title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"What is rayleigh scattering? Why isn't the sky purple or green or yellow? Is the air really blue?"
] | [
false
] | null | [
"Rayleigh scattering is the classical scattering of light off of tightly-bound charged particles. The scattering cross section (probability) is proportional to (frequency)",
", which means that higher frequencies are more strongly scattered.",
"That means that when white light travels through air, more of the h... | [
"True violet does stimulate our red cones, though. They have a little peak down there. That's why it looks like it's on the way to magenta (red+blue) instead of just a deeper and deeper blue."
] | [
"Red cones have a small peak in responsiveness down at the blue end of the spectrum. That's the violet we see in a rainbow."
] |
[
"How cheap a space rocket can be made?"
] | [
false
] | null | [
"First question is what is your definition of \"space\"?",
"http://en.wikipedia.org/wiki/Outer_space"
] | [
"You may be interested in ",
"Copenhagen Suborbitals",
", a non-profit which is trying to launch a manned spaceflight above the Karman line on a shoestring budget. I can't find their budget information right, but I believe it was around 100,000 dollars per year."
] | [
"You can get a weather balloon 'near' space in the outer reaches of our atmosphere for pretty cheap. People do it all the time."
] |
[
"Vacuum Airship?"
] | [
false
] | We're familiar with airships using lighter-than-air gas (Hindenburg, Goodyear Blimp, etc). But, if the balloon/ envelope could maintain an airtight rigid structure and have all the air removed from inside (creating a vacuum), would it float as long as the envelope was lighter than the generated lift? Is such a method o... | [
"Yes, the problem is that the envelope would need to be impossibly light and rigid. A secondary issue would be with such a light material and pressure differential you'd have diffusion of atmosphere into the envelope, so you would need some sort of pump to keep the balloon a vacuum."
] | [
"In theory yes, the problem lies in the structure of the lighter than air transport. Providing the rigid structure that can resist the air pressure around it ends up weighing more than just filling the balloon with a lighter gas. The helium or hydrogen end up acting as part of the structure resisting the air pr... | [
"I have considered this often before, and my idea is that you couldn't possibly build or deploy such a machine for near sea level deployment but if you designed it to somehow float at a higher altitude where there is much less pressure you could potentially deploy a cheap high altitude platform. I would suggest u... |
[
"What specifically keeps viruses from moving from human to animal or vice versa in most cases?"
] | [
false
] | It seems like most of the core components are there for mammal to mammal virus transfer, viruses speciality is adaptation, why can’t I get my dog sick and vice versa? thanks! | [
"It's very crudely similar to the reason you can't get an organ transplant from your dog despite sharing the same organs. There are certain molecules (mainly proteins) that exist on the surface of animal cells that allow other species to recognise them as foreign. By and large the same ",
" of proteins (we say th... | [
"It's more like covid evolved in its host species to a form where it was able to affect humans.",
"To oversimplify things:",
"Picture a virus as a really funky key. Your cells (animal cells) are covered in funky looking locks. These locks are meant to allow good things in while generally keeping bad stuff out, ... | [
"Wow first answer is a champion!! So detailed and really makes sense. Thanks so much. ",
"Follow up question, for something like covid. Was it just waiting to find a human with a similar enough protein match to make the jump?"
] |
[
"Similarity between gravity and acceleration"
] | [
false
] | I have some understanding that gravity can be explained as the effects of a time gradient. I am wondering if it is possible to also look at acceleration in a similar way. My understanding is that the effects of a gravitational field are very similar to the effects of acceleration. I think I've read if you are in a seal... | [
"Okay so let's start with special relativity. If I am moving (uniformly: straight-line, constant speed) relative to you, you will see my length contract along the direction of motion and you will see my time dilate relative to you. All of this happens to make sure that we measure the speed of light to be c.",
"No... | [
"What do you mean by time gradient?"
] | [
"There are no tidal forces to due accelerating through space out side of a gravity field so you would not detect the differences there. As far as an elevator on the ground, there is a difference, I am not sure that is has been measured experimentally for the height of an elevator, but I seem to recall differences h... |
[
"Do electrons, or really any observable object, have compact support?"
] | [
false
] | This is a bit of a silly question, but it stems from a silly I read. Much of it seems to me a profound example of the misapplication of mathematics and physics, specifically the idea of a compact support. Anyway, it got me thinking, do the location of objects in the real world have compact support? Since the probabilit... | [
"Radial wave functions of electrons for instance vanish as r -> ∞ and r -> 0 so have bounded support.",
"Wait, what? I thought that the radial wave function remains nonzero for arbitrarily large values of r (at least for hydrogen 1s), although they do tend to zero in the limit, so as to remain integrable. But thi... | [
"No, \"vanish at infinity\" is the correct term - it's necessary for a function to vanish at infinity if it's square integrable. But the support isn't bounded, so it can't be compact.",
"Edit: Compact requires closed and bounded."
] | [
"Right, this is a one-point compactification, where we add a point \"at infinity,\" which then (under the map t --> arctan(t)) fills in the circle - because without it, you'll get the circle minus a point. This then makes the real line look just like a closed interval, so it's compact now.",
"In 2 dimensions, thi... |
[
"Radiation energy can damage DNA. Can any other energy applied to cells damage DNA?"
] | [
false
] | Looking for insight into what lifestyle choices can lead to (or avoid) cancer. It seems like cells structures would be safe from kinetic energy at the micro level, or am I wrong? Would Sound energy be an exception to this? Thermal energy damages if high enough, but can constant low-level above-average heat, like 100F l... | [
"Beside what G8r and tisvigil specified, mechanical energy can also damage DNA. Asbestos is one of the example where it causes illness mostly by mechanical means. ",
"As a silicate mineral, asbestos is a member the group of minerals that make up as much as 90% of the earth's crust. It is incredibly common, it is ... | [
"Genetic damage due to electromagnetic radiation is an all-or-nothing deal, as a single photon of the radiation has to be sufficiently energetic to break a chemical bond in the DNA chain. Wavelengths longer than visible light, such as infrared, don't have the required energy, and neither do sound waves, unless eith... | [
"This is actually a chemistry/physics question, so you could try reposting there if you want more answers.",
"Basically you should be concerned about any type of electromagnetic radiation with a ",
"wavelength that is shorter than visible light",
". Shorter wavelength = increasing frequency = more energy = m... |
[
"Will all races and ethnicities eventually interbreed enough to have the same basic phenotypes?"
] | [
false
] | Will humanity all one day be the creamy mocha of Tiger Woods or Barack Obama? This is a repost from AskReddit, and I guess I'm looking for a slightly more detailed response. | [
"Nope. Let's say (to really simplify things) that skin color is determined by a couple of co-dominant genes: A and B. Someone with aabb alleles will be pure white, someone with AABB will be very dark, while someone with AaBb will be somewhere in the middle.",
"Let's say the aabb person breeds with the AABB pers... | [
"Well if you look at the above example, you start with two populations, one of which is completely white and one completely black. In the first generation, they're all the same mixed skin tone. However, in the second generation, you again have a proper curve of skin tone:",
"Assuming a population of infinite si... | [
"Well if you look at the above example, you start with two populations, one of which is completely white and one completely black. In the first generation, they're all the same mixed skin tone. However, in the second generation, you again have a proper curve of skin tone:",
"Assuming a population of infinite si... |
[
"If an air bubble is accidentally left in a syringe for a vaccine or any other medicine can it kill me? Or is it rare?"
] | [
false
] | EDIT : I have been supplied with answers so thank you people who commented and goodbye EDIT 2 : Wow I didn't expect this post to blow up I woke up and saw my phone was filled with notifications and when I saw why I got extremely happy so thank you! | [
"No a simple air bubble won’t kill you, either in the muscle or even in the IV. ",
"If somebody grabs a huge syringe and fill it completely with air and inject it in your veins, it may cause problems. But small air bubbles get commonly injected with no side effects"
] | [
"For those who, like me, were unfamiliar with these words:",
"An echocardiogram is a way to check out your heart with ultrasound. ",
"A bubble study is a non-invasive technique where they put a handful of small bubbles in your blood and then watch it circulate through your heart, basically to check for holes. B... | [
"To add to this, t's actually pretty common to have a couple CC of air in a saline syringe for a bubble study during an echocardiogram to check for a PFO."
] |
[
"Are there any human bloods types that we know of, that no longer exist?"
] | [
false
] | Please forgive the grammatical error in the title. | [
"Blood decays without a trace quite early in the process of decomposition, well before any fossilization sets in. It would be a stroke of pure luck to find remains even from a few hundred years ago, let alone hundreds of thousands of years on which the bllod type can be determined. "
] | [
"If you read the article I posted below it goes into the history of blood groups. There's no reason to believe there weren't others, but they were clearly not as successful. Again, blood group is a very artificial classification used to make transfusions easier.",
" none of my posts containing the link are appear... | [
"Is there any reason to suspect/rule out other types having existed in humans?"
] |
[
"Why do we feel pain near our chest region when we are emotionally hurt?"
] | [
false
] | null | [
"Hi, just putting out here, this isn't my native language and I am in no way an expert, so in advance, I apologise if I'm not clear.",
"From what I can mostly recall (and explain in English) from the short time I studied in med school, the pain in the chest region (which I assumed would be the heart) caused by an... | [
"In some cases, it may be literally due to \"broken heart syndrome.\" Its poorly understood, but surges in stress hormones like adrenaline in very very traumatic events leads to damage/weakening of the heart tissue which in turn leads to angina. I have seen a few cases in my career on cardiac MRI."
] | [
"Thank you. This was very informative."
] |
[
"What physiological adaptations would best suit fictional humanoids living in an arctic climate?"
] | [
false
] | null | [
"Two things I'd suggest, an increase in volume relative to surface area, a more carnivorous diet."
] | [
"Just at the inuit: more adipose tissue, a larger liver for gluconeogenisis, adapted to a diet consisting out of mostly animal fats, etc."
] | [
"Sure, short and fat doesn't necessarily specify a particular size. They're relative measures. Since you're overlooking the square-cube law, I suppose you could scale a human up to achieve this goal rather than shorten/fatten one, however at that point you're pretty much dispensing with the science anyway."
] |
[
"Why don't potential Mars settlers simply wear heavy suits to increase gravity's effects?"
