title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"When transition metal ions absorb visible light of certain colours wouldn’t they de-excite to emit photons of the same colour?"
] | [
false
] | null | [
"Not necessarily. For example if you excite an electron from level 1 to level 5 it could just go back down and emit the same photon, or it could go down any series of steps (allowed by the spin of the energy level) like 5-3-1 or 5-4-2-1, etc., emitting a series of photons with different wavelengths than the origina... | [
"Yes they can. It's not the only possibility but they definitely can."
] | [
"Thanks for answering :)"
] |
[
"Is it possible to get multiple different colds/flu viruses at the same time? If so, what are the effects?"
] | [
false
] | What are it effects on the body, and how does the body defend itself, would it take longer to fight off? Is it more difficult to fight off different viruses vs just one type? Do the effects compound on top of each other? | [
"Yes, this is called a \"superinfection.\" ",
"The effects will vary quite a bit depending on the details. Many of the responses of the immune system to an infection are general - if you get infected with two rhinoviruses (one of the virus types that causes \"colds\") of the same type or two rhinoviruses of diffe... | [
"A fungal infection in the skin is not likely to effect the immune response in, say the lung. Again, it depends a lot on specifics, and some infections can have systemic consequences, but as I said before, it's hard to run out of immune response. The reason that having two different kinds of infections in the lungs... | [
"Would having a fungal infection of say... of the skin decrease the effectiveness of the immune systems ability to fight a bacterial and or viral infection at the same time?"
] |
[
"Would an obese person, provided with enough water and nutrients, become completely skinny before starving to death?"
] | [
false
] | null | [
"This has actually been done... year without food:",
"http://pmj.bmj.com/content/49/569/203.abstract",
"Doesn't eat for over a year, poops every 42 days and lost 275 pounds. "
] | [
"Rather than nutrients, I think he was reaching for trace elements in the diet like \"vitamins and minerals\" --i.e. if an obese person was surviving on a diet of water and diet supplements, would they lose all their fat before starving to death? Or, would the lack of proteins and readily convertible carbohydrates... | [
"The paper (without a paywall) can be found ",
"here"
] |
[
"Would it be possible to use GFP to create glow in the dark tattoo ink?"
] | [
false
] | [deleted] | [
"Not \"glow in the dark\" but fluorescent (i.e. visible under UV (black) light), yes, absolutely. You'd need to use a virus to transfect your cells. If you just injected GFP your body would break it down.",
"There are rumors everywhere about scientists who accidentally injected themselves with GFP transfecting v... | [
"Not \"glow in the dark\" but fluorescent ",
"For true \"glow in the dark\" you would need all of the enzymes that make ",
"luciferin",
" plus the lusiferinase enzyme."
] | [
"Splicing the gene that codes for GFP into skin cells might work, but there would be a risk of dermatitis if your immune system attacks the foreign protein."
] |
[
"Why is it that we start to forget a dream soon after we wake up? Why don't we remember them like everything else?"
] | [
false
] | null | [
"The more impressive your dream or thought, the more likely you are to remember it.",
"Quoted from ",
"this",
" article"
] | [
"Would it be possible to \"introduce\" the norepinephrine hormone while someone is dreaming to allow them to remember their night of dreams as clearly as if they were recalling the previous day's events?"
] | [
"I've currently quit smoking and I wear the nicotine patch when I dream. My dream recall has never been better in my life, and I surmise that the cause is increased norepinephrin in my brain while I'm asleep, a reason that nicotine is addictive. Norepinephrin belongs to a group of chemicals called the catecholamine... |
[
"How come a solar eclipse could blind you?"
] | [
false
] | null | [
"Looking at the sun will blind you. Any time, anywhere. Including when you look at the sun during the partial phases of a solar eclipse. Naturally, people who don't know any better are more likely to look at the sun during a solar eclipse. They should not. One can look at the sun safely only during \"totality,\" th... | [
"Because the sun is really bright, so bright in fact that you cannot focus your eyes on it. However, during an eclipse, it's much easier to focus on the sun, because the moon is dimming some of the light, but since the sun is just as bright as before, if you focus your eyes up there, it'll ruin your eyes, just as i... | [
"TL;DR: ",
"Eclipse Eye Safety",
"It can blind you if you try to observe any partial stage of the eclipse through ",
" Not all dark filters are equivalent. ",
"Even if a filter blocks enough ",
" light to allow observation, it may still be allowing a dangerous amount of UV and IR light to painlessly ent... |
[
"What is the highest number of beats per minute that the human ear can discern?"
] | [
false
] | How many beats can the human ear discern before it just sounds like one, continuous note/sound. And is it different for different sources of sound? | [
"Not a scientist, but a musician. 20Hz is about the lowest tone most people perceive as a, well, tone. Lower than that and you hear the individual cycles as beats (or you hear nothing at all). Similarly, if you take a percussive beat and play more than about 20/second, it will transform from a beat pattern into a ... | [
"Our ears have three bones call the ",
" (latin for hammer), ",
" (anvil), and ",
" (stirrup) connected to the tympanic membrane, the outermost source of detection of longitudinal waves in air pressure that we know as sound.",
"The vibrations are transferred from the membrane to each of the three bones in t... | [
"Lower than that and you hear the individual cycles as beats ",
"Just to clarify, this would be 1200BPM."
] |
[
"Could a power generator in geostationary orbit transfer power to us via wire?"
] | [
false
] | Some context, when I was way younger in a physics class we were discussing having a nuclear reactor in orbit and the advantages and disadvantages, when posed the question of how we'd get the power down to earth and I suggest, well, a wire. Now everyone looks at me like I'm a moron, I know the 'correct' answer was to be... | [
"In theory it would work. In practise we don't have any materials that are strong enough to make the wire. It would also be incredibly expensive...enough that a wireless solution would be far better even if constructing the wire was feasible."
] | [
"It's called a ",
"space elevator",
". Basically the only thing preventing us from building it is having a light and strong enough material for the wire."
] | [
"Huh, I'd heard of space elevators but had always thought them a silly idea due to bad explanation, plus the name is a bit iffy. I had always thought it would just be a huge tower with all the support coming from the base.",
"This is exactly what I was thinking of, thank you."
] |
[
"As our solar system/galaxy moves is it possible that time could slow or speed up depending on our position?"
] | [
false
] | [deleted] | [
"Stars are sufficiently spaced apart that as we orbit around the centre of the galaxy we never really get close to anything else. We basically just feel the average gravitational field for this radius. Our orbit is not perfectly circular, but that's a fairly small effect. If you're looking at time dilation, the big... | [
"Time dilation only really has a measurable effect in extremely strong gravitational fields and at extremely high speeds. These aren't common.",
"Also, stellar mass black holes (i.e. black holes that formed from dead stars) don't actually have exceptional gravity! Gravity basically only depends on mass, and a bla... | [
"Time dilation only really has a measurable effect in extremely strong gravitational fields and at extremely high speeds. These aren't common.",
"Also, stellar mass black holes (i.e. black holes that formed from dead stars) don't actually have exceptional gravity! Gravity basically only depends on mass, and a bla... |
[
"With all the covid tests going on are we getting any non-covid related data from the tests?"
] | [
false
] | I would imagine all personally identifiable information(PII) would be stripped, but this would be a huge waste of an opportunity to do some other research if we didn't collect the data. | [
"Probably not exactly what you’re looking for but I know a study was done to determine if maternal covid during pregnancy impacted long term infant development. There was no measurable difference between babies born to mothers who had covid during pregnancy compared to those who didn’t. However, instead what they f... | [
"Or I also read, could be contributed to baby's lack of early socialization."
] | [
"If the organization doing the testing got permission (written, explicit) regarding how information was to be used, things like age, race, employment, etc could be used for a study.",
"Given the small quantities of sample -- most places don't use the same sample for PCR and Antigen -- any other testing and result... |
[
"Why does metal have a smell?"
] | [
false
] | null | [
"If you're referring to the metallic smell that is frequently associated with coins, it is actually the oxidation of oils and other components found on your skin that transfers to the metal. The metal acts as a catalyst in the oxidation of these components.",
"An experiment you can try yourself is to wash a bunch... | [
"THANK YOU! this solves a 40+ year old puzzle."
] | [
"You're not smelling an engineering metal; they aren't volatile enough (meaning that they don't evaporate quickly enough) for there to be available molecules to interact with your olfactory system. However, you may be smelling a relatively volatile material coating the metal or produced by a chemical reaction with ... |
[
"Why are there two bones in your lower leg and only one in you upper leg?"
] | [
false
] | [deleted] | [
"Well the lower leg has a different function then the upper leg. While both are supporting your weight, the lower leg also is in control of your foot. By having two bones, it allows you to \"roll\" your foot. This can be seen also on your arm. The forearm is made up of two bones which allows you to move your wrist ... | [
"They both have a wide range of motion (due to the ball and socket joints) but they can't rotate like the lower limbs. For example, if you keep your bicep still, you can turn your forearm so that you can see the top an bottom of your wrist. You cannot do that same motion to your upper arm especially when you keep y... | [
"It adds a whole new degree of freedom to the system. A degree of freedom is basically a definition of how many directions something can move in space. They are in layman's terms, up-down, left-right, forward-backward, and a rotational direction around each of those three axes, for a maximum total of 6 degrees of f... |
[
"Does the post-1945 increase in background radiation have any effect on our health?"
] | [
false
] | From what I understand, after 1945, because of the nuclear tests, the background radiation has increased in a significant enough amount to contaminate steel production noticeably. Does this increase affect human life and health? | [
"Luckily the numbers of background radiation are really low. I wouldn't mind if it were, say, doubled. IIRC a dose of 500 mSv is correlated to a 3% risk. Background radiation is merely 3-6 mSv per year."
] | [
"after 1945, because of the nuclear tests, the background radiation has increased in a significant enough amount to contaminate steel production noticeably.",
"You have a source for this? How much (numbers) has it increased?",
"Anyway, assuming the above is correct, for stochastic health effects at least accord... | [
"You get ",
" more radiation put through your body every time you fly in a 737. It's certainly not enough to worry about."
] |
[
"Is watching a bright screen (computer/TV) in the dark damaging to your eyes?"
] | [
false
] | By in the dark, I mean without any lights in the background. If it's damaging, why is that? | [
"Reddit has a pretty mediocre search function so don't feel too bad."
] | [
"This question has been asked several times before. You may be interested in the following responses:",
"http://www.reddit.com/r/askscience/comments/1gijxx/has_there_been_any_observed_damage_to_the_eyes/",
"http://www.reddit.com/r/askscience/comments/z6qh4/is_sitting_in_front_of_a_computer_staring_at_the/",
"... | [
"I tried searching, apparently not hard enough. Thank you very much, I'll mark this as answered.",
"Edit: Apparently I cannot mark it as answered, too bad."
