title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
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[
"So I just won ten dollars on a Reddit contest, which science charity should they send it to?"
] | [
false
] | I'm only eighteen, and I don't work, so I don't have a Paypal for the guy to give me my reward, so I'll ask him to donate it in my name. Any suggestions for a scientific-research charity? | [
"Second prize in a beauty contest?"
] | [
"I second this fund. Someone gifted me a donation in my name. Apparently they do some great things."
] | [
"I second this fund. Someone gifted me a donation in my name. Apparently they do some great things."
] |
[
"Why do all organisms want to pass on their genes?"
] | [
false
] | We know that the goal of an organism's life is to procreate and pass on their genes to their offspring to increase fitness, but is there a physical explanation as to why organisms feel the need to? (Sorry if this is horribly worded.) | [
"Because organisms that don't want to pass on their genes would die out. If all humans suddenly lost the urge to procreate, humanity would be gone in a century. Naturally, it's the surviving organisms that want to pass on their genes that pass on their genes."
] | [
"Just like mutations that aid in survival become dominant in a population, so do mutations that promote reproduction (because those that reproduce and pass down genes, produce the next generation). If an organism didn't feel the need to pass down their genes, their genetic makeup would end with that generation. "
] | [
"That actually makes more sense now. Thanks!"
] |
[
"Why do some vaccine injections cause more muscle soreness?"
] | [
false
] | In my personal experience, it seems that some shots make me more sore than others. For instance, I recently got my third Gardasil shot two days ago and my arm is still too sore to sleep on. In comparison, I've never felt discomfort after an annual flu shot. In general, why does this happen? I know that variables such a... | [
"This response is a little scattered with correct and incorrect bits weaved together. It's a little hard to break out so I will just try to be general:",
"Inflammation is a mechanism the immune system uses to attempt to ramp up a response to an infection/vaccination as well as attempt to directly clear the infec... | [
"Is there something inherent in certain vaccines that makes them more likely to cause muscle soreness than others?",
"Okay so this is the \"key question\" so I'd like to try to focus on addressing this. The short answer is \"yes\" but really, it's far more complicated than a simple yes or no. Inflammation from ... | [
"Correct me if I'm wrong but have you ever been sore after getting sick with something like the flu virus? I'm sure the soreness is your immune system inflaming to attack the vaccine. Inflammation causes lots of damage simply due to how it works inside of us. And so people with hyperactive immune systems asthma/all... |
[
"Is there any scientific explanation for Déjà vu?"
] | [
false
] | Is Déjà vu a chemical reaction in the brain or somehow related to foresight? I ask because I just had an intense bout of it where I was almost certain the same situation had happened previously. | [
"I don't think we know, but Daniel Dennett has ",
"a theory",
"."
] | [
"This question comes up all the time. ",
"Previous threads here",
"."
] | [
"Confirmation bias. 99% of the time, your dreams don't correlate with any later events, but the 1% of the time that they do, some people assume it's a \"vision\" or \"prediction\" of the future. ",
"In reality, it's just your brain recognising only the dreams that do later have some alignment with what eventually... |
[
"Why do we feel more 'emotional' when we are inebriated?"
] | [
false
] | null | [
"Alcohol impairs activity in the frontal lobe, which is responsible for higher order thinking such as judgment, reasoning, and sociality. Situations that seemed adverse before may no longer appear so, inhibitions are lowered, and the fine-tuned social and emotional cognition we possess becomes less fine-tuned."
] | [
"Yes and no. It will take away inhibitions. The part that tells you \"don't do that.\" or \"It is a bad idea to call your ex and tell her that you want her back.\" It isn't to say that it changes you as a person, but it can affect your view on what are acceptable and non acceptable actions.",
"I have heard people... | [
"Very helpful thanks! I actually never thought of the fact that alcohol is a CNS depressant. We are actually busy with the CNS right now in my bio class and specifically neuron firing and the effects of drugs so that's a neat bit more insight that I have there."
] |
[
"How do people get brain tumors if brain cells aren't actively dividing?"
] | [
false
] | From my understanding of biology, don't cells become cancerous after a mutation during mitosis? Why then do people get brain tumors if brain cells aren't actively going through mitosis? | [
"Brain tumors are generally caused by the small number of dividing cells in the brain -- the most common type of brain tumor is a ",
"glioma",
", which is a tumor derived from glial cells. Unlike neurons, glial cells keep dividing throughout life."
] | [
"While neurons them selves no longer divide, your brain is composed of multiple other cell types that DO still divide. The cell of interest for most tumors is the Glial cell which is sort of a support cell for neurons. It does things like take up excess neurotransmitter that is released by neurons, keep local pH at... | [
"Does \"glial cell\" refer to a particular cell type, or can it be applied to different kinds of non-neuron brain cells?"
] |
[
"How can we know what the composition of the Earth's core is?"
] | [
false
] | I am curios as to how we can define and to what degree of certainty do we know what the elements that compose the Earth's core are. | [
"We know the overall density of the Earth because we can observe how it interacts with other bodies (specifically, the Moon). We also know the size of Earth, so we can find it's mean density.",
"The density of samples of the crust and mantle can be measured.",
"By observing how seismic waves behave, we can det... | [
"Check out this link:",
"http://eqseis.geosc.psu.edu/~cammon/HTML/Classes/IntroQuakes/Notes/waves_and_interior.html",
"About 3/4 down, at P-Waves in Earth, it starts explaining the geometry of how \"shadows\" in P-waves and S-waves and the wavefront velocities reveal the locations of boundaries.",
"TL;DR: Bec... | [
"Very interesting.",
"By observing how seismic waves behave, we can determine the size of the core",
"Can you provide more details about this?"
] |
[
"Has the invention of the light bulb lead to any measurable evolutionary changes among moths or other night light-obsessed insects?"
] | [
false
] | Full disclosure this was inspired by | [
"There does indeed seem to be some research to support this idea! ",
"Altermatt and Ebert 2016",
" conducted a study on ",
"spindle ermine moths",
" to address the question of how light pollution has affected insects. They collected larvae from 10 regions with either high or low light pollution, and raise... | [
"Fair question! The most commonly given explanation I've seen is that moths use celestial objects (such as the moon) as landmarks for navigational purposes, and get confused since artificial lights can easily be as bright or brighter. This reasoning seems to be favoured by Mike Saunders at Penn State (",
"sourc... | [
"What’s the benefit in moths being attracted to light, pre electricity?"
] |
[
"What is the difference between hydrogen and anti hydrogen?"
] | [
false
] | How do they vary chemically? Can I drink anti water without it affecting me? | [
"Anti-hydrogen is made of an anti-proton and a positron instead of a proton and an electron. If you drank anti-water it would annihilate with the regular matter in your face and, as Randall Monroe puts it \"you would obviously die pretty quickly. You wouldn't really die of anything, in the traditional sense. You wo... | [
"In your mouth"
] | [
"Using E=mc",
" we get 1.8*10",
" joules for 1g of antimatter annihilating with 1g of matter. That's about 43 kilo tons tnt equivalent."
] |
[
"What are the low level computational operations necessary to perform 1 + 1, or other whole number additions?"
] | [
false
] | Assuming you have as much memory space as you need, what does the series of steps boil down to logically to perform this operation on a theoretical computer? I'm guessing there are many ways to do this, but is there a method with the provably least amount of steps that is also capable of arbitrary whole number addition... | [
"Whole number addition in computers is taken care of by a circuit known as an ",
"Adder",
". Adders are relatively simple, and come in two types: a half adder, and a full adder.",
"Let's start with a half-adder. The form with the fewest number of logic gates is:",
"S = A ⊕ B\nC = A ∧ B\n",
"This half a... | [
"To tack on a bit (no pun intended). This is implented in hardware in the processor with a subsystem called an Arithmetic Logic Unit (ALU). ",
"What I mean by that is an N bit adder is implemented by building N full adder stages where the Nth stage is fed by the output bit and carry bit of the N-1th stage, which ... | [
"It's pretty easy to prove that the half-adder is as efficient as it can possibly be. It's only two logic gates. To be any more efficient, you'd need to be able to do it in a single gate. We know all of the possible gates, so all it requires is seeing that none of them can generate the truth table for the two-ga... |
[
"Do car windscreens absorb a significant amount of UV radiation?"
] | [
false
] | [deleted] | [
"Side windows are usually plastic and will block UVA but not B.",
"In the US at least side windows are almost always tempered glass. The only exception I can think of is cars with a soft cloth top."
] | [
"Side windows are usually plastic and will block UVA but not B.",
"In the US at least side windows are almost always tempered glass. The only exception I can think of is cars with a soft cloth top."
] | [
"Car windshields are typically made from soda-lime based glass, with a plastic (",
"EVA",
", for example) intermediate layer. Soda-lime glass blocks a ",
"pretty good chunk",
" of the ultraviolet spectrum. However, as you can see, the absorption is not quite 100% - and it's a little bit more effective in ... |
[
"AskScience: Can anyone recommend an insightful intro to Quantum Physics book geared for a social scientist?"
] | [
false
] | Consider me fairly well rounded in statistics and methodology. Most of my work has been focused on cognitive correlates of interpersonal trauma. I'm trying to foster an interest in topics outside of my discipline. I feel sheepish to ask for a recommendation regarding the topic: I know a good deal of woo is produced whe... | [
"What you want to do is find a book on 'Modern physics'. These will be largely devoted to introductory quantum mechanics, and probably only assume that you've had a basic mechanics and a basic E&M course."
] | [
"E.g. Serway Moses and Moyer."
] | [
"I really loved QED by Feynman and I'm not a physicist, though I love physics with a passion. The book is fantastic in that you need very little math to enjoy the story. And Feynman is world renowned for his story telling abilities."
] |
[
"Are all prime numbers smaller than the biggest prime number discovered?"
] | [
false
] | The record of the biggest prime number is for 2 and was discovered using GIMPS. I want to know if all the smaller prime numbers are discovered, or if are there missing numbers. | [
"There are definitely much smaller primes that we don't know about. The first \"gaps\" in our list of primes are ",
" smaller than that, and probably a lot smaller than you might guess. The reason for this is simple: there are just ",
" primes, it's impossible to list them all out.",
"Imagine you wanted to ma... | [
"There are certainly smaller primes that have not been discovered. Mersenne Primes (the primes that GIMPS finds) are a very special case of primes that follow a specific rule (a factor of 2",
" -1) - but not all primes (big or small) follow this rule. ",
"There are known non-Mersenne Primes amongst the ten l... | [
"You can store the primes much more efficiently. You don't have to store every single bit of its binary representation, it is sufficient to store e.g. the difference to the previous prime plus absolute numbers once in a while. And you don't have to store the last bit ever because it is always 1 (apart from the firs... |
[
"Which way should a fan face to get more fresh air into a room?"
