title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Why do I struggle not to sink in water while everyone else I know floats with ease?"
] | [
false
] | null | [
"I'm guessing you're pretty skinny, then. Fat is less dense than water, muscle is denser than water. Thus, people with a low body fat percentage will have a harder time floating than those with a higher percentage.",
"EDIT: Holding in a big lungful of air will help, too, by the same principle."
] | [
"At any rate, I'd wager you're denser than your friends - either due to more muscle or less fat. You're certainly not alone in being unable to float.",
"And as for the \"black people can't swim\" thing, that's much more likely to be a socioeconomic issue than a biological issue."
] | [
"At any rate, I'd wager you're denser than your friends - either due to more muscle or less fat. You're certainly not alone in being unable to float.",
"And as for the \"black people can't swim\" thing, that's much more likely to be a socioeconomic issue than a biological issue."
] |
[
"Can a dying star extend its life-span by absorbing another star?"
] | [
false
] | Can a white dwarf star absorb another star to either extend its life as a white dwarf, or regenerate back to a red/yellow/blue star? Can a neutron star do the same? Or would the particles simply break down to neutrons? Would red giants shrink after absorbing a blue star, due to the new supply of hydrogen? Would they c... | [
"Most of the time when two white dwarfs merge they new star formed will be unstable and cross over the ",
"Chandrasekhar limit",
" the star will be heavy enough to support fusion again and begin to fuse carbon into neon. Runaway fusion will cause the star to go supernova. White dwarfs usually are around 0.5 to ... | [
"They would turn into a black hole. Also, astronomically speaking, 1,000,001 mph isn't really that fast. Its only about 1.4% the speed of light"
] | [
"What about 1,000,001 mph?"
] |
[
"Why is it advised to get rid of your toothbrush shortly after getting over a cold?"
] | [
false
] | If I'm correct, once you catch that specific virus, you become immune to it afterwards. What does it matter if it's on your toothbrush or not? | [
"The ADA does not advise this, if you're a normal healthy person.",
"Although there is insufficient clinical evidence to support that bacterial growth on toothbrushes will lead to specific adverse oral or systemic health effects, a common-sense approach is recommended for situations where patients may be at highe... | [
"Thanks! Just the answer I needed :)"
] | [
"Can you give us the context of this advice? You are right that you will be immune to the same cold virus as you just fought off the infection."
] |
[
"[Fluid dynamics] Why are turbulent fluids easier to travel through than still or calm fluids?"
] | [
false
] | I've noticed while surfing that when I paddle my hand moves much more easily through turbulent whitewater as compared to calm water. This makes it so that while I'm paddling in turbulent water I feel like my efforts are no where near as effective in moving me forward. I'm also aware of the fact that driving unsafely cl... | [
"I don't know about the effect of turbulence, but your observations with whitewater can be explained by the fact that whitewater contains a large percentage of air bubbles so there is less mass for your hand to push off of. Also, the reason drafting works is because the lead vehicle pulls some air forward with it a... | [
"I was under the impression that drafting in racing was more a function of reduced pressure drag rather than the air picking up an organized forward momentum. While the trailing car gets an advantage over the leading car, the leading car still experiences less drag than it would driving alone. ",
"More turbulence... | [
"In terms of liquids and gasses operating under the same mechanics, yes they do (for the most part, things get a little wacky under extremely high pressure or velocity). BUT, you're describing two different phenomena here. Drafting behind a large truck works because the truck is displacing large amounts of air, the... |
[
"Why is skipping with a rope so much more tiring than jumping up and down at the same rate?"
] | [
false
] | null | [
"You use more muscles and effort jumping rope than merely jumping up and down. You have to coordinate your form to the timing of the jump perfectly or you will fail but when jumping up and down you can let your form go to hell without consequence. You also use the muscles in your arms/wrists to move the rope while ... | [
"Thanks for this, that definitely makes sense. It might be a tangent, and don't worry if you don't know, but how significant is the mental focus / concentration aspect in terms of total energy used?",
"That's probably a wider question about the number of calories \"thinking\" uses actually, which I'm sure has bee... | [
"I'm sure once you jump enough rope you get the muscle memory to take most of the burden off your active thinking. Imagine cycling - learning is stressful trying to coordinate balance with peddling with destination and speed but once you cycle a bit you can hold entire conversations on your phone without thinking a... |
[
"Why were the initial images from Curiosity low quality?"
] | [
false
] | null | [
"Because it's small. The Rover sends a signal to the orbiter, and the orbiter can only transmit data to earth at 800 bits per second. That is incredibly slow."
] | [
"Any idea how long it will take to get some hi res stuff?"
] | [
"Please post ",
"in the official thread",
" in order to consolidate information."
] |
[
"Question about the recommended timing for child immunizations."
] | [
false
] | null | [
"StringOfLights, ",
"Thanks for your message. I did not feel like this post was in any way seeking medical advice. I was seeking a scientific answer to explain why babies are immunized at their scheduled times, to see if there were any studies done that suggested a greater effectiveness as opposed to waiting.",
... | [
"StringOfLights, ",
"Thanks for your message. I did not feel like this post was in any way seeking medical advice. I was seeking a scientific answer to explain why babies are immunized at their scheduled times, to see if there were any studies done that suggested a greater effectiveness as opposed to waiting.",
... | [
"Thanks for your reply. ",
"Just to give you a little background...my wife did graduated in Medical Laboratory Science. I don't believe she got a simplified version of what's going on in this case but I'll have to ask her. ",
"Would you be willing to provide a more in depth explanation for why \"It does not hol... |
[
"How do chargers with multiple voltage outputs decide what voltage to use and what does the internal circuitry look like?"
] | [
false
] | For example, the Nintendo switch changer has two voltage outputs (5V and 15V) and many USB type C laptop changers have four (5V, 9V, 15V, 20V) [Dell 65W type C charger, even the Amazon description has these outputs listed] Does the charger sense the battery voltage somehow or is there a communication protocol between t... | [
"Basically when you plug something in it turns on at 5V (because USB-C MUST work with 5V), and then the charger announces it's specs (I can do 5V @ 5A, 9V @ 5A, 15V at 5A, or 20V at 5A), and then the phone goes through the list and picks the one it wants (I want 9V, and I'll use 3A). When the charger receives the r... | [
"Great resource, thank you"
] | [
"There were some problems with peoples switches getting fried because of the use of a 3rd party dock and some proprietary standarts. Does that mean nintendo ignored the usb standart or is it just an extra mode it designed which the dock handled wrong?"
] |
[
"How different would the star constellation be around Alpha Centauri? Would we share any of the same noticeable constellations?"
] | [
false
] | [deleted] | [
"Even as most of the \"constellation stars\", ie. the one's visible with the naked eye, tend to be relatively close(*) to Sol, they're still, generally, tens, hundreds and even thousands of lightyears away. So, most of the stars' apparent positions would shift relatively little by the meager 4 ly jump from Sun to ... | [
"Most of the constellations would be nearly the same, but a few of the nearby stars would be out of place. For example, Sirius would be right next to Betelgeuse, and Cassiopeia would have a new first magnitude star (the Sun)."
] | [
"There are a few computer programs which let you move around the galaxy and have real data for nearby stars. Space Engine and Celestia to name two. Someone made a ",
"picture",
" using Celestia. Note in particular how Sirius has moved quite a bit, but it is one of the closest stars being only about 9 ly from th... |
[
"Marine biology in the movies"
] | [
false
] | How realistic is a film like The Life Aquatic with Steve Zissou? What is marine biology research like? Is it sailing the high seas taking a scuba dive every now and then like Jacques Cousteau, or is it closer to something like sitting in a lab looking at micro-orgranisms in the middle of once farm-land converted into... | [
"Fish Ecology is pretty cool. I get to electrocute streams and see what floats up to the top. As with any science, how much of your life is spent in the office versus in the field depends on what kind of job you end up getting, what kind of research you pursue, which grants you get, etc."
] | [
"it really varies. it all depends on what you are studying. im a marine biologist and i work about four hours from the nearest ocean, and spend most my day performing biochemical and molecular investigations on the enzymes expressed in crab gills. I have a friend studying crustacean ecology who is on a ship in the ... | [
"What exactly does electrocuting the stream tell you?"
] |
[
"I've yet to see a scientific explanation for the 'self' as far as conscious activity is concerned. Where does the conscious originate?"
] | [
false
] | null | [
"This question has been removed because it is highly speculative in nature. Exceedingly imaginary hypotheticals or questions that cannot be confidently answered with any available data often invite non-scientific speculations.",
"For more information regarding this and similar issues, please see the ",
"FAQ.",
... | [
"I'm sorry, but I was under the impression that this was a community of scientists and holders of knowledge, people wanting to discuss and teach and learn. Doesn't it make more sense to take care of any speculative posts instead of shutting down my legitimate question like that?"
] | [
"We do take care of speculative posts... in ",
"/r/AskScienceDiscussion",
". That's why the sub was created."
] |
[
"AskScience AMA Series: We are scientists on the OSIRIS-REx mission, NASA's first mission to collect a pristine sample of an asteroid to return to Earth for future study. The first sample collection attempt is October 20. Ask us anything!"
] | [
false
] | If you are traveling over 200 million miles to snag a sample of an asteroid, you want to make sure it's worth it. The following scientists are part of the OSIRIS-REx mission - NASA's first mission to collect a sample of an asteroid and return it to Earth. They have just published a collection of papers that confirm tha... | [
"I read that the probe will stay on the surface of the asteroid for less than a minute and collect samples by ejecting a high pressurized gas. Does this mean that the samples collected will be dust and small particles or pebbles? If this is the case, will those samples be enough for future study and analysis? \nTha... | [
"Yes, our sampling mechanism is designed to pick up small particles (think of pebbles no larger than a quarter's diameter!). We hope to gather a ",
" of 60 grams of sample (that's about a quarter-cup of packed brown sugar), but we expect to collect much more. Some of the sample analysis techniques we're using can... | [
"We chose the asteroid because it is a primitive and carbon-rich asteroid that can offer insight into our solar system's origins and other science questions... but it also needed to meet other criteria. For instance, it had to be a certain size and can't be rotating too fast. These are important for sampling. It al... |
[
"AskScience AMA Series: I'm Dr. Majdi Osman, an infectious diseases physician and Clinical Program Director at OpenBiome - a nonprofit stool bank that provides material for fecal transplants. Ask me anything!"