] |
[
"What is the tensile strength of human ligaments? Is it constant? If not, can they be strengthened by working out?"
] | [
false
] | null | [
"resistance training can increase the cross sectional area and tensile strength at the insertion site of human tendons and ligaments",
"http://www.rehab.research.va.gov/jour/00/37/2/wren2.html",
"http://www.rehab.research.va.gov/jour/00/37/2/wren2.html"
] | [
"this is actually a link to a theoretical model of how tendons/ligaments may adapt to a stimulus (ie resistance training), but it is based on animal models where the exercise loading was not described very well. ",
"This to me is not very high quality evidence that resistance training does provide actual increas... | [
"I feel I might have a unique perspective on this question. The tensile strength of human ligaments varies widely depending on the ligament in question. This is due to the different composition of ligaments in the body. ",
"There are some interesting factors to consider when discussing ligament strength. For exam... |
[
"I recently learned that some insects release a pheremone when they're killed that attracts other insects to their corpse. What is the reason for this? Wouldn't it make more sense to release a chemical than warns of danger?"
] | [
false
] | [deleted] | [
"Ants for example have a graveyard where all the dead ants go. When an ant dies, it releases a pheromone which attracts other ants, who bring the dead ant to the graveyard. I assume having all dead ants, some of them probably dangerous because of infectious diseases, in one place that the ants never visit except to... | [
"On a side note this is an interesting undertaking by using oleic acid on a live ant and observing surrounding ants take him to the ‘graveyard’ while still alive. ",
"https://youtu.be/ZPw9dSV6y2c"
] | [
"https://phys.org/news/2015-12-arms-social-wasps-alarm-pheromones.html",
"In the case of wasps, if one wasp has been killed the killer may well pose a risk to the whole hive. It's to the hive's advantage to be proactively defensive, and the pheromone marks the potential enemy - rather in the way explosive dye cap... |
[
"Why is it that when propellers reach a certain speed they seem to slow down?"
] | [
false
] | I've seen this phenomenon plenty of times. is a great example. You can clearly see the propeller speeding up, but once it gets fast enough, it seems almost stationary, or that it slows down tremendously. Why is this? | [
"Ahhh this is a funny phenomenon. It has to do with aliasing.",
"Aliasing is an effect of sampled signals.\nYou know that a camera takes shots every few milliseconds right?\nWhat happens is that we piece together the frames you get a smooth film. But with symmetric objects we get a special effect.",
"Imagine a ... | [
"...what about with the human eye? It's not just cameras that this effect appears."
] | [
"Hm to be very fair, I thought its not relevant for human sight, when we cannot capture it it blurs for us, but we never suffer the image by image effect as eyes send a continuous signal to the brain."
] |
[
"Is there a theoretical maximum resolution of a digital image made from scanned film? What determines this?"
] | [
false
] | Obviously there are constraints with currently available hardware and cpu power, but does film itself have infinite resolution? | [
"It depends how big the film is, and how fine the crystals in the film grain are. It's also apples and oranges.",
"Film is made up of tons of tiny, light-sensitive particles. Different types of film have very differently sized particles. The smaller they are, the more detail they can capture (but also, the less s... | [
"The light sensitive particles in film are known as grain, and they have a specific physical size. ",
"There is generally a relationship between the size of the grain particles and the sensitivity of the film; film with bigger grain is more sensitive but has less resolution. ",
"Very roughly, 35mm film is aroun... | [
"The light sensitive particles in film are known as grain",
"Note: the size of the clumpy spots visible in film (grain) is ",
"significantly larger than the actual light-sensitive particles",
". Because the light sensitive particles are randomly distributed, and the human visual system tries to extract meani... |
[
"Was my physics teacher right about soda gas behavior?"
] | [
false
] | [deleted] | [
"Yep. What matters is the volume of air relative to the volume of liquid.",
"The way a coke \"goes flat\" is this: Carbon dioxide is a ",
" gas - it dissolves in liquid - and there is dissolved carbon dioxide gas in the soda. That's what makes it fizzy. Molecules of a soluble gas, when dissolved in a liquid, ar... | [
"Ergo, lessen the volume of space that the gas has to fill up to get to this point, and you lessen the amount of co2 that ends up leaving the liquid. So, press in the sides to lessen the volume. If you squeeze it all the way until the coke is all the way to the top, and put the cap on, no co2 will leave the liquid.... | [
"I've been dying to ask a similar question, especially because (if you've ever tried this), the soda will often \"re-inflate\" the 2-liter bottle which I assume will mean that there are ",
" carbonation losses than if that space had been filled with some room air to begin with.",
"I don't have an answer for you... |
[
"How has light had time to reach us from distant stellar phenomena?"
] | [
false
] | More precisely what I mean is, if our universe is only 13-14 billion years old, how has light from objects that are 40 billion light years away reached us. I understand that expansion got them so far out but I don't understand how the light has reached us in a fraction of the time it should take: it should take 40 bill... | [
"More precisely what I mean is, if our universe is only 13-14 billion years old, how has light from objects that are 40 billion light years away reached us.",
"The objects were much, much closer when they emitted the light. Over time, the distance between us and the light and the distance between us and the objec... | [
"Roughly, you look at the rate at which distant objects are receding, note how that recession speed depends on distance, and then calculate how far into the past you would have to go for all of those distant objects to be located here. To do this properly, you use the mathematical machinery of the general theory of... | [
"Hold on, if the star was 13 billion light years away when it produced the light",
"I didn't say it was 13 billion light-years away when it produced the light; I said it was much, much closer than it is now. In fact, making some reasonable assumptions and using the current best fit data, if we're currently receiv... |
[
"Does cold weather lower your immune system's capability to defend against disease?"
] | [
false
] | I know that colds are not caused by a drop in temperature, but someone once told me that one reason colds are more common in the winter is that your immune system weakens from the cold, and therefore you are more likely to get a disease. | [
"Unless you become pathologically cold (hypothermia), the cold does not affect your immune system. There are many reasons as to why we seem to become sick more often when it's cold. We tend to confine ourselves to smaller, enclosed spaces, surrounding ourselves with people who are potential carriers of disease. ... | [
"Does humidity matter as well as heat? I've heard that cold/flu viruses survive longer in cooler, drier environments."
] | [
"Not sure about humidity, but temperature does matter. Rhinovirus (the virus that causes about half of all colds) proliferates at about 90 degrees F, not your body's internal temperature of 98.6 degrees. This is why it attacks the upper respiratory tract (nose, mouth, throat), which is much cooler than the rest of ... |
[
"How do I calculate the \"heat transfer\" function for a tank of gas?"
] | [
false
] | I have some sensors installed on a carbonation system that's installed in a remote location, effectively outside. Specifically, we'd like to be able to estimate the amount of gas remaining and track usage in the tank. The tank in question is what I would call a 280 of CO2: the tank holds about 280 cubic feet at atmo... | [
"ChemE here. In those conditions the CO2 is in a mix of liquid and gas, the vapour pressure of the liquid depends on the temperature. Therefore, you can't really use the pressure to know the %fill of the tank since as long as the tank contains liquid CO2 the pressure depends only on temperature, and when the tank d... | [
"A CO2 'gas' cylinder contains both liquid and gas phases. The liquid occupies the bottom of the internal volume and it slowly decreases as the gas is removed from the top. This happens in order to maintain a constant vapor pressure when the two phases are in equilibrium. Once there is no longer enough moles in the... | [
"But what you're saying is that I'm going to see relatively flat pressure (if I compensate for temperature), and then a rapid drop off once the liquid is gone?",
"Yep. You don't need statistical analysis to compensate for temperature. The pressure will be at the saturation pressure for CO2. ",
"https://www.ohio... |
[
"How can you possibly see an object freeze in time as the object crosses the event horizon of a black hole?"
] | [
false
] | [deleted] | [
"Imagine you're sending a probe into a black hole. And its a super super simple probe to test for just this idea. It's a very bright lightbulb on a blinking circuit. It blinks 100 Hz, eg. As it falls closer and closer to the black hole, you find that the rate of blinking slows to 1 Hz, then to .01 Hz and so forth. ... | [
"my understanding was that, for an outside observer, objects falling into a black hole never crossed the event horizon, like an asymptote (I'm proud to have remembered this word) "
] | [
"Oh. I don't recall that exactly, but I think the Schwarzschild metric dt",
" term seems to imply it goes like 1-1/r where r is the distance to the center of the mass. So I'd say it's more like exponential, where there's a divergence at the event horizon where the dilation goes ",
" infinity."
] |
[
"If a person gains weight gradually, will their leg muscles (quadriceps, hamstrings, calves etc) grow proportionally to support the added weight?"
] | [
false
] | I expect that they will grow as the increasing weight simulates a slim person doing leg workouts with gradually increasing weights. | [
"They would have to, otherwise you wouldn't be able to walk. On the other hand, it depends on what kind of weight you are gaining. Obviously gaining muscle mass will cause your muscles to grow. On the other hand, gaining a lot of weight in the form of fat has other consequences. The fat gets deposited all over the ... | [
"If say you're a semi fit person wise average weight. Maybe 6' tall and 190lbs and you gain 110lbs to be 300 lbs. Stay at that weight for maybe a year. Then lose all of the fat weight you gained. Would you be stronger than before gaining all the weight"
] | [
"Still no. The same hormones that are active when you burn fat also promote the breakdown of muscle. This is why people who do cross fit aren't usually as \"ripped\" as people who focus solely on strength training, although every body is different. From a medical perspective, doing something like this intentionally... |
[
"A chicken egg is 40% calcium. How do chickens source enough calcium to make 1-2 eggs per day?"
] | [
false
] | edit- There are differing answers down below, so be careful what info you walk away with. One user down there in tangle pointed out that, for whatever reason, there is massive amounts of misinformation floating around about chickens. Who knew? | [
"Chickens are omnivores, but free-range chickens eat a great many insects, and insect exoskeletons are similarly rich in calcium. They'll also eat just about anything else, including small mice, voles, moles, lizards, etc., bones and all.",
"In a commercial setting, they are supplemented with oyster shells, or w... | [
"Home chicken keepers sometimes feed old eggshells back to their chickens.",
"Yes, but you have to be careful to mash up the eggshells small enough so that the chickens don't recognize them as eggshells, or else they'll start to eat their own eggs after they lay them."
] | [
"Chickens will also eat their own eggs if the chicken is deficient in calcium."
] |
[
"Even though Jurrasic Park is fictional, is the science possible to make extinct animals alive once again using extremely old DNA?"
