title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Are mental health issues a human problem?"
] | [
false
] | [deleted] | [
"Animals (at least dogs/cats) definitely have behavioral problems that if similar behaviors were occurring in humans would be categorized as a mental neurosis. Its surprisingly common to prescribe drugs to \"neurotic\" pets to deal with behavioral problems (e.g., composure (mostly L-theanine) for OCD dogs as a pre... | [
"While my expertise doesn't cover animals, ",
"this thread",
" appears to have some helpful information in answering your question."
] | [
"There are many cases of animals in bad conditions in zoos exhibiting behavior such as pacing, obsessive grooming and self harm, which, if they were present in a human would certainly signify mental illness. ",
"http://www.usask.ca/wcvm/herdmed/applied-ethology/behaviourproblems/zooanim.html",
"These are attrib... |
[
"How do researchers check for West Nile Virus in mosquitoes, and how does that procedure work?"
] | [
false
] | null | [
"You test for the virus RNA by PCR. Grind up flies, extract all RNA, reverse transcribe to get DNA, & use primers specific for a conserved region of the viral genome to amplify that region (if its there). You can then run a gel of each sample to see if the region has been amplified."
] | [
"RT-PCR means reverse transcriptase not real time. Real time PCR is sometimes referred to as qPCR or quantitative PCR. Same basic principles, different techniques."
] | [
"Typically you use a light trap baited with CO2 (a small chunk of dry ice) to collect them. There is a fan that sucks them into the trap so they can't get out. The traps are collected and the mosquitoes are sorted by species (by trained entomologists or vector specialists). The mosquitoes of the correct species fro... |
[
"What is happening when I feel like I can hear something that looks loud but is actually silent?"
] | [
false
] | is an example. Simply looking at it induces almost a shadow of a sound (I don't know how else to explain it) in my mind. What is going on when this happens to me? | [
"What we see can affect what we hear (and vice versa!) as in the ",
"McGurk effect",
". Not only are there direct connections between primary auditory (A1) and primary visual (V1) areas, but there is plenty of feedback from higher cortical areas to earlier ones. I'm unaware of studies on implied sounds, but it ... | [
"A Bayesian view of cognition might argue that what you are describing is the general case for all of perception -- the output of perceptual processes is the combination of past experience and most likely expectations. There are several such probabilistic models of cue integration. "
] | [
"Very cool! Thank you for answering!"
] |
[
"Are birds beaks attached to their skull? If so, How are they pigmented so much?"
] | [
false
] | null | [
"Yes, their beaks are \"attached\" to the skull, but they are not bone in the standard sense. They are made from keratin, which is a fibrous protein, instead of the collagen and calcium phosphate matrix that their bones are made from. ",
"Keratin is more common to be colored than bone. I don't have the specifi... | [
"Typically bird beaks have a bone core, which is covered with a keratin sheath. It's the keratin part that has color, while the bone inside provides structural support. In the top photo on this page you can see how that yellow keratin layer sits on top of the bone: ",
"http://drvector.blogspot.com/2006/04/bird-pa... | [
"The structural part of the feathers is keratin, yeah. Bird beaks are kinda the same as rhino horns in setup."
] |
[
"This is a sample question from the Praxis Middle school Science Test. I am not pleased with the \"correct\" answer. Am I being ridiculous?"
] | [
false
] | null | [
"So, we don't do schoolwork questions... But the answer isn't D ",
" you only have ten days of data. You can't say there's no effect after ten days, which is what D is saying. Based on the data, yes, there is some effect. You can't conclude anything more specific than that. That's why A is the right answer."
] | [
"It's not really school work it's for the teacher certification test, and I'm not looking for an answer, I'm looking for a debate on the validity of the question and answers.",
"My argument is that you can only draw conclusions about the first ten days. There is no additional data other than that, so wouldn't st... | [
"You can submit to ",
"/r/AskScienceDiscussion",
" if you want, but D is saying there is no effect after 10 days, and that is not a conclusion you can draw from those graphs."
] |
[
"How efficiently do humans breath?"
] | [
false
] | [deleted] | [
"Human (and most mammalian) lungs are pretty crap at breathing. ",
"On average, humans use and absorb around 4 percent of the oxygen they take in from air ... (21 percent in, 16 percent out) ",
"--",
"The Chemical Composition of Exhaled Air From Human Lungs",
"That's why you can resuscitate people by blowi... | [
"Good stuff but your first statement is very miss-worded. 16 is 24% of 21. E.g",
". Yes that's 4% of the total air, but we'd use more & less of the available O2 if there was a higher & lower proportionon respectively."
] | [
"It depends. Your tissues can extract more or less oxygen from the blood depending on their oxygen requirements.",
"We measure the amount of oxygen bound to hemoglobin with SaO2 (oxygen saturation of hemoglobin in capillary blood). We can also measure the amount of oxygen bound to hemoglobin in venous blood as Sv... |
[
"Why nothing can go faster than the speed of light?"
] | [
false
] | null | [
"Physics"
] | [
"Physics"
] | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScience",
"To check for previous similar posts, please use the subreddit search on the right, or Google site:reddit.com",
"/r/askscience",
" ",
"Also consider looking at ",
"our FAQ",
... |
[
"What things will we simply never know?"
] | [
false
] | Obviously it is difficult to predict, but are there some things which we will never be able to uncover? In writing this question I am mainly thinking about space, and how certain restraints may prevent us from knowing certain things. | [
"For starters: The answer to your question."
] | [
"That's because it doesn't even make sense to think of irrational numbers as having a representation which can be expressed with decimals. That's like saying \"we'll never know the prime factorization of pi\"..."
] | [
"But you just answered his question with, \"The answer to your question.\"",
"Oh shi-"
] |
[
"Why are there many more species and higher density of Megafauna in Africa versus North America?"
] | [
false
] | [deleted] | [
"There are several working hypotheses that explain the disappearance of megafauna all over the world around the time of the ",
"Pleistocene",
". These are not mutually exclusive, but could have acted in conjunction with one another. The pleistocene lasted from about 2.5 mya to 11,000 years ago. Humans speciated... | [
"And it is worth noting that many animals that we think of as 'African' actually migrated from Asia.",
"TIL. Examples?"
] | [
"This is me making an educated speculation, but from what I've heard and read, the climate of Africa was much different, and much more habitable, in the prehistoric past. ",
"Imagine that the jet stream that circulates air across the Atlantic, making Florida hot and Britain rainy, was not there (per se). Imagine ... |
[
"Bayes Theorem in your field."
] | [
false
] | I've noticed a significant trend in psychological science to adopt Baysian approach to test hypothesis. For example, , , have all made compelling arguments to adopting this approach over typical analysis of variance tests. So I'm curious which disciplines use this approach in addition to standard regression or analysis of variance techniques. *EDIT-- This subreddit isn't my own way to demonstrate I know a couple things about Bayesian cognition. I'm much more interested in how other disciplines use this method. Also Bayes theorem is: P(A|B) = (P(B|A)*P(A))/P(B) | [
"phylogenetic systematists (the people who make evolutionary trees) are using Bayesian methods more and more. As far as I can tell its because the previous approaches used parsimony primarily. And we know a lot more about how evolution works than to assume nothing. For example they partition genes and functional un... | [
"no, not quite, i dont think (but I am a bit unsure what you mean, so let me know if this doesnt help). Previously, we would take every base pair change and put it in the pot and say, we will use parsimony and treat every base pair (or even morphological trait) as an independent character that may inform our hypoth... | [
"Bayesian stats are used all the time in bioinformatics. Caught me a bit by surprise coming from a frequentist ecology background but I've been told it's even working it's way in there as well."
] |
[
"Do audiovisual illusions like McGurk Effect only apply to speech?"
] | [
false
] | For example, if say someone pretended to hit their head, but in reality I just subtlety made a bumping noise, would people percieve it as if the noise came from the person who 'hit their head'? this is a dumb example, but im basically wondering is the audio illusion from overall associations of sounds with the things that make the sounds, or is it with only speech recognition? | [
"It does not. The McGurk effect is a cross modal illusion, which happens when one of your senses “hack” another. Speech is cross modal, hence the illusion, it works very well with anything visual/auditory and in theory it should with other senses (less obvious though). ",
"Here is a famous non speech example",
... | [
"It seems like a fascinating illusion; kind of wish that I were capable of experiencing it. I have autism spectrum disorder and have wondered why it's common for people with ASD to be immune to the McGurk effect, and if it has been possible to explore the reasons for this.",
"I have wondered if our tendency to be... | [
"No, for example -people often hear a thudding type noise when they see something that looks like it is landing hard and causing vibration but not actually making noise",
"If you know about the concept of neuroplasticity -it has an effect on what noises we hear and causes what are kind of illusions. Native Hindi ... |
[
"How did ancient humans get sodium?"
] | [
false
] | Humans need ~2000mg of sodium each day. These days that's easy to get because of table salt and because salt is added to most foods but how did ancient humans who ate plants and meat found In nature got any sodium? | [
"2000mg is only 2g, which is a really tiny amount of salt. I would assume that ancient humans got it from the meat they ate, since animal meat, blood and whatnot also have sodium in it. ",
"Sodium is such a common mineral in nature, you’d be hard pressed to find a food that is totally devoid of it. In fact, us mo... | [
"Sodium is everywhere including in plants. Take a look at this shot of a burning log/camp fire from my spectrometer. That big spike that you see at 589 nm is atomized sodium. That other spike at 766 nm is potassium.",
"https://imgur.com/a/bzDYc3q"
] | [
"You also don't need 2g per day, that's a guideline, and has also been interpreted to mean you shouldn't have more than 2g per day which is also wrong."
] |
[
"Use lower pressure to assist in generating electricity, possible?"
] | [
false
] | This thought popped in my head the other day but I'm absolutely certain I'm missing a crucial point. To generate electricity we very often use some method of converting water to steam which then drives a turbine, correct? Well, I was thinking, when you lower the pressure water will boil at a much lower temperature and therefore need less energy to turn into steam, right? Would it be possible to create a pressure vessel with "permanent" lower pressure and get much more steam for less energy? I apologize if this is hard to understand, English is my second language. | [
"Well I kinda see where op is going with this. In a closed system where the water is under less pressure and a turbine is also within said system and it is engineered so the water can condensate and come back to the starting point, then couldn't you just set the contraption in a slightly warm place and it will prod... | [
"Water boils faster in lower atmospheric pressure in an open system because the pressure created by expanding water vapour has some place to go. If you make some sort of closed system, the expansion of steam would increase the pressure inside your system. I don't think it's possible to make a \"permanent\" low pr... | [
"Wat? How do you propose a turbine in a dam works?",
"No. The energy required to create and maintain the pressure gradient would wash out the savings achieved by creating a larger pressure differential.",
"As a side note, the principle you envision is used for ",
"refrigeration",
"."
