title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Does dissolution affect volume differently than just addition?"
] | [
false
] | Say I have two glasses of x amount of water. If I add y amount of salt to one and y amount rocks to the other, will both volumes be x+y | [
"Yes. Well, sometimes. Take alcohol, and add water. The total volume won't be x+y as the tiny water molecules \"nest\" themselves in the spaces in between the way bigger alcohol molecules, taking up less space in the end. This isn't always true though"
] | [
"For dilute aqueous solutions one can assume that the solute does not take up any volume. As it gets more concentrated, however, this is not true and the volume will change with more solute added.",
"So for you, a little salt will not change the volume. 10% salt probably will."
] | [
"Not necessarily. In case of salt (NaCl) the volume will be less than x + y. The term you're looking for is \"apparent molar volume\", see: \n",
"https://en.wikipedia.org/wiki/Apparent_molar_property",
"and also\n",
"https://en.wikipedia.org/wiki/Partial_molar_property"
] |
[
"Are people with high reward dependence more affected by low expectancy?"
] | [
false
] | Since people high in reward dependence ( ) are finely tuned to rewards, I would think that low expectancy ( ) would cause them to procrastinate more than people with low reward dependence, all other things being equal. Do you agree? | [
"Perhaps I don't understand your question, but I don't really see them as related. \"Expectancy\" is the level of perceived behavior control or self-efficacy in relation to a particular behavior (see Theory of Planned Behavior, Icek Ajzen 1985). We approach each behavior with a certain subjective belief that we wil... | [
"I interpret OP to mean that people who seek reward are unlikely to begin a task which they perceive as having little to no potential for reward. I think OP wonders if that form if procrastination outweighs the \"more traditional\" form."
] | [
"Thanks. I think, then, that not taking on tasks with low reward is not the same as procrastination. It is the wrong label. No one can do everything. Maximizing reward involves careful task selection. Reward seekers are likely to be active on tasks that provide rewards and likely not to be active on unrewarding tas... |
[
"How did astronomers discover the expansion of the universe was accelerating, given the huge uncertainty the Hubble constant?"
] | [
false
] | According to my physics teacher, depending on who you ask, they would say the Hubble constant is anywhere from 60-80km s MPc . But if that's the rate of expansion of the universe, how could they prove it's increasing if they don't know what the actual value of it is? | [
"Having some uncertainty doesn't mean we have no idea what's going on. If we say it's from 60-80 km/s/Mpc, then we really do mean it. If we said the Hubble constant is somewhere from -50 to 200 km/s/Mpc, then it would be okay to say that there is quite possibly no trend. But if we're saying it's 60-80 km/s/Mpc it m... | [
"Astronomers use a type of supernova called type 1a supernovas to measure redshift. Since type 1a supernovas always have the same absolute magnitude (brightness) and can be seen from very far away, it is possible to measure redshift extremely accurately. The Hubble constant is proportional to the redshift divided b... | [
"The Hubble parameter (not a constant) is just a scale factor. If we are wrong by 10% that simply means that our distance scale is off by that amount. It's like using a meter stick that is only 90 cm long. It is still useful for comparing the distances to objects. For example, we can compare the speeds of obje... |
[
"How can energy be quantized if both speed and wave length are both continuous quantities? How discrete is energy?"
] | [
false
] | We all know that energy of electromagnetic radiation is equal to Planck's constant times the frequency. But both wave length and speed are continuous quantities that can take on any value, so how can it still be discrete? Thanks! | [
"The range of energy of electromagnetic radiation is not discrete.",
"EM radiation does come in discrete packets, though (photons).",
"Maybe you were confusing these two things?"
] | [
"Energy is not quantized. What is quantized is the energy ",
". A more palpable way of saying it is that a wave of a given frequency or wavelength has a ",
".",
" This was not meant to be a reply to dukwon above, who has a fine answer."
] | [
"Second quantisation is when you describe a system in QFT using a basis composed of the number of particles occupying each state.",
"First quantisation is just using states as a basis.",
"The advantage of (or need for) second quantisation is that it facilitates being able to describe interactions where particle... |
[
"How does stress actually make you ill?"
] | [
false
] | I've been told, and read many times that stress makes you ill, and I don't doubt it; but how does it happen, biologically? It's always puzzled me as to how what is essentially an emotion or a feeling can make you physically ill. | [
"The answer here is a hormone called cortisol, as other posters have pointed out.",
"Whenever you have stress, you will get a hormone from your adrenal gland (your adrenal gland looks like a beanie hat that sits atop each of your kidneys) called cortisol. This hormone was designed with real stress (fight-or-fligh... | [
"Actually the mechanisms are pretty well understood, go grab a physiology textbook if you have any questions about the stress response.",
"Yes, the hypothalamus and pituitary gland are involved, but cortisol is released from the adrenal glands which sit on the anterior of the kindeys (closest to the head).",
"T... | [
"sort of. cortisol suppresses your immune system, which weakens your ability to fight off infections. the reason for the suppression is that maintaining the immune system takes a ton of extra energy that cortisol redirects into being used against external threats."
] |
[
"How do I stop crystalization in a non-hygroscopic sweetner?"
] | [
false
] | How do I prevent Erythritol from recrystalizing in drinks, candies, baked goods, etc? I've asked this in askcullinary and nobody could help me. It dawned on me it may be more of a science question. My diabetic father is eating himself to death. I am desperate to make some low carb deserts that will fool him and hopefully convince him to switch to some of my recipes i'm trying to work on. (Wikipedia) is the best candidate so far, there is absolutely no aftertaste. I'll spare you all a description, you can click the link for more info. Please correct me if I'm asking the wrong questions. Unlike sugar the erythritol does not readily absorb water, it repels it. That seems to cause it to easily crystalize. For example, when adding them to a cheesecake it will be fantastic at first. Twenty-four hours later and the sugar has recrystalized and the treat now feels as though it has sand inside it. Gummy-Bears were awesome for about 10 minutes, then opaque speckles apeared which started growing till the whole candy became crunchy. I've heard of mixing sugar with corn syrup and the long molecular chains disrupt the sugar recrystalizing. This (even if it worked) isn't an option because of the carbs. I've heard cream of tartar can help prevent sugar from crystalizing. Is this because of the acidity? I'm willing to do tests, but I was hoping I could get some direction instead of baking $20-$30 failures every day. | [
"Amateur candy-maker/chemist here. ",
"The usual MO is to add glucose/corn syrup/inverted sugar to a sucrose mixture to stop crystalization. Corn syrup is glucose, mostly. The similar-but-not-quite-the-same structure of sucrose to glucose or other sugars means the crystals can't form efficiently. Even with su... | [
"The hygroscopic properties have nothing to do with it. A sweetener that doesn't affect blood glucose levels, as is the case with erythritol, is what is sought after. However, conventional sugars (sucrose, glucose, fructose) are much easier to bake and cook with, as this is what we are used to."
] | [
"The mixing is a good idea. I'll have to read up on the digestive stability of all the other ones. Thanks!"
] |
[
"When a ventilator is removed from a patient in order to allow them to die, is it possible for that patient to feel as though they are suffocating? And if so, can any steps be taken to prevent or mitigate this?"
] | [
false
] | [deleted] | [
"Patients are generally taken off ventilators when they are ",
"bread dead",
", and since there is no brain activity, the patient should, in theory, feel nothing.",
"Brain death is not the same as ",
"persistent vegetative state",
" or being terminally ill. I do not believe patients are taken off respirat... | [
"Very unlikely. Even if the person isn't unconscious from their illness or injury the pain killers and sedatives used should prevent any awareness of the situation and prevent any suffering. ",
"In the uncommon situation where you believe that there is a possibility of consciousness or awareness then you'd admini... | [
"Thank you for this response. This puts my mind at ease."
] |
[
"A gardener I know had an argument against GMO crops that to my layman mind seems \"sciency\" and makes sense. Is there any truth in this?"
] | [
false
] | [deleted] | [
"His argument has nothing to do with GMO and is an argument against monoculture, which we already practice quite extensively. \nMonoculture is the practice of using a single variety of plant across wide areas. It is done to control exact features of the crop so they are all identical and require identical managemen... | [
"He said that in a normal organic crop there is a lot of genetic diversity and in normal conditions won't produce as big a yeild as a GMO crop. ",
"Unless you are growing heirloom; all organic, conventional and GM crops come from the same hybrid stock. GM crops are not clones and are exactly the same as the othe... | [
"So they have to change the genes in every plant individually?",
"No, they just cross a hybrid crop with GM plants. The resulting plants have a group of GM \"Fathers\" but different \"mothers\". They only need enough GM plants to have broad enough genetic diversity. And additional genetic diversity comes fro... |
[
"Why is the \"Great Attractor\" further from the site of the Big Bang than the rest of the universe? How did it get out there first?"
] | [
false
] | [deleted] | [
"This is not the case, and that's not what the term Great Attractor means.You've got several misconceptions here.",
"There is no \"site of the Big Bang\" or center of the universe. The universe appears to be infinite in size. The bang happened everywhere in the whole universe, all at the same time.",
"There's n... | [
"To be fair, the Great Attractor is somewhat separate from the dark flow (and predates its discovery by a couple of decades).",
"You have a perturbation theory tag. Maybe I should get you to do my current project for me...",
"...",
"..."
] | [
"We know that all visible bodies are moving \"outward\" at an ever accelerating pace, and that some giant mass is probably \"pulling\" them.",
"We only know that galaxies are moving outward at an accelerating pace -- there is nothing to suggest that something is \"pulling\" them, and in fact none of our best mode... |
[
"After reading of a redditor that is collecting his earwax, I ask science: What kind of stuff and how much is coming out of the human body during an average life?"
] | [
false
] | [deleted] | [
"Excretion is any process which gets rid of unwanted metabolic products. This includes carbon dioxide, in the air we breathe out; nitrogen and salts in sweat; urine; bile pigments in faeces; hair and nails can also be considered excretion.",
"Copypasta'd from an overview of the excretory system.",
"Here's more... | [
"It'd be interesting to know how much 'dust' (skin flakes, dandruff) we create (and subsequently wipe off our house) each month?"
] | [
"Of those billions of skin cells, between 30,000 and 40,000 of them fall off every hour. Over a 24-hour period, you lose almost a million skin cells."
] |
[
"Interresting Physic-experiments with light bulbs?"
] | [
false
] | Hi there, . Some of my buddies, and I are doing some experiments with light bulbs, for a physic-assignment. Do you guys know any interesting/radical/fun experiments, involving light bulbs? Preferably experiments where you can calculate a specific result based upon the experiement, and/or its result(s). I want to thank you all in advance, for taking the time to read this. | [
"If you have something to measure light intensity and some filters:\nApply some voltage over the bulb and measure the light intensity at different wavelengths (using filters). Plot the intensity as a function of wavelength and compare to a blackbody radiation (and estimate the temperature). ",
"Repeat with differ... | [
"Thanks for the suggestion! We'll ask our teacher next class. Hopefully, its releated to the assignment, but to us, it sounds like it is."
] | [
"When I was taking a computational physics course, the prof mentioned that before we had supercomputers to do many body simulations (e.g. a bunch of point particles with gravity between them), a team used light bulbs to represent masses. Because, like gravity, light intensity goes as 1/r",
" they were able to com... |
[
"Are there any substances the Liver or Kidneys can't remove? Therefore in our blood forever."