] | [
false
] | Hello all, The problems associated with lower gravity both in orbit around earth and long term settlements on mars are huge for the human body. Whilst i understand why a suit wouldn't work in orbit, would a heavy suit work on mars? For example, giving an 11 Stone (on earth) Human a suit weighing ~18 stone (on earth) wh... | [
"if someone stays in microgravity for too long",
"Right, but Mars does not have microgravity (near-zero g). We do not know what the effects of living in Martian gravity (0.38 g) are, because it has never been tested on humans. It may be that with regular exercise, the health risk is minimal, and they may even be ... | [
"It's not clear what the effects of prolonged exposure to Martian gravity would be. Microgravity is clearly problematic for human physiology, but some think that low gravity could be just fine, or have minimal negative effects. We'll have to see. Your idea is one way of dealing with it if it becomes problematic."
] | [
"There's no evidence that exposure to Martian gravity causes heart atrophy, or anything else. As I said, it hasn't been tested."
] |
[
"Idea from r/highdeas"
] | [
false
] | null | [
"I don't get it?"
] | [
"Because it's been removed. I'm saying there are none."
] | [
"I had a feeling that's what you meant. If I submitted the same thing without mentioning highdeas would you of left it up?"
] |
[
"Why do we define the point of no return from a black hole (Schwartzchild radius) with a speed, instead of total energy required?"
] | [
false
] | I've asked this several times, but never got a reasonable answer. Why is speed used to define the point of no return for black holes? Escape velocity is a concept thus: the speed at which you have to go to escape a gravity well . On earth, for instance, we can escape Earth's surface by never actually reaching or exceed... | [
"In general relativity, the curvature of spacetime sort of flips when you cross the horizon. Space becomes timelike and time becomes spacelike. A consequence of this is that the only paths through spacetime are towards the center. Moving away from it is equivalent to going back in time. This is independent of the f... | [
"Contrary to popular belief, the Schwarzschild radius is ",
" defined by speed. It just happens to ",
" the distance at which a calculation of Newtonian escape velocity predicts that a value of c. ",
", the Schwarzschild radius is the value of Schwarzschild coördinate \"r\" (which can be interpreted as radial... | [
"and close to the horizon, is it still defined?",
"where can I read more on this?"
] |
[
"Have we physically measured time dilation in a real time experiment before?"
] | [
false
] | null | [
"Yes, there have been experiments with planes carrying highly accurate atomic clocks being flown around. Upon arrival, the difference in time on the onboard clock and the ground clock matched what was predicted.",
"In addition, satellites that have highly time-sensitive functions are being corrected for the effec... | [
"This guy",
" loaded a few atomic clocks into his minivan, brought them on a camping trip into the mountains, and successfully measured the slight difference gravitational time dilation caused by being at a higher elevation than another atomic clock back at home."
] | [
"As is often alluded to, GPS satellites need to make regular corrections to account for both general relativistic (the large effect) and special relativistic effects like so:",
"https://upload.wikimedia.org/wikipedia/commons/3/36/Orbit_times.svg"
] |
[
"[Biology] Is it theoretically possible to clone someone from their own gamete cells?"
] | [
false
] | Cloning is generically described in lay terms as taking a cell from a living organism and then using its DNA to create an identical copy of that organism. My question is, can a gamete (someone's own sperm or egg cell) be used to clone a person, or do gametes have "incomplete" DNA relative to any other cell in the perso... | [
"Not a clone, but you could duplicate each of the chromosomes to create a diploid cell, and that would work to create a single-parent organism. It would have to be a female, of course, since you'd need either XX or XY, and XX is the only one of those that can be done by duplication."
] | [
"A gamete contains only 1/2 of an individual's genome. You have two sets of chromosomes: one from you father, one from your mother. The processes of ",
"meiosis",
" and ",
"genetic recombination",
" produces gametes that contain only one set of chromosomes. However, each chromosome in a particular gamete is... | [
"Thank you. So does this mean that an egg, but not a sperm, could be turned into a complete organism? "
] |
[
"What kind of stuff actually affects our immune system (in a good or bad way)?"
] | [
false
] | [deleted] | [
"Stuff that effects your immune system:",
"Sun exposure, burns",
"Sleep deprivation or interruption of circadian rythms",
"Acute cold exposure",
"Vitamin D deficiency",
"Here's an interesting one that is emerging: ",
"Acupuncture",
" can impact specific parts of your immune system such as increasing c... | [
"I don't know about cold, but I'm fairly sure stress supresses/reduces immune responses. Cortisol and other stress hormones do suppress the immune system- that's why you see anti-inflammatory drugs with cortisone in them."
] | [
"Another thing that really appears to weaken the immune system is sleep deprivation."
] |
[
"Is there a way we could take a picture of the Milky Way by sending something like the HST \"up\" the galactic plane for a few decades and have it take pictures?"
] | [
false
] | null | [
"Hi, I'd repost this on ",
"/r/AskScienceDiscussion",
"."
] | [
"Will do so in a moment.",
"\nThanks.",
"\n",
"EDIT: Done."
] | [
"Cool, looks good. I'd also look into why it's harder to launch something perpendicular to the plane of rotation for the solar system. "
] |
[
"Why are super-clusters the largest objects in the observable Universe?"
] | [
false
] | After recently watching a video about the Laniakea supercluster, a question arose about what prevents super-clusters from forming ever larger structures. Why for instance don't they form into spirals or discs made up of many super-clusters? Is it simply that the distances involved are too great? Any insights are much a... | [
"Essentially, because 1) the universe hasn't had time and 2) the universe is flying apart rather rapidly, which makes it harder for structure to grow indefinitely. ",
"If you had a static (meaning neither expanding nor contracting), infinite universe with a fairly smooth density distribution, then yes, you would ... | [
"It doesn't really look like the Big Rip is going to happen. It's only going to happen if dark energy happens to be of a variety called ",
"quintessence",
", and at present there's nothing to indicate that that's the case."
] | [
"Structures that can be thought as larger than superclusters do exist; see for example the great walls such as the ",
"Sloan great wall",
", structures observed by galaxy survays that span appreciable fractions of the observable universe. These structures are thought to form inside 'filaments' of dark matter wh... |
[
"Why does glass appear transparent?"
] | [
false
] | It's made from solid matter and even when very thick appears clear. What's the transparent property? And do other animals also see it as transparent? | [
"https://www.youtube.com/watch?v=Omr0JNyDBI0",
" this video will answer your question. apparently it has to do with how the atoms (and therefor the electrons) are arranged. ",
"There are lots of cool physics videos on this channel."
] | [
"To add, glass is NOT transparent to non-visible light, specifically ultraviolet light. That's why you can't get a suntan through a window."
] | [
"From ",
"Cancer Research UK",
":",
"People often think that glass windows protect us from sunburn and skin damage. Although most glass windows do offer some protection, they are definitely not completely sun proof. So we would not advise that you think of them as sun protection.",
"Most glass used for wind... |
[
"What does the orbit of Earth look like?"
] | [
false
] | I know this depends on what it's relative to, but I'm still having trouble picturing it. What I'm looking for is how it travels relative to the universe as a whole, just the plane of the solar system, and just the Sun. Relative to the Sun does it go around in circles or does it make more of a flower pattern? Does the S... | [
"The Earth's revolution around the sun is described as an ellipse. This is a shape very similar to an oval.\nThe Sun's revolution around the Milky Way is also elliptical (roughly). Therefore, the earth's revolution around the Milky Way is a kind of spiral-flower shape."
] | [
"Nearly. The orientation of the ellipse rotates very slowly, once every 112,000 years. This is called ",
"apsidal precession",
"."
] | [
"Does the ellipse come back to the same point relative to the Sun every time?"
] |
[
"What is the best way to divide up voting districts?"
] | [
false
] | Is there a formula that is agreed upon by mathematicians to be the most fair way to divide up voting districts? | [
"Like any question relating to optimization, you would have to first define \"fair\". It's not generally agreed upon what a \"fair\" voting district would even look like. Is it based on closest geographic proximity? Similar income levels? 50/50 distribution of some kind of political leaning? School districts? Dista... | [
"I'm sure you know this, but for the rest of the folks out there, this system is in place in many democracies. It's called proportional representation, and it has its own set of problems.",
"First, there's no filtering. What if a joke slate of Morning Radio Hosts get 2% of votes? Should they really get 2% of t... | [
"Wouldn't it be good to just make a single district and give the parties seats according to the rate they got votes? So with 45% of the votes you'd get 45% of the seats."
] |
[
"Do the yearly flu vaccines vaccinate against the latest version of H and N according to the virus's antigenic drift, or the virsus's antigenic shift?"
] | [
false
] | I've been reading about the difference between antigenic shift and antigenic drift (I think I understand the difference) in regards to flu vaccines but can't find an answer to this question. Does a flu vaccine have an H1N1 (or any other combinations of H and N, just using H1N1 for an example) flu virus with a specific ... | [
"Minor point, the seasonal vaccines aren't made by reverse genetics; they still use classical reassortment. It's a regulatory/patent thing."
] | [
"Keep in mind that the trivalent flu vaccine is made up of different strains that are predicted to be circulating throughout the population in the coming flu season, so it's not always representative of what you might actually be exposed to. The Trivalent Influenza Vaccina (TIV) is the injectable form of the vaccin... | [
"ah cool, thanks for the info!"
] |
[
"If you gather up all the asteroids in our solar system, flung them somehow to a galaxy far, far away ... Would there be a noticeable impact on the orbits of planets or their moons in our solar system?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"It is hypothetical or speculative in nature. We do not allow hypothetical questions because questions that cannot be confidently answered with any available data often invite non-scientific speculation.... | [
"Physics"
] | [
"Physics"
] |
[
"If one were to bring an open mason jar into the deep ocean and place an animal suited to a high pressure environment into it, what happens to the creature? What happens when you close the mason jar with the creature inside of it? What happens if you bring that jar to the surface?"
] | [
false
] | Assuming the mason jar is indestructible. Sorry if this has been asked before, but I've searched and I couldn't find it. Sorry I couldn't word it more eloquently, and I'm sorry if I missed any typos, I'm on mobile. Edit: Thank you guys for answering. Honestly, I don't know why the answer wasn't obvious based on what I'... | [
"No, not if the jar was indestructible as you say. The bubbles would form when the jar was opened releasing the pressure.",
"A real jar would of course stretch a little as the pressure around it reduces, and might even shatter at some point."
