title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"What is the nature of the frequency factor, A, in the Arrhenius Equation?"
] | [
false
] | Hello! I am in my second semester of general chemistry. We are learning about chemical kinetics, rate laws, and reaction mechanisms. I understand the general concept described by the Arrhenius Equation and how to perform calculations with it. I am puzzled by the frequency factor A. My textbook defines it as the fracti... | [
"I have a feeling this is yet another case of lower level sciences getting simplified to the point that it's not quite true.",
"Before I answer your question I want to say that this is true of literally all of science. In science we develop models that capture all the variables needed to effectively describe the ... | [
"Yep, the constant approximation saves a ton of trouble in modeling a system and allows us to actually solve some of these rather annoying equations. You would be surprised how adding a simple linear term (ax+b) can turn an equation into Frankenstein's monster. ",
"That said there are problems with making those a... | [
"I'd like to add a note that is relevant based on ",
"/u/nirvanna94",
" 's answer.",
"The pre-exponential factor 'A' is an entropic term; this means its temperature dependence will actually vary very widely from reaction to reaction. In reactions with no state changes (i.e. solution chemistry or gas phase che... |
[
"[Weekly Discussion Thread] Scientists, do patents help or hurt scientific progress?"
] | [
false
] | This is our seventh installation of the weekly discussion thread. Today's topic is a suggestion by an AS panelist. Topic: Do patents help or hurt scientific progress or does it just not matter? This is not about a specific field where we hear about patents often such as drug development but really about all fields. Ple... | [
"They can both help and hurt. It's about finding balance. Too much patent protection makes it hard for someone to take existing tech and expanding it and modifying it, but no protection at all makes it less desirable to sink a lot of money into R&D. I generally side with the less protection side, as I've yet to ... | [
"'I'm not even going to try because someone will just steal it anyway",
"In pharmaceuticals this is actually a pretty extreme problem. Actual manufacture of of most drugs costs next to nothing, while R&D to develop the drug and perform clinical trials requires enormous amounts of capital. Once a patent runs out... | [
"Agreed, with the current pace of progress, a 17 year patent just seems too long. I'm sure it made more sense originally though."
] |
[
"Does the cost of food skew our perception of taste one way or the other?"
] | [
false
] | I was wondering whether free food tastes better than something you have to pay for. Or is it that once you pay a lot for something (ex $100 steak), your brain automatically tells you "Hey, this is going to be amazing because it was so damn expensive". I could think of examples either way, but was wondering what the ans... | [
"Small study on wine",
": Price influences preference. The small group in the study tended to prefer the cheapest wine when they weren't told the price.",
"Larger study--says there is very little correlation",
"In sum, in a large sample of blind tastings, we find that the correlation between price and overal... | [
"So the extra built in cost is just so it looks nice? Then McDonalds needs to invest more in $50 Big Macs that make you feel like a sir"
] | [
"Not really, but this article implies that the (known) price also influences the perception for food and anything else.",
"http://www.psychologytoday.com/blog/evolved-primate/201002/does-price-tag-have-taste"
] |
[
"How does E=mc^2 show that nothing can accelerate to the speed of light?"
] | [
false
] | null | [
"The total energy of a free particle/object moving at speed v is E = ymc",
", where y = (1 - (v/c)",
")",
".",
"If you take the limit as v goes to c, this quantity approaches infinity."
] | [
"E = mc",
" says nothing about being able to accelerate to c. E = mc",
" only applies for objects at rest."
] | [
"Oh. In that case, why cant objects accelerate to c?"
] |
[
"How dependent is the micronutrient content of food on the quality of the soil in which it is grown?"
] | [
false
] | For example, for a vegetable to have a decent amount of calcium, doesn't the soil have to contain calcium? And if so, how is this not depleted since most fertilizers I've seen only provide N + P2O5 + K2O? | [
"I am by training an agronomist but not by trade. You know that phrase \"you are what you eat\"? That is a very near literal phrase. Actually a better phrase is \"you are what you eat eats.\" ",
"There was a situation in New Zealand for a long time where sheep were dying from some unknown disease. It turned ... | [
"I'm not sure to what extent say an ultra calcium rich soil would impact the amount in the crop, as compared to just adequate quantities",
"I would expect that it would cause problems with other nutrients like magnesium."
] | [
"I'm not sure to what extent say an ultra calcium rich soil would impact the amount in the crop, as compared to just adequate quantities",
"I would expect that it would cause problems with other nutrients like magnesium."
] |
[
"What happened to the alleged cold fusion that Italian Andrea Rossi was working on?"
] | [
false
] | null | [
"Rossi was, I believe, convicted of fraud. ",
"Take this claim with an entire mine of salt.",
"[edit] the conviction was later reversed. It's still almost certainly a scam."
] | [
"What happened is that Rossi is still doing whatever he thinks he's doing. He hasn't allowed anyone to look at his thing, or perform their own measurements. (and quite a lot of problems have been pointed out with how Rossi measured things)",
"It's a media story really, not a scientific one. The burden of proof is... | [
"He ran out of hot air to peddle."
] |
[
"Does breathing in smells reduce the likelihood other people can smell them?"
] | [
false
] | Specifically we were discussing farts. If I fart I've been breathing it in in the vain hope that it reduces the likelihood that someone else can smell it. Any smell scientists want to explain how it actually works? | [
"So, your hypothesis seems to be that by breathing in the smell you are removing it from the environment and thus preventing others from smelling it. I believe we'll need to find out how many molecules you need to breathe in in order to smell something (the fart threshold), how much you can inhale in one go (breath... | [
"Well, does your body absorb the odor molecules when you breathe them in? Or are the gases just expelled when you breathe out again? Interesting question"
] | [
"Technically, yes, but practically, no. I'm half asleep, so I doubt I'll be able to explain how it actually works right now."
] |
[
"What could be the consequences of extreme harvesting of tidal energy?"
] | [
false
] | One of my favorite ponderings is what the extreme outcomes of normal activities could be. For example, if we took solar power energy TO THE EXTREME, and covered most of the surface of the earth in solar panels, we could end up affecting - among other things -the temperature of the planet by reducing the amount of heat... | [
"http://physics.ucsd.edu/do-the-math/2011/12/can-tides-turn-the-tide/",
"http://bowie.gsfc.nasa.gov/ggfc/tides/intro.html",
"tl;dr: ",
"Currently, water hitting already extant natural barriers in the world causes a slowing of the rotation rate that lengthens the day by about 2.3 milliseconds per day per cent... | [
"Bit of an odd way of saying the length of one day increases by that amount every century."
] | [
"If left unchecked, the slowing we talked about above would eventually slow the earth to the point where their rotations were equivalent. The moon appear to slow in transit across the sky, and eventually hang in one spot above the sky (not for everybody, you understand. Since its period is identical to the earth'... |
[
"Does sleeping too much harm our bodies?"
] | [
false
] | [deleted] | [
"Yep. And replicated in three large studies too. Even 8 hours will increase your chances of death.",
"http://www.guardian.co.uk/science/2004/feb/05/thisweekssciencequestions4",
"http://www.cbc.ca/health/story/2007/09/24/sleep-study.html"
] | [
"That cbc study is very poorly explained. They imply that the participants ",
", and that the study then went on for several years...",
"I have an extremely hard time believing that such a study has been conducted (and the guardian article doesn't make such extreme claims)--not to mention that they say they fo... | [
"All I have is anecdotal evidence, but I usually feel really sore and tired all day whenever I oversleep by more than a couple hours."
] |
[
"Will CMB ever disappear or as time goes will we see more recent CMB then the big bang one?"
] | [
false
] | Hi, sorry if this doesn't make any sense, i was reading "how to create a universe" by brian cox and they were talking about how important the cmb is as it allows us to peek at the time right after the universe cooled down. The question is are we in a perfect spot to observe the EM waves coming from that time or those ... | [
"The CMB will get redshifted more and more (making it harder to detect), but not disappear. It fills the whole universe, it doesn't matter where you are and at which time, you will always see it."
] | [
"I thought eventually space will have spread out so much that no light could reach you? I.e. everything is further away in light years than the universe is old in years (hope that makes sense)",
"Edit after mfb told me I was making no sense so I went and read again: I misremembered, the CMB will be so redshifted ... | [
"Yup, I just remembered something I had read wrong (not at all a physicist, shame on me).",
"Queation - does this mean not detectable with any technology available or does it mean that it would be impossible for it to be detected in any way whatsoever?"
] |
[
"Are phobias genetic?"
] | [
false
] | While I understand that the majority of phobias are influenced through life experience, are there certain phobias just hard wired into our family tree that are passed down? | [
"So as a general rule, most behaviors are ",
" 50% heritable. More specifically, about 50% of the variance of your behavior is explained by genetics.",
"However, we have to remember that very little is \"hardwired\" into our genetics. Behavior is not the result of Genetics + Environment. Rather, it is the resul... | [
"Behavior is not the result of Genetics + Environment. Rather, it is the result of Genetics x Environment, or the interaction between our genes and our environment.",
"Eh, the equation in my quantitative genetics class was Vp = Ve + Vg + Vgxe!"
] | [
"You might be more predisposed towards it, but it wouldn't be directly passed down. Part of a phobia being shared would have to do with similarity in environments and experiences you might share with someone else with a phobia."
] |
[
"A question regarding Down Syndrome ..."
] | [
false
] | Ok so hear me out. My mother has been working with special needs children for 13 years, and I have noticed that some of them have insane amounts of strength at the age of eight, also the same children are incredibly intelligent. So my question is (Please do not judge, I am trying to have utmost respect.) Is it possible... | [
"I don't see how. I'm no expert in genetics, but my sister has down-syndrome.",
"What it is is a mutation with Chromosome 21, called trisomy 21 appropriately because instead of a normal pair of chromosomes, there are three. The result is a laundry list of genetic defects including stunted growth, lower life expec... | [
"Relax, buddy. We're all here for answers."
] | [
"Beautiful answer, zyedy. I want to emphasize the point that since people with Down syndrome are generally infertile or subfertile, they do not reproduce and generate more people with Down syndrome, which is what you would expect if you were studying a step in evolution (the traits would need to be passed on). Do... |
[
"What distinguishes the artificial/'computer' brain from the human brain?"
] | [
false
] | null | [
"You're confusing artificial intelligence, which is basically the building of algorithms or numeric recipes that make human-like decisions, with actual computers like your laptop. You can think of computers as being boxes of electrical wiring, and algorithms as a set of instructions which tell the wiring what to d... | [
"Yeh, I think that calling this \"downloading\" is actively misleading. There's no brain to brain contact, it's just that some young animals are primed for quickly learning particular traits from their parents.",
"You may as well say that we \"download language\". We don't, we just learn quickly when we're young.... | [
"I have a BSc education in computer science and neuroscience, so I feel qualified to address your information and to go into more detail as you like.",
"The brain differs from a computer in a number of ways. There are similarities in that they each have a fundamental \"calculation unit\" - a better term escapes m... |
[
"How does infrared light heat objects up?"