] | [
false
] | null | [
"The liver can’t directly remove substances. It can, however, chemically break down many substances, rendering them harmless.",
"\nThe kidneys work like inverse filters, wih the ",
"Nephron",
" being the functional subunit.",
"\nAt the first step, everything under a certain size (approx. 60000 dalton) gets ... | [
"60000 dalton",
"The unified atomic mass unit or \"dalton\"",
"A dalton is a standard unit of mass that quantifies mass on an atomic or molecular scale (atomic mass). One unified atomic mass unit (dalton) is approximately the mass of one nucleon (either a single proton or neutron)."
] | [
"Re: The Kidney.",
"If it gets into the blood stream then it needs to go through the filter (the glomerulus) then it would need to be reabsorbed by the loop of Henle otherwise it would just go out through the collecting duct and urine.",
"If it can’t get through the filter (in cases where substances crystallize... |
[
"Why does the parsec exist?"
] | [
false
] | Why does the parsec exist next to the lightyear? The difference between the two (a parsec is just over 3 lightyears) means that using one or the other doesn't make much of a difference, does it? Most of the time I see distances to other planets expressed, it's in lightyears, too. | [
"The parsec is named for the ",
"allax of one arc",
"ond. Now parallax deals with perspectives, and how things closer to you seem to move more quickly than things that are further away, so the observed, or apparant shift with regards to more distant objects,and arcseconds are a measure of angle.",
"\n Now th... | [
"The Parsec is handy because it allows one to determine distance from earth by just measuring the parallax angle as the earth moves around the sun (which is why the Parsec is fundamentally related to the AU). That convenience aside, it is just another distance unit. If it is used to specify something like the lengt... | [
"And it is easier to measure an angle in the sky than to directly measure a distance. Indeed you don't even need a good distance estimate to start tabulating parallax angles. Only if you want to convert them to the distance we now know it represents"
] |
[
"Does the ringing in the ear emit an audible sound?"
] | [
false
] | null | [
"The \"ringing\" sound you hear is purely your perception, there isn't actually any sound or vibration being produced in your ear."
] | [
"Audiologist here - no, the ringing you refer to is called tinnitus and research at this stage is showing that it is central in nature (i.e. it is happening in the auditory centre /pathways in the brain, and is not coming from activity of the hair cells in the cochlea).",
"People often try to relate spontaneous o... | [
"There are some sounds people report hearing that can be heard or recorded from the outside. These are collectively called \"objective tinnitus.\" Someone already mentioned otoacoustic emissions. Many people have spontaneous otoacoustic emissions, meaning that their ear just starts emitting sound without any stimul... |
[
"Does light affect our organs?"
] | [
false
] | Since our organs are always in the dark, presumably one of the only circumstances they get exposed to light is during some sort of surgery. Does this sudden exposure to light have any effect on our insides? | [
"evolved (or were created with depending upon your theory of the origin of life)",
"Please refrain from making the implication that evolutionary theory and creationism are on the same footing here. Evolution is well substantiated and supported by thorough evidence, while creationism is an unsupported religious te... | [
"Tl;dr: UV light affects hematopoiesis so it occurs in the bones cuz it’s dark.",
"Idk about visible light but UV certainly does! We all know that it can cause DNA damage, thus leading to cancer. But I want to talk about blood, which is also susceptible to UV damage. In fish hematopoiesis (the process of making b... | [
"I do recognize your comment as being one regarding some fairly interesting concepts about blood production and it's sensitivity to light.",
"That being said, statements that are based strictly on belief don't belong in science (even if its just cursory). All data points to humans having evolved over millions of ... |
[
"Why doesn't the Alcubierre drive violate causality?"
] | [
false
] | With the understanding that don't exist yet, but are theoretically possible if we ever discover the requisite type of exotic matter. However, I was under the that any faster than light communication could result in a causality violation. So why are Alcubierre drives theoretically OK? | [
"It does. Anything moving faster than light can be used to communicate with the past, regardless of how it functions. There are other reasons why such a thing can't exist, see ",
"here",
"."
] | [
"No.",
"General relativity states that no two objects in the ",
" reference frame can go faster that the speed of light relative to each other - which would otherwise cause violations of causality and time travel.",
"How Alcubierre drives[1] move is different: they move in a ",
" reference frame of space, w... | [
"Although it is worth noting that historically, nonsense which is mathematically consistent has, on occasion, not been nonsense.",
": I'm not saying I expect negative mass to be a real thing. I'm saying we should not so eagerly dismiss it. ",
": I gave a brief summary of the physicality of Alcubierre drives "... |
[
"Pick a (uniformly) random integer 0 <= a1 < 1000, then pick another 0 <= a2 < a1, and so on. What is the expected number of steps to reach 0?"
] | [
false
] | null | [
"Hmm I should be packing but you caught my attention.",
"With problems like these it's often helpful to start smaller to build the intuition. Perhaps we can generalize the problem to E_x(Y), where x is the starting number and Y is the number of steps to reduce it to 0. We can find out that E_0(Y) = 0 and E_1(Y) =... | [
"Haven't done any programming for a few months and it would be nice to start doing it again. This seemed like an easy and fun enough thing to do. Wrote a short code that did what you described a 1,000,000 times and got an average of 7.486 random integers to get to 0 each time."
] | [
"For more info on the sum, these are ",
"harmonic numbers",
" H",
". What you found numerically was that for large N, H",
" is approximately log(N). This is actually the beginning of a series in large N for the harmonic numbers: ",
"H",
" = γ + log(N) + 1/(2N) - 1/(12N",
") + ...",
"where γ ~ .577 i... |
[
"The Pacific Northwest had a particularly wet and gloomy summer recently. As a consequence many trees that were not covered in moss are now blanketed. What effect does this blanket of moss have on the tree's health?"
] | [
false
] | [deleted] | [
"In terms of an exact relationship between the two, the moss wouldn't really have a negative effect on the tree. Mosses are not ",
"parasitic",
", and therefor would be simply using the trees as a ",
"substrate",
")(a medium to grow on).",
"Mosses are ",
"epilithic",
", therefor they will gather all o... | [
"Actually, a number of mosses (Sphagnum for instance) are known for their production of antifungal/antifeedant compounds. I'm not sure of the exact literature for their relationship with trees, but I'd assume that they may confer a certain degree of protection.",
"I'm not an ecologist though, so take what I say w... | [
"Actually, a number of mosses (Sphagnum for instance) are known for their production of antifungal/antifeedant compounds. I'm not sure of the exact literature for their relationship with trees, but I'd assume that they may confer a certain degree of protection.",
"I'm not an ecologist though, so take what I say w... |
[
"How do we have accurate records of hurricanes before satellites?"
] | [
false
] | For example, the 1899 San Ciriaco hurricane. We have a track for it, and even a time frame for intensification and weakening. | [
"Reports from different places at the same time and different times in the same place, from ships at sea as well as land-based observers. Put the data together like pieces in a puzzle. Fill in the holes with educated inference."
] | [
"Historical investigation can tell a lot. ",
"We know that a major super quake occurred in a Cascadia in 684AD because of very specific descriptions of a massive tsunami wiping out coastal settlements in Japan on November 29, 684, then they could estimate the actual date of the quake by how long it should take f... | [
"Going back even further -- paleoclimatology! Using lake cores, geologists can discover hurricanes hundreds of years in the past. Here's an article about it: ",
"https://insideclimatenews.org/news/01102019/hurricane-warm-water-climate-change-history-science-study-sediment-core-donnelly-muller"
] |
[
"It is a better strategy to attempt to appeal to the logical or emotional nature of a jury (or equivalent person(s)), given similar/equal strengths of each argument?"
] | [
false
] | My intention is to ignore any counterargument by an outside party in this case (i.e. considering only the target party's reaction to your argument). Stated more generally, is a person (or group of people) more likely to be susceptible to holes in an argument of logical vs. emotional nature? Also, are they more likely to be swayed by equivalently compelling arguments of one type vs. another? | [
"This is a difficult question to answer because the line between the emotional and the logical is not clear cut. I am going to try and answer you by separating out affect and cognition based on their deliberative components. ",
"Think of affect and cognition as two separate sources of input driving us towards an ... | [
"Interesting read. Thanks for posting it. I'm curious about something relating to your reply and the OP's question.",
"Do you think that the different sides in a trial would prefer more logical vs more emotional jurors?",
"The reason I ask is that several criminal case attorneys in the past I have spoken with... | [
"Hey, sorry for the delayed response. I think the answer to your question is related to the decision making strategy part of my original response. If you can determine that certain individuals are unlikely to engage in a deliberative, analytic process, even when instructed to do so, then you may be able to lessen t... |
[
"Helicase - how does it work?"
] | [
false
] | How does this enzyme decide to move its arms around to cut bits of dna up to make two copies of dna? This is what happens in your cells - but what motivates huge molecules to move around and do the things they do? | [
"I can't speak to ",
" they do it, but ",
"helicase",
" hydrolyzes ",
"ATP",
" to create the energy needed to do it's task.",
"Contrary to what you said, Helicase only unwinds the two annealed strands of DNA. If you think of DNA as two pieces of string twisted together, Helicase moves along the two stra... | [
"http://www.cs.stedwards.edu/chem/Chemistry/CHEM43/CHEM43/Projects04/HELICASE/FUNCTION.html",
"Best I could find!"
] | [
"Here's an article about how DNA helicase is recruited and loaded"
] |
[
"Why do cymbals/hi-hats still sound so horrible in high bit-rate mp3's?"
] | [
false
] | They sound like they're vibrating against a bunch of sand, or something. Are the standard codecs not suited to something unique about cymbals' spectrum of tones? If so, what? | [
"Cymbals are a \"",
"canary in the mine",
"\" indicator of low-bitrate mp3's. A crash cymbal's decay, for example, sounds quite different as you drop the bitrate while they generally sound fine at 320kbps and up. And yes, the standard codecs require a higher bitrate to encode such sharp, wideband sounds.",
"W... | [
"Mp3s are smaller than their wav counterparts because the encoder uses an algorithm to literally truncate the higher frequencies (where cymbal crashes occur). A frequency needs to be sampled at least two times to get an accurate \"idea\" of its shape and amplitude, so in order to sample 18,000Hz it needs to be samp... | [
"Sound about right. Just a side note, there's not a 1:1 correlation between file size and quality, even though as a general rule of thumb it does hold somewhat true. "
] |
[
"Could nuclear power plants on the moon transmit wireless energy to an earth based receiver?"
] | [
false
] | null | [
"It could, but there would be a few problems:"
] | [
"I disagree about that second part being a problem."
] | [
"Why? It would seem that a microwave beam or something carrying gigawatts would fry just about anything. Or, if it is not concentrated enough to do damage, the receiver on the Earth must be huge.",
"Furthermore, it would seem to me that the expected damage (chance of failure times damage caused in event of failur... |
[
"Why do batteries have internal resistance?"
