title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Physically, what could this black orb near the sun be? (video)"
] | [
false
] | The video depicts a Jupiter-sized black orb siphoning something off the surface of the sun, then zooms away. You can cross-reference images and data from SOHO (solar and heliospheric observatory) with the dates to see that these are in fact authentic images. BLACK ORB: SOHO: From the size of the object, would it be mo... | [
"Here's ",
"a paper",
" authored by NASA researchers (et al) that talks about coronal prominence cavities, and includes some images of some past cavities that are every bit as large as this one."
] | [
"So what? Why not explain why you think it's correct or challenge the guy and win him over to your opinion?",
"The explanation was offered. He dismissed it without any reason. It is not anyone's obligation to win him over. Nobody cares whether he understands or believes the explanation or not - especially when he... | [
"I'm pretty sure NASA explained this in a video on YouTube already. There were posts about this a while ago. Search for it and you'll find it."
] |
[
"How long does it take, on average, for a human to develop scurvy due to a total lack of Vitamin C?"
] | [
false
] | How long does it take, on average, for a human to develop scurvy due to a total lack of Vitamin C? I know Vitamin C is basically everywhere in most diets of the world. However, in a "what-if" scenario, how long would a human have if he or she was devoid of any Vitamin C intake to develop the disease of scurvy. I assume... | [
"Lots of responses with people pontificating about things but no one answering the question.",
"\"Symptoms of scurvy generally develop after at least 3 months of severe or total vitamin C deficiency.\"",
"http://dermnetnz.org/systemic/scurvy.html"
] | [
"Meat also contains some vitamin C.",
"I'm sure some populations don't get the ",
" amount of vitamin C, but there's a difference between getting a sub-optimal amount of something, and having so low an amount that it makes you actively sick."
] | [
"Meat, specifically meat from carnivores, often has enough vitamin C. Many animals can synthesize it on their own.",
"The issue is that Vitamin C breaks down very easily, so you need to eat fresh meat that hasn't been overcooked or processed."
] |
[
"How can a speaker produce more than one sound at a time?"
] | [
false
] | I can visualize how a speaker can make a sound by vibrating at a certain frequency, but how can it create more than one sound at the same time? It can't vibrate at two different frequencies can it? Am I wrong about how speakers work? Edit: Thanks for the answers! | [
"Oh man, what a good looking question.",
"The answer is that sounds are waves, which have the property of ",
"superposition",
". This means that the ",
" wave coming from a multitude of sources is simply the addition of all the sound waves coming from each of those individual sources. ",
"What a speaker d... | [
"Allow me to illustrate this with a ",
" crude ",
" ",
"and now accurate drawing",
". EDIT: The original gives you an idea of multiple waveforms, but as ",
" pointed out, is ultimately incorrect. The new drawing is identical to my followup to this comment.",
"NOTE: While I do not possess any variety... | [
"I Forgot! I ",
" own FT analysis software (Sonar 7, DAW/Sequencer). I did one MUCH better -",
"ACTUAL visualization of the resultant waveform consisting of 4 different frequencies",
".",
"So, OP - combine that with the basic image in my previous post, and the resultant waveform at the bottom is the actua... |
[
"Is eating grains bad for us? Is a \"paleo\" diet better for our health?"
] | [
false
] | I am considering the paleo diet/"lifestyle", eating mostly proteins, vegetables, and cutting out processed and fast foods. I have been doing research on the subject, but I thought I'd come here to see what scientists have to say about it. Thanks. | [
"please no personal anecdote. That is not a scientific answer to the question. Scientific answers only please.",
"Edit: my reply to bib4tuna, since apparently that's already downvoted to oblivion too:",
"attempted to fix the below.",
"Books are notoriously unreliable where the author cherry picks data to supp... | [
"In terms of health, you would be hard-pressed to claim that grain-free diets are the key to healthy lives. When you look at the ",
"zones",
" around the world where people live the longest, they all eat grains (and refined grains in the case of the Okinawans). So, grains are clearly compatible with healthy liv... | [
"your pedantry is spot on. I was being overly general. Thanks for the catch."
] |
[
"Why is earth's orbit elliptical and not round like that of a revolving ball attached to a string?"
] | [
false
] | I know the Kepler's law of planetary motion but still whats the reason its not perfectly circular orbit? | [
"No real-life orbit is ",
" circular. Circular orbits are a special case of elliptical orbits where the two foci of the orbit coincide. ",
"There are many ways to make an unstable orbit, and there are many ways to make a stable but elliptical orbit. There's only one way to make a perfectly circular orbit, and t... | [
"A better question is, why would it be circular? There are infinite ways to make an elliptical orbit but just one very specific way to have a circular one."
] | [
"You're correct, I meant to signify that it was speculation about qualifying an absolute statement (\"No real-life orbit\"), since it's not proven that there are no perfectly circular orbits. I attempted to identify one condition that could enable an achievable circular orbit (planck length), but agree that it was ... |
[
"How is it that we can figure out properties of planets and stars that are so far away?"
] | [
false
] | For example, apparently there is a planet made of diamonds extremely far away. How did someone figure that out when all they really had was a high powered telescope and no way to confirm its properties? | [
"There's a variety of techniques that are used to gather various properties. Some of the key ones:",
"1) Doppler Radial Velocity Measurements. The planet and star orbit around a common center of mass, so as the planet goes around the sun, the sun moves a little bit too. Just like how the frequency of sound from a... | [
"This does not really answer the question. What he wants to know is how they for example know there is liquid water on a certain planet, or what kind of other elements are present and in which quantities. "
] | [
"astronomers use ",
"spectrometers",
" to determine things like these"
] |
[
"Why does your voice get deeper as you go without sleep"
] | [
false
] | I was watching a show about sleep deprivation, and noticed as the participants went without sleep, their voices substantially deepened. They even mentioned it a few time's but gave no indication as to why. Is there science here? | [
"The vocal chords need rest as does the rest of the body. When fatigued, they dont respond as well and vibrate at a lower rate, resulting in a lower pitch. Mucus health can affect this as well. Unhealthy thick mucus can have a similiar affect. Drink a glass of water first thing in the morning to rehydrate and see ... | [
"I'm not going to speculate, but if I may also add to this, why do our voices sound deeper when we first wake up?"
] | [
"I'll try that! Thanks For the knowledge! :-)"
] |
[
"What are the logistical problems with installing a waterwheel connected to a turbine and generator half way down a big waterfall to create a never ending source of electricity?"
] | [
false
] | null | [
"Isn't this just ",
"hydroelectric power",
"?"
] | [
"Yeah basically. But hydroelectric requires a massive undertaking of landscaping the environment, and it is usually not a massive amount of water falling at a time (could be wrong about that)"
] | [
"Hydroelectric plants are built where there is a very large volume of water flowing, otherwise they wouldn't generate much energy. Some of them do in fact take advantage of natural falls."
] |
[
"Does the age of the universe really influence the gravitational constant?"
] | [
false
] | [deleted] | [
"He's probably referring to Dirac's ",
"large numbers hypothesis",
", which posits that various constants, including the gravitational constant, change over cosmological times.",
"It wasn't based on any physical arguments but rather on numerological ones: various physical \"constants\" could be arranged into ... | [
"Thank you. I think that was what he was referring to."
] | [
"It wasn't based on any physical arguments but rather on numerological ones: various physical \"constants\" could be arranged into ratios that were all huge, but all looked related ",
"Is this similar to \"the Earth is almost exactly 500 light-seconds from the Sun; for it to be such a round number can't be a coin... |
[
"How does light get 'sucked into' a black hole if it has no mass?"
] | [
false
] | [deleted] | [
"It doesnt get \"sucked in\", it continues in a straight line through space - the difference is that space curves ",
" a blackhole....this space curvature is what we call ",
"."
] | [
"In Newtonian gravity, mass acts on mass to produce gravity, so in that context, it is indeed puzzling. In general relativity (our current best theory of gravity), the presence of matter curves spacetime (this is the black hole in this case), and particles (massless or massive) follow straight lines on this curved ... | [
"First, gravity isn't a change in curvature, it is the curvature.",
"Anyway, it's because it's curvature of space",
". In ordinary flat, gravity-less spacetime, an object at spatial-rest relative to some inertial frame at an initial time will not move in space in that frame. It will, however, continue to move i... |
[
"Why is it easy to become addicted to things, but hard to quit?"
] | [
false
] | I ask this because it seems that if you do something once sometiimes, you'll want more. For example if you look at porn a few times you may become addicted, or if you try a cigarette a couple of times your body may crave more. But if you want to quit it's really challenging, why is that? | [
"The basic explanation is that addiction taps into a natural part of the brain's reinforcement processes. For example, you are thirsty. You want water. You drink. then you are not thirsty anymore. ",
"The addiction creates a new need. You take nicotine. The ventral tegmental neurons fire action potentials at high... | [
"Extinction Burst is a good term for further reading on this, basically that's the phrase for when you're trying to break an addictive habit (or any conditioned response), where your brain goes full force into forcing you to reinforce that habit."
] | [
"Habits die hard. You get into an addiction, then your mind and body gets in synch with the addiction. you're entrenched in it; your subconscious gets used to the rhythm. When you want to quit there is a backlash; an inertia which prevents instant withdrawal. Hence many addicts experience difficulty in suddenly sto... |
[
"Why do people smile or laugh when in bad/sad situations that one shouldn't laugh in?"
] | [
false
] | Such as telling someone a loved one died. | [
"Most of the time, normative individuals (that is, people that are not diagnosed with some mental disorder or do not exhibit some outlying trait) exhibit predictable emotional reactions to stimuli. For example, when someone's loved one dies, we ",
" them to exhibit sadness, grief, loneliness, vulnerability, etc. ... | [
"Thanks a bunch for the answer!"
] | [
"I guess the part about anxiety is the most familiar one. If people are experiencing anxiety in a social situation, or about their own feelings, they might laugh to diffuse tension or divert attention. Like people who are afraid of being angry might laugh when they feel anger (functioning like a secondary emotion).... |
[
"Why does copper darken ? I'm guessing oxidation, but seeking further explanation."
] | [
false
] | I just moved to a new house about 2 months ago. My mother has some gold plated jewellery made of brass or bronze(not sure which, but it contains copper). She's been complaining that the jewellery has darkened because of some bad omens. I would like to explain to her that it is because of the natural process of oxidatio... | [
"The coating is protecting her items. Nothing \"bad\" about that. You can also electrolytically reverse the process and give her some good omens(?) instead. "
] | [
"Copper will oxidize to form a reddish copper(I) oxide layer, and in moist conditions will form various copper hydroxide and carbonate compounds (these are the blue-green patina you see on old copper roofs). If the copper turned black/gray, a more likely cause is formation of copper sulfide after exposure to hydro... | [
"So you're suggesting that there are some sulphur compounds in air in the house. Any ideas on possible sources ? "
] |
[
"I've heard of genetically engineering bio-luminescence into non-bio-luminescent animals. Is this a simply done task now? What tools would I need to make a species, say... ants, bio-luminescent?"