] | [
false
] | Today is World Microbiome Day! I'm here to talk about fecal transplants and microbiome research. Fecal transplants are exactly what they sound like - taking stool from a healthy donor, carefully screening it, and transplanting it into a patient. At OpenBiome, we provide material for fecal transplants to clinicians trea... | [
"How do you select people as poop donors? My daughter, a molecular biologist made reference to \"the man with the golden poop\", indicating most of the positive results from fecal transplants came from the donations of a single individual. When I donate blood, my blood is classified by type, rhesus factor, CMV neg... | [
"What are the most common causes for the need of fecal transplant? ",
"Also, can someone's body reject feces as it could with an organ transplant?"
] | [
"Thanks for the question! Our donor screening is quite rigorous and only 2.8% of people who apply make it to be a donor at OpenBiome. You can find what we screen for here ",
"https://www.openbiome.org/safety",
"It includes a clinical assessment with a clinician here at OpenBiome with over 200 questions, a blood... |
[
"What is the source of CO2 emitted by volcanos?"
] | [
false
] | Volcanos emit CO2, correct? What is the source of that CO2? Is it organic matter ( fossil fuels ) that get sucked into the volcanic system and effectively burned? Or are there non organic sources of CO2 beneath the surface of the earth? | [
"Yes, volcanoes emit CO2 along with a host of other gases, mostly water vapor, but also substantial amounts of [CO2 and SO2](en.wikipedia.org/wiki/Volcanic_gas). The primary source for CO2 in magmatic systems is not organic matter directly (so not hydrocarbons) but rather calcium carbonate (calcite / limestone). A ... | [
"It is also important to remember that the ",
"atmosphere has changed significantly over the course of earth history",
", so prior to life, there was a lot more CO2 in the atmosphere. Whether the carbon balance was such that there were immense deposits of calcite or just more in the atmosphere, I don't really k... | [
"Before life appeared on the Earth was there limestone? What I am not understanding is where did all the CO2 on the earth come from before the existence of life? "
] |
[
"Can someone shed some light on something I saw on Star Trek: TNG? It involves decompressing the shuttle bay and exposing Jordy and Dr. Crusher to open space."
] | [
false
] | They did this to put out a plasma fire and get rid of some volatile cargo that was about to explode. My question is this: what would have really happened to them if they had been exposed to the cold vacuum of open space? Sorry if this is a repost. | [
"his name is Geordi not Jordy"
] | [
"From the FAQ",
":",
"A human in vacuum can survive without permanent injury for about 30 seconds, according to NASA, provided that you don't try to hold your breath. It is estimated that you won't live beyond ~2 minutes, although this clearly hasn't been comprehensively studied, so it's tough to say. You do no... | [
"Also I'm sure the Enterprise D's medical bay would have different standards for what constitutes a permanent injury than NASA does."
] |
[
"How do you quantify relative amounts of DNA?"
] | [
false
] | I was recently reminded of an article where a lab in Canada claimed that around ~50% of subway chicken is actually soy. They claimed that quantification was done but amplifying DNA with PCR. I have a background in biology, neuroscience, micro biology, molecular bio. How do you use PCR to calculate these percentages? | [
"A variation of PCR known as qPCR (quantitative PCR) is used. Basically we perform PCR to amplify our selected DNA template to a point where we can measure the amount using various florescence methods, spectroscopy, or Nanodrop. ",
"From the point where we reach a certain threshold, we can determine the amount of... | [
"According to the methods described in the source, which are available on the last page of the PDF in the middle of the article, they didn't actually use qPCR for this (though they certainly could have). Instead, they just did two separate PCR amplifications using primers from chloroplast and vertebrate mitochondr... | [
"thanks"
] |
[
"I've got a chemistry question about Electron Configuration."
] | [
false
] | Why do most transition metals loose s-level electrons before p, d, or f. I asked my teacher and he didn't know. | [
"I believe it's because the s-level electron shell is the furthest from the center(the protons)."
] | [
"This is a really good question, and I just had a discussion with another grad student about the reason for this last night. There is no general answer that applies for all transition metals, but the short, hand wave-y answer is because it is the furthest away from the nucleus, or rather, that the 4s spends more t... | [
"Awesome, thanks for this, I hope the OP has access, I think J Chem Ed should be open to the public. I avoided mentioning \"core shielding\" by inner electrons, I don't really like the model equations that people come up with to estimate shielding. I'm not sure if the energy levels are ",
" upon addition of ele... |
[
"If all humans on earth were to die instantaneously, which man-made structure would hold it's form the longest?"
] | [
false
] | null | [
"The Pyramids perhaps, simply because stone wont corrode or break down easily and they are so massive that even erosion will just take a ",
" to wear them away. "
] | [
"And they've already proven their staying power over thousands of years"
] | [
"By design, long-term nuclear waste storage facilities:",
"https://en.wikipedia.org/wiki/Onkalo_spent_nuclear_fuel_repository"
] |
[
"Can pupils dialate (or constrict) from anticipation?"
] | [
false
] | null | [
"Yes! Your sympathetic autonomic nervous system gets your body ready for “flight or fight”, so if you sense or anticipate danger your body will slow down things like your bowels and speed things up like your heart... along with this your pupils will dilate! There is also the parasympathetic nervous system that does... | [
"Pupils can also dilate when looking at something attractive (person or a thing). That is often when professional poker players wear sunglasses, so the other players can't see their pupils when they get a good hand."
] | [
"You don’t want to be sending blood to the digestive tissues and using up oxygen and nutrients when you’re trying to survive. ",
"In anticipation of exertion (like running from a bear) your body increases sympathetic (fight or flight) stimulation over parasympathetic (rest and digest). This has many effects but o... |
[
"What can a soldier's helmet physically stop?"
] | [
false
] | null | [
"Short answer! Depends on the helmet.",
"Long Answer:",
"The US Army currently issues the Advanced Combat Helmet (ACH) to all of its soldiers. They're pretty cool with primarily kevlar construction. This kevlar protects against shrapnel and fragments, as well as providing penetration protection against small ca... | [
"The light weight one is bigger? "
] | [
"How is it being redesigmed to withstand that kind of caliber weapon? New materials or a better design?"
] |
[
"Are different kinds of animals mostly poisoned by the same things, and not poisoned by the same things, although there may be some things that only affect some kinds of animals? How about the same question with humans and animals? Why or why not?"
] | [
false
] | null | [
"Some molecules are for most of organisms toxic, because they are destroying the animals fundamental things like cell or bakteria or the the nerv system, by killing the them.",
"But there are some poisons that only kill smaller animals like the poisen in avocados",
"Sry for ths bad language I sm not a native sp... | [
"I'm not sure how this is relevant. If you're saying something can be toxic for a species, but then eventually they develop some physical characteristic where it's not toxic, I believe you're right that that sometimes happens.",
"But that's about what happens over time. But my question is not asking what happens ... | [
"Think about it like someone eating spicy food for the first time. ",
"You eat it, survive the pain and because you’re a freak you enjoy it so you keep eating it.....or you die. ",
"At first eating one hot Cheeto feels like Satan just pissed on your tongue. ",
"But keep eating spicy food once a day and eventu... |
[
"Do the constellations change/ look different from the Moon, Mars?"
] | [
false
] | null | [
"The constellations do not appear to change as the Earth orbits the Sun, and the Earth has an orbit that is 300 million km (186 million miles) across, so you can see that going to the Moon (400000 km away) or Mars (never more than 401 million km away) won't change what the constellations look like. ",
"In fact, y... | [
"Orion will look exactly the same from anywhere in the Solar System, though it might be oriented differently depending on which way the camera is oriented.",
"The ratio of 1 AU (the distance from Earth to the Sun) to 1 light year is about the same as 1 inch to 1 mile. So on a scale model of the galaxy where the n... | [
"Wow thanks for those pics. I'll be pouring over them in a bit. ",
"My common sense would dictate that nothing changes unles you are very far away, but when I was looking at a bunch of the recently released NASA Apollo pics, I noticed what looked like Orion, but it looked like the angles were wrong. "
] |
[
"Is it possible to make lasers for frequencies outside of the visible and near-visible range?"
] | [
false
] | [deleted] | [
"Yes. In fact, the ",
"maser",
" was invented before the laser - indeed, the first laser was called an \"optical maser\". There are also ",
"naturally occuring masers",
" in space.",
"X-ray lasers",
" exist, and during the Cold War the phycisist Edward Teller proposed the use of ",
"space-based thermo... | [
"http://www3.imperial.ac.uk/newsandeventspggrp/imperialcollege/newssummary/news_16-8-2012-10-15-30",
"These guys recently (2012) made a big breakthrough in the MASER (Microwave Amplification by Stimulated Emission of Radiation). ",
"Previous to his recent work, you had to cool the MASER down to extremely low te... | [
"Yes.\nIn fact the whole range down to 10nm is covered (*)",
"While there is no laser medium for all of those frequencies (especially beyond UV and in the farIR), people usually use non-linear crystals to convert frequencies into another. Those materials can absorb and re-emit in two-photon processes, i.e. absorb... |
[
"How does grounding (electrically) work?"
] | [
false
] | I've always imagined that it has something to do with the flow of the electricity and that you're sending the current (or part of it) into the "ground"...but I've always wanted a more full understanding. | [
"This might be a crude explanation compared to what others may be able to provide, but I'll give it a shot.",
"Short version: By grounding something it is connected to the Earth and current will flow from the object to the Earth until the object's electric potential is equal to that of the Earth. ",
"Analogous ... | [
"The Earth (a.k.a. ground) is slightly positive.",
"compared to what?"
] | [
"neutral"
] |
[
"If Jupiter is a gas giant, what sort of tangible surface does it have?"
] | [
false
] | null | [
"At first I thought there would be some sort of gas/liquind phase transition for a certain depth, but then ",
"Wiki has this",
" on the subject:\n\"...At this depth, the temperature is above the critical temperature, which for hydrogen is only 33 K[37] (see hydrogen). In this state, there are no distinct liquid... | [
"It's been theorized that there is some sort of solid metallic hydrogen core to Jupiter, or even a molten liquid core, which I guess could constitute a \"surface\". But at this point no one is really sure beyond theory.",
"The JUNO probe is supposed to reach Jupiter around 2016 and might help clear some things up... | [
"You're right! Jupiter's magnetosphere is formed the same way as Earth's, due to the motion of the outer core. Jupiter does have a core (most probably metallic hydrogen, which acts as an electric conductor), but it's exact nature is still up in the air. ",
"Is it liquid? Solid? Plasma? Not sure yet. Let's pick th... |
[
"How did people know that Australia or a large island in the southern hemisphere existed?"
