title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"What is the Greatest Degree of Convexity that Still Appears Flat to the Naked Eye?"
] | [
false
] | ...assuming a highly polished surface, on a hand sized object, viewed at ordinary angles and lighting conditions? Edit: also assuming a glossy, and non textured surface. E.g.: small pane of opaque glass | [
"Is it textured or uniform? Glossy or matte?"
] | [
"Ok, this is going to be a long answer. First, I should point out that the form of the answer might not be exactly what you are looking for because it's impossible to give a single number: the answer is going to depend on a lot of factors like (a) lighting conditions, (b) material properties, (c) distance to the ob... | [
"Uniform and glossy."
] |
[
"Why do we like the taste of some foods but not others?"
] | [
false
] | null | [
"Your sense of taste is a powerful survival tool. Sweet things and fatty things (generally) provoke pleasant reactions because they are full of sugar and fat, which is otherwise a fairly rare resource in nature!",
"Unpleasant tastes can be both innate and learned. Bitter flavors tend to be automatically offputtin... | [
"Some of it is hereditary. One extreme example is the chemical ",
"Phenylthiourea",
". So I'm sure other flavor chemicals may have similar variations. Evolution would favor us liking those that have the most energy. Like sugars and fats."
] | [
"But what about people who have different tastes? E.G. People love olives or sardines vs. people hate them. Is this just natural variation within the evolutionary influence of sweet/fatty etc. etc. or is it more closely linked to something else?"
] |
[
"Sight and Color Questions"
] | [
false
] | [deleted] | [
"here",
"Edit: After rereading #2... All three types of cones would activate based on light at say 400nm. However, each would activate to a different extent. Our percept is the result of the proportion of activation for all three cones. So an animal that had the same small cone as us but different other cones wou... | [
"thanks for the reply",
"As for 1a, could you explain how much difference variation could be? Is it possible for one person's cyan to be another person's pink, or is the variation less significant and more like cyan-turquoise?",
"And I'm nearly positive the answer is no, but is there anyway to use these peak wa... | [
"Since everyone's brain and eyes are different, no one gets the same signal or encoding from a particular light wavelength. There is NO absolute representation of color (or any percept, for that matter). It's different in everyone. However, it is possible to agree on a labeling (see 2). ",
"We could take two colo... |
[
"Is how rested you feel proportional to the amount of sleep cycles that you have had that night?"
] | [
false
] | null | [
"Disclaimer: I am not a professional. I am, however, a connoisseur of sleep (as well as not feeling rested); I have narcolepsy with cataplexy. A full night of sleep is generally marked by ",
"a sequence of sleep cycles that vary in length and \"depth\"",
" (i.e. which stages of non-REM or \"NREM\" sleep one r... | [
"Rested in the sense of mental fatigue, general alertness, muscle fatigue?"
] | [
"sigh"
] |
[
"Can individuals with complete hearing loss \"hear\" via bone conduction? E.G. Shower water hitting your body, resonating bass at concerts etc.?"
] | [
false
] | Theoretically I'd assume this makes sense, but are there conditions which inhibit this? | [
"Complete hearing loss does not come from the outer or middle ear - the ear canal, drum, or tiny bones. If you have a problem with these, surgeons can and do repairs and restore some, or sometimes even normal hearing.",
"Complete loss comes from damage to the inner ear, to the structures that convert vibrations t... | [
"No. If the nerve is damaged (sensorineural hearing loss), they would not be able to hear at all from that side. This is opposed to conductive hearing loss (e.g. ear wax, ear bone disruption, ear drum injury) which you can rehabilitate with bone conduction devices.",
"Sometimes, if an individual has complete hear... | [
"So, yes, or no?"
] |
[
"Is there an isothermal DNA application method that can amplify sheared DNA that only has 70-100 base pairs?"
] | [
false
] | [deleted] | [
"Have you tried ",
"/r/labrats",
" or ",
"/r/biology",
"? This is a totally valid question for AskScience, I just want to make sure you get an answer and those two subreddits are great."
] | [
"Have you looked into RPA (recombinase polymerase amplification). My lab has been having good luck with it recently. 100bp might be pushing it, since the technique requires longer than normal primers (~35bp on each end), but it runs very quickly and at 37C. The website for the company that makes it is ",
"here... | [
"I kind of figured that RPA targets would be too long for you, but it was worth a shot, since it's so easy to work with compared to the others."
] |
[
"Does increasing the volume on your iPod drain the battery any faster than having it on low volume? Will one type of speaker or headphone drain the battery any faster/slower than another?"
] | [
false
] | null | [
"This is incorrect. In typical iPod usage, the backlight turns off after a few minutes. Headphone volume can make a 10-20% difference in the power consumption (and thus, battery life).",
"Source: Me - I did power-consumption and battery life testing on the first few generations of the iPod."
] | [
"The power consumption depends on your headphones' ",
"impedance",
"; the lower the impedance, the more current is drawn per volt of input signal, and the louder your music sounds (at a given volume setting).",
"Earbud-style headphones typically have an impedance of 16-32 ohms, and the output from an iPod's h... | [
"The amplifier on you iPod has a relatively low power consumption - much less than the back-light for the screen or the wi-fi. Therefore there won't be a noticeable difference between low or high volume"
] |
[
"Waking up naturally VS waking up via interruption (i.e. alarm clock). Are there any negative/positive long term side effects?"
] | [
false
] | Waking up naturally: I normally feel more refreshed when this happens - even if its a 6 or 7 or 9 hour sleep. Waking up via interruptions: Sometimes I feel more tired than before I went to bed. Anything bad/good about this? | [
"Your body has 4 phases of sleep elaborated here:\n",
"http://www.jetlog.com/uploads/pics/img_main_SleepStages_01_US.jpg",
". ",
"You want to wake up at the peaks of your cycle (Stage 1), also known as REM sleep, this is when your sleep is the lightest and when you dream. Naturally waking up ensures that you ... | [
"Stage 1 is not REM sleep. "
] | [
"gj you ruined the placebo effect for him :/"
] |
[
"Dear /r/AskScience how come H20 has to be bonded for us to receive the benefits of hydration?"
] | [
false
] | null | [
"Because Oxygen has an electron config that leads it to bond, -2, it naturally links up with other Oxygen to form O2. In order to get O to show up on its own, you need to release it from its natural O2 state, which requires an input of energy. Some chemical reactions in the will produce oxygen radicals, or O-, but ... | [
"H2O and separate H2 an O2 behave very differently. ",
"H2O is a solvent that rapidly dissolves various molecules and makes them available for chemical reactions. H2O is also a low energy and thus stable molecule, so it can take part in various chemical reactions without coming apart. ",
"H2 is a very light gas... | [
"Awesome answer! I just have one question though, what is the difference between O2 and O?"
] |
[
"Is the Earth's magnetic poles destined to switch?"
] | [
false
] | My physics teacher told my class that the Earth's magnetic poles are due to switch in the not so distant future, so north becomes south and south becomes north. Is this true? | [
"Yes. It happened many times in the past and it will happen again. But \"not so distance future\" is in geological terms. The time between reversals changes from 100,000 years to1,000,000 years and it takes hundreds of years for it to be completed once it started. Last reversal happened 750,000 years ago. "
] | [
"what will the effects be? Will human technology be affected in any serious way, asides from compasses now pointing southwards?"
] | [
"The magnetic field that we feel from the earth is very small so a variation in it won't do anything to us directly. As you might now, the origin is from the core and the field force drops at 1/r"
] |
[
"Do trees grow rings at the equator?"
] | [
false
] | And if so, do they correspond to one year of age like tree rings in other places? It seems like since there aren't traditional seasons at the equator, the trees either (a) wouldn't grow in a way that would form rings or (b) the rings would form at some other frequency. | [
"Equatorial hardwoods still have a growth cycle. ",
"While the sun may wobble north and south through the year, other factors, such as monsoon patterns, impose their own impact. ",
"Growth during wet season will leave different rings than growth during dry season, even if the sun is directly overhead during bot... | [
"Many tropical trees do have rings, and many others don't (",
"example",
"). Tree rings are indicative of differentiated growth cycle (warm/cold or wet/dry) so many species that adapted to dry/wet cycle form rings. However many tropical trees with rings don't follow annual rings (false-rings) which makes it dif... | [
"I don't think that this is because of the latitude at which they grow. I grew up in Phoenix, AZ which is 34 degrees north, and we had palm trees, cacti, and yucca. We also had plenty of other trees that grew in rings."
] |
[
"If I eat a \"normal\" meal, then exercise, my body is flushed with insulin but my blood sugar remains normal. If my Type-1 diabetic girlfriend doses a normal amount of insulin for a meal, then exercises after the meal, she quickly becomes hypoglycemic. What's up?"
] | [
false
] | [deleted] | [
"I've got what I believe is the correct answer to you, which also describes why exercise (with appropriate insulin dosing) is supposed to have a positive effect on blood sugar in diabetics.",
"You sound like you know a bit about this, so I'll get right into it: What really allows sugar to enter cells (and leave ... | [
"I did not know about GLUT-4 and will have to read up on that, but sorry to nit pick: My original point was that I don't understand why the insulin produced by my pancreas along with a big dose of exercise for me after a meal does not crash my blood sugar.",
"If glucagon production is affected in Type-1 diabetics... | [
"Ahh, I see what you mean. Yeah, I suspect it's a case of glucagon being affected as well."
] |
[
"If heat is random motion of particles, and the faster you go, the more time dilatation you experience; do hotter things experience more time dilatation?"
] | [
false
] | How much slower is time as experienced by a human compared to something at absolute zero? | [
"yes (there's an effect) but no (it's negligible). we are talking ridiculous temperatures here, on the order of mc² = kT. at the point where temperature would contribute significantly to the total energy of the particle. at these temperatures a whole lot of other degrees of freedom then just particle motion are... | [
"I'm not sure how hot stars get, but after looking up the hottest stars I can do some estimation and find that even then, the highest speeds are less than 1% the speed of light, and any time dilation effects from motion are still going to be small. There are definitely some stellar processes that have much higher s... | [
"What about the particles of a star? Do their heat add enough time dilatation to need to be accounted for when calculating stuff about stars?"
] |
[
"Are there any theoretical Non-Carbon Based Organisms?"
] | [
false
] | In the scientific literature are there any non-Carbon based organisms that are complex in nature? | [
"Are there any theoretical Non-Carbon Based Organisms? ",
"In the scientific literature are there any non-Carbon based organisms that are complex in nature?",
"This seems to be two different questions.",
"Are there ",
" non-carbon-based organisms? Sure, you can draw chemical structures all day and imagine ... | [
"Are there theoretical non-carbon-based organisms? Sure, you can draw chemical structures all day and imagine life forms based on, for example, siloxane chains.",
"You can go further and propose string-based lifeforms in the hearts of stars, that paper got a lot of talk last year. \"Can Self-Replicating Species F... | [
"In my second question I forgot to include theoretical... essentially was wondering if in scientific literature there are any theoretical models of non-carbon based organisms that are complex."