] | [
false
] | null | [
"Not even close. ",
"Ants are VERY complex, in that you would first have to study their rearing behaviour, you'd have to get hold of some ant enbryos, figure out just how in the hell the particualr ants you are working with behave, then isolate some eggs and sperm, THEN breed yourself a queen, then figure out how... | [
"Not even close. ",
"Ants are VERY complex, in that you would first have to study their rearing behaviour, you'd have to get hold of some ant enbryos, figure out just how in the hell the particualr ants you are working with behave, then isolate some eggs and sperm, THEN breed yourself a queen, then figure out how... | [
"I had a guy like you in my old lab. ",
"I miss him."
] |
[
"Are STIs/STDs transmitted immediately?"
] | [
false
] | If someone is infected with an STI/STD and has unprotected sex with someone who doesn't have it, is it transmitted immediately, the second of penetration? Or is it like the longer intercourse lasts, the more likely the chances of transmission? | [
"Also, if you stab someone in the hand with an HIV infected needle, how long do you have before cutting off their hand/arm wouldn't stop the infection from spreading to the body?"
] | [
"Most STDs are transmitted through contact between mucosal surfaces. The infectious particles obviously can't move instantaneously, as they have to move across several barriers. Longer periods of contact and, more importantly, contact between areas with any defects in the mucosal surfaces, will increase the chanc... | [
"Well, the infection rate for a hollowpoint needle stick is only about 0.3% for HIV. You would probably be better off just starting prophylaxis with antiretrovirals."
] |
[
"Besides explosive size, what exactly is the difference between novas, supernovas, and hypernovas?"
] | [
false
] | null | [
"A nova requires a white dwarf (the core of a dead star) and a nearby normal star. If the nearby star gets too close, it will start ",
"transferring its own mass onto the white dwarf",
", and that mass will swirl around the white dwarf in an \"accretion disk\". The mass will also fall onto the surface of the ... | [
"Small correction, a nova does not happen in the accretion disk, but in the boundary layer on the surface of the white dwarf. ",
"The progenitor of Type Ia supernovae is still debatable, though recent research suggests that the double degenerate channel, in which 2 white dwarves merge, is what happens instead of ... | [
"We know iron to be the heaviest element that stars can make (stably) because it is the ",
"nucleus with the highest binding energy",
". Above iron, fusion requires energy; below it, fusion releases energy. By fusing iron, therefore, the star will ",
" energy, not create it, which will cause it to contract, i... |
[
"Skin fusing to surfaces: how the fuck?"
] | [
false
] | [deleted] | [
"Just to clarify, \"lack of airflow\" should be \"lack of blood flow.\" For those curious about this problem, read up on ",
"bedsores",
", a major problem with patients staying long-term in hospitals. "
] | [
"It wouldn't even require abrasion. The combination of constant pressure, lack of airflow and constant moistness is enough to compromise the skin's integrity. Then there's the additional moisture, ammonia and bacterial growth aided and abetted by the urine and feces that are present and being squished into the same... | [
"when your skin is healing, it can form a layer over whatever is covering it, similar to what your skin does if you get a splinter. i don't know if you have ever had an injury that needed medical gauze, but when you put that stuff on, if you leave it on too long (like a day or two), your skin starts to heal over it... |
[
"Can you put a deciduous tree in a greenhouse (or similar climate control) and it never hibernate?"
] | [
false
] | ...or do deciduous trees to hibernate and lose their leaves? | [
"You could have a deciduous tree with a \"chilling requirement\" in a greenhouse without hibernation for a few years, but it would be a sickly tree that would essentially die of exhaustion. Also it is almost impossible to force these trees to reproduce without a chilling period, as shown in this paper by the hortic... | [
"There are several species of tropical deciduous trees. These do not hibernate, although they may (depending on the tree) require a dry season.",
"here is a discussion of tropical deciduous trees: ",
"http://ntsavanna.com/deciduous-trees-in-the-tropics/"
] | [
"You could have a deciduous tree with a \"chilling requirement\" ",
"What does this mean? "
] |
[
"Why are carnivores generally more intelligent than herbivores?"
] | [
false
] | Dolphins and primates have the highest brain-to-body ratio and are usually called one of the smartest mammals. Octopi and squid are the smartest invertebrates. A large part of these animals diet, with the exception of primates being omnivores, is from other animals. Is this because they eat other animals, or is there s... | [
"There are some nutrients not found in abundance, or at all, in plants that herbivores need to synthesize themselves, for example, cholesterol, vitamin d, vitamin b12, car nosing, creatinine, etc. There are also nutrients that are in greater abundance in a herbivorous diet. I suppose it could be argued that things ... | [
"In general, it requires more cognitive power to hunt something than it does to avoid being hunted. Predators need to be able to plan routes of attack, select which animal would be easiest to catch, adjust their course of attack on the fly, possibly communicate with other pack members to have a coordinated effort. ... | [
"Both? There are animals there, they are a source of nutrition, things evolve to take advantage of that. Carnivores get a lot more energy from a smaller volume of food, and they expend large amounts of energy in a short time instead of small amounts all day to obtain that nutrition. It IS a biological advantage to ... |
[
"What’s the deal with this new “signal we’ve never seen before” from space?"
] | [
false
] | I don’t have the article handy but I’m sure many of you have seen it floating around. Obviously the need in me would love for this to be different (you know what I mean) but I’m sure it’s some natural phenomenon we just haven’t seen yet. What is our current best guess? | [
"Mostly because we keep finding new stuff and it keeps having a non-alien explanation. ",
"Pulsars are a great example-- they are basically lighthouses in space, incredibly regular repeating signals. The first pulsar discovered was somewhat jokingly named LGM-1 (for Little Green Men)... ",
"The other problem ... | [
"Completely with you on that, I just find the psychology around our beliefs of what's out in the wider universe quite interesting. There's a strange blend of exceptionalism, hope, irrationality, fear and all sorts of other things.",
"Personally I'm sure life of some description has, does or will exist somewhere o... | [
"Because aliens don't exist or because its unlikely to be complex life capable of creating anything that would send a signal of any description that would reach us?"
] |
[
"Is reading a book, and listening to an audio book similar enough to say you \"read\" an audio book?"
] | [
false
] | null | [
"This is something I would also like to know as I listen to a lot of trade books in the car while travelling and have wondered if its ",
" actually planting the information into my head or I'm a just listening like a song. "
] | [
"What exactly do you mean by \"doing anything\"?"
] | [
"Fixed, on my phone."
] |
[
"Change of buoyancy when changing from solid to liqiud?"
] | [
false
] | Hello everyone A few days ago i saw an interesting video: a guy put some liquid spermaceti (whale fat) into a tube, closed it and put it into cold water. At first it was floating, but with time it turned liquid because of the cold water and, much to my astonishment, started to sink!. After that, he poured hot water int... | [
"This is demonstrating one-half of a classic lesson on thermal expansion.",
"The Oceanography Society produced this excellent lesson book ",
"Teaching Physical Concepts in Oceanography, an Inquiry-Based Approach",
". It contains several demonstration, all of which are valuable for understanding how the ocean... | [
"Well we have 2 things going on here. First most substances are denser (shrink) as a solid compared to a liquid (ice outstanding). So as it freezes it would become more dense and sink. ",
"However if the tube is truly a constant volume this can work another way. Water changes density as it changes in temp (war... | [
"the density of the water changes, not the tube or its content"
] |
[
"Where Do I Get Science Posters?"
] | [
false
] | null | [
"Hi physicsking 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 fol... | [
"This isn't the right sub for this question. Try ",
"/r/asksciencediscussion",
" maybe"
] | [
"thank you. I will submit it there"
] |
[
"Why can't a mountain be higher than 49,213 feet? What happens at that height?"
] | [
true
] | [deleted] | [
"I don't know the source of that calculation, but it was almost certainly merely an estimate based on someone's quick calculation. I can't find a single mention of that number through Google Scholar, or any other place on the web, which makes me even more dubious of that claim (and there is simply no way it could b... | [
"This is an excellent and comprehensive answer. I would only supplement it with the fact that 49,213 feet is 15,000.1 meters. So someone has calculated it as roughly 15km, it's then been converted into feet, and someone made the error of assuming the number was real.",
"It's really important to note that if the ... | [
"My favorite illustration for explaining this to laypeople is the story of a museum employee telling visitors that a ",
" skeleton is 65,000,012 years old. When asked how such an exact figure could be arrived at, he explains that the skeleton was 65 million years old when he started working there 12 years earlier... |
[
"What is the environmental and long term climate impact of the recent Chile volcano eruption?"
] | [
false
] | I'm curious as to the temperature variations and long term effect the Calbuco volcano eruption will have on the local environment as well as further away. | [
"Locally a big impact mostly from falling ash an air pollution. However globally, I doubt we'll see much impact unless this continues for several months. It is located around 41 S, so not near the tropical regions. For volcanoes to have a global cooling effect, they usually need to be erupting in the tropical re... | [
"Chile is the country. Chili is the food. A chili eruption hopefully does not even leave the house."
] | [
"The large volcanic effects that we have seen in the past are due to particulate matter being thrown up far enough to leave the troposphere and get into the stratosphere (some 20km to 40 km in altitude), where the SO2 can form sulfate aerosols, and this can spread globally. These enhanced aerosol layers can have... |
[
"Is there a reason for the majority of the world's land mass to be above the equator?"
] | [
false
] | null | [
"No. There's no distinction between North and South. It's just happenstance. Mars, for instance, would be basically all ocean in the North, and basically all land in the South, if you poured a bunch of water onto it."
] | [
"I'm guessing what he wants to ask is if there is a known reason why there is much more land on one side of the equator than there is on the other.",
"Perhaps Pangaea was in the northern hemisphere or more in the northern hemisphere? (I have no idea at all...)"
] | [
"No. It's just a result of continental drift. In fact, during the Devonian Period, ",
"Earth's landmass was mostly in the southern hemisphere",
"."
] |
[
"Why does the sound of a spoon hitting the side of a glass cup lower in pitch as I mix instant coffee grains into water?"