] |
[
"Is there always a test that can be done to check if a number is divisible by a given prime?"
] | [
false
] | For example, if a number ends in 0, 2, 4, 6, or 8, it's divisible by 2. If its digits add up to a number that's divisible by 3, it's divisible by 3. If it ends in 0 or 5, it's divisible by 5. If you keep chopping off the last digit, doubling it, and subtracting that from the remaining number, and you finally get an answer divisible by 7, the number's divisible by 7. Is there (or is there believed to be) a test like this for every prime number? | [
"Step 1: find n such that 10",
" - 1 is exactly divisible by p. For p = 7759, n = 3879.",
"Step 2: for i ranging from 0 to n - 1, calculate 10",
" mod p. For p = 7759 and n = 3879, the list begins like this 1, 10, 100, 1000, 2241, 6892, 6848, 6408, 2008, 4562…, but I won't write the whole thing out.",
"Now ... | [
"Yes. For example, the rule for 11 is \"alternately add and subtract digits\": 1234 → 4 - 3 + 2 - 1 = 2 → not divisible by 11.",
"Note that 1/11 = 0.090909…",
"Both the rule (which can be written as [1, -1]) and the fraction (which can be written as [0, 9]) repeat after two numbers. This is not a coincidence; i... | [
"I agree with your example, but the question is:",
"Is there (or is there believed to be) a test like this for every prime number?",
"And I think the answer is no. Although some of the smaller numbers have easy tricks to remember, I don't think one could say that a test exists for every prime. Besides, of cou... |
[
"How heavy is fire? If something catches on fire is it heavier or lighter?"
] | [
false
] | null | [
"Fire essentially consists of gases heated to high temperatures. If the mass of the flames is included with the mass of whatever is burning, then it makes the substance heavier, as the oxygen from the air has combined with the fuel, adding mass. However, since the hot products of the reaction are carried upwards by... | [
"Fire isn't a substance or some kind of matter, it's a reaction. (technically the exothermic chemical process of combustion), It has no weight or mass of it's own. Whatever is on fire has it's own weight, but fire, flames, combustion of any kind, does not."
] | [
"Because the stuff that's burning has weight and mass, and fire can not exist without something to burn. The fire is not being directly affected by gravity, but by how gravity is affecting everything fueling the fire."
] |
[
"What makes diamonds so strong? Would it be possible for us to synthesize a material stronger than it, or have we proved that the structure of diamond is the strongest possible?"
] | [
false
] | null | [
"...very tightly bonded to another ",
" in a rigid crystal...",
"3 = graphene, fullerenes, nanotubes, (graphite),..."
] | [
"...very tightly bonded to another ",
" in a rigid crystal...",
"3 = graphene, fullerenes, nanotubes, (graphite),..."
] | [
"You've got it mostly right, except your definition of hardness. The original empirical hardness scale developed by Moh was a good start, illustrating that a harder material would scratch a softer one. It's still relatively useful when you just want a rough estimate (\"what abrasive should I polish this tooth with?... |
[
"Have there been any conclusive studies about sleep-learning?"
] | [
false
] | [deleted] | [
"Short : ",
" (the mental process) to be able to write something in your long term memory.\nexp : Simon and Emmons 1956.\nStudent in psychology here"
] | [
"Not sure about learning by playing tapes in one's sleep, but stimulating the scalp with relatively low currents at rhythms similar to natural non-REM sleep rhythms has been shown to enhance learning of tasks learned earlier that day. ",
"citation"
] | [
"Simply put : ",
"More precisely : it gives no great effect, even no effect at all."
] |
[
"How high can a helicopter fly before the air is too thin for its rotors to keep it in the air?"
] | [
false
] | null | [
"The CH-47 Chinook twin rotor helicopter is used by the USAF to rescue climbers on Mount Denali (McKinley) in AK. It can reach an altitude in excess of 19000 to land at an elevation of around 18000. The biggest problem at that point is restarting the engines, so a special storage device directs pure oxygen into the... | [
"This helicopter landed at 8805 metres",
"This page says the record is 12442 metres"
] | [
"19000 what? Feet? Metres?"
] |
[
"Does this study imply that people will live longer if they worked out *without* taking (much) protein?"
] | [
false
] | Long-term low-protein, low-calorie diet and endurance exercise modulate metabolic factors associated with cancer risk1,2,3 | [
"I think the answers you are looking for are at the end of the paper. The authors say:",
"In conclusion, our data show that the consumption of a low-protein, low-calorie diet; exercise training; and decreased adiposity are associated with low plasma insulin, C-peptide, FAI, leptin, and C-reactive protein and hig... | [
"It should also be noted that:",
"Subjects consuming a low-protein, low-calorie diet... strictly avoided processed and refined foods (eg, partially hydrogenated oils, refined flours, sweets, free sugars, and soft-drinks)",
"So, low-protein/low-calorie + restriction of foods generally associated with weight gain... | [
"I'd be interested as well, although to clarify they didn't participate in weight training, only endurance/running exercises. ",
"I bring up weight training because every study I've come across advises to consume more protein that the RDA. ",
"http://www.jissn.com/content/9/1/54",
"For maximal muscle hypertro... |
[
"If the moon-phase is dependand on the core shadow of the earth, why is the light sometimes circular?"
] | [
false
] | What I mean is basically this: If you think about shadow of the earth, its a big cone thingy, which puts a shadow on the moon, which would explain , but why is there also phenomenon? I always wondered this. | [
"The shadows you see there aren't the shadow of the earth being projected on the moon, they are the sides of the moon which are facing away from the sun. In a full moon, the earth is \"directly\" between the sun and the moon, so the entire half of the moon that faces the earth reflects sunlight. In a new moon, the ... | [
"http://i.imgur.com/zwfWZ.png",
" \nThis will help maybe, i made it in paint :D"
] | [
"Thanks a lot! :)"
] |
[
"Why is fire hot?"
] | [
false
] | Is it the stored energy between the bonds and the “fire” is ripping the bonds apart? So then how does that work for gas. If you were burning O2 would the fire break it down to 2 Os? And if that’s the case would fire be able to burn just O. I was wondering this because I was cooking and I was wondering where all that gas went. And what it became after it was burnt. Or does it straight up become energy (the heat that you feel) | [
"Lets say a simple fuel: Hydrogen",
"If you burn that you get Dihydrogenmonoxide or simply Water",
"Another simple and more common fuel: Carbon\n(coal, wood, paper) \n Carbondioxide CO2",
"your gas stove is a little bit more complicated:",
"Propane C3H8 + 5 O2 = 3 CO2 + 4 H2O",
"it always depends on what ... | [
"Usually, breaking bonds ",
" energy, and doesn't generate any. What happens when stuff burns is that its constituent atoms combine with oxygen. This ",
" a bond, which releases energy. You can imagine this process like two magnets snapping together - it releases a lot of energy and knocks small nearby objects ... | [
"Oh that’s right, combustion reactions. Totally forgot!"
] |
[
"Why do some things burn and some things melt?"
] | [
false
] | null | [
"Burning and melting are two different reactions chemically.",
"Burning happens when the substance reacts with a gas in the air, rapidly oxidizing (oxidation is where a substance loses electrons). Usually, it is being oxidized by oxygen (hence the name). The oxidation reaction produces a lot of light, which is wh... | [
"Wood pyrolyses in an environment absent of oxygen - it decomposes into simpler molecules which are given off leaving behind a carbon rich material.",
"Some of the individual components of wood, cellulose, have been shown to melt however. This is given to that fact that cellulose has much less chain cross linkin... | [
"So, without oxygen, an object that would usually burn, such as wood, would melt at a high enough temperature?"
] |
[
"I'm trying to wrap my head around the concept of dark matter"
] | [
false
] | null | [
"It's matter which is literally dark. Because most of our techniques for analyzing things in space boil down to \"let's look at the light coming from them\", it's difficult to determine what it is. It's ",
" difficult to observe; its gravitational effects are fairly noticeable."
] | [
"We know dark matter doesn't emit/adsorb elecromagnetic radiation (EMR) because we can't see it, only its effects on other matter through gravity.",
"What dark matter is and why it doesn't emit/adsorb anything we simply don't know. The current best theory is that dark matter consists of ",
"WIMPs",
", Weakly ... | [
"Albeit while usually not in the visible spectrum, regular baryonic matter (with a temperature greater than absolutely zero) does emit EMR via blackbody radiation."
] |
[
"Why is glass not crystalline?"
] | [
false
] | My understanding of glass was that it was that its a noncrystaline solid. Which right off the bat is confusing because theres something called "crystal glass". But in addition, I was looking at [wikipedia](&) about glass ceramics, which have both crystal and crystal aspects. In particular: Glass-ceramics are mostly produced in two steps: First, a glass is formed by a glass-manufacturing process. The glass is cooled down and is then reheated in a second step. In this heat treatment the glass partly crystallizes. In most cases nucleation agents are added to the base composition of the glass-ceramic. These nucleation agents aid and control the crystallization process. Because there is usually no pressing and sintering, glass-ceramics have, unlike sintered ceramics, no pores. So it sounds like if you melt down a bunch of stuff and mix it together, it will cool down and become glass. But then they heat it up again and cool it down again, and it becomes crystal. I dont get how that works. They mention "nucleation agents", but also say "in most cases", implying its not always required. What exactly is a glass and what causes it to be that way? | [
"Glass is by definition a non-crystalline solid, meaning it is made up of molecules that have no long range order.",
"Glass can be made up of lots of different materials, silicon oxides are really common example. SiO2 can be crystalline (mineral quartz) or amorphous (fused quartz). The same is true for lots of m... | [
"When you cool down a substance, under certain circumstances, the molecules in the liquid and unable to rearrange into a nice repeatable lattice (crystal) in time. ",
"This has to do with the diffusivity of the diffusive mode associated with the relaxation of concentration gradients (or rather, the switching of t... | [
"I believe crystal glass is actually the lead free alternative to crystal."