] | [
"Nothing much. The creature will not explode as long as the jar is able to withstand the pressure. How long it will live, depends on the relative size of the creature and jar, and how careful you are about not exposing it to light. Eventually it'll run out of oxygen and die."
] | [
"The pressure increases as you descend, and the water in the jar being exposed has the same pressure as the surrounding water because it has the same weight of water above it pushing down on it. Then if you were to scoop a passing creature in to the jar and close the lid the same pressure would remain, because as y... |
[
"When the surface of a body of water freezes, what is preventing the water beneath the ice from freezing too?"
] | [
false
] | null | [
"Heat transfer through water can proceed through two mechanisms. One is diffusion, where the kinetic energy from one molecule transfers to its neighbors through random collisions. While the molecules collide enough that diffusion from one molecule to the next is pretty fast, this transfer becomes slower and slower ... | [
"I'm going to answer a very similar and related question in hopes that it'll give you the information you were looking for: why does the water on top freeze first? Ice is less dense than water (a very unique property that most substances dont have) this allows any ice crystals that form to float to the top, also mo... | [
"Basically, the earth has a fairly regular temperature. If you're out camping and it's 75 degrees out, the ground beneath you will be around 60. That's why you never want to sleep on open ground, it will suck up your body heat and never actually warm up. ",
"Because of this, most of the energy lost in a body of w... |
[
"Does the uncertainty principle just pertain to velocity and position, or are there other \"quality pairs\" that it stops us from getting perfectly?"
] | [
false
] | null | [
"There is a ",
"generalized uncertainty principle",
" which gives the lower bound on the product of the variances of two observables in terms of their commutator.",
"Any two observables whose operators don't commute obey a similar uncertainty relation.",
"This includes position and its conjugate momentum, o... | [
"Observable quantities are represented by Hermitian operators. You can think of them as matrices.",
"When you multiply two matrices, A and B, their product in one order",
"AB",
"is not necessarily equal to their product in the other order",
"BA.",
"If these were numbers, obviously these would be equal to ... | [
"Can I get a tl;dr on what commute means?"
] |
[
"Is there any possible way of generating electricity on a large scale from algae-produced adenosine triphosphate (ATP)?"
] | [
false
] | For example, is there a way that we could get a bunch of green algae massed in a bucket (the size of a nuclear power plant cooling tower) and harvest ATP from their chloroplasts? If it were possible to get energy in the form of electricity from the phosphate groups leaving adenosine triphosphate (ATP), how much green a... | [
"Realize that the energy coming from Algae (well, actually nearly all energy short of geo-thermal and nuclear) is really solar energy.",
"So the question really becomes, is Algae more efficient / cheaper than solar panels for a given surface area. ",
"For the specifics, I don't know.... but it is a more accurat... | [
"ATP is unstable outside of a cell. It's present in low concentrations and gets used up fairly quickly. There's not a significant store of ATP (in terms of concentration) in the cell. You'd be better off trying to get energy from the electron carriers (NAD+/NADH), but even those are transient. The compounds that ar... | [
"This is a different approach compared to what I would consider. Its not by extracting the ATP or the NAD+/H that you would best harvest the energy from these molecules. I was picturing the use of shuttles or transporters or something that drove an electric current. You could hook this up to a circuit made of graph... |
[
"How do trees know it's time to prepare for winter?"
] | [
false
] | While strolling across a yellowish-orangish-reddish park recently, I was wondering how do the trees "know" it's Fall already and it is high time to drop the leaves and prepare for winter? Is it simply connected with the temperature or is the mechanism behind that much more complex? | [
"Plants can sense ",
"photoperiods",
". They balanced the expression of several genes that counteract each other in the light and dark. As the days get shorter they express more of the dark genes which are able to overwhelm the light genes.",
"In a lot of plants, they modify their genome packaging to wait for... | [
"This is also a problem for herbaceous plants and seeds underground that want to grow in the spring. The idea is that after the plant shuts down based on day length it unlocks some genes that will respond to warm temperatures. Coupling these two mechanisms lets the plant be sure that it is only unlocking these gene... | [
"I've never though of it in terms of a process like photoperiodism and gene balance. Thank you for the reply!"
] |
[
"During brain formation in a foetus, what makes each part of the brain different ? Is it a specific neurones organisation ? Why for example speech ability is always located at the same place for each individual ?"
] | [
false
] | null | [
"The the identity of different areas (for example, visual, auditory, motor, sensory) is established during the formation of the brain by diffusible proteins that form gradients from high concentration to low concentration over the length and width of the brain. ",
"Essentially, there are different molecules secre... | [
"Thanks this is useful ! But then how are these differences expressed at cellular level, I mean what physically differentiate the bunch of neurones in the olfactory area than an other bunch of neurones in the audition area ? What are the physical effects on brain cells nature and structure of the presence of severa... | [
"This was a very good question and a great response. He just explained the physical effects on brain cells structure during the presence of these chemicals. These molecules activate transcription factors which literally give direction to neurons as they grow, and thats how the matter accumulates. These transcriptio... |
[
"How do particle detectors work? What do quarks look like on on such a device?"
] | [
false
] | [deleted] | [
"iorgfeflkd describes the ",
"bubble chamber",
" and the ",
"cloud chamber",
", which were some of the first particle detectors. With them, we discovered particles that revolutionized our understanding of everything, such as the ",
"positron",
" (first antimatter particle we found).",
"Nowadays, most... | [
"We never actually see quarks on their own. They are always in groups of two (mesons) or three (baryons). This is because it costs more energy to separate quarks than to create two new ones out of the vacuum. So, if you ever did manage to separate two quarks, new ones would quickly be created for them to buddy up w... | [
"Basically there's a cloud of gas or bubbles, that undergo a phase change when a particle goes past them (for instance, going from liquid to gas). By following the path of the phase changes, you can see various particles. If you put the whole thing in a magnetic field, charged particles start going in circles, so y... |
[
"How does the instant frozen beer/water trick work? Is the liquid below the freezing temperature and if it is why is it not solid?"
] | [
false
] | There are loads of Youtube videos of this trick but I wasn't sure if Ask Science had to be self posts. | [
"First for the Askscience rule- they have to be self-posts but you can put the links in your description. ",
"Now, for the science. The process you are seeing is called ",
"supercooling",
" and it arises because of a somewhat complex scenario which I will do my best to describe. First, yes, supercooled water ... | [
"If you get distilled water in a perfectly scratch-free glass, there's no nucleus for ice crystals to form around."
] | [
"Thank you, got it now."
] |
[
"Why are there diamond patterns on the beach?"
] | [
false
] | I was at the ocean shores beach and noticed some diamond patterns in the sand. . What's the deal? | [
"That occurs when you have wave energy coming in from two different directions. Typically, these two directions are when waves wash up onto the beach at an angle, and then wash back into the ocean.",
"See this as another example"
] | [
"From these papers (",
"one",
", ",
"two",
") it sounds like they are a flow effect and are not related to the waves hitting the beach other than that the waves are what set up the thin sheets of backflowing water where the flow instabilities that create the pattern occur."
] | [
"Yep, that's my understanding of it - it requires backwash in a different direction than the uprush. This ",
" happen if you do indeed have waves coming in at different angles... but that's only a rare exception to the rule and any such ripples formed in such a location will not last long. It was just easier to t... |
[
"What's the deal with \"i\", as in imaginary numbers?"
] | [
false
] | Besides finding the square root of a negative, what can you do with i? | [
"In physics, imaginary/complex numbers, especially in their exponential form, eg. e",
", are very useful for describing waves and oscillations, because they make the algebra much easier. When finding the speed of an oscillation, you needn't mess around with cosines and sines when you can use complex-exponentials... | [
"The main use I've seen for imaginary numbers is that they make it easy to represent a point on a ",
"2-dimensional plane",
" with one complex number made of a \"real\" part plus an \"imaginary\" part. Or similarly, to represent a 2-D vector. ",
"Once you are representing such things using complex numbers,... | [
"As afcagroo says, complex numbers are always useful when dealing with quantities that vary in two dimensions, because these often vary in a sinusoidal manner. Algebra, especially integral and differential calculus, can get a bit fiddly when working with sines and cosines, whereas it is fairly simple when working ... |
[
"How does file compression work on computers?"
] | [
false
] | How can you make a file smaller and still be able to get all the information back? How can you compress a video and still see the same thing (for example, I can compress a 3.5 GB fraps recording into 500 mB and still see the same thing)? If you end up with the same information anyways, why isn't everything compressed a... | [
"There are two types of data compression: lossless, and lossy.",
"Lossless compression is the simpler of the two, though implementations of it are deceptively complex. The basic idea is that, most data contains patterns that can be discovered, then encoded away into smaller representations of said patterns. for... | [
"I'll try to give a toy example.",
"Suppose my file looks like this: \"aaabbbaaabbbaaabbbaaabbb\"",
"The compression algorithm might do something like identify that \"aaabbb\" repeats, and call it \"0\"",
"So the compressed file is:",
"(compression table)\naaabbb : 0\n(data)\n\"0000\"\n",
"which is somewh... | [
"Actually, the two are different. Most data file compression are designed to be lossless while movie compression is lossy. ",
"For file compression, what you get out is ",
" what you had in. Here, the trick is that most human readable data files are rather,... empty....",
"One obvious exemple is if I have an ... |
[
"Do lymph nodes and kidneys have a common ancestor?"
] | [
false
] | It can be difficult to differentiate one from the other unless you know what you're looking for, so I'm wondering whether someone knowns whether they share an ancestor. They're both basically used as filtration units--would it too much of a bound to suggest that they were once the same? | [
"First, common ancestor is not really the correct term because lymph nodes and kidneys are not organisms in themselves. You could ask if at some point in evolutionary history there was an organ that combined the function of these two.",
"Second, the lymph nodes and kidneys are actually quite distinct. I'm not sur... | [
"1) You have to decide if you are using the word \"ancestor\" in a scientific sense or a common language sense. If want to be scientific, then, no, two daughter B-cells are not ancestors of the cell from which they divided; they are clones. Even cells that give rise to more differentiated cell types are not ancesto... | [
"By that logic, two daughter B cells of the same father cell don't share an ancestor. (Hint: They do.) ",
"Why do distinctions make a common ancestor impossible? I agree that they are morphologically differentiated for differing purposes, but that's kinda the point of evolution. ",
"Lymph nodes are most definit... |
[
"When I squint my eyes at night, why do I experience the 'lens flare' effect?"