] | [
false
] | College student here with some questions after my basic EMF physics lecture. The prof brought up a lot of things but can't go over them due to time constraints so I'd ask here. 1) Why do batteries have internal resistance? 2) How does a defibrillator return the heart to a normal beating rate when such a current through the body would stop it in the first place? 3) Why has the conventional "positive charges flow" not been changed now we know it is electrons that move through the circuit? Thank you everyone for your time, I'm sure to be back with more questions in the future. | [
"1) Why do batteries have internal resistance?",
"Well, imagine you're an ion heading through the electrolyte to be oxidized/reduced at the anode/cathode. You're going to be bumping into other molecules, giving off heat. ",
"2) It wouldn't necessarily kill someone, but anyway, the mechanism is that it depolariz... | [
"then they'd immediately short out rather than powering a circuit",
"No, they would work fine. The reason a battery does not short itself out, (there are some leakage currents), is that when no load is applied, the ",
"ions build up a barrier",
") that counters the electrostatic potential. The system just sit... | [
"then they'd immediately short out rather than powering a circuit",
"No, they would work fine. The reason a battery does not short itself out, (there are some leakage currents), is that when no load is applied, the ",
"ions build up a barrier",
") that counters the electrostatic potential. The system just sit... |
[
"Why aren't viruses considered alive?"
] | [
false
] | I get that we have a list of criteria for something being alive (i.e. it has to grow, reproduce, evolve, respond to stimuli, etc.) and that viruses fail several of these criteria. Here is my issue though, isn't this list arbitrary? Like, why draw the line at a place that excludes viruses. They sure alive by many standards. They even have genetic material, reproduce, and evolve. It has been proposed before that our definitions of life could exclude life on other planets that evolved differently from Earth. Doesn't that mean we are just arbitrarily choosing to exclude some from Earth itself too? Is there a reason or a benefit to exclude viruses from the tree of life? | [
"It's semantics, someone drew a line in the sand and here we are. ",
"Definitions get fuzzy in biology sometimes. There isn't a great way to determine how different two organisms need to be to be two different species, and biologist will often fall into two different camps on how to do it (called ",
"lumpers an... | [
"As a virologist, this question comes up quite a bit. To be 'alive' a few things have to be true: (1) it must maintain homeostasis, (2) it must make its energy, ie ATP, (3) it must be able to grow/divide by its own machinery. Now by their very definition viruses do not meet any of these points and as such are not c... | [
"Parasites need the conditions of a host to reproduce, they still have all the proteins and organelles needed to do so. Viruses utilize the infrastructure of the host cell (enzymes and organelles) to reproduce."
] |
[
"Has anyone in the international community confirmed the findings at CERN showing faster than light neutrinos?"
] | [
false
] | [deleted] | [
"No, it's pretty much unanimously agreed that the results are wrong, but even the people who know the experiment best can't figure out where."
] | [
"You have inherently assumed that FTL neutrinos are the same speed for all energies. The 1987 supernovae were MeV neutrinos, these are GeV neutrinos.",
"That being said much of the attention now is on the other beam-experiments to improve their timing game so they can refute this."
] | [
"Wonderfully put, iorgfeflkd. ",
"To the OP:\nWith almost every physics article you will find a discussion of the physical effect that you or your team measured and contested. In the case of the OPERA neutrino 'experiment' the paper explicitly only stated the factual findings and refused to speculate any physica... |
[
"Why does light differ from everything else?"
] | [
false
] | What caught me dumbfounded is that why is light/photons (including the visible and not visible spectrum and microwaves, radio waves etc.) the only thing that can pass through objects transparent or not(light specifically for transparent and the other waves for both transparent and opaque). I know they are like waves but a light can pass through a window while water cannot so to speak. ELI5 if you can EDIT: I know there are other things that can pass through objects aside from light BUT what I want to know is why can they while others cannot. | [
"First of all, light is not the only thing that can pass through matter. For example, neutrinos are constantly passing through even the most solid objects.",
"To understand why water can't pass through glass but light can, you have to understand electromagnetism. Matter that interacts with electromagnetism can i... | [
"On an atomic scale atoms are actually pretty far apart from eachother. The majority of matter is actually \"empty\" space. I say \"empty\" space because space is never actually empty; it is filled with particles from photons; gluons; neutrinos and other types of matter in a sea of particles.",
"However with that... | [
"there are many things that can go through a window, take for example neutrinos, they can even go through the earth without interacting with anything. "
] |
[
"How does a strong acid or base burn your skin?"
] | [
false
] | So I've tried to google this, and my bio/micro teacher doesn't have an answer for me. My money is on rapid denaturation of proteins in human cells, but all I can find from searching is "it causes a chemical burn." Thanks for any information you can provide! | [
"A strong acid is a strong dehydrating agent and what it does is take up all water from skin cells in an exothermic reaction, effectively \"burning\" them."
] | [
"And a strong base causes your fat to undergo a ",
"saponification",
" reaction changing a bit of you into soap. Very painful soap."
] | [
"this is why bases (even weaker ones) feel soapy. they free the fats that make up your cell membranes and use them, as stated above, to make soap"
] |
[
"How do meteorologists determine the chance of rain?"
] | [
false
] | [deleted] | [
"Very very very large simulations of the Earth climate integrated over millions if not billions of weather station readings. ",
"basically if you know that one point has a high barometric pressure and a nearby Point has a low barometric pressure wind will move in that direction. ",
"And then you have to predict... | [
"This is basically correct, however it's worth expanding on the importance of the fact that we're dealing with a chaotic system. Chaotic systems are, by definition, very sensitive to initial conditions. No matter how good our weather station readings (and in fact they're not that great over and within the oceans), ... | [
"Thank you. I tried to stress and chaotic point but you hit the nail on the head. As for the quoted portion I was pulling what little knowledge I have of weather physics but you are absolutely correct."
] |
[
"How is genetic information arranged across chromosomes?"
] | [
false
] | We all learn in school that (nearly) all animal cells contain DNA. We also learn that humans have 46 chromosomes, arranged in pairs. But that's where the details seem to end unless we go study this stuff on our own. Therefore, my questions: Basically I'm trying to understand why we have two kinds of DNA and how our genetic instructions are arranged. I've been studying neurology and neuroscience (you know, for fun); and it's making me start thinking about also studying gene expression. | [
"These are all great questions to be asking about DNA so I'll try to give you good answers to them.",
"In non-meiotic cells that are not actively going through the cell cycle there are exactly 46 mostly contiguous DNA molecules. Our cells are, of course, always in flux whether it be transcription, repair or new r... | [
" The mitochondrial genome exists because mitochondria were once free living microbes with their own unique genome. Over billions of years, pretty much every gene that's not ",
" necessary to perform cellular respiration (ie creating ATP from sugars) has actually ",
"migrated into our chromosomes",
". So whil... | [
"How the DNA from mitochondria physically gets into the nucleus isn’t very well understood, as the two genomes are stored in separate membrane-bound compartments inside the cell. What we think happens is that when the cell degrades messed up/unhealthy/etc mitochondria to recycle their components, ",
"stray bits o... |
[
"Will we ever be able to view exoplanets with a telescope?"
] | [
false
] | I know we currently detect exoplanets based on the wobble effect on the parent star or whether they block some of their star's light from reaching our telescopes. However, I am curious as to whether we would ever be able to "see" exoplanets with a powerful telescope. Are there any technological developments that would ever help us achieve this amazing feat? Or on a more realistic not, could we at least be able to detect the atmospheric composition of the exoplanet someday? I have high hopes for this considering that we would almost certainly never be able to see distant exoplanets within our lifetimes if we were to send a probe. | [
"It's been done"
] | [
"Aloha... I work for an observatory where we do (among other things) exoplanet hunting (naoj.org).",
"As lorgfefikd mentioned, it has been done. We routinely find new exoplanets.",
"However, our method for finding them currently revolves around watching for periodic disturbances in a stars brightness that indic... | [
"So could we theoretically view a high resolution image of an exoplanet one day that shows surface features or is this outside the realm of possibility?"
] |
[
"With regards to the \"black hole ripping apart a red dwarf\", is the red dwarf exerting any attraction/gravity thats noticeable towards the BH?"
] | [
false
] | This: | [
"It's there in the article:",
" Because the star is the lighter object, it lies further from this point and has to travel around its larger orbit at a breakneck speed of two million kilometres per hour – it is the fastest moving star ever seen in an X-ray binary system. On the other hand, the black hole orbits at... | [
"The force the black hole exerts on the red dwarf is exactly the same as the force the red dwarf exerts on the black hole.",
"Namely, Newton's law of universal gravitation is",
" = G m_1 m_2 / r",
"for the attraction force between two bodies."
] | [
"Yes the red dwarf is held together by its own gravity, but that is pretty minor compared with the gravitational field of the black hole."
] |
[
"How do we know that mass extinctions happened in the past ?"
] | [
false
] | How can we know that ? or even know how many extinctions happened ? | [
"Its easy to see in the fossil record. You can find many fossil species in one strate (lets say end of Permian) while the next one (Begining of Triasic) is very empty of species and most of the groups that you could find before have disappeared. In the case of the Permian extinction it affected 96% of marine specie... | [
"In some cases you can find the reason for the extinction too. The mass examination that killed the dinosaurs 60 million years ago was caused by a meteor. We know this for sure because some meteors contain a big amount of iridium an element that is rare in the crust of the earth. We found a thin layer of iridium in... | [
"There was another mass extinction, where we didn’t find the reason for, so scientists assume that a gamma ray storm from a super nova killed the life in that event.",
"What is the name of this theorised event?"
] |
[
"Why is it so hard to wake up from an induced coma? Example of F1 pilot Michael Schumacher"
] | [
false
] | *For those who don't know, Schumacher was skiing off-piste, he fell and hit his head on a rock, sustaining a head injury despite wearing a ski helmet. Towards the end of January, doctors at Grenoble University Hospital began trying to gradually bring Schumacher out of his induced coma but he just won't wake up.* What exactly goes on in the brain or rest of the body that prohibits one from waking up? Why is it harder to wake up the more time you continue in that coma? | [
"When someone is put into an induced coma, it's generally because they are in very dire straits. They may have severe brain swelling (likely the case with Schumacher), or they may have intractable seizures. The purpose of the coma is to make the brain calm and slow down its metabolism, so that it uses less blood,... | [
"That was very well explained, thank you.",
"Are there any drugs that can be used to aid or \"force-wake up\" the brain just like another kind of drugs are used to induce a coma?"
] | [
"Are there drugs that could be tried? Yes. Modafinil (used for narcolepsy) and amphetamine derivatives come to mind. I don't think they're ever used in this context, since it's usually the case that if someone won't wake up naturally after weaning off of the sedatives, then there's likely severe brain damage tha... |
[
"Since a focal point can theoratically be infinitely small and photons have an impulse, does this mean that we could theoratically create an \"impulse-singularity\"?"
] | [
false
] | In physics class my prof told me that a focal point can theoratically be 1-dimensional. I don't know too much about photon-impulse, but shouldn't that mean that we can focus a certain impulse on an infinitely small "area", meaning 1 point? Would this have any interesting consequences? | [
"In theory, photons have energy and they curve spacetime just like mass so a high enough density of photons can produce a black hole. Such a thing is called a kugelblitz. And again, in theory, we often assume lenses are perfect geometric objects whose focal points are 1 dimensional, so on paper your idea isn't craz... | [
"Wow, thanks for the explicit answer, that's really cool. Follow up question: Would it be possibly for \"gravitational lense\" to exist that is optimal enough to create a kugelblitz?"
] | [
"The photon density is simply too high - I don't know anywhere that this sort of thing would happen by accident. ",
"Additionally, gravitational lenses don't work in exactly the same way as a normal converging lens. If you had a spherically symmetric mass (i.e. a black hole) acting as a gravitational lens, ",
"... |
[
"What is the effect of numerous atmospheric nuclear tests on global warming?"