] |
[
"What were human sleeping patterns before working hours?"
] | [
false
] | null | [
"It is thought that people used to have segmented sleep. Some detail here:",
"http://www.bbc.com/news/magazine-16964783",
"The disappearance of cultural references to this type of sleeping pattern coincided with what the OP expected... somewhat. I've most often read people blame the shift on artificial light.... | [
"None of the other great apes are nocturnal; we probably weren't either. Our eyes are not really adapted for night work.",
"Otherwise it becomes a question of energy conservation and what time of day is the best for hunting/fishing/foraging. That depends on the location.",
"It has been reported that some fami... | [
"This is a bit off. The human circadian rhythm is, on average, slightly longer than 24 hours and is entrained (re-synced) to the local environment by sunlight exposure. The suprachiasmatic nucleus is above the optic chiasm and so is well positioned to detect light exposure. It then triggers the pineal gland to rele... |
[
"What would be a \"realistic\" reason for aliens to invade? Are there any natural substances common on earth that are rare on a galactic scale?"
] | [
false
] | null | [
"As others have said, raw resources like water, hydrogen, metals, and silicon are readily found throughout the universe so it's unlikely that they would come for those especially since interstellar travel would already take tremendous amounts of resources. They'd likely have self sufficient food, water, air an... | [
"If they can live in Earth's ecosystem, then we have a whole planet sitting here ready to move in. (Even if they easily ",
" build space habitats or terraform hostile planets or whatever, why not take this one?)",
"Some people have postulated that biological materials (plants and animals) may be very valua... | [
"One of the most interesting ideas I’ve read about (posited by the author Iain M Banks) is one of alien tourism. The idea is that it is super rare to have a moon that’s the same size as the sun when you’re standing on the surface of a planet, and that the total solar eclipses we get would draw intelligent, curious... |
[
"If I blow into a straw that's in hot tea, does the tea cool down?"
] | [
false
] | [deleted] | [
"If the tea is warmer, yes. If the tea is cooler, most probably not.",
"Most probably because there could be evaporative cooling which I find unlikely given the high humidity of breaths."
] | [
"If the breath temperature is lower than the tea temperature, yes, you will have heat transfer from the tea to the gas (breath), cooling the tea slightly. "
] | [
"Yes, but I think it would be less effective than blowing on top. When you blow on the top of the liquid, you're removing a small layer of evaporated liquid. Evaporation carries away a bit of heat from the liquid, and you're blowing that away, leaving the remaining liquid to be cooler.",
"Or in simpler terms: the... |
[
"If Earth's magnetic poles migrate, will the aurora migrate with them?"
] | [
false
] | If, for example, the magnetic north pole shifts so it's under Michigan, would the Midwest have aurora the way the Arctic does now? | [
"Yes - the charged particles from the Sun follow the Earth's magnetic field lines, which will converge wherever the pole is.",
"(I wonder if there's actually been any work on the position of the aurorae drifting with the pole's slow movement... To Google!)"
] | [
"Yes! I learned about this in geology class last semester. In fact there will be up to 8 magnetic poles in the middle of the polar shift and auroras will cover the Earth. Cancer rates will increase too, as the Earth's magnetic field dies down while it's happening. "
] | [
"Cancer rates will increase too, as the Earth's magnetic field dies down while it's happening. ",
"This has not been proven. It's actually very much debatable. The atmosphere may be able to block the additional radiation well enough that the difference wouldn't be significant.",
"From ",
"Wikipedia:",
"S... |
[
"If every coulomb of charge that flows from a 1.5V battery transfer 1.5J of energy, how can a 2V battery transfer 2J per coulomb of charge if it’s the same amount of electrons in every coulomb?"
] | [
false
] | null | [
"Each electron has more energy."
] | [
"Follow-up question!",
"How is the energy in the electron stored/portrayed? Is it moving faster? Prone to shake? Shake more? Can we see and define a difference between two electrons with different amount of energies?",
"Or is this just asking “what is energy?”..."
] | [
"It's potential energy. If you imagine the electrons moving through the circuit as a ball rolling down a hill, at the negative terminal of the battery, the electrons are at the top of the hill. As they move around toward the positive terminal, they are rolling down the hill.",
"When you increase the voltage of th... |
[
"If we can perform addition on two sound to get the sum of both, can we do the opposite?"
] | [
false
] | So, we know we can have background_music.mp3 and voice mixed into a song.mp3 - Then, can we subtract the background_music.mp3 from a song.mp3 to produce voice.mp3? | [
"Short answer is yes. It's much harder to do in practice, though, especially if you don't have the exact spectra/waveforms of the signals you're trying to \"subtract.\""
] | [
"much like noise canceling works, right?"
] | [
"I imagined to perform C - B = A you need C and B, but you are suggesting it can be done. What gives?"
] |
[
"Why are some chemical reactions irreversible?"
] | [
false
] | null | [
"Technically, there are none. It's just a matter of how complicated and energy-intensive it is to revert them.",
"For example, if you burn wood and capture all the gases and ash, you could use an organic machine that uses solar energy to turn CO2, water and minerals into cellulose structures (aka trees).",
"You... | [
"The short, practical answer here is that irreversible reactions generate products that are significantly lower in energy than their starting materials. As with a lot of chemistry, the in-depth answer is a bit more complicated and not a black and white situation. ",
"A reaction is called spontaneous if it is favo... | [
"To add a little context to what's being said in this comment: you can think of chemical reactions as molecules trying to reach equilibrium. So for many reactions, to make it go in the reverse direction, you can just increase the amount of product vs reagents. But remember things like heat, light, molecular structu... |
[
"If somebody gets a new organ and you check ~50 years later, will the organ still have the DNA of the donor?"
] | [
false
] | null | [
"It depends on the organ, and on what cells you look at. Some cells (monocytes, for exemple) are able to migrate inside tissues, and they would have the DNA of the host.",
"However, the huge majority of the cells would have the donor's DNA, yes."
] | [
"That is the standard protocol, yes. However the man who designed the protocol now believes that it is possible to reduce the dosage to zero after several years. I'm not sure if a protocol has been designed around this, though. Anecdotally, I have met someone who did stop taking the drugs.",
"However I don't thin... | [
"It all is about cell replacement. In a stable organ as cells wear out they'll get replaced by adult stem cells. When you transplant an organ you also bring with it the resident stem cell population, but stem cells are a bit uppity. It's a bit of an unsolved question, but it's possible that as the transplanted orga... |
[
"How is light created on the atomic level?"
] | [
false
] | Take for example, a lightbulb, it is completely dark until turned on. How do atoms work with light? Sorry if this is hard to understand, I am having a hard time putting my thoughts into words at the moment. | [
"The light that we see is the result of a change in energy levels of electrons in an atom. Electrons have very specific energy levels that they are able to occupy, but always try to return to their lowest level possible. In order to change energy levels, they need to absorb or release the exact amount of energy tha... | [
"Wouldn't light in a filament be more a result of black body radiation caused by the resistance of it?"
] | [
"Yes the atoms vibrate due to the high temp. The electrons accelerate and decelerate. This causes energy to be emitted as photons. Some electron accelerate or decelerate faster or slower than others giving a spectrum of wavelengths. You can divide the blackbody spectrum by their repective photon energys and get how... |
[
"Do the effects of PEDs affect the children of the athletes that take them?"
] | [
false
] | For example, take Lance Armstrong. If he had children while on EPO, testosterone and other PEDs would they reap the benefits as well and be "super children" for lack of a better term? | [
"Let's think about it this way. The only material passed from father to offspring is what is included in his sperm. Therefore, unless he does something to alter his sperm, nothing will be passed on. So for Lance, beyond having ultra awesome genes (let's face it, the guy was still a great athlete without PEDs, altho... | [
"So would it be possible if someone like Marion Jones had a child while on PEDs the child would reap the benefits?",
"Also, since the use of testosterone and EPO allowed Lance to train and compete at inhumane levels would that sort of boost be passed on?"
] | [
"Basically, what I am saying is that mother and offspring exchange blood, nutrients, etc, while the only thing the father provides is the DNA from his sperm. Effects of drugs, be it crack or HGH will be passed onto the child through the mother. I am in no position to comment on long term affects, but I can pretty m... |
[
"Where does the matter \"swallowed\" by black holes go?"
] | [
false
] | I've been told many different things, for example that the universe is like a table cloth and black holes are like dips in the cloth and that matter collects in the bottom making the dip larger. But what exactly is a black hole and what happens when matter falls into it? | [
"Worth pointing out that a black hole need not be a singularity. Any object dense enough can be a black hole. I read somewhere that singularities might be impossible with a theoretical maximum density for any matter. Only seen it mentioned once though, the current school of thought is that most black holes are s... | [
"We can't tell where matter entering a black hole goes because they have an event horizon. Once anything, even light, crosses this point, it's unable to escape the pull and is drawn into the black hole. This means that anything 'beyond' the event horizon is un-observable to us on the outside.",
"http://en.wikiped... | [
"Matter is something like polysterene. Throw a huge brick in a bucket of paint thinner and watch it just WHOOOSH disappear. Matter is mostly hollow space and black holes are what's the matter do without all the hollow space inside the atoms. SQUISHHHH"
] |
[
"Where did all of the organic mass come from?"
] | [
false
] | The surface of the earth is teaming with life. Life is everywhere. And, we're living on a surface that is layers and layers, up to a mile, of previous living things. Oil is supposedly previously live creatures and is far below the surface. Limestone is huge amounts of formerly live organisms compacted over time by the layers above and the sea above. Where does all of this mass come from that we can pile hundreds of feet to a mile of organic matter across the surface of the earth. All of these components came from the primordial stew? | [
"There wasn't a carbon cycle before there was life. ",
"Yes there was, that's sort of the point I am making (although perhaps clumsily). Prior to the appearance of life (and keep in mind that our current understanding is that life appeared ",
" early, ",
"at least 3.8 billion years ago, and possibly earlier",... | [
"It helps to answer this kind of question to take a step back and view the ",
"carbon cycle (CC) as a whole",
". ",
"The CC essentially describes how carbon transits from one reservoir to the next. As you rightly point out, some of these reservoirs are organic, others are not.",
"One massive reservoir is th... | [
"I really love this response. Thanks. ",
"I guess what I'm still wrestling with is that there's enough new biomass created over time that the biosphere is now becoming part of the lithosphere. It's getting layered in. It seems that the biosphere is getting something for nothing - but, you've convinced me tha... |
[
"In general, what type of information is obtained through spectroscopy?"
] | [
false
] | null | [
"You should check out the ",
"Wikipedia page",
" first. Spectroscopy is a ",
" broad term that encompasses many techniques, each of which can provide different information on the system being examined."