] | [
false
] | Supposedly before Australia was found, and since the time of Aristotle, it had been thought that a large land mass existed in the Southern Hemisphere [named ] to counter-balance the European-Asian continents in the north. Was this based on any scientific evidence? I guess I don't understand the idea of a counterweight ... | [
"Yeah, that's all. They were big into balance back then."
] | [
"So they just thought a globe would look better/more-balanced if there was a landmass where Australia is? "
] | [
"Just a hunch:",
"http://en.wikipedia.org/wiki/Terra_Australis",
"Terra Australis (meaning \"South Land\") is one of the names given to a hypothetical continent which appeared on European maps between the 15th and 18th centuries. Although the landmass was drawn onto maps, Terra Australis was not based on any ac... |
[
"How are quantum computers programmed?"
] | [
false
] | Edit: Thanks everyone for the responses, but apparently I don't know as much about quantum computing as I thought I did. I am thoroughly confused. | [
"Look into the Quipper language.",
"Here is an academic paper: ",
"http://arxiv.org/abs/1304.5485",
"A simple rundown: ",
"http://www.mathstat.dal.ca/~selinger/quipper/",
"A press article: ",
"http://www.kurzweilai.net/quipper-language-makes-quantum-computers-easier-to-program"
] | [
"Currently, there aren't really programmable quantum computers in the way we think of programmable classical computers.",
"That said, many people have already pointed to the D-wave computer, which, while possibly not a quantum computer in any sense, does demonstrate the sort of way a quantum computer might be pro... | [
"D-Wave is a special case and can only solve problems that can be formulated in a certain way. D-Wave is cool and has done some awesome stuff, but is not necessarily what some people mean when they say \"quantum computer\" more info is available on the wiki."
] |
[
"Does taking antibiotics affect the gut bacteria in any way?"
] | [
false
] | [deleted] | [
"That is correct.",
"Side effects may include any number of stomach problems, including diarrhea and the various Pepto symptoms. ",
"Depending on how broad spectrum the drug is, you may experience worse or longer lasting side effects. "
] | [
"Some people take probiotics while on antibiotics to help stave off intestinal symptoms that result from taking antibiotics. I was told as a home remedy to eat yogurt (like, the real stuff) every day during a course of antibiotics to stave off stomach trouble as well as yeast infections (because that sometimes happ... | [
"Yes. For example, taking antibiotics can kill off the good bacteria which compete with Clostridium difficile, a particular species of bacteria. C diff left unchecked can cause pseudomembranous colitis, leading to things like diarrhoea "
] |
[
"If I struck the G3 key on a piano 130 times a second(frequency of C3) would I audibly hear a fifth chord?"
] | [
false
] | The title is just a singular example of a question that can be posed innumerable ways. I just want to know if pitches can be produced by repeated sounds that have their own pitch, if those pitch producing sounds are made frequently enough(walking at 400 steps a second creating the appropriate pitch). If not, why? | [
"Because of overtones, you audibly hear a fifth cord any time you strike any piano string. The G3 also makes a barely audible \"D6\" and a bunch of other intervals.",
"If you hammered the G3 at a frequency of C4, you'd definitely hear the C4 note, but not in the usual timbre because you'd be generating a weird wa... | [
"I'm going to expand on overtones a bit for the wider audience because I think it's really interesting. When you pluck a string and it vibrates, you get a standing wave pattern on a string. Overtones are produced because there are multiple possible standing wave patterns (modes), each multiples of the fundamental f... | [
"Yes, you would. In physics/math terms you can represent that action as your regular G3 time function (i.e. how the sound develops as a function of time) convoluted with a dirac comb of frequency 130 hz. Taking the Fourier Transform of this to get the frequency domain gives you a dirac comb of frequency spaced 130 ... |
[
"Why are eyes horizontally arranged and not vertically?"
] | [
false
] | One would think that there would be a bunch of creatures that would have eyes in a vertical arrangement. Why isn't there more diversity in eye location? | [
"Most of earth is on a plane",
"Eyes are positioned to maximize the view of that plane. There is no deep survival need to maximize looking up. ",
"Flatfish lay on the sand, that's why both their eyes are on the same side of the body. Because most of their needs lie on one side of their body"
] | [
"That’s not how it works. ",
"It would only happen if people with weak left hands had an advantage over those with strong left hands that increased their survivability."
] | [
"Peripheral vision.",
"Most things we would want to see (predators, prey, natural resources whatever) thend to be on the same plane that we are on, ground level. ",
"It would therefore make a lot of sense to stretch our field of view horizontally, instead of vertically."
] |
[
"Why are some animals only able to mate in certain times of the year?"
] | [
false
] | I was under the impression that, in general, evolution favours the path that creates more offspring. So why aren't all animals like humans, and can mate 24/7/365? | [
"The short answer is that timing the pregnancy and birth of offspring to particular times is extremely important, and beneficial. Unlike humans, most animals in the wild do not have resources available all of the time, especially not the resources necessary to reproduce. For example, if something that eats plants s... | [
"It might also be worth noting that there can be strong seasonal variation in the tropics as well. We sort of like to think that its sunny, hot and lovely all the time near the equator but most places will have distinct wet/dry seasons that clearly effect the availability of fruits, new leaves, seeds for the animal... | [
"Apart from timing having to be synchronized with the peak of resource availability, you can also think about other reasons why mating would be good to occur at specific time points. Many sea organisms have a mating event, in which the males release their sperm at the same specific time as the females also have the... |
[
"Does carbon dating work in space?"
] | [
false
] | I just saw Prometheus last night, and the scientists in the movie carbon-dated things even after leaving Earth. Is this possible in reality? Can we carbon date the moon, for example? | [
"First of all, carbon dating (C-14 that is) only works for ages up to some 50000 years. It degrades to fast to date anything much older.",
"Secondly, Carbon dating works because the C-14 levels in our atmosphere are kept constant by cosmic radiation which generates C14 in the upper atmosphere. Once Carbon is inco... | [
"Yes....and that is why I wrote",
"\"This would also work on other planets provided that the concentration in the atmosphere stays constant.\""
] | [
"Carbon dating compares your sample to a standard. On Earth, all living things have the same percentage of C-12 vs C-14. On another planet, they would have to establish a standard first, using several currently-living organisms from that planet. The method could eventually be used though.",
"However, if the or... |
[
"Can a single Qubit be entangled in more than one cluster state simultaneously?"
] | [
false
] | And further, if an existing quantum computer were to have a qubit added, would it be possible to have it entangled with only some of the original qubits, or would that be nonsensical? | [
"In principle you can entangle whatever you want if you have a suitable setup. Not every entanglement will be useful."
] | [
"Yes, and yes, but I will go a little into the nuance. ",
"Qubits are not inherently entangled, they are used to create entangled states. In principle, a quantum computer can have an array of independent qubits with their own states. Then under a specific operation the states of these qubits can be entangled (cre... | [
"Entangled just means two (or more) qubits (or any quantum-behaving object really) have a special kind of relationship between their measurable values.",
"You can create any kind of qubit relationship you imagine with the right quantum circuit.",
"A better way to think about working with a large number of qubit... |
[
"What does it actually mean if a quantity is an exact differential?"
] | [
false
] | I came across this sentence: "since heat is not an exact differential it is not a property of the system. It is a path function." So how can those things be inferred just by knowing that heat is not an exact differential? | [
"The precise mathematical definition of an exact differential form is a differential form that can be written as an exterior derivative of another differential form.",
"In thermoynamics, the one-form dU (the differential internal energy) is an exterior derivative (d) of a zero-form (a function) U.",
"In other w... | [
"Thank you so much for your response. Now I can finally sleep in peace!!"
] | [
"Very clear explanation. I wish my stat mech teacher explained it as well as you just did. "
] |
[
"Would a swimmer be faster in salt water rather than fresh water?"
] | [
false
] | This question piqued my interest due to shark week and Michael Phelps' race against the shark. Since all of his record settings times have been in fresh water, it would be fun to find out if this scenario being held in salt water would help or hurt his performance. | [
"I would say the additional resistance and the additional thrust would cancel each other out.\nBut the higher buoyant force of sea water could be a downside as swimmers have to dunk their head underwater to lower the resistance.",
"But I'm not completely sure and would also like to hear a definitive answer."
] | [
"The only information I could find was related to boats. ",
"I'm also of the opinion that any friction or drag would be offset by the increased thrust from each kick. Would increased buoyancy be a benefit since you'd be able to put more energy into forward motion? ",
"E: clarity "
] | [
"I really only found one article on this topic, it claims salt water being beneficial due to the increased buoyancy, just as you said.",
"It doesn't seem to be the most scientific article but here you go anyway: ",
"http://woman.thenest.com/fresh-vs-saltwater-swim-triathlon-17705.html"
] |
[
"Why do we need spinors?"
] | [
false
] | I understand that there is some important connection between spin and the groups SU(2) and SO(3). It's often pointed out that SU(2) double covers SO(3), and that the Pauli matrices form a basis for the Lie algebra su(2) (up to a factor of i). But I'm having trouble understanding the connection. As I understand, SU(2) i... | [
"The commutation relations between spin observables are derived in terms of the canonical commutation relations of linear position and momentum.",
"In some sense, this is just one way to derive those relations. But more abstractly, you can say that any Hamiltonian which has some transformations with the structure... | [
"Would you say my understanding so far is correct?",
"Yes, the first paragraph is all correct!",
"Could you give some examples of quantum systems with SO(3) symmetry without spinor representations? Would a particle in a radially symmetric potential count?",
"Yeah, just considering a spin-0 particle in a radia... | [
"Yes, I realise the commutation relations could be derived from the properties of SU(2). My question was why and how this connects to the orbital angular momentum approach."
] |
[
"Is it possible to see odours?"
] | [
false
] | null | [
"However, it is possible to detect the molecules themselves via EM (spectroscopy), is it not?"
] | [
"However, it is possible to detect the molecules themselves via EM (spectroscopy), is it not?"
] | [
"Something applicable to such a large range of possible compounds and requiring such sensitivity (since many odors are present in low concentrations and you probably want to reprieve things which aren't already right under you nose) is practically impossible. Spectroscopy techniques are not sufficiently powerful wi... |
[
"Which direction is the center of universe?"