] | [
false
] | How would it work? Does DNA go bad? What would be the errors in creating extinct animals? | [
"The half-life of DNA is such that you'd never get a decent enough sample of a dinosaur to clone it. A mammoth though? Sure.",
"Assuming we did, by sheer dumb luck, somehow find a dinosaur so well-preserved that we could somehow extract a complete enough genome to use to clone the animal though, a new set of prob... | [
"SMURG is right, I'd just like to drop an expansion onto his comment.",
"Cloning is hard. To get a clone to survive takes a lot of work, a lot of genetics, and a lot of luck.",
"Take a look at the Pyrenean ibex, the first animal to become extinct and then ",
". An Pyrenean ibex is an ungulate (hooved animal) ... | [
"Which doesn't even touch on whatever gut fauna the creature had which would be completely impossible to reproduce."
] |
[
"What are the effects of vaccine mandates on vaccination rates?"
] | [
false
] | In King County, WA USA there appears to be no effect as vaccination rates are relatively unchanged since the August 9th mandate announcement by the Governor and County Executive. August 9th Announcement: Vaccinations in King County by date: | [
"They were talking about this on CBC radio here in Canada the other week. They said basically, people who aren't vaxxed fall into a couple of groups. Those that intend to get it at some point but are really in no rush, people who rather indifferent to getting it or not, people who are hesitant (sometimes with langu... | [
"Small percentage wise, yet inordinate amount of attention given to these people by the media"
] | [
"If you are talking about COVID specifically - This may affect some sub populations more than others.",
"It is also hard to dissociate the FDA approval , and fear of variants (and other factors) from mandates as many of them came at near the same time. ",
"It is also really too soon to evaluate - many of the ... |
[
"Why is random dispersal of matter more energetically favorable than if matter is clumped in one spot (question of entropy)?"
] | [
false
] | Disclaimer: I'm a biology major, not a physicist. I am going back over osmosis/passive diffusion and Gibb's free energy, and I don't understand why the same amount of matter (therefore, same energy) is more favorable in one configuration (random/dispersed) versus another (clumped or all on one side). | [
"They have the same energy (barring some sort of interaction potential) but there are many more ways for particles to be randomly dispersed than clumped together, so if the particles are found in any equally-likely configuration, there is a high chance that that configuration is random-looking."
] | [
"Find this a very good short written explanation. The answer is similar to saying that: How is it more favorable for a 1000 dice to have every number of eyes come up a roughly equal amount of time. "
] | [
"So instead of thinking of it as an energetically more favorable state, is it more correct to say that it's more probable for particles to arrange randomly (because there's more ways for them to be randomly arranged) than clumped in one spot (only so many ways in a finite space that they could arrange in a clumped ... |
[
"How do astronomers determine how far newly or past discovered stars are? Like how do they know one twinkling star is 8ly and another is 150ly?"
] | [
false
] | null | [
"Distance calibrators are a giant topic in astronomy. I'll give you the most simple example that requires only geometry, it's called parallax. You can make a triangle with three points: Sun, Earth and star. If the star is not so far away (or you have a really good/big telescope) you take a picture of the star in Ma... | [
"Wikipedia has a nice description of the different techniques used for different distances.",
"https://en.wikipedia.org/wiki/Cosmic_distance_ladder",
"Out to about 100 light years, an Earth-based telescope can estimate the distance based on how much the stars seem to move when seen from one side of the sun vs. ... | [
"From the angle that you deduce you put one over said angle and you get a big number in parsecs (the reason this works is the angle is usually a decimal) and the you have the distance in parsecs. you can times that number by 3.26 for light years or 1.92*10",
" for miles!"
] |
[
"Do other animals commit suicide, and does it seem like it's ever due to something similar to depression?"
] | [
false
] | null | [
"There are numerous instances of dolphins committing suicide. ",
"The main figure in the movie \"The Cove\" detailed the suicide of dolphins under his watch in captivity. Stranded and stressed dolphins in the wild have also said to have committed suicide. ",
"At work so not many links, but a 1-minute google se... | [
"In China there have been reports of bears who commit suicide or attempt to in order to escape the torture of bile collection. Here's a story of a mother bear who killed her cub to save it from a life of pain and torture:",
"http://ingenira.hubpages.com/hub/A-Teary-Mother-Bear-Killed-Her-Baby-and-Committed-Suici... | [
"That just breaks my heart."
] |
[
"Is there anything (Natural substance, man-made medicine, specific injury, etc.) which can completely negate all pain?"
] | [
false
] | I tried googling this, rephrasing it multiple times, but it turned up nothing. Does anyone here at know the answer? | [
"You've clearly never been ",
"anesthetized",
"."
] | [
"Any spinal cord injury that affects your ",
"spinothalamic tract",
" is going to completely sever the neurons that are sending pain up to your brain. Brainstem lesions along that tract or the ",
"trigeminothalamic tract",
", which is the same thing but for pain from your face, will cut out pain.",
"Enke... | [
"There are some rare disorders known as ",
"congenital insensitivity to pain",
". People with these do not experience physical pain which typically causes them severe physical injuries from childhood: e.g. burns, lip-biting, walking on a broken limb etc. "
] |
[
"Can you tell me what dangerous animals are in Jamaica?"
] | [
false
] | I know, for example, Hawaii has giant centipedes, which are poisonous. I'm curious which animals and insects are in Jamaica which are dangerous/venomous. Water creatures count too. | [
"Picking the low hanging fruit here, but ",
" are extremely dangerous. Seriously. Most of them are fine and wont bother you if left unprovoked, but a small percentage are very aggressive."
] | [
"Mosquitos. Sharks. Jamaican Boa. "
] | [
"Jamaican boas only seem to get to 6ft; that really isn't big enough to fuck your shit up. It'll be able to give you a nasty nip, sure (what animal can't?), but for a constrictor to actively endanger the life of a grown person you're looking at it being 9ft and upwards."
] |
[
"What do babies think about?"
] | [
false
] | null | [
"is that you speaking as a layman or you speaking with some expertise/knowledge?"
] | [
"is that you speaking as a layman or you speaking with some expertise/knowledge?"
] | [
"I'm assuming he was speaking as a layman? That's disappointing I actually wonder this very often."
] |
[
"Can plants get cancer from the sun like humans can get skin cancer?"
] | [
false
] | null | [
"Skin cancer is cause by damage to to our DNA by UV light, usually the UV light creates cross-links between the base pairs. Plants have a really cool enzyme called photolyase, which is light powered enzyme that breaks these cross-links and repairs the DNA. "
] | [
"For that reason, cancers tend to occur on the trunk. Since that is less exposed to sunlight due to the thick bark layer, it is possible that rates of sun-induced cancer in plants are pretty low, even if it is theoretically possible.",
"This is mostly guesswork though, since there's no empirical backing here."
] | [
"For that reason, cancers tend to occur on the trunk. Since that is less exposed to sunlight due to the thick bark layer, it is possible that rates of sun-induced cancer in plants are pretty low, even if it is theoretically possible.",
"This is mostly guesswork though, since there's no empirical backing here."
] |
[
"Does infection produce different kinds of antibodies than vaccination?"
] | [
false
] | I know that for example Hepatitis B vaccination produces different antibodies than infection. This is because the vaccine does not contain certain structural components of the virus. Does something similar happen with SARS-CoV-2 as far as we know? | [
"For the current vaccines for Covid-19 in the US (Pfizer, Moderna, JJ) they’re expressing only the spike protein. There are plenty of other protein epitopes you could generate antibodies to via an actual Covid-19 infection.",
"In fact, this rapid antigen test uses both spike and nucleocapsid protein to look for a... | [
"Your body is constantly refining the antibody response, keeping the B cells that make the highest affinity ones."
] | [
"Upon infection, does the body just allow any antibody to be generated and keeps around all of them? Or is there some sort of logic in there or possibly selection"
] |
[
"If we flip flop between glacial periods and non- glacial periods (ice ages) why then is global warming considered so dire? Wouldn't it mitigate the severity of the next ice age?"
] | [
false
] | I have been reading a lot about ice ages recently and the different hypothesis to what causes them, the massive ice sheets covering North America (2miles thick) and how devastating an Ice age would be to human population and civilisation. Also during history when the planet warmed humans done really well. I know C02 is... | [
"Portions of my answers below are borrowed from an answer I wrote to another, semi-related question.",
"Are humans this time solely responsible for this ice age ending?",
"Technically we are still in an ",
"ice age",
", and what we're talking about is the transition from glacial to interglacial periods with... | [
"Thank you greatly for the in depth and easy to understand response, you have definitely enlightened me and have put to bed my pessimism, on of how much humans are making an impact. I work in a dirty fossil fuel industry and my guilt has me researching if it is all really as bad as scientists say, I am convinced th... | [
"The fossil fuel industry has deliberately tried to muddy the waters, so it makes sense that people are confused. See: ",
"https://exxonknew.org/timeline/"
] |
[
"When spacecrafts need to change to a higher orbit, do they burn sideways or downwards?"
] | [
false
] | Both make sense in my head - burning sideways (rocket exhaust pointing away from where you're going) seems like it should work, by enlarging your orbit. But then I thought about how your velocity is lower when you're in a higher orbit. So if I burn sideways, would my orbital height increase while my speed decreases? Ca... | [
"Well, the thing to keep in mind is that when you're orbiting you're not floating around the earth, you're hurtling around it at high speed. So, let's say you're orbiting towards the earth and point your thrusters downward. You'd gain a little vertical velocity, but in order to get into a higher, circular orbital p... | [
"Strictly speaking, the correct answer is \"yes and yes.\"",
"Either one will accelerate you to a higher orbit. However, \"buring sideways\" is the method used in a ",
"Hohmann Transfer Orbit",
", which is the most fuel-efficient way to enter a higher orbit. It works like this:",
"Assume you start in a ci... | [
"The bi-elliptic transfer is more efficient because of the ",
"Oberth effect",
". Burning at higher velocities is more efficient than lower velocities, so if you're making a ",
" change in orbit, a bi-elliptic transfer biases the burns to be done at higher velocities: a big burn at high velocity, a smaller on... |
[
"Askscientists- show us your favorite figure!"
] | [
false
] | Science is all about communicating and a picture is worth a thousand words- at least. Share with us your favorite figure or graph from a scientific paper. Ideally it should be self-explanatory, but it might be helpful if you informed us why it is so important or interesting to you or your field. Please link to the actu... | [
"This is almost as hard to answer as \"what's your favourite science fact\" but right now I'll go with the ",
"decay of the Hulse-Taylor binary system",
" because it's so cool.",
"What you're seeing is the orbit of two pulsars slowly decaying because they're emitting gravitational radiation."