] | [
"A ...spectrum. Essentially a range of electromagnetic energies that have been absorbed by the sample. Or in the case of mass spectroscopy, a breakdown of the atomic weights of the constituent atoms. In either case, the objective is to identify the material."
] | [
"All those emissions or absorption lines tell you what the spacing between energy levels is. Every atom and molecule has a unique energy spacing structure which is like a fingerprint. If you see the same pattern, you can conclusively say that sample contains that atom or molecule, even if the structure is billion... |
[
"How do Google Maps and other GPS systems calculate distance between two points?"
] | [
false
] | Is it the birds eye distance or the actual distance a car would travel. For example: Looking at a right triangle, the length (birds eye) would be much different than the hypotenuse (actual distance). This would be significantly different when looking at distances between the bottom and peak of a mountain. | [
"Most GPS systems use graph-search algorithms for path-finding such as ",
"Djikstra's Algorithm",
" (in reality, the algorithms used by Google Maps, Bing Maps, etc. are considerably more complex and are likely trade secrets, but most of them, in concept, are very similar to Djikstra), where the route is a colle... | [
"Also, since Djikstra's algorithm runs slow when you have hundreds of thousands of data points, most of the paths are probably precompiled to simplify the process."
] | [
"It depends on where you are and your GPS unit.",
"If you are in the wilderness, most nice GPS systems are pretty good about calculating elevation as well as x,y coordinates. For most distances you care about when using a GPS, it is trivial then to calculate a hypotenuse. In order to have elevation date, you need... |
[
"When you are sick they tell you to cough up as much \"infected\" phlem as you can and get it out of your body, is coughing up and then swallowing it as effective?"
] | [
false
] | There are many situations where it is not feasible or socially acceptable to get rid of the phlem you just coughed up so people just swallow it, is getting it out of your lungs and into your stomach as effective as out of your body? does it just get stuck in your throat again when you try to swallow? Also, I realize phlem might not be the right word but you all know what I mean. | [
"Normal lung secretions are designed to end up in the stomach.",
"\nThey are tracked up through the bronchioles and bronchus by cilia (small rhythmically-flailing processes). They reach the oesophagus and are then swallowed. Any pathogens trapped in these mucous secretions are then destroyed in the highly acidic ... | [
"It is a dire fate indeed for an erstwhile fiercely pathogenic upper respiratory targeted microbe to end up surrounded by pepsin and hydrochloric acid, with nary an alveolus in sight :-O"
] | [
"Though stomach acid will most likely kill bacterial/viral infection, high amounts of mucus in the intestinal tract will often cause diarrhea. "
] |
[
"Why is it so much easier to fall asleep in class than it is in my bed when I actually need to sleep?"
] | [
false
] | null | [
"This is a response directly to this statement and not the question as a whole, but I imagine that it's because, in class, you are trying to focus on a subject that you may find boring or uninteresting. When at home, your mind is free to wander and imagine whatever it is that you feel like. Internal stimuli can be ... | [
"Genetics major. =)",
" By the way, I think this statement alone has made my entire week. Thank you."
] | [
"I feel like that's the same reason you instantly wake up after the class you couldn't even keep your eyes open in. You've got stuff to do again, your brain is ready to think about a multitude of things. "
] |
[
"Have we come any closer to understanding the mind/body problem?"
] | [
false
] | null | [
"You should clarify which part of the mind-body problem you are referring to. Working theory is that the mind is a phenomenon that arises from processes in the brain. There are numerous brain damage cases that illustrate this effect. When the brain is damaged, the mind is altered.",
"It is a mistake to think of... | [
"It is safe to say that all creatures that possess a brain have a mind of some sort. The supporting evidence is that we have brains and minds that are tied together, and there is no contradictory evidence.",
"On the topic of consciousness, however, there is mounting evidence that neocortical areas near the system... | [
"This is the correct answer. For anyone looking for more reading, the name of the problem is called the \"Hard Problem of Consciousness\"."
] |
[
"Schrödinger's cat... it seems like a ridiculous concept, can someone elaborate?"
] | [
false
] | [deleted] | [
"Other people have pointed out the implications of the thought experiment***, but it is worth pointing out the very reason why Schrodinger made the argument originally (although it comes from discussions with Einstein) which was to highlight some of the points you're making; the absurdity of extrapolating the quant... | [
"Why is it assumed to be this way as oppose to just something definitive happening?",
"This is what Einstein would have said, as he refused to believe that nature was not deterministic. It turns out though, it's actually possible to prove mathematically that certain physical situations are impossible to explain ... | [
"I find that Wikipedia does a very good job",
".",
"Basically the idea is that if the quantum state is an observer independent fundamental object, then I should be able to write down the wavefunction of a cat, basically extrapolating the wave upwards from microscopic to a macroscopic. You need some quantum proc... |
[
"is there any animal who commits suicide?"
] | [
false
] | null | [
"Here",
" you will see how some penguins commit suicide by separating from the colony to wander aimlessly in the wilderness. It is not direct suicide, but suicide none-the-less."
] | [
"There was that thing about the bear in China that killed its cubs then herself. Let me see if I can find it. ",
"Here's more info."
] | [
"if you poison yourself before you are taken by other predators, mayby you won't be targeted by other predators?"
] |
[
"I want to learn more about statistics and probabilities. Where's a good place to start?"
] | [
false
] | null | [
"There are some good books that put stats and probability into real world everyday context. Just check out the non-fiction section of your local library. My favourite was \"Conned Again, Watson!: Cautionary Tales of Logic, Math, and Probability\""
] | [
"I usually find it easier to use a book rather than wikipedia for learning, I used \"Mathematical Statistics and Data Analysis\" by J A Rice when I studied statistics. Using literature and doing the problems is usually a good start but as with everything you only get good when you practice your knowledge. Do you ne... | [
"if you have a 2% chance, then after 50 attempts you must be successful",
"With that sort of probems, i find it easier to calculate the opposite outcome: what are the odds to fail all 50 attempts ? It's 98% to the power of 50 = about 36%. If you have a 2% chance, then after 50 attempts your odds of success are on... |
[
"What does it take to domesticate an animal?"
] | [
false
] | I've been wondering about this question for some time now. Just thinking if certain types of animals should be easier to domesticate than others, and what would it take? for example, I know there were experiments to domesticate foxes, but there were difficulties. But what about a sloth? don't know if I'm allowed to ask another related question but I also wondered what would happen if dogs were bred selecting the smarter ones, creating a new race based on intellect, how 'smart' of a dog could we get? | [
"Domestication is very breed dependent",
". Take dogs and cats, for example. Dogs have an enormous range of size compared to cats, and many morphological changes in dog breeds have been recorded just in the ",
"last 100 years",
". Cats do have a range of features as well, but not nearly as broad a range as wh... | [
"The animals that would probably lend themselves best to this would be animals with a short breeding cycle, and animals that have been shown to have adaptable behaviours. ",
"Note that some animals are thought to have domesticated themselves. ",
"wiki link, sorry",
".",
"Do also remember that intellect is a... | [
"It seems like your 1st question has been answered in depth already, but about the smart dogs; you could breed dogs to be the smartest creatures on the planet. The only limitations are time and physical impossibility.",
"How do you think humans got this smart? We didn't begin that way. If you could measure int... |
[
"What happens to my taste buds when I put a spoonful of hot food (hot soup, hot pizza, hot lava) into my mouth?"
] | [
false
] | null | [
"There are large concentrations of thermoreceptors in your tongue that detect the heat. That's how you can tell that food is hot.",
"As for your taste buds... well, under high temperature, their rate of degeneration accelerates. A good amount of lava would burn away your tongue, for instance."
] | [
"A hot spoon of soup, or a sip of hot coffee will cause downstream signalling of your thermosensors, so you detect the heat, if it is too hot the downstream signalling will cause the sensitisation of itself and other receptors by phosphorylation. causing your tongue to be tingly and weird (your sensors are over fir... | [
"What's the feeling we get after burning our tongue? The crispy weird taste buds?"
] |
[
"Why do some people faint/vomit at the site of blood/severe injury and others not?"
] | [
false
] | I can watch operations on TV, I've seen people get deep, bloody cuts on faces, arms, legs and this doesn't bother me - but when I get a deep cut on my own body, I shut down. I sweat, feel nauseous and I generally start to feel faint and light-headed. What's going on here? | [
"This is semi-layman speculation, so please don't downvote me to hell for trying!",
"This is due to the ",
"vasovagal response",
". Essentially, when presented with a trigger such as a cut or injury or even seeing someone else get injured, a cascade of responses fire off.",
"On one end of the spectrum is t... | [
"Correct! ",
"I would like to add that Vasovagal syncope can occur at any age, but is more common in those under 40. Also, in addition to nausea, vomiting can occur. "
] | [
"Thanks!"
] |
[
"Which form of fusion power confinement is closest to producing net energy? Tokamaks, Inertial-Confinement, or something else entirely?"
] | [
false
] | I know that the two biggest players in fusion power are currently Inertial-Confinement Fusion and Tokamak Magnetic-Confinement Fusion. I'm curious, which of those is closer to producing viable commercial fusion power? I've heard that our best fusion efficiency so far has been JET, which has achieved a Q value of 0.7. As I understand it, that represents the total energy output divided by the total energy input. I know that that discounts the efficiency of the generator, so you need a Q >10 or so to have a net energy gain. I've also heard the somewhat-recent story about NIF reaching fusion breakeven, but I'm not sure what they mean by that, as the articles I've read on it were all non-scientific and did not actually explain what that means. Wikipedia tells me the actual gain from that experiment after accounting for the inefficiencies of the lasers (which I is Q) was actually only about 0.0077. From what I see, it appears that tokamaks are orders of magnitude more efficient than inertial-confinement fusion at the moment. Am I correct in that statement, or am I missing something? And is there any other reason that inertial-confinement is considered superior to magnetic-confinement for power generation, if not the pure efficiency? | [
"NIF recently was able to get enough fusion energy out of the capsule as it put in with the lasers. Of course this is not break even since the lasers are very inefficient. I think they are only 1% efficient and then you have the other inefficiencies along the way that generate that power. They are about an orde... | [
"Yeah, I was somewhat curious as to how ICF would produce continuous levels of power given the way they use fuel pellets.",
"What sort of efficiency do we get out of the plasma heating methods that tokamaks use?"
] | [
"I am not as up to date on Tokamak efficiency. I only know about NIF stuff since I know people working on it. "
] |
[
"How is it possible that myopia (nearsightedness) has so far survived in the gene pool?"