] | [
false
] | null | [
"Everywhere.",
"There is no center to the universe. The CMB shows the universe at 370,000 years old - and it is uniform. Thus each point is the center of the universe from that points perspective.",
"No center, no edge. However, each point in the universe has an observational sphere beyond which light has no... | [
"This",
" video, posted yesterday, does a pretty good job explaining the same thing, but visually. "
] | [
"The universe is not expanding from, or into anything. The universe was not created ",
" space... it ",
" space.",
"Basically take two distant points, more space is being 'created' between those two points.",
"Here is a good explanation of it",
"."
] |
[
"What prevents animals from learning a human language?"
] | [
false
] | Specifically animals with a similar vocal chord structure to humans. I know parrots just repeat what you say, but have no idea what you are saying, and I also know that, certain apes have learned sign language, but I'm talking about actually speaking. | [
"Off topic but people might find it interesting: lyrebirds use a whole range of mimicked noises but have a few calls of their own. There's a theory kicking about that those calls aren't lyrebird calls, but are mimicked from species that have since gone extinct; even though they're gone, their calls have continued t... | [
"Animals do communicate in a verbal and non-verbal manner. However, I'm guessing your talking about a defined language with semantics, grammatical structure, and generativity. The answer, simply put, is animals lack the brain power. I can't exactly say what came first, large human brains capable of understanding... | [
"Only very few creatures can produce the range of sounds humans can.",
"And by the way, there was a parrot that could understand hundreds of words and even make simple requests by speech."
] |
[
"When considering the Bohrs model of an atom, what happens when you apply more energy to an electron than is needed for the second energy level but not enough for the third?"
] | [
false
] | null | [
"or will the electron simply not accept the excess energy",
"This one."
] | [
"If you don't give it the right energy to jump to some other orbital, the transition simply won't occur."
] | [
"I understand that, what im asking is if the electron is given not the exact amount of energy required to jump to the third energy level but has enough to go the the second.",
"Will the electron simply hold the excess energy and release it all as usual, or will the electron simply not accept the excess energy ect... |
[
"Does alcohol have an inhibiting effect on the immune system?"
] | [
false
] | I have seasonal allergic rhinitis (Hayfever) and am also slightly allergic to dust and animal dender (particles of shed skin and hair). However, when I drink some amount of alcohol the symptoms seem to temporarily fade away. I noticed this when I was at a birthday where there were cats running around and I forgot to ta... | [
"Chronic alcohol users are more susceptible to certain bacterial infections, mainly lung infections caused by gram-negative organisms (pneumonias, and TB). This is primarily due to changes in which immune cells act when they encounter a pathogen or site of infection in the lung tissue. Chronic EtOH affects cells ... | [
"Alcohol has a vasodilatory effect",
" at lower doses. Swollen parts of the body (like a blocked nose due to swelling) could be relieved temporarily.",
"(Funny thing is that especially the mucous membrane of the nose can be relieved by vasodilatory medicaments too. Some antihistamin-combinations contain pseudoe... | [
"Yes, both acute and chronic exposure to alcohol has been tied to immunosuppression and susceptibility to infections. I don't know if its effects have specifically been looked at in allergy models, but allergies are mediated by Th2 responses, which are also involved in protection against extracellular invading pat... |
[
"Dr. Robin Carhart-Harris from Imperial College London Is our Guest on LondonReal today Any QUESTIONS FOR HIM?? Holla"
] | [
false
] | null | [
"Have they found a specific dose to be most effective? Single treatment vs. multiple treatments? Temporary like a couple months or longer lasting effects like years in the removal of depression?"
] | [
"I am curious, did the research from the documentary \"The Spirit Molecule\" about DMT influence you to conduct this research? Secondly do you believe you can sequester the negative image that is held by the public on such drugs like psilocybin? Thank you."
] | [
"Please provide the links to studies or reports of psychedelics causing (death, stroke, seizures, etc) as you mention"
] |
[
"Why do mammalian infants/young exhibit playful tendencies but eventually transition into a state of lesser playful tendencies and frequency (I.e. toddlers, kittens, elephants)? What causes that degradation of playfulness as a mammal matures?"
] | [
false
] | Does it involve developing a more full understanding of the mechanics of the world around them (and us to the extent that our culture and media and technology influence us in ways that most mammals are not influenced by)? Does impulsive action upon or reaction to curiosity decrease as a mammal matures? | [
"There is a current theory that play between young animals is meant to teach lessons integral to survival and the spread of genes. For example, lion cubs that wrestle will be more prepared when the time comes to fight for mates or defend the pride.",
"I don't know much about why playfulness decreases with age, so... | [
"Do you have access to an academic library? And time to read? If so, browse through some stuff like this ",
"http://scholar.google.com/scholar?hl=en&q=animal+play+age+behavior&btnG=&as_sdt=1%2C39&as_sdtp=",
" "
] | [
"Just some background, I work with Marine Mammals.",
"As for Seals and Sea Lions, their playful activity both physically, and vocally is thought to be a form of exercise as well as what AbedtheArab said. Playful growls during play turn into aggressive vocalization, and localization calls. Physical activity helps ... |
[
"Why do we age?"
] | [
false
] | I get that it’s because our cells don’t replicate as much as they do when we are younger, but why do they act like this? They are all replaced within a short amount of time so they are not the one aging. | [
"When the cell is being reproduced the DNA chromosomes have end caps. These caps get smaller with every reproduction until they can't be reproduced anymore.\nSecond: mutation. We are constantly under a mutagen environment so our cells have to fix these errors but they mistake sth from time to time"
] | [
"Another way of looking at it, is that our bodies are good enough to get the job done. They generally last long enough to produce offspring. There’s no selection pressure to create a potentially more complex or resource demanding body that live longer or indefinitely. ",
"Likewise, a hereditary mutation that cau... | [
"Alright thank you very much. "
] |
[
"Are there equations that model how rivers change their course over time?"
] | [
false
] | I was looking at and it reminded me of the How accurate this idea? The KH-instability is only intended for use at the interface between two fluids, and the riverbed is solid. Are there good equations modeling how rivers change their course over time? | [
"How accurate this idea? The KH-instability is only intended for use at the interface between two fluids, and the riverbed is solid.",
"There are some obvious apparent similarities in form (i.e. both produce vaguely sinuous shapes), but in terms of process, as you've guessed, it doesn't really work as the sedimen... | [
"ok so I did some googling and found this ",
"article",
" which seems like what you are looking for. I started looking at it but then realised it is 93 pages long... I'll try my best to answer the gist of your question. ",
"Firstly, the Navier Stokes equation set is used to describe the fluid flow. Completel... | [
"Unlikely since the model would have to be based on the assumption that all the ground soil is uniform. No river exists in that kind of environment.\nBut generally, all bends in the river grow out from the center of the radius because of the centripetal force being greater on outside of the bend."
] |
[
"Why can't helium freeze at 0K?"
] | [
false
] | Just Why can't it? In theory this should be logical but in reality it remains a liquid. Why? | [
"The state of matter an atom or molecule is in depends on both the temperature and the pressure. This is graphed in what is called a phase diagram. ",
"This is the phase diagram for Helium",
".",
"As you can see there is a point when it is solid which is at about 20 atm at 0K. So it is possible possible but j... | [
"Are there any gaseous substances at 0K for any pressure?"
] | [
"The lowest theoretical ground state for any quantum particle is not zero energy, it is called the zero point energy. The fluctuations and uncertainty in the wave function mean that it's average energy needs to be above the minimum in order to be able to fluctuate. This is why things at absolute zero can still have... |
[
"Do we feel temperature, or transfer of heat, when we feel that something is hot or cold?"
] | [
false
] | I saw a post on : [Why do certain surfaces feel colder or warmer to the touch when they are seemingly the same temperature?] And of course it has to do with the rate of conduction of the heat. But that also implies that what our nerves are actually sensing is not the actual temperature, but the rate of heat transfer. I... | [
"The thermoreceptors in the body are designed to detect the transfer of heat, not the temperature of an object.",
"this is why, in a room with a piece of wood and a piece of metal, even though all of the objects in the room are at temperature equilibrium, the metal feels colder due to the fact that metal is a bet... | [
"Are we really sure you aren't simply measuring the interfacial temperature at the skin? A higher conductive surface would thus feel colder because the steady state temperature of your skin in contact with it would be lower. Similar to how you feel colder when the wind is blowing. The blowing wind increases the hea... | [
"Yes, the first part was what I was looking for! :) The second part was pretty much what was figured out in the other thread (as well as by me).",
"I would like to know more about how the thermoreceptors work in depth though, if anyone is up for it :)"
] |
[
"How do photons transfer angular momentum to macroscopic objects?"
] | [
false
] | As I understand it, angular momentum of a photon is related to its spin, which does not actually have anything to do with the conventional definition of spin, but is just a quantum property. How then, if the photons are not actually rotating, do they transfer angular momentum to make a macroscopic object actually rota... | [
"Spin ",
" angular momentum, it just doesn't come from something rotating. Just as energy can shift among kinetic energy and potential energy and mass, angular momentum can shift between spin and rotational angular momentum."
] | [
"Nothing I know of offhand. Lots of books cover this -- any text titled something like \"Modern Physics\" or any basic quantum book will explain the basic facts.",
"It's worth noting that to see ",
" this arises (as opposed to just asserting some results and saying it ) you need to combine special relativity a... | [
"I've taken intro classes on those, so if you think you have a college sophomore level explanation, I would love to hear it."
] |
[
"When Elon Musk said he will decrease the cost of trips to Mars by \"4.5 orders of magnitude\", how much exactly is that or what's the percentage?"
] | [
false
] | null | [
"30,000 times."
] | [
"Would you mind showing how you got there? I know 4 orders of magnitude is 10,000 x , but 30,000?!"
] | [
"The .5 is the square root of 10 which is roughly a factor of 3."
] |
[
"Why is water turn from clear to white when it freezes?"
] | [
false
] | [deleted] | [
"It dosen't always, but unless you take precautions there are dissolved gases in the water, as it freezes these gases are pushed out and form small air bubbles, which are then frozen in the ice. These air bubbles are responsible for the white color by scattering light as it goes through the ice."