] | [
false
] | I live in a studio apartment with only one window. If I want to increase ventilation and the amount of fresh air, which direction should the fan face? I've heard arguments for both into the apartment and towards the window, can anybody help? Bonus meme: I have a vent in my bathroom, would permanently keeping this on im... | [
"Keeping the vent on in your bathroom, and placing the fan infront or in your window to blow fresh air into the apartment will provide maximum fresh air replenishment. The bathroom will be venting stale air from inside your apartment to the outdoors, while the fan will be sucking fresh air from outside and blowing ... | [
"I'll just add another option. Instead of blowing air out or sucking air in, another option is to blow air parallel to the window, the idea being that turbulence with the window will bring in fresh air while also circulating that air into the room."
] | [
"Understood and appreciated. Thank you very much! "
] |
[
"What is the next likely leap forward in computing?"
] | [
false
] | I have heard that computers are reaching their a physical constraint in how fast they go so what is are the potential technologies for the next big breakthrough? I am computer illiterate but have heard about quantum computers, and other potential technologies involving bioligical elements... How far away are we from re... | [
"The physical constraints have more or less pretty much been encountered as you said. ",
"Not that this is what you asked, but the nature of the problem is that the circuitry making up CPUs has gotten so small that the \"wires\" and \"rubber/insulator\" that consitute the circuit are each no thicker than a few ... | [
"\"next likely leap\"",
"Many many processor cores in a single chip.",
"Recently 1 core was the only affordable option; and highly parallel chips were rather inflexible and could only do one thing well (say, GPUs, or hardware video chips), or were extremely hard to program (DSPs with odd-sized registers and tr... | [
"Also, if I understand correctly, the electron acts as a wave, a higher energy results in a larger wave length and the size of this wave length is what limits the distance to the nucleus. Therefore it isn't the the electrons \"Magically\" jump to a new location without traveling in between but rather the wave bec... |
[
"So, the Oort Cloud... Is there any hard evidence?"
] | [
false
] | Every time I read something about comets they always mention the Oort Cloud. Looking into the subject, I can never find anything about it that doesn't seem like speculation. Yes, they seem to be very well thought out theories, but nothing seems to imply any hard evidence to its existence. It seems like an awful lot o... | [
"Well, when we look at comets, we find many comets that are long term periodic comets. These comets take thousands of years to orbit and go very far out beyond what we conventionally think of as our solar system. However, they are still a 'part' of our solar system as they're gravitationally bound to the sun.",
"... | [
"At this point, the idea of the Oort Cloud fits the facts, and is the simplest explanation that we have that fits the facts.",
"- If we discover that this idea doesn't really fit the facts, or if we come up with a simpler explanation that fits the facts, then we'll use ",
" explanation instead. ",
"http://e... | [
"But what facts? Other than just seeing long- period comets, what about them leads to these conclusions? Every other sentence in the Wikipedia article starts with, \"it is believed...\" or \"scientists think...\" and other vague language. As far as I can tell, and admittedly I'm no astrophysicist, what's to say... |
[
"Why do some animals (like certain reptiles) grow until death while others stop growing fairly early in life?"
] | [
false
] | [deleted] | [
"This isn't my area, but here goes:",
"Think of a housecat and a lion. Both require pretty much the same kind of diet, the lion just needs a lot ",
" Why? Because the lion is much bigger, it burns more energy just walking around and existing. This is referred to as the basal metabolic rate (BMR), and is literal... | [
"The gist is that it would be evolutionary suicide for warm blooded animals to keep growing- getting enough food to keep up with their energy requirements would be an enormous challenge. So they were probably selected against this when they diverged from reptiles. Reptiles don't care- constantly increasing size mea... | [
"The gist is that it would be evolutionary suicide for warm blooded animals to keep growing- getting enough food to keep up with their energy requirements would be an enormous challenge. So they were probably selected against this when they diverged from reptiles. Reptiles don't care- constantly increasing size mea... |
[
"I'm not sure where to ask this but: what are some theories that were widely accepted by the scientific comunity but have since been proven false?"
] | [
false
] | null | [
"I forgot to add that they had to be proved under what we today would call rigorous testing of some sort. Not necessarily intense but at least following the scientific method. I think these examples are more things people would infer because they seemed obvious."
] | [
"Caloric theory",
" was a remarkably successful and fairly long lived but mostly wrong theory of heat.",
"I think geocentric theory is a decent candidate as well. It might have been the obvious inference, but the theory was carefully thought out, was and is capable of very accurate astronomic predictions, and o... | [
"Thanks. Geocentric theory is close to what I was looking for."
] |
[
"Is there any reason Death Valley happens to be both one of the lowest and hottest points on earth, or is this just a coincidence?"
] | [
false
] | null | [
"Okay important:",
"It ",
" the hottest. In summer, it has record high temperatures. In winter, even the nearby Sonoran desert will be warmer than Death Valley.",
"The high temperature is due to a combination of the low elevation (higher atmospheric pressure) and extremely dry conditions allowing for high ins... | [
"Hello, friendly neighborhood geologist here. Death Valley never has been a sea. Its so low because its an example of a pull-apart basin. It happens to be caught between two fault zones that have a bend in them and as they slip, the part in the middle gets dropped down. Since the inception of the faults responsible... | [
"Hello, friendly neighborhood geologist here. Death Valley never has been a sea. Its so low because its an example of a pull-apart basin. It happens to be caught between two fault zones that have a bend in them and as they slip, the part in the middle gets dropped down. Since the inception of the faults responsible... |
[
"How were steam tables generated experimentally?"
] | [
false
] | Specifically, how were properties of water/steam like internal energy, enthalpy, and entropy determined (or confirmed) experimentally? | [
"Enthalpy, entropy and internal energy are derived from first principles using the laws of thermodynamics and the definition of these terms.",
"The constants in each case for example the specifix heat capacity is determined experimentally. Using the equations and imperial data you get the desired value.",
"Am I... | [
"Some of the experimental methods are covered in ",
"Tables of the Properties of Saturated Steam and Other Vapors",
"."
] | [
"Yes please"
] |
[
"How is toothpaste sweet and 'good' for our teeth?"
] | [
false
] | [deleted] | [
"Toothpaste uses non-cariogenic sweeteners (usually xylitol or other sugar alcohols) to provide a sweet taste without contributing to tooth decay, even if you were to smear it on your teeth and leave it there."
] | [
"Toothpaste, above all over reasons, is an abrasive that is easily washed away after application.",
"The toothpaste is just there to help clean gunk and buildup off your teeth and just under/around the surface of your gums. By removing these off the surface, you stop tooth decay. Toothpaste also has a few ingredi... | [
"you do not want to leave you teeth exposed to those for any significant amount of time. You will end up with spots on your teeth."
] |
[
"Does gravitational time dilation cause Mercury to travel through time slower than Earth?"
] | [
false
] | Mercury is close enough to the sun to experience relativity effects. Gravitational time dilation is a phenomenon of General Relativity where time passes more slowly for something close to a source of gravity, compare to something more distant from that source of gravity. Does it follow that Mercury is travelling throug... | [
"Yes. The equation for gravitational time dilation is ",
"To = Tf(sqrt(1-2GM/(rc",
" ). To is time viewed from mercury, and Tf is time viewed from outside of the gravitational field. ",
"So therefore 1 hour to an outside observer is equal to (3600sqrt(1-2G(1.989E30 )/(5.7909E10 c",
" ))=3599.99991 seconds o... | [
"what's the follow-up question?"
] | [
"Would time dilation have an effect on how a star ages from our frame of reference?",
"Do the nuclear reactions in the core happen significantly slower than a similar nuclear reaction on earth?",
"Does a massive star age slower than a smaller star due to time dilation?"
] |
[
"Why is the Milky Way a [barred] spiral galaxy?"
] | [
false
] | I know that galaxies are created in a process having something to do with lots of dust coming together in one way or another to form stars. It seems, though, that such a collection of dust and gas would tend to form a blob, perhaps in the same manner as a very large dust bunny. asked this question, but didn't receive a... | [
"It seems, though, that such a collection of dust and gas would tend to form a blob, perhaps in the same manner as a very large dust bunny.",
"The thing is that gas is collisional, so it won't remain in a diffuse blob indefinitely-- it will collapse, and as it collapses, it will pick up rotation, and as it rotate... | [
"The simplest answer to this question is: energy. Any system must conserve angular momentum, but \"wants\" to get to a low energy state, by dissipating the energy into heat. The the case of orbital systems, the way to do this is put as much angular momentum momentum in the smallest amount of matter, thus shoving th... | [
"I'll break your question up a bit.",
"So, imagine we start as a big blob of gas. These gas particles have all sorts of large random velocities, and these big velocities keep them in orbit around the centre-of-mass of the big blob of gas.",
"Now, these gas particles have all sorts of velocities, so they're goin... |
[
"Why are different brain structures associated with different functions?"
] | [
false
] | I’m starting my PhD in clinical psychology studying neuropsychology this fall and I’ve been getting interested in learning some functional neuroanatomy before I begin. One thing I’ve found particularly difficult to wrap my head around is the functions of brain structures in relation to each other, something I know is n... | [
"Is it something unique to its place in the brain, it’s connections, or it’s unique physiology?",
"All three.",
"its place in the brain",
"The brain was built up piece by piece over the course of evolution, and the oldest structures are typically involved in basic physiological processes, such as the regulati... | [
"Since no one else has offered an answer yet, here's my take on it.",
"Speaking generically: A structure in the brain functions the way it does according to 3 main criteria.",
"Regarding the location of different structures, that appears to be mainly related to how far back they evolved. Like the basic functi... | [
"Or broca and wernicke’s areas, WHY do they perform their unique functions in speech? Again is there something about the unique connectivity between brain regions that allows for this specificity of function or is it something else?",
"Wernicke's is right around the primary and secondary auditory cortex, where yo... |
[
"Why does increasing the brightness of your phone while it is in the sun make it easier to see since it is already very bright outside?"
] | [
false
] | null | [
"What you see is determined by what light enters your eyes (duh). If the light of the sun is brighter than the light of your phone, you'll only see reflected sunlight from your phone. If you turn up the brightness on your phone, its light will be brighter than the reflected sunlight, and you will see your screen."
... | [
"The issue is contrast. Phone screens are usually light-emitting. Shining light on them lightens the black, but doesn't brighten the colors, so the the black-to-color contrast is reduced.",
"There are also rare \"electronic paper\" or Mirasol (IMOD) microelectromechanical screens that are not light-emitting, but ... | [
"Your eyes work over an amazing range of lighting conditions by varying the size of your pupil to control the amount of light entering the eye. It's an amazingly broad range... from tiny amounts of light reflected from the moon (less than millionths of candellas per square meter), to the brightest sunniest days (mo... |
[
"Do synthetic neurotransmitters exist?"