] | [
false
] | Basically, I drink coffee most morning and I've noticed that the sound that a spoon makes as it hits the side of a glass full of water when I swirl it around has a certain relatively higher pitch to it. When I add instant coffee grains, the pitch gradually lowers until settling on a certain noticeably lower pitch when ... | [
"The water now has a different density. Sound travels at a different speeds depending on the medium( ie, stuff it's in, in this case, your coffee). That is why you can here digital watches underwater while swimming in a pool. Knowledge is power!"
] | [
"I've experienced similar results when stirring cream/sugar into reheated/microwaved, 8 hour old coffee, but not while the coffee is fresh -- that is to say, tapping a spoon on a glass of fresh coffee after adding cream/sugar results in a higher pitch than stirring cream/sugar into reheated coffee. While I agree th... | [
"Fantastic, thank you so much."
] |
[
"Sleeping is such a waste of time. Science : are there any researches/studies going on that will allow us to stay awake at all times and not crash?"
] | [
false
] | We sleep for a third of our lives. So for 90 years that you will live, you will waste 30 years of it asleep... What a waste. | [
"It may be a waste in terms of productivity, that you're not physically doing anything, but I don't think it's a waste in the sense that your body does a lot of housekeeping style stuff during sleep, and completely avoiding it is probably not a great idea. You can adjust your sleep cycles like some people and make ... | [
"I'm doubtful that a simple chemical solution to sleep is possible for one reason - almost all complex animals do it. Being unconscious for a third of each day is such an evolutionary disadvantage that anything that reduced or removed this need would almost certainly be selected for."
] | [
"I'm sorry, but if I interpreted the question correctly then I don't think you quite answered it entirely. I'm sure the OP (and everyone, for that matter) realizes that sleep is necessary to our body what with all the restorative functions that it provides.",
"However what I think he's asking is if there is any w... |
[
"How do 2 particles get entangled?"
] | [
false
] | i've been watching videos and reading up about a bunch of cosmology and quantum physics stuff and am trying to wrap my head around entanglement. i understand for 2 particles that are entangled, when you measure the spin (or other quantum characteristic) on one you instantaneously know what the spin on the other is, reg... | [
"The specific answer will quite strongly depend on the details of the system which you consider. However, I will try to give you widely applicable explanation.",
"Let us start with what entanglement actually is. To talk about entanglement, we always have to consider systems which can be divided in parts (In this ... | [
"Do I understand it correctly that the entanglement between two particles actually happens naturally all the time, and the real problem is to prevent the two particles from also getting entangled with the environment?",
"In other words, the tricky part is to get \"two, ",
"\" particles entangled?"
] | [
"so my understanding of what you described is that entanglement is a quantum property of a system in which the system parts interact with each other. in your example, the two parts of the system have a wave function (F=f1+f2) and (G=g1+g2) and once they interact, you are then able to describe the system as =(f1+f2)... |
[
"What evidence is there for WIMPs?"
] | [
false
] | Weakly Interacting Massive Particles are the currently favored theory for dark matter but they feel very similar to neutrinos. What evidence is there to convince scientists that dark matter is simply more neutrinos than expected, but another more massive particle (or particles) that has yet to be discovered? | [
"There are particle detectors at the DAMA/LIBRA, CoGeNT, and CRESST experiments that all register small dark matter signals. They have evidence but not conclusive evidence."
] | [
"The difference between neutrinos the sort of WIMPs that are hypothesized to constitute dark matter is that dark matter WIMPs would not be traveling at relativistic speeds (which is why they can form gravitationally bound mass halos), whereas to the best of our our knowledge, essentially all neutrinos travel at rel... | [
"None yet. It's all theoretical math that seems to support the observed data. We're hoping to find evidence from the LHC when it gets to higher energies (and a few other facilities). But we might not find any evidence, in which case it could be back to the drawing board for a whole new idea.",
"Here's a really cu... |
[
"Dr. John Hagelin on the science of consciousness and the unified theory. Pseudoscience?"
] | [
false
] | null | [
"I have a B.S. in biophysics and spent ~ 1 year learning a cursory level of research neuroscience during lab rotations so I'll give you my opinion of this until someone more qualified responds.",
"He is using quantum theory (which is abstract in the first place) to make his philosophy scientific. The glaring fla... | [
"Consciousness has no current operational definition and all theories are probably as valid as each other, yet equally bogus. I have removed this question because the aspect of consciousness cannot really be answered scientifically, though, the aspects of cognition that are said to contribute to consciousness can. ... | [
"Yeh I thought the response to this would be as such. I was just interested if there was any more info people had on this. I see this can't really be answered scientifically so I'm not sure how I could rephrase it..."
] |
[
"\"Two-thirds of the people who have ever reached 65 are alive today.\" Can this really be true?"
] | [
false
] | I saw this at the airport on an HSBC ad. I have trouble believing that, out of the dozens of billions (more?) of humans who have ever lived, two-thirds of those who made it to 65 and lived to tell the tale are alive now. Especially considering that "average" life expectancy was artificially shortened in prior centuries... | [
"First, an answer to your partial question",
"The common statement: \"more people alive today than have ever lived\" is false as far as I am aware. (And as far as ",
"wolfram alpha is aware",
", stating that there have been about 100 billion people ever) ",
"I can imagine though, however, the possibility th... | [
"Don't forget that huge infant mortality rates were a large part of low life expectancy in the past. I'll try to find the interactive graph that showed age breakdown for each year.",
"edit: ",
"here",
", I really love this graph"
] | [
"I've been spending the last three weeks going over survival analysis, and I think seeing such an expertly presented hazard curve and survival curve just made me spooge myself. (Why can't they always come out this nice in the literature?)",
"As an aside, funny how on some years the hazard at t=98 is greater than ... |
[
"Has Rosetta significantly changed our understanding of what comets are?"
] | [
false
] | What I'm curious about is: is the old description of comets as "dirty snowballs" still accurate? Is that craggy surface made of stuff that the solar wind will blow out into a tail? Are things pretty much as we've always been told, but we've got way better images and are learning way more detail, or is there some comp... | [
"Doesn't look like anyone has chimed in yet, and this is getting a lot of votes. So let me just say this for now:",
"Rosetta got there 3 months ago and Philae landed ",
".",
"Scientists have had the data from the lander in their hands for less than a week, and whatever science Rosetta is doing from orbit is j... | [
"I'd like to know what exactly the data is. Temperature readings? Are ground samples being taken and analysed? I mean, I don't even know what else to ask. Why is the probe their in the first place? What do they plan to learn? ",
"Sorry for the ramble of questions. I just realize how little i know about what's ha... | [
"If you want detailed information, the ",
"ESA FAQ page",
" is probably your best bet to get up to speed.",
"I think the basic answer is that it's there to try to get as detailed information about what comets are made of and how they're structured. A lot of the data is going to be spectroscopic which can tell... |
[
"How does a superfluid have a viscosity of 0? If you held some in your palm would it flow through you (temperature notwithstanding)?"
] | [
false
] | null | [
"Contrary to the conventional notions on what constitutes a superfluid, 'zero viscosity' is not achievable in the so-called 'superfluid' state of helium 4, or 'He-II'. In practice, there is always a very low but finite value in the bulk shear viscosity, about 13 microPoise, which occurs somewhere between 1 to 1.5 K... | [
"Picture little fluid bodies as pushing and pulling one another. When they push or pull front to front- in the direction of motion- it's an inertial effect. When one moves and the other is carried as if they were \"holding hands\" it's a viscous effect."
] | [
"Picture little fluid bodies as pushing and pulling one another. When they push or pull front to front- in the direction of motion- it's an inertial effect. When one moves and the other is carried as if they were \"holding hands\" it's a viscous effect."
] |
[
"What color is the dress? Why do some people see blue and black and some people see gold and white when looking at a single image of a dress?"
] | [
false
] | We've heard the clamoring for explanations as to why people perceive so very differently. Sometimes it's blue and black, sometimes it's gold and white. We've heard that it's even "switched" for some people. We've had our experts working on this, and it's surprisingly difficult to come up with a definitive answer! Our p... | [
"(Reposting from the other thread)",
"Hi! me and some other grad students have been discussing this for the last half hour. It's likely due to some kind of colour constancy illusion, where some people are perceiving the context to be something like \"lit by blueish daylight\" and others are perceiving it to be so... | [
"Do you have a reverse of this. I only see blue black and want to try to get it to flip."
] | [
"For the people that only see a white dress. ",
"This is close to what other people are seeing as a blue/black dress.",
" I got this image by just editing the brightness and contrast of the image. Maybe getting this view of the image will help you flip the colors. I see a white dress most of the time. Afte... |
[
"How much tuna is OK per week/month?"
] | [
false
] | With so little fat and so much protein I could go on a tuna-only binge for a few weeks to get extra lean. My question is can this be done without risking harmful effects like mercury buildup? Or can I eat tuna from the can for the next two months? | [
"Here are the ",
"EPA/FDA recommendations",
" for women who are pregnant, may become pregnant, or are nursing, as well as children:",
"Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury.",
"Five of the most commonly eaten fish that are low in mercury ar... | [
"And I see that you're letting a popular diet run away with you just because someone with the title of doctor endorses it, whereas my recommendation is the current consensus of my field as a whole. And I'd bet I can find someone with the title of Doctor who supports pretty much any crackpot theory you can think of... | [
"Don't worry, I know there is evidence that keto works great for weight loss and insulin resistance. If, in the future, I have a patient who had consistently failed to be able to restrict calories/exercise and wanted to try ketogenesis for weight loss, I would provide him/her with the good and bad evidence on both ... |
[
"Are the charges of the proton and electron exactly opposite? If so, why?"
] | [
false
] | Do the two particles have charge of exactly equal magnitude (just opposite sign)? | [
"Yes, they are of exactly equal magnitude. Why this should be the case is an interesting question, to which we do not have a full answer. There are three approaches to this question that I can outline.",
"Before doing so, let me note that electric charge tells you how strongly a particle feels the electromagnet... | [
"\"Grand unification\" is the term we use to describe the unification of the non-gravitational forces. Gravity certainly is fundamental, but gravity has a mathematical structure that appears to be rather different from that of the other forces. On the other hand, the strong, weak, and electromagnetic forces all h... | [
"Quarks in hadrons are not bound together by the electromagnetic force, they are bound by the strong interaction. I like your last sentence. We actually have no idea why a proton should have the exact same charge magnitude as an electron, one hypothesis is that if there are many universes with varying laws of phy... |
[
"Are LEO satellites visible with the naked eye?"
] | [
false
] | null | [
"Oh yes! The most famous satellite visible to the naked eye is the ISS. Depending on how the sunlight is getting reflected by it or its solar panels, it can even appear brighter than Venus with an apparent magnitude of roughly ",
"-5.9",
". Other LEO objects can reach similar magnitudes, depending on how much l... | [
"I was actually out waiting for the ISS to fly over and I saw the satellites. At first I thought it was space junk. Hey, it was 5:50am lol. "
] | [
"I was actually out waiting for the ISS to fly over and I saw the satellites. At first I thought it was space junk. Hey, it was 5:50am lol. "
] |
[
"Why can't we use integration in carbon-13 NMR?"