] | [
false
] | I've been learning about the photoelectric effect in my physics class, and one of the formulas that I learnt was that the energy of a photon of light is given by E=hf. From this equation, ultraviolet light has more energy than infrared. So why is infrared able to heat up objects and ultraviolet not? Temperature is a me... | [
"Higher energy photons can transfer more energy, but the question is mainly what happens with this energy in light-matter interactions.",
"A wide range of processes can occur when absorbing light. They can range from atomic to macromolecular scales. Light of very high energies can be used for photo-ionisation, wh... | [
"Yes, a higher energy photon will transfer more energy to an object and therefore heat it up more. Consequently, UV light will heat up objects more than the same amount of infrared light would.",
"Why then do we associate infrared light with heat?",
"To answer that, we must realize that all objects radiate elec... | [
"It is a good question, and the answer is going to involve a few different physics concepts. The short version is that although many wavelengths can heat something up, IR light is absorbed by anything made of water while other wavelengths might not be absorbed so well.",
"I've been learning about the photoelectri... |
[
"Does the human body and brain have a natural electromagnetic shielding?"
] | [
false
] | How does the human brain protect itself from its own interference. If I have so many electromagnetic signals being passed through my brain at once how do they not interfere? Also, if I pass a highly powered magnet over my brain why does this not induce a current and cause something odd to happen? | [
"Regarding part 2; ",
"Transcranial magnetic stimulation",
" is the use of magnetic fields to excite specific parts of the brain for use in helping with mental or physical disorders.",
"rather heavily edited from the original entry."
] | [
"There is in fact a phenomenon called ",
"ephaptic coupling",
" that is exactly what you describe. Under certain conditions, activity in one group of neurons can directly (i.e., non-synaptically) effect that of others via electric field effects. However, it's doubtful that it contributes significantly to normal... | [
"Myelin provides insulation in the sense that it prevents the charge that propagates an action potential from dissipating. It insulates the nerve by containing the charged ions that create bioelectric signals. Myelin does not function by blocking an electromagnetic field in any way. "
] |
[
"Would an extinction level meteor appear significantly brighter than a harmless meteor as it streaked across the sky?"
] | [
false
] | As in, when I see a meteor, how do I know if I should pull out my phone to take a picture or to tell my family that I love them? :-) | [
"Just to put some perspective on the numbers, when the front edge of the meteor that killed the dinosaurs first touched the ground, the back end was as high as commercial jets fly. It was 5 or 6 ",
" across. The little \"shooting stars\" you see in meteor showers are the size of sand grains, pebbles for the ",
... | [
"Well you'd probably find out first off because an extinction level meteor strike because it'd be in the news for months before it happened. Astronomers are very good at figuring out what is where, and if it will hit Earth. ",
"Next thing is than an extinction level meteor would be much much larger than your ever... | [
"Thanks for the reply Charyou-Tree...so just for clarity, the shooting stars shown, for example, in videos like ",
"this one",
", are the size of ",
"?!"
] |
[
"If a closed circuit terrarium does not allow anything with mass to enter or exit, how can the plant inside grow and gain mass?"
] | [
false
] | null | [
"2 main reasons:"
] | [
"thanks for the answer!",
"but my question was more of how does the whole system get heavier? as time passes, the whole system increases in mass even though mass is only trasnferring from the soil/fertilizer to the plant. also, energy has negligible mass, which means that it should not be able to add mass to th... | [
"Are you including air in your mass restriction? If not,that's the culprit, CO2 in, O2 out. The Carbon stays in the plants."
] |
[
"Why does silica gel absorb water so effectively, and why only water?"
] | [
false
] | I've been trying to persuade it to absorb ethyl and methyl alcohol with metal salts dissolved in it, to create potentially long-burning coloured fire fuels, but it won't have any of it, nor a few other solvents I have rattling about. So I'm wondering what is so unique about water that enables it to absorb monumental a... | [
"I usually work with proteins dissolved in water, but I imagine it is approximately the same mechanism at play.",
"So first, silica gel absorb tons of water because it has a huge specific surface area. We're talking about 800 m",
" /g of silica gel. Our lungs pale in comparison. When something gets wet, water i... | [
"Thanks for the rapid reply, I appreciate the depth of your explanation. ",
"Regarding the stuff behaving like solid water - that was why I was testing the idea with silica gel. I was hoping it'd behave as both a wick and reservoir.",
"Antifreeze, I'm not sure I want to be using, even if I could find a pure so... | [
"The fumes wouldn't be any more toxic than your ethanol/methanol flames already, I'd actually be worried more about whatever metal salts you're dissolving.",
"As for a sort of gelling material, you could try something polyethylene oxide/polyethylene glycol. Higher molecular weights are solid/powders that should ... |
[
"Help me understand storms?"
] | [
false
] | I've been seeing a lot of weird storm pics on Reddit lately, and I was wondering if someone could clue me in on what the differences are between the storms I see as normal and the storms I see as crazy/new. IMHO this looks like a , I've actually seen this type of storm in person, but then there are these crazy ones lik... | [
"The first picture you have is a time lapse of a small, isolated convective storm over water. The second picture is a squall line storm, the third picture I wish I knew more about the context of it, and the fourth picture is a flanking line of a supercell thunderstorm.",
"According to someone that posted your se... | [
"I believe that those are pictures of ",
"supercell thunderstorms",
"A supercell is a thunderstorm that is characterized by the presence of a mesocyclone: a deep, persistently rotating updraft.[1] For this reason, these storms are sometimes referred to as rotating thunderstorms.[2] Of the four classifications o... | [
"You two are fantastic!! Thanks a bunch :)"
] |
[
"How did theropods support their weight on two legs?"
] | [
false
] | There are a lot of incredibly large theropods like T-Rex, giganotosaurus, spinosaurus, etc. which seem to exceed large animals like elephants in weight, even though elephants are quadrupedal. I’d like to know how the leg bones of theropods were able to support the weight of these animals on two legs. I have read that h... | [
"The lower leg is the weak part of the leg structure. Femurs are extremely strong while tibias and fibulas are lighter. Both of those bones are required to give flexibility to the ankles and anchor muscles that move the toes. There are two approaches to strengthening the lower leg. Elephants did away with flexibili... | [
"Tubes are better at resisting bending compared to a rod of the same weight. That alone is the reason it's so hard to break a femur. Hollow femurs are a very early feature of large animals that has persisted over time. But various animals have done different things with the space in the bone. Mammals use the space ... | [
"Thank you again."
] |
[
"How hard would it be to \"solve\" Scrabble, relative to Go and Chess?"
] | [
false
] | I was just playing today when I realized how extraordinarily complex the game would be to perfectly play for a computer. A computer would have to play a move to score as many points as possible - but it'd have to also consider the tiles such a move would open up, and the probability of me holding certain tiles to respo... | [
"The element of luck and not knowing the other players letters make it impossible to calculate the next X turns and thus producing a perfect play.",
"Optimal strategies could be developed as it would be quite easy to calculate the highest scoring move by running through a dictionary. You could also implement a ce... | [
"GO is unsolvable",
"It's hard to solve, but I don't think it's unsolvable. "
] | [
"I can't really provide any exact details about the algorithms it uses, but there is a program called ",
"Quackle",
" that pretty much does the things you're suggesting. It runs through possibilities, based on remaining tiles in the bag and other things, and suggests the \"perfect move\" for each turn.",
"If ... |
[
"When and how did scientists figure out space was a vacuum?"
] | [
false
] | This sounds strange and maybe more of a history of science question but when did humans figure out that space was a vacuum, or rather that there was no air up there? Also, how did they figure it out without actually going there or being able to fly really high? | [
"Wikipedia has a description of the ",
"discovery of outer space",
" that is relevant."
] | [
"I just have to comment that yet again it seems Aristotle slowed our understanding of the natural world. In China, without Aristotle's doctrine, it took ~500 years to decide that space must be void."
] | [
"The Chinese didn't have a better understanding then the west. They were still making the same type baseless conclusions that westerners were at the time. "
] |
[
"When describing black holes in galaxies people generally say “almost all galaxies have black holes at their centers” why almost”? Are there galaxies without supermassive black holes in their centers, if so how do they form?"
] | [
false
] | null | [
"Supermassive black holes aren't critical for the formation of galaxies - they're just a small part of them.",
"Galaxies start to form when dark matter collapses into a \"halo\" - a big ball. The gravity of this concentration of dark matter causes gas to follow along and collapse into the centre of this halo. The... | [
"The mass of a galaxy, even ignoring dark matter, is much much bigger than the mass of the black hole. The galaxy is held together by its own gravity."
] | [
"No, there are some galaxies which are observed to have no supermassive black hole. M33 (Triangulum) is the third largest galaxy in the Local Group but it doesn't have a supermassive black hole. If it does have a central black hole it can be no more massive than a few thousand times the mass of the Sun."
] |
[
"Can you get sick while living in total isolation from humans and animals?"
] | [
false
] | null | [
"Yes. You could definitely still get cancer, your immune system could fail, or you could suffer from any number of adult onset genetic diseases. That said, I assume by \"sick\" you mean \"could you get an infection\" and the answer to that is still yes.",
"You carry a huge load of bacteria in your gut (and nose,... | [
"You could always take a vial of pathogens with you.. Still within the parameters of the original question :)"
] | [
"The thing about S. aureus in particular thought is that 20% of people carry it as a commensal in the nasal nares and are at increased risk to superficial infections by the organism. ",
"There are microbes absolutely everywhere, including pathogens which live in water and on foods. "
] |
[
"I see that the Pfizer vaccine starts becoming effective around day 10 (chart below I found from older post). Is this day-10 effectiveness only good for exposures that happen on day 10 any beyond, or exposures that happen on earlier days and symptoms would normally begin to show by day 10?"
] | [
false
] | [deleted] | [
"The minute after you get the vaccine is a minute less of a head start the virus has on your immune system.",
"In the real world, it's just not clinically appreciated or demonstrably significant until around day 10.",
"So, if you get the vaccine and then are exposed to COVID the next day, you are slightly bette... | [
"The Pfizer study looked at symptomatic infection—a “case” was defined as fever/cough/etc plus a positive test within four days of the onset of symptoms.",
"So going by that, the date of onset is when symptoms started—so one would assume they got infected a few days before.",
"Also it’s measured at 7 days, so t... | [
"It's pretty much impossible to test this unless you're intentionally exposing thousands of people to COVID, which is obviously not ethical. It's also going to differ per person and due to a variety of factors. It's very unlikely that the immunity \"snaps into place\" suddenly at day 10. The most we can say is that... |
[
"I've seen multiple species of snakes referred to as \"the most venomous in the world\", mainly from TV shows. What is the criteria for determining venom toxicity and is there an actual, objective, most venomous snake in the world?"