] | [
false
] | How is it possible that myopia has not been eliminated from the gene pool? As far as I understand, it would give a major disadvantage to someone living in the wild: less able to find food, navigate around and avoid being eaten by tigers. I have myopia and I can't possibly imagine myself surviving in the woods or in a jungle without glasses. How could ancient people (100,000+ years) manage to survive with myopia? This has bugged me for quite some time.. Thanks! | [
"Ahhh... myopia isn't very well understood. There is believed to be a genetic and environmental cause involved in it's development",
"http://disease-reference.com/Myopia.htm",
"Makes reference to studies done on tribal native americans before introducing them to school and stuff like that. ",
"Studies done wi... | [
"There are a lot of possibilities when conditions that seem to be detrimental stick around. One, as lwbannister posted, is that there's a large environmental component--that is, something about the modern world (possibly reading lots of small print close up) increases the incidence or exacerbates the severity. An... | [
"This is probably the correct answer. When I first noticed I was having trouble seeing the board in high school while sitting in the back, biologically, I had been sexually mature for about five years. So I would have had more than enough time to reproduce before getting eaten by a lion, tiger or bear."
] |
[
"How can Methyl Propanoate be formed with ethanol as the only organic reactant?"
] | [
false
] | I can't think of any process that I've been taught that could result in it, Is there a way in which a methyl group can be taken from one molecule of ethanol and added on to another to form molecules of propanol and methanol? | [
"I wasn't aware that it could. What's the context?"
] | [
"For ethanol to methanol you could: elimination reaction (forcing conditions), ozoneolysis, sodium borohydride. all of which can be completely inorganic."
] | [
"It's this question I was emailed from RSC.org.",
"Though I've worked it out now, it included reactions with hydrogen cyanide and hydronium to from propanoic acid and fission of dehydrated, hydrolysed ethanol which was then reacted with hydroxide ions to form methanol.",
"I can go into more detail if you're int... |
[
"What is the closest thing to a frictionless surface?"
] | [
false
] | null | [
"I don't know about frictionless surfaces, but superliquid/fluid substances come close. They are liquids which can ignore friction from surfaces when at extremely low temperatures (2K) or under extreme pressure. ",
"Here's a video of superliquid helium"
] | [
"In particular, supppose I have a tube filled with superfluid liquid helium, and I find a way to give the helium an initial spin. Will it keep rotating",
"Is exactly what will happen. I attended a talk describing an experiment where they did that. But one caveat, you actually have to 'pin down' the motion of the ... | [
"What exactly does \"ignore friction from surfaces when at extremely low temperatures\" entail? In particular, supppose I have a tube filled with superfluid liquid helium, and I find a way to give the helium an initial spin. Will it keep rotating (with adequate cooling, etc) indefinitely like a ",
"superconductin... |
[
"Can daily sunscreen use make you more vulnerable to the sun?"
] | [
false
] | It is to my understanding that UVA radiation is what triggers melanocytes to produce melanin. My skin is relatively tan naturally and growing up (Los Angeles) I rarely applied sunblock and never got burned. When I was 18 i started working outdoors for 9 hours at a time and noticed I began to develop sun burns; as a result, I did some googling and started applying sun block daily. Its been about a year now since I started applying daily sun block and it seems as if any day I don't apply it my skin burns. Growing up I could go hours and hours in the sun without being burnt and now I burn incredibly quickly. Is this a result of permanent damage done to my skin through the years or is this a result of my daily use of sunblock preventing melanocytes from producing the bodies natural sun block, melanin? tl;dr Does sunblock prevent melanin from forming, therefore, making you weaker to the sun when you do not apply sunblock | [
"Sunscreen doesn't make you more prone to burning, but being pale does. ",
"That said, as public service advertising has drilled in to me (Aussie) for as long as I can remember, \"tanning is skin cells in trauma, theres nothing healthy about a tan.\"",
"So while consistent sunscreen use can make you more pale, ... | [
"But for skin damage including cancer - no. That's a lifetime exposure risk, and is not related to burning.",
"Are you sure about this?",
"Here is a nice paper",
" on the relationship between severe sunburns and different types of skin cancer. They have a nice sample size: 87,166 women and 32,959 men.",
"I ... | [
"Not really. ",
"If you are pale, you are at risk of being burned, sure. Stay pale, maintain risk of burning when you forget to wear sunscreen. ",
"But for skin damage including cancer - no. That's a lifetime exposure risk, and is not related to burning. The melanin in your tan is not protecting you from skin c... |
[
"Can things fall after a long time without being disrupted at all?"
] | [
false
] | [deleted] | [
"If something isn't falling now, but then is falling later, something had to make it fall. It won't necessarily take much: a light breeze, or some internal change in the structure of the object itself. For instance, stand a hardback book on end. It's held together by glue and stitching. Over time, the chemical prop... | [
"It's almost certainly either a vibration or a rogue air current that's causing something to fall. It hasn't been \"falling\" for a few days, if that's what you are asking."
] | [
"I thought I'd just add the idea of ",
"static friction",
" here.",
"As the other replies stated, some external factor would start the object moving. If a small gust of wind (or something similar) was able to overcome the static friction the object is likely to keep on sliding until it falls."
] |
[
"Negative pressure/space?"
] | [
false
] | Would it theoretically be possible to create negative space? Say you had a box made of diamond, attached to the most powerful machine on the earth that allowed the box to expand. If you created a vacuum in this box and then tried expanding the box, what would happen? Sorry if this is a dumb question, and I know you can't have negative pressure, but what if you tried??? | [
"There would still be a vacuum. A true vacuum means that there is zero matter in the box. Even if you made the box bigger, there would still be zero matter, and thus still a vacuum."
] | [
"I just feel the need to point out that diamond is hard in the sense it scratches everything else. You could easily shatter a piece of diamond with a hammer."
] | [
"Something does change, though - if your machine could stretch the box, and there is an atmosphere outside the box, you would wind up with a box with more force pushing in on it. (The outside area of the box has increased, and the outside pressure is the same).",
"If you keep going with enough pressure and a weak... |
[
"Why do the helium balloons hit the deck when everything else is in freefall on the vomit comet?"
] | [
false
] | Whats going on with the balloons in from the vomit comet. As soon as the aircraft is in free fall causing everything else to float around the aircraft, the balloons seem to loose bouncy and do the opposite. | [
"This is one of my favorite physics demonstrations. The answer is buoyancy! It's the same reason a helium balloon in your car gets pushed ",
" when you accelerate and backwards when you brake.",
"Think about it in terms of the way gravity normally works. When the acceleration points down, the balloon goes up... | [
"You're right, nothing should move if the plane is in ",
" free fall. But any deviation is going to cause motion. I can't watch the video at work, but I'm guessing at some point the passengers of the plane float up due to slight negative g... the balloon should go down correspondingly."
] | [
"It's partly right I think. If effective gravity went negative, this is indeed what would happen. Here's a zero g explanation:",
"The heavier air normally sits at the bottom, letting the lighter helium bob up top. These balloons are anchored with strings, which the buoyancy places under tension. If gravity sudden... |
[
"Why do proline residues slow protein migration in SDS-PAGE?"
] | [
false
] | But, based on calculations from its amino acid residues, p53's mass is actually only 43.7 kDa. This difference is due to the high number of proline residues in the protein, which slows its migration on SDS-PAGE, thus making it appear heavier than it actually is.[7] This effect is observed with p53 from a variety of species, including humans, rodents, frogs, and fish. From . What is it about proline that does this? Is this only observed in p53? Thanks I'm advance. | [
"So polyacrylamide gels are basically long linear chains of a polymer which are cross linked. The cross linking between the linear chains takes something that is originally like two sticks standing next to each other and turns them into a ladder. And the entire gel isn't just one ladder, it's a massive field that's... | [
"''It also has a funky angle which essentially equates to a kink in a chain that can't go away''. That's the important part right there. Most amino acids are fairly linear when you look at it, but think of proline as a rigid kink in your 3D structure. You find them in B-sandwich structures because they allow that '... | [
"as proline has the fixed angle as mentioned, the denatured protein will have a more extended \"random coil\" conformation and therefore have lower mobility in SDS-PAGE, thus appear to have higher MW."
] |
[
"The NTSB wants to lower the drunk driving BAC standard to .05: Is this change significant enough that it would change the ability of the brain to process information?"
] | [
false
] | Biologically, what is the difference between a BAC level of .05 and .08? | [
"Without doubt, there is an enormous difference in the cognitive effects of alcohol between 0.05% and 0.08% blood alcohol concentrations (BAC). Different cognitive tasks are sensitive to very different levels of alcohol; ",
"some are severely affected at levels as low as 0.02%, while others are relatively insensi... | [
"I'll assume you mean 0.05, since 0.5 is potentially lethal! :)",
"Countries with the 0.05 limit generally recommend the following upper limits: ",
"Two standard drinks in the first hour and then one standard drink per hour after that for men",
"One standard drink per hour for women",
"A standard drink here... | [
"The most basic rule of thumb is that one standard drink, administered in bolus (i.e., at once), would raise your BAC 0.02%, and your body would eliminate about 0.02% per hour."
] |
[
"How would an isolated pile of neutrons behave?"
] | [
false
] | Neutrons are shot off in every direction during a fission reaction; is it possible to keep them separate once they have? The properties of isotopes seem to indicate neutrons in an atom don't have much of an effect on its chemical properties- Would a pile of loose neutrons have no response to magnetism? Would it behave like a fluid? What color would it be? | [
"They would decay to protons with a half life of around 10 minutes."
] | [
"Would they just mostly pass through solid matter? "
] | [
"Wouldn't they stick to the atom's nuclei of whatever container/table you rested them on - creating a bunch of strange extra-neutron-heavy isotopes?"
] |
[
"What year is this?"
] | [
false
] | [deleted] | [
"Just use ",
"Julian Days",
" and apply conversions from Julian Days to the various calendars, both current and historical.",
"What I am saying is other people recognized this problem and established the now-standard solution -- Julian Days."
] | [
"How does this obvious suggestion merit a downvote?"
] | [
"I've been looking around for any research that really gets in-depth with comparing the chronology of western culture and its calendars with tree rings and radiocarbon dating.",
"You don't really have to do that - tree rings and radiocarbon dating are hard to use to get to a precise year.",
"Although it might s... |
[
"In light of the recent growth of sightings of Tasmanian Tigers and possibility of a species coming back from what we thought was extinction... Has this happened with any other species in the last ~500 years?"
] | [
false
] | Question in title. Just curious if other species have rebounded that we are aware of. Thank you in advance. Edit: Really interesting answers by everyone so far. Thank you! Edit 2: Follow up question. What are the biological implications when a species that we thought was extinct, rebounds it's population? Is it just limited to things like focusing on changing what caused their extinction in the first place, like eradicating the rats in the "tree lobster" article? Edit 3: Holy cow ladies and gents. I never thought I would get this much feedback on my post. It's going to take me a bit to read through it. But I will. In the mean time, thank you again, from the bottom of my heart, for all your answers and feedback. Edit 4: Here are a couple links that led me to believe that the sightings had increased and were credible enough to be taken seriously by scientists. (copy/pasted from a buried comment) Here is a different which I read a couple days ago that prompted me to think that the number of sightings have increased recently. In the article they mention several recent sightings and the fact that there is a team of scientists taking action to further investigate the claims. More information on the scientists conducting the research can be found in a media release from James Cook University. Dr. Sandra Abell and professor Bill Laurence will be leading a team of scientists that will be placing 50 wildlife cameras out in strategic locations to try to catch a glimpse of the creature. This is part of an already existing study that they were conducting to monitor wildlife that had been modified to focus on the Tasmanian Tigers following the credible sighting reports. | [
"Black footed ferrets from the US and Canada were declared extinct in 1979 due to farmers poisoning prairie dogs, their food supply. Lo and behold, a farmer's dog brought home a dead one 2 years later and they became endangered instead!"