] | [
"ive always liked ",
"this",
" cardiac physiology graph.",
"It contains more information about how your heart works and the actual mechanics and pressures than dozens of pages. It makes it easy to understand murmurs, reflux, back flows and abnormal pressure changes, and allows you to predict the signs and sy... | [
"Ah I love that one too- I once saw a couple of lectures by a cardiac tissue engineering guy who had an animated version of that figure, scanning from left to right. It made everything so much more clear than anything else he had said in the 20 minutes previously. "
] |
[
"Why is it critical to have extremely accurate time, for Electricity distribution networks to function?"
] | [
false
] | I over heard a couple of Engineers at an Electrical power plant discuss the importance of having extremely accurate time through atomic clocks (something like 1 second of error over 3,000 years is minimum acceptable). Hoping some one could explain, exactly why such time accuracy is required, what does it enable? | [
"Well, strictly speaking your premise is false: large-scale electrical grids have been around long before atomic clocks. So the pedantic answer is \"it's not necessary\".",
"When multiple generators are connected to the same power line, their phases have to be carefully matched. In a typical AC generator, the osc... | [
"You can watch the US grid frequency changes as the loads are shared.",
"http://fnetpublic.utk.edu/frequencymap.html"
] | [
"/u/teraflop",
" gets the facts right - AC power grids do not need atomic clocks to operate. Grids involving multiple generators (power plants) must only be synchronous, meaning that they operate at the same AC frequency, nominally 60 Hz, or 60 cycles per second. Synchronization can be achieved using analog dev... |
[
"How are air pockets formed?"
] | [
false
] | So, my sister asked me to explain this, but I found that I can't. How are air pockets created, by air pockets I mean the air that is trapped when say, a cave fills with water, but raised areas in the ceiling retain air. The example that brought it up is from the original Pirates of The Caribbean when Will and Capt. Jac... | [
"The canoe in PotC was presumably pulled down from the surface and the air doesn't escape because the canoe is fairly airtight, and because for the air to go down around the hull it would have to lift water (which requires energy) so it stays where it is. ",
"The canoe scene is completely impossible in real life ... | [
"Ok, thanks for the explanation."
] | [
"Also, an extremely generous calculation based on the size of the boat says there's only about 5 minutes worth of air in that thing, even if the two were at rest. There's no way they could breath for the time it takes them to walk that distance, even if they were exerting no effort."
] |
[
"Why does isometric transition only occur with gamma rays?"
] | [
false
] | Question about gamma decay. Is there any reason why when a radioactive isotope in an excited state emits gamma radiation over x-rays? I understand that gamma decay is the fastest way to get rid of the excess energy but is it possible that if an excited nucleus didn't have enough energy to emit gamma rays that it would ... | [
"Not if they had the same energy. The photon retains no memory of where it came from."
] | [
"There are some circles in which \"gamma rays\" refer to higher-energy photons than \"x-rays\", but despite often being taught in high school, this is not actually the usual terminology.",
"In astrophysics we make a distinction. There are x-ray experiments and gamma-ray experiments based on how energetic the pho... | [
"if you had a gamma ray photon and an x-ray proton could you tell which is which, without knowing their origin? "
] |
[
"If beef is properly prepared, wouldn't that practically eliminate the risk of e coli causing foodbourne illness?"
] | [
false
] | This question mainly comes from the massive recall of beef products in Canada. If beef is cooked to an internal temperature of over 160 degrees Fahrenheit, wouldn't that kill off the bacteria? Is this meat too tainted to eat even after thorough cooking? | [
"I thought this was true. In, theory of the meat is cut properly then searing the outside alone is good enough because there is no opportunity for bacteria like ecoli to get inside. Ground meat is a problem because the outside and inside get mixed up...",
"Apparently (at least here in Canada) Costco has been stab... | [
"Its safe to eat many raw meats, provided you kill surface contaminants, or eat it right off a fresh kill. Beef especially, but even pork is processed in such a way that its misconception or paranoia that leads people to believe parasites are still a problem. Trichinosis was just about eliminated in the 60s and has... | [
"Yes, it would kill off the bacteria. Though, there are certain products or chemicals of bacterial metabolism that can still make you sick, and those don't go away with heat."
] |
[
"How is the force on light particles conceptualized?"
] | [
false
] | If the characteristic equation for Force is , and photons have no mass, how is it that we can conceptualize a photon's interaction with other particles? Do we use the observed change in momentum of the massive particle and then deduce what kind of force was exerted by the photon retroactively? Or is there some formula... | [
"F = ma is a simplification/special case of a Newtonian principle that only applies to certain classical systems.",
"First, Newton's second law is actually that F = dp/dt, which is to say that the force applied to an object is equal to the rate at which its ",
" (represented by p) changes. If you have an object... | [
"I should also say that, at least in my experience, most people who do work in classical mechanics don't use Newton's formulation either. They tend to use ",
"Lagrangian",
" or, more often, ",
"Hamiltonian",
" formulations."
] | [
"Ah, okay that answers my question pretty well. Thanks!"
] |
[
"Why does wind whistle when it blows through objects like doors, trees etc?"
] | [
false
] | null | [
"Wind howls when it’s broken up from passing through or around objects, such as trees. The gust of air will split up to move around the tree and then comes back together on the other side. Due to factors such as the surface of the tree and the air speed, one side of the wind is going to be stronger than the other w... | [
"This also explains why wind whistling and howling tends to be much more pronounced during the winter months. Without leaves to catch the wind, all those branches will have a lot more turbulent air rushing around and past them."
] | [
"It's due to a concept known as ",
"vortex shedding",
". In short, it's a fluid dynamics effect that can happen within a range of Reynolds numbers when a viscous fluid flows around a disturbance. The sound you hear is related to the frequency of the vortices being shed. ",
" (partially true). You can see slow... |
[
"Why are we discouraged from giving suspected shock victims water to drink? And why are they thirsty?"
] | [
false
] | Please be specific. I am studying for my Nursing registration exam (in Canada), and have come across this bit of advice annually in first aid recertification and often in reference to emergency nursing care. I want specific rationale. As in, microbio/biochemistry/cellular biology level explanation. Go deep, Reddit. I'l... | [
"Shock is a hypotensive/hypoperfusion state, depending on the exact cause of shock, they will need specific treatment. ",
"Being hypotensive the body is going to draw fluid into the vasculature from the third space, and the cells, to attempt to maintain BP, and then it's going to start shutting down peripheral v... | [
"1",
"\n",
"2",
"Any good first aid course nowadays should tell you not to give anything to anyone injured by mouth, it's just a terrible idea period."
] | [
"The decreased blood flow to the stomach makes emesis more likely. Filling it while it's non-motile makes this risk increase.",
"If you dump their acids, you're likely to cause hypokalemia as well (remember your pathways here) and then some arrythmia's (do you know which?)"
] |
[
"What kind of damage would a collapsing space elevator do to earth?"
] | [
false
] | In a few anime a falling space elevator has a potential to destroy the planet but what kind of damage would it really do if the elevator was 60,000 miles high? | [
"A space elevator consists of three parts: the terminus up at geosynchronous orbit (or a little higher), the car that moves up and down, and the cable.",
"The terminus wouldn't fall. It's essentially just like a satellite that orbits freely. ",
"The car that moves up and down would most likely mostly disintegra... | [
"To clarify the danger from the cable: it would be moving far more slowly than a meteorite, have a far higher surface area to volume ratio, and presumably not be very dense. We don't have materials strong enough to make a space elevator cable, but the question would be 'would most of the cable burn up before it eve... | [
"The usual material of choice for the cable when discussing space elevators is carbon nano tubes, and they have very high heat resistance. So a cable made of that material would likely make it to the ground."
] |
[
"If we ever build a space elevator, would I be able to climb into orbit without making escape velocity?"
] | [
false
] | This has been bugging me for a while. Pretend we built a space elevator. Pretend there is a ladder on the side in case of emergencies. Pretend I am in good shape and want to climb the ladder cause it'd be a hootenanny of a good time. I know the shuttle needed something like 26kmph to reach escape velocity to leave the ... | [
"For starters, you'd have to climb 22,000 miles to achieve orbital velocity (this is the altitude of geostationary earth orbit). Jump off any lower and you ",
" fall back to earth.",
"The earth is spinning and the space elevator with it. As you climb the ladder, you get further from the center of the earth so... | [
"The idea that you need escape velocity to enter orbit is a common misconception. Even without a space elevator, you can enter orbit (and in fact get arbitrarily far from Earth) at any speed you choose. Escape velocity is the speed necessary to avoid ever being totally stopped by the gravity of a body ",
" throug... | [
"Orbital mechanics are counter-intuitive and fun to learn.\nIf you are into video games I suggest go grab:",
"https://kerbalspaceprogram.com/",
" a great fun, toy like \"space-sim\". Subreddit: ",
"/r/KerbalSpaceProgram",
"http://orbit.medphys.ucl.ac.uk/",
" \"orbiter\" a free and realistic space flight s... |
[
"What happens to a gravitational wave when it crosses a black hole ?"
] | [
false
] | null | [
"Gravity isn't transported by gravitational waves any more than static electrical charge is transported by light. The static forces are from the field itself, which exists both inside and outside the black hole. This is why a black hole can be electrically charged but no light escapes, and why a black hole impact... | [
"The same thing that happens to everything else. It falls into the central singularity.",
"Gravitational waves are impacted by gravity in the same way as all other waves. The difference being that gravitational waves are only impacted by gravity, and nothing else."
] | [
"gravitional waves are basically ",
" in the Gravitational Field (or geometry of spacetime) . The gravitational field of a static black hole is static. It doesn't need any gravitational waves to \"be\". It just \"is\" what it is, based on an equation you can just punch the numbers of the situation into.",
"Whe... |
[
"Do different language make lying easier or harder?"
] | [
false
] | null | [
"Yes and no. Even if you reduce it down to binary signals, one signal could be yes and the other could be no. Sending an incorrect signal for any given situation makes it a lie.",
"In the complexities of human language it is still no different. Giving a false response is always still possible.",
"The degree to ... | [
"That's definitely one aspect of what makes it easier or harder to lie. Another aspect might relate to how sentence structure and conjugation is altered when lying, depending on the kind of lie being told. In English, the difference between \"I did that bad thing\", and \"she did that bad thing\" is relatively easy... | [
"I would personally say this is also a Psychology question. Most \"good\" lying is going to be based on training yourself (or being taught to) hide psychological cues that show you're lying, ie. Looking away, blinking, a twitch, etc. The Language cues that show you're lying are change in voice tone (sudden high voi... |
[
"How do individual cells know what shape to arrange themselves into to form a multicellular organism?"