] | [
false
] | null | [
"Relevant ",
"thread",
" concerning toxicity by ",
"Staus",
"No idea what the most toxic is, but the usual way to establish toxicity of a substance is called the LD50. That's the Lethal Dose for 50% of a population, or what dosage of a toxin will kill half of the subjects.",
"The experiment goes like this... | [
"It depends a bit what you mean. Different snakes have different venom with different effects. Some are lethal without treatments, but antidotes exist. Others have very swift acting venom that means you may not have time to get to a hospital. The amount of venom they inject with a single bite also varies. Thus even... | [
"Does the amount of venom produced count into this as well?"
] |
[
"Are all things elastic?"
] | [
false
] | By elastic I mean having an elastic property. What substances or objects are never elastic? | [
"Macroscopic objects made of atoms and molecules are never perfectly rigid. They are held together by electrostatic forces, which are finite (following Coulomb's law, ",
"F = ke^(2)/r^(2)",
"). A rigid body would mean that the electrostatic force holding each particle in its place would be infinite, which is ne... | [
"Fundamental particles, like the electron, are not compressible as far as I know.",
"As far as we know, fundamental particles don't have any volume to compress, so that's not surprising."
] | [
"No... But I'm not entirely sure how you mean that.",
"All things are ",
". That is, if you apply a stress to any material then it will change shape. No material is perfectly ",
".",
"An ",
" material is essentially an object which ",
" will return to its original shape. So, if you stretch a rubber band... |
[
"Why do water and some other drinks not have calories?"
] | [
false
] | I wondered this for some time now. I don't really understand how something can not have any calories at all. | [
"calories are basically another way of saying sources of energy. Water doesn't have calories because it is simply a solvent for reactions to occur in the body. drinks such as soda have calories because of the sugar molecules in them; our bodies take this sugar molecules and break them down into smaller molecules th... | [
"Using calories to measure the nutritional content of food is sort of an odd system. The caloric content of a food is literally how much energy it would give off if you burned it, i.e. how much energy, in calories, is released when something undergoes combustion entirely. ",
"Certain compounds (like water), do no... | [
"Calories come from macronutrients - carbohydrates, fat, protein, and alcohol. Water cannot be broken down to provide energy for the body, thus have no calories. Artificial colours, flavours, carbonation, and micronutrients (like the vitamins in mineral water), among other things, also do not contain calories. Ther... |
[
"What are symmetries?"
] | [
false
] | null | [
" A thing is symmetric if it doesn't change under transformation. ",
" The short answer was kinda technical, but I assure you there is an easy way to think of this. ",
"Suppose you have a square centered at the origin and you rotate it 45 degrees.",
".png) That rotation is an example of a transformation, and ... | [
"I'll give it a shot. This isn't formal or super rigorous, but it gets the point across, which is what I think we need. ",
"If anyone sees any big problem with this explanation, please let me know.",
"There's this quantity called the Lagrangian that you can assign to a system. For simple systems, it's just the ... | [
"Is there a fairly simple (but not lacking) explanation/introduction to Noether's theorem that you (or anyone else reading this) are aware of?\nI've studied basic classical mechanics, on an first-year undergrad level, but not to the point of learning anything about symmetries, Hamiltonians, Lagrangeians and so on. ... |
[
"Why does supranormal dopamine activity in psychosis/schizophrenia not produce the subjective well-being or euphoria generally associated with dopaminergic stimulants and opiates?"
] | [
false
] | Based on some reading I did a long time ago but cannot for the life of me find, my understanding is that the popular conception of dopamine and associated neural pathways may be inaccurate. The paper I read suggested that dopamine and the reward pathway are implicated in compulsiveness, craving, and general addictive q... | [
"An overactive mesolimbic pathway produces positive symptoms in SZ and a dysfunctional mesocortical pathway produces negative and cognitive SZ symptoms. There’s also reduced glutamate CSF levels In schizophrenics and downregulation of NMDA receptors. I like to think of what would happen if you took way to much amph... | [
"There’s also reduced glutamate CSF levels In schizophrenics",
"Has this been conclusively proven? Last I checked, evidence was conflicting, and it was difficult to measure because glutamate exists in a cycle with glutamine.",
"It's also possible that NMDA hypofunction is caused by endogenous antagonists (like ... | [
"I don't have time to read the whole article, but the first paragraph says:",
"The first indication that glutamate neurotransmission might be altered in schizophrenia originated from an observation that patients had decreased levels of glutamate in their cerebrospinal fluid. ",
"."
] |
[
"Is there a reason why we use infrared light for sending data? Could we do it with any other colour wavelength?"
] | [
false
] | null | [
"Infrared light is convenient for signaling in e.g. remotes because it's a) invisible to the naked eye; b) not harmful to humans or animals; and c) is readily, efficiently produced with a light-emitting diode. You could certainly signal with other wavelengths in e.g. the visible range or ultraviolet range, but vis... | [
"We can and we do. The one that comes to mind at the moment is Plastic Optical Fiber (POF). It uses 650nm(red) light and has similar performance to cat6 copper cable. I believe that S/PDIF applications also use visible light. However in both multi-mode and single-mode fiber optic applications, an IR laser (or LED f... | [
"You hook up similar circuitry to what you currently use to detect & transmit IR but you pick a visible light diode/receiver instead of an IR one.",
"Here is an article on using visible-wavelength light for wireless data transmission."
] |
[
"How do equatorial -> polar wind patterns affect weather?"
] | [
false
] | I was in a college class introducing climate science including some of the intricacies of climate change, and an instructor mentioned that air flows from the equator to each of the poles at a high altitude level, then flows back to the equator at a lower altitude level, and that this influences local weather. The proce... | [
"So when you study this stuff in grad school, you end up learning that while the Hadley cell and Polar cell are directly observable, the Ferrel cell between the two is not. It's only seen when you average over months of data, emerging as a statistical trend rather than a bulk flow.",
"Since the Ferrel cell spans ... | [
"I guess ",
"this picture",
" from ",
"this article",
" could be helpful to you.",
"Also what is now happening in North America, is that the Arctic [polar vortex[(",
"https://en.wikipedia.org/wiki/Polar_vortex",
"] (low pressure area of very cold air on the poles) tends to be usually strong and be o... | [
"Hadley, Ferrel, and Polar Cells! That's what they're called. I could only find the east-west jetstreams, and the troughs/ridges didn't match up to what I had heard so I wasn't sure where else to look.",
"And that precipitation map matches what I was thinking pretty well. The Walker Circulation is super cool too.... |
[
"How do we know that other galaxies do not consist of antimatter?"
] | [
false
] | There are three things that you often hear about antimatter: It is the exact opposite of normal matter and when a matter-particle meets its antimatter-counterparticle, they annihilate each other resulting in the emission of a photon. Antimatter particles behave to each other just like regular matter particles do. Antim... | [
"Even though outer space is basically a perfect vacuum, it is not ",
" empty. There is something on the order of one atom per m",
" even in deep intergalactic space.",
"If there was a galaxy somewhere made out of antimatter, there would have to be a matter/antimatter boundary somewhere between them and us. An... | [
"But how do we know that mattee outnumbered antimatter?",
"You've kinda gone around may actual question. "
] | [
"I agree with the general idea of your argument, but I'm not sure there are actually measurements that rule out antimatter \"superclusters\" or some such large-scale separation... see ",
"this article",
" for example... I know some experiments (",
"AMS",
", the ",
"Exam balloon flight",
" before that,... |
[
"Can we accurately predict the behaviour of, say, a NaCl molecule by knowing the full properties of Na and Cl separately?"
] | [
false
] | I meant to say: Can we accurately predict the of a NaCl molecule by knowing the full properties of Na and Cl separately? Edit: For those interested in the philosophical implications which basically proved to me that this doesn't violate reductive physicalism: | [
"The other answers exaggerate the difficulties. Sure it is not as easy as just writing down the Schrödinger equation and solving it. Sure you have too many particles for an exact solution, but you can do loads of things. Pretty much the only thing that has an exact solution is the harmonic oscillator.",
"You can... | [
"You don't just have 2 atoms, you have 28 electrons and two multiparticle nuclei likely with dipole etc. terms. It's not that we don't understand atoms. Classical gravity is far simpler and even then there is proven to be no analytic solution to the 3 body problem. NaCl is at least a 30 body problem with much mo... | [
"The schroedinger equation is a partial differential equation not an algebraic one. Two atoms bonded to each other is a completely different Hamiltonian than adding the Hamiltonian of two isolated atoms together."
] |
[
"What factors determine how long it takes for a system to attain thermal equilibrium?"
] | [
false
] | null | [
"If conduction dominates, the initial temperature, size, thermal conductivity, density, and heat capacity. These are the parameters appearing in the ",
"time-dependent heat equation",
".",
"If convection dominates, the initial temperature, size, ambient temperature, surface area, and convection coefficient. "... | [
"How quickly energy is exchanged and how quickly/freely you can move between energy states.",
"E.g. diamond vs graphite - graphite is the equilibrium state at room temperature and pressure but diamond can't get to there without first going up in energy, so the interconversion process takes astronomical amount of ... | [
"I think the question isn't so much about overall chemical equilibrium as much as it is just a question of relative rates of heat flows, like how long it takes a Styrofoam cup of ice water in a room at ambient temperature to melt.",
"This scenario comes down to heat capacities and thermal conductivities. A few gu... |
[
"How do selective serotonin reuptake inhibitors (SSRIs) work?"
] | [
false
] | I've recently started a course of SSRIs, and I'd like to know how they work. I have a background in physical science, but know almost nothing about biology, so this (from Wikipedia): SSRIs are believed to increase the extracellular level of the neurotransmitter serotonin by inhibiting its reuptake into the presynaptic ... | [
"Neurons tend to make and release a specific neurotransmitter to communicate with one another. Between each neuron is a little space (called a synapse or synaptic cleft) where these neurotransmitters are released into (outside of the neuron=extracellular) and can bind to the neuron they are communicating with (neu... | [
"So serotonin is a neurotransmitter-it is a chemical that's released from the end of one neuron that is bound by a receptor on the second one, thus sending a signal. In order for the system to reset and send another signal, the excess neurotransmitter has to be taken up quickly back into the first neuron. SSRIs w... | [
"Basically, when you have a synapse there is a chemical trigger that will move from the presynaptic membrane (the end of the first synapse) to the postsynaptic membrane (the start of the second synapse). ",
"Normally, this works by an action potential (think electrical signal) travelling down an axon (what makes... |
[
"Is anything truly random in nature?"