] | [
false
] | And if they are why don't you hear more about them being used as treatment? For example if Alzheimer's is caused (or can be caused) by a lack of acetylcholine, would it be feasible to make a synthetic in order to treat it? | [
"You have you to remember that neurotransmitters are just soluable signalling molecules. Serotonin, for instance, can be easily classified as a hormone. Estrogen is a steroid. I think if you adjust your concept of what defines a signalling molecule, you'll find that many drugs are in fact \"synthetic\" neurotransmi... | [
"its never usually as simple as 'we just need more neurotransmitters'",
"some examples though, not cures but they are helpful:",
"l-dopa for parkinsons which gets converted to dopamine",
"acetylcholine precursors for alz(cdp-choline, alpha-gpc)",
"mao-b inhibitors slow down the body from breaking down dopam... | [
"There's no need to synthesize artificial ones as we can actually synthesize the real thing. For example, common neurotransmitters, like glutamate and acetylcholine, are easily available from the chemical company Sigma-Aldrich. They have modified variants of these transmitters too, but no one calls them \"artificia... |
[
"When research shows some people share 2-4% of their DNA with Neanderthals, what DNA are they talking about?"
] | [
false
] | I read in an article recently that some people share 2-4% of their DNA with Neanderthals. However, we also share loads of DNA (>95% IIRC) with less similar species such as Chimpanzees. So, when we say we share 2-4% of DNA with Neanderthals, is that only some part of our DNA that is measured separately, like repetitive ... | [
"Here's a simple analogy. Suppose almost everyone in your family was Icelandic, except that one of your great-grandparents was Nigerian. Your DNA would be 87.5% Icelandic, 12.5% Nigerian. ",
". However, those populations have accumulated mutations that make parts of their DNA distinct. So when someone says you ar... | [
"Aah, so it's kinda like how we share \"50%\" of DNA with either parent even though a lot of the DNA is the same, it's just that certain DNA that makes us different from one another is 50% from either parent?"
] | [
"Yes, more or less. You're much more than 50% identical to either parent, in terms of sequence content. But roughly half of your DNA will be inherited from each and will be characterized by SNVs (as well as other variants) associated with that particular parent."
] |
[
"Why is a detached, insulated but non-heated garage warmer than outside during winter?"
] | [
false
] | [deleted] | [
"There could be tons of factors influencing this. Firstly, even if completely insulated (and ignoring the sun) you should expect the temp to average out to the same daily average as outside, but with smaller extremes. This means if you have a high of +5C during the day and low of -25C at night you would maybe ex... | [
"if completely insulated (and ignoring the sun) you should expect the temp to average out to the same daily average as outside, but with smaller extremes.",
"If completely insulated, the temp will be the ",
" average.",
"This is the famous Wine Cellar problem, a pretty popular partial differential form in the... | [
"I would imagine the ground would be not much less than 0C if the air temp is not consistently under 0C for less than 2 months (canadian intuition)."
] |
[
"Do metal bonds make pure chemical compounds or mixtures?"
] | [
false
] | Say bronze, witch is an alloy between tin and copper. Is bronze then a mixture like chocolate is a mixture or is it a pure compound like salt or CO. | [
"I'm not sure how in-depth a response you want, but:",
"Things like bronze are a mixture of pure elements, at least one being a metal. As the materials don't bond together to make a compound, alloys are really much closer to a mixture. (Although producing an alloy of two metals can produce vastly different physic... | [
"Bronze is a mixture. It's not possible to have a single molecule of bronze (as it is for CO). There is no crystal structure for bronze (as there is for salt). However, the tin and copper atoms are bonded to each other by metallic bonding."
] | [
"would for example an iron bar be one really big molecule with just lots of iron atoms in it or something else? "
] |
[
"Is it possible to determine the composition of a new molecule using spectroscopy?"
] | [
false
] | [deleted] | [
"Theoretically I think you could determine the spectrum of a molecule based on physics, though this would be incredibly difficult. I don't think this works the other way around though, ie determining the molecule by the spectrum.",
"It would be more likely that we could just compare it to known molecules and look... | [
"There are efforts to identify the specific chemical formulas of the Polycyclic Aromatic Hydrocarbons that are identified in molecular clouds in space from their spectral lines."
] | [
"In principle, it's not out of the realm of possibility. Practically speaking, astrochemistry has both observational and laboratory components. Being able to pin down unique spectral signatures in the laboratory benefits future observational efforts. "
] |
[
"What is the purpose of LPS-stimulated cytokine release?"
] | [
false
] | I'm curious as to what specific research questions are satisfied with LPS-stimulated cytokine release through use of whole blood, as opposed to running high sensitivity ELISA kits on blood plasma. | [
"It's usually just a gross measure of activation. It can tell you how many monocytes or dendritic cells are present (they are some of the primary cells expressing the receptor for LPS; TLR4) but also how the cells are communicating. For example, LPS will stimulate IL-12 production which can promote T or NK cell exp... | [
"The questions are different-- LPS would tell you how the cells in blood are responding to an inflammatory stimulus, whole blood plasma would tell you what has already been produced and is floating around in the blood. Depends on the question you want to ask. Based on your interest in the inflammatory response I'd ... | [
"Thanks for the informative response!",
"What about the distinction between LPS stimulated cytokine release vs your typical high sensitivity ELISA via plasma? Is there a clear demarcation as to when one is indicated vs the other? I'm basically looking into a project that would assess an individual's inflammatory ... |
[
"Why is it that when sleeping, we can regulate our temperature by having one foot in or out of the duvet?"
] | [
false
] | When I get hot at night, if I leave one foot out of the duvet I feel as if my temperature is much more comfortable, likewise if I'm cold I'll pull it in. Generally I'll always sleep with one foot out however, it seems 'optimal'. I know many other people do this and experience this too, so what's the science behind it -... | [
"Under a heavy blanket that allows little heat to escape, one can feel overheated because we are constantly producing heat as a byproduct of reactions going on in our cells. Leaving one foot out of the duvet allows heat to escape. ",
"Thermoregulation mechanisms include the rerouting of blood flow to superficial ... | [
"Yes, but to a lesser extent. Humans experience greater heat loss per unit surface area from their feet than from hands. This has been attributed to vasoconstrictor tone of vessels in the leg, different vascularization between the hands and feet, and morphological differences (size, shape, insulation etc.). This pa... | [
"Awesome explanation, thanks. So potentially the same effect could be had by sticking an arm out perhaps?"
] |
[
"Timeline of a viral infection of one cell?"
] | [
false
] | As I understand, a virus spike protein latches to the cell receptor. The viral RNA (or DNA, not sure) gets inside and starts instructing the cell to produce more viruse copies. Eventually, the cell bursts and releases the virus copies. My question is how long does each step take? Is it super quick like 10 seconds or su... | [
"Different families of viruses have different proteins and different mechanisms of infection; you’re correct that coronaviruses have a spike protein on their surface to attach to a host receptor. Viruses can have DNA and/or RNA, also dependent on the virus. Answering your question, the replication timeline also var... | [
"This is a great question and one I actually had to do a bit of research on.",
"At least for adenoviruses, it varies cell to cell--time from when the virus contacts the cell to when it starts replicating ranged from 10 minutes to 4 hours in ",
"this experiment",
". From then, there was another hour or two fro... | [
"It depends on both the virus and the cell but in general in on the scale of hours. Different viruses go about this differently too. For example Herpes viruses (like HSV or chickenpox) might infect a nerve cell and do nothing for decades before becoming active again while Norovirus might bud off a cell a few hours ... |
[
"Do NSAIDs help soft tissue injuries heal?"
] | [
false
] | A medical student that I know was the opinion that NSAIDs should be taken in the case of soft tissue injuries and that these help them to heal faster. If I look this up, most of the advice available on the internetz is actually to the contrary - inflammation is necessary for injuries to heal, and anti-inflammatories ca... | [
"Top answer is misinformed. First and foremost, nsaids are not linked to injury through swelling by “bleeding.” when nsaids are linked to greater injury the mechanisms are super complicated because inflammation is super complicated. It typically involves misbehavior of specific group of cells, not bleeding. ",
"... | [
"I'm a doctor and just want to reinforce what you said here. This is the best answer. I think it's a VERY important point that, for most injuries, encouraging early mobility is a huge part of healing. In general, less pain and swelling leads to more movement which leads to enhanced healing. All else being equal, NS... | [
"They CAN help under certain situations. During the acute phase of the injury they can actually do some damage by increasing bleeding/swelling. This is why anytime someone is going in for a surgery or procedure the doctors want you off of NSAIDS. ",
"But they can help in the chronic phase of injury by reducing pa... |
[
"Would an 'alien' have the same senses we do?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"For more information regarding this and similar issues, please see our ",
"guidelines.",
"If you disagree with this decision, please send a message to the moderators."
] | [
"You say this is speculative but it's not. Well a little. But I just want to know if you need all 5 senses that we have to have a super-being like humans, or if others can be used or less. Do you know of a better way to word this?"
] | [
"I don't know what you mean by superbeing. We have way more than 5 senses. Nonhuman animals have plenty of senses that we don't like echolocation, sensitivity to magnetic fields, sensitivity to electrical currents, etc."
] |
[
"Why do some people have higher body temperature than others? (I think my SO is the Human Torch)"
] | [
false
] | Is my girlfriend secretly a member of the Fantastic Four? My girlfriend and I (I'm a girl too) are almost the same height and weight, have similar diet (but she exercises much more than I do) and yet she burns up in the middle of the night enough to wake me up (and I'm a heavy sleeper!). She isn't sick or anything, bec... | [
"Thyroid disorders and diabetes can affect body temperature. The Fahrenheit scale was supposed to have been defined such that 100ºF was body temperature, but Dr. Fahrenheit picked a bad subject for calibration."
] | [
"I would like to know more about this as well. My normal temperature is about .6 degrees above the average. Girls I've been with have definitely noticed that I can heat a football stadium while in a coma."
] | [
"[[citation needed]]"
] |
[
"How does the SARS 2 virus infect a cell via ACE2?"
] | [
false
] | This is something I've been wondering about for a while, ever since almost the beginning of this pandemic, actually. ACE2, as the name implies, is an ngiotensin onverting nzyme. Its purpose appears to be that it sits on (or well, in, but one part sticks out above and one below) the cell membrane so that when molecules ... | [
"It binds with the ACE2 receptor to enter the host cell. The S protein is primed by serine protease TMPRSS2, which release the S protein subunit S2 to fuse the viral and cellular membrane. Then the viral genes enter into the cell and reproduce more viruses (",
"source",
")."
] | [
"I actually did not know that. I would add then that binding to a surface protein can correctly position another entry method since binding to the protein fixes the orientation and position relative to the target cell, allowing a built in transport mechanism to do its thing.",
"I actually never delved too far int... | [
"The simplest way to address this topic is to tale about a more commonly targeted receptor: glucose. Every cell needs glucose, so if a virus needs bait to get into the cell, they can attach a glucose molecule to a stick and when the cell goes to bring in the glucose the virus comes with it. Sugars are commonly avai... |
[
"How big can a cube get before gravity would collapse it into a sphere?"