] | [
"Firstly, ice isn't necessarily white. Secondly, water isn't colourless but actually ",
"slightly blue",
". The reason that ice is often opaque, especially in the case of snow, is because of irregular surfaces of ice crystals scatter light coming towards it out in lots of directions, rather than letting the lig... | [
"Here's how to avoid it"
] |
[
"For molecules that have a benzene ring, does it make any difference which way the ring is oriented?"
] | [
false
] | So for example if I rotated the ring in by 60 degrees would it have any meaningful effect on the molecule? Do chemicals like this appear both ways? | [
"No, it would not have any effect. The double bonds in the benzene ring are delocalized pi bonds, and form something like a ring if you look at an ",
"electron density diagram",
". It acts in a similar way in the epinephrine molecule, just warped by the presence of other things besides the CH units."
] | [
"The alternating double bonds in benzene are only a convenient way of showing the bond order. You'll often see representations ",
"like this",
" that shows the double bond change locations. In reality, rather than rapidly switching between all resonance structures, all bonds are of order 1.5, rather than 1 or 2... | [
"As far as drawing a chemical structure it makes no difference. They are they same molecule.",
"In terms of the energy of various conformers of the molecule by rotating around single bonds, it would make a difference in the energy of those two conformers, but generally drawing a chemical structure does not imply ... |
[
"Is there steps i can take to get over my reaction to gore?"
] | [
false
] | null | [
"If you don't get answers here you might try ",
"/r/medicalschool",
" or ",
"/r/medicine",
"."
] | [
"Thank you!....I kinda had a feeling this was not the proper thread."
] | [
"Np. I didn't have time to answer before, but for what it's worth I'm kind of like you, very squeamish. When I was about 12 my big sister broke a plate while washing dishes, and the sharp ceramic edge fell right on her radius near the wrist. It made a very deep cut, the first time I had ever seen white stuff in a c... |
[
"Could frozen fish be lying around on the surface of Europa?"
] | [
false
] | Well, I mean frozen life. If the water plumes on Europa suck up life from the water underneath and blow it out over the surface, would the life get destroyed and be unidentifiable or could a probe tell us that this was once a living thing? Would bones or scales or horn or even soft tissue, like singe-cell creatures sur... | [
"A few kilometers of ice is going to stop pretty much all incoming radiation."
] | [
"The plumes recently reported on Europa by NASA offer a golden opportunity for investigations based on this notion. ",
"Plume around Enceladus were identified and examined by Cassini about 3 years ago, and the presence of salt was confirmed. Even more interesting: hydrothermal silica was identified, a litteral \"... | [
"Interesting question. I was also wondering about radiation below the surface of the ice and whether life could exist there. ",
"According to wikipedia: The radiation level at the surface of Europa is equivalent to a dose of about 5400 mSv (540 rem) per day,[40] an amount of radiation that would cause severe illn... |
[
"Paper vs Styrofoam Cups?"
] | [
false
] | For my morning coffee, what's better for me, my children's children and the plant as a whole? Yes I know a reusable mug is the best, but in just paper vs Styrofoam. | [
"Paper cups (unless marked biodegradable - most are not) have a wax coating which makes them non-recyclable and take 20+ years to degrade in a landfill. Styrofoam doesn't biodegrade, it just breaks down into smaller and smaller particles.",
"Paper cups do take more energy to produce and to transport (higher weigh... | [
"Paper cups (unless marked biodegradable - most are not) have a wax coating which makes them non-recyclable and take 20+ years to degrade in a landfill. Styrofoam doesn't biodegrade, it just breaks down into smaller and smaller particles.",
"Paper cups do take more energy to produce and to transport (higher weigh... | [
"In the short term, sure. But over the long term, production will be driven by demand for the product. Manufacturers aren't going to just indefinitely crank out millions of cups that they can't sell."
] |
[
"If all of the planets in the solar system came from the contents of the same star (supernova), then why are they all so different?"
] | [
false
] | For example, Earth is the only planet with water (with the exception of a moon or two). Why is it that only one planet got the right combination of elements for life? | [
"Your initial assumption is wrong - the solar system, including the Sun, wasn't formed from a supernova, but from gases and dust the started to coalesce, perhaps because a nearby supernova exploded, and the shock waves pushed the stuff together. Gravity took over, and small lumps of stuff became bigger and bigger.... | [
"From the rules at the sidebar:",
"Please keep discussion:",
"Free of layman speculation"
] | [
"A lot of it comes down to each planet's distance from the sun and the size of the planet itself. I'll use Mars as an example. Mars is further away from the sun, so it generally is much colder than the earth. Mars is smaller than the earth, so it has less gravity. Lower gravity makes it harder for the planet to hol... |
[
"Does ethylene break down? I know it ripens fruit, but does ethylene itself get broken down by microbes or fungi?"
] | [
false
] | null | [
"Keep in mind that there are also anthropogenic emmisions of ethylene. From what I could find, it breaks down quite fast reacting with OH radicals and ozone (lasting only a couple days in the atmosphere). ",
"As for biological breakdown:",
"In an atmosphere containing high concentrations of\nethylene, the soil ... | [
"Awesome! That really did answer quite a bit. So organisms break it down in the soil pretty readily. But also create it? I hope the breakdown by soil organisms is high!",
"I accidentally put banana in one of my 15 gallon no-till pots and was wondering how long any effects would last. It's a really active rhizosph... | [
"You're welcome! I wouldn't worry about the ethylene, it's probably already gone. And yes, many microorgs produce it, not necessarily related to its role as a hormone (being such a simple hydrocarbon it can be involved in synthetic pathways)"
] |
[
"Does anti-matter have to react /annihilate with its exact counterpart? Like anti-hydrogen with hydrogen, not anti-hydrogen with helium, for example."
] | [
false
] | I’m conscious making, containing and mixing this stuff is darn complicated but theoretically, would anti-hydrogen ‘annihilate’ with other nuclei? | [
"Nope.",
"https://en.wikipedia.org/wiki/KEK",
"They did some experiments, and found that in liquid helium antiprotons could survive a while, a few miliseconds.",
"This did some experiments on it. The anti proton will tend to displace an electron from the atom (since it's positive), and then annihilate with a ... | [
"Stability has nothing to do with annihilation reactions. Lots of antiparticles are stable, but will still annihilate with their corresponding particles."
] | [
"They don't necessarily have to annihilate, they can scatter off of each other, or even form bound states (which will subsequently annihilate if they are a corresponding particle and antiparticle). ",
"However in any cases where anti-elements are being produced by humans (in accelerators, for example), it's surro... |
[
"How are sodas and other carbonated beverages not as effective at rehydration as say gatorade?"
] | [
false
] | I am a High School (American)Football player and was always told not to drink sodas but gatorade instead. Their anti-soda reasoning: sugar, but when I look at the labels on gator/powerades they both have lots of sugar and sugars are carbs which are needed for energy. The main ingredient in both is water. So before I st... | [
"Actually, that's a HORRIBLY written article. Its intent is to demonstrate the soft science marketing of sports drinks is not fully backed by science. And they are right. However, that doesn't mean there are not good reasons for using sports drinks under conditions in which exercise is dehydrating. ",
"There's a ... | [
"The British Medical Journal just came out with a study that says sports drinks are basically no better than water.",
"http://www.bmj.com/content/345/bmj.e4737?view=long&pmid=22810386"
] | [
"5k is too short. Run for two hours on a hot day instead. "
] |
[
"Is lead only dangerous through physical contact and/or ingestion? Can you also get lead poisoning through proximity?"
] | [
false
] | How would I check a vacuum insulated bottle for lead? Is it just the solder point on the bottom? Or the powder coated paint as well? Would I need to check the inside of the bottle too? What's the best home kit? | [
"In order for any chemical to harm you it has to get into your body.",
"\nLead can poison humans in several ways:",
"\nIngestion (Meaning you can eat it) is most common with young children (6 months to 6 years) who frequently put their hands onto surfaces containing lead dust or into lead contaminated soil and ... | [
"I wouldn't be concerned if it was me, BUT if you are worried then it should be fairly easy to get over to a government agency with an XRF. They are radioactive so the state keeps a list of every one that has been registered in the state (for example there may be an indigenous tribe that owns one near you.) ",
... | [
"Yeah I would think it's nbd but better safe than sorry. Also seems like your place is the exception, everywhere else around me charges $. I'll just spend the $20 on a bottle made in the US lol. Thank you! "
] |
[
"Biologists, what in the hell are these white balls on my tree? They're too fluffy and cute to not be evil..."
] | [
false
] | Imgur album They're each about an inch across and are growing about halfway out on the branches of this tree. Is it some sort of caterpillar sac or some type of fungus? Google was unfortunately unhelpful this time. Should I kill it? What's the best way to kill it? | [
"Wooly Oak Gall"
] | [
"Thanks! These are definitely them, especially that first picture on the Oak Gall category."
] | [
"You will need an android or I-phone as I remember."
] |
[
"Acceleration/Speed in Space"
] | [
false
] | One thing that has always bugged me, is that when you watch sci-fi movies, the "engine" of the ships are always on. It was my understanding that, since there is no friction in space, once you propelled yourself to your desired velocity, no additional acceleration would be required? Is this just to give the effect of th... | [
"your description, while not completely wrong, ignores a painful amount of orbital dynamics."
] | [
"While you are correct in your knowledge that there is no friction in space due to atmospheric drag, there is still a great deal of gravity that your ship will constantly have to escape (by accelerating, using its engines). While this is not as much of a problem in interstellar space because of the great distances ... | [
"This is sort of true. It's absolutely correct that there's no such thing as relativistic mass, or \"apparent mass,\" as you termed it. It's ",
" strictly true that mass has nothing to do with it. Mass is what keeps ",
" from being able to move through space ",
" the speed of light. It isn't that your mass \"... |
[
"Does/Can there exist a radio laser?"
] | [
false
] | Is a list of wavelengths and companies which produce lasers as products. Is an image of colloquial terms we use to define different ranges of light by wavelength. Light being a spectrum of electromagnetic waves, and "radio" waves being among them, begs me to ask: Does/Can a laser exist which emits a beam of light with ... | [
"Yes! in fact radio wave laser were invented and produced before the other types of laser you commonly see today. A laser is just a coherent beam of photons, which could, in principle, be any wavelength. ",
"You can learn more in the wiki article on MASERs",
" (M for microwave instead of L for light)."
] | [
"Even better: ",
"they're naturally occurring."
] | [
"That is really cool stuff! I had no idea - thanks for sharing"
] |
[
"Is it true that not sleeping can actually kill you?"