] | [
"Yes, this happens quite often, although you will hear more news about animals like tigers since they are more popular. There is also the issue of deciding when to declare an animal extinct. Many birds are elusive and haven't been sighted in years. From a quick search here are some animals thought to be extinct but... | [
"The tree lobster story was fascinating. Thanks for sharing!"
] |
[
"What's a career for PhD outside of academia like?"
] | [
false
] | I was reading thread hoping to find some descriptions of science careers outside of academia, but to little avail. My question is: What types of career's (in science, hopefully) are available to PhD holders outside of academia? I just finished my undergraduate in engineering and entering a graduate program in biomedical engineering come fall. However, academia has never attracted me; if anything, I feel quite the opposite, especially after reading . Thus it has been my plan to jump ship to industry after finishing my PhD; However it is my impression that this is the uncommon route for most people entering graduate school. Can anyone relate their stories of non-academia careers, and how or why? | [
"Not to be rude, but this is completely false. I know ",
" few (domestic) master's students in my graduate chemical engineering program--there's a good reason for that. Unless you already have a job, which is paying for your master's program, there is no reason to get that degree. You'd be competing for the sa... | [
"Still at the conference, so I can only drop short comments, right now a chemical engineer is talking, so I am doing this to keep from falling asleep. (sorry chemEs but reboiler calculations are super dull!) any how, don't believe that whole line about engineering phds not being worth anything in industry, it simp... | [
"I laid this out in my other comment, but I figured I'd give you an orange letter--In my ChemE department, about half of people end up in industry, a quarter in government, and a quarter in academia. There's absolutely nothing wrong with going into industry, and there are plenty of jobs in R&D and processing that ... |
[
"Is there such a thing as a \"pure\" note?"
] | [
false
] | The same pitch has a different tone quality on different instruments. Is there anything that's considered to be a "pure" note, meaning it doesn't sound like any one thing and is just the pitch? | [
"To put it simply, no. We divide a note into \"pitch\" and \"timbre\". \"pitch\" is often simplified as being the frequency, but in reality it isn't necessarily all that related, there are a lot of things that can produce a pitch.",
"But the more fundamental problem is that, even we accept the frequency-based d... | [
"The most important thing to understand is that almost every sound you hear is made up of many, many different frequencies. ",
"What makes a middle C a middle C is its \"fundamental frequency\", which for middle C is just over 261 Hz. Playing that note on a piano, or a guitar, or any other instrument will produce... | [
"Playing that note on a piano, or a guitar, or any other instrument will produce an oscillation at 261.625-etc. Hz. ",
"That is not necessarily true. You can have \"middle C\" without any sound anywhere near 261 Hz. There are a number of ways to get sounds of a particular pitch without having any sound energy b... |
[
"What happens to circulation after a limb has been amputated?"
] | [
false
] | I know normally it would go in a circuit down to the end of the extremities and then back up to the heart and lungs to be for gas exchange, but what happens to circulation once that pathway is no longer there? | [
"This is generally correct (I say 'generally' because of the use of \"series\" which I will discuss later), but I think this might be above OP's level of understanding so I will elaborate. Blood typically flows through capillaries to get from arteries to veins, not directly from what you might think of as a normal ... | [
"You need to keep in mind that the body is a series circuit. This means that at every point blood flow is branching off to serve tissue. The arteries that feed the foot also feed the leg and so on. Basically, they anastamose or close large vessels at the stump, before sealing it. "
] | [
"I totally meant parallel and screwed up my analogy.",
"I spent like, 10 seconds trying to remember which was which and didn't bother to google to confirm, so thank you sir!"
] |
[
"What's up with pubic hair?"
] | [
false
] | null | [
"Disclaimer: I summarize some research I've read below, but this is not my area of study.",
"As far as I know, it would be fair to say that the answer to this question isn't fully understood. The general outlines: it seems not to be the case that pubic hair was specifically evolved, but rather that it was selecti... | [
"While it may seem that humans have more hair around the pubis than other parts of the body, this is actually not true. We have approximately the same density of hair follicles over most of the surface of our skin except for the bottoms of our feet, palms, and the skin closely surrounding these two areas. I'm sure ... | [
"What would happen to a person that comments the correct answer but lacks the expertise and source?",
"For example, I know of a suitable response for OP's question. However, I'm only regurgitating what I've learned from my experience as a biology student."
] |
[
"AskScience AMA Series: Colorado State University Unveils The First Human Clinical Study Measuring and Comparing the Absorption Rate of CBD Delivered Through Food & Supplement Product Formats, Ask Us Anything!"
] | [
false
] | null | [
"With no approved use for CBD outside of one medication used to treat intractable epilepsy, how is this kind of study beneficial - outside of marketing information for Caliper?",
"Is that the whole point? You can market your product based on absorption rate because you can't legally market it to treat any disease... | [
"There certainly is a dearth of studies and a lot of claims being made about CBD. This is obviously a rapidly growing industry with a lot of interest. What options do you see to broadly establish trust and quality control? I appreciate that a study was conducted here, but I think people also are generally wary of i... | [
"You list the ingredients for each of the Caliper offerings — does that matter to the final results? Can you isolate ingredients that are offering better absorption?"
] |
[
"Telomerase and cancer"
] | [
false
] | Why is telomerase necessary for cancer cells to divide? | [
"This is a bit of a complicated issue.",
"Technically, telomerase is not necessary for cancer cells to divide, any more than it is necessary for any of your other cells to divide. However, it is good for cells that need to divide a lot, so they can continue dividing.",
"When you replicate your DNA, the enzymes... | [
"I suspect that telemorase isn't absolutely required as fidelity on the chromsomal ends may not be short term issue for a tumour"
] | [
"Active telomerase is ",
" a hallmark of cancer. There are many arrested and neutralized cancers that occur rather frequently in many organisms. Cancer is often a handful of mutations that occur and when those certain mutations occur together you get a virulent immortalized cell line."
] |
[
"What is the difference between sun burns and radiation burns from radioactive material?"
] | [
false
] | Both the sun and radioactive material are producing radiation. I'm curious: If I was near nuclear material, would I begin to exhibit the symptoms of a sunburn before the more serious issues occur? Likewise, if the solar radiation were magnified, could I suffer the same symptoms that one would experience when exposed to nuclear material? | [
"Yes, both are caused by DNA damage. The difference is that UV light that causes sunburn can't quite ionize and break DNA, but it can form ",
"thymine dimers",
" which prevent replication. UV light can't penetrate very far in the skin, so magnifying it won't get you anything but more sunburn. Ionizing radia... | [
"The danger from being very close to a nuclear reactor is actually from neutron radiation, which is difficult to shield against. It tends to thermalize in the presence of any thick chunk of water (i.e., your thighs), which increases its cross-section and causes it to react far more readily with other atoms. It's th... | [
"UV can trigger the growth of skin cancer. Gammas, neutrons, etc., go all the way through, and can start deep cancers. I don't think you can get bone/brain/liver cancer from UV. Maybe leukemias? Does UV make it into the capillary bed?",
"Odd trivia: some alpha-window geiger counters will respond to solar UV... |
[
"How can two different molecules exist in different states at the same temperature?"
] | [
false
] | If temperature is defined as the average kinetic energy of a system, how can one type of molecule exist as a solid and another as a gas at the same temperature, yet the latter is moving exponentially faster? Edit: How can two different molecules be considered the same temp. when one species is moving faster than the other? Edit 2: I don't think I worded this properly, so here is a longer explanation. So, like I said, temperature is defined as the average kinetic energy of a system. With that being said, how can one species of molecule that exists as a solid at temperature "X" be considered the same temperature as something that is a gas at temperature "X" when the species that is a gas is moving much much faster? I understand that different species exist in different states due to intermolecular forces (hydrogen bondering, van der vaals, etc.), but what I don't understand is how are they considered the same temperature? Is solid H2O vibrating just as fast as liquid ethanol is moving at 0°C? | [
"If temperature is defined as the average kinetic energy of a system",
"Because it's not, but it happens to be related to it for an ideal gas. (where the only form of energy/degree of freedom is kinetic motion) But real substances can store energy in intermolecular bonds (forming crystals and liquids), as vibrati... | [
"Temperature is ",
" defined as the average kinetic energy of the system. The definition is much more general, and is related to how much entropy a system will gain or lose when some energy is added or removed. Loosely speaking, for normal systems (forget exotic situations that can have negative/infinite temperat... | [
"When you talk about a phase change you need to consider the fact that these particles are interacting. In a non-interacting theory (i.e. ideal gas), the temperature is directly connected to the average kinetic energy of the gas molecules.",
"Now let's turn on an attractive interaction; temperature is no longer ... |
[
"How far can germs crawl?"
] | [
false
] | If I pick up a piece of poop, and then use that hand to stir a pot with a metal spoon, will the poop germs get from the end of the spoon into the pot? Germs are really tiny so that's a long way to travel, and they can't build a chain of colonies on a metal spoon, right? | [
"Motility in bacteria is basically reserved to aqueous environments. They can use flagella to swim around in (as I'm sure is clear) very very very small amounts or layers of liquid. Helical bacteria have special structures that let them spin to move. Some bacteria make tiny amounts of gel that let them glide around... | [
"Copper is really really really really good at killing bacteria. Copper door handles and faucets are great. Silver too.",
"Basically all of the metals that are toxic to us are toxic to them, but unlike bacteria, we won't die from touching a copper doorknob."
] | [
"TIL some metals kill bacteria.",
"Related to OP's question: Wash your fucking hands before touching a spoon."
] |
[
"Is it less carcinogenic to vaporize tobacco? What about marijuana?"
] | [
false
] | null | [
"Electronic cigarette expert here. If you're going to vaporize nicotine, you might as well not even bother with the leaf.",
"Nearly all of the carcinogens found in cigarettes are absent in electronic cigarettes. Ecig juice is comprised of propelyn glycol, vegetable glycerine, flavorant, and pharmaceutical grade ... | [
"There are way too many for me to list, but check the wikipedia page - it's pretty comprehensive. The only reason additives are there in the first place is to make tobacco more addictive by altering the way it and the additives interact with your brain chemistry. They don't put stuff like ammonia in cigs to make th... | [
"What are the additives in cigarettes that makes a cigarette more addictive than nicotine alone?"