] | [
false
] | The normal answer is because only around 1% of naturally occuring carbon is carbon-13, so there is normally only one C-13 atom per molecule. But this doesn't seem satifactory because surely for a large enough sample the ratio of C-13 atoms in the different environments in all molecules would match the ratios of the car... | [
"I think relaxation time plays also a role.\nDifferent carbon types (sp3, sp2,...; carbonyl vs alkene,...) won't have the same relaxation time and if in your pulse sequence you don't wait for full relaxation then integration may not be reliable.\nN.B. That is also true for proton (and certainly most of other nuclei... | [
"Well that actually is part of the answer. The reason a 1% abundance ruins our ability to perform integration is that when we actually go to collect a C-13 spectra we have a very high signal to noise ratio compared to H-1 or other NMR spectra of abundant isotopes. ",
"If you have ever seen a C-13 spectra that ha... | [
"A few reasons, but probably the biggest is because we usually decouple C",
" spectra, which distorts the peak heights and removes the proportionality between peak area and number of atoms.",
"More here:",
"http://www.chem.wisc.edu/areas/reich/nmr/05-hmr-01-integration.htm"
] |
[
"melting point depression: how does it work?"
] | [
false
] | the first lab I did in organic chem was a melting point lab. In it we combined solid cinnamic acid and solid uric acid, both crushed, and the melting point of the mix was less than either of the two compounds while they were pure. I can understand if the two were in liquid form, and how the intermolecular forces would ... | [
"The mixture of solids can actually be described thermodynamically in the same way as an aqueous solution mixture. The regular solution model of thermodynamics treats chemical interactions on a global average scale, without specifically describing the atomic interactions. Two contributions, from the increased ent... | [
"I didn't know that regular solution theory described phase transitions! That is interesting!"
] | [
"Phase transformations are described by a (energy) difference between states. The regular solutions model is capable of decribing a \"solid solution\" state which covers most simple liquids and metals. ",
"The same concept can be extended to describe oxides and semiconductors using lattice theory. (each lattice... |
[
"If dry ice is made of CO2, and CO2 is transparent, why does it produce a white fog?"
] | [
false
] | null | [
"It's tiny droplets of liquid water condensed by the extreme cold of the dry ice - just like you can see your breath when you're outside on a cold day. "
] | [
"Ah, so the fog is made of the water, not the co2. In that case, I thought water had to heat up to make vapor, not cool down. What gives?"
] | [
"Ah, so the fog is made of the water, not the co2. In that case, I thought water had to heat up to make vapor, not cool down. What gives?"
] |
[
"Positive and negative ends of battery same as positive and negative charge?"
] | [
false
] | My understanding that in electricity, one end provides electrons and the other end doesn't. Not sure which is positive and which is negative in this case. Is this the same thing as the positive charge that a proton possesses and the negative charge an electron has? | [
"In conventional battery labeling, the positive terminal is the source of high-energy electrons (electron donor) and the negative terminal is where low-energy electrons go (electron acceptor). ",
"In today's circuits, charge carriers (that is, particles that are responsible for moving charge around and doing the ... | [
"I don't think that's quite right. The convention for electrical current is that it flows from the positive to the negative terminal. This was determined before we discovered electrons are the carrier of electric charge, so while we often describe current as traveling from the positive to the negative terminal, t... | [
"When a battery is not connected to a circuit there are a surplus of electrons located at the negative terminal and a shortage of electrons located at the positive terminal. While the battery is performing work in a circuit, electrons move out of the battery at the negative terminal, then move through the circuit,... |
[
"How did the \"Mother Lode\" vein of California gold develop?"
] | [
false
] | And why did it end up concentrating where it did? I have a very basic understanding that it was deposited there as tectonic plates collided and formed the Sierra Nevada mountain range, but where was the gold and in what way was it distributed before the plates collided? (I'd love to learn as much as you can tell me abo... | [
"160-165 million years ago, as North America trudged slowly west, there was ",
" in its way. This was probably (but not ",
") an island arc, chilling out minding its own business as an entire continent rolled towards it. And eventually, in painfully slow-motion, the North American plate collided with the island... | [
"That's a fantastic answer, and very interesting, thank you!",
"Can I ask a couple follow-up questions to understand a few things better?",
"So the hot, pressurized water carrying the dissolved gold up toward the surface was also carrying other minerals with it that were also dissolved out of the rock? And when... | [
"You're welcome!",
"this process can happen pretty much instantaneously"
] |
[
"Is brilliant green (zelyonka) actually an antiseptic?"
] | [
false
] | I don't think this is used in Western countries, but nations that were part of the former USSR seem to still use a as a wound treatment (similar to/as well as iodine). It's something I grew up with and never really thought about, but when I looked it up today, I'm not really understanding if the dye itself has any acti... | [
"It’s been used as an antiseptic since WW1. It’s not been widely used or studied in the west. I could find one ",
"note",
" published to the British Medical Journal in 1916 about its use in the WW1 theater.",
"I see some references to it being effective against gram positive bacteria and seems to be a compone... | [
"Not directly related but maybe lending credence to the potential benefits of dyes in medical usage, there is another dye (phenazopyridine) that is used as a medication to provide pain relief during urinary tract infections. It ends up coloring your urine a very bright orange."
] | [
"Interesting! Thanks for the info, I'll look up those to learn more 😁"
] |
[
"How do bats avoid confusion on the frequencies they make?"
] | [
false
] | null | [
"Bats will actually alter their frequency based on surrounding bats so that each of them will have a unique frequency. Typically one will shift upward and the other downward but how exactly it plays it isn't understood entirely. The technical term for this type of behavior is Jamming Avoidance Response. This may no... | [
"this is copy pasted from an answer i gave a couple months ago:",
"Yovel et al (2009) found that bats can identify individuals by their voice - very similar to the way you can tell your friends voices apart!",
"Some of it also has to do with the timing of the signal - bats have muscles around their ear bones th... | [
"Though it's not a direct answer, I hope it may be considered relevant. I don't have credentials personally, but Richard Feynman does.",
"Richard P. Feynman Talks About Waves",
" ",
"Give him a minute to get going. Note, he's talking about light waves, not sound waves. But if you're thinking about this kind ... |
[
"Was the Chernobyl graphite radioactive due to induced radioactivity?"
] | [
false
] | Hi Just watched HBO's Chernobyl series for the 2nd time (wow that is some good TV) and I was a bit puzzled about why the graphite blocks were so radioactive. Is it simply because they were coated in fission products, or were did they become radioactive themselves as a result from induced radiation from being present in... | [
"During normal operation, the fission products should remain contained within the fuel and not really mix with the moderator material, but the moderator itself will be activated due to all the neutrons around in the core. So the fission products make up the bulk of the radioactivity in the core, but activation of t... | [
"Beside the damaged fuel contaminating the graphite, even in normal operation graphite reactors (RBMK for Cherobyl, but also Magnox/AGR, or UNGG), the graphite is naturally activated by the neutron flux. Even without an accident, handling gaphite fresh from the core by hand would be \"detrimental to your health\". ... | [
"The main objective of a nuke remains the blast. Make a big boom that destroys stuff.",
"\nAll the material of the bomb (the fuel but also the casing itself) is activated (to various levels) by the intense neutron flux and fall down as fallouts, aka radioactive contamination adding the \"bonus\" of area denial fo... |
[
"How is the power of nuclear weapons increased?"
] | [
false
] | null | [
"So most nuclear warheads in the current stockpile are of the Teller-Ulam design. You have a small(ish) fission primary, which initiates the whole thing. This creates the conditions necessary for fusion in the secondary. The neutrons produced in the secondary, in turn, cause fission in the natural uranium casing th... | [
"It's bad enough that to get a 10 fold increase in blast radius, you need a 1000fold increase in warhead power.",
"The rule of thumb for blast scaling, as an aside, is that to increase the blast radius by a factor of two, you need to increase the yield by a factor of eight. Thermal effects work a bit more efficie... | [
"Nuclear weapons work by releasing energy from nuclear fission reactions, and often nuclear fusion reactions.",
"Increasing nuclear fission bombs is a matter of making sure more material undergoes fissioning before the explosion of the bomb decomposes itself. This can range from increasing the efficiency of the r... |
[
"Is it possible for there to be some sort of extra-terrestrial species who's time moves at a different \"speed\" than ours? (I'll try to explain in text)"
] | [
false
] | null | [
"Time is just a measurement tool, like distance. You can call a meter anything you like, but it's still the same distance in the same frame of reference. Same with time. How we comprehend it is another thing I suppose."
] | [
"Right, time is a measuring tool. I'm curious about comprehension though. Is something like mentioned above beyond current human understanding?"
] | [
"I guess it's possible for something to not notice the speed of time like something else. "
] |
[
"Computer Radiators: Actually a sensible idea, or pie in the sky that's inefficient?"
] | [
false
] | Been reading this article, and the idea seems sound: instead of radiators, have a computer system designed like a radiator that is a part of a network to crunch stuff, and as a side-product you get heat. As a layman with no idea, this sounds sensible as ideas go, but what do our Engineering and Computing sciencers thin... | [
" It works, but is probably not very practical.",
" Computers generate heat and do so very efficiently. Practically every joule of energy you put into a computer ends up as heat coming out of one of its components. So the idea to use a computer instead of a regular electric radiator is quite natural.",
"The dev... | [
"Computers generate heat and do so very efficiently.",
"If your primary goal is to heat your house, then that's not quite true. Computers can give you at most one joule of heat for every joule of electricity. That's ",
". A heat pump can get you 2-3. ",
"In some places (Norway) resistive heating is illegal be... | [
"In some places (Norway) resistive heating is illegal because its 100% efficiency is deemed too bad.",
"Not true, you can buy all kinds of resistive heaters in Norway, and using them is not illegal. There might be some kind of regulation regarding office complexes or something that I'm not aware of, though.",
"... |
[
"Does stomach size have an effect on gaining weight? Is it possible to have a run away effect from eating a few large meals in a row, leading to less feeling of satiety?"