] | [
false
] | null | [
"If you look at asteroids. After a few miles across they start to appear more and more spherical. But i think your question depends on the rigidity and density of the cube. That I can’t answer but my guess is a hundred or so miles across before bending or collapsing into more sphere like. "
] | [
"This depends on the composition of the object. What you're asking is about ",
"hydrostatic equilibrium",
". If the cube was made of ice, a diameter of 400km or so seems to be the lower limit. Ice needs less mass to reach hydrostatic equilibrium than rock. For example, the icy Saturnian moon Mimas has an equili... | [
"But Iapetus is 80% ice so you'd think it would be in equilibrium too?"
] |
[
"How reliable is the act of testing/comparing isotope fingerprints in a living organism against those fingerprints in lead in ammunition?"
] | [
false
] | one of the quotes from the article: In a study led by Finklestein’s team at UC Santa Cruz, the source of the lead poisoning was traced back to ammunition via isotope testing. Whereas captive condors have lead isotope “fingerprints” which match that of background environmental lead in California, the wild condors have b... | [
"The problem with this study is that they did not test other environmental factors that may cause lead exposure. In effect, they skewed the study for a political agenda...",
"See the post here made by indgosky",
"Plain and Simple -- It is a Propaganda Piece",
"Hunting with lead over water has been banned in ... | [
"Until someone else answers you, I'll offer what I found.",
"Determination of isotopes is very well understood. It is how radiocarbon dating works.",
"I do not know how lead melted down for ammunition would differ from any other form. [",
"http://en.wikipedia.org/wiki/Lead#Isotopes](Wikipedia)",
" says th... | [
"This article has slightly more of the science: ",
"http://www.biologicaldiversity.org/species/birds/California_condor/pdfs/Condor-Lead-Science.pdf",
"In short:",
"Isotopic analysis of lead in the blood of pre-release and free-flying condors in California \nstrongly supports the link between lead ammunition a... |
[
"How is shocked quartz considered evidence of mass extinctions?"
] | [
false
] | The Permian-Triassic extinction is what I have in mind here. According to what I've found from google searching this extinction event, shocked quartz discovered in Australia and Antarctica are huge indicators that it was caused by a meteor impact. How are deformed rocks that indicative of something like this? Is ther... | [
"A couple of things:",
"The Permo-Triassic extinction is a fact, we do not need shocked quartz to postulate it's existance. We lost in excess of 90% of marine species at that time (source 1: (",
"https://194.44.198.33/faculty/geology/phis_geo/fourman/library-Earth/New-library/How%20to%20kill%20(almost)%20all%20... | [
"It's worth adding that one of the other principal candidates for a cause for the P/Tr extinction is the eruption of the Siberian Traps through large deposits of carbonate. The PNAS paper that ",
"/u/Gargatua13013",
" linked to as a review of biodiversity collapse is critical of this hypothesis (or at least cri... | [
"There is a lot of sourced data in the reply I gave, you may have a look at the first 3 sources which are general papers on the event.",
"The evidence we have for the extinction event comes from counting the species on either side of the PT-boundary. We see through direct observation a loss of in excess of 90% of... |
[
"Is salt sterile?"
] | [
false
] | All I know is that salt has a way of drying out and preserving things from bacteria and the like. So, is the surface of salt itself free of any bacteria? | [
"I'm sure the surface of salt is devoid of free-living bacteria, but there are many other forms of life to consider when thinking of sterility. Spores, viruses, prions, etc... could all live on the surface of a salt crystal."
] | [
"You are correct in your assessment of life, but it should be noted that sterilization is more broadly defined than that. To offer a more thorough explanation for anyone who might not understand. ",
"Life is defined in biology as anything which satisfies most or all of the these states:",
"Homeostasis: Regula... | [
"As I have said previously, your perspective is a valid one and viruses straddle the edge of what is life and what is not. It was ultimately decided that they are not alive and nobody here has the authority or means to change that definition. It is simply a definition though, and it changes nothing in regards to ... |
[
"Could the universe be full of intelligent life but the closest civilization to us is just too far away to see?"
] | [
false
] | null | [
"Thousands of years ahead? Try billions of years.",
"A solar system capable of supporting life needs to be formed from the material from a dead star. Most stars last for several billion years, but really massive stars can have lifespans of only a few million years. The universe had 9 billion years to develop befo... | [
"There's no reason a species of our technology level could not have existed 5 billion years ago",
"I guess academically I knew this, but seeing it explicitly written and then considering it is overwhelming."
] | [
"I think if you haven't managed intergalactic colonization and domination after 5 billion years it's safe to say your species hasn't really been trying."
] |
[
"Is storing nuclear waste substantially more dangerous from storing mercury?"
] | [
false
] | null | [
"Nuclear waste is much more dangerous than elemental mercury. That being said, yes, people are very ignorant and overly afraid of nuclear waste storage."
] | [
"Nuclear waste is much more dangerous than elemental mercury.",
"How do you quantify that? As a totally uninformed guess, I would think that more health damage is being done by mercury than by nuclear waste, if you sum it up.",
"Also, nuclear waste has the nice property that you can detect it trivially with a G... | [
"Why would you think that? What is that assumption based on?",
"Nuclear waste is a highly radioactive cocktail of many elements and compounds, some of which are very toxic to humans."
] |
[
"Do protons and neutrons also have probability clouds?"
] | [
false
] | And any other particle for that matter | [
"There's uncertainty in position and momentum for all particles, so yes. My modern physics professor had an assignment where you calculate the uncertainty in position of a Buick. It's just that the probability cloud for a Buick is so small that it's silly to even think about."
] | [
"So basically it's a normal physics question."
] | [
"It's one of those ridiculous exponential answers, where the answer is so large (or in this case, small) that it outnumbers the atoms in the universe."
] |
[
"Is it more economical to fly against the rotation of the earth on its axis?"
] | [
false
] | Let's say you're in the middle of USA and you want to fly exactly to the other side of the earth. Would it take less gas flying against the rotation of the earth? Why/why not? I can't seem to wrap my head around this topic. | [
"You might be thinking that you would have to fly less if the Earth was moving underneath you while you are flying towards a location, and that thought is correct: when planning flight routes airlines take into account the rotation of the Earth.",
"For most practical reasons though, the effect is completely negat... | [
"Thank you for the explanation. :)"
] | [
"I want to understand the first part, having to do with rotation. Since the plane starts with the same velocity of the Earth, how could rotation make a difference?",
"If I'm on top of a train going 20 mph and leap forward five feet, then jump with the same strength in the other direction, wouldn't I go five feet... |
[
"Why do bubbles form on the walls of a water bottle when you first fill it up?"
] | [
false
] | When I fill up my water bottle, there's a ton of bubbles and they all seem to stick to the walls of the water bottle. I assume they are air that is trapped as the water is being poured, and they eventually dissipate. Why are they so attracted to the wals of the water bottle though? Thanks! | [
"They form around ",
"nucleation sites",
". ",
"There was a show about that reaction you get from adding Mentos to Coke (Mythbusters? I can't remember) explaining it quite nicely."
] | [
"The plastic bottle isn't perfectly smooth. There are microscopic pockets of air along the walls of the bottle. As bubbles form, they attract each other, Sort of like watching water roll down the window on a rainy day. So the question isn't necessarily why the are attracted to the walls, but what keeps the air in ... | [
"What kind of water are you talking about? tap water drinking distilled? \nTap water has carbonic acid, that is just CO2 that is dissolved in the water. If you de-gas the water there may be less bubbles. The porous inside of your water bottle (presumably plastic) is allowing the dissolved gasses to attach to the wa... |
[
"Why does the chloralkali process with graphite anodes create furans (dioxin-like)?"
] | [
false
] | Are dioxin like furans (PCDF) formed if saltwater comes in contact with electricity and steel like in a phone charger or computer port? Are they formed in school experiments with electrolysis of brine? | [
"I’m a Chemical Engineer with years of chlorine and reactive metal experience. ",
"In general, chlorine being formed at the graphite anode corrodes the anode. The corrosion products are “chlorocarbons”. The most abundant product is carbon tetrachloride. ",
"The whole range of saturated chlorocarbons is formed... | [
"Thanks. Will any chlorine, carbon and anode combo make furans though? Is there something unique about the graphite, like the aromatic structure, required for PAH and then PCDF formation?"
] | [
"Most of my work was in the 400-1000 C range. Any water was interstitial water in the salt crystal. I never found Furans. Did make a bunch of phosgene. But furans are pretty volatile and flammable. ",
"Carbon tetrachloride was in the 50 ppm range. Aromatics were primarily hexachlorobenzene (ppb levels). Roughly... |
[
"how can you tell direction in outer space?"
] | [
false
] | I was just thinking about how if youre on earth you can head in one direction and end up back where you started. also our compass only has 2-axis. if you were in outer space you'd have a lot more possiblities for direction. Say you have a friend on mars, how the hell do you give them directions back to earth (keep in m... | [
"You need to establish a coordinate system. When you talk with your frind on mars about directions, it would be a good idea to take the sun as the center of a ",
"spherical coordinate system",
". Then you can tell him to fly towards a point in that coordinate system."
] | [
"This is the best answer I have read so far:",
"There's nothing special about directions in space as such (maybe if you get into general relativity but I don't suppose you meant that). Mars is right in the direction where it seems to be. What I think you're asking is how the orbits work. That is, if you are on th... | [
"It sounds to me like you know better (\"a lot of wasted energy\")... ",
"For the OP's sake, and anyone else wondering... No. It isn't a straight shot. When you leave one planet you orbit around the Sun. So your path to get from one planet to another involves you working your way around the Sun. On top of that, t... |
[
"How vaccines work, specifically why do we need boosters?"
] | [
false
] | [deleted] | [
"They are basically an incomplete tutorial for your body to store on how to deal with a certain issue , it is complete enough for your cells to get the basic idea and instructions on how to deal with the issue but it is incomplete enough to never allow your cells to learn how to fully utilize the powers of the inst... | [
"You can think of antibodies as an ",
". When the arrest warrant is released, it calls in the law enforcement to take out the bad guy. The antibodies \"tag\" the pathogen in the body, which then calls in other immune cells (law enforcement) to kill it.",
"When we receive vaccines, what are trying to do is make ... | [
"Maybe this ",
"graph",
" will help. The first exposure causes plasma cells and antibodies to be made; the second exposure causes even a stronger response with longer-lived plasma cells and antibodies with higher affinity. ",
"As to why some vaccines require boosters and some don't I'm not really sure. I'm un... |
[
"If you touch a live wire at a rate equals to the line frequency (i.e. 50 Hz) such that the touching is synchronizeed with zero crossings, will you be conducting electricity?"
] | [
false
] | null | [
"If you have an load and you connect it to AC for very brief periods of time during which the voltage across the leads is zero, no current will flow. Your body would not be able to achieve that type of precision of movement, but an electrical component like an IGBT or MOSFET could."