] |
[
"Salts can screen electric fields. Can they also screen magnetic fields such as in NMR?"
] | [
false
] | Recently I tried to perform a cpmg NMR experiment on a sample with a high salt concentration, about 2.2M. Unfortunately, the experiment didn't work. The technician said that the high salt effectively screened the magnetic field such that the pulse length necessary to pull the hydrogens out of alignment was longer than the decay timescale we were interested in. At first I took his explanation at face value because salts can screen electric fields but I've come to wonder if Maxwell's eqns also predict that salts can screen magnetic fields? Thanks. | [
"Conductive solutions (aka lossy samples) will be heated up by the RF pulses, meaning that instead of manipulating nuclear spin magnetic moments, you're using an NMR spectrometer as a really expensive water heater. Combined with the fact such samples make tuning the probe and calibrating pulse widths a nightmare, ... | [
"Interesting - we did have issues tuning the coil. I'm still wondering about the fundamental physics that causes these types of issues."
] | [
"If the conductivity of the salt solution is high enough you could be having skin depth issues. What is the frequency content of your pulse?"
] |
[
"Is it possible to have loud enough bass to actually cook something, or even have an effect on temperature?"
] | [
false
] | This may seem like a REALLY dumb question, but here's my reasoning: Temperature is based off of molecule movement, and I'm wondering if bass can be turned up enough to get molecules to move really fast. I think it would be cool to cook a burger with a huge bass drop. | [
"I think it would be cool to cook a burger with a huge bass drop.",
"You need to put the energy into air and then have the burger absorb it. ",
"A loudspeaker has very low efficiency of putting power into the air. And a hamburger has low efficiency of absorbing sound. ",
"A good speaker will put 5% of the inc... | [
"Furthermore, bass frequencies are not absorbed well by burgers. I am honestly not that familiar with sound absorption spectra for most foods, but something a little higher frequency would probably work better."
] | [
"I remember reading at a science museum that the energy released in in a year of continuous screaming is the same as the energy required to boil a cup of coffee. I'm without reference to this due to it not being an online article i can link to but i think it gives some idea as to how large the difference in energy ... |
[
"If the universe is expanding, is the distance between my atoms increasing right now?"
] | [
false
] | The universe is expanding. (At an accelerating rate, so I hear.) Does that mean that the space between the atoms it my body (and on my table, and in the world) is currently increasing? (Also, how do I tag things as #physics?) | [
"Here",
" is a very similar recently asked question.",
"The answer is that the distance between your atoms ",
" be increasing if it weren't for the fact that the forces holding your atoms together, well, keep holding them together. It's like if you stretch out a spring -- the spring doesn't stay stretched out... | [
"The force of dark energy, which is driving expansion, is very weak compared to the force of gravity. So objects like our galaxy, solar system, planet, you, me, etc, are not expanding because gravity is stronger and keeping those objects bound.",
"Expansion happens in deep space between distant large objects - w... | [
"It would be clearer to say ",
"."
] |
[
"Do wild animals get dental cavities?"
] | [
false
] | Does not brushing lead to poorer dental hygiene in wild animals? | [
"Most wild animals certainly get cavities and other forms of periodonal disease, especially with age. That said, compared with people, rates are very low (below 10% in most cases). I guess its not surprising that the frequency of cavities changes with dietary mineral content and with increased sugar consumption - f... | [
"Oh. So dental problems are more related to sugar consumption than not cleaning teeth?"
] | [
"Sugars don't act as acids. It's the lactic acid, the product of fermentation of carbonhydrates by bacteria(mostly streptococcus mutans, streptococcus sobrinus and lactobacilli)"
] |
[
"What was the name?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):"
] | [
"Wait, the first question has been posted? It doesn't show up in my Posts... I have saved this one, but now I have no choice to access the other..."
] | [
"As the submission page states, all submissions are placed in the spam filter for moderator review, so please be patient."
] |
[
"How is it we can use fusion in bombs but not for energy production?"
] | [
false
] | I have a pretty limited knowledge base on this subject so I'm asking anyone who'd care to answer. What's the disconnect between the fusion taking place in a and fusion being used as an energy source? I can speculate about several reasons: safety, lack of control, etc. but all would seem to apply to fission as well and we've managed to figure that one at. If I'm missing something big here feel free to call me out on it. Thanks in advance for your replies. | [
"I work on magnetic confinement fusion, so I can probably answer any question you have on this to any specified detail.",
"The general problem is that for a bomb you want to create a lot of energy very quickly. For a reactor, you want to generate a reasonable amount of energy very slowly and steadily. The way a... | [
"Fusion requires a tremendous amount of energy to start the process. You must push the positive nuclei together, and that requires a lot of energy to do so. Fission is an atom almost ready to break in two, and just needs one last neutron to do so. Much easier to initiate.",
"In addition, one can make a big block ... | [
"Fantastic answer.",
"Are you and your colleagues optimistic that the problems you listed are actually solvable? Or is there a fear in the field that both ICF and MCF are never going to work?"
] |
[
"Why are certain cancers more common than others?"
] | [
false
] | Lung Cancer, Breast Cancer, and Prostate Cancer rank among the most common cancers. Why are cancerous growths more common in these locations than in a place like your arm or brain? | [
"Oh this is a very interesting question. In short, there are more factors than I care to type out now. But to give you an idea I'll focus on two examples:",
"Every cell in your body accumulates mutations randomly across the genome during each cell division. One of the key driving events of cancer is some specific... | [
"Lung cancer is statistically proven to be largely promoted by pollution and exposure to cigarette smoke. This explains the common nature of this particular tissue.",
"However, I’d avoid looking for a pattern, trying to create one, right? Cancer is a complex disease and there’s no reason each tissue should be equ... | [
"Explaining it tissue by tissue is very hard and I don't know enough about these specific cancers to do it.",
"\nIn general, though, cancer is more likely to happen where there is a source of chronic inflammation or where the tissue is exposed to cancer-promoting elements (as mentioned in another comment, polluti... |
[
"When I make tea and stir in some sugar, I notice the sound of the spoon tinking against the side of the mug changes pitch. Why?"
] | [
false
] | Always wondered why this is happening. | [
"The addition of sugar changes the density of the medium (water) which changes the propagation velocity of the acoustic wave through it. A change in propagation velocity is manifested as a change in pitch, all else being equal. You can read this link: ",
"http://music.ece.drexel.edu/files/Navigation/K-12_educatio... | [
"this actually has a name"
] | [
"This is an incomplete explanation. If you try it yourself, you'll notice that the pitch is strongly affected by stirring. I've done this experiment many times with hot chocolate, and the pitch while the liquid is rotating is typically around an octave lower than when it's stationary. The effect is easily reversibl... |
[
"How do we program highly complex cosmological simulation software?"
] | [
false
] | I was watching How The Universe Works on Netflix and they frequently show simulation models of galaxies colliding, dark matters influence on the shaping of of our universe, and many other highly complex simulations. I was wondering how do people design these programs to simulate this? These problems seem ridiculously complex. Does an astrophysicist sit in a room with a bunch of programmers telling them the math or do a bunch of astrophysicists get CS degrees and program it themselves. It seems like such a daunting task I was wondering if someone could shed light on this. Also, I apologize if this has been asked before, I tried the search function and could not find a question similar to this. | [
"Realize that ray-tracing, liquid simulation and a lot of things commonly done by computers is easily equally complex...",
"No idea how that specific program was done, but as a programmer, I've certainly had jobs where I basically had to bunker down for weeks with some complex textbook and convert all the formula... | [
"Sure, and most of that is structuring the code such that the formula's are nicely separated from the main code, so that the mathematician (or whoever) can review them without understanding much of the language or rest of the code.",
"You just send them a snippet and they can work out where the mistakes are or ve... | [
"A lot of scientists learn how to program out of necessity.",
"Whether or not collaboration happens with programmers usually depends on the complexity of the program relative to the scientist's programming skill and study scope/funding."
] |
[
"Why are we so sure that dark matter exist, rather than gravitational models being incomplete/incorrect?"
] | [
false
] | null | [
"See the astronomy FAQ."
] | [
"No, the conclusion has not changed."
] | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"Your question is either commonly occurring or has been recently posted on ",
"/r/AskScience",
". It may also be answerable using a Google or Wikipedia search.",
"To check for previous similar post... |
[
"About how far up would an average helium party balloon float if let go right after being filled?"
] | [
false
] | null | [
"Something I know! I'm not a scientist... or at least I'm a scientist on one specific topic: Balloons. But most people call me a balloon clown because I make animals and toys for kids while dressed up in a funny costume. ",
"Anyway, I usually deal with helium and often liek to send balloons into the sky with lit... | [
"It's just my take on the \"message in a bottle\" but with falling balloons for kids! I like to sparkle up the balloon and the note so that it catches people's eyes. And they are are on all type of topics just as long as they get the imagination going! I can give you some examples of the notes I have for my next la... | [
"often liek to send balloons into the sky with little notes into the sky hoping that a child finds them and let their imagination run wild.",
"This is the most adorable thing I've heard all day. Has a child ever found one of your notes, to your knowledge? What kind of things do you put in them?"
] |
[
"Do other animals understand and comprehend photos/videos?"
] | [
false
] | null | [
"Some of them certainly do, but it's hard to say exactly how many just based on a lack of existing research. It's been clearly demonstrated that Rhesus monkeys pay attention and respond to videos of other monkeys in similar ways to how they would react to seeing them in real life (",
"Mosher et al. 2011",
"). ... | [
"Interesting!",
"A few questions if that's okay:",
"In Deaner (2005), I can understand, at least intuitively, the reasoning for trading food for the pornography, but I'm not sure I understand why they would trade good for individuals of social status. Unless I'm misunderstanding, are these same-sex individuals ... | [
"I know a cat will see a recognizable image in a TV. We once had a feral cat that because of his being born in a field, was deathly afraid of black birds, like crows. Well one day we were watching a nature documentary and when they showed a big black bird opening its wings, the cat went ballistic and tore around th... |
[
"Are Pandas worth the conservation effort?"
] | [
false
] | It appears that these creatures get an unfair amount of coverage, attention and money for preservation when they aren't designed to survive as is. They don't want to reproduce and have a narrow diet spectrum. Why should they be preserved at such a cost, when that money could be diverted to other ecosystems that have a better shot at survival? | [
"Pandas are perfectly well designed to survive, and want very much to reproduce, when they are in their original habitat (large swaths of broadleaf forests of SE Asia). It's only in captivity, and when the forests get really fragmented, that they have problems. ",
"The bigger picture though is that panda conserva... | [
"I don't think your question is really one science can answer, so please excuse my casual, non-scientific answer. ",
"My friend who worked at the san diego zoo told me many people go there primarily to see the pandas. In other words, free-market: people like pandas, so they are willing to pay more money to preser... | [
"From the WWF site \"That is one of the main reasons why they are so important: by mobilizing people to save the panda, we are actually helping preserve the rich biodiversity - plants, landscapes, other animals - that need to be there in order for the pandas to survive.\"",
"So they also said that the panda is a ... |
[
"Since the earth is in constant orbit around the sun, how come we do not feel any effect from the centripetal acceleration?"