] | [
false
] | I know that it's "in the DNA", but logistically, how do kidney cells know to arrange themselves into a kidney shape? How do the cells on the outside edge of an organ know to stop expanding outward and changing the organ's shape? Cells can't possibly have spacial awareness, can they? I know there is some rudimentary ... | [
"This a pretty big topic, but I will try to simplify it for you and then you can ask more specific questions.",
"When you think of cell division, you usually think of a parent cell dividing to produce two identical daughter cells. However, during embryonic development, not all cells divide evenly. This is called ... | [
"People like you who take the time to give such a thorough answer just to satisfy someone's curiosity is the reason this is my favorite subreddit."
] | [
"Thanks for that! And I love talking about this stuff anyway :-) It makes me happy when people are curious about biology!"
] |
[
"How does temperature affect London Dispersion Forces?"
] | [
false
] | I don’t how to word it, Im basically asking why do the London dispersion forces occur between two non-polar molecules to form a super cold liquid like liquid nitrogen? | [
"My approach to answering this may not be the direction you were taking this but it is how I think about van der waals forces (London dispersion). I work in a lab that does biomolecular modeling and this force is most often represented by the Lennard-Jones potential. This potential is good at approximating these fo... | [
"This is ultimately a statistical mechanics problem. I would say that how you put it is essentially correct but it would be more accurate to say that it is more probable that atoms are nearer to their contact distance. Once you get to a small enough level everything reduces to statistics and quantum mechanics"
] | [
"This is ultimately a statistical mechanics problem. I would say that how you put it is essentially correct but it would be more accurate to say that it is more probable that atoms are nearer to their contact distance. Once you get to a small enough level everything reduces to statistics and quantum mechanics"
] |
[
"What is the purpose of creating synthetic elements?"
] | [
false
] | Elements such as Californium and Tennessine, what is their purpose? | [
"Most of them are just for research purposes, and no element past Fermium has been synthesized in useful quantities. Pretty much everything past there decays in less than a second.",
"It’s mostly just ",
" but research like this isn’t useless. Far from it. Learning more about the universe is always important, t... | [
"Well californium-252 is a great laboratory fission source. We use it because it produces neutrons. For the superheavies like tennessine and oganesson, we just produce them to learn about nuclear, and possibly atomic physics."
] | [
"It decays some of the time by spontaneous fission, and some number of neutrons are emitted in the process."
] |
[
"How do we know that the climate change we see today is not just part of a natural cycle?"
] | [
false
] | The earth has gone from hot to cold and vice versa without human intervention. How can scientists tell if this isn't just part of a natural cycle? | [
"For one thing, we have ",
"direct evidence",
" that increased CO2 means more radiative heat is trapped in the atmosphere:",
"Both series showed the same trend: atmospheric CO2 emitted an increasing amount of infrared energy, to the tune of 0.2 Watts per square meter per decade. This increase is about ten per... | [
"One example would be that if you look at the charts for frequency of tropical storms, severity of the storms, and quantity of CO2 in the atmosphere, there is a linear increase up until the 1800's when the industrial revolution took place."
] | [
"i wonder the same thing. I strongly suspect that there is no way to distinguish between the natural cycle of ice ages followed by umm, thermal ages(?), and the deviation from that cycle contributed by human activities.",
"An interesting side question tho is, even if we halted/reversed all currently suspected be... |
[
"Physics problem that has been plaguing me since high school."
] | [
false
] | Hypothetical situation. Lets say you have a fighter airplane that flies at a maximum velocity of (just throwing numbers out there) 100 m/s. This plane can fire missiles, which travel at 200m/s. If the plane is flying at 100m/s and fires the missiles, the missiles would travel faster than 200m/s, right? Ok. So what ha... | [
"The question at hand is: What causes the speed limit on the motion of the missiles? Is it air resistance (as is the case for airborne missiles)? ",
"If so, then firing a missile (limited to 200 m/s velocity in air) from a jet (traveling at 500 m/s in air) will cause the missile to fly backward at 300 m/s from ... | [
"Remember that the missile is not travelling at 200m/s relative to the plane as it is released, or it would probably rip a wing off with it!",
"The missile will detach and fire. Its initial speed will be that of the plane, but if it cannot maintain this speed then it will slow down.",
"Obviously in reality miss... | [
"That makes sense, but for a \"practical\" clarification: missiles are generally fairly aerodynamic, which means that the slowdown from jetVelocity+launchVelocity to 200m/s would be pretty slow, so I think you would see the missile speed out ahead of the plane at first, and then gradually the plane would overtake i... |
[
"We're used to burning natural gas in air. What if you reversed things and tried to light a stream of air piped into a natural gas atmosphere?"
] | [
false
] | [deleted] | [
"If the air stream was lit, perhaps from a Bunsen burner, it would appear to burn in the natural gas (mostly methane) atmosphere. But it would be much more difficult to light and maintain a flame, and the flame would have a different appearance...",
"Composition of natural gas: ",
"http://www.beg.utexas.edu/ene... | [
"Please do not do this. But to answer your theoretical question....",
"An air to fuel ratio for Natural Gas of 10:1 seems to be the standard. So for every ten cubic feet of air pumped into the room, 1 cubic foot of gas would be consumed.",
"http://sagemetering.com/combustion-efficiency/air-fuel-ratio-effect-o... | [
"Maybe this doesn't answer your question, but there are industries that use the perfect ratio of pure gas/oxygen to heat industrial processes. I know that glassmaking is one of those. ",
"To try and answer your question, it would explode pretty dramatically, or if you could do the math regarding flame stability... |
[
"How do we know how far light has traveled when it gets to earth?"
] | [
false
] | I suppose this will be an easy one, i searched for an answer here. My question is simply How do we know that the light from the farthest galaxy away is 12.91 billion light years away? What about light lets us say its traveled 12.91 billion years? | [
"Redshift, the wavelengths of light from distant galaxies are shifted to the red end of the spectrum, the amount of redshift is proportional to the distance."
] | [
"A red shift is when an object is moving away relative to the observer. Blue shift is moving towards the observer. ",
"We can use this in a way to measure the distance to stars and objects by looking at emission spectra of the object. For example, a stars emission spectra will have sharp absorption peaks which co... | [
"Thanks for answering. The red blue shift is from the object in question moving towards or away from us correct? Similar to the way we found planets around suns? "
] |
[
"Does the body in any way distinguish between intentionally self-inflicted injuries and other injuries?"
] | [
false
] | Do they heal in the same way in the same amount of time and/or generate the same amount of pain? Or, in the same way that it's nearly impossible to tickle oneself, does the conscious realization of the injury somehow lessen or change the body's reaction to it? | [
"Self inflicted injuries ( and other 'safe' damage) will trigger a flood of endorphins to counteract Your natural adrenalin response. this is why people become addicted to cutting, and similar behaviors."
] | [
"I meant I choose to pinch myself somewhere else on my body with my other arm while I wait for the pins and needles to go away. It explains why that method works at distracting me."
] | [
"During essay exams I bite my left hand really hard when I feel my right starting to cramp."
] |
[
"Can vaccines be inherited?"
] | [
false
] | If lets say the mother ( lets name her Karen) of the child had aquired the MMR vaccine during her childhood, but does not want her child to get vaccinated with the same vaccine as she got, is it possible for the child to have inherited the vaccine or is the only possible way for the child to be protected by having the ... | [
"Short answer - No",
"Long answer - Really, really no. ",
"Vaccines work by producing antibodies in the host which provide protection against pathogens. ",
"There's no gene stuff involved, so this \"protection\" cannot be inherited. ",
"Can this be passed on (mother-baby blood exchange)? - No. "
] | [
"IgG crosses the placenta and IgA is transferred in breast milk. So there is limited protection for a short time. But definitely no true inheritance. "
] | [
"Newborns benefit from acquired maternal immunity. This is a temporary condition that can last from 6 to 18 months after birth and bridges the gap before the babies own immune system becomes strong enough to start fighting a lot of common infections in its own. From this we know that natural immunity is stronger th... |
[
"Why do planets rotate on the same plane?"
] | [
false
] | null | [
"Frequently Asked Questions."
] | [
"Thanks!!!"
] | [
"Why do all planets rotate around the sun on roughly the same plane?",
"They don't. There are variations in the orbits which planets take around the Sun. Most of the 8 planets in our solar system have a small angle of elevation off the plane of the ecliptic. However, the angle is not constant for every planetary ... |
[
"If a certian chemotherapy drug was created that functioned like all chemo drugs (killing dividing cells) to which no cells could develop resistance to, would that effectively cure all cancers?"
] | [
false
] | [deleted] | [
"What you are saying is \"if I magically create a substance that kills cancer and has no side effects, would that cure cancer\". Yes, it would. Also, it's impossible. The whole reason that cancer is hard is that a) what is broken are mechanisms that are essential to normal cell functioning and b) they can be broken... | [
"Not necessarily, there would still be a problem of toxicity, as this wouldn't be specific to the cancer but would also target, skin, intestine, etc. That's also the problem with most chemotherapy treatment, you can increase dosage and kill the cancer but you'd also likely kill the patient."
] | [
"My basic point is that everything is dose dependent, even cyanide or ricin won't kill you with a low enough dose. That's why there's a lot of research into immunotherapy, which should Theoretically decrease toxicity and increase effectiveness. Today's drugs as you say kill the cancer more effectively than normal h... |
[
"Is there a limit to how long a radio wave can be? Would extremely long waves be of any use?"
] | [
false
] | null | [
"Frequencies lower than 1 oscillation within the age of the universe don't produce anything you could call an electromagnetic wave, and similarly wavelengths longer than the Hubble length are not meaningful waves. Apart from that there is no limit, it just gets harder to detect radiation the lower the frequency get... | [
"The longest I've heard of is ELF, used to communicate with subsurface submarines. The extremely low frequency, 76 Hz, allows the signal to penetrate hundreds of metres of seawater, which as a conductor shields against most higher frequency radiation. However, this comes at the cost of terrible bandwidth, a few cha... | [
"Your home wiring is broadcasting EM waves at 50 or 60Hz depending on where you live. In fact guitar pickups are basically antennas and can pick it up. "
] |
[
"Why are some units measured with negative powers?"
] | [
false
] | Examples: kiloJoules per meter squared per year---kJ m yr Biomass is measured in grams per meter per year g m yr Why are the exponents negative? wouldn't those signify the reciprocal of a year or 1/meter Am I thinking to strictly mathematical in a scientific field or is my math incorrect? | [
"I don't quite follow your question. Writing kJm",
"yr",
" is the same as writing kJ/m",
"yr- perhaps the former is sometime preferred because it only takes a single line, but they are identical statements. "
] | [
"Thanks, I was thinking about the math wrong. I gotcha now"
] | [
"Biomass is measured in grams per meter per year g m",
" yr",
"Biomass is measured in grams (or kg).",
"Biomass ",
" is measured in grams per square meter.",
"Biomass density ",
" is measured in grams per square meter per year.",
"The units of m",
" and yr",
" do not exist on their own (at least, ... |
[
"Differences between the Pfizer/BioNTech vaccine and Sputnik V?"
