title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"Why can't diabetes type 2 be interpreted as a mechanism of action, instead of a malfunction?"
] | [
false
] | Good morning, and please forgive my poor understanding of metabolism. Why can't diabetes type 2 be interpreted as a defense condition, instead of a malfunction? Some chemical threshold has been reached and the immune system decides glucose is a threat and not a primary food, maybe the immune system is just wise. So it wants to prevent sugars from entering the cells. But if new environmental conditions ensue, and the person is starving, the insulin resistance drops, allowing again sugars to feed the cells. This doesn't look like a malfunction, maybe a questionable decision of the immune system, a defense condition. So the solution can't be administering more insulin since the body has enabled measures exactly to prevent insulin from delivering sugar. The solution would be just to stop eating sugars. What am I missing? Thanks in advance. | [
"There are multiple theories about type II diabetes. One says that fat is gumming up the works and preventing insulin from having the proper effect on glucose absorption. Another says that is about energy storage; the problem is that glycogen stores are full and that there is no good and quick energy sink for the e... | [
"What you're proposing would require a mechanism of gene regulation by second messengers responding to receptors or growth factors stimulated by the presence of carbohydrates, as far as I can imagine. This is much more complex than the concept of diabetes as a product of desensitising insulin receptors, or as an au... | [
"We consider it a malfunction because it's harmful. A questionable decision of the immune system that causes harm is considered a malfunction or disorder of the immune system in cases of allergies and autoimmune diseases, why would we not consider it as such for diabetes? Resistance or insensitivity to any other ho... |
[
"Are there environmental triggers that can \"turn on genes\" or is evolution purely survival of the fittest and random beneficial mutations?"
] | [
false
] | null | [
"Gene expression and evolution are different but related things. There are plenty of triggers, environmental and otherwise, that can turn on genes. Some of these changes can even affect future generations. For example, children of people who have experienced famine and low caloric intakes during childhood generall... | [
"There are various epigenetic mechanisms that can activate or deactivate genes based on environmental triggers, and these gene states can be inherited. But these genes have to evolve in the first place, and the epigenetic mechanisms that control them are themselves controlled by other genes."
] | [
"Yes, many things can change how much of a gene is being produced. For example if you get an infection, genes that produce antimicrobial proteins could be switched on. ",
"This is not in contradiction with evolution via survival of the fittest. For an example an animal that has a superior antimicrobial protein OR... |
[
"Does cork absorb any liquid?"
] | [
false
] | I know corks don't absorb water but I purchased a bottle of Crystal Head vodka with the intention of using it as a decanter for my scotch later. My question is if I put my scotch in there will the cork have residual flavor or even residual vodka that could potentially change the taste of my scotch? ( by the way this is a deal breaker because I'm a pretty serious scotch drinker and I don't want my high end stuff to change!) | [
"Corks can have surface cracks and open joints especially when left to expand or dry out and can allow leakage through the small gaps in its structure which leaves behind residue from drinks such as wine, which is why cork is generally put in a bottle under pressure.",
"You possibly will get some residual flavour... | [
"Bartender here. Never store corked spirits on their side--prolonged direct contact with the cork will impart a musty, \"corky\" taste to your liquor. (Much) Wine is stored cork-down in riddling racks prior to sale, and aficionados don't seem to mind the contact--but wine is much higher in sugar content and viscosi... | [
"Thankfully, more and more bottles are going to screw tops or artificial corks, but some things are sticking to tradition."
] |
[
"Why do some people snap better/louder with their non-dominant hand?"
] | [
false
] | Me and a few of my friends all noticed that we snap louder with our non-dominant hand. Why does that happen? Is it normal? | [
"The snapping sound is caused by your middle finger hitting your ring finger. If you haven't practiced this with your hand your middle finger will hit your palm and make a much quiter noise. However I don't know why you would only be able to do this with one hand and not the other."
] | [
"Is the reason for me not being able to snap with my non-dominant hand the difference in muscle strength?"