] | [
false
] | Is it just because my pupils are to large or don't react quickly enough? Why would squinting accentuate this? In case it's relevant, I am also near sighted, with slight astigmatism. | [
": downvote only those comments which detract from the discussion (distracting memes, off-topic jokes, pseudo-scientific mumbo-jumbo, and anti-science rhetoric)."
] | [
"Wild speculation alert: I always thought it was because of light refraction through your eye lashes and/or through tears/eye moisture. This and the fact that you should notice flares a lot easier at night because of the increased contrast due to the lower-light conditions."
] | [
"More Wild Speculation Here: I see this effect on almost all light (real pain in the ass w/ driving into headlights) with it notably worse at night and I have astigmatisms in both eyes. My guess has always been that the two are related."
] |
[
"Are there specific areas where meteorites are more likely to fall or is it completely random?"
] | [
false
] | null | [
"We find new ones that won't orbit us again",
"Meteorites are meteoroids which enter Earth’s atmosphere and make it all the way to impacting with the Earth’s surface. So of course there are no meteorites that are orbiting us again. ",
"ones that we won't see for a very long time",
"Are you thinking of objects... | [
"We find new ones that won't orbit us again",
"Meteorites are meteoroids which enter Earth’s atmosphere and make it all the way to impacting with the Earth’s surface. So of course there are no meteorites that are orbiting us again. ",
"ones that we won't see for a very long time",
"Are you thinking of objects... | [
"It is not completely random, but it does form a distribution. There are areas, which \"shouldn't\" be at risk of impacts, but nonetheless become impacted. However, a few characteristics will significantly raise the likelihood of a meteor crash.",
"So, while it's not an exact science, because there is some level ... |
[
"Could a fusion power plant be used to manufacture plutonium?"
] | [
false
] | Fusion between deuterium and tritium of the sort envisioned in near future reactor designs tends to release high energy neutrons. If you exposed U-238 to these neutrons would it be possible to slowly turn it into plutonium, as in a light water reactor? If not would it be possible to use normal water or graphite to sl... | [
"You could in theory do it, but if you already have both uranium and the capacity to separate isotopes (which you will need to get the forms of plutonium you want) it seems like an insanely inefficient way to go about things. Who would bother? It would be far easier to build a conventional fission breeder reactor."... | [
"Plutonium is made in fission reactors, not fusion reactors."
] | [
"If you exposed U-238 to these neutrons would it be possible to slowly turn it into plutonium, as in a light water reactor?",
"Technically, yes. Capture is much more likely with a thermal neutron than a fast neutron though.",
"Moderating the neutrons could help. Whether it’s a serious proliferation risk depends... |
[
"Which animals are considered extant dinosaurs?"
] | [
false
] | I am familiar with the fact that a lot of birds are evolved from dinosaurs but what other animals out there are less known for this fact? | [
"That's pretty much it. Birds "
] | [
" birds are descended from a group of bipedal dinosaurs called maniraptorans, (see the far right of ",
"this tree",
"). No other dinosaur lineage besides birds survived the end-Cretaceous extinction. Other prehistoric reptiles (e.g. pterosaurs, plesiosaurs, ichthyosaurs) similarly did not survive."
] | [
"At least one other prehistoric reptile survived; the ",
"Tuatara",
":",
"The tuatara is famous because it is the only survivor of an ancient group of reptiles that roamed the earth at the same time as dinosaurs. It hasn't changed much in over 225 million years! "
] |
[
"What is happening to the electrical signals from one's brain when one's muscles are too tired to obey? In other words, what does \"too tired\" mean physiologically in this context?"
] | [
false
] | null | [
"The electrical signals are just fine. They are simply arriving at muscles which have exhausted their ability to respond, either by using up all their available ATP or through injury."
] | [
"Assuming that the muscle has not been poisoned (ie, by VX or another cholinesterase inhibitor), the electrical signal reaches motor endplates and causes acetylcholine release, just like usual. It's just that the muscle doesn't respond, likely because the actin and myosin can't slide due to ATP depletion."
] | [
"There is a bit more to the story.. There is a central component to muscle fatigue. Motor neuron firing rate decreases as muscle fatigue is approached, but attempts to correct it with nerve stimulation haven't reversed the fatigue, so it's thought to be only part of the story.",
"And its most likely not ATP deple... |
[
"If only 4-5% of the air we exhale is CO2, how many times can we breathe the same one breath? And at what point would we pass out."
] | [
false
] | null | [
"Interestingly, your body registers suffocation not by the lack of O2 in the air but by the concentration of CO2 in your blood. Without a way to get rid of CO2, you would still feel the same as if you were holding your breath."
] | [
"The mechanism that drives your body's respiratory system is the difference in concentration between O2 and CO2 at the blood/air barrier within the lungs.",
"I can't estimate the answer to your question, but I can say that your lungs would transport less and less as the O2 and CO2 levels in the two areas began to... | [
"Not so easy to answer (for me at least). I think the easiest way to go about answering the question is to look at an average breath (450ml) and look at the O2 contained therein (94,5ml). The average body uses about 200ml of O2 per minute and breathes 10 times. That means after 5 average breaths the O2 is gone (not... |
[
"Would an ocean of honey still have waves?"
] | [
false
] | null | [
"Well the premise is a hypothetical, and it's a bit open-ended. The closed-ended answer is just that you'd be changing the density and viscosity of the ocean, but not the underlying fluid dynamic equations that govern the ocean and atmosphere. So the same kind of wave phenomena should exist, just maybe with a modif... | [
"Hello,",
"This would be more appropriate for ",
"/r/AskScienceDiscussion",
".",
"Best."
] | [
"Hey thanks for your help! Just curious why it would be better there though. I get the gist of why most of the things in that sub fit there but I can't quite see why my question is more fitting for the discussion sub!",
"Is it not just as much of a yes or no question as anything here? Or is it because I gave a fe... |
[
"Why does total resistance decrease, as you add resistors in parallel to eachother in a circuit?"
] | [
false
] | null | [
"When you add resistors in parallel, you add additional paths for the current to flow through. You increase the conductance (G), and the conductance is related to the resistance by G = 1/R."
] | [
"conductance\nI get this but in terms of what is actually going on what do you mean"
] | [
"There are more paths for the current to flow through."
] |
[
"How is energy conserved in wave interference?"
] | [
false
] | Whilst reading a pop science book on physics and metal, I got to wondering where does the energy go in destructive interference. It had a bit on this in the appendix, which mentioned: A) you have to consider the energy globally for energy conservation to apply. Fair enough i understand this But that doesn't explain wha... | [
"You always have both types of interference, constructive and destructive. You cannot have one without the other.",
"In your example with counter-propagating beams the energy density varies between 0 and 4 times the energy density of a single beam, with an average of 2."
] | [
"No matter how exactly the waveforms look like energy is always conserved."
] | [
"I think pooling your discussion with me and with ",
"/u/mfb-",
" there's kind of two different questions going on. The first is the fact that lines of destructive interference aren't a violation of energy conservation because there are also lines of constructive interference in any beam.",
"Your second quest... |
[
"Why is the speed of light different when it travels through different media?"
] | [
false
] | null | [
"Let's consider this from an intuition perspective (For rigor, you can reference any of the billion books that have been written about light-matter interactions).",
"The basic principles we need to agree on first:",
"\n1.) \"Light\" is an electromagnetic wave that propagates through things (and also through vac... | [
"Thanks for the explanation!"
] | [
"Wooo thanks for the explanation, that was fascinating!"
] |
[
"What is the average distance between where a human is born and where it dies?"
] | [
false
] | I'm interested in both variations of this question: The total amount of distance traveled in a person's lifetime and the absolute distance between the location of their birth and the location of their death. EDIT: Jesus christ, I mean on the surface of the earth. I'm not referring to the Earth's revolution around the c... | [
"Mean = Average",
"Median = Typical",
"Mode = Most Common"
] | [
"Mean = Average",
"Median = Typical",
"Mode = Most Common"
] | [
"I'm not sure that there would be much data on this, the studies that you could undertake would be historical.",
"Also the variation would be massive; geographical occupational and socioeconomical factors would impact majorly.",
"You would have spikes for the wars over the years in terms of distance travelled a... |
[
"Head shapes. What causes them?"
] | [
false
] | Are they caused by genes, development in the womb, post-birth events (e.g. sleeping positions), a combination of these, or something else? Historically, some groups have deliberately shaped infants' heads. There was a "northwest head" in China where the infant (male) was tied to a board to flatten the back of the skull... | [
"All of the above. As with everything in biology, this results from a combination of genetic and environmental influences. ",
"You will have to specify what you mean by ideal. Aesthetics? Brain power? Fitting under doorways? You need a defined purpose to evaluate suitability and ideal-ness. ",
"Remember that th... | [
"I do not have many specific answers for these questions. In part it is because the experiments they would require are unethical to perform on humans. But generally, within the bounds of normal human behavior, I speculate that most of head size and shape is genetic. You could alter that by letting a baby sleep on o... | [
"Some people have narrow heads, some wide. Some people have high foreheads, some don't, some have a large upper-back portion of the skull, some don't. How much of this is genes, how much due to treatment during infancy? For example, I have heard it said that if infants sleep on their sides too much, their heads wil... |
[
"Do light and sound have acceleration"
] | [
false
] | I take a crappy middle school pre-physics class but this question that came up in class sort of fascinated me. Please explain | [
"physics guy here",
"yeah light always travels at the speed of light (lol) ~3x10",
" m/s because all massless \"particles\" (photons) must ALWAYS travel at c. The reason it appears to travel slower through a medium is because the phase of the wave is retarded by passing through the charge density of the electro... | [
"Light changes speed depending on the medium it travels through. It's what makes refraction happen. The speed of light is constant in a vacuum is what you meant to post I'm sure.",
"http://en.wikipedia.org/wiki/Speed_of_light",
"The speed at which light propagates through transparent materials, such as glass or... | [
"The important thing to know about wave speeds is that there are 3 different kinds:",
"1) The phase velocity is the speed at which a single point on the wave moves. Like if you put your finger on a certain point on a wave (like a crest or a trough) and then follow it forward, that's the phase speed. It's always c... |
[
"Why do chemical reactions go with the square of temperature, but diffusion goes with the cube?"