] | [
false
] | Yesterday's news seem to have given everyone a much-needed dose of optimism. Understandably, when Russia announced its own COVID vaccine a few months back, the reaction was much less enthusiastic. I'm from Moscow, and, although anecdotal, don't know a single person who is planning to inject Sputnik V, primarily due to ... | [
"off the top of my head I don't know the science behind the Sputnik, but I do know that the original trial only tested it in 73 patients, whereas the Pfizer vaccine has now been tested in over 43,000 patients.",
"Sputnik could end up working fine and being safe, the issue - for the scientific community - is that ... | [
"They do work somewhat differently, yes.",
"Sputnik V is and adenoviral vector vaccine. A vector is a virus that has been modified to remove the genes that allow it to reproduce in the body so it can't make the recipient ill, but it still has the structures/genes that allow it to enter the body and permeate the c... | [
"One big difference between the two is that human adeno vector vaccines have been tested since the 80's on long term adverse effects, and that's why they being released only for some years. This is not the case for mRNa vaccines, we shouldn't call the \"new vaccines\", but prototypes.",
"mRNA vaccines have potent... |
[
"We have different types of speech in different parts of the world, do animals as well?"
] | [
false
] | Say a Bengal tiger raised in Africa compared to a Bengal tiger raised in China. Would they both make the same sounds as each other? | [
"Similar question from a few months ago",
"Birds, whales, dogs and possibly cows have been found to have \"regional accents\".",
"I imagine the rarity of a tiger makes studying something like this a bit difficult but I wouldn't be surprised at all if they had 'accents' as well."
] | [
"An important caveat here is that various species differ appreciably in terms of (1) the diversity of their vocalizations and (2) the degree of biological preparedness they display for those vocalizations. I doubt very strongly that two ",
"lyrebirds",
" raised in different environments would sound similar."
] | [
"Wow. Really interesting thought. I have nothing to add but I just wanted to thank you for giving me something new to think about and look into. "
] |
[
"Why don't neutrinos interact with matter?"
] | [
false
] | null | [
"They only interact via the weak force and gravity, so the cross sections (basically the probabilities) for any scattering or reaction processes are extremely small."
] | [
"Piggybacking onto this, they don't interact electromagnetically because, unlike electrons, they don't have any electric charge (nor magnetic moment?), and they don't interact via the strong force because, unlike quarks, they don't have any 'colour charge'."
] | [
"Thanks"
] |
[
"If you exposed a conducting battery to light, would the reaction occur faster?"
] | [
false
] | Would the electrons move quicker and therefore produce more work and cause the battery to die sooner? | [
"Well, light wouldn't do anything more than the same amount of heat; it's not a photochemical reaction. But heating it would cause it to react faster. Not due to the electrons moving faster, but because the molecules would bump around faster and so the chemical reaction would occur at a faster rate."
] | [
"It would increase the power, but not the amount of energy in total. Specifically, the voltage drop for a given load would be smaller. You'd have a higher current because of that, so a greater number of electrons flowing for a while, but the total number of electrons transferred in the reactions is the same no matt... | [
"But since the chemical reaction occurs at a faster rate, would that increase the energy output like if you were to measure the amperes? If so, is this because there's more electrons flowing at any given time because the chemical reaction occurs faster?"
] |
[
"How does a computer know how much is 1 second?"
] | [
false
] | [deleted] | [
"Computers use a hardware device on the motherboard, usually an integrated circuit that is constantly powered, to keep time. Most real-time clocks count seconds using a crystal oscillator. This is a device that operates by converting the mechanical resonance of a vibrating crystal (like quartz) into an electrical s... | [
"Yes there is a tiny quartz crystal that vibrates at a known frequency when an electric current is passed through It. This is the same mechanism that is used in most non mechanical clocks, e.g. a battery powered wrist watch.\n",
"https://en.wikipedia.org/wiki/Quartz_clock?wprov=sfla1"
] | [
"Yup. Quartz is how Seiko, Timex, Casio, Texas Instruments, etc. almost killed the Swiss watch industry."
] |
[
"If a person were to be taking antiviral drugs when taking a viral vector vaccine, would that ruin the effect of the vaccine?"
] | [
false
] | null | [
"It would depend on the kind of antiviral. Since the viral vector in the vaccine does not reproduce any antiviral that operates to reduce reproduction would be moot. An antiviral that happens to block the receptor site where the virus can interact with the cell could prevent the virus from actually delivering its p... | [
"No.",
"“Because the current vaccines used in the U.S. are not live vaccines, no virus is produced and, therefore, an antiviral medication would not be expected to alter the response to the vaccine. However, if an individual is still experiencing symptoms from the viral infection for which the medication was pres... | [
"Viral vector vaccines rely on a virus to penetrate cells and to deposit DNA that encodes a protein, typically the spike protein, of the virus that the vaccine targets in order to stimulate an immune response.",
"The mechanism of most antiviral drugs is to prevent the virus from entering a cell and therefore the ... |
[
"Can someone help me gain a more quantitative understanding of the concept of invariance of the speed of light?"
] | [
false
] | Hello askscience, So I've heard and even explained a lot of the more qualitative, analogical, and heuristic takes on special relativity and time dilation and such. I'm by no means mathematically sophisticated, but I'm studying math and economics in school and I've done some linear algebra and multivariable calculus and... | [
"The speed of light is constant in all reference frames. Time and space distort to keep it constant (compared to your preconceived notions of them). Since light is a wave, this actually says something deep about physics - wave speed is calculated from a springlike term (the energy required to make an electric fie... | [
"Hi, I'll have a go at this, but I don't have a huge amount of time. A first remark: you need to specify that everything is measured with respect to some fixed reference frame R. As a direct consequence, if you measure the speed of your buddy, you will ",
" measure 0.6 c - 0.5 c = 0.1 c, but you need to use the "... | [
"As a layman, this is the way I like to think of it:",
"1) Light traveling from the sun to the Earth takes 8 minutes to reach you. ",
"2) From the perspective of a photon the trip is instantaneous.",
"3) The faster you travel, the closer to instantaneous your movement becomes from your perspective."
] |
[
"What causes gender dysphoria?"
] | [
false
] | null | [
"Gender dysphoria is incredibly controversial. ",
"First, some background biology is in order.",
"Genotypic sex essentially refers to the presence of the Y chromosome in men. Throughout development in utero, all individuals have both mullerian and wolffian ducts. In individuals with a Y chromosome, the wolffian... | [
"No, you need two sexes to reproduce. You could think that you are a badger for all the difference it makes, your sperm or your eggs still function normally."
] | [
"No, you need two sexes to reproduce. You could think that you are a badger for all the difference it makes, your sperm or your eggs still function normally."
] |
[
"If we know how tectonic plates moved in the past, can we accurately predict how they will move going forward?"
] | [
false
] | Im not sure this information would be useful to us in any way because of the amount of time it will take for the predictions to come to fruition, but are the movements of the plates predictable or random? | [
"We can project the future motion of the plates, but only up to a point with any accuracy. To back up, through a variety of techniques we can measure and reconstruct average plate motions and directions in the past, e.g., from plate circuits, paleomagnetic data, reconstructions from sea floor spreading, etc. (e.g.,... | [
"There is a lot we don't know about mantle plumes, but modeling suggests that they operate on scales between 500 million years and 2+ billion years, making them somewhat \"stable\" in that sense, with only a handful (around a dozen or more?) active today. Though we dunno how quickly a new one might form or old one ... | [
"However, an existing plume doesn't mean an erupting plume - which is what is believed to cause massive basalt floods (such as Deccan Traps, famously) which are a major source of continental reorganization as new crustal material is formed.",
"This isn't really accurate though. Flood basalts and other large igneo... |
[
"Are there potential applications (even if theoretical) for the Bose-Einstein condensate? And really, what is Bose-Einstein condensate?"
] | [
false
] | I learned about this peculiar state of matter only recently (and only learned that it exists - nothing more). I don't exactly understand what it is. I gather that it is a special state of matter that does not occur in nature, and can only be achieved at temperatures close to absolute zero. I guess I'd just like to hear... | [
"Possible applications as an accelerometer to use for navigation in spaceships."
] | [
"I've heard some talk of using BECs in atomic interferometry, typically in the context off gravitational wave detection. Imagine that you have a coherent BEC beam which you can split into two, and later recombine somewhere down the line. If the two beams pass through different gravitational fields, they will pick... | [
"How?"
] |
[
"Is it possible for a tectonic plate to crack into two?"
] | [
false
] | I got bored and was looking at plate tectonic map on Google. I noticed the tip of africa was sandwiched between plates. I wondered if a situation was to occured that caused that piece to snap off | [
"This question comes up from time to time. It's known as rifting and it's a routine process. Fairly slow though. Geological forces stretch and thin the plate. If it's stretched and thinned enough the underlying mantle that fills the space melts and erupts, creating a new oceanic spreading ridge.",
"I'm not sure w... | [
"Besides the mechanism cantab mentioned, you get oceanic plates breaking apart when subducting under continentals. Like on the North American west coast, where you'll find several small plates that are thought to be remnants of old plates that have been pushed under America. Same probably goes for the mess that is ... | [
"Yes indeed. It’s called rifting. The opening of the Atlantic, known as the ‘Atlantic rifting’ about 200 million years ago is one of the best known examples. The fossil record of the Atlantic rifting is what gave rise to Wegner’s theory of plate tectonics."
] |
[
"So when I close my eyes, I don't 'see' anything, but I still see something black. Do blind people also see something black?"
] | [
false
] | null | [
"IIRC from an article I read once, people born blind never develop the visual cortex so they literally have no concept of vision. It would be like a Dolphin asking us what we perceive with our lack of Sonar.",
"If you lose your vision later in life then supposedly you see \"black\" "
] | [
"I remember on an AMA a long time ago that someone said if you were born blind, it was like seeing out of your elbow. You just don't."
] | [
"I'm deaf. There's no such thing as silence for me."
] |
[
"How much pressure is necessary to form a bruise?"
] | [
false
] | Is there any typical value? What would be your approach to this kind of problem? Edit: Yes, about human bruising. How about approximating a fall on a knee/elbow? | [
"There are way too many variables to be able to say, \"This amount will bruise.\" When we're in school we learn all about platelets' function, which is clotting blood. That is such an incredibly simplified version.",
"The coagulation cascade",
" is a complicated process in which each step's functionality has a ... | [
"I don't know about people, but for fruit the \"bruise threshold\" is measured in how high you need to drop it from to bruise it. According to ",
"this",
", it's about 2 cm."