] | [
false
] | [deleted] | [
"Lack of sleep wouldn't be the direct cause of death. It would be from something else. Chances of diabetes goes up, memory loss, headaches, deficiencies in your immune system, weight gain or loss, and so on. So, insomnia would be an indirect cause, like being in a car is an indirect cause for people that die in car... | [
"However, FFI is an inherited disease, and while it can appear in people without the gene:",
"Only eight cases of sFI have ever been diagnosed as of July 2005.",
"Wikipedia on FFI"
] | [
"This isn't correct, there is a condition known as FFI.\n",
"http://en.wikipedia.org/wiki/Fatal_familial_insomnia"
] |
[
"Are domestic cats biologically adapted to survive North American winters on their own?"
] | [
false
] | I've always wondered about the ads that say "If your cold, they're cold. Bring them inside." Does a domestic cat really need human intervention to survive winter? | [
"It depends on the breed. Short hairs, of course, don't have much insulation. Most long hairs have been bred just for long hair, not insulative hair (there's a difference), so they're all that much better off. Only a few breeds, such as the Maine Coon, are naturally adapted for the cold."
] | [
"If that's the case how do strays still exist come spring? Or are you assuming that the cats will just sit there in the snow and not attempt to find shelter and warmth? I would say those are definitely adaptations that allow cats to survive northern winters."
] | [
"If you look at the prevalence of stray and feral animals - particularly cats - in both North America and in Europe (I have no data for East Asia) there is a decrease in the number of strays/ferals as one moves south to north. While there are cultural factors associated with this, as well as economics, the more se... |
[
"Conservation of momentum/energy question"
] | [
false
] | You are in deep space next to/standing on a relatively massive object, but not so massive that the gravitational force between you and the object becomes significant. Let's say it is about 10,000kg. You push off with your legs as hard as you can, and begin to move away from the mass. Momentum is conserved, but suddenly... | [
"The kinetic energy comes from your legs."
] | [
"This guy is right! The hamburger you ate for lunch is stored in your body as chemical energy and then used later to do things like push 10,000 kg rocks with your legs."
] | [
"Yup. You eat food and your body uses what is essentially electrostatic energy in the chemical bonds between atoms/molecules in the food to make your limbs move around etc. The process that takes chemical bond energy to human body mechanical energy (",
"metabolism",
") is really fascinating."
] |
[
"Schrodinger's cat - from the cats perspective?"
] | [
false
] | So I was wondering how schrodinger's cat felt about it's own famous thought experiment. Sure, the cat is both alive and dead to the outside observer. But inside the box, the cat itself is definitely alive or dead. At some point the observation is made and... what happens? Those 2 reference frames need to reconcile them... | [
"Schrodinger's Cat isn't an illustration of how quantum mechanics works, it's a thought experiments devised by Schrodinger to demonstrate the absurdity of the ",
"Copenhagen Interpretation",
" of quantum mechanics. By design, it's not supposed to be reconcilable or make sense. ",
"The Copenhagen interpretatio... | [
"This reply presumes that we are considering Schrodinger's thought experiment from a historical perspective, rather than what we would say today about such a thought experiment. Today, we should say that the answer is interpretation dependent. Indeed, Schrodinger's was an argument from incredulity, but these days p... | [
"Well, again, this is interpretation dependent, but it sounds like you are interested in the Everettian (\"many worlds\" stance. In that case, we would say that there is an alive cat in superposition with a dead cat, and when a measurement is made, the state of the cat becomes entangled with the observer, meaning t... |
[
"Where do my eyes focus when looking at a mirror?"
] | [
false
] | For example, if I'm standing 5 feet away from a mirror, are my eyes focused on the mirror 5 feet away? Or the projection of me, 10 feet away? I was looking in a mirror earlier and started to wonder. | [
"If you are standing 5 feet away from a mirror and your eyes are focused on yourself in the mirror then your eyes are focused as if you were looking at an object 10 feet away. The picture on a mirror is a reflection, not a projection."
] | [
"You can easily test this by standing in front of the mirror and pointing at it so your fingertip is touching the glass. You can't focus on both your fingertip's reflection, and your face's at the same time."
] | [
"You also can't replace your glasses with walking backwards while holding a mirror (that would be pretty cool, though)"
] |
[
"If the universe is expanding at a non-constant rate (accelerating), what force is causing it to expand?"
] | [
false
] | [deleted] | [
"Dark energy is the term that has been given to what is causing the accelerating rate of expansion. We've named it, but at this point we don't really know what it is."
] | [
"here be dragons",
"'We don't know' sounds more appropriate to me. "
] | [
"No, more like \"Here be a vacuum energy density that has been measured to be 10",
" grams x c",
" /cm",
" , according to several independent observations.\""
] |
[
"How much mass separates Jupiter from becoming a star ?"
] | [
false
] | As i understand it a star is a great enough amount of matter (Hydrogen) that its immense gravitational force squeezes its hydrogen atoms together fusing them into helium, the resulting extra energy produces heat and light. So my question is how much bigger would Jupiter have to be before its gravity would cause its hyd... | [
"Gas giants edge into ",
"brown dwarfs",
" at around 13 Jupiter masses and full fledged stars at about 75 to 80 Jupiter masses."
] | [
"Could it be possible to have a gas giant with a density close enough to fusion around a much larger star in a highly elliptical orbit such that the gas giant could produce enough compressive force at perigee for fusion but not at apogee? Or would such a gas giant ignite and stay ignited until it dispersed/burnt ou... | [
"If 13 Jupiters were gently collided, would they start starring?"
] |
[
"Can anybody provide a complete explanation of how permanent magnets work (to an electrical engineering student)?"
] | [
false
] | [deleted] | [
"Thanks to ",
"Insane Clown Posse",
", this is an faq. ",
"Here you go"
] | [
"It's worth pointing out that the words \"magnetically charged\" are being used in a different sense from \"electrical charge\".",
"\"Electrically charged\" means for an object to have gained a net electrical charge.\nWhile Electrical charge itself is never created nor destroyed. ",
"\"Magnetically charged\", ... | [
"It's worth pointing out that the words \"magnetically charged\" are being used in a different sense from \"electrical charge\".",
"\"Electrically charged\" means for an object to have gained a net electrical charge.\nWhile Electrical charge itself is never created nor destroyed. ",
"\"Magnetically charged\", ... |
[
"If a water balloon was popped in space, would it retain its shape?"
] | [
false
] | [deleted] | [
"It would not boil just in zero gravity.",
"It would boil in outer space due to lack of pressure. In 0atm water can only be either ice or vapor."
] | [
"No for two reasons. First, the action of the rubber membrane contracting back as it ruptures would disturb the fluid inside. Second, water does not stay liquid in space, it boils and becomes a gas very quickly."
] | [
"Really? Why does it boil quickly? Do other liquids have this same property in micro-gravity?"
] |
[
"Do tree rings always correspond to a year?"
] | [
false
] | I don't know why - but that just doesn't seem right to me. I've been taught that each ring corresponds to a year, but is it true? Are there variations? What's so special about a year? How would seasons affect it? | [
"Forest ecology PhD student here. Only tree species found in temperate regions with extreme annual fluctuations in climate have rings that reliably correspond to a year. This is because trees grow rapidly in warm weather and very little in cold. Tropical species largely do not have rings at all due to the relativel... | [
"No. They correspond to periods of rapid and slow growth, which is usually caused by the yearly changes in light and rain availability.",
"For this reason, trees which live in deserts or areas with rapidly changing availability of resources often do not give accurate tree ring counts (over or under-producing them... | [
"There are no good methods other than ring-counting to my knowledge. However, it isn't usually a huge problem because plant populations are size-structured, as opposed to animals, which are age-structured. This means that certain traits and functions of a plant are determined more by its size than its age. For exam... |
[
"How does all of the \"normal\" gear get into a clean room?"
] | [
false
] | So I've been watching a video about the James Wood Space Telescope and where all the humans are in bunny suits, you will see "normal" stuff like ladders, office chairs, desks and even high lifts inside the clean room. My question is, how does all that stuff get so clean that it can be inside the clean room? Office ch... | [
"Not sure the exact procedure for entering the clean room, but I do know that there are restrictions on the types of materials that will be allowed based on the amount of dust and offgassing they do. But also, one aspect of cleanrooms is that the ventilation system is designed to introduce filtered air at one end ... | [
"To add to the other excellent answers about the airflow being directed downward, I doubt a cloth office chair is being used in anything better than, say, a class 10000 environment. Cleaner regions generally require furniture with hard, smooth, nonporous surfaces that are wiped down with a solvent upon entry to the... | [
"We make sure they’re clean and compatible (won’t produce particulates) before loading them in. We may let them sit in the gowning up area or some other intermediary room for some time before loading them in as well"
] |
[
"is neuroplasticity region specific or can it be \"transfered\" to other parts of the brain?"
] | [
false
] | In this episode Andrew Huberman talks about how plasticity generated by learning new motor patterns can help the subsequent learning of new material unrelated to the motor pattern. He mentions that this is due to plasticity being a state that the brain is in and not just an event. I find this fascinating but I'm having... | [
"it appears he is using plasticity in a way that does not necessarily match with how it is used in the neuroscientific field which is probably the source of your confusion. when used in the field it generally refers to the ability of neurons to modify their connectivity to other neurons, either via the formation or... | [
"This. Plasticity refers to changing connections, via dendritic spines, and strengthening or weakening existing synapses with other cells. It's happening all the time and the current research shows that the spine \"overturn\" is quite high, meaning the neurons are constantly changing their connections to other neur... | [
"If you want a scientific approach to improving your learning, practice is kinda all i have for you as a non-insider to the field. Its totally possible that broadening your horizons will have a positive impact on your abilities but its also totally possible you hit a physical limit to how far your ability can go (a... |
[
"Can insects get KO'd?"
] | [
false
] | null | [
"They don't have a nervous system like we, animals, do.",
"Insects are animals too, and they ",
"certainly have a nervous system",
".",
"And yes, insects can get temporarily knocked out. For example, there are various compounds that work more or less like chloroform does on humans. I used to work in a fruit... | [
"Defining KO as losing consciousness the first question should be if they have consciousness. They don't have a nervous system like we, animals, do. If you manage to temporarily disable an insect I would prefer calling it being paralyzed. Although I'm not completely sure about this. "
] | [
"I remember using this fly nap stuff too. We used it to sex the flies. Do you know by what mechanism it works?"