] |
[
"How do scientists know if an animal is for sure extinct? or is it just a hypothesis"
] | [
false
] | I've kinda wondered this for years, do scientists actually know if an animal is extinct or is it more or less of a guess? I know ive read that they classify an animal is extinct when it is beyond a reasonable doubt that the last of its kind has died, but what about deep sea creatures? I can see us being able to pretty much know for sure when it comes to land dwelling animals, but the ocean is a different story altogether is it not? Thanks! And sorry if this is a silly question | [
"Interesting question!",
"There is indeed no way to know for certain. However, often heavily endangered species are conserved by human efforts. When we stop observing a species in the wild, and a last known member of that species dies, that may be the time at which we deem a species extinct. But if a new member o... | [
"There's also the case of the ",
"stick insects of Ball's Pyramid"
] | [
"It is more or less a calculated guess. It can be pretty hard to keep track of the number of animals of a certain species. However, there is also a thing called 'functional extinction'. If a species doesn't have enough members males and females can have a hard time finding eachother and reproducing (the Allee effec... |
[
"Would playing a piano in zero G cause rotation? (See assumptions)"
] | [
false
] | My five year old asked me this, I was unable to answer. We were looking at pics of astronauts in ISS on Christmas. He asked if you could play a piano in space. I said yes, but if you just tried to play the keys you'd just push off the piano and float away from it. (Assuming, if I'm correct, a floating piano, which has more mass than the player.) Anyhow, we came up with a scenario where you could strap an astronaut to a floating piano like you could strap an astronaut to a bed or an exercise machine so that playing wouldn't just make you drift away. Then he wanted to know if playing the piano would make you spin around because 1) the force on the keys and 2) the teeny little hammers. No...clue..at...all... | [
"If the astronaut were strapped to the piano, then no. Angular momentum can only be changed by an ",
" torque. The only way you could get spinning in such a scenario is if the astronaut pushed off of the piano and floated away. If the direction of the push was misaligned to his or center of mass, the astronaut wo... | [
"Thanks, my son has a lot of great questions. And I'm lucky to have a five year old that watches Big Bigger Biggest instead of Barney. ",
"I totally get what you're saying. If he pushed off, say, cross handed so he rotated his torso while pushing off, that would change his center of mass, spinning him. ",
"I th... | [
"The striking of the hammers against the strings would again qualify as an internal force, and therefore cause no bulk motion of the piano.",
"Everything inside the piano is attached to the piano in some way. The keys are attached to little hinges that let them move. The hammers are similarly attached, and are li... |
[
"Are there equations that describe the effects that a magnetic field has on a plasma?"
] | [
false
] | Preferably simple ones... I'm really bad at math. | [
"A plasma is effectively a collection of pseudo-free electric charges. A magnetic field ",
" exerts a force ",
" on an electric charge ",
" traveling at velocity ",
" according to:",
" = ",
" ",
" x ",
"If you analyze this equation, you find that free electric charges with an initial velocity tend t... | [
"Yes, to an approximation. (I don't know if \"orbit\" is the best word in this context as the trajectories are much more complicated than planetary orbits). For instance, the Van Allen belts are plasmas that are shaped by earth's natural magnetic field. The shape of the belt's effectively show the shape of the magn... | [
"Yes, to an approximation. (I don't know if \"orbit\" is the best word in this context as the trajectories are much more complicated than planetary orbits). For instance, the Van Allen belts are plasmas that are shaped by earth's natural magnetic field. The shape of the belt's effectively show the shape of the magn... |
[
"If the universe was formed in a single event, why isn't it homogeneous? As in, why do stars and planets have vastly different compositions if they originated from the same point?"
] | [
false
] | null | [
"The leading theory is that during the period of cosmic inflation, in which the universe expanded much faster than the speed of light, quantum mechanical fluctuations were collapsed and then magnified as they expanded, which lead to the fluctuations that caused galaxies and the like.",
"Planets and stars have dif... | [
"Yes we are, via spectroscopy. Different elements emit and absorb light at very specific yet unique wavelengths, and so by observing which wavelengths of light come to us from distant stars, we can tell what elements compose the star.",
"And as far as old, distant stars being relatively homogenous, I can't say fo... | [
"Are we able to determine the basic composition of very distant stars, say 10+ billion light years distant? If so, do they indeed show a much simpler and homogeneous composition?"
] |
[
"If someone tried to raise an ape as their child, in what areas, if any, would it be able to function as a normal human?"
] | [
false
] | null | [
"There is no chance of chimps speaking as they don't posses the correct vocal chords, jaw or sinus anatomy.",
"They can (disputably) be taught sign language and plenty of chimps and other higher primates have been taught to sign",
"https://en.wikipedia.org/wiki/Great_ape_language",
"https://en.wikipedia.org/w... | [
"Susan Savage Rumbaugh, the researcher who taught Kanzi (a bonobo) to communicate via lexigram, is currently raising Kanzi's son as a human child at the Great Ape Trust. His name is Teco, and you can see some of the videos of him ",
"here",
". ",
"The science behind ",
"Kanz",
"i's speech is a little fuzz... | [
"I'd suggest you read this article on Lucy the chimp, who was raised by two biologists from infancy. ",
"Some of the highlights of the experiment include Lucy being only attracted to human males and pleasuring herself using a vacuum cleaner and a playgirl magazine. Also, she reportedly acquired a taste for gin an... |
[
"Do lungs fill top to bottom or bottom to top or all at once?"
] | [
false
] | Hi ,when we inhale, does the air fills up the bottom of the lung first, or top of the lung first, or all at once first? Similarly , when we inhale, does our chest rises first, or stomach expands first, or stomach and chest expand at the same time? What about exhale? | [
"Generally speaking, lungs fill bottom to top. This is due to most thoracic expansion being caused by the diaphragm. Your diaphragm is kind of an upside-down \"U\" shaped muscle, that when it contracts, turns into a shorter upside-down \"u\", basically flattening out. That gives the lower third of your lungs, al... | [
"It really depends on posture and position and whether you (can) use your diaphragm or thorax muscles more. There are reflexes and breathing exercises that optimise air and blood flow into more segments. Normal breathing is usually a mix of the chest and the stomach expanding.",
"Normal, unforced exhalation is pa... | [
"Are you familiar with paradoxical breathing? ",
"If lungs fill bottom to top, stomach should expand first, followed by chest.",
"",
"I do not understand that when I am in my maximal inhalation, my stomach contracts but not expands. However my chest expands"
] |
[
"Why does wind feel cold, even though the air it is comprised of may be at a comfortable temperature?"
] | [
false
] | null | [
"It's basically to do with thermodynamics and the time your body is in contact with the surrounding air. Humans cool down by dilating blood vessels and effectively making their skin as hot as possible. When two materials with different temperatures come into contact, the hotter one transfers heat onto the colder on... | [
"Same answer as the previous times it was asked. The rate of thermal heat transfer by conduction increases with the temperature difference. Bigger temperature gradient, faster heat loss. That means the temperature of an object, initially at 30 degrees above than room temperature, will drop by 10 degrees more quickl... | [
"Heat transfer will occur if there is a gradient. So generally hot->cold or cold->hot. If you continually pass air over your skin, the air won't reach equilibrium with your temperature, so it will feel much colder. "
] |
[
"Do we know enough to figure out where viruses came from and what micro-organisms might be their closest relatives?"
] | [
false
] | [deleted] | [
"Viruses aren't really related to microorganisms because they aren't really organisms. A virus and a bacteria are fundamentally different enough that it isn't likely that they share a history anytime in the last billion years."
] | [
"agreeing the connections are still very obscure it is important to remember that viruses are not composed of living cells. The only means of viral replication is by way of host cells utilizing the lysogenic and lytic cycles. "
] | [
"no, the connections are still obscure. all micro-organisms use DNA, while viruses use RNA-based genomes. the two might have evolved separately, or one might have come from the other. but the common ancestors (those that depended even more on RNA for catalysis and information storage than modern cells) are eithe... |
[
"What have we learned or plan to learn from Ingenuity (the helicopter on Mars)?"
] | [
false
] | Pretty simple question. I'm all for remotely flying a helicopter on another planet , but I got curious what we could learn from it. Geology, thin atmosphere flight, etc. I'm a layperson and I'm curious what the plan is/was. | [
"What they intend to learn from Ingenuity is how to build and operate a helicopter that can fly autonomously on Mars, and what problems they will encounter from doing so. The idea is to use this knowledge to build more aircraft that can be used for gathering data and scouting the best paths for rovers.",
"You hav... | [
"Wikipedia has an overview",
"."
] | [
"Could be used to safely land rovers in the future? Or would it need to be too big?"
] |
[
"What are capacitors used for and how do they work?"
] | [
false
] | I know that capacitiors are found in most electronic circuit boards and I understand that they store electricity. But how do they store electricity, and why would you want to store it when you can use batteries? What else do they do with it? So many questions. EDIT: Spelling. EDIT 2: Thanks for all the answers! :) | [
"In modern terminology, the phrase \"storing electricity\" is essentially meaningless. The term \"electricity\" is ambiguous and might refer to current, or voltage (potential), or energy, or power, or charge. Capacitors store energy in an electric field.",
"As a shorthand, we often say that capacitors \"store cha... | [
"Just to clarify, in a more general sense, a capacitor is defined as an object that stores charge. Colloquially, people refer to capacitors as the circuit elements that have a net neutral charge, with oppositely charged elements; this is delineated as 'mutual capacitance' when context doesn't make it obvious ( ",... | [
"A capacitor works the same way a mass does in a mass-spring-damper. In dynamics, it sources a current to resist changes in voltage, and can source more current if it has more capacitance. This is the same as a mass generating a force to resist a change in velocity in a 1D system."
] |
[
"If water is clear and water vapor is white, why are storm clouds grey?"
] | [
false
] | Is it from the condensation of the water drops in the clouds blocking out light from the sun? Or is it possible to create a grey/black form of water vapor? | [
"Water vapor is not white. Water vapor is clear. Clouds are made of small droplets of liquid water or solid ice; those small particles are what appear white.",
"Clouds are white due to ",
"Mie scattering",
". Tiny particles in the air tend to make light \"scatter\", since there are so many small individual su... | [
"Mostly. Due to the fact that liquid water has a slightly blue color, there is some absorption of long wavelengths that give clouds a blue and ",
"sometimes greenish tint",
". But the main reason dark clouds appear \"dark\" is because a lot of light has been scattered away."
] | [
"Nope, that's a very common misconception! ",
"Water is indeed blue on its own",
", due to the fact that it mildly absorbs red light."
] |
[
"Did the speed of the JWST decrease between yesterday and now? Why? How?"
] | [
false
] | Look how the speed decreased from launch. It reached 9km/s at launch. But now it's at 1.8km/s. How does it work? | [
"Earth's gravity is doing the trick. If it moves faster than the speed of a circular orbit, then orbital dynamics mandate it will gain altitude. At this point the force of gravity will not be perpendicular to the velocity, so it will pull backwards from the telescope, causing it to slow down. Another way to reason ... | [
"It's what you can remember from physics classes at school - kinetic energy gets exchanged for potential energy when you're moving further away from gravity source. If you throw something up then it will slow down up until it stops entirely when reaching the highest point (and then starts moving faster and faster a... | [
"I was confused because I thought that the telescope will continue to accelerate until it reaches the midpoint of the journey",
"What would cause that? :) To accelerate you need either to be dropping down into gravity well (aka: falling) or use propulsion (aka: fire engines).",
"Will it start to accelerate when... |
[
"Is one side or spot of the Sun known to be hotter than the rest?"