] | [
"Look a bruise is just internal bleeding, this will depend on what kind of tissue it is affecting, what it is being hit with and what the properties of that area, and the person who it belongs to"
] |
[
"What amount of impact energy did medieval siege weapons reach?"
] | [
false
] | I am thinking about battering rams (logs suspended from frames, not the ones that were carried), trebuchets, catapults, ballistas, and so on. I've been searching the web for a bit, but there seems to be no real information on this... | [
"Using these numbers: ",
"http://en.wikipedia.org/wiki/Trebuchet",
"In 1421 the future Charles VII of France commissioned a trebuchet (coyllar) that could shoot a stone of ",
", while in 1188 at Ashyun, rocks up to 1,500 kg were used. Average mass of the projectiles was probably around 50–100 kg, with a range... | [
"Lets look at the trebuchet (",
"http://en.wikipedia.org/wiki/Trebuchet",
") as an example that should provide one of the higher energies. Wiki says: ",
"Average mass of the projectiles was probably around 50–100 kg, with a range of ca. 300 meters.",
"Let us make the assumption for simplicity that there is ... | [
"For comparison, a modern hand grenade (M67) has a yield of ~750 kJ, equivalent to a large (but not the largest) trebuchet.",
"Edit: The trebuchet would still be much more effective for destroying walls than the M67 grenade. The grenade is a weapon designed to throw shards of metal in all directions, while a treb... |
[
"If our ears locate the direction which a sound comes from by the time lag between our two ears, how does it determine if it's in front or behind of us?"
] | [
false
] | null | [
"Observe your reaction next time you hear a sound whose source is not visible or immediately apparent. You’ll notice that — while you will likely have an initial impression of which side it comes from — you will instinctively react by turning/angling your head to some degree, which is the process that really allows... | [
"The various shapes and indentations of the earlobe affects soundwaves in ways the brain already knows. By working backwards from the received sound, the brain can figure out which features of the earlobe the sound traversed"
] | [
"It's a good question. ",
"When using stereo headphones, you certainly don't get any sense of \"front\" or \"back\", so how does this work in real life? The simple answer is, there is more to \"hearing\" than just the ears. Sound vibrations are also picked up by the skull itself, and this information transmitted ... |
[
"If a glass jar free falls and shatters on the floor, can any shards fly higher than the altitude from which the jar fell?"
] | [
false
] | null | [
"There's no physical law forbidding it, but the center of mass of the shards will never be higher than the center of mass of the original object at the drop point.*",
"*Assuming a regular system in which potential energy constitutes the entire available energy (e.g., no explosive chemical reactions, etc.)."
] | [
"As a proof of the basic concept, see ",
"The Galilean Cannon",
"."
] | [
"An individual shard can go higher, since the energy needed is much less than potential energy from the entire jar.",
"The collection of shards will not."
] |
[
"How have our bodies evolved to metabolize chemicals such as pharmaceutical drugs that would never be found in nature?"
] | [
false
] | null | [
"Well, it's not that we evolved to metabolize drugs but rather we design drugs that can be effectively metabolized and used by our specific physiology. ",
"Other chemicals that our bodies may come across are usually dealt with by nonspecific ligand receptors, meaning receptors that tend to recognize a class of mo... | [
"I used to work in a toxicology lab, and there are a variety of reasons that we can be naturally resistant to non-natural compounds. Two big reasons are the ",
"Cytochrome P450",
" system which can ",
" a compound and the ",
"ABC Transporter system",
" which can ",
" a compound.",
"This nice image",
... | [
"We possess many enzymes for for detoxifying compounds, courtesy of our vegetarian ancestors. We can eat many things that would kill pure carnivores such as cats and dogs. Some animals, such as rats, possess an even more powerful set of detoxifying enzymes, and they can eat many things that would kill even us."
] |
[
"How much have we evolved as a species over the past 100, 200 or 500 years, in contrast to how much we have evolved over the past 200,000+ years?"
] | [
false
] | We've certainly changed over the past few hundred years. Per Wikipedia, our anatomically similar ancestors came into being 200,000 years ago while we reached full behavioral modernity about 50,000 years ago. Is the rate of our evolution changing, either slower or faster? Rather, are we evolving at an exponential rate? ... | [
"There is a whole lot of debate among anthropologists how much it's appropriate to apply evolutionary theory right now.",
"Some evolutionary-minded folks want to recode all of anthropology and history in evolutionary terms; they say everything's \"evolution\". Ideas, people, ethnicities, etc.",
"As for actual ... | [
"I've always pondered whether or not the fact that we now modify our environments to suit ourselves rather than vice versa, coupled with the fact that in a lot of places natural selection is essentially non-existent, would more or less mean that natural evolution wouldn't continue. I imagine that because of the amo... | [
"Who adapts faster than humans? Nobody.",
"Bacteria."
] |
[
"How are Countries named in their non-native languages?"
] | [
false
] | Even in multi-lingual countries, how did they decide what the place should be called in the different languages? Where does the English name for Germany or Austria come from when their German-language names are vastly different in pronunciation and literal interpretation? Who took "Nippon" and said, "yeah, that's 'Japa... | [
"For your specific examples: Germany was a \"region\" of many small kingdoms, duchies, counties, principalities, etc. long before it became a single country in the 1860s. The word \"Germany\" was based on what the Romans called part of the area ",
". Germany has different names in different languages, partly beca... | [
"For Japan in particular, you google \"etymology of Japan\", and you get this page ",
"https://en.wikipedia.org/wiki/Names_of_Japan",
"in summary, basically the Kanji Nippon is read as Re Ben, which sounds like Jepang to Malay and Indonesian, and the European first heard about this country from them, and so it ... | [
"As you say, ",
" is a Latinization of Old High German ",
", but that itself is likely a translation of Latin ",
"!",
"In regards to Germany being a region of many small principalities (the ",
"), there was no real question from the emergence of the Ottonians-on that \"Germany\" was a \"thing\". There has... |
[
"What is the biological reasoning behind humans gaining pleasure from adrenaline-inducing activities like amusement parks and skydiving while other events like car crashes and impending danger do not give the same pleasure? Do other species of animals gain the same pleasure?"
] | [
false
] | [deleted] | [
"It's exactly the same feeling except there's safety measures built into things like extreme sports and amusement parks which are missing from actual danger. They're designed to give the experience of danger, and the reward for surviving the danger, without actually putting yourself in harms way.",
"The reason pe... | [
"It'll vary, if they trust the person enough and have the personality for it they could enjoy it."
] | [
"So when people take animals sky-diving, those animals are actually terrified?"
] |
[
"Are quantum entangled particles subject to time dilation?"
] | [
false
] | Let's suppose you have two twin astronauts as described in the Twin Paradox thought experiment. Each of them is given one particle of a quantum entangled pair for safekeeping. One twin remains on Earth, while the other flies away for several years traveling at nearly the speed of light. When he returns to Earth he is... | [
"Just going to copy my post below:",
"This the exact opposite of what entanglement is. You're just describing classical information, do you think there would be all this fuss over quantum mechanics if a quantum state was just classical information (left and right handed gloves placed in separate boxes)? What you'... | [
"Depends on your interpretation of QM. We've proved there aren't local hidden variables, but there are still non-local deterministic interpretations. Many-worlds, pilot waves, etc."
] | [
"I take some issue with this statement.",
"Nothing is \"collapsing\" but our ignorance of the actual state",
"Isn't it a core tenet of quantum mechanics that it is NOT deterministic? The particles are not in some defined/\"actual\" state that we don't know yet, they are genuinely probabilistic until observed or... |
[
"What molecular properties make a substance a good or bad conductor of electricity?"
] | [
false
] | null | [
"It's related to the ",
"electron orbitals",
" of a given substance.",
"Metal atoms have D-Orbitals, which are large, easily polarized (Deformed), and well shielded from the nucleus. Because of this electrons can move fairly freely through metals while still being stabilized by the metal nuclei at the core.",... | [
"How do f-block metals fit into this then? Also, this seems to apply to pure substances only... are alloys not used as conductors? "
] | [
"Metallic bonding",
". Metals are essentially nuclei awash in a sea of delocalized electrons. It is easy to make these electrons move (conduct)."
] |
[
"How did they discover that a photon was the smallest unit of light, and how did they fabricate an instrument that could shoot individual photons?"
] | [
false
] | null | [
"It really started with the \"Ultraviolet Catastrophe\": classical physics predicted that black bodies should emit light at all frequencies, with the intensity going up for higher-frequency light. However, around the ultraviolet range, the classical prediction broke down and didn't explain the black body spectra ob... | [
"The catastrophe of it was that it was predicted that radiating bodies should radiate an infinite amount of energy, since they would emit radiation at all frequencies. Something red-hot, for example, has a peak at the wavelength of red light, but classical physics predicts that it will emit some infrared radition, ... | [
"Could you explain the UV catastrophe a bit more for the non scientifically literate?"
] |
[
"What kind of information can we obtain from mars with the new MSL cameras?"
] | [
false
] | As in the title, i would like to know what kind of scientific information we can obtain from using the MSL cameras and their new high definition panoramas. Will it just be simple geographic observations, or can maybe some 'hard science' be done to. Thanks. | [
"If you don't get your answer here, try ",
"/r/geology",
"."
] | [
"What makes you say geographic observations aren't hard science? "
] | [
"I knew i would get this comment. I know you can get hard geographic observations and geology is hard science, but i was wondering whether this could be obtained from photos alone, or could you only make general/sweeping statements about the geology."
] |
[
"How did DNA, such an extremely efficient coding system for the development and functioning of all organisms, just happen to come about?"
] | [
false
] | It seems like its too perfect for it to just happen by chance. The universe is about 13 billion years old. First life on earth is 4 billion years ago. So in just 9 billion years, random chemicals mixing around just happened to come together to create such a beautiful mechanism for life? I'm just wondering how something... | [
"Not only is 9 billion years a huge amount of time for humans, who experience time on the orders of seconds/hours/decades, but for individual atoms and molecules, it's significantly longer.",
"The typical vibrational frequency of an atom is 10",
" times per second. And in a crystal lattice, the amount of times ... | [
"So in just 9 billion years, random chemicals mixing around just happened to come together to create such a beautiful mechanism for life?",
"I don't think you comprehend just how long 9 billion years is. I don't think any human really can.",
"Can someone explain how it originated?",
"We don't know. There ar... | [
"The immense dimensions of time are so truly mind-boggling to me.",
"Now if all ",
", all of human history, all our wars and peaces, conquests and discoveries could happen in the past 10,000 years (a mere 500 generations), and all our evolution since the demise of the ",
" could happen in the past 65,000,000 ... |
[
"Do matter and antimatter always annihilate instantly on contact, or does the process have some kind of a 'half-life' like particle decay?"