] | [
false
] | [deleted] | [
"Appetite and satiety have far less to do with gastric expansion than you might think. There are two deep-brain structures in the hypothalamus that seem to govern a large proportion of appetite and satiety. The lateral hypothalamus is the structure that fires when you're hungry and eating, but after you eat for a w... | [
"You can't simply eat your back to your old stomach size. Gastric surgery (for the purpose of weight-loss) involves either bypassing parts of intestine or removing part of the stomach entirely. While it is true that perhaps 25% of patients will experience weight regain staring 1-2 years after surgery, they will sti... | [
"The stomach is designed (and by designed I mean molded through natural selection) to constantly expand and contract as food enters and leaves. The stomach expanding is just one of the many signals that tells the brain it's time to stop. The stomach will only remain expanded as long as there is large amounts of foo... |
[
"I hear news about about coral reef loss all the time, but are we seeing any coral growth in new/existing areas?"
] | [
false
] | [deleted] | [
"Coral reefs take a very, very long time to form. Think thousands of years. They also mostly require clear, shallow water and they are very sensitive to temperature. So the reefs we ",
"know about",
" are a fairly comprehensive list. The best strategy thus far has been to introduce ",
"farmed coral",
" into... | [
"I did a little paper on this a few years back, it was pretty basic but I learnt a few things on this subject. The oceans are a massive carbon dioxide sink and much of the carbon dioxide in the air is sucked up by them, and as the carbon dioxide increases in the atmosphere more and more is deposited into the oceans... | [
"I did a little paper on this a few years back, it was pretty basic but I learnt a few things on this subject. The oceans are a massive carbon dioxide sink and much of the carbon dioxide in the air is sucked up by them, and as the carbon dioxide increases in the atmosphere more and more is deposited into the oceans... |
[
"Why do people never forget how to ride a bike once they've learned?"
] | [
false
] | null | [
"The fear of falling is the main reason why it's hard to learn in the first place. You need a certain amount of speed to keep it upright, but a higher speed = a more painful experience if you fall. So the tendency is to want to start off slowly, causing a wobbly ride. The intricate details of which gear to use, how... | [
"This guy forgot how.",
" Although that's because he retrained on a backwards bike. I don't know what it would take from just not riding it."
] | [
"As a few people have commented, you ",
" forget how to ride a bike. You can train yourself out of it, or you can just let the knowledge lapse from disuse (it happened to me). So I think we need to back up and start by asking, why do people ",
" you can never forget how to ride a bike once you've learned? Is th... |
[
"Would it be possible to create a type of artificial air that is heavier than natural air and use it to create a breathable atmosphere on the moon?"
] | [
false
] | null | [
"No. ",
"Earth's atmosphere",
" (which we can breathe) is approximately 78% nitrogen and 21% oxygen (and 1% other gases). The essential component which we need is Oxygen, Nitrogen is essentially chemically inert. Oxygen and Nitrogen are both diatomic molecules, and so they weigh about the same at the same press... | [
"When did obama die/leave the white house?"
] | [
"No. Like hal2k1 mentioned mixing due to density may be a problem, although if there is sufficient wind it may not be. The real problem is that the moon's gravity is not strong enough to retain oxygen due to heating and solar wind imparting enough kinetic energy to achieve escape velocity. The result is that, even ... |
[
"What is happening on the cellular level when you rub lotion into your skin, and why is it good for you?"
] | [
false
] | null | [
"When you say lotion you can mean one of a few different things. Products known as ",
"emollients",
" are lipid (fat) heavy solutions that restore barrier function to disrupted skin. Another sub-class of \"lotions\" are humectants, which hydrate the skin by trapping water. Generally speaking, the lotion (vehicl... | [
"NO MORE HOSE JOKES. Please. "
] | [
"There's also been some great research showing that lotions containing nanoparticles are able to get through the skin and move into the blood stream. If there's any interest, check out the work done in the ",
"DeLouise Lab",
" at the University of Rochester."
] |
[
"When it's bright out, and your pupils constrict, why isn't our field of vision reduced?"
] | [
false
] | because there is a smaller 'hole' for it to enter the eye through | [
"I'm an engineer, not a biologist, but I believe that the optics of an eye are close enough to the optics of a camera to give a good answer. The aperture diameter of a camera determines the amount of light it receives and its ",
"depth of field",
", but not the field of vision (well, not how you're thinking).",... | [
"For most pupil sizes, the visual field is not affected, for the reasons listed in the other comments.",
"But when the pupil gets smaller than 3mm, it does have negative impact on the threshold visual field. The threshold visual field is a way of measuring \"how bright/big does a stimulus have to be for someone ... | [
"The image of what you see is projected on to the back of the eyeball, at the retina. All the light from any point you are looking that passes through any part of the lens is focused onto a point on the retina. The size of the pupil just affects the brightness of the point."
] |
[
"When we squint our eyes we tend to see things better. Why?"
] | [
false
] | [deleted] | [
"Squinting our eyes increases ",
"Depth of Field.",
" That is the range which things are acceptably in focus. You get the same effect when you look through a pinhole in a piece of paper.",
"It's also why you get eyestrain in a dimly lit environment. Your iris is wide open and your lens has to work extra hard ... | [
"Agree with comments above, but I also would like to add a quick side note. Ophthalmologists and Optometrists use this a quick and dirty test to assess blurry vision. If you come into my office complaining of blurry vision, I take your visual acuity twice. Once normally, then once with a pinhole covering your visio... | [
"When an individual is squinting or looking through a pinhole, he is eliminating or reducing refractive errors. Most of the light will be passing through the center of the cornea and lens as straight light rays parallel to the axial length, with most refraction being eliminated from the equation altogether."
] |
[
"Are Animals able to reflect themselves ?"
] | [
false
] | [deleted] | [
"Yes and no, animals have genes that tell them what to do, how to do it, and when to do it. Using your bee example, bees have genes that tell them things, such as how to communicate and obey their queen. So I would have to say YES they did build hexagons but that they PROBABLY WERE perfect hexagons. This shape prob... | [
"I'm afraid I need some clarification. What do you mean by reflect themselves? Are you referring to assessing the quality of their work and trying to do it better next time?",
"I think biology is science too. Don't worry, this is the right place to ask. "
] | [
"Yes, built a square comb, see it wont work well and next time try another form. And on top of all, give this to the next generation of bees. *bee-o-logy "
] |
[
"Confused about the energy release of hydrogen through fusion"
] | [
false
] | [deleted] | [
"You need to account for the fact that helium is lighter than 2 protons + 2 neutrons, due to its ",
"nuclear binding energy",
". You also have to be careful with the masses of electrons; 1 H1 is not the same as 1 p, and there are also positrons produced which annihilate some of the electrons.",
"You want (4 ... | [
"E = (H x 6 - He x 4 - p x 2)c2",
"I'm confused by that step. Can you explain how you got there?",
"The stages of nuclear fusion from hydrogen to helium are not that simple.",
"Check out the full proton-proton chain ",
"http://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_reaction"
] | [
"Yes. The whole point behind fusion is that heavier elements do not have a mass of the sum of their individual nucleons - the change in mass is where the fusion energy comes from."
] |
[
"Mirrors and angle of reflection"
] | [
false
] | At the atomic level the surface of a mirror (or prism) must look something like a bunch of overlapping spheres (of electromagnetic forces?) lying the same plane. In comes a photon from some direction, why does it reflect along the normal of the plane rather than being scattered somewhat randomly. The only thing I can c... | [
"Disclaimer: Undergrad physics major currently taking electrodynamics.",
"The specific frequency and therefore the wavelength of the wave is important for reflection.",
"In conductive materials, light will excite electrical oscillations in the material. These oscillations absorbed the energy of the wave and re-... | [
"If a photon is going to be absorbed and then emitted the configuration of the electromagnetic fields must somehow \"remember\" the angle of incidence and compute a reflection angle. That seems plausible if the the photon interacts with many atoms. However my understanding is that a photon dances with a single elec... | [
"To clarify, when light enters a medium it causes charged particles to vibrate (regardless if it is an electron or not). If their exists a mode of vibration in the material near the frequency of light, then most of the energy is absorbed and the material is not transparent to that frequency of light. The material d... |
[
"How do unhatched chicks breath through the shell?"
] | [
false
] | [deleted] | [
"The short answer is the egg shell is permeable for O2 (there are little pores that allow gas exchange.) ",
"Gas exchange in and out of the shell is the least interesting part though (how does the chick breathe without lungs?)",
"https://www.npr.org/2018/04/17/602860545/how-birds-to-be-get-oxygen-inside-eggs"
] | [
"Good question! If you remove the eggs, this can actually cause the birds to try and nest again. Nest get found by predators, destroyed, etc, if it’s early enough in the season and they lose the nest, they just try again. If you leave the eggs, they’ll keep sitting on them and they just never develop, they’re basic... | [
"The eggs do need a certain amount of humidity. If they get too dry that is bad as well. However, you aren't too far off about too much being bad. One common method for controlling populations of geese (I think our local zoo did it when the peacocks really got out of control) is removing the eggs from the nest, dip... |
[
"Why is the same side of the moon always facing Earth? Is this common among satellites?"
] | [
false
] | I know that it's called tidal locking when an orbiting satellite always shows the same side. Is Earth's moon unique in its behavior? Or is tidal locking just a common side effect of orbit? | [
"Tidal locking is a common side effect of orbit. In fact, the tidal forces on the Earth exerted by the moon are slowing the rotation of the Earth, causing the days to get longer (by a very small amount). Eventually, the Earth will be tidally locked with the moon (the moon will then be in geosynchronous orbit).",
... | [
"Yes, planets that are close to their star should be tidally locked (or in some other spin-orbit resonance, like how Mercury rotates three times for every two times it orbits the Sun)."
] | [
"Since there are tidal forces from the sun, would if be possible for a planet to lock itself into place (one side permanent daylight, the other night)?"
] |
[
"What would be the environmental impact of eradicating mosquitoes entirely?"
] | [
false
] | null | [
"According to ",
"this article",
", there are few obvious downsides, since the ecological niche occupied by mosquitos would be filled by other species. ",
"Ultimately, there seem to be few things that mosquitoes do that other organisms can't do just as well — except perhaps for one. They are lethally efficien... | [
"What do mosquito larvae eat before they grow large enough to fly around sucking blood?"
] | [
"Worth noting that male mosquitoes never eat blood - it's only the ladies that do, and only for reproduction. Otherwise they all eat nectar. "
] |
[
"Do animals get jetlag the way humans do? Do they recover in the same way and in the same time period?"
] | [
false
] | null | [
"This",
" article highlights the fact that our circadian rhythms are programmed centrally by light - and that it involves ",
"epigenetic",
" changes. The feeling of jet lag is a disruption in the light cycle, and returning to a normal light-dark cycle is needed to \"fix\" our internal clocks/relieve jet lag."... | [
"My god you just asked a mouthful - that could easily be the topic of someone's doctoral dissertation.",
"I have no idea, maybe someone else will know. Definitely an interesting question but I don't know any data about it."