] | [
false
] | For example,if I flip a coin,we like to say it has a 50-50 chance,but the side is determined by how much force and where I apply the force when flipping,gravity acceleration and wind.therefore you could say flipping a coin is not a random event. Is anything in nature truly random? | [
"Genuine question --",
"Why do we suppose that this represents true randomness, rather than assume there's just some variable to the experiment we don't comprehend?"
] | [
"Genuine question --",
"Why do we suppose that this represents true randomness, rather than assume there's just some variable to the experiment we don't comprehend?"
] | [
"Not just a genuine question, an awesome question. That is precisely the idea behind ",
"hidden variable theory",
". A very clever result known as ",
"Bell's theorem",
" has shown any hidden variables would have to be \"non-local,\" meaning (as I understand it) actions at one location can have impacts at... |
[
"[Biology] Why is ATP never dephosphorylated twice in metabolic pathways?"
] | [
false
] | Wouldn't turning ADP into AMP produce just as much energy as turning ATP into ADP? | [
"Your premise is incorrect. ",
"There are several ADP-dependent kinases",
". They just aren't as common.",
"Everything everyone else in this thread mentioned points to the answer about why ATP is the more common P donor, but the thermodynmaics change in thermophiles, giving some organisms a path for selecti... | [
"Stereochemistry. ",
"Remember, all these pieces are physical...ATP has a size and a shape, and so do the proteins and other stuff it interacts with; it all has to fit together just right or it just doesn't work.",
"Picture an enzyme...a kinase, for example. Any enzyme/pump/whatever would work, but let's stick ... | [
"Yeah, the hydrolysis of ADP to AMP has about the same free energy change as ATP to ADP. A current theory is that the three phosphate groups is an evolutionary relic based on the starting conditions of life. The formation of nucleotide bases and cyclic phosphates is plausible from abiotic beginnings, which have bee... |
[
"Why is it easier to remove the shell of a boiled egg, if you put it in cold water for a while after boiling it?"
] | [
false
] | [deleted] | [
"A close look a the shell of an egg reveals thousands of tiny pores through which carbon dioxide and moisture in the egg may exit over time, allowing air to enter. As a consequence, the air pocket developed during laying increases in size as the egg ages. During the boiling of an egg, the increase in temperature ca... | [
"Boiled eggs also peel more easily if the eggs aren't \"fresh\". I don't mean non-edible, just that a freshly laid egg is hard to peel no matter what, but wait a week or two and cook them - easily peeled."
] | [
"It stops burning your fingers which was causing you to fumble..."
] |
[
"Why did my beer just freeze within a 20 second period?"
] | [
false
] | [deleted] | [
"Cool, I've never gotten that experiment to work! The beer was at a temperature where, at atmospheric pressure, it would freeze, but at the higher pressure in the bottle, remained a liquid. When you open the bottle and release the pressure, the beer is supercooled, meaning it is still liquid but is below its free... | [
"No, this is probably not completely correct. It is, as others have said, liquid water that has become supercooled. The temperature is already below the freezing point, it simply did not have a nucleation site to begin the transition into a solid crystal structure.",
"The OP would have had the same result if inst... | [
"I don't believe the phenomena isn't ",
" due to a supercooled liquid. I'll give you another theory which couples with the supercooled liquid theory, and maybe someone else can explain it much better. I'm on my way out the door right now.",
"Although supercooled liquids certainly do exist, the idea behind a sup... |
[
"Curious question about female ovulation"
] | [
false
] | So women have ovulation cycles. Resulting in periods. And they have two ovaries. So... I'm a college grad (guy) so I feel awkward to ask a biology professor. | [
"Speculation is not appropriate in AskScience. Please read the guidelines on the right."
] | [
"The reason speculation isn't appropriate is that people come here to read answers to the question, not guesses. It may be harsh, but it's efficient; it's also the way the /askscience community wants it. Don't judge bro, that's just the way it is.",
"As ents, we should respect their customs as they respect ours. ... | [
"Interesting points mentioned in the article by cdcox",
"In six cycles out of 205 (3%), ",
"(",
") The more you know.",
"[..] the data suggest that in normally fertile women the side of ovulation, the length, and the hormonal profile of a given cycle are independent of the side of ovulation in the previous ... |
[
"I have had visions throughout my 18 year life of extremely early events including the lobby of the hospital I was born in. I recently revisited the hospital after 18 yrs and it was as I recalled it to be. How/why is this possible?"
] | [
false
] | null | [
"This sort of thing is fairly common. You had been told about those places, possibly very early in life, or you heard someone else talking about it, and forgot hearing about it, but didn't forget the description. "
] | [
"Hmmm. Makes sense."
] | [
"Also, photographs.",
"Edit: to explain, I mean family photos or newspaper images."
] |
[
"Rechargable batteries: How are they made?"
] | [
false
] | My two main questions are these: when they are manufactured, do they already have charge, or do they need to be charged before shipping or integration into a device? Also, what about them is chemically/physically different from regular disposable batteries? | [
"Depends on the battery. ",
"Ni-MH: Fully charged at the factory, but the materials in this battery type cause the battery to quickly lose it's charge over time. The amount of charge it loses everyday is always a small percentage of the current charge. So by the time you buy it and take it home, it could have... | [
"What about the toxicity of Lithium-Iron-Phosphate? Can they be thrown away?"
] | [
"LiFePO4 and LiMnO2 electrodes are pretty environmentally benign; you might be able to dispose of them in ordinary landfills depending on the other additives included in their cells, unlike NiCd, NiMH, or many LiCoO2-based batteries (Ni is a carcinogen, and is used as a dopant along with Al in modern LiCoO2 materia... |
[
"Why are there no Chihuahua or Great Dane sized cats?"
] | [
false
] | Why is there less variability in cat breeds as compared to dog breeds? If there is selective pressure in a village or area to have a huge or tiny dog, why wouldn't the same pressure apply to cats? | [
"Yes, in fact. \"The most common and most likely theory is that Chihuahuas are descended from the Techichi, a companion dog.\" ",
"http://www.akc.org/breeds/chihuahua/history.cfm"
] | [
"Yes, in fact. \"The most common and most likely theory is that Chihuahuas are descended from the Techichi, a companion dog.\" ",
"http://www.akc.org/breeds/chihuahua/history.cfm"
] | [
"Yes, in fact. \"The most common and most likely theory is that Chihuahuas are descended from the Techichi, a companion dog.\" ",
"http://www.akc.org/breeds/chihuahua/history.cfm"
] |
[
"A geology/geography question via picture."
] | [
false
] | Edit. It is in the Stone Forst of . I found the image in | [
"This is almost certainly an example of karst. A similar thing is found in China; see ",
"http://en.wikipedia.org/wiki/Shilin_(Stone_Forest)",
" and in ",
"Madagascar",
".",
"Edit: Added Madagascar."
] | [
"Karst erosion takes place in regions underlain by limestone, which is principally made of the mineral calcite. Pure rain water does not effectively dissolve calcite, but if the water is even slightly acidic, it is a very effective agent of chemical erosion. Rain water becomes acidic by dissolving carbon dioxide fr... | [
"As far as I know 2 options",
"Karstic erosion due to acidic rain on limestone’s ",
"http://en.wikipedia.org/wiki/Karst",
" (I have never seen anything this heavily eroded/pronounced but it should be (as far as i know) theoretically possible)",
"The other is the combined effects of wind and rain on sediment... |
[
"Is the universe in a false vacuum?"
] | [
false
] | null | [
"Likely not, because we are here talking about it. this is one of the physics questions that edge in to philosophy because there is no known way to falsify the statement \"We are in a false vacuum and it has collapsed at some point outside our light cone\". It's not really a question worthy of scientific inquiry be... | [
"What do you mean by \"stronger\"?"
] | [
"You have so many misunderstandings of what is going on in the paragraph you just typed. First and and foremost, vacuums do ",
" exert a force, ever. This is a frame of reference issue for you. There is [mostly] nothing in a vacuum; and nothing has a hard time doing something.",
"...beaker of water... put a ... |
[
"While hallucinating, is the brain rendering extremely accurate parts of reality on its own?"
] | [
false
] | As a computer science major, the idea of this fascinates me. While someone is hallucinating, is the brain actually rendering bits and pieces of reality completely on its own? I'm guessing it does some kind of lazy rendering, like omitting the details of the back of someone's head, for example. Is there research being d... | [
"The simple fact is we have no idea. However, it seems far more likely that the neural mechanisms of hallucinations should be thought of as a perturbation of normal processes. The theories that usually get thrown around are abnormal spread of neural activity (i.e. activity that codes for one thing \"leaks\" into ot... | [
"There is, however, ",
"some research",
" done on hallucinogens, but it's very preliminary. Carhart-Harris found dissociation between task-dependent and resting state networks (in non-psychedelic states, these are inversely correlated)."
] | [
"Short answer: yes, but that's nothing special.",
"Longer answer: The brain constantly \"renders\" everything you see. One of its most basic functions is to predict your entire life, everything you see, hear, feel and even think. Taking a familiar walk around the park? Your brain conjures previous memories of thi... |
[
"Does alcohol actually result in increased fat storage by disrupting the body's tricarboxylic acid cycle?"
] | [
false
] | So my understanding of chemistry in general is fairly limited, so hopefully the chemistry people can chime in and help me with this. I know that when the TCA occurs, the process of dehydrogenation takes place, which requires the action of the co-enzyme NAD (as it's a redox reaction). I also know that as ethanol is bein... | [
"EtOH refers to ethanol, or drinking alcohol. TCA refers to the citric acid cycle."
] | [
"I'm more of a layman... What do these acronyms refer to?"
] | [
"I'm more of a layman... What do these acronyms refer to?"
] |
[
"Is there a reason why sexual activity/desire with a long-term significant other increases during times of travel or vacation?"
] | [
false
] | [deleted] | [
"IMHO it's because you're not surrounded with your daily responsibilities. Stress is a major libido-zapper"
] | [
"I don't have the scientific evidence to back this up, so I am prepared to be downvoted to oblivion, but...",
"I remember (when me and my ex were going through counseling) being told to rent a room to spice things up. Reason being - staying at home reminds one of their responsibilities and other stresses related... | [
"This makes sense. Thanks for the replies."