] | [
false
] | I dissect tissue in 4% formaldehyde, and my PI told me that if I were to dissect thicker tissue, I should do so on ice, which would allow the fix more time to diffuse into the tissue but without over-fixing the peripheral tissue. He said something like chemical reactions go with the square of temperature, but diffusion... | [
"Chemical reactions increase in rate at an exponential rate. The Arrhenius equation is a reasonable approximation for most chemical reactions at a small range of temperatures and somewhat describes how they work, and temperature is exponential under it. Diffusion and chemical reactions can both be described by a ve... | [
"Maybe it's the holiday season or something but I can't think of anything that sounds like this T",
" dependence. There is the ",
"van't Hoff equation",
" or the ",
"Gibbs-Helmholtz equation",
" where it's possible to rearrange these equations to have T",
" appear somewhere, but that's about it."
] | [
"All I know about Chemical Reactions I know because of Fogler. "
] |
[
"I was thinking about tattoos, and I started wondering about my dermis."
] | [
false
] | I know your epidermis is continually shedding and being replaced by new skin. I have this notion that my skin in a month will be completely different than my skin today (same structure but a different origin of the materials). I also know that tattoos are deposited below the epidermis. My question is how does the epide... | [
"From my perspective as a non-dermatologist, the dermis is just bland connective tissue. A dermatologist would disagree.",
"What happens to tattoo ink is indisputably cool. ",
"Immune cells ingest them and fibroblasts lay down collagen around them",
". This is a \"classic\" image of a macrophage with tatto... | [
"Cool! That is what I was wondering. That's really weird. I guess when the macrophage dies, a new macrophage eats it, but it wouldn't be able to break it down either. Thanks a lot :D"
] | [
"The outer layer of skin is just dead skin cells interlaced with a protein called keratin. Keratin kills skin cells, but also gives the outer layer its protective qualities (waterproof, etc). It does this via a process called kertatinization, in which skin cell precursors continue to express keratin until they lose... |
[
"Does an octopus have a dominant tentacle?"
] | [
false
] | null | [
"My brief googling showed that Ruth Byrne seems to have done some research in this area based on what she told the National Wildlife Federation in ",
"this article",
" Then when I went to try to find anything published by her the best citation I found was in a 2017 post on ",
"/r/askscience",
" which I have... | [
"It is so weird to me... If each tentacle is independent from the others, how can a octopus coordinate so well every tentacle when each tentacle does what it wants ?"
] | [
"This question was asked previously, ~4 years ago, ",
"here",
"Here's what I said 4 years ago: \nApparently, they do indeed have a \"favorite arm\" they use when exploring new things (",
"source",
"). They also exhibit favored combinations of arms for various tasks as well. As ",
"u/vickinick",
" mentio... |
[
"What are the hurdles for using the Fischer-Tropsch reactions for liquid fuel production?"
] | [
false
] | Liquid fuels are great and I don't think we will every really get away from them because of the energy density. I'm wondering why we are spending so much money into biofuel research, which I feel is a waste of time. The Fischer-Tropsch reaction allows you to produce carbon based fuels from carbon monoxide and hydrogen... | [
"Fischer-Tropsch isn't always uneconomical, but it ",
" is if you're getting both your carbon monoxide and hydrogen out of CO2 and water. ",
"In some places it's economical to burn oil for electricity, too. But just the step of producing hydrogen from electricity is less than 50% efficient by current methods. "... | [
"What do you mean besides cost? Cost is ",
" to do with why this (and any number of other existing processes) are infeasible. Every chemist and chemical engineer knows about the Fischer-Tropsch (and there are other processes as well). If it was economical, we'd be doing it. ",
"We're spending money on biofuel r... | [
"That's not a paper, it's an engineering magazine article. It's not peer-reviewed, nor does it reference anything that's peer reviewed. It doesn't even give any way of knowing how those numbers were arrived at, in particular there's no detail at all about how much energy would be required for the RWGS reaction, whi... |
[
"Could living things sink or dive into lava? Or is it simply too dense?"
] | [
false
] | This link is near the top of right now: The comments are full of people talking about diving in. Would a human actually sink or even be able to get below the surface? Or is molten rock too dense for that? I've wondered this since I was a kid and saw Arnold lowering himself into molten steel at the end of Terminator 2! | [
"Kilauea lava is about 2.6 times as dense as water; the human body is slightly less dense than water. Lava is also significantly more viscous than water.",
"If you jumped off the edge of the crater you'd sink a little because of momentum, but you would easily float in lava. The net force pushing you to the surfac... | [
"Can we make any estimate about how much the gas disolved in, and erupting from, the lava would affect how much you would sink?"
] | [
"Are you in the right thread? "
] |
[
"What would happen if we were to channel vast amounts of electric current into the Earth?"
] | [
false
] | I understand that we ground our electrical circuits into the earth to 'dispel' the charges, but what would happen if we were to ground circuits with large amounts of current? And when I say large, i'm talking millions and millions of times stronger than currents we are used to seeing. Would anything happen? How many ... | [
"This is one of those cases where knowing to ask the right question counts. Grounding is not a matter of current per say, it is a matter of charge. Ground in a circuit is defined as 0 voltage, the entire circuit has an offset to. If ground had a large amount of charge >>than the circuit current would flow out from ... | [
"You need to remember that the charges that make up the current need to come from somewhere. Generally, they came from the ground in some fashion, so sending them back isn't going to do a whole lot."
] | [
"Have you used a ",
"Van de Graaff generator",
" before? If we are getting charge from an outside source I imagine the earth would behave like aVan de Graaff generator. Even though the earth isn't hollow, the charge would still accumulate along the surface (Well, depending on how conductive the material is ther... |
[
"What chemical (if any) dictates the release of fat from fat cells?"
] | [
false
] | If we figured out how aspirin and viagra work among other fantastic pharmaceutical milestones, how is it that we have still yet found a pill to release the fat from our fat cells? | [
"Increase burning fat when you don't need it = thermogenesis = a lot of heat = increase body temperature potentially to a dangerous level. There's a drug called dnp which burns brown adipose (type of fat) and creates a lot of heat and is used to lose weight (and to produce body heat. Was used by Russian soldiers in... | [
"There are lots of substances that release fat from fat cells, (Adrenaline, stimulant drugs like meth) just none yet that do so without unpleasant side effects, risks of other long term harm or prohibitive expense. ",
"Just the absence of insulin does a pretty good job, see ",
"r/keto",
", but it's not pleas... | [
"Glucagon among other hormones will result in fat release from adipose tissue. If the question you're asking is why haven't we made a drug to do this to make people skinny its like someone else said just because its in our blood doesn't mean we will use it. ",
"Having free fatty acids (what fat is outside storage... |
[
"Is there any way, even theoretically, to conduct an entropy neutral process?"
] | [
false
] | I understand that you can decrease entropy, and any attempts to do so will only ever ultimately result in an increase. Instead, are there any processes (involving change, not just a sphere rotating in a frictionless vacuum for example) which could be entropy neutral, even in theoretical realms? I'm thinking there could... | [
"(Sorry, that's a really sad story. I wish I'd never told it now)"
] | [
"All unitary evolution in QM is (von Neumann) entropy neutral, which basically means that the entropy of an isolated system is always conserved according to the QM definition of entropy."
] | [
"If a proton in intergalactic space meets another proton in intergalactic space and they repel each other, that would be an entropy-neutral process too."
] |
[
"If light is photons and photons are massless why cant light escape from a black hole?"
] | [
false
] | null | [
"Linked in the AskScience FAQ: ",
"https://www.reddit.com/r/askscience/comments/1heqk0/if_light_has_no_mass_then_how_is_it_affected_by/"
] | [
"Sweet."
] | [
"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",
... |
[
"How can farming insects be more energy efficient than mammals?"
] | [
false
] | I have read that raising crickets would produce less of an environmental impact than cows, pigs or chickens. You can measure all of the impact into simple energy used to make a kilogram of meat. How can this be true considering economy of scale? One kilo of insects takes thousands of bugs, wouldn't having a single l... | [
"Insects are efficient at turning feed into bodymass 1.7kg/kg for crickets compared to 10kg/kg for beef. We can eat 80% of a cricket but only 40% of a cow.",
"Other environmental considerations in favour of insects: They do not require such large amounts of pasture or water. They do not produce as much manure (an... | [
"Among other factors, cattle grow more slowly than insects. Even in modern farming, where cattle can be slaughtered for meat at just over a year of age, while a field cricket is mature at roughly 12 weeks.",
"A lot of what a cow (or any animal) consumes goes into the activities of being alive, rather than simply... | [
"I have my lecture notes in front of me (I'm not sure if i am allowed to link them). Beef is 4.3% efficient. Pork is 8.5%, Chicken in 15%. Corn is 100%. Fish isn't listed, but 100% doesn't really make sense, unless they are photosynthetic."
] |
[
"Can some people be naturally immune to a virus without ever contracting or coming in contact with it before (vaccines included)?"
] | [
false
] | This might be a silly question that I just havent thought through and googled furiously enough but I read an article recently that said: "Scientists from the Institut Pasteur and the CNRS unraveled the immune responses of 200 African and European individuals. They show that there is indeed a difference in the way these... | [
"The HIV resistance is not immunity, it's resistance. Nobody in the field calls it immunity.",
"Immunity means a function of the innate immune system or the adaptive immune system. People with natural HIV resistance (i.e., the delta32 CCR5 gene) are not \"immune\" to HIV because no part of the immune system is pr... | [
"The HIV resistance is not immunity, it's resistance. Nobody in the field calls it immunity.",
"Immunity means a function of the innate immune system or the adaptive immune system. People with natural HIV resistance (i.e., the delta32 CCR5 gene) are not \"immune\" to HIV because no part of the immune system is pr... | [
"I agree with this except it’s wrong to say that someone is immune to COVID if they can spread it! If they can spread it, it means they are infected, which means they are not immune."
] |
[
"Has there been any research on methods for obstacles to identify themselves to an autonomous vehicle?"
] | [
false
] | I’ve been reading a lot of articles about artificial detection in AVs and all the research is focused on AVs using their onboard sensors to detect essentially uncooperative obstacles. What I’m wondering is if there’s any research related to signal emitters or other devices which could be attached to pedestrians/cyclist... | [
"Yes, well sort of. Renault has developed what they call a level 4 autonomous vehicle, which can drive autonomously on a highway with sensors riddled along it so its as much the road knows the car is there as the car knows whats on the road ahead. In terms of something like say a littlee sticky or warning marker yo... | [
"To be fair, you can do the same thing to people-operated cars with a box of roofing nails."