] | [
"Well you can snap without using a lot of muscle strength the trick is positioning your ring finger so your middle finger hits it on the way down. So it's definately not your muscle strength. "
] |
[
"Strange behavior in squirrels [X-post from r/biology]"
] | [
false
] | My office and I recently noticed some odd behavior from the squirrels outside our window. They started picking the leaves off the trees and dropping to the ground. We noticed it on a Thursday afternoon, and this morning on Monday, they are still at it. Leaves are getting all over the landscaping and the . Can someone please explain what they are doing? | [
"Depending on where you are and what species are endemic, I assume this is nesting behavior. Squirrels generally give birth one-two times a year - usually once in spring and maybe once again in late fall. They might be gathering leaves for a nest.",
"Edit: ",
"Actually, no, I think it really is leaf nest bui... | [
"Possibly these squirrels are young and don't have the hang of it yet, explaining the leaves on the ground instead of in the tree. Practice makes perfect, even in many animal behaviors."
] | [
"Correct me if I am wrong, but it looks like the squirrels are eating the Juniper berries; they do the same thing at my apartment complex in Missouri. They munch off a little branch and then scavange for the berries and ditch the leaves. ",
"Here",
" are a couple ",
"pictures",
" I took a while back.",
"O... |
[
"Why binary logic in computers?"
] | [
false
] | I am currently perusing a degree in computer engineering and I have yet to hear a solid explanation of why binary logic is used inside computers. After making several integrated circuits, I can see why it would be considered easier to work with binary, and how it is more cost efficient since the reduction that can be done with Boolean algebra, but what exactly is preventing us from having more than 2 stable forms of logic? I am not looking for the answer, "because it can either be on or off, 0v or 5v" since it is not true as far as my knowledge. In communication, a signal element can be assigned by voltage, such as 0v is 00, 2v is 01, 4v is 10 and 5v is 11. So in communication, we can have more than 2 states by using something as simple as a potentiometer. | [
"You can indeed work in bases that are not binary - ethernet seems to have 5 voltage levels and various buses easily work on logic that is ternary/tristate (pulled-up, pulled-down and floating) or quaternary if you want to make an obscure joke (pulled-up, pulled-down, floating, on fire). The fundamental issue is s... | [
"There are a lot of reasons but a big one is fault tolerance (which leads to a lot of the other advantages, such as simplicity of design, low cost, etc.)",
"The core component of digital logic is a transistor, which is basically an amplifier. Why would you use an amplifier as a switch? Well, for one it makes a ve... | [
"It's entirely possible to make computers which use ternary logic (see ",
"ternary computers",
"). "
] |
[
"Does stainless steel rust?"
] | [
false
] | [deleted] | [
"No it doesn't rust or corrode because although it is a ferrite it does not contain enough iron to be able to rust."
] | [
"nope"
] | [
"it will eventually corrode, but it takes a lot longer."
] |
[
"Are parasites microflora, microfauna, flora, or fauna? Does it vary for each species?"
] | [
false
] | I think I covered it? I will elaborate if necessary. | [
"\"Parasite\" is a role that one organism plays in relation to another. Organisms of all the kingdoms can play a parasitic role toward an organism of any kingdom as well. For example, ",
"a plant may be a parasite to other plants",
"; an animal may be parasitic toward a plant (sap-sucking insects for example) o... | [
"Well, first of all, \"flora\" and \"fauna\" are informal terms, roughly meaning \"plants\" and \"animals\". We talk about \"intestinal flora\", which are bacteria, but if we want to be precise, we'll call them by the ",
"kingdom",
" they're actually a part of, not \"flora\" or \"microflora\". ",
"I hadn't he... | [
"So in a sense our intestinal flora are tiny parasites? ",
"What about larger bacteria like say Thiomargarita namibiensis is that still considered flora?"
] |
[
"When it is quoted that we share '96% of our DNA' with chimpanzees or '99%' of our DNA with other humans, what exactly do they mean?"
] | [
false
] | I have a pretty good background in genetics, so feel free to be relatively complex. My question, more specifically, is are they talking about gene loci, individual nucleic acids or alleles. For example: If we have the same Gene, but my Allele is ATAT T and your allele is ATAT T do we share 5/6 (83%) same genetic material, 0% (because our alleles are different), or 100% because we have the same gene. Thanks! | [
"The percentage refers to the amount of nucleotide sequence divergence since a shared common ancestor. For the human and chimp genomes, the divergence is in Single Nucleotide Polymorphisms (one base substituted for another base, as in your example) is 1.23 % ",
"Source",
"When two ore more genomes are aligned, ... | [
"That image is a little different since it's a protein alignment, so it's looking at substitutions in the 20 amino acids, rather than the 4 bases of DNA. You were right in your original post that you simply take the number of columns where there is a difference and divide by the total length. However, this only acc... | [
"Ok. I think I overestimated my genetics background. However, I do have a few followup questions.",
"It seems that insertions and deletions would be where the most differences would happen. By removing those from the analysis, doesn't that severely overestimate the percentage overlap? ",
"Secondly, could yo... |
[
"How come when I take a shower/bathe in plus-100 degree water it is enjoyable, but not plus-100 weather?"