] |
[
"Some clarification on looking at an object being pulled into a black hole"
] | [
false
] | Forgive me if this has been asked before -- I tried my best searching. I've always heard the explanation that an external observer will never see an object fall into a black hole. In fact, they would see an object frozen at the event horizon. If this is true, and we could somehow travel near a black hole, wouldn't it j... | [
"You never observe an object entering the event horizon. You observe an object simultaneously getting very close to it and very dim, to the point that it disappears. This all happens pretty quickly.",
"To a naïve, casual observer, it might look approximately like the object fell into the black hole, yes. But if y... | [
"Things falling into a black hole are also redshifted and dimmed as they approach, so they fade from view. You can calculate the length of time it takes to fall in, and it's fractions of a second from a starting point fairly close to the event horizon - see ",
"this page",
", about halfway down (\"Now, this led... | [
"The link you sent said: \"The reason is that as things get closer to the event horizon, they also get dimmer. Light from them is redshifted and dimmed, and if one considers that light is actually made up of discrete photons, the time of escape of the last photon is actually finite, and not very large.\"",
"So t... |
[
"What is the most common state of matter on our planet?"
] | [
false
] | Question from a 10 year old that I just couldn't answer. We are looking at the problem by volume. I feel that it would not be gas as the atmosphere is a very thin sheath relatively speaking. I know people are going to use the line that 70% of the earth is water but that is not true. 70% of the surface of the planet... | [
"r/AskScience",
" is not a place for jokes."
] | [
"According to the wikipedia article on ",
"mantle",
" this makes up the majority of earth's volume and is technically solid (which is funny because I always thought it was liquid). "
] | [
"Yes, this is correct. Most of Earth is solid, by a wide margin. Only the oceans, the outer core, and a small percentage of the mantle is liquid. Only the atmosphere and small percentages of magma is gas. Much much more is solid.",
"There is some debate as to what % of the mantle is liquid on average. It could be... |
[
"When is the next Galactic year?"
] | [
false
] | [deleted] | [
"Nope - the Galactic Year recordings started from modern times when the measurement was invented. It wont be 1 Galactic Year for another 225 million years. ",
"P.S Brian Cox is amazing. "
] | [
"Scientifically speaking, a \"year\" is just the ",
" that an orbit takes, and doesn't have a particular starting point or ending point except for the arbitrary ones that we define. The point that marks the beginning/end of our Earth years is purely invented, and isn't even consistent across all calendars.",
"I... | [
"Thank you very much :) ",
"P.S I'm in love with him"
] |
[
"Where did the massive amount of the sand that forms the Sahara Desert come from?"
] | [
false
] | null | [
"From the erosion of the underlying rocks. Also, sand formation got something of a head start, as there were large scale sand reservoirs in fluviatile systems before the desertification really went haywire. Some of those fluviatile deposits got remobilised in eolian dunes once the rivers went dry."
] | [
"Certainly!"
] | [
"I use Google's Chrome browser and it sometimes works brilliantly for decrypting those jargon-heavy explanations. Double click on a word, (like \"fluviatile\") and select \"Search Google\" and it immediately pops up a definition. (Related to rivers.)",
"So, the tough part of what Gargatua13013 said is, the rive... |
[
"We often hear about the fastest land animal on Earth being the cheetah. But what would the fastest land animal be over a distance of a marathon? How high would the top human runners rank?"
] | [
false
] | null | [
"You see the meme around all the time that humans are the best, but it's not exactly true. Yes, there have been cases that humans have beaten horses. There have also been many more cases where horses have beaten humans (while carrying humans!). I don't think it's very accurate to say that humans are the top beca... | [
"Yes, there have been cases that humans have beaten horses. There have also been many more cases where horses have beaten humans (while carrying humans!).",
"As prominent example, the Welsh ",
"Man versus Horse Marathon",
" has been won by humans* twice - the other 38 times a horse won.",
"*not carrying a h... | [
"There's a lot of evidence to support that humans used to literally run other animals to death as a hunting technique. Basically the prey (probably a gazelle or antelope) runs away super fast but the human(s) keep chasing them slowly but surely and after a bunch of quick dash escapes the prey is too tired to run an... |
[
"What happens to an ant from one colony when it is transplanted miles and miles away near a different colony?"
] | [
false
] | [deleted] | [
"Depending on species, it would probably be killed if it tried to join another colony because it doesn't have the right scent:\n",
"http://en.wikipedia.org/wiki/Ant#Cooperation_and_competition"
] | [
"There is one species that will likely intermingle with other colonies. That is the Argentine ant. They just join up with other ones. \n",
"http://en.wikipedia.org/wiki/Argentine_ant"
] | [
"Some ants actually ",
"take slaves",
". But generally, an ant away from it's colony will be killed by other ants."
] |
[
"Would global cooling create more land? If so, how much more land would be available before the whole earth freezes?"
] | [
false
] | My hypothesis is based on the reverse of the polar ice caps melting. If there was a global cooling, then I imagine the polar ice caps would grow in size (more water freezes) and the ocean level would get lower, baring more land. | [
"Welp, your hypothesis is born out by historical precedent. During the Pleistocene glaciation, a mere few tens of thousand years ago, the continental icecaps reached just south of the Canada/US border and sea levels exposed large parts of the continental margins, including the ",
"Beringia",
" landbridge which ... | [
"The question is not stupid. ",
"The thing is that the overwhelming majority of the new ice cover accumulates over land. If we stick with the last glaciation as a model, you're covering ",
"pretty much the whole of Canada all the way down to Minnesota and Manhattan with 2-3 km of ice. Also northern Europe and S... | [
"Definitely not a specialist, and probably a stupid question, but I'm curious!",
"With ice being less dense than water, would it not displace more water than it 'stores' and actually increase the ocean depth to cover land over anyway? "
] |
[
"Will eating \"thermogenic foods\" have any significant impact on weight loss?"
] | [
false
] | My mother decided that the way to lose weight is to start eating "thermogenic foods", because of some article on a website she saw ( ). They claim that "such foods play an important role in weight loss." Is it really important? Will it make any noticeable difference? | [
"Will it make any difference? That depends. Thermogenic foods can help increase the metabolic rate above basal limits, however it is only by a small amount and it alone won't be sufficient to cause significant weight loss, at least in a noticeable amount of time. However eating foods that increase the metabolic rat... | [
"Thank you, it is as I suspected then. They claimed it was a recipe for a \"diet juice\", like some sort of lose weight fast scheme (3kg/week, they said)."
] | [
"3kg a week is a bit much, especially in the absence of exercise. One really should not lose more than 1-2 kg a week."
] |
[
"If space isn't really a vacuum, could we make engines that pull/push the matter to propel itself?"
] | [
false
] | [deleted] | [
"Yes you could build a ",
"Bussard ramjet"
] | [
"Theoretically ",
". How are you supposed to propel something using the Casimir effect? You get equal and opposite forces.",
"OP: Virtual particles ",
" real things. They're a mathematical tool. "
] | [
"Theoretically, yes - ",
"http://en.wikipedia.org/wiki/Casimir_effect",
"But, these forces would be extremely small, and hence it'd be very inefficient.",
"Also, solar sails are super cool - based on effectively reflecting photons to gain their momentum, in a vaguely similar way to a wind-sail."
] |
[
"Okay, after watching the Olympics its hard not to see the racial pattern in different events. Is there a scientific explanation for this?"
] | [
false
] | The swimming events are mostly white and the running events are mostly black. Is there scientific evidence to support that either race is better at that sport. I heard that white people tend to be oilier and black people have a extra tendon. Is that true? | [
"You are partially correct, there is a racial divide between the sports, however, it doesn't have to do with any of your assumptions. A couple years ago, scientists found that the divide had to do with centre of mass of each individual. Now I can't find the actual study, however I can show you two articles written ... | [
"Swimming: ",
"A) guess which nations actually have swimmingpools of sufficient size to train",
"B) guess which nations have \"free time\" to devote to something as stupid as swimming for fun.",
"C) guess which nations have the largest percentage of its population with mandatory swimming lessons for kids",
... | [
"See also weightlifting.",
"Even though weightlifting is arguably one of the sports where inherent genetic ability plays the greatest role (strength can be trained, but power, i.e., the ability to recruit motor units quickly, is almost totally genetic), Olympic performance in weightlifting has varied greatly over... |
[
"In light of the Miami face eating story I started to wonder... Is there any scientific possibility of a virus mimicking a zombie apocalypse style virus?"
] | [
false
] | Like any other post-secondary student with too much time on his hands, I often wonder about the possibility of a zombie apocalypse. I know that a lot of different shows/movies try to create some scientific explanation (28 days later = rage virus, the walking dead = brain dying with the exception of the brain stem) but ... | [
"Parasites can affect behavior, so that's at least partially plausible.",
"The main unscientific thing with zombies is how tough they are. You walk around rotting like that and you'll pretty much fall apart completely soon. I mean, you could theoretically lose all ability to respond to pain and keep coming afte... | [
"Hypothetically, yes. ",
"There are two main factors that would determine something like this happening. One is what part of the brain is hit, and the second is the specificity of the virus for that area.",
"In regards to the first, there are a couple of places that the brain could get that could result in beha... | [
"Rage zombies, (and all zombies to an extent) seem unrealistically depicted to me because they always seem to be able to differentiate infected/dead from not infected/dead.",
"Surely a rage zombie epidemic would simply result in all the infected killing each other in the street, seeing as they are 1) More visible... |
[
"Why is a bone marrow transplant not always 100% effective at curing blood cancers?"
] | [
false
] | I was reading earlier today about the kinds of ailments that bone marrow transplants are used to treat (as I am thinking about signing up on the registry to donate), and I noted that in the case of leukaemia, chemotherapy or radiotherapy is used to completely destroy the recipient's immune system first. However, whilst... | [
"TLDR - Sometimes there is a rejection of the transplant or the person's own cancerous cells coming back (relapse).",
"For leukaemia the malignant bone marrow cells are killed off with chemotherapy and then replaced with donor cells. Sometimes there is a failure of the transplant or the person's own cancerous cel... | [
"The answer to your question is probably going to depend on the disease in question.",
"For the treatment of leukemias, as ",
"u/SillyStallion",
" points out, some malignant cells may remain after treatment leading to relapse.",
"For people (particularly small children and infants) given bone marrow transpl... | [
"Nope not mistaken - I've just got a job specifially with this. It's novel therapy and still very much in early human trials. CAR-T itself has only really become mainstream these past couple of years",
"For example injecting Reblozyl (luspatercept) regulates the maturation of red blood cells. It does this by bloc... |
[
"What part exactly of a computer chip contains silicon?"
] | [
false
] | I tried looking this up, but can’t find what I’m looking for. Is the silicon part of the metal looking wires, or is it the actual green board itself? | [
"The chips are inside protective packages — usually black plastic with wires around the edge and some printing on top, sometimes a brownish ceramic, occasionally metal, depending on a lot of factors. (There are tons of different shapes of chip packages.) It's fairly rare for the actual chip to be exposed, because t... | [
"If you want to see the actual chip inside the black package, look at a ",
"uv erasable eprom",
". These are special packages which allow uv light to erase a memory chip, but incidentally let us see the chip inside the package. The chip is mostly silicon."