] | [
"Also can I just start dropping stickies across the highway and watch all the autonomous cars come to a halt? Seems like an easily exploited system"
] |
[
"Is using an \"expired\" brita filter better than drinking straight tap water?"
] | [
false
] | I've been using the same filter for about 2 months longer than it's life expectancy. I would buy a new pack from Costco, but I don't have any more organs to sell. Should I just take it out and drink from the tap, or does it still provide some filtration? | [
"...I was with you up until the very end. You list a set of things that a Brita pitcher can accomplish that no one disputes, and then say its probably not doing anything anyway. Is this because the OP probably doesn't live in a place with very hard water that has some organic contaminants? I'm not sure that thats n... | [
"I think you put the wrong word in quotations. Is drinking water from an unexpired Brita filter \"better\" than normal tap water?",
"In the vast majority of cases in the US or any other industrialized country, no. ",
"Brita filters have two basic components: an ion exchange filter, and a charcoal filter. Th... | [
"Say what you want, but a Brita-like water filter makes tap water that tastes like a swimming pool acceptable and filtered water also doesn't have that skin on the surface of a cup of tea. As a tea enthusiast, the latter is reason enough for me to prefer filtered over non-filtered water. The tea tastes better, too,... |
[
"Do you think you'd be more intelligent if you had two brains?"
] | [
false
] | [deleted] | [
"And when one sleeps :P You can eliminate sleep and use that time to develop yourself ;)"
] | [
"And when one sleeps :P You can eliminate sleep and use that time to develop yourself ;)"
] | [
"Yes."
] |
[
"Why does the glare from the sun make me sneeze?"
] | [
false
] | [deleted] | [
"I didn't find any simple explenation in english, but found a few in my own language (Swedish) so I'll translate them roughly.",
"The simple answer is that the scientists don't know.",
"About 1 out of 4 suffers from this and it seems like it has to do something with the nerve system that over reacts when you tr... | [
"It is called Photic sneezing I believe. It is not something that all people posses. If I recall correctly your optic nerve is closer to your nasal nerves than is normal, therefore when your optic nerves are suddenly over stimulated by a bright light it \"jumps\" to your nasal nerves causing a sneeze. ",
"Source... | [
"Photic Sneeze Reflex"
] |
[
"Do gluons carry the strong force or only mediate it?"
] | [
false
] | null | [
"Carrying a force and mediating it are both the same thing. Gluons are to the strong force as photons are to the electromagnetic force. "
] | [
"Ok. Thank you for clarifying. I hope someday to go into particle physics and this whole \"force carrying\" thing really threw me off"
] | [
"No problem :)."
] |
[
"Can a counterbalanced lever be thrown further than an uncounterbalanced?"
] | [
false
] | null | [
"I realize this isn't super helpful, but the answer depends a lot on the specifics of the situation, eg:",
"To still give you a concrete answer, let's assume you take a modern throwing javelin (which if I recall correctly are symmetrically balanced) and replace the metal in the front half with a significantly lig... | [
"Interesting, are ancient war javelin balanced in the same way?",
"Anyways, 1. Like 530 grams 2. Throwing knife throw 3. Adding extra weight"
] | [
"I don't actually know how to to the math on this, but for 500g I suspect that heavier is better. The reason for this is that the limit of how fast you can throw a light object is largely determined by the speed at which you can move your arm, but a heavy object moving at the same speed as a lighter object will hav... |
[
"Is it theoretically possible to be struck by lightning while inside your house?"
] | [
false
] | null | [
"Yes, it is. And I'm not speaking theoretically. The second time I was hit by lighting, I was in my basement.",
"(The first time was a bit of a shock. The second time, though, was revolting...)",
"I live on a mountain and have a tall pine tree next to my house. A very active storm blew in, and since I've lo... | [
"Possible, but unlikely. If you are touching the plumbing (or the grounding conductor) with one hand, and touching a bare wire that goes to an antenna with the other, AND your hands are wet, then it seems possible that you could be used as a means to resolve the difference in potential that causes an electrical sto... | [
"Yes. If the plumbing comes into contact with the ground, and there's continuity between one's self and the ground (through the water/plumbing), then yeah, it would significantly raise one's chance of being struck by lightning. Not a guarantee, by any means, but higher chances. In the end, it would depend on how hi... |
[
"Is it possible to pass a very thin wire through a person's body without killing them?"
] | [
false
] | I had this thought the other day. Would it be possible to pass a very, very thin wire straight through a person's body, let's say around the middle, and have them survive despite technically being sliced in half? If so (considering very minimal damage would occur), would it be possible to pass 10, 20 or 100 wires simul... | [
"You get cut in half, you die"
] | [
"You're cells have proteins holding them together with other cells. It's more than displacement. No matter how thin you get, you'd have to pass through (and break) these proteins. You can't just slide in between cells."
] | [
"Wouldn't it almost instantly seal back together?",
"Not really. You'd be severing many molecules in many cells, including polymers in the tissues and bones that hold our bodies together. Your cells and tissues are very dynamic structures, and would require time to repair themselves, if they could even survive th... |
[
"Are there any animals that are known/expected to exist based on remains and other evidence, but that we don't have any sightings of?"
] | [
false
] | [deleted] | [
"Charles Darwin predicted the existences of a moth with a 10 inch tongue based on the existences of a flower with a 10 inch nectar spurs.\n",
"http://faculty.washington.edu/jrw/110/darorch.htm",
":EDIT",
"http://en.wikipedia.org/wiki/Hawkmoth",
"\"[A. sesquipetale has] nectaries 11 and a half inches long, w... | [
"Before only a few years ago, the only evidence we had of Giant Squid was a few washed up dead bodies, some whales with huge squid-like bite marks, and old fisherman stories. Now we have seen them in the wild and know that they exist.",
"As for your question, I can't think of any off the top of my head. You're ge... | [
"This moth named ",
" was recorded on infrared video in its natural setting for the first time by Phil DeVries. The footage was included in ",
"this PBS Nature video",
" uploaded in 2008."
] |
[
"Why is blue light the first to get absorbed into the atmosphere through rayleigh scattering, but it penetrates water deeper than other colors?"
] | [
false
] | I am out fishing and there are guys with lights that they use to light up the water in the back of the boat when it is dark out so they can see the fish, but all of the lights are either blue or more commonly green. I know from my stage crew days that blue is very hard to produce well, and that the human eye is most ad... | [
"Really good question!",
"In terms of scattering, yes, blue light is scattered more easily in water and in air. However, absorption is very different for water and even water vapor.",
"In water, there is a strong preference for absorption at the lower energy red end of the visible spectrum. The reason for this ... | [
"Interesting to add to this very complete answer is that heavy water (made from deuterium) is colorless since the overtone band is shifted in the infrared, confirming that this is the origin of water blue color"
] | [
"This page has a copy of the image: ",
"http://www.dartmouth.edu/~etrnsfer/water.htm"
] |
[
"What the heck is toothpaste and why is it good for our teeth?"
] | [
false
] | null | [
"toothpaste is an abrasive. Like very fine sand paper, it rubs off the dirt and grime. You can also use it to polish metals like copper."
] | [
"Toothpaste is a mixture of chemicals to clean your teeth effectively. However a common ingredient is fluoride, which prevent cavities. There are also anterbacterial angents in toothpaste."
] | [
"I'd like to add that the fluoride prevents cavities by building the enamel back on the teeth. The outside of a tooth is kind of like a sponge with hard stuff filling in the spaces. Plaque eats away at that hard stuff and fluoride builds it back there, becoming harder than the original enamel."
] |
[
"particle spin"
] | [
false
] | How does a particle's spin affect its behavior? | [
"If it has integer spin, then it is a boson. It can occupy the same state as another identical boson. You can think of it in some cases as occupying the same point in space (and having the same velocity, and all other properties equal). Photons, gluons and compound particles like certain atoms (like Helium-4) fit t... | [
"But chemistry is so ",
" and has such a very large body of work behind it; people ",
" chemistry is complicated stuff and tend to shut off their sensory input when you bring it up. Meanwhile, neutron stars are exotic, sexy beasts that excite the imagination because \"whoa man, the universe is ",
"\"."
] | [
"You can align the spin axis with a magnetic field then rotate the magnetic field."
] |
[
"What is causing the clearly defined line of bubbles part of the way up my glass of Coke?"
] | [
false
] | Quite a simple question this one, but I couldn't find the answer with a quick bit of googling. I poured a glass of coke straight from a bottle in the fridge yesterday, and as soon as I finished the pour, there was a very defined line of bubbles about a quarter of the way up the glass. There were just no bubbles in that... | [
"For bubbles to form on a surface there needs to be nucleation sites. This could be some dirt or imperfections on the glass surface. So it could be that the manufacturing process of this glass caused a strip of the glass to be more rough than the other parts - causing more bubbles to nucleate there. Or whoever clea... | [
"I’m actually thinking that area might be where another glass sits when they’re stacked in the cabinet. That would naturally lend itself to more nucleation sites by wear and tear from contact between the glasses."
] | [
"In the restaurant/bar business, there are glasses that are clean enough for water, soda, etc., and then there's \"beer clean.\"",
"If a glass isn't cleaned well enough and a beer is poured in it then the head on the beer won't form properly.",
"I presume that these phenomenon are related."
] |
[
"If I drink enough blue food coloring, will my pee turn green?"
] | [
false
] | [deleted] | [
"As far as I can tell from my textbooks the only blue food coloring in use in the US is excreted in the feces.",
"You can turn your pee green if you eat too many Clorets, which contain chlorophyll. "
] | [
"Try it"
] | [
"You can turn your pee pink by eating red beetroot. So yes, certainly some pigments can pass through into the urine. Other pigments may be broken down, it would depend on their chemical structures I'd guess. "
] |
[
"Ask Anything Wednesday - Engineering, Mathematics, Computer Science"
] | [
false
] | Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical post? No question is too big or small for AAW. In this thread you can ask any science-related question! ... | [
"The FAQ for the ",
"/r/learnprogramming",
" subreddit has answers to these questions, and many more."
] | [
"The FAQ for the ",
"/r/learnprogramming",
" subreddit has answers to these questions, and many more."
] | [
"Computer Scientist here. It really depends on what you're trying to do. Do you want to have general foundational knowledge that will give you the tools to pick up pretty much any language with relative ease? Go get a computer science degree. It'll take 4+ years, it won't be easy, and if you don't like math you're ... |
[
"What is happening in this nuclear explosion?"