] | [
"Electronics can quite easily and do match this frequency.\nThis is done to reduce switch-on currents - basically the load \nis turned on at the zero crossing, this results in a steady rise of the current instead of a steep step, which causes noise in the power grid."
] | [
"To answer your question in different terms, voltage is also referred to as potential. Just as an object on the ground has no potential energy, an electrical wire with no voltage has no potential. So at 0 volts there is no potential and therefore you would not conduct electricity. You would have to be really accura... |
[
"Is it possible to set up a series of mirrors to reflect light in a long enough path so that a person can visibly notice a difference from the point the light is turned on, until the end of the path?"
] | [
false
] | I always wondered if you had a source of direct light (a laser or something similar) and set up a series of probably thousands (or more) mirrors, could you tell the difference from when the light is turned on? As in, when the light is turned on, is there a distinguishable difference in time until the light reaches the ... | [
"...meaning it effectively \"goes slower\". The distinction is real but not relevant to the current discussion, Captain Pedant."
] | [
"Yes, but not very easily. You would need to run the light through a fiber optic cable wrapped 8 times around the planet to get a delay of a single second. "
] | [
"Yes. A good example is bouncing a laser off of reflectors left by the Apollo astronauts on the moon. It takes the light about 2 seconds to reach the Moon and 2 seconds to come back for a round trip of 4 seconds.",
"One of the earlier experiments to determine the speed of light involved sending a flash through ... |
[
"In a post-collapse scenario, would most nuclear reactors eventually melt down?"
] | [
false
] | I'm imagining a scenario where suddenly, all nuclear engineers have disappeared and there is no longer anyone who can man the reactors. I understand many Gen III and later reactors have passive safety systems, but I believe most operating reactors lack these systems. Does this mean a likely nuclear catastrophe at most ... | [
"In the normal likely collapse, the grid would go first. The reactors would 'trip' because there would be nothing to absorb the power. Excess heat would dump into a suppression chamber or condenser until the core cooled. The unit would then wait indefinitely until capable people could repair the grid and restart... | [
"The key thing is you need manual action to cool the reactor down to cold shutdown (mode 4 for BWRs and 5 for pwrs). ECCS and safety systems do not accomplish vessel cool down automatically. And as you've said, once you lose active cooling it's only a matter of time before the vessel boils again. Even years later. ... | [
"Rcic/HPCI in bwr designs and turbine driven aux feedwater in most PWR designs utilize steam to drive injection systems. These systems use steam from the reactor/steam generator (bwr/PWR respectively) along with dc battery power for valve control. For pwr plants, I believe the turbine driven aux feed pump (tdafp) e... |
[
"Do electrons still bounce around inside superconductors?"
] | [
false
] | I know that in a regular conductor the electrons you push in at one at one end are not the same electrons you get out the other end. They can bounce between atoms within the conductor for thousands (millions?) of years before finally making it out the other end. Does that behaviour still apply in superconductors, or ar... | [
"Yes, they still bounce around, but they do it as ",
"Cooper Pairs,",
" trading a metal-lattice Phonon (quantum of thermal vibration) as they go.",
"In resistive metals a moving electron does work upon the crystal lattice and slows down, while the lattice then radiates away vibrations as heat. In other words... | [
"So do these Cooper Pairs bounce into and interact with other Cooper Pairs, like single electrons in a non-superconductive material, or do they simply \"inchworm\" through the entire material pair by pair?"
] | [
"Ok. So the first thing you should realize is that electrons are indistinguishable. We have no way of knowing if the electrons you push in at one end are the same electrons that you get out the other end, and it isn't even a meaningful question since electrons are indistinguishable.",
"But this picture of elect... |
[
"Did early humans organize into family units like modern humans do?"
] | [
false
] | Did early humans have families like what we know now? with parents and children living as a group? | [
"The only real answer is that we can't really know. ",
"Kinship",
" structures range wildly all over the world. The only thing one could say with any amount of confidence is that that children were taken care of to some degree, but by who we have no idea."
] | [
"Yep. The short answer is: \"we don't know\".",
"Based on archaeological evidence, the size of a typical \"band\" of people, a group of humans who foraged a territory together, varied significantly. Some bands were as small as 4-6 people. Others were as big as 100 people or more. It probably depended upon what th... | [
"From various lines of evidence, we know that species as early as Homo heidelbergensis hunted in packs. This suggests a strong social structure, possibly comprised of at least one \"family\", although not necessarily a traditional modern family. If so, and if you consider H. heidelbergensis to be an ancestor of H. ... |
[
"How long will it tale geologic processes to erode Mount Rushmore?"
] | [
false
] | I'm not sure what type of rock the mountain is made of but how long will it take for the faces to become unrecognizable as an unnatural modification to the landscape? | [
"I ask this because I feel in 50 to 100 thousand years our written history mat be lost, but the mountain will still exist. How will it but interpreted."
] | [
"The mountain is granite, which is pretty tough. according to the ",
"National Park Service",
", it is eroding at the rate of one inch per 10,000 years. So, they should still be recognizable for a long time yet."
] | [
"That number is waaaay too low. That erosion rate would assume that in the entirety of earth history (4,500,000,000 years) you could erode just 11.43 km of granite.",
"While that erosion rate may be true of this particular window in time, over a period of 10,000 years the climate and environment can vary conside... |
[
"How much would it take to throw the earth out of a safe orbit?"
] | [
false
] | [deleted] | [
"anything big enough to significantly alter our orbit would be big enough to kill every last one of us. ",
"And that line about if we were ten feet closer/farther is utter nonsense. "
] | [
"Correct, and correct.",
"Impact of a comet weighing 0.0000001 times the Earth's mass would kill all of us, while barely altering the planet's orbit."
] | [
"A rogue planet passing near Earth would alter our orbit without killing everyone."
] |
[
"Why can our eyes precisely lock onto objects, but can't smoothly scroll across a landscape?"
] | [
false
] | null | [
"Eye movement is controlled by a couple different mechanisms that are essentially reflex mediated. The first is saccadic movement. This is the fast, voluntary movement you use to 'lock onto' an object. Saccades can rotate the eye up to 500",
" per second. The movement of the eye is so fast that there is a phenome... | [
"The first is saccadic movement. This is the fast, voluntary movement you use to 'lock onto' an object.",
"Interestingly, saccadic movement is a fine motor skill that can be trained. Educators are increasingly looking into the impact of saccadic movement on reading, such as:",
"Background. Eye movements are ne... | [
"I would add to this that smooth pursuit is usually difficult to do without a target. Normally, we do not need to slowly scan over a static scene. We can get more information from a static scene by making saccadic movements and getting disparate parts of the scene to fall on the fovea. However, smooth pursuit can b... |
[
"When I look at a star, what exactly am I seeing?"
] | [
false
] | By my understanding, they are basically all like our sun, albeit in different stages, but am I seeing them in the past? | [
"The most common type of stars are red dwarves (M type stars). However they are smaller than our Sun (~0.1 to ~0.5 solar mass) and much dimmer. Therefore many of them are not easy to spot with a naked eye unless they are fairly close. More massive K stars and even more massive G stars (like out Sun) are less common... | [
"Therefore many of them are not easy to spot with a naked eye unless they are fairly close.",
"Actually, none of them is visible to the naked eye under normal conditions. There is one star called ",
"Lacaille 8760",
" which might be visible to some observers under the most perfect conditions (age less than 30... | [
"There's different types of stars, but yes. Our sun is a star.",
"As for the time delay; the stars you see in the sky are so far away that it takes tremendous amounts of time for their light to reach earth. ",
"If i remember correctly, light travels 186k miles per second. So a star being as close as 10 lightyea... |
[
"A question about radiation in space"
] | [
false
] | After reading several articles about the amount of radiation astronauts would absorb on a two-year trip to Mars I wonder, what would happen if either the ship or the astronauts themselves were surrounded by a pocket of water on their journey? | [
"The halving mass of lead is 12 g/cm",
" and the halving mass of of water is 18 g/cm",
" so it makes more sense to use lead shielding. However, since you need to take along a supply of water, it might as well be used in addition to the lead assuming the cost of an envelope type container doesn't out weight the ... | [
"This was actually being considered as it would definitely be effective. While it may not be feasible to cover the entire ship with water (too heavy) it is currently being researched if it can be used to protect astronauts when they spacewalk.",
"Meaning, they wanna put water in the spacesuits."
] | [
"Any amount of extra material is generally helpful, unless that material tends to stop incident radiation by giving off more dangerous forms of radiation. Then the issue becomes cost. So, somehow getting a layer of water between various layers of the craft's superstructure would help (maybe melt off a chunk of come... |
[
"Why would the immune system attack the eyes, if it knew they were there?"
] | [
false
] | null | [
"There are organs in our body that are immunologically isolated from the bloodstream:",
"Why wouldn't lymphocytes react to everything in our body? Well, during childhood, T lymphocytes are trained in the thymus and are exposed to basically*** all the self antigens that the blood touches. If no antigens specific t... | [
"Could we theoretically train our own immune system on these things as children? Kind of like a reverse vaccine?"
] | [
"I guess it could theoretically be possible, but might require extensive treatment (multiple doses at different intervals) while also having the risk of making the patient (which would be an infant!) non reactive to some real non self antigens (prone to infections).",
"I sincerely don't know, but would love to re... |
[
"Why does the integral of 1/x result in a logarithm? Also, why does logarithm have base e?"
] | [
false
] | I think it seems too beautiful and amazing that this is just a coincidence that the integral of 1/x results in a logarithm (much less for that logarithm to have a base of one of the most useful numbers in mathematics, e) for it to just be coincidence. Can someone come up with a proof, or at least a logical argument, fo... | [
"The function 'log(x)' (here I mean natural logarithm) is usually defined as the integral of 1/t from 1 to x. You can prove that the integral has the properties you'd expect out of a logarithm, if that makes you feel better. Try it yourself, first show that log(1/x)=-log(x) by using the definition (set the upper bo... | [
"The function 'log(x)' (here I mean natural logarithm) is usually defined as the integral of 1/t from 1 to x",
"This is the first time I hear it defined that way... I usually hear it defined as the inverse of the exponential function e",
" and then it's trivial to show that d/dx log(x) = 1/x using the \"inverse... | [
"Explicitly, log(x)=integral of dt/t for t=1 to t=x. By the Fundamental Theorem of Calculus, this is true because the derivative of log(x) is 1/x (and log(1)=0). You can prove this through the equation e",
"=x. Setting y=log(x) and implicitly differentiating e",
"=x with respect to x, we get, through the chain ... |
[
"Recently, it has been speculated that gravity causes wave function collapse and that entanglement causes gravity - are these two ideas compatible?"
] | [
false
] | I may be misunderstanding the point of these two articles but those were the ideas I took from them: "But the incompatibility of general relativity and quantum mechanics itself suggests that gravity might behave differently. One compelling idea is that gravity could act as a sort of inescapable background noise that co... | [
"The second paper is about a parallel between pairs of entangled quarks and wormholes, not quarks being held together in hadrons."