] | [
false
] | null | [
"The Sun varies massively in temperature across the whole disk but not really in the systematic way you are implying (cooler on one side). Instead it has a fairly complex pattern at all scales, from both very small fine scale variations to very large changes in temperature that span across huge fractions of the Sun... | [
"Looking from a long distance away, the Sun has the same effective temperature from all different directions, since it is close to being an ideal sphere in shape.",
"However, there are some stars which spin much faster than the Sun, and they bulge out around their equator (looking like an M&M or a Smartie), so th... | [
"How would our solar system be changed if our sun acted like the mentioned star Vega?"
] |
[
"I need to come up with a 5th grade science lesson plan. What are some topics that are important for a kid that age to be exposed to?"
] | [
false
] | My task to is to design a science lesson plan that I will present to two classes of 5th graders. The lesson plan must include an experiment that the kids will perform themselves (in groups of 7). I would prefer to design an experiment beyond what is shown in every classroom. So what are some topics in science that you feel like more young people should have a better understanding of? My safety considerations include no chemicals beyond what can be purchased at a grocery store and no current in excess of normal wall current. | [
"Mix yeast with varying amounts of sugar and put it in an upside down test tube, then measure the size of the bubble as a function of time and sugar concentration."
] | [
"Your best bet is to ask a 5th grader what is interesting to them.",
"Science (the scientific method, more specifically) is about asking questions and logically approaching the answer. You need to get kids away from thinking that \"science\" is only happening when there are colored tests tubes and barometers aro... | [
"evolution"
] |
[
"Is the current lethal injection the most humane way to kill someone?"
] | [
false
] | null | [
"The answer to this question depends on knowing what is the least painful or frightening to kill a person. Science can answer those questions."
] | [
"There's an interesting documentary ",
"How to Kill a Human Being",
", where a British journalist investigates the science and ethics behind state execution. He pushes himself to the brink of death several times to determine the most humane way to perform an execution. "
] | [
"If you want most painless method, high caliber bullet to the head would be it. Anything that blows your brains out faster than neurons can signal is painless. Of course, giving free opiates and/or other medication before the execution to take out the anxiety would be even more humane. ",
"even more humane opti... |
[
"Why is the allergic response different than the immune response?"
] | [
false
] | In my physiology class, like most classes, we're learning that the allergic response is a hypersensitive response to nonpathogenic antigens. We learn about it as a facet of the immune system. But if it's the immune system? Why isn't it a normal immune response? If it's only for nonpathogens, why is there a response at all? The symptoms are so different, I can't tell why the allergic response exists at all--it doesn't actually seem to do anything to support the goals of the immune system. | [
"I learned in my EMT class that an allergic reaction is just an extreme reaction to something, it's because your body sees the allergen as a foreign body that doesn't belong and it tries to fight it despite it not being harmful. So basically from my limited understanding it's kind of an error that the human body is... | [
"There are children born and breastfed who develop allergies. So I doubt it's about eating the wrong food. There's a chance it's related to gut flora."
] | [
"Very generally the processes in a normal immune response and an allergic response are the same, the problem is that in an allergic reaction the body is targeting a non-dangerous molecule (e.g peanuts). In the case of autoimmune diseases (e.g diabetes or rheumatoid arthritis), the immune system targets its own cell... |
[
"Is there an stoping point for radioactive half life decay?"
] | [
false
] | Learning about the decay of isotopes in high school, wondering if there was a point where the process stops? Maybe when there's only one atom left? Please enlighten me. | [
"Take one atom. What does a half-life mean for that one atom? Well it means that in one half-life there's 50% chance of decaying over that stretch of time. So when you have a ",
" of atoms, statistically half of them decay within each half-life. But when you get to that last atom, you keep proceeding through time... | [
"There's a series of fun science activity to demonstrate this with ",
"candy",
" although I modify it to graph each type of candy's half life as to simulate and discuss that different elements/isotopes have different half-lives (peanut M&Ms, plain M&Ms, skittles, etc.)"
] | [
"Technically, it will stop when that last atom decays. However, we are dealing with such huge numbers of atoms (remember a mole of a element has 6.0221415 × 10",
" atoms) that, effectively, this point is never reached. The real limit on radiometric dating is our ability to measure small amounts of material."
] |
[
"What gives an object its colour? What exactly is happening at the molecular/atomic level?"
] | [
false
] | null | [
"Photons are either absorbed or reflected by the material. Our eyes detect these photons and register them as different colours. Longer wavelengths are “warmer” colours, shorter wavelengths are “colder” colours, from red through violet. White is when every photon is reflected (though a pure white is pretty impossib... | [
"It’s about the energy and corresponding wavelength an object has. For example carrots contain β-carotene. β-carotene has a linear conjugated π electron system (a kind of chemical structure in which you have a single and double bond x times). The electrons along the system moves similar to a 1D infinitely deep pote... | [
"Could you please elaborate a bit more?"
] |
[
"When studying the brain, implanted electrodes are used to measure/model activity but wouldn't we need to know which neurotransmitters are being used in that activity?"
] | [
false
] | null | [
"Right, they do not measure neurotransmitters directly. Understanding what is going on with neurotransmitters would be a different level of explanation (a different question with a different answer). ",
"Think of it like asking \"how does texting on your phone work?\" You can answer that in lots of different ways... | [
"Using your texting analogy, would it be fair to say electrodes let us know who is texting who and when, but we don't know the message that's being sent?"
] | [
"No. Neurotransmitters aren't the message themselves. Information is carried in the patterns of neural firing and connections between neurons. There's nothing special about the neurotransmitters."
] |
[
"Will the whole universe eventually become one big black hole?"
] | [
false
] | null | [
"No - the Universe could, in principle, end up in a \"big crunch,\" collapsing back down to nothing, but the expansion is presently accelerating, and unless that somehow stops, there's no recollapsing."
] | [
"The universe has no center. Even an object with the mass of the observable universe wouldn't be enough to stop objects at the edge of the observable universe from receding."
] | [
"There are different theories. One of them does speculate that eventually gravity will overcome whatever force has expanded our galaxy and eventually (a very long time even cosmologically speaking) will contract back in again.",
"Right now the most accepted theory seems to be that the universe will die a \"heat d... |
[
"Why is there no perception of depth while we look up at the sky?"
] | [
false
] | [deleted] | [
"One of the ways that depth is perceived by the difference in convergence of your eyes when looking at different objects.",
"Right now, I'm going to guess, and presume for the purposes of this example, that you have a screen 1m away from you, and a wall 2m away from you. I'm also going to assume that your eyes ar... | [
"Most of our methods of ",
"depth perception",
" are minimized at large distances, the sky being an extreme case of this. Others just aren't relevant for the night sky.",
"One special case is the ",
"moon",
" on the horizon (even if various explanation are debated...)."
] | [
"I'm not sure I agree with you about the thing with the moon at the horizon - this isn't depth perception - this is size perception."
] |
[
"What would it feel like if a human were in a superposition?"
] | [
false
] | [deleted] | [
"What..what are you even asking?"
] | [
"Yes, but I'm not quite sure you understand what it is, based on your question. Things are only in quantum superposition until they are measured, but when you are referring to stuff outside of the quantum level, superposition doesn't actually apply. In fact, Schrodinger's Cat was originally posited as a thought exp... | [
"Do you know what a quantum superposition is?"
] |
[
"Why are the solar panels on ISS different from the ones usually seen here on earth?"
] | [
false
] | null | [
"Space is a very harsh environment. Anything sent into space will likely need to be highly customized in order to function for any length of time.",
"\nFirst is weight. Sending mass into space is expensive, so lowering weight is a high priority. The solar arrays for space missions are made much thinner than cheap... | [
"From the wiki: ",
"",
"\" ",
"Gallium arsenide",
"-based solar cells are typically favored over ",
"crystalline silicon",
" (residential) because they have higher efficiency and degrade more slowly than silicon in the radiation present in space.\"",
"",
"Also the ISS array wouldn't have a protect... | [
"I don’t know, but I’ll be sure to ask the next time I talk with some of the solar array folks I know.",
"\nThere’s a good chance the answer is ‘no’. The more efficient, modern semiconductor materials tend to be less reliable in high radiation environments. That may not apply to solar cells though. "
] |
[
"Isnt it strange that both Neptune and Jupiter have a single great storm on their surface?"
] | [
false
] | Is there some phenomenon or set of processes at work in a gas giant that would favour a single, long lived, localised storm rather than a series of smaller randomised ones (like our hurricanes)? Neptunes Great Dark Spot: | [
"mo' money mo' problems (solved)"
] | [
"Some research was done about twenty years ago where some team actually spun a disk of fluid, maybe while also inducing a temperature gradient across it. I'm fairly sure I read about it in Scientific American, but I can't find it now.",
"At a significant range of speeds and temperature gradients, they observed a... | [
"It's interesting. We don't yet know if it's strange. The difference being that they are (to the best of my knowledge) active areas of research. But we could find that the dynamics of gas giants somehow favors long-lived storm (so they wouldn't be strange)"
] |
[
"Are there any studies that have analyzed risk adverseness varying by location in the United States?"
] | [
false
] | [deleted] | [
"People in certain parts of the country are more accepting of certain risks, but it is difficult to compare these risks. ",
"For example people in hurricane prone regions are more accepting of hurricane risks while people in earthquake prone regions are more accepting of the earthquake risks. Similarly people in ... | [
"On mobile so I can't do a thorough search for a link, but I have heard references to a study that linked risk aversion to political identity and that varies with location so I wouldn't be surprised if they mention it deep in the paper. ",
"So if you're looking and not having any luck, try search terms about pol... | [
"That's definitely a good idea but I do think you might run into issues trying to tease out who doesn't have insurance by choice vs. those who don't have it because no insurance company will offer it to them at an affordable price (if at all).",
"There are certain places, particularly flood areas, where insurance... |
[
"Is there a relationship between being gay and being transsexual?"
] | [
false
] | According to this report the incidence of lesbian, gay and bisexual identity among transsexuals is higher than that of the cisgendered. Is there a similar pattern in regard to gender expression? Meaning that there is a statistical higher incidence of gender play among transsexuals? Would this not mean there is a biological relationship between these characteristics? What would we mean by a biological source for gender expression? | [
"As far as is well-established we know these important things on the subject (not all-inclusive, just data I am familiar with, obviously):",
"1) Gender identity is significantly programmed into a human being since before demonstrable conscious thought can take over. Baby boys have habits baby girls don't and vic... | [
"2) Homosexual tendencies are separate and distinct from transsexual tendencies. ",
"But the report I cited says otherwise. What is the gay or bi identity rate among transsexuals? Note I'm not saying it is a direct correlation. I'm saying there is a relationship. The two rates would need to be more similar. Altho... | [
"The report you found suggests what exactly? I am saying homosexuality is independent of transexuality. That your gender identity is not dependent on who you find attractive, that the two are universally distinct. This is supported by the overwhelming numbers of homosexual individuals who feel correctly gender a... |
[
"Why is it dysfunction and not disfunction?"