] | [
false
] | a) There seems to be an initial explosion b) There seems to be a secondary explosion - what is happening here, why is there a second explosion? c) The center of the explosion seems to shift up and a little to the left, why? d) There seems to be some sort of vacuum that is filled, but how could this be if they are in sp... | [
"I am pretty sure a, b, and c are explained by the fact that this is actually two separate explosions spliced together for the gif without any fade or other way to separate the explosions. ",
"https://www.youtube.com/watch?v=KFXlrn6-ypg",
" has the same two explosions but in the reverse order.",
"The blue stu... | [
"It is actual footage of the Starfish Prime test, but seems to be spliced together from two different views. It's pretty obvious that they're two different views since the latter part of the shot shows the smoke trails from some of the rockets carrying instrumentation that they shot up prior to detonation, but the ... | [
"The blue stuff is likely an aurora effect",
"Is it possibly cherkenov radiation? I read that prodcues a blue light when changing medium. I saw this on ",
"/r/space",
" yesterday and apparently this was detonated in the upper atmosphere. If this is being recorded from the ground the change from vacuum to air ... |
[
"How many neutrinos does it take in order to hurt/kill someone?"
] | [
false
] | Weird question. | [
"https://what-if.xkcd.com/73/"
] | [
"I ",
" enjoyed this part, although it isn't relevant for the question:",
"Here's a question to give you a sense of scale:",
"Which of the following would be brighter, in terms of the amount of energy delivered to your retina:",
"A supernova, seen from as far away as the Sun is from the Earth, or",
"The d... | [
"What is the relationship between brightness and neutrino emission density? If it is somewhat related, the comparison is sound."
] |
[
"Is the stereotypical \"vat of acid\" in movies really an acid? Or would it more likely be a base or oxidizer? Does such a substance exist? And If the movies messed up, how do you think this happened?"
] | [
false
] | So this requires a bit of an explanation. I was talking to a friend at one point and he mentioned that the stereotypical "vat of acid that will melt your skin off" is actually most likely a very powerful base. I asked my dad who is pretty good with chemistry and likes it. He works in the medical field so I trust what h... | [
"This is a common misconception about HF. Yes it is highly corrosive and dangerous, but it's for specific reasons. ",
"It corrodes glass because glass is full of Si-O-Si bonds and HF can convert those to extremely stable Si-F bonds. Other common acids (HCl, H2SO4) don't have that driving force. The final product,... | [
"Yeah, even then. Fluoride doesn't have any special interaction with proteins, lipids, etc--the main stuff your body is made of. So you're just interested in the sheer strength of the acid/base. This paper, ",
"see if the link works (pdf!),",
" suggests that acids and bases are about equally good at hydrolyzing... | [
"Hydrofluoric acid might be what you're thinking of. It is a highly corrosive and dangerous acid. Though technically a weak acid, it can burn through most things, including flesh and bone as well as glass. If you watch Breaking Bad, Season 1 that's what they used. A vat full will definitley get rid of a body. ... |
[
"Did they have to bring the air up to the international space station?"
] | [
false
] | how did they get the air to the international space station? | [
"Sure. And they keep bringing up \"air\" - now mainly as water, which is split into hydrogen and oxygen at the station. The oxygen is needed for the crew, the hydrogen is used in the CO2 removal system. A bit of nitrogen covers losses to keep the interior at an Earth-like gas mixture.",
"It is part of the usual m... | [
"There are prototypes, but it is difficult to get enough oxygen and to remove enough CO2 with that.",
"Most of the oxygen is recycled already, but the ISS needs the hydrogen from water to get rid of the CO2 (overall reaction: CO2 + 2 H2O -> CH4 + 2 O2, the CH4 is released to space). The ISS has a nearly closed cy... | [
"How far are we from having algae or plants in a grow module to produce air or would it require too much water to maintain?"
] |
[
"With the eventual arrival of colonists on Mars, would they be able to download content like movies/music from Earth? How would data transmission play out?"
] | [
false
] | null | [
"Hi Suddenly_Another_0ne 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 o... | [
"Planetary-Sci"
] | [
"Planetary Sci"
] |
[
"Why is it that morning dew only gathers on the front and rear windscreens, not the side windows, of cars?"
] | [
false
] | My best hypothesis is that it relates to surface area; I drive a wagon, so it's not the angle. I stepped outside just now (0630) and noticed all the cars fit the thesis question. | [
"I've noticed that if you park next to a wall the side next to that wall won't form dew while the exposed sides will. Are you parking next to other cars side by side?",
"I think it's related to radiative heat transfer: any windows that have a clear view of the sky will cool down faster than those seeing other obj... | [
"This is the correct answer for this question. The front and rear windows are pointing toward the sky so they radiate heat to space and thus can be colder than surrounding air. ",
"The next thing about this is relative humidity. Colder air holds less water vapor than warmer air. For example a kg of air in tempera... | [
"For the people that live in the atacama desert, specifically the residences of Lima, a advertising company teamed up with a university to build a billboard that takes advantage of the high humidity to generate clean water for residents. This is an active system unlike the passive one you described. ",
"http... |
[
"What exactly is meant by ATP releasing \"energy\" for other chemical reactions to use?"
] | [
false
] | Does "energy" mean heat? If so, I am not sure what heat means at the level of individual molecules - velocity maybe, or vibrational energy? If so, how exactly can that help another reaction take place? | [
"The \"energy\" is basically chemical potential (or degree of chemical reactivity) that can be used to drive other chemical reactions (biologically, heat is just a waste product). ",
"Adenosine Triphosphate (ATP) has a reactive phosphate chain that can be used to \"easily\" add phosphate to many different molec... | [
"The simplest way to think about how ATP can do work (or release energy) is to consider that there are three phosphate groups right next to each other. Each of these phosphate groups has a lot of negative charge, so they tend to repel each other, kind of like a spring. This means ATP stores a lot of potential energ... | [
"To add to what ",
"/u/practically_sci",
" said, one way that ATP is used as an energy store is in DNA synthesis. Clipping together a DNA strand is a very high-energy process and would only happen very slowly (if at all) if left to go by itself. The body solves this problem by attaching ATP molecules - they'r... |
[
"Why is it whenever you see powerful lasers used in labs or other areas they are almost allways green? Is this due to how they are produced or is green light a better wavelength for sensors to pick up?"
] | [
false
] | null | [
"A Nd:YAG laser is often used as as it can make ~10 nanosecond pulses at low frequency. (so it compresses all your power into a few short burst of very high power). Example: A 4W laser pulsed at 10Hz with a 10 ns pulse gives a 40 MW intensity during the pulse. Incidentally, this is why pulsed laser are so dangerous... | [
"Side note: if you need high power pulsed red light, you can power a dye laser with the 532 nm light from a Nd:YAG, thus resulting in applications with red light also having green lasers present on the laser table.",
"For pulsed high power blue light you can use the third harmonic (UV) of a Nd:YAG to power a dye... | [
"If you want to probe the dynamics of an excited state of a molecule that only lives for a very short amount of time (let's say 200 femtoseconds), you need to excite it with a pulse (10-30 fs long pulse for example) and get the hell out of there before you start \"looking\" at it. If your \"pump\" pulse isn't out o... |
[
"Why is yellow so hard to see?"
] | [
false
] | [deleted] | [
"There are no valleys in the overall sensitivity (i.e., the luminosity function). The second figure in that link is (unfortunately) overlaying three different sensitivity functions, which makes it look like one function with peaks and troughs. Here are the three curves shown as separate lines: ",
"http://upload.w... | [
"You're right that yellow is off-center, and that's precisely what you should be seeing. There is no rule that says your eye's response to stimulus in the visual spectrum must follow a perfect bell curve. In actuality, our eyes are most sensitive to the yellow-green area (a bit on the \"red\" side of pure green).... | [
"He gave the answer to that -- we use the yellow-green region to determine brightness in the first place, and we're most sensitive to individual colors closer to the center of each cone type's range."
] |
[
"With an electromagnetic wave, what is actually waving?"
] | [
false
] | Whenever an electromagnetic wave is depicted it's always an up and down motion over time. What is the vertical component? Is it actually moving up and down in space? Or, is the y-axis simply a measurement of some value? | [
"An electromagnetic wave is a coupling of an oscillatory electric field with an oscillatory magnetic field, the relationship between which is given by Maxwell's equations. Those ",
"3D depictions",
" we usually see are really just showing the propagation of a wave along a single dimension, with the amplitude al... | [
"Yeah, it's kind of confusing for beginners and laypeople. Even after studying Electrodynamics I sometimes have to stop myself from thinking of physical objects waving up and down in space."
] | [
"Yeah, it's kind of confusing for beginners and laypeople. Even after studying Electrodynamics I sometimes have to stop myself from thinking of physical objects waving up and down in space."
] |
[
"In winter, do plants continue photosynthesis?"
] | [
false
] | null | [
"Plants has even a protection mechanism which is called photorespiration, that prevents from the (let's call it) \"overburning\" due to an excess of photons ",
"The protection mechanism is called ",
"non-photochemical quenching",
" with the help of ",
"xanthophylls",
". ",
"Chlorophyll florescence",
"... | [
"Afaik (and please correct me if I'm wrong) photosynthesis isn't something you can just \"stop\". Green parts which contain chlorophyll don't \"choose\" to photosynthesize or not, it's something very ...\"mechanical\": when chlorophyll is hit by a photon, it has no choice to react. Plants has even a protection mech... | [
"A lot of processes can happen during photorespiration but the starting point is RuBisCo and the problem is too much oxygen in leaf tissue (there are studies on growing plants in chambers with lower oxygen levels to help get around photorespiration issues). The Calvin cycle then tries to make use of the oxygen inst... |
[
"Are there any synthetic materials that have the properties of a human thumbnail? Sometimes scraping things off of a surface my thumbnail works better than anything else I have."
] | [
false
] | null | [
"I do not know but I would like to point out that a possible reason for the efficacy of your own nail for scraping things is because it is attached to your finger quite rigidly. In contrast, any tool you use is being held by the soft pads of your hand and fingers and thus might absorb shock and be more prone to sli... | [
"Guitar picks can be very similar. Pliable, but with resistance and not so hard that it will scratch most plastics. \nThey come in a number of different finishes & thicknesses so you would have to go to a store and lpay with them a bit to get the right feel. "
] | [
"Curses! I came here to say this."