] |
[
"How could something like this happen? (x-post r/mildlyinteresting)"
] | [
false
] | I saw on and I think its pretty incredible--the OP said he/she had a lemon tree and an orange tree next to each other. How could this have happened? | [
"This is just an orange with some mild discoloration of its skin. It is not a half orange/half lemon."
] | [
"You're describing ",
"grafting",
", but that clearly isn't the cause here (at least not the whole cause). The graft retains the genetic information of its origin, it doesn't merge the genomes of the two plants.",
"I'm kinda shady on plant genetics/development (cuz ",
"), but I do remember that the fruit wh... | [
"http://www.reddit.com/r/mildlyinteresting/comments/18l6q3/i_have_a_lemon_tree_i_have_an_orange_tree_i_just/",
" this is the original post!"
] |
[
"Naked mole rats are highly social animals, and since they are not endothermic, their colonies sleep communally together. Since this is a recipe for plagues, what pathogens are known to afflict them?"
] | [
false
] | [deleted] | [
"There is one study where coronavirus (",
"Ross-Gillespie et al., 2007",
") caused the death of an entire naked mole rat colony - the consequences of their lifestyles means that inbreeding depression is especially severe, and they are more likely to be impacted by fatal infectious diseases."
] | [
"While I cannot tell you of naked mole rat diseases I think it's important to remember there are more ",
"ingredients to plague",
" including:",
"So just because they live in large colonies does not necessitate infection.",
"Edit: formatting"
] | [
"I heard at the zoo that they have some chambers designated as toilets? Others as larders? Is this true?"
] |
[
"Are there any recorded cases of siblings that are genetically close to being identical twins but aren't?"
] | [
false
] | Let's say siblings who share more than 95% of their DNA with each other. If there aren't any recorded cases of this, how likely is this to happen? I've tried researching both of these myself, but either I'm just plain dumb, or the answer is hard to find. The question was sparked in a discussion with my brother, and som... | [
"It's really not possible. ",
"If you were to completely ignore ",
"crossing over",
", and just pretend that the chromosomes sorted into offspring as single units, your odds of having the same exact set of chromosomes wind up in two different offspring of the same parents would be 1 in 2",
" or about 1 in 7... | [
"Ah shit. You're right. Duh! I've never had a feel for probability, which is really a problem, going into population genetics and all..."
] | [
"Ah shit. You're right. Duh! I've never had a feel for probability, which is really a problem, going into population genetics and all..."
] |
[
"Could a skilled chemist, with all necessary equipment, analyze coke and figure out the formula?"
] | [
false
] | Many products like coke and WD40 are said to have a secret formula, but couldn't someone reverse engineer it? It seems our understanding of elements, molecular physics, and chemistry would let us "see" what is in something. | [
"We could pretty easily figure out all the components of Coke. There are plenty of chromatographic and spectrographic technologies that we use every day that can pick apart each compound and salt in there and tell you exactly how much of what it contains.",
"However, what that does not tell us is exactly how the... | [
"Yes, but that doesn't mean building it molecule by molecule makes sense. For example, they might add a specific spice which contains tens or hundreds of different molecules, then heat it up to hydrolyze some of them to get a specific composition. You could go and take very small amounts of all the hundreds of mo... | [
"Possible. In the patent landscape, reverse engineering (or stealing the formula) doesn't make any difference commercially. Years ago i worked for a major petrochemical company on a patent litigation project, proving that other companies were manufacturing their patented copolymer. This was done using a variety of ... |
[
"Will a force acting on a photon non-orthogonally to its direction of momentum change its wavelength/frequency?"
] | [
false
] | My logic behind thinking this might be so: Force is a time-rate of change in momentum A photon's momentum, since it doesn't have mass, is equal to hbar * c / lambda. The reason I mention the non-orthogonal condition is that if it is so, its momentum simply changes direction and it's well known what happens in that scen... | [
"You're right, the wavelength of the photon would change (this is the basis of ",
"gravitational redshift",
"). You can also understand this as an effect caused by the warping of spacetime (gravitational time dilation changes the frequency of the photon as it travels through a gravitational well).",
"As the p... | [
"Thank you for the concise yes/no answer followed by a more detailed explanation and alternate explanation; this reply is exactly what I was looking for!"
] | [
"Put 1 kg of monochromatic light in a mirror lined massless box.\nApply a 1 N force to the box.\nBox accelerates: a = F/m = 1N/1kg.\nThe energy of the box increases.\nThe Compton frequency of the box increases: f = E / h. \nInside the moving box at some moment there are some blueshifted photons and some redshifte... |
[
"What, chemically distinguishes rocks from other solid chemicals (I.E. metal)?"
] | [
false
] | null | [
"Atoms of metal are bonded together using metallic bonds. This is a type of bond where the electrons of each atom are free to move throughout the bond. Where as rocks and other solid material are mostly bonded together by ionic bonds, where electrons from one atom is completely taken by another atom. Or covalent bo... | [
"Salt is a naturally occurring mineral, so it would fall into the category of a \"rock\".",
"That's not how it works. Rocks are composed of minerals, but minerals are not a subset of rocks. NaCl salt in crystalline form is a mineral, but not a rock. "
] | [
"My question came up because salt is considered a rock. Why is pure salt considered a rock?"
] |
[
"How large are Electronic Health Records (EHR) files?"
] | [
false
] | I understand that one of the major limitations to implementing standardized EHR use nationwide is the size of EHR files and the bandwidth necessary to transmit them. I am looking for information on the average file size of an EHR file, or an estimate of the size of a typical EHR. Full Disclosure: I'm asking the questi... | [
"I have no answer to your question, but is there a universal file type for EHR? I would assume the file size would depend on which EMR you're using?"
] | [
"It makes sense that EHR size would vary based on EMR. Should I then pick a specific EMR and try to determine average EHR size for it? Would you happen to have an insight on which EMR's are most prevalent or most data-efficient? "
] | [
"I can tell you that most hospital systems I've worked in have used ",
"Epic",
", however those have all been major academic medical centers with the means to pay for top of the line software. I don't know what the most prevalent EMR is, and have no idea about how the data is stored at all. The problem you'll... |
[
"Velocity of a nucleus after emitting a gamma ray photon?"
] | [
false
] | If a nucleus were to emit a photon in order to stabilize, would it move in the opposite direction of the photon at the speed of light in order to conserve momentum? | [
"would it move in the opposite direction",
"Yes.",
"at the speed of light",
"No.",
"Nuclear recoils from gamma decays are very weak compared to the typical kinetic energies we're concerned with in nuclear physics.",
"It's always a good approximation to treat the recoiling nucleus as non-relativistic."
] | [
"If the decaying nucleus starts from rest, then conservation of momentum says",
" = -",
", where \"p\" denotes the photon and \"n\" denotes the nucleus.",
"The kinetic energy of the nucleus after it recoils is ",
"/2M = ",
"/2M.",
"The relationship between energy and momentum for a photon is E",
" = |... | [
"This corresponds to ~30 km/s (E/(cM))."
] |
[
"Is uniformity an axiom? If not when does it appear?"
] | [
false
] | Every chemistry class and all other sources on the subject assume that atoms are exactly identical to other atoms(Ex. every 16amu oxygen is uniform) . Is this true or simply an axiom we chose in order to be able to work on that scale? If not, then at what scale does this begin on? | [
"Is this true ",
"This is true. In statistical thermodynamics, two particles that are distinguishable have a different number of permutations of possible states than two indistinguishable ones. (e.g. if you have two holes in a pegboard, you can place a blue and a red peg in them in two different ways, but with tw... | [
"Chemistry (and most of physics) is an experimental science. Atomic masses have been measured to a high degree of accuracy using techniques such as mass spectrometry. We've also been able to probe the inside of atoms for quite some time. We know their composition; every ",
" O is made up of 8 protons, 8 neutrons ... | [
"Every atom IS the same, in the sense that their constituent particles (the quarks and electrons) are all identical to one another. The only thing that can change from one atom to another is the energy levels, and in most environments the atoms are overwhelmingly likely to be found in their ground state; hence they... |
[
"Why can't some people eat certain foods"
] | [
false
] | I personally have an issue with eating cucumbers. I can't eat them without gagging and if I manage to down it, I basically want to throw up. I am hyper sensitive to the smell of them, I can smell them from the other side of a large office if someone has them in a salad, and if they have touched something I can taste/sm... | [
"Anecdotally, I had a bad reaction to a drug as a kid, and threw up immediately after eating one of my favorite foods: an egg McMuffin.",
"To this day, I can't stand the smell of egg McMuffins, and any egg, muffin, and sausage combo is likely to make me react the way you do to cucumbers. ",
"Eggs and sausage, t... | [
"This is called ",
"Taste Aversion",
"."
] | [
"I'm not convinced it DOES have to do with psychological factors, in my case. Almost anyone you meet has a few specific things they just \"do not like\".",
"Taste is 50% or more smell, believe it or not. And you have several HUNDREDS of different types of smell receptors. It could easily be genetic. But way t... |
[
"How far out must an object the size of the Shuttle orbit Earth to escape modern detection techniques?"
] | [
false
] | [deleted] | [
"It depends on what the object is doing, is it emitting or reflecting EMR, if so, how much? Is it exerting a substantial gravitational field?"
] | [
"Let's assume it shares the same characteristics as the Shuttle. Mass, luminosity, etc."
] | [
"Our best infrared detectors are capable of detecting 10",
" watts/M",
" infrared light from a target. Assuming that The infrared light reflecting off a target is 1kw/M",
" and the area is ~100 M",
" (a guess of shuttle S.A.) and that the light is reflected off in a half sphere shape radiating outward poin... |
[
"Does the MASS of an object have ANY effect on it's ability to travel at a certain rate of speed in space?"
] | [
false
] | [deleted] | [
"No, increased mass only affects how difficult it is to accelerate the object.",
"However, your idea has many problems of its own. Most obviously, we can't actually fit much inside something the size of a bullet."
] | [
"well the problem with tiny probes is that there needs to be room to put all the sensitive equipment and sensor packages in there. Our technology is not yet advanced enough that we can put high-power telescopes and cameras and interferometers and whatnot into a bullet-sized object.",
"If we could build things tha... | [
"Thank you for your response. I appreciate the input. Hopefully in the next 20 years our tech will shrink to an incredible size."