] | [
false
] | After watching a video on youtube about all the nuclear blasts from 1944-1998 i am curious what effect that radiation would have on global warming and/or any other short/long term effects on the planet? | [
"An nuclear explosion is impressive-looking, but ultimately the energy-content is pitiful, compared to that of the global circulation. ",
"The thermal energy from a single mature hurricane equates to a 10 megaton nuclear explosion every 20 minutes",
". The impact of a single hurricane on the global climate is... | [
"Yes, but...the energy of a 10-megaton blast is so localized that it allows some serious convective overshoot, far more than any mesoscale weather phenomenon would allow. I was under the impression that even large hurricanes are still vertically confined by the tropopause, while large mushroom clouds can pierce dee... | [
"Not much, if any. The general thought is that nuclear tests actually provided a cooling effect as the dust kicked up from the explosion reflected a lot of sunlight. ",
"This",
"\npaper actually claims is the reason for the global warming stagnation in the middle of the century.",
"Here",
" is some related ... |
[
"What inductance and resistance do I need for 500v system with 30a and power factor of 90%."
] | [
false
] | null | [
"The final inductor value will be frequency-dependent, but the system impedance can be calculated without knowing frequency.",
"PF of .9 means the phase angle is ~25.78deg. 500v@30a at the input means the system has to have an equivalent real impedance of 16.66ohm. ",
"This is all speculative as I'm working f... | [
"What are you doing? And isn't it frequency dependent as well?"
] | [
"Answering a random math question my brother asked on Facebook. i.e. nothing important"
] |
[
"What does it mean for a discovery to be \"7 sigma\"?"
] | [
false
] | According to just posted on , the Higgs boson is close to the "7 sigma" level. I know it's some sort of measure of certainty that the finding is accurate, but can someone give me a more exact definition? | [
"You are correct in that it is a measure of certainty. I'll refer you to ",
"this article",
" that gives a more detailed explanation. Essentially the \"sigma\" for an event like the discovery of a particle can be converted into the probability that the evidence for the particle arose due to random chance. Highe... | [
"Higher sigma values mean that the discovery is less and less likely to be accidentally a mistake.",
"Just want to make a clarification on that. Mistake can only mean \"random chance\". A high sigma value can not discount systematic errors, such as faulty equipment or computation that might shift a result in one ... | [
"The sigma level is the chance that the trend in the data occurs if we assume the thing we're looking for didn't exist.",
"For example, if we assume that the Higgs doesn't exist, then there's a 1 in 390 billion chance that the data we see as evidence for the Higgs occurred due to some statistical fluctuation. "
] |
[
"Why do arctic climates often have days where night is warmer than day?"
] | [
false
] | I just looked at the weather for McMurdo Station in Antarctica and Longyearbyen in Svalbard, and this upcoming week has many consecutive days where it is 3C warmer at night. How is this possible? My guess is that the sun loses much of its influence on the daily weather cycles, and that wind and sea currents become more influential. | [
"As close to the poles as these places are, “day” and “night” are rather meaningless - at McMurdo Sound it’s currently perpetual daylight and at Svalbard the sun doesn’t rise for a few months. Basically it’s weather and local topography which matter."
] | [
"Thank you!"
] | [
"Further poleward the diurnal solar cycle is less important. There are a couple of linked effects.",
"There is less solar energy overall overall so less absolute day/night difference. The sun is at lower angles so there is less incident energy per unit of surface and more attenuation due to a longer path throug... |
[
"Why is a frozen and thawed banana so much sweeter, and how does this change its nutritional value?"
] | [
false
] | null | [
"Putting together the information here",
"One of the main processes in bananas (and all fruit) ripening is the amylase dependent conversion of savoury or flavourless starches in to sugar (specifically glucose). Amylase is a common enzyme (also present in your saliva) which converts starch to sugar and is an impor... | [
"Because the cell walls are destroyed by ice crystals forming inside the cell and rupturing them. A single amylase enzyme is far smaller than a cell so it doesn't get pierced. For the same reason why you can drill a hole in a giant block of sandstone but if you try to drill loose sand the sand will get pushed out o... | [
"Fruits like banana contain water. When you freeze them, the resulting ice crystals breaking the cellular structure of the fruit. The result is that thawed fruit is mushy. Subsequently as they warm up again, a lot of the juice leaks out and you're left with less flavor. ",
"Harold McGee pointed out in his book “O... |
[
"How do cows and other large grazing mammals stay so heavily muscled when all they eat is grass?"
] | [
false
] | null | [
"Hi Hillano thank you for submitting to ",
"/r/Askscience",
".",
" Please add flair to your post. ",
"Your post will be removed permanently if flair is not added within one hour. You can flair this post by replying to this message with your flair choice. It must be an exact match to one of the followi... | [
"Biology"
] | [
"when an organism consumes another organism, it only gains 10% of it's energy. since we normally eat meat, we gain less energy. the organism only gained 10% energy from their food, so we only gain 1%. cows gain 10x more energy than us."
] |
[
"What determines the rate of action potential propagation?"
] | [
false
] | I'm going to ask what I think is the same question three times in three different ways because I can't quite pin down what I'm trying to say. Hopefully it makes sense... Assuming no myelination, what is actually responsible for mediating the change in charge along an axon during an AP? It's not the diffusion of Na+, is it? My understanding is that Na+ flows into the axon, creates a localized positive relative potential, which then activates nearby channels and repeats this process. If that's the case, then this should be slower than diffusion alone, yes? Since it's local diffusion plus the time it takes to open the next set of sodium channels? Myelination speeds signal conduction, but what is actually being conducted if there are no sodium channels to open under the sheath? None of this is instantaneous, but then what factors influence the time it takes for one node to activate the next (aside from distance?)? Na+ isn't diffusing down the covered regions of axons is it? Assuming myelination, does the influx of sodium across the membrane produce a local electric field which is then felt at the next node of Ranvier faster than diffusion alone could explain? If so, what mediates this? What is the ultimate determinant of signal propagation velocity? Thanks! | [
"The Na+ is diffusing down the covered regions of the axon. Time is saved by not having to open successive ion channels. The signal propagation velocity is limited by the diffusion rate of Na+."
] | [
"So the equation for AP propagation velocity is proportional to 1/Cm * sqrt(d/4RmRi), where Cm and Rm are capacitance and resistance of the membrane, and Ri is the resistance along the internal aspect of the axon. ",
"How is Ri calculated? Is the information regarding diffusive properties of the cytoplasm of the ... | [
"Action potentials are propagated by voltage gated Na channels, and are typically triggered at the axon hillock, where there is the spatial proximity to the axon, and density of vg Na channels to start an action potential. This is slower than diffusion, since you need to open channels, but without those channels yo... |
[
"How can you figure out the age of water? Thermohaline circulation related."
] | [
false
] | I was talking to a gentlemen from the UK a few months back, and we were talking about the age of water. He was telling me that you cannot date water unless it's pre-WWII water/post WWII water because of tritium found in water. I was trying to do some searching on how long it takes for a cycle in thermohaline circulation to take place, but can't find anything on it. I keep reading that it takes 2,000 years, but how do they know that? How do they know that the water they are drinking started as glacier melt 2,000 years ago? Thanks in advance! | [
"Ocean water incorporates atmospheric carbon, some of which has been converted to the radioactive species (C-14) through reaction of cosmic rays with nitrogen atoms in the upper atmosphere. We can thus date oceanic waters using carbon 14. Here are two summaries of the results from such work, ",
"this one",
" a... | [
"Yep, radiocarbon is the main way to get ages for the entire ocean. Of course radiocarbon has its issues, too (e.g. mixing and dispersion, incomplete equilibration with the atmosphere, etc). There are other tracers, like ",
"chlorofluorocarbons",
" (CFCs), sulfur hexafluoride, and ",
" H/",
" He dating, whi... | [
"Thank you for these responses guys. It's time to dive in and do some more reading! "
] |
[
"What's the earliest animal that plays games?"
] | [
false
] | Anyone with a cat or a dog knows animals like to play games. How about evolutionarily simpler animals? Do turtles or frogs play? What is the earliest animal that plays? Is playing an emergent trait that evolved separately in different places and times? | [
"Playing might have evolved as a way for young animals to develop motor function as well as to hone stalking/hunting skills. At least this is true for dogs and cats and other carnivorous animals. There is no way to know for sure, but it could be that it simply came about that the cubs/pups/whatever who played ended... | [
"Komodo dragons and octopuses are probably the \"earliest animals\", although we can't totally conclude that they play in the way that \"higher vertebrates\" do",
"I would suspect that some shark species also play, as well as (possibly) manta rays"
] | [
"Until more expert opinion arrives, I will continue your speculation with the fact that in order to have viable \"play\" mechanisms you need a \"play\" environment and some other bits:\n- A safe environment for the children (nest, pen, den, whatever)\n- Caring parent(s) that would help \"guarantee\" the safety\n- S... |
[
"Would a flower maintain its color in a room totally void of light?"
] | [
false
] | null | [
"Color is a psychological, not a physical property. Objects have surface reflectance properties which do not depend on whether there is or isn't light any more than their mass does."
] | [
"I thought the physical properties determined which color from the light spectrum is reflected. So a total absence of light would mean no color is being reflected from the object, but the object is still there. I could be misunderstanding. "
] | [
"Physical properties of the object determine which ",
" of light get reflected. The visual system is what determines how those wavelengths are experienced. Different combinations if wavelengths can produce the same color experiences. Some wavelengths produce no color experiences whatsoever (e.g. infrared). It is ... |
[
"Why is blood group O+ so common?"
] | [
false
] | Would it not be a rare blood type as the allele for blood group O (I is recessive to the other alleles? | [
"Whether an allele (type of gene) is dominant or recessive, doesn't really determine if it is common or not. Just think of an island of mostly red-heads and a couple brunettes. If mating isn't biased by hair color, the number of red hair alleles and the number of brunette alleles wont change. In fact if a number of... | [
"Just because it's recessive doesn't mean it is less common. Given enough time it can become an overwhelming majority. The gene for 5 fingers and toes is recessive but just about everyone I know has five of each "
] | [
"Genetic testing, assuming we know where the relevant genes are.",
"Look back further: Are any of your grandparents or other relatives type O? This doesn't guarantee anything (eg. one grandparent could be OO, your parent AO, and you AA), but it might give some idea. ",
"Have a bunch of kids with someone with ty... |
[
"Why does left handedness only make up approximately 10% of the population? Is there a reason for such an unequal distribution?"
] | [
false
] | [deleted] | [
"Although there appears to be a hereditary component to determining handedness, like most traits it does ",
" follow simple Mendelian inheritance. There is no \"left handed gene\"."
] | [
"I had to read this a few times but ",
"2 right-handed parents usually have RH kids because of the dominant gene, but because of that square(you know with genes on different sides) you can sometimes have a lefty.",
"Why does that mean two left handed parents have no chance of a righty?"
] | [
"If the left handed gene is recessive, you would need two left handed genes to be left handed. For two left handed parents, where would the child get a right hand gene?",
"Edit: It seems that ",
"handedness",
" is not completely genetic. ",
"Also here",
"."
] |
[
"Is it possible for animals to have mental disorders?"
] | [
false
] | If so, are human mental disorders common in animals (A dog with schizophrenia)? Are there unique disorders specific to animals? | [
"Although there are certainly objective physical changes in some disorders, much of what we deem psychiatric disorders are based on subjective states--the person ",
" depressed, the person is hearing voices, etc. Since we can't ask animals how they feel, we can't know much about the subjective internal states of ... | [
"Most animals probably can. We are animals, so what's to say other animals can't get them? Although, the types of disorders would probably differ."