] | [
"The actual integrated circuit, also known as the \"die\". This is usually in some sort of packaging to both protect the die and hold the connecting wires in place.",
"Most desktop computer CPUs have the die underneath the metal heatspreader, with a thermal compound between them. Some enthusiasts \"delid\" the CP... |
[
"How is it possible radio waves can potentially reach other planets years from now but I lose signal to my local radio station after driving 50 or so miles away from it?"
] | [
false
] | null | [
"Signal power and a difference in decoding objectives.",
"All point-to-point communications are governed by the ",
"signal-to-noise ratio",
" at the decoder. EM waves follow the ",
"inverse-square law",
" in terms of signal power. For an intuitive understanding, consider omnidirectional transmission. The ... | [
"There are a number of differences:",
"You:",
"Aliens:"
] | [
"You lost the signal because your antenna is too small, the radio waves are still there."
] |
[
"How do we know that quarks are fundamental particles (don’t have a substructure)?"
] | [
false
] | null | [
"We are not sure and there are searches for hints of compositeness. It is unlikely, however. Typically you expect to see a substructure before the involved energy reaches the rest energy of the particle. You see that an atom has a nucleus and electrons with a few electronvolts of energy (ionization), you see that t... | [
"Would a fifth force, sort of a QCD on steroids, be able to create a confinement so strong that the results we observe be produced?",
"I'm mainly thinking of a force that gets stronger with distance similar to the strong force. Sorry if this is vague, it certainly is a call for educated speculation. "
] | [
"Well, despite confinement you can break up a proton with GeV energies. You would expect the same for quarks. So we need constituents with at least TeV of mass - bound so tightly that the total energy is just a few MeV (for up/down). That would be very strange fine-tuning."
] |
[
"When I see stars after screaming, do they come from my retina, the optical nerve, my brain or somewhere else?"
] | [
false
] | I hope you understand what I mean by seeing stars - they're the same glowing, tumbling dots you might know from getting a knock on the head or jumping from a high place. I've heard that mechanical shock and vibration can influence some nerve cells (is that true? how does it work?), but which ones are responsible in thi... | [
"I believe you're referring to",
" phosphenes",
". Low blood pressure can be a factor. I'm guessing that oxygen and/or blood restriction could be involved. "
] | [
"Right, so when you scream, you're probably either excited or in distress, both of which increase your blood pressure and heart rate. By doing this, you can set off the rod and cone cells in your eyes, as they send signals once they receive enough energy, whether it be from a light source, or a mechanical source (... | [
"It depends on the situation. Mechanical force can cause you to see stars because it triggers the activation of your retina which in turn makes signals travel to the optic nerve and brain. But another way is if, ie; you bump your head (hard enough), then you've probably \"irritated\" the occipital lobe, which is th... |
[
"Tabby's Star, KIC 8462852, the one with the unusual dimming, is it possible that it is something odd shaped that is between us and the star that is getting closer? Is there any obvious reason to rule out that it is something getting closer?"
] | [
false
] | New research shows that it is in fact dimming over the last 4 years: (Unlike the previously idea, widely refuted, that it was dimming over the last 100 years). | [
"Well, let's see what angle the star makes in the sky! The angle in degrees is equal to its diameter divided by the distance*2pi. Converting into arc-seconds, we get 0.0479 arc-seconds. ",
"The star dimmed by 1.45x per century. Which means that whatever is approaching us, has not eclipsed it. The mass of whatever... | [
"Also remember that the Earth is going back and forth in its 186 million wide orbit every year and the brightness variation of Tabby's star isn't affected by the Earth's orbital position, so whatever would be blocking the light has to be uniform over some proportion of 186 million miles (depending on how far away i... | [
"Side question: one of the reasons put forward against this being an alien megastructure is the lack of waste heat. But I don't understand why the proposed explanation of a cometary cloud causing dimming wouldn't ",
" emit heat. Wouldn't cometary matter be heated up by the star and radiate heat just like a hypo... |
[
"Is it possible for a species to have an evolutionary trait that wasn't a result of survival of the fittest? Essentially just a trait that tagged along for the ride as the generations went on?"
] | [
false
] | null | [
"Survival of the fittest is a loose term.",
"All traits are the result of evolutionary processes working; but that does not imply that all results are the ‘fittest’.",
"Any mutation that does not kill the individual and allows breeding may be continued for some time; over time useless (doesn’t help survival or ... | [
"Yes all the time. Basically any trait that occurs for whatever reason and doesn’t have any affect on a species ability to reproduce can be passed down. Evolutionary driven traits occur when the traits help a species reproduce at a higher rate than those without the trait. On the extreme the trait monopolizes the m... | [
"Yes that’s my point. It’s a random trait that didn’t effect reproduction"
] |
[
"When fish look out through aquarium glass, what can they see?"
] | [
false
] | When I look into a fish tank, the sides appear mirrored, but the back is clear. Sometimes the fish appear to be attacking, or swimming with, their own reflections; what do they see? Also, is the vision of tropical fish sophisticated enough that they could perceive individual humans, or do they just see motion? EDIT: Th... | [
"When looking outward at a flat tank side, there’s a ",
" determined by the refraction indices of the air, glass, and water. This angle would define a circle which would always be the same apparent size and direction as the fish moves (much like a rainbow). Within this circle, the fish would see a fisheye view of... | [
"The circle would be like a rainbow in the sense that a rainbow always takes up the same angle of your field of view, and always appears to be centered on a point opposite the sun—it doesn’t change its apparent size or direction as you move like ordinary objects do.",
"By “fisheye view” I mean the view you get fr... | [
"This is the kind of answer I was looking for, but I'm a little bit lost by the rainbow analogy; also, when you say that it would be a fisheye view, is that because of the aspheric distortion of the fish's lens, or some optical property of the tank?"
] |
[
"What do the chemicals in Fracking do?"
] | [
false
] | Why do they need all the chemicals? Can't they just frack with regular water? | [
"Some of them are surfactants, or in other words, soaps. The water really don't want come in contact with oil-soaked rock, so pure water would not enter the smallest cracks. As the sand is carried by the water, this means that the sand would not enter the smallest cracks, and they would collapse once the pressure w... | [
"The chemicals are used to better break through the rock where the water would be inefficient or unusable. Source: ",
"http://fracfocus.org/chemical-use/what-chemicals-are-used"
] | [
"Some fracking fluids are mostly water and sand, with a little bit (<1%) of chemical to help out the process depending on the formation. Some have no(or very little) water in them at all and are hydrocarbon based. Without the chemicals, many of the fractures that are formed (via the pressure increases) would simp... |
[
"On average, how much more do people actually eat when they purchase an all you can eat meal vs a regular one?"
] | [
false
] | null | [
"There are several papers on this topic. They don't exactly answer your question, but at least they give a hint.",
"paying for the buffet meal after eating reduces sushi consumption by about 4.5 units, as compared to paying before eating.\n",
"Source",
"A field experiment at an all-you-can-eat pizza restauran... | [
"Super interestig. Great work!"
] | [
"I think this paper is relevant in this context:",
"https://www.ncbi.nlm.nih.gov/m/pubmed/15761167/",
"RESULTS: Participants who were unknowingly eating from self-refilling bowls ate more soup [14.7+/-8.4 vs. 8.5+/-6.1 oz; F(1,52)=8.99; p<0.01] than those eating from normal soup bowls. However, despite consumin... |
[
"Can whales see in front of them?"
] | [
false
] | This picture struck me. His or Her eye is just so.. piercing, knowing, alive But it made me wonder, can it see the diver that's right in front of him/her? I read that some whales eyes can bulge out to watch squid enter their mouth (toothed whales obviously) | [
"They likely have a blind spot a little beyond the snout but not much further. Its not uncommon for animals to have eyes on the sides of their heads rather than the front. This is usually seen in herbivores as it gives them a almost 360 degree view (better for spotting predators).",
"The whale probably compensate... | [
"Cetaceans, which include whales, dolphins and the such use echolocation to become aware of their surroundings. The whale's forehead actually narrows this echolocation into a beam with its forehead, so while the whale may not have actually seen the diver, it definitely would know he was there in front of him. (I le... | [
"It is important to clarify that most large whales ",
" use echolocation because most large whales are baleen whales (mysticetes), and only the toothed whales (odontocetes) can echolocate.",
"The whale in the picture is indeed an odontocete - a sperm whale, the only odontocete that approaches the size of the gr... |
[
"What actually determines the half-time of a radioactive isotope?"
] | [
false
] | Do we actually know what determines the half-time of a radioactive isotope? I tried to ask my natural science teacher this question, but he could not answer it. Why is it that the half-time of for an example Radium-226 is 1600 years, while the half-time for Uranium-238 is 4.5 billion years? Do we actually know the fact... | [
"It's different for each type of decay, but we have a good idea of how each type of decay works.",
"For decays where something is simply emitted without any new particles being created (alpha, nucleon emission, cluster emission, and spontaneous fission), the simple model is that the emitted particle is \"pre-form... | [
"thank you for that explanation! ",
"It seems you must know a lot about this stuff. Quite funny how you inserted the just in this sentence.",
"You ",
" come up with some operator that represents the electromagnetic transition, use some approximation of the nuclear wavefunction, and calculate the decay rate fr... | [
"You can try, but the fundamental theory underlying nuclei is quantum chromodynamics (QCD), which is a strong-coupling theory at nuclear energies. A large coupling constant means you can't work out the results using perturbation theory. Rather, you have to use immense computational power to work out the results of ... |
[
"If someone is heterozygous for sickle cell anemia, are 50% of the Hb molecules in red blood cells \"sickle\" Hb?"
] | [
false
] | Or are 50% of red blood cells "sickle"? And how does this help fight against the malaria plasmodium? | [
"The Sickle Cell gene is incompletely dominant with the wild type gene. That means that both will be expressed and will create an intermediate phenotype. One who is heterozygous for the Sickle Cell gene is considered to express the Sickle Cell trait, but is not suffering from Sickle Cell Anemia. A heterozygous pers... | [
"And how does this help fight against the malaria plasmodium?",
"A relevant paper on this topic",
"Basically plasmodium, after infecting a red blood cell as part of its life cycle, hijacks RBC actin (a naturally occurring cell-strucure protein), to help it transport a protein of its own (adherin) to the RBC sur... | [
"When a heterozygous situation allows for the highest survival rates (sickle cell homozygous has a lower survival rate, as does homozygous normal due to diseases in certain regions) it's called over dominance. One of my favorite words and tidbits of info from biology."
] |
[
"What causes the arm soreness after COVID-19 vaccination?"