] |
[
"Are male spiders aware that they are going to die after they mate, and do it anyway?"
] | [
false
] | In cannibalistic species of spiders. I guess this brings into question if a spider can know anything like this. It seems like a good starting point to define "know" in the same way that the female spider "knows" that she's going to eat the male before they start. | [
"First of all the wikipedia text about this",
"No species of spiders eats the male spider in ",
" of the cases. They just do it sometimes, some species more and some less.",
"There are different theories for this, one being that ",
"female spiders simply eat the male ones when they're small enough so that t... | [
"Funnily enough, I'm currently doing a paper about this very subject in regards to the Australian Redback spider. The male Redback rarely has more than one chance to mate in the wild so it has evolved to maximize the one (if any) opportunity it gets ",
"(Andrade. 2003)",
". The males twist during mating which p... | [
"How can we know that? Seems to me that applying the concept of human consciousness to other animals is an invalid assumption. Because they don't react or 'think' in a human way doesn't mean some sort of conciousness isnt happening. ",
"That's like a spider saying humans are dumb because we catch our prey withou... |
[
"Why are women smaller?"
] | [
false
] | it can't simply be 'because they don't need to be tall' | [
"Sexual dimorphism in the Homo lineage has been steadily decreasing. Obviously, we can't know for certain the evolutionary pressures that led to this, but we can compare ourselves to other apes and look at which ones are most sexually dimorphic and which are the least.",
"Gibbons are monomorphic and are monogamou... | [
"In many species, the male is larger than the female due to ",
"intra-sexual selection",
", which is also called \"male-male competition.\" Essentially evolution drives the males to be large to compete more effectively for a chance at reproduction. ",
"In some species, however, the female is larger; in some c... | [
"As a follow-up question, could this decrease in dimorphism lead to a higher rate of homosexuality/bisexuality in humans?"
] |
[
"Is this a parasitic worm my wife just found in her food? (X-Post from AskReddit)"
] | [
false
] | null | [
"Sorry, not the kind of thing AskScience can answer for you; I removed your post. All the best."
] | [
"Sounds good. Just curious, did you look at that thing? What the fuck is it? Would you go to the doctor?"
] | [
"Would you go to the doctor?",
"I can't answer that, for the exact reason that we don't allow posts like this. I'm a doctor, and by answering that I'm giving you medical advice, which I can't do for two reasons. 1.) If I give you my medical opinion that opens me up to be liable (it's sad that we live in a world... |
[
"Why doesn't the Earths atmosphere rotate at the same speed as the Earths surface"
] | [
false
] | Coriolis effect causes the jet streams, but surely Coriolis effect would only affect the wind direction if the earths atmosphere was not rotating at the same speed as the Earth's surface. If it is the case that the upper atmosphere is not rotating as fast as the lower then why has it not been accelerated to the same sp... | [
"On the whole, it does. Your issue is at \"but surely Coriolis effect would only affect wind direction if the Earth's atmosphere [were] not rotating at the same speed as the Earth's surface\".",
"The Coriolis effect accelerates air sideways compared to initial motion -- so, e.g., if a column of warm or moist air... | [
"Yep, that is exactly right. ",
"The issue is that latitude/longitude/altitude is a ",
" coordinate system, so moving through it induces pseudoforces that wouldn't be present in a fixed coordinate system. (The forces aren't real, they're just there to bookkeep the fact that you have to accelerate to stay on a... | [
"Thanks for your answer maybe it is my understanding of Coriolis effect that is at fault. I thought that Coriolis effect arose out of relative motion between a rotating surface and a body moving across that surface. Suppose you where to roll a ball towards the north pole. Will this ball end up curving away from no... |
[
"If an EM Drive violates the laws of physics, how/why was it proposed in the first place?"
] | [
false
] | null | [
"Because he's a crackpot and that's what crackpots do. Typically when you have a situation like this (EM drive, cold fusion, moon landing/JFK conspiracies), the idea comes from somebody (often of questionable mental fortitude) who doesn't fully understand the facts.",
"Shawyer doesn't really understand the electr... | [
"I guess I'm just shocked at how much energy and resources have actually been used in proving/disproving the EM drive. I've googled this stuff and can't find what his initial theory was that somehow justified his approach. ",
"The guy has met with Boeing, the pentagon etc and you would think there would have been... | [
"Yeah, it's pretty miraculous that anyone is paying attention to this guy. It'll die down though. They always do."
] |
[
"Hey r/AskScience, why does my ice cube tray sometimes make ice like this?"
] | [
false
] | null | [
"http://www.its.caltech.edu/~atomic/snowcrystals/icespikes/icespikes.htm"
] | [
"I'm not an expert, but this is my understanding:\nIce expands when it freezes So when you're making ice cubes in the tray, if the top 'layer' freezes first, then as the water below it freezes it's going to want to expand and push up the top layer of ice.\nNow if there is a hole or weak point in this top layer of i... | [
"This page",
" has a nice explanation of how ice spikes form.",
"They do talk about destilled water but I do get that once in a while with just tap water though."
] |
[
"Can whales use their mouths to breathe as well as their blow holes? If so can they do so independently of each other?"
] | [
false
] | null | [
"No, there is no connection between the mouth and the lungs.",
"In humans and most animals there is a shared space in the throat, the pharynx, which connects with the oral cavity, the nasal cavity, the larynx and the esophagus. In whales ",
"there are",
" two separate paths, mouth->oral cavity->pharynx->esoph... | [
"Not having your lungs flood when you open your mouth to eat while submerged is probably a very valuable adaptation..."
] | [
"Not necessarily, you can make noise without exhaling (try humming with your mouth closed and pinch your nose). Sound can travel through the whale's skull, and in fact, this is how some whales echolocate."
] |
[
"If the barycentre of Pluto and Charon lies in between the two, the do Nix and Hydra also rotate around the barycentre, or just around Pluto?"
] | [
false
] | null | [
"They orbit the barycentre. ",
"Here's a picture",
"."
] | [
"As I understand it, they technically all orbit a common barycentre. If objects are far enough away and/or small enough, though, their contribution is small enough to be effectively ignored."
] | [
"Sometimes the Earth rotates around a barycentre that's outside the sun."
] |
[
"How do prion proteins actually cause a normal copy to misfold?"
] | [
false
] | null | [
"As someone who works in the prion field, the short answer is \"we don't know.\"",
"Long answer is that prion researchers are still trying to figure out whether it is chaparone mediated (known as the protein x theory) or whether there is an intermediate structure between the classically misfolded state and the no... | [
"As someone with limited experience, the misfolded protein (the prion) is still the infectious agent. So if you took the misfolded protein and put it into a functioning cell of the same species, you'd see the formation of more misfolded proteins and the phenotypic changes associated with the prion disease. However,... | [
"Ooh. I didn't know about chaperone mediated models. In these what is the agent that can spread the disease?"
] |
[
"AskScience Panel of Scientists VII"
] | [
false
] | The previous thread is archived, but available for viewing . If you are already on the panel - no worries - you'll stay! This thread is for panelist recruitment! * The panel is an informal group of Redditors who are professional scientists (or plan on becoming one, with at least a with the field of their choice). You m... | [
"Mathematics | Numerical linear algebra/Numerical analysis",
"I work in developing and applying regularization theory for discrete ill-posed problems (and inverse problems in general). This is in application to mostly aerospace engineering and biomedical engineering problems, though I'm working in an advisory cap... | [
"Here's mine:",
"General field: Neuroscience.",
"Specific field: Cognitive neuroscience (work in a Psychology department but degree is in Neuroscience)",
"Particular area of research: Executive function, e.g., working memory and attention (using fMRI/EEG/behavioral research methods)",
"Synopsis: 2 years as ... | [
"General Field: Engineering",
"Specific Field: Biomedical Engineering, Tissue Engineering",
"Particular Area of Research: Cartilage Tissue Engineering, Application of Mechanical Forces, Chondrocyte Metabolism.",
"I have a PhD in Mechanical Engineering (Biomedical/Tissue Eng). First year post-doc in another en... |
[
"why do some shots not hurt while others do?"
] | [
false
] | I have done some searching around and it seems like it can range from what type of injection, to sharpness of the needle and, just too if your doctor is having a bad day or not. I recall a time in my younger years when a nice lady gave me a shot that didn't hurt and i asked her why and she simply said it was because of... | [
"Also the viscosity of the fluid affect the pain level. Some meications are thick and syrupy...they hurt alot more."
] | [
"Also the viscosity of the fluid affect the pain level. Some meications are thick and syrupy...they hurt alot more."
] | [
"A few reasons:",
"Some areas are more sensitive than others.",
"Needle outer diameter (OD) varies. Typical needle for IV injections are 18 gauge which has an OD of 1.3 mm. IM injections use a 22 or 26 gauge which have 0.7 and 0.4 mm ODs respectively.",
"Contents: some chemicals burn when they contact tissu... |
[
"Are there any regions of our galaxy that are vastly different from most of the galaxy?"
] | [
false
] | Aside from the core vs arms of the galaxy, what other meaningful divisions are there for our galaxy? | [
"The disc of the Milky Way has at least two kinematic groups of stars, which are called the thin and thick disc populations. The thick disc stars are generally older and metal-poor, whereas the thin disc (which includes the Sun) contains a wider spread of ages and metallicities, along with large amounts of interste... | [
"Due to the progression of fusing heavier and heavier elements, why aren't the older stars metal rich?"
] | [
"Most stars' interiors aren't fully convective, so any heavier elements produced through fusion aren't going to mix into the outer layers. This means that the outer layers should remain primordial in composition (apart from very gradual sinking of heavier elements due to gravity) for the bulk of the star's life, so... |
[
"Is there an equivalent of the permittivity of free space for gravitational waves?"
] | [
false
] | null | [
"Shouldn't there be one given that gravitational waves propagate at a finite speed? Just because the permittivity is constant in all scenarios doesn't mean there isn't a finite permittivity. "
] | [
"Yeah - Newton's gravitational constant, G.",
"Electromagnetism is often written in terms of these two parameters, the permittivity and permeability of free space, but only one of them is really free. They're constrained to combine to give you the speed of light. That's because electromagnetic waves are massless,... | [
"There was a discussion ",
"here",
" about the speed of gravitational radiation in different mediums, which is akin to what you're asking. The conclusion was that generally no there is not because there aren't positive and negative gravitational charges to re-arrange themselves like there are with electric char... |
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