] | [
false
] | null | [
"Top comment is actually atrocious and does not explain anything at all.",
"Showers heat you up more than they cool you down, and the reason they feel good is because your personal body temperature is low enough that you enjoy the sensation. I assure you that if you spend enough time in a hot shower, you will sto... | [
"There are different ways heat can be transferred - conduction, convection, thermal radiation, and phase changing. Conduction heat transfer comes from coming into physical contact with a substance: here, that substance is water. Convection occurs when air blowing across the body results in heat transfer. One exa... | [
"There are different ways heat can be transferred - conduction, convection, thermal radiation, and phase changing. Conduction heat transfer comes from coming into physical contact with a substance: here, that substance is water. Convection occurs when air blowing across the body results in heat transfer. One exa... |
[
"Is this BBC video (concerning CO2 and the Greenhouse effect) slightly misguided?"
] | [
false
] | Firstly, I accept the theory of AGW and understand the basic mechanisms behind the Greenhouse effect. Here's the video that prompted my question: (Summary for those unable to view, the demonstrator has two lamps, two thermometers and two jars. One jar contains "Earth's Air" the other contains "Air + more CO2". She shines the light on each of them and the jar with CO2 is hotter after a certain period of time.) Now, obviously the greenhouse effect is playing a role. , CO2 has a lower specific heat capacity than air. As there is no mention of how much CO2 is in Jar 2 (and I'd be willing to bet it is a few orders of magnitude higher than 350 ppm) is there any way to attribute the warmer temperature solely to the Greenhouse effect and not just to CO2's lower specific heat capacity? Additionally, would a better experiment be heating the two jars to the same temperature and seeing which one cooled quicker? (Would the CO2 (despite its lower heat capacity) still cool slower...) (My hypothesis is that the slightly lower heat capacity does have an effect but not enough to change the outcome by it's lonesome. But I guess my point in writing all this is that I would like someone to reassure me?) Thank you for reading. :) | [
"I have my doubts about this demonstration, but instead of talking about those I'll try to address your questions about it.",
"First, what's being tested is the absorptivity of CO2. If you want to think in terms of specific heat, you have to compare Cv, not Cp. CO2 has a higher specific heat per mol than air. ... | [
"Watching the the demo again, I'm actually more impressed by it. I had four objections, three of which were not actually problems in the video: First, that the temperature increase was from the increase in pressure from the addition of CO2. But the canister was filled and then capped, so not a problem. Second, I ... | [
"Alright, thanks for taking the time to reply. My confusion was due in part to reading the comments on the video haha. Thank you for clearing this up for me.",
"The validity of the demonstration itself is partially why I ask though. Are your doubts because of the editting cuts made, not knowing the concentrations... |
[
"What is the most imminent event that would be fatal to the human race or Earth itself?"
] | [
false
] | [deleted] | [
"It would have to be a new viral disease."
] | [
"In my mind, a global nuclear war is number one, and a comet or astroid strike would be number two. "
] | [
"Be concerned about the environment. We are definitely going to run out of oil fairly soon, but there is also a big shortage of fresh water. And don't forget food. Global warming isn't helping any of these situations, of course. But what will happen when these things start to run out? War will determine who gets th... |
[
"How will my donated platelets be used?"