] |
[
"Does DNA ever switch direction mid-strand?"
] | [
false
] | null | [
"Wait, what? ",
"Bases in DNA are ",
" connected 5' - 3'. Or you can think of it as 3' - 5' if you prefer. It doesn't really matter, but retrotransposons or \"negative strand DNA\" or anything else aren't special in terms of how they're read or translated. We usually think in terms of 5' to 3' because that's th... | [
"I agree that DNA in the genome is always structurally linked 5' to 3'",
"RNA though, specifically messenger RNA or mRNA is (in eukaryotes) always capped with a 7-methylguanosine in a 5' to 5' way. ",
"http://www.nobelprize.org/educational/medicine/dna/a/splicing/splicing_endmaturation.html",
"\n",
"http://... | [
"dazosan's right. DNA are always connected 5' to 3', and a 3' end can then connect to another 5' anyway, that's why circular plasmids exist in the first place! To answer the OP's question directly, a 5' cannot connect to another 5', neither would a 3' connect to a 3'. ",
"Concerning directions, I was thinking ab... |
[
"How well do we know physical constants?"
] | [
false
] | null | [
"It depends on the constant. The gravitational constant for instance is relatively poorly known because it is so weak. It's only known to about 5 decimal places. Atomic constants (elementary charge, atomic masses, boltzmanns constant, etc.) can be much more accurately measured because they relate to atomic transiti... | [
"For particle-related properties, you can get that information ",
"here",
". As an example, it lists the mass of the proton (under \"baryons\", box \"p\") as m= 1.00727646677 ± 0.00000000010 u, where u is the atomic mass unit. This is quite high precision (as you can probably see)"
] | [
"Well, it might soon be the case that the SI units are defined in such as way that many of the important physical constants are of a fixed, exactly known value (similar to how the speed of light is currently defined). ",
"Here is a link",
" to the wikipedia page about it."
] |
[
"Is Gene editing possible on adult humans or can only be done on embryos ? Why ?"
] | [
false
] | null | [
"That’s a huge open question in biology right now, actually. We have a few methods of gene delivery that are being tried on a clinical level, of which the most developed one is AAV. There is also stuff like nanoparticle-based delivery, which is very promising but less far along clinically.",
"AAV is adeno-associa... | [
"I'm interested. Why, or rather, how, does a cell become immune to the virus after being \"infected\" by it?",
"What kind of far-fetched mechanism can you speculate could circumvent this immunity?"
] | [
"The cell itself doesn't become immune to virus, but your body will mount a strong immune response to the virus the next time it is encountered. That is what killed Jesse Gelsinger, the first recipient of virus vector gene therapy. I believe in that case the vector was was Adenovirus, not adeno-asociated virus, w... |
[
"If gravity is a property of spacetime, why are we trying to explain it as a fundamental force?"
] | [
false
] | I feel like I sound like a complete idiot asking this. I should mention I have no real background in physics, so I probably am an idiot. From what I understand, we describe the strong force, the weak force, and the electromagnetic force as fundamental forces of nature, with each force being mediated by their own boson ... | [
"the other three fundamental forces are gauge theories, meaning that they also admit a \"geometrical\" formulation similar to, but not equal, that for gravity given by general relativity.",
"There are immense similarities between the other three interactions and gravity. Moreover, the geometric picture and the fi... | [
"You can read general relativity entirely as a very complicated field theory on flat spacetime; you choose some particular coordinates and you treat the metric as just a tensor field with specific couplings to itself and to any other mass-energy. What you get is actually a gauge theory where the gauge symmetry aris... | [
"The fact that the other three fundamental forces are gauge theories being a tautology is possibly the greatest understatement I've heard this month."
] |
[
"If The Flash were real, would the friction between him and the air at certain speeds basically turn him into a big fireball?"
] | [
false
] | null | [
"If he's going fast enough, yeah! Not only that but sonic boom(s), wakes, and all sorts of atmospheric disturbances. ",
"This is all handled in the fiction by adding another layer of scifi/magic to account for all those problems:",
"\n",
"https://www.reddit.com/r/AskScienceFiction/comments/3ddjjx/dc\\_comics... | [
"One of the cool things about \"the boys\" on Amazon Video was that their \"flash\" killed someone by bursting them in a run by"
] | [
"The answer is yes, but the reasoning is actually interesting, in that it isn't really about friction. At a certain speed, it's not that he would be rubbing past the air which would cause him to heat up, it would be that the air would not be able to get out of the way in front of him, and it would therefore compres... |
[
"Does the colour of ink affect its properties?"
] | [
false
] | null | [
"Yes. Different colors of ink are the result of using different dye chemicals. Different chemicals » different properties.",
"Anecdotally, I used to do test engineering at a manufacturer of ",
"huge, continuous-production printers",
" and inks. We had to do lots of testing of new batches of ink, and the diffe... | [
"It's probably brand-specific, as ink manufacturers try to get uniform properties across all colors (though that might not be the case for pen mfr's).",
"If you were really curious, you could collect a large sample of ink of various colors and test the viscosity yourself using a flow cup viscometer. It's a pretty... | [
"I was wondering about viscosity in particular because it felt like all my red pens wrote smoother than my black pens. Is this inherent for red ink or is it just for that particular brand of ink? "
] |
[
"Why do different animals taste different?"
] | [
false
] | null | [
"Diet plays a huge part in determining taste, even within the same species. Grain fed vs grass fed beef for example. This diet causes the fatty acid profile to be slightly different and that accounts for the majority of the differences. Fatty acids can oxidize into a variety of aromatic compounds, some good, some v... | [
"Aside from diet, other things such as the activity of the animal, what temperature they live at and how ey adapt to it, distribution of fat and muscl (which is related to both activity and temperature) as well as more unexpected things at indirectly affect diet such as what type of internal flora the animal hosts ... | [
"Got it... Should have thought of that myself. :) Thanks!"
] |
[
"What are stitches that dissolve made out of, and how do they dissolve?"
] | [
false
] | [deleted] | [
"\"Dissolving stitches\" (absorbable sutures) are nowadays mostly made of particular biodegradable polyesters. They are chemically related, though not identical, to poly(lactic acid) or polylactide (abbreviated as PLA -- the most common \"compostable plastic\" and also a common material in 3D printing).",
"They d... | [
"your body identifies them as a foreign body and attacks them",
"Here I have to disagree. The dissolution is just a function of normal proteolytic degradation, normal protein turnover. You don't want the suture to trigger an immune response."
] | [
"your body identifies them as a foreign body and attacks them",
"Here I have to disagree. The dissolution is just a function of normal proteolytic degradation, normal protein turnover. You don't want the suture to trigger an immune response."
] |
[
"If water pressure is only increased with depth of water. Does that mean that you could have only 1 inch of water next to the Hoover dam from top to bottom and the stresses on the dam would be the same as a full reservoir?"
] | [
false
] | null | [
"Yes, if you build two dams back to back with only small gap between them and filled the gap with water the pressure would be the same as if there is whole lake behind the dam.",
"This is true as long as the gap is wide enough that water viskozity can be ignored."
] | [
"No the water upstream isn’t being forced on the dam. That’s what he’s explaining in the video. ",
"this",
" video also says the same thing. Pressure doesn’t increase with the shape of the container or reservoir. Being it miles long like the Colorado river or just a thin sheet being held next to the dam."
] | [
"Eh, yesish, but the water has to be held there somehow. This is done by the rest of the water in the resevoir. A 1 inch thick column of water needs some force to hold it in place, without that, it'd collapse. Making your dam wider or changing the dimensions of the reservoir would lower or raise the water height... |
[
"Acidosis and oxygen injections"
] | [
false
] | I ran across this which claims that an injection of an oxygen laden solution (sounds like an emulsion) could oxygenate blood without the need for breathing for 15-30 minutes during a life threatening situation. Many people are speculating on the possibilities of using this for diving purposes to eliminate the potential... | [
"I actually just answered a ",
"very similar question",
" to this one last night.",
"Essentially, you would get respiratory acidosis very quickly. Keep in mind that the technique is being used in a hospital on a sedentary/sedated patient so the oxygen needs for that individual are extremely low. The technique... | [
"A rough guide to the rise in pCO2 (partial pressure of CO2) is 6 mmHg for the first minute and 3 mmHg for each additional minute of apnea. So for 30 minutes of apnea: pCO2 = 40 (normal) + 6 + 29*3 = 133 mmHg, which is not compatible with life (at least, I have never seen someone survive that, it would put your pH... | [
"Just for the record, I've seen pcCO2's during arrest's on COPD'ers reach into the 150's. It's possible, but brutal to see, and they don't generally have good outcomes, because of what ends up happening to cerebral vasculature at the kind of acidosis/CO2 response."
] |
[
"If manure is all the waste from animals, why does it help fertilize soil?"
] | [
false
] | Always wondered how it could have any nutritional value to plants. | [
"Plants need Nitrogen, phosphorus, and potassium. Lucky for them, our shit contains lots of it."
] | [
"Nitrogen cycle?\nNitrogen cycle.",
"The nitrogen in manure is in the form of either ammonium or organic compounds like proteins, urea, etc. Decomposers convert the organic material into ammonium as a product of metabolism (Ammonification or Mineralization), while plants and microbes use ammonium to synthesize or... | [
"One mans trash is another plants treasure.",
"Same as we breathe in what plants effectively exhale and they breathe in our exhaled chemistry."
] |
[
"Question regarding the Multiverse theory."
] | [
false
] | Let's assume each possible universe is the same size and that no two universes are exactly the same. That makes the possibilities finite, correct? Not infinite? My thoughts are this: What this all means is that there is a universe out there where the only difference between ours and its is that one single atom, say, 3,... | [
"There is a finite number of ways to arrange matter and energy in a universe.",
"Why would this be finite? As far as we know, the universe is continuous, not discrete, which immediately leads to an infinite number of possible universes, even for a very simple system with one particle."
] | [
"There's a universe out there where Barack Obama is Spider-Man. And another universe where the only difference between that and it is that a blade of grass 2000 years ago swayed a millimeter further than it did in the other. Every different outcome of that universe exists just as every different outcome of any give... | [
"As in, can't the maximum possible information stored within a system be represented by the plank-area of a surface around that system?",
"We have no idea.",
"It's misleading to think of the Planck scale as the smallest possible scale or something like that. It's the scale where our understanding of physics bre... |
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