] | [
"I'm sure they do, nature isn't perfect, there's lots of room for error and error does happen. The thing is though, in the wild, say in a heard of bison. The animals with a mental disorder (depending on severity) would probably die off a lot quicker and humans wouldn't have as good of a chance to find and test thes... |
[
"Morals and ethics aside, could a developed nation feasibly develop and grow their own army of cloned humans/soldiers with our current technology?"
] | [
false
] | null | [
"We don't have artificial wombs so there will always be a birth mother and biological father. They're still going to be little kids who have to grow up and get an education. Either way, you're going to have to sequester a bunch of women as brood mares and steal their infants; whetehr or not those infants are all ... | [
"Doesn't africa already have this? When roving militias invade a village, kill all the men, rape and disfigure all the women, and steal all the children for military training? (then make it a point to come back 10 years later to see what the women of the past have grown / produced) You then have an army of young bo... | [
"http://www.youtube.com/watch?v=kcUvSeEm7fc",
"This could potentially answer your question. "
] |
[
"What exactly does it mean that a vaccine/booster etc is X% effective?"
] | [
false
] | null | [
"Typically they are referring to “Relative risk reduction”. Take 100 people and give them vaccine, 100 people who don’t get it (or better, get a placebo). After some period of time, see how many in each group got the virus.",
"Let’s say 2 in the treatment group got the ‘vid and 20 in the placebo group.",
"... | [
"This obviously gets a lot more complicated if you want - anyone who has ever taken an epidemiology class knows exactly what I’m talking about. Just a few questions to show how complicated this can get:",
"How are we defining who got disease? Are we looking at symptomatic people who got tested? Are we looking at... | [
"Gotcha. All this makes perfect sense to me. I guess a lot of what that number means depends on the parameters/definitions employed by the particular study. Sometimes I feel like certain study designs should be formalized if they're useful enough, but that also would lead to limitations/controversies over what the ... |
[
"Do insects sleep? Do they dream?"
] | [
false
] | [deleted] | [
"Wikipedia",
" suggests that insects exhibit sleep-like behavior.",
"Unfortunately, since their behavior is so simple, it is difficult to tell exactly what is sleeping. The studies Wikipedia describes base their conclusions on the fact that sleep-deprivation causes the insects to lose cognitive ability.",
"I ... | [
"Insects have a state called tropor. So yes they do 'sleep'.",
"\nAs for dreaming, i guess you could set up a test an see if conditioning goes faster if the insect is put in tropor after it.",
"Hard to test actual b rain activty on that sdale"
] | [
"Can you explain what tropor is?"
] |
[
"What's the difference between two experiments using laser emitters and slits, one of which demonstrates \"quantum physics\" behavior and the one showing diffraction? Is diffraction involved in the quantum one or is it unrelated?"
] | [
false
] | I have a big question and a minor question about experiment(s?) involving shining light through narrow slits. I've seen descriptions and videos of the double slit and how it's "quantum mechanics". I also did an experiments in high school physics to demonstrate diffraction using a laser emitter and a slit that was similar. It was a while ago so I don't remember all the details. But you achieve the "venetian blind" pattern because the waves cancel each other out in dark spots and amplify in the bright spots. My first question is: What are the differences between the diffraction experiment and the quantum physics one? From what I can remember they seem to be the same experiment, but I doubt that's the case. Second question: In the quantum experiment, I remember reading about "when the light was being observed it converges into two slits", and something about how when the data collected was set to automatically be erased (so it was still collected, but then discarded), it... did something, but I can't remember how it affected the results. Anyone know? | [
"There aren't any, that's the point! One involves light and the other involves a stream electrons (or any other particles) aimed at the slits. The fact that they both result in a diffraction pattern demonstrates that it's not just light that has wave-like properties, but matter too! i.e. the wave-particle duality"
... | [
"Yes, this is exactly it. The quantum physics version uses electrons instead of light, and it demonstrates quantum mechanical properties because ",
" In other words, the diffraction thing is part of the quantum mechanics thing."
] | [
"The way I learned on how to imagine how this happens is by doing a thought experiment for a second and picture this. ",
"You are in a bath tub and you have a piece of plastic that has 2 lines in it. You drop one drop of water creating one wave with the drop. The wave expands in all directions evenly and when the... |
[
"Why can animals like honey badgers eat snakes that are extremely venomous, whole, and not die/get sick?"
] | [
false
] | [deleted] | [
"Venemous =/= poisonous. ",
"Venom is injected, whereas poison can be ingested/absorbed etc. So by eating the animal, the honey badger swallows the venom sacs or whatever the venom is in and it is processed, diluted, broken down or excreted like all other food. ",
"The venom of a snake would be dangerous to it ... | [
"Yes, as far as I know, ",
"most venoms can be ingested by humans without harm",
". The human digestive system does an excellent job of breaking down the proteins that compose venom into relatively harmless amino acids. ",
"Venom is most harmful if it is injected into the bloodstream or comes into contact w... | [
"So by eating the animal, the honey badger swallows the venom sacs or whatever the venom is in and it is processed, diluted, broken down or excreted like all other food.",
"Are there snakes for which this is also true in humans?"
] |
[
"Does the orbit of an artificial satellite at the equator tilt with the earth's seasonal tilting?"
] | [
false
] | [deleted] | [
"The Earth's tilt axis doesn't actually change throughout the seasons. Instead, the direction of the tilt ",
" changes.",
"Imagine you're walking around a table, but you always face north - so at one point, you face towards the table, but halfway round you're then facing away from the table. It's a similar idea... | [
"Yup. If you're having trouble picturing that, ",
"see this picture",
"."
] | [
"Typical, the one time I don't bother to look for an image, there's one which shows ",
" the point I'm trying to make."
] |
[
"How do electromagnets work?"
] | [
false
] | null | [
"Electric currents produce magnetic fields. If you have an electric current traveling through a resistive medium, there are energy losses to heat. If the resistance of the medium is zero, like in a superconductor, there are no losses to heating."
] | [
"Any electric current produces a magnetic field."
] | [
"Any electric current produces a magnetic field."
] |
[
"Why are surgical leg amputations done either above the knee or below the knee but not right through the joint itself?"
] | [
false
] | Why not just separate the joint and take the tib-fib portion? | [
"I think the question relates to why not leave the end of the bone as the termination point - that is to say why not simply remove the tibia, fibula and patella, leaving the smooth articulating surface of the femur as the termination point."
] | [
"The kneecap is a bone, the patella, specifically. Are you suggesting we leave a portion of that bone behind?",
"This would be incredibly complicated and dangerous to a patient as well as making a smooth fitting and operating prosthesis replacement near impossible.",
"Check out a good anatomical image of the "... | [
"We do this, it's a transfemoral prosthesis.",
"I'm not sure what he means, because he said above/below the knee.",
"Above is transfemoral, below the knees is transtibial."
] |
[
"Age of the Galaxy"
] | [
false
] | So, the recent article about the discovery of the oldest spiral galaxy got me wondering how old our own Milky Way is. A quick google and I find that the internet gives an answer of around 13 billion years - almost as old as the universe itself and more than 2 billion years older than the newly discovered ancient spiral galaxy. Seeing as our own galaxy is spiral, what is going on here? | [
"The discovery isn't of the oldest spiral galaxy thought to exist, it's the oldest spiral galaxy we've ever taken a picture of.",
"Because light takes time to go through space, the light we're receiving from the galaxy is that old. All galaxy are effectively the same age.",
"The discovery is of a galaxy that i... | [
"I suppose it comes down to your definition of galaxy - I think what I was really driving at with this question is: what is the nature of a galactic life cycle? \nAll other galaxies that we observe from as long ago as the one the article, at least that we know of, are crude, shapeless lumps. So, if the crude shapel... | [
"I suppose it comes down to your definition of galaxy - I think what I was really driving at with this question is: what is the nature of a galactic life cycle? ",
"Loooooooooong, of course, but other than that, a lot of this question can be best answered ",
"here",
".",
"So, if the crude shapeless lump tha... |
[
"Why aren't all mammals omnivores? Is there a benefit on being able to eat nothing but plant/meat compared to being able to eat both like humans are?"
] | [
false
] | While herbivores have a more easier access to food than carnivores, they are more susceptible to droughts and changes in the environment than carnivores are. While carnivores do not need to eat as often, they have to use more energy to catch and kill their prey which can be a more riskier lifestyle than grazing in a field. Is there any evolutionary benefit on being a carnivore like a cat, a herbivore like a cow than an omnivore like a human or a goat? Are omnivores in general any better at surviving times of famine than carnivores or herbivores? | [
"why aren't all mammals omnivores?",
"So, let's start here. Mammalian diets are more flexible than the boxes \"omnivore\", \"carnivore\" would indicate. ",
"Here",
" is a great example of an herbivore engaging in predation. Certainly not common, and animals will be a very small minority of their diet, but not... | [
"So how do humans fit in? Are we specialized in a trait, or generalized? In any event, we've been successful."
] | [
"I would categorize humans as very generalized and flexible in digestive tract/teeth, with a very specialized nervous system and limb arrangement that allows for a very broad range of behavior and interaction with the world. ",
"Overall, I would say that our digestive and hunting capabilities match our intellect;... |
[
"Can other animals get allergies as well?"
] | [
false
] | [deleted] | [
"There are cases of dogs testing positive for allergies to cats. Many domestic dogs are tested and treated for allergies. Dogs can get allergy shots just like humans or can be treated with Benadryl (and I believe other allergy meds as well). ",
"Dogs can also have anaphylactic allergic reactions to things like be... | [
"Absolutely. An allergy is just a particular type of immune response. Humans do have an unusually high rate of allergic response but its because a) we're one of the only species that regularly eats foods processed with other foods, thus contaminating them with other allergens and b) many people are raised in relati... | [
"Dogs are frequently allergic to grass (it gives them contact dermatitis, just like in people). It's not uncommon for dogs to become allergic to pollen. They're get itchy watery noses/eyes and it's treated with Benadryl if it's short term, and Claratin long term, just like in humans. ",
"Cats and dogs are frequen... |
[
"Do plants need \"rest\"?"
] | [
false
] | Can plants go through photosynthesis nonstop without a break? Or do they need some time to slow down? EDIT: Let me rephrase, if a plant is given light 24/7, watered when needed, and new/changed soil when required, would it work itself to death? | [
"In general, most plants have increased photosynthesis rates during the day and decreased or no photosynthesis during the nights. This is simply because there is light during the day which is necessary for the light dependent reactions of photosynthesis (the light independent reactions of photosynthesis do not requ... | [
"Lots of growers give their cannabis plants 24hours of light during the vegetative period. No ill effects."
] | [
"This isn't 100% related, but: chloroplasts (the light capturing organelles that contain chlorophyll) relocate themselves according to light intensity. During the peak sunlight hours, a plant may need to protect its chloroplasts from damage, so the organelles will line up behind one another and \"hide\" from the su... |
[
"Help me figure out a weird sky phenomenon I saw this morning."