] | [
"So which animals are similar(where on the evolutionary tree did this start and who is on it)?, and for the ones that are not, how do they experience jetlag?",
"Edit: Spelling."
] |
[
"Can hyenas become domesticated through selective breeding and eugenics?"
] | [
false
] | null | [
"Just a point of information: Hyenas aren't canines, they're feliformia (cat like). ",
"http://en.wikipedia.org/wiki/Feliformia"
] | [
"Damn, I keep confusing them with canines because of their look. Editing the text now."
] | [
"Given enough time, couldn't any animal be domesticated using the methods you mentioned? I am being naive there?",
"It is possible to keep hyenas as pets in their current state - I'm sure we're all seen the pictures floating around on the internets. I've heard that they will be quite obedient while they see you a... |
[
"Of what significance is an angled frame of reference in spacetime?"
] | [
false
] | I once read that for objects traveling near c, their frame of reference becomes angled such that what is considered the future for a stationary object becomes "now" in front of a moving object. Are these slices only used to determine the order in which event cones affect the moving object, or can they further be used e... | [
"It sounds like you're referring to Minkowski diagrams. They're just illustrations, and they do not preserve lengths or right angles. That's why they make things look stretched and angled.",
"and change in mass?",
"That does not happen. It was once fashionable to teach it that way even though it's incorrect, bu... | [
"I'm not quite sure I understand your question, but anything which determines the order which events are perceived will also have to predict time dilation and such."
] | [
"They can be used to explain time dilation and length contraction. You wouldn't ",
" to, because representing those effects on a 2D representation of a Euclidean projection of the actual geometry is difficult, but you ",
".",
"Change in mass doesn't meaningfully happen in general, and nothing in physics shows... |
[
"It seems to be an established fact that our planet is undergoing climate changes, but is it conclusively proven that this is due to human activity?"
] | [
false
] | In the media there has been numerous reports about how our environment is changing, which seems evident and indisputable. I have not ever seen any evidence to suggest that this was caused by human activity and in fact a few months ago it was suggested that we could be headed towards a small ice age because the suns act... | [
"I don't know how you could have ",
" the evidence suggesting climate change was partly caused by human activity, unless you've just been ignoring all scientific articles about it for the past 20 years.",
"Currently people are consuming about ",
"3 cubic miles of oil equivalent per year",
", which adds abou... | [
"Oh, nice, our most active climate misinformer is back from ",
"/r/climateskeptics",
" with yet another misleading wall of text.",
"To keep it short, ",
"here's",
" our most recent (and link to previous) \"discussion\" showing the multiple flaws in your arguments.",
"A short answer to your recurring but... | [
"It doesn't. The temperature trend for the AMO (if it is indeed a real oscillation, which is not yet certain) is flat, while temperatures have been increasing.",
"You really do persist in that misrepresentation, don't you? Do you understand what a linear trend superimposed on a sine wave means? Compare ",
"temp... |
[
"By my understanding of Special Relativity going really fast makes an object super massive and gives it a strong gravitational pull. How close to the speed of light can we realistically propel an object and would going at that speed cause the object to act like a \"pseudo black hole?\""
] | [
false
] | And if going at that speed did cause an object to act like a "pseudo black hole" would the object be able to significantly disrupt the orbiting bodies of any solar systems it passes? | [
"You are going at .99999c right now relative to cosmic muons.",
"Velocities are not Lorenz invariable, thus they are only defined relative to a frame of reference.",
"Plus, the increasing of mass when approaching c is an outdated model.\nNowadays, it is believed that the kinetic energy, not the mass increases. ... | [
"\"The kinetic energy increases when you accelerate an object.\"",
"I think that's kind of obvious...",
"Regardless, your answer doesn't really give me much information I know how to think about. What would happen to a planet if an object going as fast as we can realistically propel an object were to pass close... | [
"The constancy of light causes the decrease of acceleration.",
"If you are interested in the math, ",
"here",
" is a derivation of the Lorentz Transformations. "
] |
[
"Why is it that there is such dense deposits of things like gold in certain regions of the world but others there isn’t in other places?"
] | [
false
] | null | [
"Impact events have indeed directly formed some major ore deposits, as well as generating large crustal disturbances and participated in at least one major extinction. There are other, more common geological processes which also lead to formation of ore deposits though, and it's perhaps worth pointing out that thos... | [
"Various elements of economic importance are concentrated by geological processes, these usually involve superheated fluids circulating within the crust. This can cause certain elements to become dissolved within the fluid, if this happens continually over a wide area and then conditions change and the fluid dumps ... | [
"I dont know about all areas, but some rich metal deposits are caused by massive meteor impacts. ",
"I read about a Canadian city called sudbury, which was basically founded for mining. ",
"A massive meteor impacted millions of years ago, and melted a large amount of the ground. ",
"This allowed the dense mat... |
[
"What happens to alpha radiation once it hits a barrier it can't cross?"
] | [
false
] | null | [
"It slows down, grabs onto some electrons, and jus becomes a normal helium atom."
] | [
"So it's neutralised for lack of a better word? There's no more radiation because it's no longer unstable?"
] | [
"Neutralized, yes. Alpha particles are never unstable, but once it loses most of its energy, it's no longer ionizing radiation."
] |
[
"Can things truly go in a \"straight line\" when traveling in space?"
] | [
false
] | [deleted] | [
"According to the general theory of relativity, these orbits ",
" straight lines (geodesics). A cannonball following a ballistic trajectory is also traveling along a line-of-shortest-distance through spacetime."
] | [
"No. The trajectory of the cannonball, which looks parabolic from the perspective of an observer forced upwards by the ground, is a straight world-line. Space is curved such that its path is straight. It is the electromagnetic force from the ground (upon impact) that wrenches the cannonball from its true path. Your... | [
"No. The trajectory of the cannonball, which looks parabolic from the perspective of an observer forced upwards by the ground, is a straight world-line. Space is curved such that its path is straight. It is the electromagnetic force from the ground (upon impact) that wrenches the cannonball from its true path. Your... |
[
"When we learn a new language are we learning it differently to how we learn our first language (instead of adding meaning to words, translating words that we already know into the new language)?"
] | [
false
] | null | [
"While most people around me were studying child language acquisition, I took the road less travelled and studied adult language acquisition (at this point, most scholarly studies in this field are mine, thankyouverymuch).",
"The first part of the answer is we all learn differently. And a second (or third or seve... | [
"Amazing response!\nI'm fluent in Spanish and English, and I'm trying to learn Chinese. This post hit home. After I read about the \"extrapolating\" vs. \"translating\", I knew this was relevant. I find that when I see a new word in English or Spanish, it's not a big deal. I can understand even if some words in the... | [
"very interesting read thankyou, I fully understand the mechanism you describe, even though I speak only one language I learned how to read Morse code (at a 'fluent' speed), there is a step where you just hear the sound and the process is automatic you hear ._ and you write down \"a\", it is not long that words and... |
[
"Trying to teach high school science students about rockets! Anybody experience with water rockets, help us out."
] | [
false
] | [deleted] | [
"I used to get the sport water bottles with the pop top, fill them 3/4 full with water, drop in a piece of dry ice, and wait for it. The pressure builds up as the co2 goes to a gas and then the top pops open and water propels the bottle across the room. This is probably not the safest for school, as I have seen a f... | [
"A coke and mentos rocket would be a much safer alternative."
] | [
"http://i.imgur.com/uJFsc.png",
"Basically it is a piece of wood with a hole in it for a copper tube to go thru. This was then fed thru the center of a big black rubber cork. There were 4 eyeleted screws in the wood around the cork in such a way that a \"tuning fork\" looking metal thing could slide thru the eyle... |
[
"What's causing the strange ice behavior in this video?"
] | [
false
] | via : | [
"Hi there, since this is a crosspost linked to a very popular video on Reddit at the moment, I figured I should welcome some redditors unfamiliar with AskScience.",
"Welcome to AskScience! We have a few specific rules on this subreddit, you can find them on the sidebar that way --->",
"In a nutshell, please do... | [
"The water, under pressure from the weight of the ice above it, is shooting out of cracks in the ice, and the air temp is cold enough to instantly freeze the water. The new ice lands on top of the other ice, increasing the weight of ice and therefore the water pressure. The water jets out and freezes, and the cycle... | [
"This is not true. This is simply candle ice that is being pushed onto shore/piling up due to the movement of the ice behind it. I assume the ice movement is due to wind. "
] |
[
"Cryptography: Why can't a one-time pad be half as long as the plaintext?"
] | [
false
] | [deleted] | [
"The key to a one-time pad is to have a perfectly random key that is never used again. The key your proposing is no longer random, if I guess the original key (0101) I now have your new key (00110011). In practice, what you would do is use two different keys to encrypt the message such that the length of the two ke... | [
"Actually, a 'true' one time pad cannot even be brute forced, since if it was truly random, then your output is truly random, and as you brute force through every possible combination, -every- possible clear text will also appear, with no way of knowing which one is correct. "
] | [
"It's ",
" easier to guess a key of length n than a key of length 2*n. We're talking computers and GPUs and devices that can do a trillion operations in the time it takes you to (literally) blink."
] |
[
"What mechanism dictates that a particular medications will reach the correct brain region and cells without targeting other brain regions?"
] | [
false
] | How can we be so exact in target and location with medication? For example: If a particular substance binds NMDA receptors then how do we control the dynamics so that it binds to the NMDA receptors in the amygdala and not the NMDA receptors of prefrontal cortex? | [
"Nothing. If the drug crosses the blood brain barrier into the CNS then a drug will be available to all receptors. In fact, it'll be distributed through the whole body where the organs like the liver (mainly) and kidneys will metabolism it. Depending on how fat soluble it is (like thc) it'll be distributed in body ... | [
"Unfortunately drugs aren't as exact as you make them. A perfect drug would have no secondary effect; if they result in other than the intended effect, it is because of unintended interactions with other receptors.",
"Secondary effects may also occur due to an unwanted distribution of the drug. First generation a... | [
"Then what causes a particular group of neurons of the brain to respond to a drug more so than another group of neurons? Receptor density on a given neuron region? ",
"Sorry if I am misunderstanding. ",
"Thanks"
] |
[
"Could it be theoretically possible to use an atom to store more than one bit of information by reading and rewriting the electron orbital configuations?"
] | [
false
] | null | [
"No. The electrons will always fall back to the lowest energy state."
] | [
"When you ask how an \"atom\" can store information, you have to consider it as a system. The definition of information requires numbering the meaningful number of distinguishable states. This necessitates considering an atom as part of a system.",
"Once you have accepted that, you can use an atom to store all ki... | [
"Could qubits aid in classical computers or are they only applicable to quantum computation?"