] | [
false
] | null | [
"Vaccines contain antigens that induce an immune response capable of providing specific protection from disease. Individual vaccine antigens induce innate immune responses that may differ qualitatively or quantitatively according to the vaccine composition, but that induce a good adaptive immune response. ... These... | [
"So many people saying \"I got this side effect because...\", dude it is just your body reacting in its own way to a vaccine, everyone there is no evidence linking someone's side effects to a vaccine and its effectiveness."
] | [
"There's a small amount of pain from the tiny damage done by the needle into the muscle. But also the vaccine can trigger inflammation at the site of the injection, which suggests the vaccine is starting to activate your immunity."
] |
[
"At what point is a particle too small to cast a shadow?"
] | [
false
] | null | [
"Depends on what you define a shadow to be. Electron microscopes technically generate an image by collecting data on a microscopic object's \"shadow.\" Electron microscopes can expose the shadows of individual molecules. (You can Google images of this.)",
"If we limit ourselves to observing a shadow due to visibl... | [
"Quantum-mechanically, a shadow is destructive interference of the scattering amplitude at forward angles (behind the scattering site), although colloquially one would assume that you’re talking about visible light being blocked by macroscopic objects. But really whenever something is scattering off of something el... | [
"....eli5?"
] |
[
"Could the language i've spoke growing up influence on how my voice sound?"
] | [
false
] | Could the way i use my vocal chords scar, or develop them so my voice would sound totally different if i grew up speaking another language? | [
"The answer to your question is mixed, and really depends on what you mean by \"voice\". When a speech-language pathologist (aka speech therapist) refers to voice, we generally view it as breaking down in three main aspects: vocal quality, intensity/loudness, and pitch. In turn, these aspects are controlled by thre... | [
"Is your question geared towards \"If I speak X language today, but grew up speaking Y language instead, if I were to learn X language would it sound the same as how I sound today?\"",
"Probably not. The language you learn growing up has an influence on how your facial and vocal muscles develop. For this reason i... | [
"I don't know what exactly the mechanism is, but people do end up having problems pronouncing certain sounds if they don't use them during adolescence/before puberty. This is the reason many non-English speaking countries have begun teaching children English at much lower ages. Just since I was in school, the age f... |
[
"Can humans taste water? Does water have taste? What are we tasting when drinking water?"
] | [
false
] | Hello Askscience community, I gave some advice earlier, well now that advice feels like non-information/bad information, so before I ever give said advice again I am curious as to: Can humans taste water? Does water have taste? What are we tasting when drinking water? Thank you! | [
"Pure water, that is H2O, doesn't have a taste that humans can detect. What you taste when you drink water is dissolved solids in the water. Tap water has chlorine and fluoride added to it, plus assorted salts that make it through the purification process. Most bottled water is usually just filtered tap water. "
... | [
"Take a look at a bottle of Dasani some time. It mentions that the water is RO Purified or something like that - it means purified through reverse osmosis. This process removes almost all of the ions (salts) that are in the source water. The chemists at Coca-cola realized that totally purified water with no salt... | [
"Sorry. That's ",
"horse shit.",
" "
] |
[
"Can two people at different inertial frames (skewed light cones relative to each other) communicate information to each other about events outside of their respective light cones?"
] | [
false
] | null | [
"That would require instantaneous communication. The light cone represents time as well as light, so the communication they send would only follow the same cone. They also cannot see events outside their respective light cones, so it's a no all around I'm afraid."
] | [
"If A is in the past light cone of B and B is in the past light cone of C then A is also in the past light cone of C. You cannot go faster than light by installing a relay."
] | [
"The position of your light cone is the same in all reference frames. If you communicate information to someone else, the entirety of your past light cone at the time you sent that information will be within their past light cone at the time they receive that information."
] |
[
"Does Mars have Quakes?"
] | [
false
] | I know there are no oceans on mars, but is plate tectonics or any thing else at work that might cause quakes? | [
"(for this post, I'm not counting quakes from meteor impacts as \"seismicity\" - it would be unreasonable to assume there are none of those...)",
"The bad news: we don't know yet - Viking had a rather unsensitive seismometer which picked up nada over a few hundred days, so: no significant data. Some imagery shows... | [
"but are plate tectonics [...] at work?",
"On Mars, no. Its core has long since become too cool to drive plate tectonics. I can't recall whether it's thought it had plate tectonics before; it certainly had plentiful volcanism.",
"As far as I know, Earth is actually the only planet with plate tectonics - Venus e... | [
"If we don't have seismic instruments on any planet but Earth, then how can we infer that how solid or fluid the planet is without being there?",
"This is all pretty fascinating stuff."
] |
[
"How did Einstein connect time and gravity? What would one have to do with the other in mathematic calculations?"
] | [
false
] | null | [
"I'll give you a short answer and point you towards the related Wikipedia articles for more.",
"Einstein figured out that if the speed of light is ",
"constant",
" no matter what, then the ",
"rate at which you see time pass",
" for something depends on your velocity relative to that thing. He first figu... | [
"I think the question should be phrased a bit differently. Einstein did not connect gravity and time, Einstein proposed a link between space and time. According to ART, gravity is not a fundamental force but rather a consequence of the \"shape\" of spacetime."
] | [
"I've heard that in the years prior to 1905 when Einstein was a patent clerk, there were dozens of applications filed for the synchronization of multiple clocks, which got him thinking about what it meant for two clocks to be synchronized.",
"His breakthrough was that he realized that in every inertial (non-accel... |
[
"WHY do we say that, in quantum mechanics, time does not correspond to an observable? We can obviously measure time, so surely there MUST be some time operator that exists."
] | [
false
] | So I missed a lecture a couple weeks ago and am finally catching up with notes on it. On my lecturer's notes it says "time in quantum theory...is used to label the state, and not an observable". But we CAN measure time, so why does it not have an observable? Surely it has one, and we just haven't found it yet? | [
"in nonrelativistic quantum mechanics, \"time is not an observable\" means that you cannot measure \"the time\" of a particle, as, at what time it is, like you can do with the position. It is not meant that you cannot build a clock, but rather that a particle has a vector of three position operators but no correspo... | [
"exactly, in this formalism, you can't."
] | [
"So basically, a particle doesn't have \"time\" as a property? Like, a particle can have \"the position of the particle\", but you can't say \"the time of the particle\"?"
] |
[
"How do the mechanisms that make time release drugs (such as Adderall) work?"
] | [
false
] | [deleted] | [
"the mechanisms utilized to achieve timed-release effects vary among products. For Concerta (time-released methylphenidate), the tablet is designed to release the medication according to changes in osmotic pressure.",
"http://www.janssen-ortho.com/JOI/pdf_files/concerta_E.pdf",
"See the bottom of pg 24 for spe... | [
"Hm, very interesting. Thank you very much for this."
] | [
"certainly. ",
"drug monographs",
" are available online & must detail the process of release into the body & known mechanisms of action. the above link breaks down the science-ese in which the monographs are written"
] |
[
"Anatomically, what muscles/tendons/etc. move the jaw from side to side or front to back?"
] | [
false
] | Obviously there are those that close the jaw, but I'm curious to know how exactly the jaw is able to move in the other dimensions. | [
"Side to side is accomplished by the ",
"medial pterygoid muscles",
" and the ",
"lateral pterygoid muscles",
"Forward and backwards is accomplished by a couple muscles: ",
"masseter",
"temporalis",
"Of course, I'm probably missing some, I've never really dealt with ",
" anatomy. "
] | [
"You have this mostly correct, upvote for you. Masseter and Temporalis are mainly responsible for superior movement, also lateral movement, and to a smaller degree anterior/posterior (I am not confident that the masseter contributes significantly to anterior movement in humans). I would bet that a few neck muscle... | [
"As an aside to Bruswick.... Masseter and Temporalis are quite involved with lateral movements of the jaw. Contract just your right masseter or temporalis, the jaw most deffinately deviates to the right."
] |
[
"Does the weight increase on a swimming pool structure when the quantity of swimmers increases?"
] | [
false
] | null | [
"Yes (as long as the water doesn’t overflow). People have about the same density as water, so it’s roughly equivalent to adding the total volume of people as water to the pool. "
] | [
"Cheers dude, curious! "
] | [
"This doesn't sound like a limitation of free body diagrams, but rather an illustration of how a free body diagram might be misinterpreted."
] |
[
"Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology"
] | [
false
] | Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical post? No question is too big or small for AAW. In this thread you can ask any science-related question! ... | [
"Is there a difference in how my body processes an espresso diluted with 6 oz of water (Americano) versus chasing an espresso with 6 oz of water? Will my body hydrate/dehydrate at the same rate for both scenarios? Will I feel the effects of the caffeine equally?"
] | [
"General term for what you describe is just a \"ceiling effect\". Not sure if there's a special term for a pre-test post-test type of situation."
] | [
"Yes, they do. It's called participant bias, or subject bias. Essentially, it involves participants of the study second-guessing what's known as \"demand characteristics\" - traits and behaviours that the researchers are looking for in the study. ",
"The participants may (even subconsciously) change their respons... |
[
"Is a klein bottle a three dimensional representation of a mobius strip? What would a dimension higher be?"
] | [
false
] | I was thinking about the shape of a klein bottle and realized its quite similar to a mobius strip. They both have one "side" (side of paper for the mobius strip and inside/outside for klein). So I got to thinking the klein bottle could be a representation in three dimensions of what the mobius strip is in two. So my qu... | [
"Is a klein bottle a three dimensional representation of a mobius strip?",
"No, it isn't -- though it does have mathematical properties in common with the Möbius strip. Both are non-orientable manifolds, for example, meaning (in layman's terms) it's not possible to consistently define a notion of left- or right-... | [
"There's nothing ",
" with a shape that \"passes through itself\", but the Klein bottle is supposed to be a shape that doesn't. At the intersection, it seems like you could move from one part of the surface to the other intersecting part without traversing any appreciable distance. There's nothing wrong with a sh... | [
"Probably better to say that it ",
" a fundamental polygon (as does any connected compact surface)."
] |
[
"Can you eat so many calories that your body can't process them all? If so what is that number of calories?"
] | [
false
] | null | [
"Your question is a bit misleading - you can ingest too much of a substance that your body can't process it, but it's not specifically related to the number of calories that it contains.",
"For instance, sugar more or less all gets absorbed because it can be taken up more or less anywhere throughout the intestine... | [
"From what I've gathered it would still not be very plausible for us to digest cellulose as our digestive system is physically different than those of Ruminants (Mammals that can digest cellulose) for example our digestive system does not have room for allowing the cellulose to ferment. This ",
"wiki",
" page s... | [
"Followup question: Would it be possible to employ the same bacteria (maybe through a fecal transplart) that cows use to digest cellulose?"