] | [
false
] | Just a few questions about my platelet donation. Most of the materials I could find referred only to whole blood donation. I had a scheduled donation of platelets at my local Red Cross donor center today. I am a 24 year-old male, 173cm, 70kg, type A+. I was told that I needed a platelet measurement of over 100 to donate at all, and the test on my blood had shown 355. I was hooked up to an apheresis machine for a hour and a half, and they took "three units" of platelets out, which more or less filled a large IV bag (maybe 500mL) and was approximately 1 trillion platelets total. I was told I would "save three lives" with my donation. What are the likely units on that platelet count? My count apparently isn't pathologically high, so how high would it have to be before it's be troublesome? What proportion of my platelets did I just donate, and how much more freely would I bleed if injured now? What sort of patients will receive my platelets (other than hemophiliacs, I guess)? Are they usually given via IV, like I conceive of whole blood transfusions? Is it likely to actually go to three different patients, or possibly to just one who really needs them? | [
"You actually wouldn't use platelets for hemophiliacs, since their defect is in Factor VIII of the clotting cascade. Platelet transfusions are important for people with thrombocytopenia (literally, platelet deficiency), which can be the result of pathologies like immune thrombopenic purpura, thrombotic thrombopeni... | [
"To elaborate on the range a little bit...it's my understanding that ~50k is an approximate threshold for immediate concern. 50-140k is a range where you should still be relatively careful, but you won't have major spontaneous issues.",
"Source: a few different doctors I've had for my fluctuating platelets over t... | [
"I used to work in a blood centre, issuing blood to hospitals (who then have their own internal blood banks).",
"The great thing about your donation is that someone who needs a lot of platelets could get them all from one donor. When they take platelets from whole blood there are less of them, so to make a single... |
[
"How much meaningful data (words) can the average person memorize and be able to perfectly recall at will indefinitely?"
] | [
false
] | Say I wanted to memorize a random book, or 5 books, or 20 books, but then I wanted to be able to perfectly recall, or orally recite, the information I have memorized at will. Is there an upper bounds to the amount of information the average person can memorize in this manner and keep it all straight within the context of each source? From my own experience with memorizing various long passages of text, I have to periodically "refresh" myself to maintain the integrity of what I have memorized. This is usually accomplished through simple recitation to myself from memory. I am just curious how much I can realistically memorize. | [
"It's limited by number of words to be memorized and number of words need to be recited in a day.",
"Let say you can memorize X words each day. But you also need to recite it at different time interval. Assume you need to recite a word in 1 day after, then 2 days after, then 4, 8, 16 up to 1024 days after (everyo... | [
"The phrasing of my question is probably not the best way to get the point across. For instance, I currently have approximately 15,000 words worth of information that I have memorized on a particular subject, from various sources and of varying lengths, that I can recall at will and recite with very little error. ... | [
"Hi, thx for clarify. maybe I try to estimate it using the formula above. Instead of using \"word\", maybe I called it item. An item can be a group of words / information/ a meaningful data point that one can handle at one time. Assume an average person can memorize 1 item in 6 minutes and recite each previously me... |
[
"What is the root cause of certain language speakers not being able to use certain sounds of other languages?"
] | [
false
] | The example that made me think of this: Asian language speakers often have problems with the 'R' sound from English. I understand that this can be overcome, but my question relates to the root cause of this inability to vocalize the sound in language without practice. Does this stem from those speakers not having trained their muscles or brain to create this sound (in essence, just needing practice to make them), or is it that they need to teach themselves how to about this sound being part of language. To simplify, can a Chinese language speaker make the 'R' sound while imitating a low dog growl but not in language because of how they think about language, or is the 'R' sound itself mechanically difficult to do? | [
"Not sure if this helps... But basically language acquisition works in young children by acquiring different phenomes. A child who grows up speaking Korean will learn different phenomes than a child who grows up speaking English. So I guess in a way it can have to do with practise -- you're just not exposed to the ... | [
"This.",
"My father was a linguist and he used to say you get the majority of an accent by trying to read other languages using your own memorized pronunciations - whether that's through symbols or repeating things you thought you heard."
] | [
"The answer has to do with what a phoneme is.",
"A phoneme is NOT a sound. A phoneme is actually a sort of \"potential\" sound, that can come out several different ways. The sounds in a language get grouped into phonemes. Errors often occur when someone's native language groups sounds into phonemes differently... |
[
"Why does it seem like cancer always attacks specific places, i.e. prostate, breast, colon, etc? Can you ever just have a random tumor like on your arm or something?"
] | [
false
] | null | [
"Cancer is the uncontrolled and unlimited division of cells which is why we cant stop aging because we would just be cancer balls",
"Actually, all of us have been cancer-free for 4 billion years of glorious cell division! And through our germ cells, most of us will continue forward for thousands or millions more ... | [
"I believe it has to do with cell division rates. Cancer is the uncontrolled and unlimited division of cells which is why we cant stop aging because we would just be cancer balls. Many cancer types are in places where the cells of that part of the body divide relativly quickly. More division means higher rates of m... | [
"You can have cancer in \"random places.\" Moles (those dark freckles you see on people's skin) are benign tumors. This is why you should get them checked if they are discolored, large, or unsymmetrical. Additionally, you can have a tumor, for example, a lipoma in adipose tissue. These are typically painless, but c... |
[
"How large could a rocky planet get?"