] |
[
"How can a material remain radioactive after it has been exposed to radiation?"
] | [
false
] | I was watching TV today and the topic of the Fukushima nuclear accident was brought up on the news and the reporter had mentioned "radioactive water" which got that way from exposure to radiation from the Fukushima nuclear plant. I just wanted to know how a substance, such as water, can remain radioactive just because ... | [
"It's important to recognize the difference between radiation, and radioactive material.",
"Radiation is the particles and waves which are emitted, which can be ionizing or non-ionizing. ",
"Radioactive materials are atoms which are unstable and emit radiation.",
"Some types of radiation can cause other mater... | [
"As was said, the water is merely contaminated with radioactive materials, but some elements can become radioactive through neutron activation, from being exposed to a neutron flux in a nuclear reactor or explosion . \n",
"http://en.wikipedia.org/wiki/Neutron_activation"
] | [
"Devil's advocate question: then why do they store all the contaminated water instead of just filtering it? "
] |
[
"How is it possible that neanderthals bred with humans?"
] | [
false
] | I happened across this which says that neanderthals bred with humans. I had thought that when species bred with other species then the offspring were unviable or sterile, but the article suggests the dna still exists within the human population? edit.. link to the original | [
"This is precisely why they're often classified as a subspecies (",
" to our ",
") rather than a separate species.",
"Interspecific hybrids",
" (breeding between two different species) is sort of a fuzzier matter than the textbook definition of species lets on. It can certainly ",
" for two closely relat... | [
"You have to keep in mind that the whole idea of a \"species\" is an artificial construct that humans have created to try to describe living things in the natural world. People spend entire careers trying to determine the distinctions between recognized species, or describing new ones. If you get down to single-c... | [
"Not always. Different degrees of hybrid have different success breeding together. Humans and neanderthals were very, very similar. Female Yak-Buffalo hybrids are fertile."
] |
[
"X-Ray crystallography"
] | [
false
] | Is it fair to say, "in x-ray crystallography, we're looking at the x-ray shadows of atomic radii in crystals, in the same way that you're looking at the x-ray shadows of atomic radii in bones when you get an x-ray at the doctor's office"? Further- can anyone give me an easily understood demonstration of x-ray crystallo... | [
"While I'm going to wait for one of our x-ray crystallography experts to give you a detailed answer, I'll start off with this:",
"\"in x-ray crystallography, we're looking at the x-ray shadows of atomic radii in crystals, in the same way that you're looking at the x-ray shadows of atomic radii in bones when you g... | [
"They are not the same thing. Bear with me:",
"First, if we could visualize proteins with some kind of microscope, we could. However, light or electron microscropes cannot directly see things at that resolution. Therefore, we must use physics.",
"You know when you shine light through a diamond, and it scatters?... | [
"Cool. So since the section where we teach 'em optics, wave particle duality et cetera comes much later, I'm probably starting to exit the remit of this class, here. I suppose I'll wave my hands about x-ray diffraction, and teach it in detail next year after they've had Optics.",
"Thanks :)"
] |
[
"A common question about Horava's (and others') Theory of Everything"
] | [
false
] | I recently read about Horava's modification of General Relativity that seems to be a good candidate for a Theory of Everything: And the same question popped up in my mind that I also have about every other serious attempt at a ToE: Does Horava's theory or any other serious attempt at a Theory of Everything (loop quantu... | [
"I don't know much about Horava's theory, but string theory still has the speed of light as the speed limit. There are some theories (mentioned in ",
"the bottom section",
") that include a speed of light that is energy dependent."
] | [
"Experimentally it is well established the c is the local speed limit of matter with positive mass (and the speed that massless particles travel at). FTL travel could be achieved by having wormholes, but most do not believe these solutions to GR could be macroscopic or stable. ",
"I don't feel like reading into ... | [
"Makes me want to learn the details of this stuff just so I can understand it. What's the point of being alive if not to understand the framework by which existence is possible."
] |
[
"Simple question about Aldosterone, pressure, and volume in the kidneys"
] | [
false
] | One the effects of aldosterone is The overall effect of aldosterone is to increase reabsorption of ions and water in the kidney -- ( ) However, Boyle's law says that pressure and volume are inversely proportional, so my question is: how does it can it possible that both pressure and volume to rise? | [
"Ahhh, this is a good question!",
"The reason lies in the fact that the body's circulatory system is half elastic really. If you do not increase the size of the system, and push more volume into that system, you will increase the pressure. It is by this active process that the blood pressure and volume are incr... | [
"No, it simply makes the arterioles constrict. The issue here is that you're trying to relate a law about gases to liquids. ",
"By constricting the arterioles it makes the SVR (Systemic Vascular Resistance) higher, and the systolic (active or higher portion) of the blood pressure higher. Putting more volume in... | [
"Not that I can find. I think there are too many variables when considering solids or liquids, since both can contain a volume of gas inside their structure, and thus won't necessarily act predictably of their own according.",
"Not to mention that density and compressability varies wildly from substance to subst... |
[
"Geography: What would the climate of the various parts of Pangea have been like? Especially the dry heartland?"
] | [
false
] | null | [
"Relevant: ",
"http://www.reddit.com/r/askscience/comments/1dbcoy/panthalassa_was_the_giant_planet_wide_ocean/"
] | [
"Twas modelled in the following studies (below), although there are some discrepancies between inferred climate and in-situ data from observed palynological assemblages.",
"Overall and unsurprisingly: large parst of gondwana and Laurussia had quite arid desertic climate with upper average dayly temps in the 30 to... | [
"unless they were migratory I suppose, as the Buffalo or the cariboo. Although they could have been migratory whether they were warm or cold blooded, now that I think of it."
] |
[
"Quantum Entanglement, what about quantum physics makes it work?"
] | [
false
] | null | [
"The ansible was based off of the misconception that most people have about entanglement. That somehow one particle reaches out across space and touches the other particle and tells it how to be.",
"The reality is a bit more simple. Suppose you have a particle with no angular momentum. It decays into two particle... | [
"It's not that they're \"invisible gears.\" It's that the two particles are each ",
" of one system. That system must have net angular momentum zero (in my specific case example). But you have no information about which particle points which way. There are two ways to interpret this:",
"The first way is kind of... | [
"at a very very rough first glance: yes. it seems that they're saying maybe somehow somewhere we'll get access to those hidden variables and use them to send ftl messages. Well ftl messaging gets wonky with observers moving relative to each other, because it doesn't keep time ordering correct. It can be future dire... |
[
"Say we built an unbroken train around the Equator that could reach relativistic speeds. How does it appear to an outside observer as it approaches light speed?"
] | [
false
] | [deleted] | [
"I believe you have proposed something very similar to the ",
"Ehrenfest Paradox",
". The train would have to break at a certain velocity because the relativistic effects would stretch it faster than the speed of sound in the train could respond."
] | [
"Oooo, I like this one. Let's paint it yellow. Then, when it approaches relativistic speeds its color will shift out of the visual spectrum and it disappears."
] | [
"the relativistic effects would stretch it faster than the speed of sound in the train could respond.",
"Isn't the rate at which the relativistic effects stretch it dependent on the rate of acceleration? If so, couldn't you just make sure to accelerate it at a low enough rate so that it didn't stretch faster than... |
[
"Why do people blame vaccines for links to Autism?"
] | [
false
] | I guess I was wondering what the actual argument used against vaccines was, and what evidence, if any can back it up? | [
"There was a 1998 study published in the Lancet (which has since been ",
"retracted",
") that is commonly cited. There have been some other correlations identified, but prevailing medical evidence right now suggests that vaccinations are safe. "
] | [
"The above is absolutely correct. An additional factor is that the diagnosis for autism cannot be reliably made until the child is a toddler (Wikipedia has 14 mths to 3 years and I don't know enough to narrow down the age range).",
"What that means is that the parent will have a child who may be acting a bit str... | [
"The fraudulent study was by ",
"Andrew Wakefield",
"is a British former surgeon and medical researcher, known as an advocate for the discredited claim that there is a link between the measles, mumps and rubella (MMR) vaccine, autism and bowel disease, and for his fraudulent 1998 research paper in support of th... |
[
"Why is water boiled in power plants as opposed to other liquids?"
] | [
false
] | E.g those with lower boiling points. Surely this would mean less energy is required to cause evaporation and therefore generate electricity. | [
"Wouldn't the amount of energy harvested be the same regardless of the temperature of evaporation? In which case it doesn't matter which liquid is used, therefore engineers would use the cheapest available, water. "
] | [
"E.g those with lower boiling points.",
"Just the opposite!",
"The theoretical maximum ",
"efficiency of a heat engine",
" such as a generator is:",
"1 - T_c / T_h\n",
"where T_c is the cold reservoir and T_h is the hot reservoir. The cold reservoir in a power plant is typically ambient temperature (wa... | [
"Do you have a news article for this? There no way a plant fire and explosion with liquid sodium could be covered up without the press knowing."
] |
[
"What mechanical motion of the body can exert the theoretical maximum amount of force?"
] | [
false
] | For example: even though the swinging of a golf club makes a golf ball travel farther than kicking a soccer ball, is there really more force being exerted on the golf ball through the swinging motion? What motion (swinging, throwing, kicking, etc.) produces the most force? | [
"I'm also interested in how much average power produced during the clean movement by certain weightlifter, for ex:",
"http://www.youtube.com/watch?v=QPO0LuDxXUE",
" So I found this:",
"4786 watts for a 110 kg lifter.\n",
"http://www.livestrong.com/article/406603-olympic-weight-training-stats",
"Now compar... | [
"There's a difference here between force and power. Raw force is the same as \"what's the maximum weight one can lift\", and it would probably be either a squat in a smith machine or a leg press - i.e. something which uses large muscle groups and doesn't need much stabilizing. ",
"Power on the other hand is about... | [
"Discovery channel did a series on different martial arts kicks and their power, on iPod but just YouTube it, also Bruce lees side kick produced extreme amounts of power. Sorry I can't provide links :( \"martial art tricking\" artists also generate extreme power through their kicks. Though never have been tested as... |
[
"Is there a way to shield a magnetic force by placing something between two magnetic objects?"
] | [
false
] | Like if you had a magnet attracting an object, and you placed something between the magnet and the object, could you decrease the attractive force? | [
"Magnetic fields (forces are caused by magnetic fields) cannot be blocked, no. That is, there is no such thing as a magnetic insulator.",
"A major reason for this has to do with one of Maxwell's Equations, implying that there are no magnetic monopoles. That is, where as you can separate electric monopoles (positi... | [
"You can use materials with high magnetic permeability (Permalloy to name one), which more or less captures the magnetic field. This is however much more the case and effective for closed containers, that are sometimes stacked one into another like Matryoshka puppets..."