] | [
false
] | I'm an early riser, so even on my days off I'm up at 6. I was outside just before 7 am - the sun wasn't up yet. I hopped in my car to drive to the store for some coffee, donuts, and (you guessed it) bacon. I pulled out of my driveway and drove west. I live in a valley and so I was looking at mountains; beyond those mountains is the Pacific Ocean. The Sun was not quite up yet, still tucked behind the mountains to the east. The sky was quite clear, one or two high fluffies here and there and a little mistiness along the horizon to the north and west. Here is what I saw: in the western sky extending from the tops of the mountains to about a third of the way through the sky was a column of shadow. That's the best way to explain it - the sky was bright (the sun was almost up) except for this one column which was considerably darker. It was like a reverse searchlight was mounted behind the mountains to the west. The "sides" of the column, then, were not parallel to each other, but instead spread out slightly. The sides, though, did seem to be true - they weren't wavy and did not bend (except to follow the arc of the sky). I drove to the store, looked at it from the parking lot, went inside to shop. When I came back out, the column was still there. It was not as dark and not as focused. I'm not sure about this, but it also seemed to have changed its angle in the sky - where before it was coming roughly straight up from behind the mountains, it now seemed to be tilted slightly to the south. This may have been an illusion based on the fact that it's really hard to judge angles across a spotlessly clear sky in the daytime. It was gone by the time I got home - maybe 15 minutes total from the time I noticed it. Here's what it wasn't - the shadow of a jet contrail. That was my first guess, but jets do not travel that direction in my neck of the woods. There is nothing to the west except for the ocean, and it's kinda big. Jets travel north/south or variations thereof (northwest/southeast, etc.) I also should mention that one of the clouds in the sky looked a bit like the FSM. Perhaps the shadow column was one of His Noodly Appendages? I forgot to buy bacon. | [
"I couldn't exactly paint a mental picture of what you are describing here (maybe I need an ms paint pic to help sort it out), but one possibility may be ",
"Anticrepuscular rays",
", shadows of clouds beyond the horizon being cast upwards instead of the normal case, downwards. A good site with an overview of v... | [
"It looked like anti-crepuscular rays except there was only one of them, and instead of emanating from the area near the sun, they came from the opposite side - the sun was rising (in the east, of course) and the \"pillar of shadow\" was in the west. "
] | [
"This is an anticrepuscular ray. Where crepuscular rays merge at the point that the sun is, anticrepuscular rays merge opposite the sun. ",
"From what you say here, this suggests that the sun was shining in the upper atmosphere, and not on the ground, thus how you were able to see the shadow. If there was just on... |
[
"What would happen if Antarctica melted instantaneously?"
] | [
false
] | This question came up because I was experimenting with and put a nuke on Antarctica because I was bored. Would the water displace equally in all directions? Or would currents,etc have anything affect on this displacement. Would the entire world flood water world style? How quickly would it happen(if it happened)? | [
"Global average sea level rise would be 60-70 meters. I don't remember the exact number, but that's okay because the exact number isn't known anyway. Large parts of Antarctica remain unexplored, without ice thickness measurements.",
"However, the sea level rise would not be uniform worldwide. The biggest effec... | [
"Here's an interactive map of the effects",
". Set for +60 m."
] | [
"Small? ",
"http://www.neatorama.com/2009/11/09/how-big-is-antarctica/"
] |
[
"Does charging your phone slower, by connecting it to a pc by usb-a, makes the battery last longer than connecting directly into a outlet?"
] | [
false
] | null | [
"This is no longer correct with the new charging methods, like \"Quick Charge\" that boost the current and the voltage substantially. Normally USB 2 would be at 5V at 2.5 Watts, Quick Charge is up to 18 Watts.",
"This will boost the charging Voltage to up to 20V. This allows you to very rapidly charge your phon... | [
"This is no longer correct with the new charging methods, like \"Quick Charge\" that boost the current and the voltage substantially. Normally USB 2 would be at 5V at 2.5 Watts, Quick Charge is up to 18 Watts.",
"This will boost the charging Voltage to up to 20V. This allows you to very rapidly charge your phon... | [
"The low and slow methods are less stressful on the battery because the heating is related to the square of the power (P=I",
"*R) and some will overheat until you don't really want to hold it in your hand or shutdown entirely. Thermal expansion and contraction flex a battery that doesn't want to be flexed, but mo... |
[
"Are there chemical elements that no longer exist? Could we continue to create man-made elements past what we've already made?"
] | [
false
] | null | [
"The big bang created almost nothing besides Hydrogen and Helium. The reasons for this are complicated, but basically boil down to all the fusion pathways from Helium to heavier elements take a long time, and Big Bang Nucleosynthesis was only occurring for a few ",
".",
"Every element found in nature that is he... | [
"I can say that, because the formative methods are different. ",
"Superheavy elements made in supernovae are created by extremely rapid sequences of neutron capture/beta decay, and the upper limit to elements that can be created by this method is listed in the source I linked above.",
"Superheavy elements beyon... | [
"I can say that, because the formative methods are different. ",
"Superheavy elements made in supernovae are created by extremely rapid sequences of neutron capture/beta decay, and the upper limit to elements that can be created by this method is listed in the source I linked above.",
"Superheavy elements beyon... |
[
"Why would our sense of smell become selected to be worse than what we had before? (Evolution)"
] | [
false
] | null | [
"It's not that it was a disadvantage to have a strong sense of smell, but that this was no longer an important trait. Individuals were just as likely to survive long enough to reproduce regardless of how well they smelled."
] | [
"Very good question. You're thinking about the root of the issue so that is an excellent start. Evolution in simple terms is about keeping some things and getting rid of others based on what you need now. Consider evolution as learning to ride a bike. When you start out, you're riding in the day time and you ne... | [
"Everything becomes worse if it's ",
" selected for. There's no need to select for non-function to lose function, random mutation can take care of that very easily. More than half of our potential olfactory receptors simply aren't expressed or have frame shift mutations rendering them useless, but this doesn't me... |
[
"If the cyclin/cyclin-dependent kinase inhibitor p21/WAF1/CIP1 were to be silenced in humans, could its absence help reduce the chance of breast cancer?"
] | [
false
] | So basically, we have what's called the BAF180 ( a subunit of the PBAF chromatin complex) which, when mutated, binds to the p21 gene and arrests the G1 phase of the cell cycle. The p21 gene apoptosis and does not under any circumstances induce cell death. In breast cancer, the PB1, which encodes BAF180, is found to be mutated. While I know that cancer is caused by multiple mutations, there is still a chance to significantly reduce the risk if a method to silence the p21 gene were to be implemented. What does Reddit think? | [
"This Google Scholar search",
" may be a good place to look for relevant journal articles.",
"A few look promising, such as this one ",
"\"Linkage of Curcumin-Induced Cell Cycle Arrest and Apoptosis by Cyclin-Dependent Kinase Inhibitor p21/WAF1/CIP1\"",
"And this one ",
"\"Cyclin-Dependent Kinase Pathways... | [
"We have to be very careful with p21. Remember, even though it is reported to have oncogenic activity, it is classically thought of as a tumor suppressor (though arguably an atypical one). p21 is in the middle of a very delicate axis of cell control and feeds not only into apoptosis and senescence but also DNA repa... | [
"Thanks for the response. I've been working on my abstract for a while now, just thinking.",
"Edit: Spelling"
] |
[
"While earthquakes are considered a natural disaster now, were they a big deal back when we were just hunters and gatherers?"
] | [
false
] | Thinking about it, the only reason earthquakes are destructive to us now is because of the sheer amount of buildings we have built everywhere. There's also the tsunami afterwards but ancient people away from the coastline shouldn't have problems even with the strongest of earthquakes. Am I missing something here, or are they just not as big of a deal before than it is now? | [
"Our built environment along with population density in earthquake prone places certainly does increase the hazard posed by earthquakes, and in detail the majority of damage and death in earthquakes are at least in part related to buildings (e.g., ",
"Doocy et al, 2013",
"). In the absence of buildings, the ear... | [
"They were a very big deal. For one thing, they were not understood so a great deal of effort was expending creating stories about their god and why their gods destroyed everything, trying to make the incomprehensible comprehensible.",
"Especially in coastal areas, where hunter gatherers congregated, earthquake a... | [
"Thanks for the link to the video.Very interesting."
] |
[
"How can a \"point\" particle exist if we, as macroscopic beings, have volume?"
] | [
false
] | We cannot be simply composed of INFINITE point particles, can we? There has to be a limit. | [
"Yes, we are composed of finitely many point particles. Roughly 10",
" or so."
] | [
"When we experience something in the macroscopic world as being solid and taking up space, what we're really experiencing is something that light and/or objects can't pass through. As an example, a chain link fence appears like a solid sheet to a soccer ball, even though there's lots of room between the links. To a... | [
"If you accept the idea of being composed of finitely many point particles, then you have to admit that we are unconnected and thus have no volume.",
"Topologically, since we are the set of finitely many points this means we closed (we have no limit points, thus the set of points we are made up of contains all ou... |
[
"Why do digital cameras have real shutters? Can't they turn on and off the sensor electronically?"
] | [
false
] | I'd imagine that it'd be quicker to do things electronically, avoiding the hassles of a physical object opening and closing. | [
"A lot of point and shoot cameras ",
" have an electronic shutter. There are pros and cons to both devices. A mechanical shutter lets the manufacturer use a simpler and more efficient sensor (lacking the electronics needed to turn it of and on) with a higher fill factor.",
"From ",
"http://www.steves-digicams... | [
"To understand the answer to this fully, it would be helpful to understand how digital sensors work. Most cameras these days use CMOS sensors, but the somewhat outdated CCD sensor is a bit easier to understand. \nFrom a report I did on CCD sensors: \n\"CCD sensors are a type of charge transfer devices. The actual d... | [
"One aspect is that image quality is higher if the sensor is kept cool and dark. Noise levels increase if the sensor gets warm."
] |
[
"Why isnt Planck length a base unit?"
] | [
false
] | [deleted] | [
"G is a very poorly known constant, being very hard to measure. This makes it, and all derived constants, very unpractical units.",
"By contrast, before using the speed of light to define the metre, we had independent definitions based on more... down to Earth phenomena and the value of c in old meters per second... | [
"TL-DR: the Plank length is actually derived from the gravitational constant (G), speed of light, and Planck constant. It does not have an exact (known) value. "
] | [
"all dimensionful fundamental constants are no different. The difference between c and l_P is just the accuracy to which the ratio with the corresponding SI unit is known."
] |
[
"We've had an magnum opus of a thread about the speed of light, but I feel like I could use one about evolution and abiogenesis. Can anyone help explain to us how it all happened?"
] | [
false
] | I know that the two are separate things, but they get confused a lot, and I think it would be nifty If we had a thread like one to help clear everything up. Also, how did life come into existence and what were the mechanics behind primitive nucleotides turning into humans and flowers? | [
"Abiogenesis is incredibly difficult to study for several reasons. First, all of the evidence was sub-microscopic, on the scale of chemicals less complex than ordinary proteins. Even if any remnants from pre-cellular life still existed from then (keeping in mind that such stuff would serve as food for many living o... | [
"Look up the Miller-Urey experiment. Basically, the researchers proposed one explanation of how life arose by recreating the primordial environment.",
"They put inorganic compounds common at the time (water, methane, ammonia, and hydrogen) in a flask and fired a quick spark into it to simulate lightning hitting i... | [
"i believe the point of the miller urey experiment's findings and their significance was not that life could arise from those specific conditions, but that life could arise from ",
" condition that was at least somewhat similar to the one in the experiment. it was more of a proof of concept than a perfect model."... |
[
"Would rum cake show up positive on an alcohol test?"
] | [
false
] | [deleted] | [
"Except in most rum cakes, you put the rum on the cake after it's baked."