] | [
"I didn't carefully read the articles you linked to but the idea that gravity causes wavefunction collapse is not that new actually, and has been championed by Roger Penrose, and bears his name: ",
"Penrose Interpretation",
"Regarding wormholes connecting quarks... that sounds really bizarre, and I'm surprised ... | [
"There is empirical evidence for the existence of gluons, they have been experimentally observed.",
"Well, ",
" have not been experimentally observed. Only effects that so far can only be explained by the existance of gluons (such as jets of hadrons during hadron collisions) have been observed. That ",
" co... |
[
"Is there ANY scientific evidence to suggest that you can influence the probability of your offspring being a particular gender?"
] | [
false
] | [deleted] | [
"If your old wives' tale involves ultracentrifugation of a semen sample to separate sperm by the mass difference between the X and Y chromosomes, then there might be something to it.",
"EDIT: That's the way it's often done for the livestock industry and perhaps some humans - that or sorting the cells with a fluor... | [
"I believe they're using a flow cytometer (reviewed ",
"here",
", ",
"here",
") these days. Reportedly it's 90% effective and has been successfully applied to cattle, sheep, pigs, horses, elk, domestic cat, domestic dog, some wild cats, sika deer, swamp buffalo, and probably others by now. ",
"This paper"... | [
"The 'X'. It's not just an arbitrary choice of letter; they look like their shapes. The 'Y' is missing most of one arm."
] |
[
"Could Dzhanibekov effect be at play in causing the periodic reversal of Earth's magnetic field?"
] | [
false
] | I'm not sure if this is a silly question or not: This video has been posted to Reddit a few times now demonstrating the Dzhanibekov effect, which causes rotating objects in space to "flip" weirdly on one of the axes of rotation... My question is, could this effect be responsible for the periodic reversal of Earth's ma... | [
"No. The ",
"'Dzhanibekov effect'",
" requires three distinct principal moments of inertia, whereas the inner earth should be symmetric about the Earth's rotational axis. In simpler terms, that effect only works for strangely-shaped objects."
] | [
"The earth's magnetic field is generated by small electrical currents in the liquid outer core which are generating small magnetic fields. These magnetic fields are aligned due to the Coriolis effect from the earth's rotation. Having a solid metal core in the middle of the liquid outer core causes little variatio... | [
"How much do we actually know vs. assume about the moments of inertia for the [mass?] that's generating our magnetic field? Is it conceivable that it ",
" have multiple moments of inertia?"
] |
[
"If somone gets the COVID-19 vaccine, would the PCR test come back positive in the weeks to follow?"
] | [
false
] | null | [
"The RT-PCR test looks for the presence of certain RNA sequences, and will only give a result if those exact sequences are present. From a quick look at the COVID virus genome, neither of the regions used in the official CDC test are in the spike protein, which is the part of the virus used in the front-runner vacc... | [
"No, the mRNA used for the vaccine is not the same region of the viral genome that the PCR test detects.",
"The vaccine codes for the spike protein, and the PCR tests usually use primers that bind to the region of the genome encoding the nucleocapsid."
] | [
"And he said detectable \"in the weeks to follow\", to my understanding the mRNA from the vaccine is degraded in the body within hours (or days?), but the antibodies persist. So there would be no detectable mRNA even a few days after getting a vaccine."
] |
[
"Does the moon have a different apparent vertical orientation in the two hemispheres?"
] | [
false
] | Put plainly, would the moon appear upside down to me if I went to Argentina or Australia (I live in the U.S.)? Edit: Thanks so much everyone! This was probably the most mind-blowing fact I've learned in a long, long time. | [
"Take it to the extreme and its easier to visualize.",
"If you stand on the North pole and the moon is on the horizon, imagine a big A on the surface of the moon, right side up.",
"TIME IS FROZEN FOR THIS ILLUSTRATION (the moon does not move, only you)",
"Now travel south toward the mooon. The farther south ... | [
"Yes. Yes I suppose it would appear \"upside down\" in the southern hemisphere (assuming you are from the northern hemisphere). Wow. I never thought about that. "
] | [
"Yep, it looks like ",
"this",
". I've submitted a few moon pics to reddit in the past and always get the \"upside-down\" comments. I live in New Zealand but that pic was taken in Australia."
] |
[
"Whenever matter/antimatter annihilation is mentioned it's almost always hydrogen/anti-hydrogen. What would happen if it were not the same (anti)elements interacting?"
] | [
false
] | Say, if you had an atom of anti-hydrogen come into contact with a gold atom, would you get a platinum atom and a lot of energy, or would something else occur? Further along those lines, what if the anti-hydrogen reacted with a radioactive element, such as uranium? | [
"But atoms aren't individual particles. I think he's asking if nuclei can partially annihilate. "
] | [
"Particles only annihilate with their own antiparticles.",
"So an electron and a positron can annihilate, but an electron and an antiproton can't."
] | [
"Yes, they can."
] |
[
"Why does it happen and what is happening when you get a ringing randomly in your ear?"
] | [
false
] | null | [
"Sounds like you're referring to ",
"tinnitus",
". ",
", according to Marion and Cevette. It may be defined as any sensation of sound for which there is no source outside the individual. ",
" (nonvibratory and vibratory, in the terminology of Fowler). The tonal type is by far the more common and is what is... | [
"Well, I don't think he was referring to a constant tinnitus. I experience what I believe OP does often enough, that my ear suddenly starts to ring -- tonally -- at arbitrary times. Not always, just now and then, and with unchanged ambient noise."
] | [
"So are you saying, let's give a scenario I'm out target shooting with a .44 magnum when I shoot that gun and the after effect is my ears ringing this is because my body had a sudden change in pressure waves that affected the blood flow and everything else you explained? Or is it just be cause of the loud noise and... |
[
"What makes MIG/TIG weld fumes so dangerous?"
] | [
false
] | Weld fumes are really dangerous, causing bronchitis or lung cancer over a long period of time if inhaled, but what I don't understand is how steel and argon can have a reaction that creates something so toxic when both aren't used up in a reaction and both aren't toxic to begin with. What's in weld fumes that make them... | [
"When you say \"steel and argon aren't toxic\", you are mistaken. Toxicity depends on not just what you get into your body, but on how you get it in, and how much you get. ",
"An excellent example of this is mercury. You can swallow small to moderate quantities of liquid mercury with no harm. But even a small amo... | [
"Mercury, consisting of unionized mercury atoms, first crosses into your blood (from your lungs) and then into your brain. In the brain, it is ionized; normally, this would make it easier to excrete it (because ionized mercury can bind to other compounds and that makes it easier for your body to get rid of it); unf... | [
"Asbestos would*?"
] |
[
"How do radio antennas work?"
] | [
false
] | I have been wondering this for a few months now, I know that RSSI (Receiver Signal Strength Index) is a range of voltage. Does this mean that when an antenna is subjected to a radio wave it always applies a voltage to the receiver? Another part of this question is how do transmitter antennas work, I know that P=V*I but... | [
"RSSI is a measurement in dBm typically. (where 0dB is 1mW of power) a receiver will always be subject to an input voltage/current from the antenna, but unless there is a specific signal it will be at background noise levels, usually around -80+ dBm.",
"current flows due to the characteristic impedance of the cab... | [
"First: In high-frequency you cannot think about voltage and current like in the DC case. P = V*I is not necessarily correct. The thing is that electric signals move with light speed which requires extended calculations at higher frequencies, in the air but also in any conductor. Simply because the signal is too sl... | [
"The signal source sends out a signal, like a voltage pike or similar.",
"By this you mean voltage spike?",
"Another question: how does this transmit information, I can understand if the receiver voltage is equal or proportionate to the Tx. voltage."
] |
[
"In lab testing with animals, how do you know when they are experiencing an invisible symptom?"
] | [
false
] | I was researching tinnitus as I have Meniere’s and saw that there was testing on lab rats with medication to see if they have more or less tinnitus. How do they know a rat is experiencing that at all? How can you tell if it’s better or worse for them? Adding link per request: | [
"If this is peer reviewed paper then they should definitely report the methods for determining improvements in outcomes. ",
"Most likely though they expose both treament groups to a stimulus and see which one responds to it. ",
"Maybe they found out the frequency at which tinnitus occurs and then play similar s... | [
"Link to research attached to main post."
] | [
"From the paper:",
"Acoustic trauma caused a significant increase in the auditory brainstem response (ABR) thresholds in the exposed animals",
"...",
"Hearing levels were measured using auditory brainstem response (ABR) thresholds in both the ears of exposed and sham animals before the acoustic trauma, in bot... |
[
"Why does mint make your mouth cold?"
] | [
false
] | I'm talking about when you chew minty gum or eat a mint, and drink water or breathe. I'm not sure how to explain it other than your mouth going cold. | [
"Menthol is used as a mint flavoring. It activates nerve receptors that detect cold."
] | [
"Yes, your mouth actually \"thinks\" it's about 4 degrees (Celsius) than it really is. It doesn't just feel \"like\" cold - it actually feels cold! Pretty nifty! ",
"Compare this with capsaicin, which activate pain receptors. It doesn't just sting \"like\" pain - it's actual pain!",
"The intensity for both is l... | [
"It's a trick of the receptors, from the menthol in the mint. Even though the air you breath in isn't cold, its colder than your mouth already is so your nerves are tricked into thinking its a lot colder than it really is. ",
"Check this out: ",
"http://www.thenakedscientists.com/HTML/articles/article/dalyac... |
[
"When you delete something where does it go?"
] | [
false
] | null | [
"Why ",
" it simply vanish?",
"(In practice, most computer systems don't actually do anything with the data when you delete it; they just tell other programs they're allowed to write over it. But writing over it ",
" just make the data vanish.)"
] | [
"The data is never deleted from the disk, their entries are deleted from the \"",
"file index",
"\" so that they can be overwritten."
] | [
"Data on hard drives is represented by 1's and 0's. All grouped data (files), are accompanied by a delete flag. For data in use, this is set to 0, so that it won't be overwritten. When you delete something, in almost all cases, the only thing that happens is changing this flag to 1, which is simply indicating that ... |
[
"Are there people who exist on the opposite end of the spectrum from sociopathy- i.e. an \"anti-sociopath\" or a hyper-empathic individual?"
] | [
false
] | There's so much written about sociopathic and psychopathic people, but is there any information on the existence of people who are their opposite? In other words, someone possessing such an overdeveloped conscience, empathy, and a sense of the rights of others that it could possibly be considered debilitating or even ... | [
"The closest condition that I can think of like this is called Williams syndrome (",
"http://en.wikipedia.org/wiki/Williams_syndrome",
"). People who have it tend to be overly trusting, cheerful and friendly. They also have a distinctive appearance and some negative physiological symptoms. However, I believe th... | [
"This is going to sound mean, but most people only ever see the people with Down's syndrome that are allowed to go outside; they keep the rest locked up because they are a potential threat to either themselves or their environment. It's probably this type of selective exposure that accounts for the cheerful stereot... | [
"Maybe not exactly what you're looking for since this isn't exactly a disorder - but have you read about ",
"highly sensitive persons",
"? "
] |
[
"I've heard it said that there are some foods that require more energy to digest than they provide as energy to the body. True?"