] | [
false
] | [deleted] | [
"It says this post has already received two comments but I don't see them, so I will add mine.",
"The difference between the dis- prefix and the dys- prefix is minute but significant nonetheless. ",
"\"Dis\" is Latin and means \"apart\" or \"opposite of\"; so working with your examples you have:",
"approve an... | [
"That is an interesting observation; from a strictly etymological viewpoint you would think it would have to be dysability seeing as disability implies a complete lack of ability as opposed to an impairment or limitations.",
"Here is what I found in the medical dictionary of the Free Dictionary",
":",
"\"dis-... | [
"This all makes perfect sense, until you think about the word \"disability\"."
] |
[
"How are a non-planetary nebulas created?"
] | [
false
] | null | [
"In short, gas in galaxies cools until it is able to ",
"collapse",
" under it's own self-gravity. The reason it needs to cool is because thermal pressure support prevents counters the gravitational force. As the cloud starts to collapse under gravity, it heats up, so it actually needs to keep cooling.",
"Coo... | [
"Gravitational collapse. You’ll have to specify what you’re asking about in particular though.",
"‘Planetary nebula’ is a notoriously bad name, coined before we knew what they were and for some reason not ditched. They are actually ionized gas expelled highly evolved (meaning nearing the end of their lifecycles) ... | [
"Additionally, nebulae are shaped by the stars they produce. Once denser knots of dust and gas start to light up as stars, these stars produce radiation which ionizes and exerts pressure on the surrounding nebular material, carving out huge bubbles and voids. One of the best examples of this can be seen in the so-c... |
[
"Evidence for Existence of Planet \"Vulcan\""
] | [
false
] | Since the newly discovered planet around Alpha Centauri B is probably far inside the goldilocks zone, this question occurred to me. Is the fact that many of the planets we find have very short orbital periods, is this circumstantial evidence of a planet "Vulcan" that was once inside the orbit of Mercury? UPDATE: I'm not saying that there is currently such a planet. I'm asking is this circumstantial evidence that such a planet once existed before spiralling into the sun. | [
"The reason we tend to find planets with short orbital periods is that our detection methods are biased towards them. Planets closer to the star exert a stronger gravitational pull, making it easier to detect the change in the star's velocity."
] | [
"This bias is also present in the transit method of detecting planets, since you need multiple observations of transits to confirm detection, and a shorter orbital period means it will take less time to get those multiple observations."
] | [
"No, it's not circumstantial evidence for this. First, why would it have spiraled in if it had existed? In fact, we have every reason to think, based on the laws of physics, that such a planet would not have spiraled in. Secondly, there are the points elsewhere in this thread about planetary detections being bia... |
[
"Is ATP transported between cells, or by the bloodstream? or at all?"
] | [
false
] | [deleted] | [
"A review from 1982 that looked at different studies on ATP said data suggests that ATP can cross the cell membrane.",
"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2595991/pdf/yjbm00108-0006.pdf",
"More recently there was a review of ATP release in blood vessels. ",
"https://academic.oup.com/cardiovascres/ar... | [
"Additionally, ATP can be loaded and released in a vesicular mechanism from neurons.",
"\nSawada, K., Echigo, N., Juge, N., Miyaji, T., Otsuka, M., Omote, H., et al. (2008). Identification of a vesicular nucleotide transporter. Proc. Natl. Acad. Sci. U.S.A. 105, 5683–5686. "
] | [
"ATP has a variety of roles as a signaling molecule that communicates the health of nearby cells among other things, which is most of what ",
"/u/Aelintari",
" 's second link is about. In this role the concentrations are tiny.",
"Large amounts of extracelluar ATP are both a cause and a result of inflammation,... |
[
"What is the minimium number of base pairs need to act as a \"primer\" for PCR?"
] | [
false
] | I'm having trouble with RT-PCR and can't seem to find my problem. I have to redesign primers because the previous Grad student used Taqman and I am using Sybr green. any tips for primer design would also help. Yes I googled this, yes I asked every professor, yes I looked in the text book. | [
"The minimum depends on a bunch of things. The smaller the primer, the lower annealing temperature (melting temp = Tm) you use. The lower temperature and the smaller the primer, the higher the probability for nonspecific binding and mis-priming. Usual primers are >18 bp to give a gap between annealing and extension... | [
"This.",
"You may also find it helpful in switching from TaqMan to SyBr to change the positioning of the primers so that one of them crosses an exon-exon boundary in the mRNA/cDNA you are targeting. A lot of TaqMan users do this with the probe instead, so it's possible that you are amplifying genomic DNA in your ... | [
"I'm not sure - maybe in human/mouse. I've always worked in non-model organisms, so I align genomic and cDNA and target primer design to the boundary region in ",
"primer3",
"."
] |
[
"I'm curious, how do we know about the position of a celestial object millions or billions of light years away ?"
] | [
false
] | null | [
"All of our distance measures start and are calibrated by parallax. The greatest parallax we can observe is when the Earth is at opposite ends of its orbit (observe a star’s position once, then again half a year later). The most accurate parallax measurements have been done by the Hipparcos mission and its follow-u... | [
"Parallax is only useful for objects very very close to us within our own galaxy."
] | [
"Parallax is only useful for objects very very close to us within our own galaxy."
] |
[
"How does an entire power grid fail, as in India right now or in the US and Canada in 2003?"
] | [
false
] | I was wondering what exactly causes the failure of an entire power grid, and why fixing it is not as simple as selectively switching off parts of the grid and hooking them up again iteratively. Are there pieces of equipment that are destroyed in the process? | [
"Nuclear engineer here (I work in a power plant).",
"There is a lot of talk about cascading failures. To understand why they are such an issue, you need to remember two things. First, heat generated in lines, transformers, breakers, is proportional to current drawn, and second, there is a very strict balance betw... | [
"This is why I come to AskScience. An informative, full, yet ",
" answer. I knew that it was about load vs generation, but not the specifics, and this answer made perfect sense and gave me a sense of how it actually goes down. Upvotes for you!"
] | [
"Generally when a failure of that magnitude happens it's several bad things happening all at once. Any large process or system, especially one THAT large, has \"catches\" in place so that if something causes failure in one part of the system, that failure won't happen in other parts of the system. However, if tha... |
[
"When does Hooke's law break down?"
] | [
false
] | Hooke's law is the approximation that the spring force is linear with respect to displacement. However, that's just a first order approximation, and obviously, springs can become deformed (just ask all the clicky pens I've disassembled.) I was wondering, how true is this approximation for most springs. | [
"Good question!",
"Hooke's Law is simply a linear (1st order) approximation of the actual behavior of springs, and for most common conditions it holds true. That's what makes it useful. You could imagine that as we push any conditions to extreme, then the linear approximation will no longer hold. The most obvious... | [
"Every spring (or other elastic material) has some maximum force after which it will break or become deformed. This force is given by:",
"F",
" = (Ed",
" (L-nd))/(16(1+ν)(D-d)",
" n)",
"where:",
"E is Young's modulus",
"d is the spring's wire's diameter",
"L is the spring's free length",
"n is the... | [
"You can type all Greek letters by doing the html entity for them: &<letter>;. Like π is π. To capitalize just use the uppercase -- δ is δ but Δ is Δ."
] |
[
"Random vs. systematic error"
] | [
false
] | I understand the basic concepts of the two different types via wiki and other sources but I'm really struggling with some examples. like if you only take one measurement would it be considered random even though if you took multiple measurements it would be systematic? what kind of error would it be to make multiple dilutions using volumetric flasks instead of just one? really any help would be appreciated, I can give specific examples if that would help you help me. THANKS! | [
"For systematic error visualise a ruler that has somehow been miscalibrated so it starts on 0.1 instead of 0 or a set of scales that has been miscalibrated so it says -0.1 kg when nothing is on it.",
"For random error think of background noise that would make a microphone produce slightly higher or lower sounds t... | [
"Systematic errors are due to errors in measurement. They can be reduced by techniques such as ",
" equipment calibration, etc. ",
"Random errors are due to the random nature of the thing being measured. They can sometimes be reduced by techniques such as taking multiple measurements. ",
": Corrected statem... | [
"Are you sure of what you're saying? Systematic errors, by definition, cannot be reduced by taking multiple measurements. "
] |
[
"What's the biggest change in a single species caused by evolution in recorded history?"
] | [
false
] | null | [
"Evolution generally requires tens of thousands of years to make noticeable progress; despite shaping all life on our planet, in broad strokes it is a fairly weak force. Thus, it takes far longer to see big change in populations than the length of time we've been writing things down. Not to mention, most ancient te... | [
"None of this is really natural selection though, since none of these scenarios would occur were it not for human activity.",
"Ehh, I disagree. It's still natural selection if the selection is happening stochastically, as opposed to a person actively choosing what individuals get to contribute to the gene pool. T... | [
"So a lot depends on how you define evolution here. Are you talking purely natural processes or do we include ourselves as an agent of evolution with our selective breeding and even mutation breeding in plants. ",
"All of our agricultural plants and animals have had many, many generations of Selective Breeding ap... |
[
"How is Titan able to retain an atmosphere?"
] | [
false
] | From what I’ve heard, Titan has a nitrogen atmosphere much taller than our own due to its lower gravity. It sounds like it has a pretty tenuous hold. Is this a permanent feature? How is it not stripped away by solar winds? | [
"It is far away from the Sun, not much solar wind, in addition it is protected by Saturn's magnetic field.",
"It is cold, the molecules have a low average velocity, they are unlikely to escape even with the lower escape velocity."
] | [
"Plus something is replenishing it, in particular the methane. It's probably reasonable to assume some kind of cryovolcanic activity."
] | [
"Why can't the same be said for Triton or Io then? Are they just too small?"
] |
[
"What exactly do muscle building steroids do and why are they bad for you?"
] | [
false
] | null | [
"Not true. at. all.",
"Anabolic steroids, as MaxSoftcore mentioned promote the synthesis of muscle tissue. They do not give you more energy, nor do they make you produce more testosterone. Anabolic steroids will artificially offset the bodies' natural homeostasis which results in a DOWN regulation of testostero... | [
"Not true. at. all.",
"Anabolic steroids, as MaxSoftcore mentioned promote the synthesis of muscle tissue. They do not give you more energy, nor do they make you produce more testosterone. Anabolic steroids will artificially offset the bodies' natural homeostasis which results in a DOWN regulation of testostero... | [
"So why is that bad for you. I mean I personally don't want to shrink my testicle but if someone else doesn't mind whats to stop them?"
] |
[
"Planets can have rings. Can stars have the same sort of rings?"