] | [
"It is certainly possible. A rum cake is basically a sponge cake soaked in rum, so it still has alcohol in it (i.e. none of it has baked out). Therefore, if you eat enough of the cake it can conceivably get you drunk. You would have to eat a lot of the cake to actually feel anything, and I'm not sure about what the... | [
"Actually this doesn't happen as much as people think! In fact, to completely get rid of the alcohol you would have to cook the food item for over 3 hours.",
"Cooking for 15 minutes leaves 40% of the alcohol, one hour leaves 25% of the alcohol. A very significant number.",
"Source: Augustin, Alcohol Retention i... |
[
"Conceptually, how does the speed of light relate to the permeability/permittivity of free space?"
] | [
false
] | I know the equation that relates the three constants: c=(ε0*µ0) However, I never understood why this worked or if there was a conceptual reasoning behind it, so any explanation would be greatly appreciated. | [
"Light can be described as an electromagnetic wave. Electromagnetism is described by Maxwell equations. When you work out those, you end up with the equation of wave motion for light, with speed value equal to c as you described.",
"This by the way prompted a crisis: that speed value is the same regardless of the... | [
"The idea behind the permittivity and the permeability of free space is to represent empty space as a material. In gaussian units, for example, they don't appear. They only enter the picture when one describes electromagnetic fields in matter.",
"Once the analogy is done, and one treats empty space as if it were ... | [
"https://newt.phys.unsw.edu.au/einsteinlight/jw/module3_Maxwell.htm",
"There's the derivation of how c is calculated and what it comes from, hope that helps!"
] |
[
"If two small moons or planets collide together in space, over time they can essentially create one big moon or planet. My question is, by that logic, shouldn't our own moon be getting closer and closer to us, instead of further away each year?"
] | [
false
] | I'm not sure if I worded my question good enough in the title for others to understand so I'll try to go more in depth here. Just tonight, I saw a simulation on what it would be like if two planets collided together. The result was chaotic. Over time the debris from the two masses, through gravity, were able to come together and create a larger mass. I've also seen this being talked about by the likes of Neil deGrasse Tyson and other big name astronomers on the science channel. But going by that logic, shouldn't our moon be getting closer to us instead of further away? As in one day our moon should collide into the earth effectively making the two masses into one mass that is slightly larger than Earth? I appreciate any feedback. Thank you. | [
"I don't see the logic that because some things that crash melt together, nothing can move away from eachother..... Why would our moon have to be moving inwards?"
] | [
"If two small moons or planets collide together in space",
"You said it: \"if\". The answer is that they don't always collide.",
"In the simulation that is currently in the front page of ",
"/r/space",
" (",
"gif",
" - ",
"comments section of the thread",
") most of the debris ejected gets into very... | [
"going by that logic, shouldn't our moon be getting closer to us instead of further away?",
"No. Just because something can happen does not mean that the circumstances that lead to it are currently happening. That's like saying that because eating a bunch of Snickers makes me fat, I should be getting fatter. "
] |
[
"Is it possible for a person to be colorblind in only one eye?"
] | [
false
] | Something like the heterochromia mutation? | [
"Heterochromia is the result of more or less pigment in the iris of one eye. While there is usually a genetic component, there are a whole collection of genes that interact with each other and the environment to regulate melanin production. So it's a lot easier for a mistake to happen.",
"Color blindness is more ... | [
"Could we argue that a random mutation during embryo/fetal develop could allow for colorblindness in just one of the eyes? At the stage where a single cell mutating would affect the entire eye, but only one. Admittedly, this is also very low, but probably lower than your example. Maybe. "
] | [
"That's also a plausible way it could happen and one I didn't consider.",
"But the odds of either scenario are so minuscule that it's really hard for me to make a guess at which one is less likely."
] |
[
"Can you become resilient to 3D?"
] | [
false
] | [deleted] | [
"It is after all, only an optical illusion.",
"It actually functions in the same way that gives us 3-D vision, it displays a separate image for each eye. "
] | [
"depth perception operates through the brain processing two images that are slightly apart from each other, with 3d movies and games the two images are created artificially either by alternating images or using polarised light, both of which require special glasses. ",
"However I have noticed that with 3d heavy m... | [
"It's an optical illusion as much as your regular vision is. The only difference is that it has a finite resolution.",
"You're probably just more used to it. It's not that you've \"become resilient,\" the quality is the same, there's just less awe involved."
] |
[
"Is the Mars curiosity rover waterproof?"
] | [
false
] | null | [
"The sealant to keep out environmental dust is as good as the sealant to keep out water. Electronic components are also in a sealed environment to facilitate temperature control. ",
"The rover probably isn't balanced with respect to buoyancy, so wouldn't function as intended underwater (let alone the instrumentat... | [
"The sealant to keep out environmental dust is as good as the sealant to keep out water. Electronic components are also in a sealed environment to facilitate temperature control. ",
"The rover probably isn't balanced with respect to buoyancy, so wouldn't function as intended underwater (let alone the instrumentat... | [
"This is sort of besides the point; it's like me saying 'This is heat resistant!' and you saying 'Yes, but can it survive being submerged IN LAVA?!'",
"The sealants the Rover has are for an environment that is approximately 70-150 millibars. There's probably a good deal of redundancy in place, and remember, the t... |
[
"What are the differences between a cold dead star and a planet?"
] | [
false
] | [deleted] | [
"A black dwarf is a stellar remnant of any star not massive enough to become a neutron star. Actually, a white dwarf is what I just described, but as a white dwarf cools over time, it will become a black dwarf. It's thought that no black dwarfs exist yet, as it takes longer than the age of the universe to cool from... | [
"It's not just the limit of detectability - that's the temperature of the oldest white dwarfs as well. 10",
" is the time it takes for a white dwarf to cool based on estimates that ignore the possible existence of WIMPs. If that assumption of particle physics is wrong, the length of time can increase by a factor ... | [
"So, here it really depends what you call a 'cold dead star'.",
"There are things called ",
" that are small stars with about 0.08 solar masses (about 80 jupiter masses) that can only really liberate energy by gravitational collase. Incidentally, this mechanism is the reason that Jupiter is so 'hot' - the energ... |
[
"How does LIGO relate to relativity?"
] | [
false
] | null | [
"Gravitational waves are a prediction of general relativity."
] | [
"So this form of information transfer is very interesting. Does the acceleration of any matter result in gravitational waves as the curvature of surrounding space is modified"
] | [
"Gravitational waves are only produced if the matter distribution has a changing mass quadrupole moment (it needs to have a nonzero third time derivative). So something like two black holes orbiting around their common center of mass will emit gravitational waves."
] |
[
"If a salmon's birth stream/river was filled in, what would they do?"
] | [
false
] | Salmon go back to their birth stream to reproduce, right? What would they do if a dam or natural formation blocked off their access to the stream? Would they go somewhere else, reproduce at the closest point, do nothing and die, or what? | [
"They would most likely hand around the base of said obstruction until either they die from starvation, spawn at the point they were stopped or leave.",
"I am guessing a mixture of the first two. However being semelparous (die after one large spawning event), even if they were to spawn the adult population would ... | [
"IIRC they die trying to go back. "
] | [
"How? do they beach themselves where the former mouth of the river was? or something else?"
] |
[
"The soil triangle: Is there a name for charts of this type?"
] | [
false
] | null | [
"I am not going to release this question, but I will tell you that it is called a \"ternary diagram\" or \"ternary plot\"",
"It is commonly used in many fields, such as geology, materials science, chemistry, and more",
"https://en.wikipedia.org/wiki/Ternary_plot"
] | [
"Great, thank you very much for answering my question! I had trouble googling it because every query inevitably returned a myriad of geology-related results and no results about charts proper."
] | [
"haha! I understand. The only reason why I know the answer is because of my degree in materials science."
] |
[
"What happens when lightning hits a beach of sand?"
] | [
false
] | [deleted] | [
"They're called ",
"fulgurites",
".",
"Cool, huh?"
] | [
"You get a piece of fulgurite if you're lucky.",
"http://en.wikipedia.org/wiki/Fulgurite"
] | [
"On a related note, a saw a beautiful 20 foot high fulgurite on display at the local science museum a while ago. If you are interested in this sort of thing, drop by a science museum or natural history museum and take a look around."
] |
[
"Massive black holes can spew out huge amounts of energetic material. Would this process convert heavy elements back into hydrogen and helium?"
] | [
false
] | null | [
"For example, if a nickle-iron planetary core is ripped apart, is it converted into protons and other light nuclei?",
"For example, if a nickle-iron planetary core is ripped apart, is it converted into protons and other light nuclei?"
] | [
"For example, if a nickle-iron planetary core is ripped apart, is it converted into protons and other light nuclei?",
"The core would get ripped apart long before it got close due to the Roche Limit dynamics.",
"The required tidal forces to rip an atom apart are likely only encountered inside the event horizon ... | [
"The material itself doesn't enter the black hole at any time it is merely accelerated and ejected in massive jets at Hugh energies. The forces at work in this are likely not enough to overcome nuclear bonds (although perhaps it could effect some very heavy, unstable elements) and so the actually element would not ... |
[
"How can a car battery be rechargeable if the voltage is produced by a chemical process?"
] | [
false
] | As far as I understand, lead and lead oxide are suspended and diluted in sulfuric acid. If this is the case, how can a battery 'die' if left charging something overnight, and how can a jump bring it back to life? I'd think that if the battery died, it'd be dead forever as there is no more chemical reaction taking place? | [
"Charging a battery undoes the chemical reaction. You put in energy to put it back to the high-energy state.",
"The full chemical equations are spelled out on the ",
"wikipedia page",
".",
"This is also true in lithium-ion batteries. When you discharge the battery, the lithium ions move from negative electr... | [
"Discharging a battery requires the motion of ions inside of it. The motion of ions creates an electron current from one battery terminal to another. So, if the terminals are not connected at all then there is zero current and thus no ions are moving.",
"This process is reversible. So pushing a current through th... | [
"Thanks for your response, that makes sense. "
] |
[
"Is Magma the Same?"
] | [
false
] | Is all magma the same? for example if you have a piece of shale and it melts into molten rock (magma), would the magma be the same magma as molten marble? Or would the magma be made of a different combination of materials. | [
"No. The chemical compositions of your two hypothetical melts would be different and thus the physical properties would be different.",
"This is more easily discussed in terms of more realistic magma/lava types that we see regularly. In considering types of magma, we usually think of them in terms of what types o... | [
"Living in Hawaii, I am amazed at how different \"lava\" can be in different places, even though it is the result of the \"same\" hotspot. How well mixed is the magma beneath the earth's crust? I would have expected it to be well mixed, but it seems that it is not."
] | [
"Can you explain a little more about what you mean about different lavas? do you mean surface structural expression? or chemical composition?"
] |
[
"Can other sources of light be concentrated through a magnifying glass to start a fire? Like the light from a flashlight, or from a full moon?"
] | [
false
] | null | [
"You can only focus light to reach the temperature of the light source.",
"That is only true for thermal emission, not for light sources like LEDs (e.g. in a flashlight)."
] | [
"In the 1960's there was a company called Aerometerics. They made a line of products that were basically quartz/halogen lamps in reflectors. The focused light intensity was high enough that these were used to braze metal, heat treat steel, and could even melt through a steel sheet if left long enough on a spot. The... | [
"Yes you can do this, most laser used for cutting work like this. Something emits light then it is highly focused to heat the material to very high temperatures. An object in general can only get as hot as the thing that is heating up if both are acting like perfect black bodies. This is because when something is h... |
[
"What effects did the weight and size of a dinosaur have on the type of environment it needed to support it?"