] | [
false
] | I have heard it said that there are some foods that require more energy to eat and digest than they provide in terms of food energy to the human body. Celery is one example I distinctly remember as being part of this. Is this true or even nearly so? If I crashed on the Desert Island of Celery, would I be doomed? | [
"Upvoting because the link is good and should be seen, but your conclusion about it is wrong... try reading things you link.",
"Basically, negative calorie foods are a myth."
] | [
"From the article:",
"Celery, a commonly cited negative calorie food, actually requires only about 10% of its food energy content to be digested (due to the thermic effect)."
] | [
"This is a common claim made by various dieting websites, although it is assumed to be incorrect - there's no scientific evidence to suggest it to be true but at the same time it hasn't been specifically studied.",
"One of the reasons for the claim is sometimes confusion between calories burnt by thermic effect a... |
[
"Would be able to see a inside of a 3d egg if we were looking at it from the 4th dimension?"
] | [
false
] | [deleted] | [
"If it is a purely 3 dimensional object in 4 dimensional space, then yes.",
"Of course there are no 4 dimensional eyes in this universe, but for the sake of argument, let's consider that you are able to \"see\" point P from your perspective if there is a straight line from you to P that passes into no solid objec... | [
"What they said. You might read \"Flatland\" by Abbot (it's public domain).",
"But yeah, to a 4D actor your insides are just as reachable as your outsides. Just like you can lift a pencil off the \"Start\" of a line maze and just make an X on the finish, ignoring any intervening lines. Another interesting ability... | [
"Obviously this is getting very hypothetical, but the body mainly depends on the chirality of molecules inside it relative to other molecules inside it. So you probably wouldn't die until you tried to eat something. As long as you could find mirror food though, you should be ok.",
"The only reason I qualify all o... |
[
"Why is bisexuality so rare?"
] | [
false
] | I understand the evolutionary principles that have been used to explain how "gay genes" can be permitted to exist in a species that reproduces via sexual reproduction - concepts such as the kin selection theory and other such societal/community factors. I can accept that heterosexuality may be the most numerous categor... | [
"From anecdote from people I know I think 2 is more likely, but even more likely than that is that sexuality is probably a ",
"bimodal distribution",
". Two peaks at the edges, but blending to some continuum between. Bisexual leaning heterosexual etc. There's also some suggestions that the distributions are dif... | [
"Sexuality is a psychosocial characteristic at least as much as it is a biological one. Our designations of strait, gay, and bi are not universal. I wouldn't spend to much time looking for the genetic basis of sexuality then I would looking for the genetic basis of sports preferences. I'm sure there out there, b... | [
"Layman speculating.",
"I wouldn't spend to much time looking for the genetic basis of sexuality then I would looking for the genetic basis of sports preferences.",
"Except that sexual orientation has obvious evolutionary ramifications. From a simplistic perspective you would expect that any genetic causes for ... |
[
"Why is it that the neutron to proton ratio decreased as the universe cooled down in the early universe?"
] | [
false
] | null | [
"Two reasons.",
"The neutron is slightly more massive than the proton, which means that in equilibrium, one expects more protons than neutrons by a factor of e",
"Once neutrons and protons fall out of equilibrium (which is basically when all the electrons and positrons annihilate, leaving behind about 1 electro... | [
"I do not know if this explains everything, but neutrons decay into protons."
] | [
"excuse the syntax, but I think the question is still clear"
] |
[
"How do things like Bop It manage to generate pseudorandom numbers?"
] | [
false
] | In a normal computer, random numbers are generated by using various data and manipulating them until you get a single number, right? So how come a Bop it, or any other single-serving machine like that, which contains no data at the time of it being turned on, manage to create a random number that is different every tim... | [
"A very common way to generate random numbers in a small embedded device like that is to have a fairly fast free-running counter. When the device receives some input (like the player pressing the start button) the counter is read and that can provide a dozen or so bits of entropy, which is plenty to make a game lik... | [
"Like ",
"/u/manlymann",
" said twice, it's using a pseudorandom number generator to generate the values. Most likely, it's generating numbers between 0 and either 2",
" - 1 or 2",
" - 1 , and using the remainder of that number divided by k (where k is the number of distinct bop it actions) to figure out th... | [
"rand()",
" isn't magic, you have to seed it with something random enough so you don't start off with a small number of possible prng states. The real question is where is the device pulling entropy from so you don't have the same sequence every time."
] |
[
"If you are knocked out and fall into water, would you unconsciously hold your breath or take in a big gulp of water?"
] | [
false
] | null | [
"The slightly circular answer is \"it depends if you're breathing spontaneously or not.\" If unconscious and breathing on your own outside of water, you'll breathe in water. (Even conscious drowning people may not be able to hold their breath to the point of unconsciousness; involuntary breathing may take over, fil... | [
"Humans have a dive reflex that is activated by cold water on the face (trigeminal nerve). Regardless of whether one is conscious or unconscious, the dive reflex would be activated. This would stop a person from breathing in/out, slow heart rate, slow peripheral blood flow to ensure that oxygen was able to get to t... | [
"Ahh thank you. Never heard of this reflex before "
] |
[
"Is there any substance to the no-shampoo movement?"
] | [
false
] | I'm always frustrated when looking up anything about cosmetics or health/fitness; there are so many fads and so much woo that often turn out to be baseless. That said, the idea of no-poo or poo-minimal life is intriguing to me. I wash/condition daily and my straight hair is usually getting uncomfortably greasy by the e... | [
"As far as I know, I'm the only panelist with shampoo \"specialty\" and I have to admit that my background provides absolutely no guidance. I've messaged some biology panelists to see if they know something about the sebacious glands which oil up hair. If there is a feedback loop, the theory may have some credence ... | [
"Based on what I can determine, you're washing your hair with vinegar and then conditioning it with the baking soda.",
"It's the other way around.",
"This is, seriously, exactly what shampoo and conditioner do (and no, its not because of some acid/base thing...).",
"The principle is the same although baking s... | [
"Well I'll take a crack at this, dermatology isn't my specialty, but I spend a lot of time with dogs and cats, so I know my fair share.",
"Their claim about the oil production is true. Sebaceous glands will produce less oil when the body's natural balance system realizes what is going on. So if you were really wi... |
[
"If a human pants (like a dog) will they actually cool themselves down?"
] | [
false
] | null | [
"If you move air over a body part with a rich blood supply, like the tongue, you will lose heat through convection. However, a dog is obviously going to be better adapted for this, and more efficient."
] | [
"It would work, but there are more effective ways. ",
"But you would get acidosis pretty fast from unnecessary hyperventilation and your head would hurt. Try it. "
] | [
"This is correct more specifically as long as the air temperature is lower than that of the body energy in the form of heat will be transferred to the air (by convection and conduction) which you then breathe out."
] |
[
"Can someone explain how lipoedema can grow without the required energy intake?"
] | [
false
] | I have recently discovered and at first dismissed it as "yet another excuse for fatties to fat", but the NHS page says it doesn't improve with dieting? if we simplify TDEE to: (base energy to survive) + (base energy to power daily activity) then in a patient with lipoedema it would be: ( + ) + (the energy to sustain th... | [
"I'm not a lipoedema expert, but your question seems somewhat obvious when we look at other cellular growth or metabolic abnormalities. You can't diet cancers away either."
] | [
"I think my question was poorly phrased, I mean, theoretically ",
" has to give, so does it affect organ function or just general energy levels? I mean, a cancerous tumor of that size would RUIN a person, but people with lipoedema seem to (from what I read) get by absolutely fine."
] | [
"The problem with cancer is that they can impede with normal organ functions. ",
"There are massive benign tumours as well. Furthermore, I think the enlarged fat cells aren't particularly dense and the way they distribute appear to be further away from important places (the organs).",
"If I understand your ques... |
[
"Do obesity rates drop during economic recession?"
] | [
false
] | null | [
"It's the opposite, according to science daily. Obesity rising makes more sense because food that's bad for you is cheaper than food that's good for you. That, plus the rise in depression and comfort eating makes for a perfect storm for obesity.",
"https://www.sciencedaily.com/releases/2018/03/180301094841.htm#:~... | [
"Science Daily just reposted a press release of peer-reviewed work. Here's the press release and research they are talking about: ",
"https://www.city.ac.uk/news-and-events/news/2018/03/2008-great-recession-led-to-increase-in-obesity-diabetes-and-mental-health-issues-says-study",
"https://www.sciencedirect.com/... | [
"It's also cheaper to stay home and sit on the couch than it is to drive to destinations and engage in fun outdoor activities."
] |
[
"Is it possible to burn a high calorie food to get water hot enough to smelt metal?"
] | [
false
] | As I've always been told, a calorie is the unit of energy required to heat up a kilogram of water 1 degree Celsius. I know that may not be a lot, but if Epic Meal Time burned their 100,000 calorie burger and was somehow able to contain all of the heat, could they get water hot enough to smelt metal? | [
"You gotta think of the heat equation:\ndQ= m Cp dT",
"Where dQ is a change in heat, m is a mass of the thing you're heating, Cp is the thing's specific heat (mostly constant and specific to the material), and dT is the change in temperature.",
"You might realize from this equation that if you have a massless e... | [
"Someone created a torch for cutting metal using oxygen and bacon.",
"Here's the ",
"link"
] | [
"So technically its possible but it would require something other than water? So a furnace of some sort could be heated?"
] |
[
"AskScience AMA Series: We are researchers studying biological rhythms and we want to 'lock the clock' to permanently end daylight saving time - ask us anything!"
] | [
false
] | We are from the Society for Research on Biological Rhythms ( ), an organization of international scientists, clinicians, and industry experts who promote basic and applied research in all aspects of biological rhythms. We are dedicated to advancing rigorous, peer-reviewed science and evidence-based policies related to ... | [
"I'll bite. While I'm not a fan of having to change the clock twice a year, how much of an impact does it really have on one's health? A great number of people travel to different time zones multiple times per year (or week even). Given that a traveler's Circadian rhythm can adjust to large changes in time zone ... | [
"What test cases have you studied? I'm from Western Australia where it's been trialled a couple of times and rejected at referendum each time, but we're treated like Luddites by East-coasters.",
"This makes me wonder: are there geographic arguments for and against? In Perth WA, the summer afternoons can be brutal... | [
"What's the best advice you can give someone to maintain a healthy circadian rhythm? What exactly is a good rhythm?",
"Should one:\nUse blue light blockers at a certain time?\nWake up at the same time? \nEat breakfast at the same time?"
] |
[
"If I cross my eyes, do I risk the chance of getting a lazy eye?"