] |
[
"Is this plant edible?"
] | [
false
] | on my walk, I think they might be wild beans or peas, can anyone verify? Climate is not far from the coast in San Diego. | [
"Edamame is a food made from soybeans. As a soybean farmer, I assure you that the plant in question is definitely not soybeans."
] | [
"It's hard to see int he pick, but is the plant devoid of foliage/leaves? All I see are pods that ",
"look similar to Okra."
] | [
"No, it has leaves and flowers. I'm about to walk by there, so I'll take some closer pics of the pods, flowers and leaves. It's definitely not Okra, the pods are distinct, similar to a green bean which is my first inclination. I'll get those new pics here in about an hour or so."
] |
[
"Do animals sleep in a segmented pattern or do they sleep only once during a day?"
] | [
false
] | Some human cultures sleep in the afternoon due to the body's natural penchant for sleepiness in the afternoon, while others (myself included) nap if they are particularly tired, resulting in two periods of sleep in one day. Other people sleep in one stretch during the night. What are the sleeping patterns of animals li... | [
"Sleeping patterns of animals vary greatly in terms of length, frequency and predictability, and according to age.",
"A number of mammals sleep for a tremendous number of hours and are only active for a few of them. Koalas are generally only awake about four hours of the day, an issue that's caused by a low-calor... | [
"Thank you for your very informative response!",
"Are humans the only animals, then, that become over-tired and then nap to compensate? It sounds like most other animals that nap are doing so due to their environment. Are humans the only animals who don't sleep when they should and have to make up for it later?"
... | [
"You're welcome, and no to both questions. ",
"Watch a kitten or a puppy some time. They'll fall asleep face first in their food dish after playing too long and too hard or going into kibbles 'n bits shock. ",
"And a predator that hasn't found food in a while can't afford to sleep unless they have no choice due... |
[
"Quick question about thermal expansion?"
] | [
false
] | null | [
"Not really. Thermal expansion is about objects getting larger as they heat up. This is purely a material property: atoms get farther away from one another as the temperature goes up.",
"Bread rising is due to a chemical reaction which causes yeast to release carbon dioxide, pushing the dough outward and forming ... | [
"Bread dough rising on the counter is due to yeast producing gas. Bread rising in the oven is due to thermal expansion of that gas. The heat then solidifies the dough and the bread stops rising. "
] | [
"Most cooking is NaHCO3 (bicarb or sodium bicarbonate) where in thermal DECOMPOSITION where it turns into NaCO3 (sodium carbonate), and H2O (yes water), and CO2 (carbon dioxide) which is what makes baking rise, CO2 makes gas pockets as you said "
] |
[
"Is there actually any evidence that GM-food can cause negative health effects?"
] | [
false
] | Probably not, I guess. | [
"I've only heard of one:",
"http://www.nejm.org/doi/full/10.1056/NEJM199603143341103",
"and it's pretty interesting. They stuck a gene from Brazil nuts into soybeans to increase methionine content. Whelp, people allergic to Brazil nuts then experienced sensitivity to the modified soybeans."
] | [
"The short answer to your question: ",
" People have been genetically modifying plants for crops for a very long time, they just didn't do it in labs over the course of one generation of organisms.",
"The long answer: ",
"*there are political issues involved (free trade, patents, lawsuits, monopolies)",
"*t... | [
"But on the other hand, the other 99.999% of the world got more nutritious soybeans."
] |
[
"Radioactivity question."
] | [
false
] | I red this phrase "The water picks up enormous amounts of radiation, so you add more water and you are generating hundreds of thousands of tons of highly radioactive water." in this . My question is, does water (or other materials) became radioactive when exposed to radiations (and how) or they just pick up radioactive... | [
"While you ",
" make things radioactive by exposing them to radiation by converting stable isotopes into unstable isotopes by absorbing alpha particles & neutrons etc (this is how uranium is \"enriched\"), \"radioactive water\" is as you guessed, just water contaminated with small amounts of other radioactive sub... | [
"Asked recently...\n",
"http://www.reddit.com/r/askscience/comments/hs7e8/when_i_read_about_radioactive_water_am_i_reading/"
] | [
"Oh, thanks."
] |
[
"Does Newton's 3rd law mean that force is conserved?"
] | [
false
] | If so, why is it not taught as a conservation law? If not, why not? Thanks for the answers, but really telling me that force is related to momentum which is conserved, does not answer my question. Is the total force in a closed system always conserved? If not, why not? | [
"that's not a meaningful statement. Think about your bank account. When you withdraw money, you gain money in person and your account loses money. Would you say there's a conservation of \"money transactions\" there? Or rather that there's a conservation of money, and the transaction must respect that. So a force i... | [
"It's actually another way of stating that linear momentum is conserved. Aim Newtonian physics, a force is a change in momentum. So in a force interaction, the change in momentum must be equal for both objects involved. That's another way of saying that momentum is conserved. "
] | [
"I think what's important to note physically, as others begin to mention, is that the only thing that matters ",
" is momentum. A force is just a convenient way to describe the change in momentum over time. But momentum is the truly conserved aspect."
] |
[
"What is causing the buzzing sound from generators and other elecric devices?"
] | [
false
] | [deleted] | [
"Eddy currents in the metal plates that make up the core of the transformer induce mechanical vibration within said plates."
] | [
"Hz is not a measure of loudness."
] | [
"Magnetostriction",
" is the technical term for this."
] |
[
"Why can't we reverse the effects of cooking? and why doesn't an egg turn into a gas instead of a solid when heated?"
] | [
false
] | null | [
"For your first question, when food is cooked the heat energy is absorbed by the molecules to increase their individual kinetic energies. Given sufficient energy input, the increase in kinetic energy can actually break down chemical bonds in order of increasing strength. While it is possible, energetically-speaking... | [
"Thank you. I've been wondering for a while now. I think you cleared most of it up although I'm not sure what folding states of protein means. If you could explain it I would appreciate it :)"
] | [
"You could probably listen to a half dozen biochemistry lectures on the topic, but in a nutshell, there are four tiers of protein structure: Primary structure is the arrangement of the chain of amino acids, the building blocks of proteins. For any given protein, the order of amino acids which comprise it is encoded... |
[
"For someone paralyzed from the waist down, permanently, would their life be easier if their legs were amputated at the thigh?"
] | [
false
] | Sorry, this may seem like a ridiculous question, but if there is zero hope of recovery, totally severed spinal cord or whatnot, wouldn't it help them get around better and enjoy life if they were to dump so much dead weight? Do doctors even consider something that radical? Is there a health reason why this is a bad ide... | [
"Also, what kind of effect would does it have on the heart seeing how it has less tissue to pump to? "
] | [
"how did they operate the rudder pedals?"
] | [
"if you mean they had amputations to better jet fight I need a number of sources on that"
] |
[
"Is there a consensus among scientists on the concept of infinity?"
] | [
false
] | My real question is based on the principles of the expanding universe, and sub-atomic particles. If what I understand is correct (and it probably isn't, so be gentle) sub-atomic particles are things that are smaller than atoms, such as quarks and hadrons. From what I understand, atoms weren't really discovered until th... | [
"No, that's absolutely not it at all. When you're doing an experiment, the scientist's eyeglasses prescription does not contribute to the margin of error. We quantify things objectively, thus removing the \"oh but every individual is different\" wankery."
] | [
"So we will break this down. ",
"There are Leptons, Quarks, and Bosons. As far as the standard model is concerned they have no internal structure. Could they have internal structure? Yes, certainly. There are other theories, such as string theory that says that at the smallest scales these no longer points but 1 ... | [
"Figured someone would bitch about that, but strictly speak there will always be more than what we can find due to not only the fact that infinite is not finite, but because we will reach a point where we physical can't find them due to the expansion of the universe."
] |
[
"If our atmospheric pressure were lower would we perceive the ambient temperature as warmer or colder?"
] | [
false
] | Given the same climate and nothing changes except for lowering the pressure would it feel warmer or colder to us? I understand that water boils more easily at lower temperatures. So if we are made mostly of water it should seem warmer to us right? | [
"I realise that I don't know the full answer to this, but perception of temperature is about the rate of heat loss from the skin against what your thermovascular system is trying to achieve (see Fanger's comfort equation). This is a mixture of radiative, convective and evaporative heat loss.\nEvaporative loss is th... | [
"But he stated the climate was the same, presumably then the dry bulb air temperature is the same. Of course with less air in general, global warming would be reversed, and the climate would cool down through increase radiation to space, but this is not what the OP asked. Perhaps they are thinking of for example, a... | [
"Ow, so the temperature stays the same only the pressure would be lower, like that? Then I misunderstood the question, sorry. "
] |
[
"Which recreational drugs lead to cognitive decline in healthy, young adults?"
] | [
false
] | I expect frequency of use/abuse, dosage, duration of use, and levels of stress/anxiety/depression to act as key variables. Which drugs are least forgiving? Can faculties be fully regained? Are emotional/genetic factors way more important? I am basically looking for more insight into whether 'drugs make you slower/stupi... | [
"Almost all of them in high enough quantities. I recently read an article about how marijuana stunts the development of your brain (which finishes around age 25). If you were to pick up the habit before your brain is fully devoloped you run a higher risk of various mental ailments: schizophrenia, depression, as wel... | [
"I can find the sources if someone wants",
"I think everyone on this subreddit wants to have sources whenever it's possible."
] | [
"I can find the sources if someone wants, but after attending enough lectures from people studying addiction, I can reasonably confidently say that Cocaine is one really bad dude, they all believe it irrevocably screws up your brain (they have this extremely cool/sad new cocaine self-administration model in rats: t... |
[
"Is it possible for me to develop a cold from a virus i was exposed to before qnd fought off and/or been gone latent in my body without being exposed to other sick people? How long can cold viruses be latent in the body with the ability to reactivate?"
] | [
false
] | null | [
"Not sure about developing a cold but if you look at CMV (cytomegalovirus) and EBV (Epstein Barr virus), those are both prevalent in most people as latent infections. If you get another infection, are immune suppressed, or pregnant, then those viruses can flare up and cause their relevant symptoms. ",
"Probably t... | [
"There are a number of viruses that are never flushed out of the body and they remain in the body after infection. In certain conditions they can manifest years after the initial disease has passed. But that is very rare. \nFlu viruses, RSV are not able to linger in the body.",
"If symptoms re-emerge days (5-6 da... | [
"There are over 200 viruses known to cause a \"cold.\" They include several families, like rhinoviruses, adenoviruses and coronaviruses. As a rule, those families don't \"lie dormant\" like herpesviruses.",
"Getting a cold often incurs some immunity to that virus, and maybe a few of its cousins, for a few months ... |
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