the water, however, might be just what they need to communicate with far off groups. ",
"They appear to breach most when ot... | [
"The answers to many of the really interesting questions is \"we don't know\" -- if you find that you're asking a lot of questions that no one knows the answer to, you're probably doing something right in terms of creative thinking and observing the world."
] |
[
"Will an abundance of Oxygen benefit human beings or harm us?"
] | [
false
] | I am aware the troposphere (our ground level) is made up of approx. 75% Nitrogen and 25% oxygen. We breath in mostly nitrogen, but our body only makes use of the littles oxygen that is inhaled. If the ratio were to be switched, would it benefit humans, or harm us? | [
"The greatest danger to humans would not be biological. The greatest danger is the risk of and intensity of fire in an oxygen enriched environment.",
"Oxygen Gas Risks - Oxygen Enrichment"
] | [
"People are often given 100% oxygen in hospitals and as treatment for decompression sickness (the bends) so it's safe to breath for a short time at least. But, at higher partial pressures (above about 1.6 atmospheres) oxygen is toxic and caused convulsions/seizures. ",
"Incidentally atmospheric oxygen concentrati... | [
"Anecdotally, breating pure oxygen makes me feel ... exhausted. It feels great for short time, but it is tiring. I think of it as the oxygen making my body run too fast (have no idea if this is correct - probably not - but it's how I feel. So I think it would harm us. ",
"More scientifically, there are two kinds... |
[
"If most predators have front-facing eyes, why doesn’t the same rule apply for predators like sharks or orcas?"
] | [
false
] | [deleted] | [
"Long distance vision isn’t nearly as useful underwater because light doesn’t travel as far, but vibrations/sound/scent trails do because water is so much thicker and less compressible than air. ",
"So it makes sense that in an environment where it’s easier to detect distant prey by hearing, feeling, and smelling... | [
"This seems sensible.",
"Also: on land the main area of interest is a narrow band along the horizon, while in the water both threats and prey can be anywhere within the field of view, so trading off depth perception for an increase in coverage makes sense."
] | [
"Visibility above 5 metres is unusual underwater. Binocular vision won't be a good way of positioning prey in these conditions. Image clarity is a better guide. ",
"Also interesting: This lack of long distance vision makes having a big brain that does planning a waste of energy. What you see is what you get.... |
[
"How do we know what wavelengths other eyes can see?"
] | [
false
] | [deleted] | [
"You can actually record activity from photoreceptors using microelectrodes and measure their responses to different wavelengths of light. Photoreceptors don't just respond to individual colors; they respond at various strengths to a continuous set of wavelengths. See for example ",
"this chart",
".",
"The ra... | [
"Firstly, you can assess it behaviorally. Humans don't respond to UV, but bee's for example, do. ",
"Secondly, you can examine the eye itself. Human rods and cones only absorb the 'visible spectrum'. Other animal eyes absorb more."
] | [
"As was already said here, we can do behavioral tests (show an animal different lights and observe their reactions) as well as analyse their eyes/retinas at the cellular level (to discover how many receptor types there are and to what part of the spectrum they are sensitive).",
"However, that only tells us what p... |
[
"What makes a metal lustrous? Also, what is the most lustrous/shiny metal?"
] | [
false
] | null | [
"This is correct, although here's a quick followup bit of information in regards to the \"most lustrous/shiny metal\".",
"You would think that since the mathematics of the free electron model implies that higher conductivity induces a smaller skin depth would imply that a metal like gold would be the shiniest. In... | [
"A metal is a lattice of metal 'ions' in a 'sea' of delocalised electrons - ",
"mobile electrons",
".",
"Photons of light do not penetrate very far into the surface of a metal and are typically reflected, or bounced off, the metallic surface, by the mobile electrons and what you get is metallic reflection, wh... | [
"Keep in mind that many things would be lustrous if smooth enough. You're toilet would be lustrous if you polished it a bit. Metals are simply easy to polish because they are soft, so you see more polished metal pieces.",
"As far as the 'most' lustrous metal there really isn't one. The reflectivity of metals be... |
[
"Equilibrium question"
] | [
false
] | So we did a lab on equilibriums and formed this reaction: Fe (aq) + SCN (aq) <-> FeSCN (aq) using colorless Fe(NO3)3 and colorless KSCN to get the Fe and K ions. The reaction was orange-red envelope color. My question is, did KNO3 form as a combination of those ions and if it did, is it responsible for the red-orange color change? And considering that answer, what ion combination must be responsible for that color change? | [
"KNO3 is soluble in water, so in the sense that you mean it, KNO3 did not form. The ion responsible for the red is FeSCN(H20)_5",
" (",
"Wikipedia",
")."
] | [
"Wait, so the KNO3 did not form at all? When the KSCN and Fe(NO3)3 reacted, didn't the K+ and (NO3)3- dissociate though? "
] | [
"The KSCN dissociates to become K+ and SCN-, and the Fe(NO3)3 dissociates as well. Once dissociated, equilibrium favors the K",
" and NO3",
" not precipitating out.",
"The reaction here is between the SCN",
" and Fe",
" ",
" both ions have gone into solution individually."
] |
[
"WHY do gases, such as Helium & Hydrogen INCREASE in temperature when subject to Joule-Thomson effect?"
] | [
false
] | Most of the gases I've dealt with, when subject to a shock pressure difference, cool to such an extent that they nearly freeze. However, several gases (hydrogen, helium etc.) actually increase in temperature when suddenly going from a higher pressure to a lower pressure. I'm also aware that in some cases (extremely cold temperatures and relatively low pressures) that hydrogen and helium do decrease in temperature. What causes this, and how is it different to a gas like Nitrogen (which obviously decreases in temperature) in most circumstances? | [
"It has to do with the balance between attractive and repulsive intermolecular forces of the gas in question. Larger molecules have more electrons and thus a greater tendency to attract each other via the Van der Waals interaction, so the attractive forces are dominant. These gases behave as you would expect and co... | [
"But as a gas expands the average distance between molecules increases and van de waals forces are very short range interactions (they decay as 1/r",
" so why would the potential energy increase in such a case? "
] | [
"If we assume potential energy reaches a maximum after a certain distance, then only molecules that are within that distance will serve to reduce the total potential. A gas in a larger volume will have a longer mean free path and a greater fraction of molecules out of range at any given time. More molecules are at ... |
[
"What does the Partition Function actually mean in a physical sense? Why does it contain all the information for the thermodynamical properties of the system?"
] | [
false
] | I mean this from the perspective of statistical mechanics: I get that the partition function is the "Normalization factor" of the probability calculation for the different states. But I don't get why does that mean that we can derive a system's energy, etc. so easily from it. Is this just a result of some algebraic miracle (that somehow the calculation for the average energy by traditional methods coincides with the one using the partition function)? Or is there some deeper meaning to the partition function that makes it as useful as it is? | [
"Just look at what the derivatives of the log of the partition function are and compare then with the definitions of the statistical average.",
"You can see that d(ln Z)/dβ has the same form as <E>.",
"I’m not sure what kind of intuition there is to be had, outside of just looking at the mathematical definition... | [
"You're missing a minus sign, but, yes, I agree that there really isn't much intuition here. If you simply write down the probabilistic definition of expected value and the definition of Z, then you get the desired relationship right away. It's more or less a combination of the following:"
] | [
"The partition function certainly doesn't know everything about the system, but just many of the system's ``average'' properties. For thermodynamics, these are the quantities physicists care about. Here's a more mathematical way to think about it. The partition function is a sort of ",
"moment-generating function... |
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