] | [
false
] | I am not 100% sure I used the right flair, if another would be more appropriate, please change it! I used to drive semi trucks, and one of our major rules was never leave a loaded trailer on anything but concrete, because it's supports would sink into the ground on anything else. In addition to that, I play and watch a number of scifi mecha type games, movies, and anime, and the discussion always comes up how mecha are unfeasible especially when they get big, because the ground wouldn't support their weight focused on where their feet were. That had me wondering if the huge multi-ton dinosaurs had similar problems. I am interested in hearing anything about how their mass/size/weight effected them. | [
"Wow - this is a very cool question. I'm a geotechnical engineer, so I'm going to come at this from that perspective. A quick apology to most of the world, I'm going to do this in US Engineering units. I'll provide a couple conversions as I go. ",
"From a quick look at ",
"Wikipedia",
", it appears one of the... | [
"Before maybe 50 years ago it was believed that sauropods would have to live in water to support their weight, but the idea has been rejected, because they show no adaptations to such a lifestyle and the upright stance is best suited to moving overland. Spinosaurus, on the other hand, is one of the few dinosaurs be... | [
"In addition to the follow-up questions you mentioned, I'll add my own: ",
"Would that mean such large creatures would be more inclined to spend time in the water where they wouldn't have to worry about that nearly as much, kind of like hippos and elephants can, despite having legs like typical land creatures, or... |
[
"Similar to the Chladni Figures, are there 1-dimentional nodes on the surface of the Earth during the earthquake, i.e. the lines (curves) of points that act like wave's nodes, with locally smallest amplitude?"
] | [
false
] | null | [
"Interesting question. My suspicion is probably not. Chladni patterns are standing waves because they are resonances on a plate, like a 2D analog of a vibrating string. Seismic waves, in contrast, radiate outward from the source and dissipate with distance, more like the ripples on a pond."
] | [
"If you have problem imagining what I mean, try to see these videos:",
"Chladni Sound Figures (U2-05-02)\n",
"https://www.youtube.com/watch?v=nqx_joZFLDI",
"Chladni Figures - random couscous snaps into beautiful patterns\n",
"https://www.youtube.com/watch?v=CR_XL192wXw"
] | [
"I think the intuition here is correct that with earthquakes there can be local differences in wave amplitude due to interference in regions subjected to reflected/refracted energy or from multiple sources. But, the likelihood of source dynamics and governing spatial geometry resulting in stationary nodes seems ver... |
[
"If we were to construct a tube going from the surface of the earth to outer space, would the vaccum of space create a sucking action that could be used as some sort of garbage shoot?"
] | [
false
] | null | [
"Not likely as the vacuum would be immediately replaced by incoming air."
] | [
"No.\nThe vacuum of space is there now, and it isn't sucking much out into it. Believe it or not, gravity is what holds our atmosphere in place, so if you were to build a big tube going into the vacuum of space, gravity would keep the air in the bottom of the tube from escaping; the same way it does now without a ... | [
"The only technological problem to solve is that we would need a very long, very strong rope. There is no solution at the moment, but there are ideas (some of them involving carbon nanotubes)",
"This is not the only problem with a space elevator. The lower part of the cable will be subject to high winds while the... |
[
"Can bubbling result from cooling as opposed to heating of a liquid?"
] | [
false
] | [deleted] | [
"You are talking about a dissolved gas. This is not what happens in an autoclaved liquid; the phase transition is a not dissolved aqueous species to gas but rather liquid water to water vapor."
] | [
"You are talking about a dissolved gas. This is not what happens in an autoclaved liquid; the phase transition is a not dissolved aqueous species to gas but rather liquid water to water vapor."
] | [
"Boiling is actually a cooling process. That is to say, when a liquid boils, energy from the liquid is being removed into the vapor phase.",
"It is possible to achieve \"boiling\" by cooling things rapidly due to phase separation. I learned this first experimentally by putting an opened beer in liquid nitrogen ... |
[
"If you were sitting in an open field when an earthquake happened, how bad would it have to be to be deadly?"
] | [
false
] | null | [
"what would you expect to kill you then? "
] | [
"Just the shaking? I was wondering if it the shaking itself could get bad enough to kill someone"
] | [
"You would have an acceleration equivalent to about 9 ish G's in order to have internal damage, and that's just not going to happen in an earthquake."
] |
[
"Why does air become hot or cold when you blow/suck through material (e.g. your clothes)"
] | [
false
] | [deleted] | [
"Because comparatively, you are blowing out considerably warmer air after it was heated up from your internal body heat. The deal with the cloth, is that it slows down the air a bit after exiting your mouth, and therefore feels even hotter because it sticks around longer, compared to just blowing on your skin norma... | [
"Going off on a bit of a tangent: its important to realize that there is a difference between actual measured (with a thermometer) and perceived (through physical touch and brain signal interpretation) temperature. Take three bowls, one with room temperature water, one with hot water, and one with cold water. Put... | [
"ty all makes sense now :)"
] |
[
"How much does nutrition actually affect a person's height?"
] | [
false
] | null | [
"20% - 40% of human height.",
"20% - 40% of human height variation, not 20-40 percent of human height. These aren't the same. "
] | [
"The question is not being answered. Yes, a significant portion of height is determined by environmental factors, obviously if malnourished, height will be affected.",
"What I think the OP is wondering is, in a 1st world society where calories and a wide variety of foods are abundant, what significance is specifi... | [
"http://www.scientificamerican.com/article.cfm?id=how-much-of-human-height",
"This article claims that nutrition is quite significant. It suggests that nutrition and environmental factors accounts for 20% - 40% of human height.",
"Edit: 20% - 40% of human height variation, not human height."
] |
[
"When a doctor says to a patient that they have 6 months to live, how do they know?"
] | [
false
] | null | [
"Ultimately, what you are inquiring about is the ",
"prognosis.",
" Once you have been diagnosed with a particular disease and it's severity, it is not too difficult to predict the outcome for you based on the statistical experiences of previous patients in your condition. Sure sometimes a patient that should... | [
"A good doctor will also give you some statistical numbers. ",
"I.e. 95% of patients with similar condition do not live past 6 months. "
] | [
"Do they also undershoot the life expectancy so the family won't be mad if the guy dies earlier?"
] |
[
"My grandpa died of Alzheimer's years ago, but exhibited some strange behavior/symptoms. How are these possible?"
] | [
false
] | null | [
"We cannot speculate on individual cases like this. "
] | [
"Why not?"
] | [
"Because we don't offer medical advice and we don't want to comment on individual medical cases. We don't want the personal medical information posted here. We've also found that anecdotal questions lead to anecdotal answers, which are not allowed. We also don't allow speculation, and speculation is almost always n... |
[
"At what point in time do we stop seeing wolf fossils near humans and start seeing \"dog\" fossils associated with humans?"
] | [
false
] | Did dogs also go through intermediaries to transition between wolf and dog? Ie, we have H. erectus before H. sapien. Or are modern dog and modern wolves too similar ro be classified differently? | [
"There's almost no chance wolves weren't a food source, especially from hunting. Realistically speaking they're less dangerous than a lot of large herbivores and if you've hunters capable of safely taking down deer, boar etc, you can handle wolves. And if you're following a herd of deer, you'll find wolves. "
] | [
"It's not clear-cut, but not because wolves and dogs are skeletally identical (they're not). Dog and wolf fossils are found at the same site as late as the ",
"Mesolithic",
", probably because they played different roles: dogs for pets, wolves for butchering."
] | [
"dogs for pets, wolves for butchering.",
"That's interesting. Is there fossil evidence that wolves were hunted for food then?"
] |
[
"What does it mean to be double jointed?"
] | [
false
] | I've heard people being double jointed in wrists, thumbs and shoulders. Some people claim to be double jointed and are extra flexible in said region. I can twist my shoulders all the way around like in this video (that's not me). Is that double jointed-ness or something else? What is a double joint? Is it actually just a misnomer for something else? | [
"'Double jointedness' refers to joint hypermobility. It can affect one, or multiple joints in the body and is characterised by an ability to extend or flex a joint beyond the typical range.",
"Most commonly, hypermobility is caused by misaligned joints, abnormally shaped bones or some sort of connective tissue de... | [
"Double-jointedness is a lay-term for hyper-laxity of constraining elements in the joint. All joints have degrees of freedom for motion but are constrained by bony and soft-tissue anatomy. In a person with hyper-laxity, either the bony constraints are inadequate, or the ligamentous constraints are more elastic than... | [
"It's a misnomer, there's no such thing as being double jointed. Rather, the proper term would be hypermobility. A number of things can contribute to this including weak/loosened ligaments, shape of the bone, and tone of the muscles surrounding/supporting a particular joint. ",
"See: ",
"Hypermobility",
"Edit... |
[
"On average, how far back do we need to trace an individual's family tree in order to find their most recent common ancestor with any other random person from the population?"
] | [
false
] | null | [
"I'm not sure why you think that statistics won't work in this case. Statistics never gives \"the answer.\" It gives ",
" together with a range of confidence or probability. In this case a simple demographic model could be devised that provided an answer quite easily, but with a very broad confidence interval. On... | [
"That would only be true if the distribution of relatedness among humans was flat or normal. In fact the distribution is highly skewed. The vast majority of people around the world are very closely related and only a few isolated populations are more distantly related to the rest. So if you pick two random people f... | [
"That would only be true if the distribution of relatedness among humans was flat or normal. In fact the distribution is highly skewed. The vast majority of people around the world are very closely related and only a few isolated populations are more distantly related to the rest. So if you pick two random people f... |
[
"After a bone marrow transplant do you produce blood with a different set of DNA?"
] | [
false
] | null | [
"Yes definitely - and with this comes cells that may also react to \"self\" antigens in the new host so careful matching is required. Otherwise graft vs host disease may occur. On the other hand, in cases of cancer a tiny bit of this is OK as there may also be a graft vs cancer effect.",
"http://www.ncbi.nlm.ni... | [
"Not only blood - your immune system will be of an entirely different genetic code as well. \nIt depends on exactly how the process is done - in some cases your bone marrow can be entirely depleted, and a transplant will give you an entirely new system. On the other hand, with a partial transplant, you will have bo... | [
"Your body is constantly making both lymphocytes (T cells, B cells and NK cells) and leukocytes (granulocytes) - they aren't produced once and then never again like ovarian follicle cells.\nThese immune cell types come from the stem cells present in the bone marrow - if it weren't for this, adaptive immunity would ... |
[
"Why does air moved through a fan feel cooler?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScience",
"/r/askscience",
"For more information regarding this and similar issues, please see our ",
"guidelines.",
"You can find the answer by searching for something like \"fan cool air... | [
"Did some searching and all and it answers the more basic end of why our bodies feel cooler, but in a closed system (imagining somehow that the fan didn't need electricity from an outside source) ",
"Wouldn't a fan just eventually make things hotter? What I read was it was the particles random movement that deter... | [
"I think all of your questions can be answered by these posts:",
"https://www.reddit.com/r/askscience/comments/1hv26j/why_does_air_seem_to_cool_as_it_moves_like_from_a/",
"https://www.reddit.com/r/askscience/comments/u2qpd/why_does_air_blowing_from_a_fan_feel_cooler_than/",
"https://www.reddit.com/r/askscienc... |
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