] | [
false
] | I don't think Sol's asteroid belt would count as a ring because, I assume, it's not nearly as dense as the rings around Saturn. Can a star even have a ring so dense as to be very visible? Thanks in advance! | [
"It is definitely possible. ",
"First, a solid celestial body would have to enter the star's sphere of gravitational influence. Then, it would have to pass through the Roche limit. That's the distance where the tidal forces will rip the object apart. ",
"If the object wasn't on a collision trajectory with the s... | [
"Depends on the mass of the star. The Roche Limit is directly proportional to the mass of the star. ",
"But, if there are planets in the star system as well, I doubt the ring would last long."
] | [
"If you don't think the asteroid belt counts as a ring (it ",
" the actual solar equivalent of having a ring), then not really. The reason it can't have a dense ring of small particles in very close proximity like Saturn is because of how stars are born. Once the accretion disc has built a body large enough to be... |
[
"Are the numbers of nucleotide pairs between healthy humans of the same gender the same?"
] | [
false
] | I read that the number of nucleotide pairs in each set of our chromosomes is around 3 billion. Each person has 2 sets (in most cells), each from one parent, so the total would be 6 billion nucleotide pairs. I think this number assumes that the chromosomes are unduplicated, otherwise the number would be double, but I'm not sure. Please correct any points above if I'm wrong. Assuming the above is correct, then I would have 6 billion something nucleotide pairs in all cells except germ cells. Does everyone else of my gender (M) who is healthy have the exact same number of nucleotide pairs as mine? My guess is it should also be 6 billion something, but I wonder if every healthy individual of my gender shares the exact same number. Please add extra useful information if possible. I'm not a trained biologist. I just get overly interested in the subject as I plan to get my genome sequenced. Thanks! | [
"The number would be close but not identical, it actually isn’t going to be identical between all of your cells either. You have telomeres at the ends of your chromosomes which are basically just extra DNA to make sure u don’t lose anything important. These can vary in length due to a number of reasons (and can act... | [
"No, the number of base pairs won't be exactly the same. Even in healthy individuals there are different numbers of what we call \"tandem repeats\" - these are small sequences of DNA that can be repeated varying numbers of times.",
"To illustrate, ",
"Fondon and Garner (2004)",
" found that varying numbers of... | [
"yes, close but not the same number. The differing numbers of nucleotide pairs and the way their organized is what causes genetic diversity in humans and all other animal species."
] |
[
"The heatwave in India has killed over 2,000 people with temperatures between 40 & 48 C. Few years back a lethal london heatwave was ~32 C. I live in a country where it's not unusual to get to 52 degrees Celsius. Usually it's between 45 and it's a mild inconvenience. What's happening?"
] | [
false
] | null | [
"I bet you don't have to work outside for 10 or 12 hours in that heat though? And I bet you've got a top of the range air conditioning system? ",
"I doubt a lot of the poor in India can afford to just stay indoors under expensive air conditioning.",
"And in London - not many people have air conditioning. Not on... | [
"Humidity can be a huge factor as well.",
"If the air outside has low humidity your body can easily cool off."
] | [
"Fair point. Just to be clear and as a response to your answer, I wasn't trying to belittle the issue or any of the deaths. Just curious as we play football in that heat sometimes and at the end we're thirsty and sweaty. But yes I do spend more time indoors than outdoors, but there are days when I'm exposed to the ... |
[
"What is actually happening while I sleep? And why do I need it?"
] | [
false
] | I keep hearing about how the brain "repairs" itself or it "cleans itself up" and all sorts of stuff that sounds like mumbo-jumbo to me. I get that it probably is doing something like that but when someone says "repairs itself" I like to picture my brain physically healing and that just sounds silly. And when I hear cleaning itself up I picture fans blowing the dust out. What is going out, without getting too technical? I am not biology student but I'm no idea either. I love reading about things like physics around here because I can understand them without getting into the technical aspects as a non-science student. What happens during sleep, and why does my brain require me to sleep? | [
"I can only speak about certain specifics regarding the neuroscience of sleep:",
"You regenerate ATP during slow-wave sleep. Vital for neural functioning",
"You consolidate memories, probably! It's not entirely clear, but is very, very likely.",
"Without sleep (and because of ATP and a few other things), you'... | [
"But what about things like that sort of crazy sleeping pattern people can learn to have? The one where they break up their sleeps across the day and get much less sleep yet insist they are healthy while doing it? Something about maximizing the amount of REM sleep?",
"It can be nonsense.",
"Both REM and SWS sle... | [
"I will see if I can find the book in a store and flip through it on a lunch break or something, though it's not really a subject that deeply interests me. It's just a question I can't get out of my head lately. "
] |
[
"Is the plane of Earth's rotation around the Sun parallel to the plane of the Sun's rotation around the center of the Milky Way?"
] | [
false
] | If not, what is the angle between them? If so, is it just a coincidence? | [
"In this ",
"image",
" the red line repesents the plane the planets orbit in, and the yellow line the milkyway, was made using ",
"stellarium",
"."
] | [
"For the lazy, ",
"the ecliptic plane is off by about 60",
" to the galactic plane",
" (another way to phrase the OP's question)."
] | [
"Is it strange that this is the case, ie, are most planetary systems' ecliptic planes not-so-close to the galactic plane? Also, does the sun rotate on an axis nearly perpendicular to the the solar system's ecliptic plane?"
] |
[
"Are extra spatial dimensions something we can accurately perceive with a trained mind?"
] | [
false
] | On that note, it seems the only way to begin to perceive these dimensions is by seeing wireframe shapes in constant rotation. I feel that there is a way to perceive these in our mind with extra mental senses, maybe artificial senses of time/space and seemingly impossibly connected points in space (like how worm holes are theorized in sci Fi movies) that we could conjure in our imaginations with enough focus and mental exercises. Is that how you high level physicists are trained to understand quantum physics and string theory? | [
"Yes, a trained mind can perceive spatial dimensions of any dimension! You just have to train yourself to look at these spaces through the lens of equations, rather than trying to perceive it with the mind's eye. ",
"The mind's eye is not good enough to really understand 3 dimensions, so adding more will just inc... | [
"I entirely agree with ",
"/u/functor7",
" that the best option is to turn to equations and other more abstract representations that scale better with increasing dimension. However...",
"There are other visualizations of higher-dimensional objects than just wireframes that are good to know, but most stop bein... | [
"We define ordinary 3-and-lower-dimensional spaces using mathematics too, so one should not be so surprised that the same approach works for higher dimensions as well. :)"
] |
[
"Is it possible to know what sound is recorded by only looking at data graphs?"
] | [
false
] | [deleted] | [
"There's actually a word for what differentiates the sound of a piano from the sound of a bell (assuming they're the same note). It's called ",
". (pronounced TAM-BER)",
"http://en.wikipedia.org/wiki/Timbre"
] | [
"It's pretty easy to tell a bell and a piano apart by visual examination. Bells are quite simple - basically a sine wave at a particular frequency, which decreases in intensity exponentially over time. A piano has a much more complicated waveform, due to additional resonances in the body of the instrument, the othe... | [
"As a recording engineer, I can tell you that after looking at waveforms for hours, it becomes easy to see which instruments are which by the waveforms, even discerning which kick drums are which, etc. ",
"As for seeing a waveform without first hearing the sound to associate it, I suppose it could be done. Each i... |
[
"I have learned that schizophrenia onset occurs very suddenly in approximately a person's twenties. Has there ever been a reported case of someone emerging from their condition just as rapidly, to go on and lead a completely normal life?"
] | [
false
] | [deleted] | [
"When interviewed carefully, families of schizophrenic patients are often able to describe vague and subtle changes that preceded the frank onset of psychosis by months or even years.",
"There are people who respond well to medication and can live fairly normal lives. Brief psychotic spells that do not recur migh... | [
"Yes. To mention some other things, schizophrenia is a pretty hefty diagnosis, so I imagine there's quite a bit of caution whenever it's diagnosed. If brief psychotic disorder is too short, then you may want to consider looking into schizophreniform disorder--that requires symptoms of more than one month, but less... | [
"Fascinating. Thank you."
] |
[
"Why is Mitochondrial Eve dated to 150-170,000 years go?"
] | [
false
] | null | [
"We know how fast genetic changes occur. If we look at all mitochondrial dna and count the number of genetic differences between all we have cataloged, we can follow backwards to they would all effectively be the same. Depending on fastest estimates and slowest estimates of genetic drift, it's roughly 150k-170k yea... | [
"Because you are missing part of the definition. Mitochondrial Eve is defined as the most recent maternal common ancestor."
] | [
"The title of \"Mitochondrial Eve\" is defined as the ",
" matrilineal common ancestor of all living humans. If we trace the ancestry of all living humans through their mother's side, all lineages pass through M.E. before they get to any generations further back, and once you're past M.E. all the lineages look id... |
[
"Imagine a large air filled balloon tethered to the bottom of a body of water. It is completely submerged. There will be a tension on the tether. What mechanism could be used to turn this into useful energy and can you estimate how much energy per volume of air it might yield?"
] | [
false
] | Curious. | [
"The mere presence of tension cannot yield energy. No net work is being done on the water or the balloon or the tether. If you release the balloon so it rises to the surface, then you could use the movement of the tether to do work (have it turn a crank, say)."
] | [
"I see. Thank you."
] | [
"This is essentially one of the ways you can harness tidal energy, but it would require a changing tension caused by the tide. "
] |
[
"Electron Spin Question"
] | [
false
] | When the spin of an electron is mentioned, does that mean that the electron is actually spinning or is it a mathematical property? | [
"So what is spin? It's a quantized intrinsic internal angular momentum. Let's go word by word from last to first. ",
"Momentum is a measure of motion, the tendency for an object to maintain said motion. ",
"Angular momentum is a measure of motion around some axis. ",
"Internal angular momentum is like the dis... | [
"It's not spinning in the classical way, like a top or a sphere or something. But you can measure a intrinsic spin angular momentum.",
"So, I wouldn't say that it's a mathematical property... more of a physical property that doesn't really have a good classical, everyday-experience analog."
] | [
"The idea of of a spinning electron comes from the idea that if you have a loop of wire carrying a current, the charges carrying the current are spinning around the loop. When carrying a current, a loop generates a magnetic field.",
"Similarly an electron generates its own magnetic field and thus in the early day... |
[
"Why do spinning hub caps appear to spin in the opposite direction?"
] | [
false
] | null | [
"This is called the ",
"wagon wheel illusion",
" and the wiki page is pretty good.",
"Edit: I should add that I am happy to answer additional or clarifying questions, but I would start on the wiki page."
] | [
"The rolling shutter effect is an effect of the camera, not an illusion (i.e. percieved effect). The rolling shutter effect happens because the shutter closes in finite time and in that time the subject may have had time to move."