] | [
false
] | EDIT: Yes, I suppose I am referring to strabismus, not amblyopia | [
"if you're talking about strabismus i believe there is a possibility. while vergence is a natural visual reflex, strabismus can be the result of physical as well as neurological dysfunction. while it is highly unlikely that constantly engaging in vergence (crossing eyes) will result in cranial nerve damage, damage ... | [
"Edit; no.",
"Theoretically, its possible.\nHere's why.\nLazy eye is caused by an imbalance in the strength of opposite muscles that hold your eye in place. (There's actually more to this I believe, but lets just assume that there is one muscle that pulls left, one that pulls right, one for top, one for pulling t... | [
"Just to clarify: \"Lazy eye\" refers specifically to amblyopia, which is a developmental disorder of vision and, while related to strabismus (which some of you seem to mean), is NOT the same thing. Children who have strabismus as they grow up can develop amblyopia because the double vision resulting from strabismu... |
[
"Should doctors be allowed to prescribe placebos?"
] | [
false
] | null | [
"Whether something should or shouldn't be done is not a science question. Please post to a different sub"
] | [
"What subs do you recommend?"
] | [
"Perhaps an ethics or philosophy or medical sub"
] |
[
"A dirty filter is better than a clean filter?"
] | [
false
] | I replaced the air intake filter in my car this past weekend and it reminded me of something my boss said last spring. We were having pollen issues in our lab, and he made a comment how a dirty filter should function better than a clean filter. It sort of made sense, but is this true? It makes me think of like a pac... | [
"As the filter clogs, the HVAC system must work harder to push less and less air through the filter. As this progresses, eventually the system will not be able to provide the minimum CFM it was designed to. This means if your lab was designed as a negative or positive pressure system, it may no longer be. Also, dus... | [
"I don't know. I suspect that it isn't cleaner, because now theres increased pressure on the filter, and you're forcing the impurities through it. But I don't have any actual evidence of this."
] | [
"The problem is that as it gets dirty, the filter gets obstructed, and its harder to get air through it."
] |
[
"When a clock is so accurate that it \"only loses one second in X billion years,\" or something, how can we possibly know that? What do we compare it to?"
] | [
false
] | It used to be that to gauge the accuracy of a clock, you'd compare it to the position of the sun in the sky. But we've since learned that the Earth's rotation is always slowing, so that's not terribly accurate. And now that we have atomic clocks and a second isn't even as 1/86400th of a day anymore, how do we know how ... | [
"We know the definition of the second as \"the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.\"",
"If we state that a clock only loses, say, one second in a billion years, it means it measures each of... | [
"That would leave a problem considering the meter is defined as the distance light travels in X amount of time."
] | [
"First:",
"Atomic clocks work by getting a cesium-133 gas, cooling it to near absolute zero (0K), and placing the gas in an adjustable microwave cavity. The microwave cavity is tuned to emit electromagnetic radiation (light) at the precise frequency corresponding the ground-state transition of Cs-133. (You tune ... |
[
"Why aren't we trying to colonize Venus? Why is Mars such the hot-shot?"
] | [
false
] | null | [
"I assumed that when you said colonization and contrasted with Mars, you meant on the surface"
] | [
"Such open-ended questions are better suited for our new-ish sister sub ",
"/r/asksciencediscussion",
". Please consider reposting there instead.",
"However, the answer to your question is likely the fact that the surface temperature of Venus is ~850° F."
] | [
"Why the surface? What's the temperature of the Venusian atmosphere at one bar? "
] |
[
"esophageal cancer"
] | [
false
] | Whats going in in the countries highlighted red here thats causing esophageal cancer to be so prevalent?, or are these places that don't have treatments? | [
"It is really hard to say. There are a lot of regional differences between cancer prevalence that we don't full understand, such as the high incidence of prostate cancer in the US. ",
"Wikipedia lists several risk factors for esophageal cancer. ",
"http://en.wikipedia.org/wiki/Esophageal_cancer#Increased_ris... | [
"The \"classic\" med school answer for the elevation in esophageal cancer in those Middle Eastern countries is the increased intake of hot beverages such as teas. Whether or not this is the case or if there are other factors that may increase the incidence I'm unsure.",
"Link to Pubmed abstract on this topic."
] | [
"Here's similar maps for smoking in males\n",
"http://upload.wikimedia.org/wikipedia/commons/1/1b/Male_Smoking_by_Country.png",
"and females\n",
"http://upload.wikimedia.org/wikipedia/commons/2/2a/Female_Smoking_by_Country.png",
"It doesn't exactly correlate."
] |
[
"Why doesn't dust fly off of a fan?"
] | [
false
] | Whether it is a cieling fan or a dust seems to always accumulate on EACH side (front/back) and edge. How come it doesn't fly off of the blades when they are spinning? | [
"Some does; however dust can have a charge, such as a static charge in which it sticks to another charged surface. Since ceiling fans are spinning they accumlate a static charge through friction with the air, and attract dust.",
"The static charge attraction is stronger than the centripetal force.",
"As another... | [
"This is correct but I would restate it this way: The fan drags the (very near) air around with it; the region where this occurs is the ",
"Boundary Layer"
] | [
"This is correct but I would restate it this way: The fan drags the (very near) air around with it; the region where this occurs is the ",
"Boundary Layer"
] |
[
"Can ethylene glycol stop an alcohol overdose?"
] | [
false
] | [deleted] | [
"No. Ethylene glycol is much more ",
"toxic",
" than ethanol. Ethanol, in fact, is the treatment for glycol poisoning. "
] | [
"if i'm not mistaken i believe ethanol is also used to treat methanol poisoning."
] | [
"That too. Same enzyme competition. "
] |
[
"Since star's are formed by gathering gas, will Jupiter or Saturn ever become stars?"
] | [
false
] | I got thinking about this, and couldn't find anything after a search. As in the title, since they are gas planets then are they still gathering gas and could they eventually (in the very distant future) become stars themselves? | [
"Stars aren't formed by just gathering gas, stars are formed by a collapsing gas cloud. That's a significant difference, because the first one implies stars could grow just by collecting stuff, whereas the second says, that a given mass just contracts to a smaller volume. ",
"Stars after formation emit stellar w... | [
"Would the star, before it collapses in on it's self and ignites look like a gas giant planet (only on a much larger scale) ? ",
"In short, no.",
"Star formation starts out with an pretty ordinary gas cloud, mainly made from hydrogen and helium and a small percentage of heavier elements. In these gas clouds, yo... | [
"Very interesting and informative, thanks! Here's a question then : Would the star, before it collapses in on it's self and ignites look like a gas giant planet (only on a much larger scale) ? ",
"Very interesting about the solar winds, so the sun sort of preserves how the planets were formed and protects them fr... |
[
"What is the most up to date scientific opinion on water fluoridation? If you can cite sources that would be much appreciated."
] | [
false
] | Title. My father is trying to convince me that it is horrible because he saw it on Dr. Mercola's website but I believe that to be unreliable. Anything that shows Dr. Mercola is an unreliable source is also welcome, again sources appreciated. | [
"Here",
" is the CDC's site about water flouridation studies by the National Academy of Sciences.",
"Here",
" is another site that specifically addresses some of the conspiracy theories and internet propaganda surrounding Flouridation."
] | [
"For anyone not wanting to click the link, fluoridation is considered a good thing at the concentrations which its normally added to drinking supplies."
] | [
"The latest scientific studies into the matter concluded that there is no clear link between fluoridated water and reduction in cavities. Another recent study linked fluoridation to higher rates of ADHD. A Harvard study from last year also found significant evidence that fluoride \"may adversely affect cognitive de... |
[
"How long would days be if the earth was twice as big? does the mass of the earth affect the rotation on its axis? and would the extra mass make its orbit around the sun longer or shorter?"
] | [
false
] | I have only been able to find videos about what would happen on earth is the planet got bigger. Like gravity is twice as strong, bigger and hotter core, bone density would evolve to be bigger. But I haven't been able to find anything on what happens in the solar system if that were to happen. | [
"There is no correlation between planet size/mass and rotation rate, there are a multitude of factors that determine how fast a planet rotates, but the mass isn't one of them.",
" For instance, Venus (almost the same size and mass as Earth) has a rotation period of 243 days, where Jupiter's is only 9 hours 55 min... | [
"Similarly, the orbit wouldn't change at all. Our orbit has more to do with the sun's mass than ours.",
"What would change is how other things moved because of us. The moon would have to move more quickly to stay in orbit, giving us a shorter month, or it would have to be further away (making it smaller in the sk... | [
"Always found it crazy that we're perfectly timed to get a proper solar eclipse. It won't always be this way, but we get to experience it."
] |
[
"Is it possible to weld under liquid gasoline?"
] | [
false
] | I am familiar with welding the outside of containers with fuel in them by using inert gas, however in one of my class's at college this idea of welding under liquid gasoline became a heated debate. Scenario: Liquid gasoline in a steel bucket thick enough so that welding through the bottom is impossible, and enough gas... | [
"An experiment is in order... "
] | [
"Got it. I'm not sure that I have any evidence per se, but you're missing a leg of the fire triangle. You have to have an oxidizer in order to have fire. If you are submerged and using a welding technique that does not involve the introduction of oxygen to the welding site, the conditions to cause an explosion simp... | [
"Sure thing. ",
"Here you go",
" "
] |
[
"Where do the bacteria responsible for armpit and foot odor come from?"
] | [
false
] | Symbiotic bacteria like E. Coli comes us from eating food that contains them, but what about the bacteria on the skin of our armpits and feet? These bacteria eat our sweat and produce that smelly odor we all hate. This used to be helpful when humans lived in the wild amongst other predators and the smell can help put o... | [
"These bacteria have lived on us our entire lives. As a baby passes through the birth canal, the newborn’s skin is colonized by the local bacteria and fungi. For C-section babies, the same thing happens the first time someone touches them. There is an entire biome on a human’s skin, and various changes to the perso... | [
"I'd like to add that the reason one starts to small is because they're able to multiple in much greater numbers under those conditions."
] | [
"What would happen if a person didnt do anything to get dirty but never washed in their entire life. Would this bacteria become visible and what would the person look like if it did?"
] |
[
"Since O2 is slightly heavier than N2, why doesn't the oxygen in the air sink to the floor?"
] | [
false
] | [deleted] | [
"The gases in the ocean are dissolved in the water. The random molecular movement in the water wiggles them around too much for them to be able to separate.",
"To be technical, in deltaG = deltaH - T*deltaS, the temperature is great enough that the entropy term is weighted largely enough that the entropy change t... | [
"Lemme ask if this is an appropriate analogy?",
"You have a jar filled with mixed multicolored sand. Even though the red sand is ground of the densest mineral represented, it would take too much energy to move the rest of the sand out of the way relative to their respective densities, so they stay fairly evenly d... | [
"Not exactly. It's not that there isn't enough energy to separate them, it's that it would decrease the entropy of the system too much, and the 2nd law of thermodynamics says that it is hard to decrease entropy."
] |
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