] | [
false
] | null | [
"We don't feel the centrifugal force due to the motion of the Earth around the sun because it's very small.",
"We don't even feel the centrifugal force from the Earth rotating about its own axis, which is much larger."
] | [
"Good point. I hadn't thought about that. I guess then for the second question it is highly unlikely it would change anything?"
] | [
"Correct."
] |
[
"How far ahead in the future can we (accurately) predict the weather?"
] | [
false
] | I had a teacher once say that any forecast ahead of 10 days was mostly just BS. How far ahead can meteorologists predict with 60% accuracy? | [
"Weather systems tend to be chaotic (Complexity Theory). This means that there may be sensitive dependence on initial conditions. At other times it means the system will behave in a predictable fashion for a period of time and even fairly hefty nudges won't make much difference.",
"When modelling weather one appr... | [
"Your teacher was right. Although forecasting has really gained accuracy in the past 50-60 years and we're able to see way more than we could before (using models, the most common being the MSL model, used by most newscasts. NEXRAD is also a popular choice (GOES satellite imaging is used as well)), it's still not a... | [
"If this is so (and it sounds right), can a meteorologist tell us why forecasts don't come with accuracy ratings attached to them? "
] |
[
"How do changes in an entangled system propagate?"
] | [
false
] | [deleted] | [
"You and I live a mile apart. A thunderstorm rolls through, and at precisely nine o'clock, it starts to rain. It rains for a while, maybe with the occasional peal of thunder, then stops.",
"Later, I happen to run into you around town. \"Some thunderstorm, hm?\" I say, making conversation.",
"You are amazed. \"H... | [
"Well, another analogy might help further the point. ",
"Imagine there is a box that contains two marbles, one solid red and the other solid blue. You and I are hanging around and the dude that has the marble box asks, \"Hey, want a marble?\" ",
"Sure, why not. ",
"So, without us seeing, he puts the... | [
"No."
] |
[
"Why is there an nth root symbol when you can just write it as an exponent?"
] | [
false
] | null | [
"The nth root of a (positive) number, A, is the positive root of the equation x",
"-A=0. The exponent A",
" is the evaluation of the exponential function of base A at the value 1/n. They are two different things, but it just so happens that you can show they are the same. But, if you care about the equation x",... | [
"Defining ",
" roots in generality is a mess. Even in the complex numbers, most numbers have ",
" different ",
" roots. It's pretty much only in the nonnegative real numbers where you can say that a number has a unique nonnegative real ",
" root.",
"For example, in the quaternions, -1 has ",
" square ro... | [
"Are they guaranteed to be the same in any algebra, or is this something that is specific to the real numbers only? Does nsqrt(A) = A",
" still hold if A is a matrix or a quaternion, for example?"
] |
[
"How many senses do we have, I have heard there is more than the five children get taught"
] | [
false
] | I know there is more because if I spin in a chair and try to stand up one of my senses is screwed up but it ain't one of the main five. EDIT: Dammit bad grammar in the title, pls don't be too cruel | [
"Humans have more than five senses. Although definitions vary, the actual number ranges from 9 to more than 20. In addition to sight, smell, taste, touch, and hearing, which were the senses identified by Aristotle, humans can sense balance and acceleration (equilibrioception), pain (nociception), body and limb posi... | [
"Feeling of suffocation."
] | [
"Smell touches your nose, light touches your optic nerve, etc. Touch is too broad."
] |
[
"How do we 'hear' memories, songs and voices in our head? Do the ears intervene somehow or does our brain reproduce sounds 'internally'?"
] | [
false
] | null | [
"The brain reproduces sounds internally. Although there are signals sent from the brain to the inner ear, these are used during active listening, not during imagination. You can stimulate parts of the brain and produce sensations of sight and sound without neurons in the eye or ear becoming active."
] | [
"Yep. All conscious experience is the result of brain activity -- your sensors, whichever ones, ultimately activate neurons in your brain which are what cause the experience. If you somehow can stimulate them while bypassing the sensor, you'll have the same experience/sensation. Hallucinations are an example of exp... | [
"So, you mean that it's just brain signals somehow making us hear sounds? That's interesting. Thank you! "
] |
[
"Do deaf people still feel pain when they're exposed to really loud sounds?"
] | [
false
] | null | [
"The discovery of how we get pain from loud sounds is surprisingly recent--like 2015. There's a separate set of nerves that run from the hearing organs in the inner ear that seem to just be for reacting to sounds loud enough to cause hearing damage. We don't really understand how it works.",
"There are many, many... | [
"We...don't know. Sorry! Might have something to do with the neurons in the ear becoming too sensitive and \"turning up the volume,\" but there's not too much hard evidence AFAIK.",
"https://www.karger.com/Article/Abstract/430459"
] | [
"Thanks for the answer! That's really interesting"
] |
[
"Do photons accelerate??"
] | [
false
] | Had a doubt... When you switch on a light source, do the photons emitted accelerate to the speed of light or do they go from zero to c instantly?? | [
"The photon is always traveling at the speed of light. When a photon is emitted, it is already traveling at the speed of light. ",
"An interesting addition to your question is that photons can be deflected by gravity. Even though it won't change their speed, strong gravitational potentials can bend the path of li... | [
"The energy of the light wave remains constant as it transitions between media. What changes is the velocity and wavelength. As an example, when light enters glass it slows down which on its own might imply energy loss, ",
" the wavelength of the light also decreases (recall that for light shorter wavelength = mo... | [
"Follow up question. When light travels through a medium, like glass, it slows down. I've even heard some guys were able to slow down the light pulse to a walking speed. When light exits the other side, does it somehow pick up it's energy to speed back up again? It doesn't seem like it does, so how/why does it spee... |
[
"Questions about High and Low Explosives?"
] | [
false
] | First, I am not trying to make an explosive device, I am purely curious as to the chemistry and how they explode. I understand that gunpowder is a low explosive, so it would need to be pressurized to make an explosion, so thats why it is good as a propellent for bullets. But I have some questions... | [
"Do high explosives, such as tnt or picric acid have to be contained or pressurized for them to explode or do they explode if they are just on a plate since the pressure and the explosion is so fast?",
"High explosives have a \"minimum critical diameter\" below which a detonation wave will not propagate. Confinem... | [
"TNT is hard to detonate. Generally, a blasting cap is used. Usta be mercury fulminate, but maybe it's now lead azide. Same materials used in cartridge primers. Those are called \"primary explosives\", and turn a flame instantly into a detonation. ",
"Militaries filled shells with molten TNT, melted in stea... | [
"HEs are specifically designed to not be shock sensitive (detonable by shock force e.g. dropping, throwing, impact in general) and therefore generally cannot be used to detonate one another. Most often electric fuses are used."
] |
[
"What are we processing when we see color? Frequency, or Wavelength?"
] | [
false
] | Lets take for example, a beam of red light, passing from air, through a glass block 1m wide (irrelevant) and out into air again at 90 degrees. We can see the beam clearly through all of this. From my understanding, because the light slowed down in the glass, but frequency remains constant, the wavelength must have changed to compensate, but I asked my Physics teacher (im in Australian Year 12 "senior year") and he said that the colour we will see in the glass will be the exact same as the colour in the air, because to humans, colour is a frequency property, I understand it a little using a Doppler effect analogy, but then why do we use wavelength so much to describe colour? Thanks all! | [
"From my understanding, because the light slowed down in the glass, but frequency remains constant, the wavelength must have changed to compensate,",
"No, light always travels at c, but when it passes through a medium other than a vacuum the atoms in the medium absorb and re-emit the photons which takes time and ... | [
"Because when it exits the glass it changes again to the exact same color it was, since the change is from air to glass and back to air, once it goes back to air and sends the photons to your eyes they are the same wavelength they were originally. ",
"Edit: Because the medium of the eye is unchanged (barring seri... | [
"That's not quite right. Although you are correct that there is an absorption and reemission process going on, the situation is a bit more complex, because photons are wavefunctions that represent excitations of the electromagnetic field, not billiard balls.",
"If you take a small resonator and inject some broadb... |
[
"If the US paid of every penny of its debt and the government made more mean income than they spent how would this effect the US and the world?"
] | [
false
] | null | [
"Such hypothetical / speculative / open-ended questions are better suited for our sister-sub ",
"/r/asksciencediscussion",
". Please post there instead."
] | [
"I've been trying to 'correctly' post this for 10 minutes then you say it's the wrong sub"
] | [
"I've been trying to 'correctly' post this for 10 minutes then you say it's the wrong sub"
] |
[
"how did we prove that all atoms have a gravity well if it's too tiny to measure?"
] | [
false
] | How do we know there isn't a little lump of "Gravitonium" at the center of each celestial body and that all the gravity we measure is a result of that un-seen object? What would it mean if we discovered that mass does NOT create a gravity well, it's merely affected by one? | [
"We can certainly measure the gravity of small bodies. The historical ",
"Cavendish Experiment",
" used torsion balance to measure the gravitational effect of a 158 kg lead ball.",
"That is certainly not the same as measuring the gravitational effect of single atoms, but it disproves your hypothesis of Gravit... | [
"photons can be the source of gravity",
"Do you know if there have been observations of that? I know that they should but I didn't know if it had been observed or not"
] | [
"The reverse effect (photons being affected by the gravitational force of large objects) is known as Gravitational Lensing."
] |
[
"How do we know that the age of meteorites correspond to the age of the earth?"
] | [
false
] | [deleted] | [
"Earth has never been directly dated (rocksinmyhead will come in here and post about an attempt using Lead to do it and that is a valiant effort). For now the best way to think about it is as follows:",
"Here is a brief history of our solar system",
"1) A long time ago a molecular cloud collapsed (probably from... | [
"Now I feel obliged to post about Clair Patterson's dating of the Earth using lead isotopes... but will simply give the ",
"Wiki link",
". His age of 4.55 Ga is still our best estimate. However, to my mind the age of the Earth is the same as that of meteorites: 4.567 Ga."
] | [
"Thanks for posting that I forgot who did it, I just remembered you posted it. About the age of meteorites though you should subtract idk 10 or 20Ma for formation time to get a nice age. Which gets you back to 4.55Ga which simply amazes me that his technique is so nicely on."
] |
[
"There's a petition in my town to legalize raising backyard chickens. I know this sort of thing is becoming more popular, but aren't there significant public health risks to raising chickens (or livestock) in populated areas? Are there any good studies about this?"