] | [
"Im not an expert but I’ve read that magnetic or electric fields can’t get any deeper than 100nm into superconducting things. (Meissner effect? I think?) so if you build a box out of superconducting material the inside should be free from magnetic or electric fields, if there is nothing inside that creates them?"
] |
[
"In the show Lie to Me, the main character has an ability to read faces. Is there any backing to that idea?"
] | [
false
] | null | [
"The idea is based off the theory that people produce \"microexpressions\" that last fractions of a second, with the assumption being that we can read these microexpressions subconsciously. However, further study found that professionals trained in microexpressions had no higher odds of success than random chance. ... | [
"This is a good answer.",
"As a social worker (msw) we are intensively trained in applied communication. If there's no incongruence between observable actions, stated actions, mood and affect, then there's no way to tell if someone is lying. This is why it can be very important to have collaterals as sources (fam... | [
"University Psychology Professor here (33 years).",
"Nope. No peer reviewed support for determining the veracity of statements a person makes by reading their faces. Doesn't work.",
"But also Lie Detectors are also pure theater. Cannot be used in US courts, no validity. Used as an interrogation tool."
] |
[
"Radiocarbon Dating, How does one calculate what the original amount of carbon was?"
] | [
false
] | My understanding of Radiocarbon Dating is pretty basic but from what I know you take find the amount of carbon-14 in the sample and use its half-life to calculate the original amount of carbon was. What I don't understand is that if one uses the half-life to calculate, you can keep doubling that to infinity. How do sci... | [
"C-14 is formed in the upper atmosphere. It reacts with oxygen to form CO2, and get distributed throughout the ecosystem. So long as an organism continues to taking in carbon from its environment, its C-14 \"supply\" will be continuously refreshed, and the ratio between C-14 and regular carbon (C-12) will remain ... | [
"This is right. I'm commenting just to add ",
"this",
" image to accompany your explanation.",
"Also, I want to highlight the point that the Carbon-14/Carbon-12 ratio is fairly constant. That seems to be the point that OP missed. Since it is constant we already know the original ratio of what is being analyze... | [
"For the most part, yes, but there are some exceptions, like the Old Carbon problem.",
"Some aquatic organisms live near limestone, which slow leeches its carbon into the water. Since this will be very old carbon, the resulting ecosystem will be disproportionally C-14 deficient. "
] |
[
"How many diseases can we develop immunities for?"
] | [
false
] | I know that our immune system can essentially "remember" certain types of diseases to respond rapidly to them. Is there a limit to the number of diseases we can develop an immunity for? | [
"From a basic immunology point of view, humans can generate around 5 x 10",
" distinct antibodies (immunoglobulins) via the adaptive immune system that use VDJ recombination, Junctional Diversity and Somatic Hypermutation. Of course, not every combination will be successful, so people generally say around 10 bill... | [
"The compliment can be considered ",
" Compliment systems act to enhance immune responses, namely the antibodies and phagocytic cells.",
"The compliment can be subdivided, broadly speaking, into 3 pathways:",
"Alternate and Lectin pathways are mainly innate processes. ",
" pathway is activated when a protei... | [
"The innate immune system can wipe a microbe before triggering the adaptive immune system",
"Is part of the 'innate immune' compliment?"
] |
[
"How were heavier elements than iron created?"
] | [
false
] | null | [
"There are other nucleosynthetic processes, like the r-process, the s-process, and the p-process, which produce the heavier elements.",
"Here",
" is a table of the dominant production mechanism for each element."
] | [
"Hi! Doesn’t the explosion itself from the ensuing supernova create heavier elements as well?"
] | [
"Thank you! That does answer my question"
] |
[
"Can an ECG read voluntary muscle contraction ?"
] | [
false
] | From my understanding of how ECGs work, wouldn't an ecg reading pick up the action potential generated by skeletal muscle contraction in the same way it picks up the electrical impulse caused by the heart muscles ? | [
"Yes, it's called an EMG."
] | [
"An ECG does tend to have background noise from chest movement. To measure skeletal muscle contractions you would use an EMG. (Which can have surface leads like an ECG, or have standard leads which involve piercing the skin with a needle electrode and measuring nerve impulses directly from the muscle.)"
] | [
"Moving around a lot can definitely make an ECG harder to interpret. Even breathing can cause weird stuff on an ECG. Those are called \"artifacts,\" and whoever is interpreting the ECG has to figure out what to attribute it to. They'll always attempt to keep interference to a minimum, but there will be external inp... |
[
"Animals that camouflage themselves - how do they know?"
] | [
false
] | I feel like every question I ask here is derp, but here goes: I wonder about animals that camouflage easily - how aware are they that they are doing so? I assume the majority of the answer is that they evolved to be great at camouflage, but at any point is it known to be a conscious thing? Would an insect that resemble... | [
"A pink fish probably became pink because it probably hangs around pink coral a lot. After these fish evolves pink scales, some may have also hung around white coral, but those ones may have been more likely to be eaten. This promotes pink fish staying near pink coral.",
"As for whether or not it's conscious, we ... | [
"The octopus biologist ",
"on NPR",
" says that for octopi it's a delocalized system; the cells merely react to whatever they're near, without any coordination by the brain."
] | [
"I believe its all about survival. ",
"This video is a brief explanation on it",
". Imagine organisms as totally mindless, moving creatures that just eat, breed, and poop. The ones who have the 'safest' genes (Ie. Brown frog vs green frog in a brown swamp) will survive. They have no opinion in the matter. "
] |
[
"What is happening when a computer generates a random number? Are all RNG programs created equally? What makes an RNG better or worse?"
] | [
false
] | null | [
"RNGs use some algorithm to decide on a number which is based on the some previous number (or more over a large set of previous numbers) this is why all RNGs need a seed to get started, they need some way to generate the first letter. How you get that seed is a bit of a different discussion.",
"Now not all RNGs a... | [
"Some great answers here talking about what makes a good pseudo-RNG. I'm going to tell you about a bad one.",
"In Pokémon Red, Blue, and Yellow, when the player encounters a wild Pokémon, the species is determined by comparing a random value between 0 and 255 to a lookup table for the current location. For exampl... | [
"There's an implicit assumption in the vast majority of these answers that computer random number generators are ",
", and that random number generators must be implemented in ",
" unless you hook the computer up to a physical hardware random number generator.",
"That just isn't true, and in fact computers ha... |
[
"How many degrees of the FOV (in human sight) is color?"
] | [
false
] | Is color generally only "recorded" by the fovea? If not, how large is the area where we sense color in terms of size of cell structure, and more importantly: how many degrees of vision does this constitute? | [
"You get colour vision outside of the fovea, though how far out depends on what you're discriminating and how big it is. ",
"This article",
" cites work that finds colour discrimination as far as 90° out:",
"They found that subjects could detect chromatic bars out to at least 50° on the nasal horizontal merid... | [
"So my peripheral vision around my nose is not in color? "
] | [
"Right, chromatic bars is one thing, but has anyone tried with lower contrast material, like TV images, photos, or something similar?"
] |
[
"Does the amount of plastic in contact with a substance change how much chemicles are leached into that substance?"
] | [
false
] | So say I have an entirely plastic water pitcher and a mostly stainless steel water pitcher with a small plastic window; assuming the plastics are the same and that they leach something, would the water in the mostly stainless steel pitcher have less chemicals leeched into it? (Assuming same amount of water) | [
"Assuming you have a plastic that leaches chemicals, and the plastic does not run out of those chemicals, both bottles will experience the same amount of leaching. The end product will be water containing the same amount of leached chemicals. ",
"However, the rate of leaching will be much faster if the fully plas... | [
"The concentrations would only be the same at equilibrium if the amount of leached compound was insignificant compared to the total concentration of whatever chemical is being leached from the plastic, though. Eventually that assumption would no longer hold, and more of the leeched compound would be present in the ... | [
"Yes, I made clear that assumption in my comment. "
] |
[
"Energy of a wave is proportional to its amplitude. Energy of a photon is proportional to its frequency. How do those two propositions \"connect\"?"
] | [
false
] | [deleted] | [
"This was one of the big concepts in the early days of quantum mechanics. You might look up the story behind the photoelectric effect. The short version is that a light wave has total energy built up in discrete units (photons). You can think of the amplitude of a wave as being proportional to the number of photons... | [
"It may be worth adding that the classical limit of an electromagnetic wave requires a non-trivial limit. Others have already said that the energy is proportional to the number of photons N, but it is also proportional to ħ. It turns out that the classical limit involves taking ħ to zero and N to infinity such that... | [
"It doesn't make much sense to talk about the energy of an ideal classical wave, since ideal classical waves are infinite in extent and thus would have infinite energy. We can, however, talk about the energy per unit length of a classical wave. We can think of such a wave as a bunch of simple harmonic oscillators m... |
[
"Why are Birds sub-grouped under Reptiles and not in their own unique standalone class like Amphibians?"
] | [
false
] | null | [
"When we classify animals today we base their relationships on a shared evolutionary history. The taxa we name must consist of a common ancestor and all of the descendants of that common ancestor. It's called a monophyletic group. Any other type of group is arbitrarily excluding descendants and won't actually refle... | [
"Well, if you're not a morphologist, then it probably would seem like guesswork. It's...not. ",
"The vast majority of species that have existed are extinct. Morphology is a crucial component in the study of the relationships of life in earth, evolution, ecosystem change, you name it. "
] | [
"The latest research, based on a stem-caecilian from the Triassic, reconciles the fossil and molecular evidence by concluding ",
"lissamphibians are monophyletic",
"."
] |
[
"Can multiple planets exist in the same orbital path?"
] | [
false
] | My understanding of planetary formation is that a disc of material eventually coalesces in a singular object, but is it possible that it happens in one or more locations in the same orbit? Could there be two planets on opposite sides of a star orbiting in sync? Could earth have a twin behind the star that we never see? | [
"Some scientists theorize this is how we got our moon.",
"We had a planet close to the same orbital path that got a little too close one day and the two masses collided, on enveloping most of the other and the remains kept as our moon"
] | [
"Janus and Epimetheus share orbits around Saturn. Yes they are moons not planets, but it's not that hard to imagine planets doing the same. If it happened within our Solar System (and was independent of us evolving - it was) then it should have happened in many other places.",
"You do not need an exact match, ver... | [
"If there is a significant size difference between the planets, the only possible stable orbiting solution is at one of the ",
"Lagrange points",
". Jupiter has a collection of trojan asteroids at its L4 and L5 points. The opposite side of the star, you are referring to, is called the L3 point.",
"Because pro... |
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