] | [
"That's because it's not quite the whole story. See the ",
"top comment about the wagon-wheel effect",
", which is a perceptual phenomenon that is observed in real-life (i.e., not caused by the delivery medium, as this comment suggests) under continuous lighting conditions (i.e., not because of strobing). There... |
[
"Is there a distance at which the interaction between the gravity fields of two black holes would cause one another to effectively 'break open' and allow matter and energy stored within them to escape the system?"
] | [
false
] | null | [
"All space within the event horizon points towards the center (or is a closed loop back towards it)",
"There is no such thing as out. If two particles could talk to each other inside a black hole it would go like this: ",
"1: which way is out?",
"2: what is out?",
"1: Where am I going if I go this way?",
... | [
"The real reason why nothing could escape from a black hole, ever, is that space-time around a black hole is knotted into itself. If you start from inside a black hole, and plot all trajectories around you, all of them end up in the center of the hole. ALL OF THEM. Even if you move in a \"straight line\". There is ... | [
"No. If two black holes approach closely enough they'll simply merge. A singularity can't be broken apart by any level of gravitational attraction, because the gravity at the singularity is effectively infinite."
] |
[
"Why can't we create underwater breathing technology"
] | [
false
] | by mimicking what happens in fish' gills? Edit: I mean by "extracting dissolved oxygen from water to stay submersed indefinitely." (thanks ragnarokrudolph) | [
"We are endothermic and have a high metabolic requirement--one that is further stressed when we are submerged. Animals with gills, on the other hand, are almost exclusively poikilothermic and require much less oxygen. For us, the challenge is getting enough oxygen from the water to sustain our metabolism."
] | [
"Or really really large gills."
] | [
"Or really really large gills."
] |
[
"Do the centers of galaxies revolve around anything?"
] | [
false
] | [deleted] | [
"Galaxies don't really revolve around black holes in their center, because they have comparatively small masses. Instead, if you take spiral galaxies as example, the disk revolves around the galactic nucleus, while the stars of the disk influence each other gravitationally. You don't really have Keplerian orbits in... | [
"It's true that the accretion disks of heavy active black holes can emit so much light that it significantly slow down further infalling, but that happens much earlier before the black hole has half the mass of the disk and has not directly to do with the orbits of the disk matter. ",
"Whether a black hole is act... | [
"It's true that the accretion disks of heavy active black holes can emit so much light that it significantly slow down further infalling, but that happens much earlier before the black hole has half the mass of the disk and has not directly to do with the orbits of the disk matter. ",
"Whether a black hole is act... |
[
"Is all cell growth asexual reproduction?"
] | [
false
] | I know single-celled organisms can reproduce asexually, but when a cell in a multicellular organism divides is that considered asexual reproduction too? Bonus points for sources. | [
"Well, no.",
"\nAsexual reproduction refers to reproduction of an ",
" that involves no gametes.",
"\nReproducing a cell by mitosis within a multi-cellular organism isn't biological reproduction. ",
"I'm not sure which sort of sources you would want before you award the bonus points.",
"\n",
"But her... | [
"Asexual reproduction refers to reproduction of an organism that involves no gametes.",
"Isn't it more appropriate to state sexual reproduction requires exchange of genetic material? I've read somewhere that bacterial conjugation falls under the category of sexual reproduction while it doesn't deal with gametes."... | [
"Well, you're not ",
".",
"\nBut the bacterial conjugation is more like ",
" sexual reproduction.",
"\nIt's the exchange of genetic material, but there isn't a zygote produced from there. So it's not ",
" sexual reproduction; it's just kind of a grey area. ",
"(Edit: I think the bacterial conjugation... |
[
"Do different isotopes of elements have different proportions of allotropes?"
] | [
false
] | For example Sulfur 32 will have a majority of S8 allotropes because that's the most stable one. If neutron number changes the stability of the atom, will it also change the stability of the allotrope? (Say if I had a pure sample of Sulfur 34) | [
"There's three examples I know of. Naturally, these effects are pronounced for light elements where the additional neutrons are more proportionally significant. ",
"here",
"-Semiconductor guys studied isotope induced strain in single crystal silicon growth for wafers. Less strain equals fewer defects."
] | [
"Different allotropes are more of an expression of temperature, pressure and chemical environment and express chemical (think of it as inter atomic) stability rather than a result of nuclear stability."
] | [
"Indeed, allotropes are linked to the number of electrons in the atom, not the neutron number in the nucleus. \nOne example yet : a crystal of pure 241 Pu will be different from a crystal of 239Pu, because the latter decays via alpha emission with breaks apart the lattice structure, where as the 241Pu decays via be... |
[
"Are there any theories about, or is it likely that humans will eventually evolve into separate species?"
] | [
false
] | null | [
"So, the thing is that \"species\" are not really what you probably think they are. Most people have this concept of these neatly divided categories that things fall into because they have some intrinsic property. I.e. humans are humans because they have a certain quality of human-ness, chimpanzees all have some so... | [
"Until we develop space travel and colonize other planets/moons."
] | [
"Agreed entirely. Never say never, but probably not terribly likely.",
"A population being physically isolated on an extraterrestrial body, that's probably the most likely way we get a new species."
] |
[
"How can a guitar amplifier pick up radio waves and play them?"
] | [
false
] | [deleted] | [
"Radio signals are at a much higher frequency than humans can hear, so an essential aspect of this is that the amplifier also forms a ",
"diode detector",
" that happens to be tuned close by a radio station and therefore is capable of demodulating it.",
"My explanation of this would be that the transistors in... | [
"This isn't all that uncommon. It used to happen to me quite a lot when I had my old Marshall JMP out on tour. It has something to do with the broadcast being picked up in the internal wiring of the amplifier. Think of the wires inside as an antenna. After the antenna picks up the signal, the amp simply does it's j... | [
"To reduce this phenomena add tin foil to the back side of the amp. When I'm on tour and have some sort of RF interference this is what we do to cut down on it "
] |
[
"At what point will the our eyes stop recognizing higher definition videos?"
] | [
false
] | For the sake of clarity, lets say the video is on a 50 inch monitor. We are currently at 1080p right now and I truly dont know what anything higher would look like. | [
"It's a function of screen size and distance from the screen."
] | [
"Not exactly on the last statement.",
"24\" - mostly 1920x1080 and 1920x1200 ",
"30\" - 2560x1440 and 2560x1600",
"27\" - any of above, not sure which one is the most widespread for this size",
"As to OP's question - doubling the pixel density on monitor, f.e. having 3840x2400 24\" monitor would do wonders ... | [
"this video",
" is in 4k resolution, which is 4096 x 3072. ",
"this wiki page",
" touches on some potential applications for much higher resolutoins. Remember, both the screens and the source material would go up in resolution, and would blend in to our \"real life\" environment more and more as they did so."... |
[
"How do fiber optic cables work?"
] | [
false
] | So I was wondering how internet connections work and send information? So basically the coax cable (copper) used to be the main broadband medium, but companies like AT&T and Verizon have upgraded to fiber optics. How does light transfer information through a fiber optic cable? Does Comcast also have fiber optics? | [
"The data is usually encoded using intensity modulation...making the light brighter/dimmer, very rapidly. A light source, such as an LED, is rapidly modulated between bright and dim; the light travels down the fiber until it reaches its destination (or a repeater); a detector turns the light back into an electrica... | [
"You forget to mention the most important part. An optical fiber guides light down its axis by continually reflecting the light off the inside of the walls of its core via total internal reflection. Basically, by having a core with a higher index of refraction than that of the surrounding cladding layer, the light ... | [
"Yes, it is not only theoretically possible, it is a fundamental building block of almost every network in existence."
] |
[
"About the origin and nature of STDs"
] | [
false
] | I can't really narrow this question down to specific diseases, so please bear with me... If everyone on the planet currently infected with an STD be at viral or bacterial vanished, would the threat of gonorrhea, syph, hiv, etc. be gone as well? If not, how would one go about getting infected with them if there are no more infected partners to have sex with? I realize there is probably a big difference in regards to viruses and bacteria, so if anybody has an answer, please distinguish between the answers for the two. | [
"If everyone on the planet currently infected with an STD be at viral or bacterial vanished, would the threat of gonorrhea, syph, hiv, etc. be gone as well?",
"It's not an easy question to answer, and it depends on the nature of each individual STD, the mechanism of transfer, and where they originated. The one I... | [
"Evolution by natural selection. Viruses can evolve faster than almost any other life(?) form, due to their rapid reproduction/multiplication and error-prone DNA-related proteins that are responsible for copying the viruses genetic code."
] | [
"Ah, I see. By niche you mean the behavioural patterns in humans caused by there being no viruses. I thought you were suggesting that viruses would change their strategy because there's less \"competition\" in the STI world or something, which wouldn't make sense."
] |
[
"Why did the inner solar system's material accrete in to larger bodies rather than grind itself down to dust?"
] | [
false
] | Is this material still warm and 'tacky' enough to stick together? Or is there enough heat from impact that rocky material sticks together more than it breaks apart? Or do I have a total misconception about this process? | [
"There is, in fact, a wide gap in our understanding of how accretion works. It's very easy to stick molecule sized particles together, as they tend to stick electrostatically. It's also easy to get big particles to stick together due to gravity.",
"But when you get centimetre sized particles, they find it very ha... | [
"Water sticks together due its surface tension (electrostatics), not gravity.",
"At small scales the kinetic energy of particles is enough to make them not stick together by gravity. You only get gravity starting to make stuff 'clump' together when its large enough."
] | [
"Water sticks together due its surface tension (electrostatics), not gravity.",
"At small scales the kinetic energy of particles is enough to make them not stick together by gravity. You only get gravity starting to make stuff 'clump' together when its large enough."
] |
[
"Will there be an eventual limit to physical/athletic world records? It seems every year we run/pitch/jump/swim a mph/second faster/ foot higher. Will humans continue to become bigger stronger faster or will the body hit a point where it becomes physiologically impossible?"
] | [
false
] | null | [
"Please everyone this is not the place for speculation or answers that start with \"I'm not a scientist but. .. \" or \" I heard somewhere that. . . \". This is asking for certain biological and biomechanical factors that may limit mobility. All answers should be sourced and scientific. "
] | [
"It seems that we're within reach of a 2-hour marathon but won't be able to push much beyond that. ",
"http://news.discovery.com/adventure/extreme-sports/two-hour-marathon-111017.htm"
] | [
"Worth noting that the improvements have been getting smaller and smaller over time. There was almost as much improvement in marathon times in the fifteen years 1905-1920 as there has been 1920-present. ",
"Speeds in cycling have actually dropped in recent years, likely due to more effective anti-doping controls.... |
[
"If we can calculate/know the speed and direction of particles in the universe, couldn't we theoretically know the future? What is the counter argument for a deterministic view of the universe?"