] | [
false
] | null | [
"Essentially what it says is that salmonella can be spread but you have to be directly in contact with the chickens' range, so if they are kept in a chicken run and a coup, the other areas outside of that won't have much salmonella contamination.",
"The salmonella is spread through chicken feces and can get on th... | [
"This publication pretty much covers it. In summation: chickens can carry diseases like salmonella, however the risk is mainly to children, the elderly, and those with compromised immune systems. As far as the issues surrounding things like avian flu, most cities that allow backyard chickens only allow up to 3 or 4... | [
"Yes, there are risks of bacterial/disease transmission. ",
"Here is an \"informative brochure\" type thing from the CDC."
] |
[
"When someone suffers from Acute Radiation Sickness they go through a \"latent\" stage where they feel well and healthy, despite potentiay lethal physiological damage. How is this?"
] | [
false
] | null | [
"If you get a sufficiently high exposure, it kills pretty much all of the bacterial fauna in your stomach and intestines, as well as your intestinal lining. Your digestive system just stops working. That manifests itself as rapid onset nausea, vomiting, and diarrhea. Once you're ah, empty, you feel better. No more ... | [
"Until the cells start to replicate or stop working, most of the damage won't be noticed by the body. A cell has enough proteins to keep functioning for a while. However once cell replication begins and cannot be completed, the cells begin to die without replacement, which leads to organ failure"
] | [
"Unfortunately no, at least we don't know if any way to repair the damage. Acute radiation poisoning does severe damage to DNA which is what causes everything to stop working. CRISPR may be able to repair small sections of DNA in the future, but this sort of damage is too widespread and too random to be fixed by ... |
[
"What causes the graphite in nuclear reactor to become radioactive itself? Is it due to neutron radiation from the uranium fuel breaking apart the atoms of the graphite and causing them to become unstable?"
] | [
false
] | null | [
"Yes, the neutrons transmute nuclei within the graphite such that they are radioactive."
] | [
"Interesting. Does that mean that the effectiveness of the graphite as a moderator decreases?"
] | [
"Not significantly, because a tiny fraction of the nuclei inside the graphite get transmuted. The main effect is that the graphite can be lethally radioactive after being removed from the core."
] |
[
"[Mathematics] How would one construct this?"
] | [
false
] | null | [
"Not the right sub. "
] | [
"Can you point me in the right direction? "
] | [
"You could try ",
"/r/math",
" or a problem/riddle specific sub"
] |
[
"Does epigenetics contradict modern evolutionary synthesis? Why or why not?"
] | [
false
] | Many people have tried to argue with me that epigenetics somehow makes the importance of 'genetic frequency' redundant, because environmental factors influence genes in across lifetimes. I haven't read any expert arguments on the subject. Can someone who is well informed on this issue shed light on it? Is this a muddled topic or is there a clear scientific understanding of this issue? | [
"Even the enthusiasts of things like epigenetics and plasticity, who claim that we need an extended evolutionary synthesis, don't claim that gene frequencies are somehow rendered irrelevant. There's a good review paper ",
"here",
"(PDF) by Massimo Pigliucci, where he argues that we do indeed need a new synthesi... | [
"This is a great resource, thank you."
] | [
"it's not that their irrelevant, it's that their effects are way over-interpreted, and there are so many vested interests in genetics that epigenetics has been sidelined for years. Until the biotech industry bubble pops, you won't hear about it. Read Jabolnka and Lamb, it's a great book."
] |
[
"I found a rock on the side of the road. Without using carbon dating, what is a reasonable estimate of the age of this rock?"
] | [
false
] | [deleted] | [
"If you have an approximate location, and you can approximate the type of rock, you can look at a geologic map of the area and come up with a fairly good idea of what it is and how old it is. If you have a piece of sandstone, a microscope, and a good idea of microbiology, you can look at the micro fossil assemblag... | [
"Carbon dating wouldn't help, it only works back to around 60,000 years, and rocks don't always have high amounts of carbon.",
"You would need to use another form of ",
"radiometric dating",
"."
] | [
"The oldest known rock is a gneiss from Canada that is about 4 billion years old. So, we can knock 500 million years from your estimate ;)"
] |
[
"Why did intelligence only evolve once?"
] | [
false
] | It is obvious that humans dominated the animal kingdom due to their intelligence, thus, making it a huge evolutionary advantage. So why didn't other species became intelligent? | [
"I would argue that intelligence is a continuum, not a single characteristic, and that many different animals have evolved to high levels of intelligence, relatively speaking. ",
"Humans might be at the top of this scale, however other animals, such as our primate cousins, cetaceans, and some birds certainly exh... | [
"It is incorrect to claim that intelligence only evolved once. There are many intelligent species from different branches of the tree of life. Primates, dolphins, elephants, dogs, and even cephalopods are arguably intelligent to some extent. Humans certainly take that particular trait to an extreme, but so what?... | [
"I would argue that intelligence is not by any means the single best evolutionary strategy. We're doing well, but so are plenty of other organisms. Intelligence is one survival strategy of many, and is only beneficial in that it results in higher reproductive and survival rates. Other species have evolved other ... |
[
"Why are clouds flat on the bottom?"
] | [
false
] | Not all are, but I'm assuming the ones that aren't are too high up to be flattened | [
"Clouds form at different temperatures, depending on the amount of water vapor the air contains. In most of the atmosphere, the temperature of the air decreases with altitude. (Temperature inversions, where the temperature of the air increases with altitude, are the exceptions.) So the bottom of the cloud is at the... | [
"Most clouds have flat bottoms according to where the condensation level lies within the air column. The condensation level is the point at which air reaches saturation, and the temperature of the air matches the dewpoint temperature. As air gains altitude, rising through the air column (save temperature, surface, ... | [
"The other explanations are good but I'll chip in too. ",
"All clouds, except fog, are the result of air that rose, cooled down due to expansion, and condensed.",
"\nThe clouds with flat bottoms are called \"cumulus\" and they are a result of air that rose from the ground (",
"convection",
"), cooled down ... |
[
"Why is it that portable chargers above a certain mAh cannot be brought on the plane?"
] | [
false
] | I was on a plane lately and they took away my 50000 mAh power bank :( | [
"Because it is a fire hazard. 50000 mAh for a 5V charger is about a million joules (250 watt-hours), i.e. if there was a short circuit such that the power bank dissipated its energy over the course of a minute (say), it would be putting out 15000 watts (the equivalent of 10 electric stovetop heating elements). A fi... | [
"Lithium ion battery chemistry in particular is dangerously volatile and there's a real chance that a broken or low-quality cell will spontaneously catch fire and burn ",
". There have been several incidents in the past years where a passenger's phone battery or a small power pack has started smoking or caught fi... | [
"Thank you! I understand now"
] |
[
"Is there a specific equation or method to determine an element or compound's state of matter at a certain temperature and pressure?"
] | [
false
] | I know the states of matter and how they work. In organic chemistry my teacher often states something like, "this compound typically exists as a liquid." So I was wondering if this is just common knowledge for certain compounds, and if not, what way there is to determine its physical state besides forcing conditions upon it. | [
"Yes, there is. They're called ",
"phase diagrams",
". Essentially, people already did the tests you're talking about on a wide variety of materials for other people to use.",
"As for equations, you're looking for the ",
"Clausius-Clapeyron relation",
". It's a partial derivative of pressure and temperatu... | [
"But of course, the values of dP/dT are themselves estimates at best without using empirical observations."
] | [
"The chemical potential of the different phases can give you a pretty good indicator of which phase should dominate at a given temperature and pressure, but getting these is not away so easy. "
] |
[
"Since the Sun is travelling around the Galactic Centre at 828,000 km/hr, if we travelled the opposite way the orbit is flowing, towards another star, would we get there faster than if we travelled to a star an equal distance away, but ahead of us in orbit?"
] | [
false
] | I apologize if I asked that in a confusing way. I can try and clarify if needed. | [
"Yes, but what about the star you're aiming for coming at you at (for the sake of argument) around 828,000km/hr?",
"It's not. It's also orbiting the galaxy at roughly the same speed as the sun, meaning that it's not moving toward or away from us. ",
"Think of it in terms of standing in the aisle on a bus. If ... | [
"No matter which direction you leave the solar system in, you start with the same velocity, relative to the galactic core, as the sun (slightly modified by the velocity of the Earth's orbit).",
"So it makes no difference if you travel forward or backward relative to the sun's galactic orbit. Either way, you'll h... | [
"Yes, but what about the star you're aiming for coming at you at (for the sake of argument) around 828,000km/hr?"
] |
[
"Is there a type of plant that can \"plug itself into\" another plant's root system?"
] | [
false
] | [deleted] | [
"Parasitic plants",
" do exists and they use their host's vascular system to obtain nutrients. The vascular system consists of xylem and phloem which transport nutrients and water throughout the plant. \"A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in... | [
"Mycorrhiza from one root system can also fuse with the mycorrhiza of another root system. "
] | [
"commercial cloning of japanese maples involves grafting the tree onto more aggressive trees root systems..."
] |
[
"Giant plate of stone on water."
] | [
false
] | Hey askscience, I had a flashback to an idea I had when I was washing the dishes as a kid. I'd always spin the floating dinner plates, make waves in the sink and make the plate sink eventually. Anyhow, I remember me one day wondering: "**If one would place an enormous dinner plate (i.e. a somewhat concave object made of stone; let's say 1 mile radius) in a giant pool of still water, would it still float like a dinner plate would in a sink full of water, or would the weight eventually become too high so it would sink? And would it make any difference if it were spinning or not? Thanks! | [
"Yep. Float just like a plate. ",
"What determines this is how much water is displaced. If you think of sitting a dinner plate in the water and then freezing the water and taking the plate out, you have a little concave area. If calculate the volume of the concavity it equals the weight of the plate. ",
"See "... | [
"Eureka! My kid self KNEW this!"
] | [
"Same way a ship, built of heavy metal, loaded with cargo, manages to stay afloat. The weight of the water that it displaces weighs more than the weight of the ship. Two ways are available to increase this ability. Increase the size of subject vessel, or decrease it's weight."
] |
[
"In getting your daily water requirements, is it the same to chug 32oz twice (assuming you can keep it down) or to sip on 64oz throughout the whole day?"
] | [
false
] | null | [
"It would be better to sip it over the course of the day. When you ingest a large amount of water, your body will signal the kidneys to excrete the excess to regulate your blood pressure and balance out the concentration of fluids to solutes throughout your body. "
] | [
"Its dangerous to drink more than a quart and a half of water in under an hour and a half or so... this depletes your body of its electrolytes and can lead to water toxicity"
] | [
"It wouldn't lower your blood pressure, but the increased water content in your blood and intracellular fluid would dilute the concentration of solutes (like sodium or potassium) in your blood, which would cause chemoreceptors in your kidneys to allow more water to be filtered out to restore tonicity. ",
"If you ... |
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