] | [
false
] | null | [
"The latter is more correct. Consider, for example, positronium, which is an \"atom\" of an electron bound to a positron. It has a half-life of about 120 picoseconds."
] | [
"Positronium can be excited into metastable states that last longer. It can also form a molecule with hydrogen, positronium hydride.",
"They are all examples of a higher energy quantum state decaying into a lower one. "
] | [
"Thanks for the response! Do we know of any other matter-antimatter bound states that last longer, perhaps for timescales on the order of what humans can perceive?",
"Also, as an interested layman, I'm a bit curious if my intuition is correct in assuming that annihilation and particle decay are related in some wa... |
[
"Can you make a nuclear bomb with any element?"
] | [
false
] | Could you use an element like gold, or sodium, instead of uranium? | [
"No. There are a few basic requirements that a nuclear package should meet in order to be useful. First, you need nuclear reactions that release energy, and as much of it as possible. Second, you need this reaction to be as easy as possible to initiate; you don’t want a large energy barrier to overcome. In broad st... | [
"There are other fissile nuclides. ",
"Here",
" is a chart.",
"Lower down in that article, under “Nuclear fuel”, they mention the criteria I had above, as well as some of the more detailed ones that I swept into the catch-all of “engineering problems”.",
"So you can get a sense of how many fissile nuclides ... | [
"If you want to use fissile nuclides for a fission bomb, this limits you to a handful of heavy species. Engineering/practical constraints further limit you down to uranium-233, uranium-235, plutonium-239, and plutonium-241.",
"Since we are talking about an hypothetical situation, can we relax those constraints?",... |
[
"I'm curious about the evolution of viruses. There are DNA and RNA viruses, but what are the advantages of having one on the other nucleic acid? Did the DNA viruses evolve from the RNA viruses or did they both evolve separately? Are DNA viruses more stable outside a host?"
] | [
false
] | null | [
"Simply said, RNA is more reactive and suitable for being used as a catalytically active entity. But a cost for this inherent excitedness is instability (though stable compounds are not necessarily non-reactive, e.g. ketones). This means that RNA is prone to errors, therefore mutations, which alter its function.",
... | [
"To expand on why the replication error rate is lower than expected for an RNA virus...",
"SARS-CoV2 has an RNA polymerase with 3'->5' exonuclease activity which provides a rudimentary proofreading function during RNA genome replication. ",
"This is one of the reasons despite having a ssRNA genome which typical... | [
"To what he said, it is likely viruses evolved in both ways, some from the ground up, while others were stripped down."
] |
[
"What factors contribute to the sex of a baby?"
] | [
false
] | There is so much anecdotal shit if you Google this, and there's only one previous post in AskScience that I can find (with only one comment). It seems that the main gist is that X-carrying sperm differ from Y-carrying sperm cells. This is the crux of the issue: are they different, and if so, how are they different? I u... | [
"The short answer is no. The long answer is that we have discovered several factors that influence sex on a population-wide scale. For example, during and after wartime, male babies are slightly more likely. ",
"Source",
" Also, women who are chronically stressed or in poor health are slightly more likely to gi... | [
"I'd like to know if there are statistically significant steps you can take to influence the gender that you conceive? "
] | [
"It could be possible, but not through anything like \"eat more cabbage\".",
"If you isolate the x or y chromosome from a male sperm cell. Female cells are always XX while male cells are XY, re-productive cells are half cells, so in a woman's case it's either X1 or X2 and in a man's case X1 or Y1. But isolating a... |
[
"I just heard that if you are near a nuclear explosion but outside of the hotzone where everything is destroyed the best thing to do is to get to a basement or garage and stay there for 7 hours-2 days. I understand the basement, but what is it that makes a garage any safer than inside a house?"
] | [
false
] | Aren't the walls just as thin? Many garages have windows, and it is not unheard of for someone to need to go outside to get from the house to the garage. | [
"You don't want a ventilation system bringing in outside air."
] | [
"Are you certain they weren't specifically talking about ",
" garages? That would seem much more reasonable."
] | [
"I don't think a ventilation system would be a factor in most cases. Most likely there would be massive power outages in the surrounding areas."
] |
[
"Do atoms or any other minor particle have a unique \"fingerprint\" or unique measure of information that makes them distinguishable from their similar others?"
] | [
false
] | [deleted] | [
"So to start at the largest scale, we can tell atoms from different elements / isotopes apart because they have different number of protons and neutrons in the nucleus. ",
"Fundamental particles are indistinguishable from other particles of the same flavour. (I can tell the difference between an 'up' quark and a ... | [
"No - unless they belong to a different element, have a different number of electrons or similar things. And, surprisingly, we can test this exactly.",
"Particles are either fermions or bosons, and follow the Fermi-Dirac or Bose-Einstein statistics, respectively. These statistics tell us how likely it is to find ... | [
"Great explanation thank you for your time and your answer"
] |
[
"If curlier hair retains heat better than straight hair, how come Africans tend to have curly hair, while most Europeans have straight hair?"
] | [
false
] | My only guess is that curly hair not only helps retain body heat, but it also helps deflect heat from the sun, while straight hair helps to absorb heat from the sun. | [
"People with darker skin have coarser hair because of the higher amount of ",
"melanin",
" in their hair. It isn't retaining the heat - the melanin is protecting the body from the UV rays of the sun. Also check out ",
"this",
" link from wikipedia."
] | [
"Curly hair also retains moisture really well."
] | [
"Curly hair and more air space. air is the only insulator. \nall that crap in your roof is just little pockets of air.\nwhy is wool so warm? little pockets of air.",
"Curly hair doesn't just retain heat it keeps it out too. ",
"In Africa the climate is kept away from the scalp via curly hair.\nIn Europe the war... |
[
"Why do proteins misfold?"
] | [
false
] | null | [
"Proteins are dynamic structures which are jiggling all the time. Most proteins execute some sort of dynamic function as well, such as enzymes that require them to be able to change shape in response to some stimulus. This means that the energy landscape around a \"native\" conformation is not too steep and the pro... | [
"There is roughly a continuous distribution of energies within a system. Some protein will have higher internal energy at some point from a random collision or an errant chemical reaction, or temporary destabilization of water structure due to crowding... just random disturbances. The misfolding can be irreversible... | [
"Can you elaborate on what a “high energy event” is?"
] |
[
"How does carbon-dating date the age of a man-made object?"
] | [
false
] | [deleted] | [
"As other posters have mentioned you can only carbon date organic matter (or matter that was formerly living). It can not be used to date marble. ",
"It relies on the basic assumption that the ratio of radioactive carbon (C14) to normal carbon (C12) in the atmosphere has been relatively constant in the past. ",
... | [
"You can't carbon-date a marble pillar; you use it to date formerly living things.",
"And yeah, if you took a piece of wood 40,000 years old, and during its history at age 20,000 years it was carved into a spoon, carbon-dating would tell you it was 40,000 years old not 20,000. But who goes around using 20,000 ye... | [
"Carbon dating requires knowledge of how much of the carbon isotope had to have been present at the time you wish to date. ",
"As for the pillar example, suppose ",
" a historian can confirm that the marble was always mined from a certain place just a year or so before the pillar is carved. ",
"Anywho, you n... |
[
"What is the difference between internet streams and television broadcasting? engineering/computing"
] | [
false
] | [deleted] | [
"Internet streams are unicast/multicast while television is broadcast",
"Thats one difference",
"Also, when you have cable TV, ALL the channels are being sent on that particular cable from your cable operator. Your TV just decodes the one you want to watch",
"In case of internet streams, an individual stream ... | [
"Cable is broadcast, not multicast"
] | [
"Cable is broadcast, not multicast"
] |
[
"If stars in a galaxy increase in velocity the further they are from the center, why do galaxies have spirals? Wouldn't spiral arms indicate slower speeds as you approach the edges of a galaxy?"
] | [
false
] | I understand dark matter plays a role here, keeping the galaxy spinning as one like a dinner plate. Does this indicate the spirals form before enough dark matter appears? | [
"Despite normal intuition when looking at a face on picture of a spiral galaxy, the spirals aren't exactly what they would seem. They are not concentrations of stars as you might assume and they have little to do with the motion of the stars. They are in fact density waves with in the material of the galaxy, namely... | [
"Clear and concise answer. Thank you for that.",
"I watched a few videos covering the density waves and it makes perfect sense to me now."
] | [
"A side note: the galaxy does not spin as one. All stars in the outer disk have approximately the same rotational speed (this is a consequence of dark matter) but the outermost stars travel further. This means the inner stars of the galaxy have a shorter orbital period."
] |
[
"How close was the moon 2.5 billion years ago? What effect did it have?"
] | [
false
] | From what I gather, there was a small supercontinent called Ur during this time, and everything else was ocean. If I'm a human (with an oxygen tank, since this is just before the Great Oxygenation Event) standing on Ur, overlooking the ocean, what do I see? How big does the moon look? How large are the ocean's waves? (... | [
"Wave height is mostly determined by the winds. Tides are determined by the moon. There may be some secondary effects of tides on waves, but the most noticeable difference would be the tides.",
"Apart from that, the tidal influence also affects the not-quite-solid (especially back then) mantle of the Earth, causi... | [
"Okay, thanks for clarifying tide vs waves. If the days are much shorter, the Earth is spinning much faster (since the moon is much closer). Would this rotation affect the Coriolis effect and increase average wind speed?",
"Great tidbit about the geologic activity, that makes sense. Thanks!"
] | [
"This",
" is not quite what you are looking for but has a fascinating treatment some very strange stuff that was going on millions of years ago. There is a bonus speculation about how fast Usain Bolt would need to run across a planet to live in a perpetual sunrise. Hope this helps."
] |
[
"Why and how do spiral bands form in a hurricane?"
] | [
false
] | I understand that, as warm air rises and creates a low pressure zone, high pressure winds rush in, warm, begin to rise in a spinning motion (due to the fictitious Coriolis force and around a region called the eye), and then condense into clouds as they cool higher up in the sky. This cool air then sinks to repeat the ... | [
"The clouds bands are found where there are bands of potential vorticity. Potential voritcity is an dynamical variable based on angular momentum and mass conservation that is used for studying atmospheric and ocean dynamics. The bands of potential vorticity spiral because of nonlinear Rossby wave propagation tha... | [
"Yes, I understand that. But I’m asking about the formation of the spiral bands - the areas where cloud formation is the densest and rainfall is the heaviest"
] | [
"Because the air and earth are revolving around the the axis of the earth, so angular momentum at a scale of a hurricane twists into the spiral shape you see, clockwise for Southern Hemisphere, counterclockwise for northern"
] |
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