] | [
false
] | This plays into whether we actually have any willpower (i.e. can actually make choices). I know one theory is that quantum events in our brains could be the source of our (potentially perceived) willpower, but to me it still seems possible for choice to remain just an illusion. I know this may count as a philosophy question as well, but I'd love to hear the science side first. | [
"We can't know both the speed and position of a particle with arbitrary accuracy. Heisenbergs uncertainty principle, which is one of the cornerstones of quantum mechanics, states that the more accurate our measurement of the position of a particle, the less accurate its speed measurement will be and vice versa.",
... | [
"Quantum mechanics makes it impossible to predict some outcomes. Depending on your how you interpret quantum mechanics, this could either be because (a) the universe is fundamentally non-deterministic, (b) it is deterministic but some \"hidden variables\" can't be measured, so we can't predict the outcomes, or (c) ... | [
"I think, even more important than Rannasha's point, is that the Heisenberg uncertainty principle doesn't just rely on ",
" of particles. It (at face value) is inherent to particles themselves; if a particle has a well-defined position, ",
", it cannot have a well-defined momentum. Among other paired particle c... |
[
"Why do things like glue, sticky notes and other adhesives like that become \"unsticky\" when it's cold?"
] | [
false
] | [deleted] | [
"Most glues conform to the shape of whatever they are bonding to. If there are microscopic ridges on a surface the glue would fill them This increases surface area for chemical bonding and attraction which is the primary way the glue sticks.",
"When its cold the glue can contract and it may not conform to the sur... | [
"Exactly what I was looking for, the chemistry of it. Thanks! "
] | [
"The glue gets harder, therefore less sticky. Similar to hardened glue"
] |
[
"My 3 yr old wants to know why the center of strawberries (the pith?) sometimes have empty space inside"
] | [
false
] | null | [
"The hollow centers are caused by the strawberries growing too fast from either too much water or too much fertilizer. AKA it's like a gap between your teeth that happens when they spread too fast, wild strawberries don't get gaps as much but farm grown ones that are given growth boosters tend to get a gap."
] | [
"It is caused by fast growth rate, hence why smaller ones don’t always have that hollow. Technically, all strawberries have it, because the strawberry fruit is actually a modified stem/flower, which is hollow. However, on smaller strawberries the hollow is too small to see because the more natural smaller strawberr... | [
"Ok. Let's be clear here. This makes it sound like slightly less fruity. What we are talking about is, properly ripened strawberries are a ruby, borderline translucent color throughout. Like a gem. Their flavor tastes like you extracted the strawberry essence from an entire box of grocery store strawberries and com... |
[
"Eridanus Supervoid, how is it that something that large can be completely empty?"
] | [
false
] | Also, is it possible for galaxies to move inside the supervoid and fill it out? | [
"It's not completely empty. There's still stuff there, just a lot less than the average of the universe. One principle of cosmology is the idea that at very large distances, the universe \"looks the same\" in any direction. Imagine you have a jar. You carefully lay a layer of blue marbles on the bottom, then a laye... | [
"a lot less being about ~20% less in this case, so there is still quite a lot of 'stuff' there"
] | [
"Thank you very much! That actually clears up a few questions I had :)"
] |
[
"Why is it so hard to remember our dreams but not our memories?"
] | [
false
] | null | [
"The basic idea is based on the number of neurological pathways that are activated. This can be observed in a few different ways.",
"\nFirst and foremost, most memories that we do tend to remember are associated with strong stimuli, whether that be a smell, taste, pleasure, pain, etc. This also explains why we ha... | [
"Sure, let me try to find one. This post was based on knowledge as a biology major currently pursuing a master's degree in exercise physiology."
] | [
"Sure, let me try to find one. This post was based on knowledge as a biology major currently pursuing a master's degree in exercise physiology."
] |
[
"Is the amount of virus material you recieve important in the course and severity of the disease?"
] | [
false
] | I can image with 1 virus particles you only infect one cell and it takes a while yo infect and thus kill other cells. in that tima the body can start working on an immune response. With recieving millions of virus particles those infect millions of cells that will die from reproducing the virus and also will be ahead of any immune response. Could this be explaining some of the health care and often younger cases dying? | [
"Yes. Like anything exponential, the initial amount and the rate of growth matter. So a small amount is better than a large amount. ",
"For a small amount of virus, the immune system also has more time to develop antibodies."
] | [
"Yeah using the word Chinese flu isn't really convincing me being knowledgeable. First of all it has nothing to do with influenza viruses. Second it did originate from China but the tragic epidemic unfolding in the US has shown China did eventually find a good policy in fighting the epidemic and much of the US gov... | [
"It's apparent that you are pushing the name for political reasons as no one in the scientific/health community names viruses after places. ",
"It's also apparent that you don't have any background in this topic and are here to push your narrative or stir the pot. This sub is for science not your ideology."
] |
[
"If sound travels best through solids, why is it harder to hear things when there is a wall between?"
] | [
false
] | [deleted] | [
"Sound travels nicely through the wall. It doesn't like the barrier between the wall and the air. It doesn't like to change from wall to air. Some is lost to reflection, etc.",
"Put your ear up to the wall, pressed against, and knock on the wall."
] | [
"To elaborate, you get reflections whenever there is a change in the stiffness (a.k.a. impedance). Some of the energy continues on, a small amount is lost to heat, and some is reflected back.",
"Similar effects happen if you are underwater. It is easy to hear sounds that came from underwater. You can hear the ... | [
"Sound travels best through homogeneous solids. Most walls, at least \"normal\" residential walls in the US (i.e. the only kind I know much about) are a mixture of wood studs, gypsum sheetrock, and possibly some additional form of insulation. The variation in consistency tends to cause lots of deflection in all dir... |
[
"Are viruses alive?"
] | [
false
] | null | [
"Viruses basically mark the border between what is clearly alive and clearly isn't. ",
"You will not be able to get a clear yes or no answer on this as arguments against viruses being alive are undermined by the accepted aliveness of symbiotic animals. ",
"Ex. A virus does not really independently have there ow... | [
"This issue is debated, and you won't find a single answer everyone agrees on. This is because the rules for what characteristics define life aren't agreed upon.",
"The more traditionally minded people (for lack of a better label) define life by meeting requirements like cellular structure, growth, metabolism, a... | [
"Humans can't survive without consuming other living things, so why should viruses be defined based on what they eat?"
] |
[
"Why do wounds inside the mouth heal more quickly than on other parts of the body? Does this mean spitting on a wound will quicken the healing process?"
] | [
false
] | null | [
"A few things factor into it:",
"The epithelium (outer layer of cells) inside the mouth has a much higher rate of turnover than the skin covering your body. That is, the cells at the surface die and slough off much quicker, and are replaced more rapidly by the dividing cells underneath. ",
"The epithelium ins... | [
"Last line:",
"Therefore, licking would be a way of wiping off pathogens, useful if clean water is not available to the animal or person."
] | [
"Although spitting may provide more bacteria, ",
" may actually help to remove other larger infective bodies.",
"From the Wikipedia:",
"A common belief is that saliva contained in the mouth has natural disinfectants, which leads people to believe it is beneficial to \"lick their wounds\". Researchers at the ... |
[
"How many arteries are there at the base of each finger?"
] | [
false
] | null | [
"Where exactly? The digital arteries coming from the palmar arch split up in that region."
] | [
"That should be roughly where they split up into two branches per finger."
] | [
"Let's say at the MCP joint, next to the long finger"
] |
[
"What is the benefit of breathing into a bag during hyperventilation?"
] | [
false
] | As I understand it (I'm an undergraduate bio major), hyperventilation occurs due to increased plasma CO2. Increasing your breathing rate causes more CO2 to be expelled. By breathing into a bag, you increase the amount of CO2 that you are breathing in, so your plasma CO2 increases. But isn't this exactly why you are hyperventilating in the first place? | [
"Increased plasma CO2 isn't the only cause for hyperventilation (anxiety induced being one other), in those cases the CO2 levels are normal and blowing it off causes an increase in blood pH. Recycling the air will get you to hold on to the CO2 and prevent the alkalosis.",
"Alkalotic pH can cause dizziness, visual... | [
"As a respiratory therapist, I support this comment."
] | [
"hyperventilation occurs due to increased plasma CO2",
"...and panic. Then the symtoms of respiratory alkalosis cause more panic and the whole thing spirals out of control. That's where the paper bag thing comes from."
] |
[
"What is different neurologically between sleep and a coma?"
] | [
false
] | I was taught that damage to the RAS causes comas. Is this the only cause? Do coma patients dream? Do they go through brain wave cycles similar to a sleeping human? | [
"They do not go through brainwave cycles anything like sleep. The EEG of patients who are comatose are varied but generally involve a high degree of non-reactive or only partially-reactive generalized arrhythmic slow activity. In some cases, they can show frontally-predominant monomorphic alpha or theta frequencies... | [
"What about medically induced coma? I've heard that when people are in a medically induced coma they were dreaming about stuff."
] | [
"I have personally supervised putting patients into medically-induced comas. Their EEG shows diffuse slowing or even suppression dependin on the depth. Patients with really bad traumatic brain injury are often put into a barbiturate coma to limit intracranial pressure. They push pentobarbital until the EEG shows a ... |
[
"We've been hearing about the soon-to-come male contraceptive pill for years and years now, why is it not on the market yet?"
] | [
false
] | null | [
"This is doubly true for anything that affects reproduction. That male contraceptive might be 99.9% effective, but what happens in that 0.1% where it fails? Does it have a teratogenic (ie, mutation causing) effect on the offspring? For that matter, does it have an effect (on users or potential offspring) when it... | [
"This is doubly true for anything that affects reproduction. That male contraceptive might be 99.9% effective, but what happens in that 0.1% where it fails? Does it have a teratogenic (ie, mutation causing) effect on the offspring? For that matter, does it have an effect (on users or potential offspring) when it... | [
"While this is certainly true, I'm pretty sure that there have in fact been specific announcements about upcoming male contraceptive pills."
] |
[
"Is there an upper limit to how fast a fluid can saturate paper through capillary action?"
] | [
false
] | I dropped a thin sheet of paper into water and noticed it was almost immediately saturated. Has anyone studied different fluids in different types of paper to see how quickly capillary action operates? | [
"Can't give you a number, the problem's too complicated. A Google Scholar search turned up a couple of review articles on the subject:",
"https://aip.scitation.org/doi/abs/10.1063/1.1722370",
"\n",
"https://journals.aps.org/pr/abstract/10.1103/PhysRev.17.273",
"but the overall physics is pretty straightfor... | [
"The washburn mothod, as outlined ",
"here",
", is widely used to measure surface energies of powdered materials.",
"As can be seen by the given definition in the link, the time taken for a given mass of liquid to uptake into a porous column of material is dependent on many properties of the system under stud... | [
"Who thought watching liquids absorb into powders could be so interesting."
] |
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