] | [
false
] | I know gas giants have a maximum size before they turn into a star, but do rocky planets have a maximum size before they destroy themselves or otherwise no longer act as a planet? | [
"It all really depends on your definition of a rocky planet. Or a rock for that matter. ",
"Athleticon93",
" is right for normally formed planets. Any planet getting really big as just a rocky planet is going to accrete lots of gas too and become a gas giant. But if we want to ",
" a really big rocky planet... | [
"First, I think you should distinguish between size and mass. There are some planets that are more massive without being much larger than Earth. For example the largest known planet is Kepler-10c, with a mass similar to Neptune, but it only has a radius 2.35x bigger than Earth.",
"You also must think about the di... | [
"What do you mean \"tear its atmosphere up?\""
] |
[
"What happens to oxygen (gasses in general) that get lost into the vacuum of space? Could (theoretically) we pump oxygen in space to create breathable pockets?"
] | [
false
] | null | [
"Gravity.",
"You need something to \"anchor\" that gas locally, and only gravity can do that. To have enough gravity, you need a big enough lump of something. That's basically a planet.",
"TLDR: You need a planet to keep the gas from wandering off into space. EDIT: Otherwise the gas cloud just keeps expanding."... | [
"The Shuttle, back when it was operational, was never too far from Earth. Gases from the vehicle would have remained bound to Earth by gravity, for the most part - doing orbits around Earth, most of those orbits would have decayed the usual way and bumped into atmosphere eventually.",
"(It's a bit tricky with gas... | [
"I'm fairly sure he is saying without a body of mass to attract the gas, the molecules go in their own directions. Imagine putting a few drops of red dye in the ocean. The molecules spread out, becoming more diffuse, and eventually are not detectable. The molecules are still in there, but your chances of finding on... |
[
"Why are the physical electromagnetic fields only the real part of E and B?"
] | [
false
] | says that the physical fields are only the real part of E and B, but this is not obvious to me. Since e = cos(x) + i sin(x) We get an imaginary part of the fields in the picture, but somehow these aren't actually a part of the fields, or how should i interpret i? | [
"Maxwell's equations are linear. So if ",
" and ",
" are solutions, so are their real and imaginary parts separately. Writing ",
" and ",
" in complex exponential form just makes the math easier since exponential are easier to deal with than sine and cosine individually."
] | [
"ok, the basic idea is this: you want to solve some ",
" linear differential equations (example: Maxwell's equations). By real, I mean the coefficients and differential operators in the equations are all real (they send real functions to real functions). In fact, let's be explicit, the system of eqts is something... | [
"Often you will see that electromagnetic equations contain some complex exponentials and then a \"+ c.c.\" for ",
" at the end of each line to make the whole expression real. Quite frequently people will just omit the \"+ c.c.\"."
] |
[
"Is hydraulic fracturing and shale gas really harmful to the environment? How would it compare to other energy sources including all steps from extraction to consumption?"
] | [
false
] | null | [
"I would link the EPA article but I'm on my phone. Extensive studies have tested the process and find it safe when the proper protocols are followed. "
] | [
"I would link the EPA article but I'm on my phone. Extensive studies have tested the process and find it safe when the proper protocols are followed. "
] | [
"It depends on a lot of factors. Fracing itself isn't dangerous, but if placed near a valuable groundwater source it is. Even then it depends very highly on the nature of the natural gas itself.",
"Its best to think of the problem from an environmental engineer's perspective - source, pathway, receptor. These ... |
[
"Say there was a pot of water that was heated to 150 degrees fahrenheit, and another pot's water temperature measured 50 degrees fahrenheit, if both were placed in an environment that held a steady 100 degree fahrenheit temperature, which would reach the 100 degrees faster?"
] | [
false
] | The pots are the same size, and the water amount is the same. The numbers are essentially arbitrary, and the unit of temperature isn't relevant. The question I'm trying to get across is - if two items were placed in an environment, and one item were just as much hotter than the other was cold, which one reach the base temperature of the environment first? Feel free to correct me on, inquire about, or even dismantle my inquiry; all I ask for is closure. Thank you, | [
"This is true if the only heat transfer is sensible heat (proportional to the temperature difference). However, if the pots were open to the air there is also the factor of latent heat of evaporation. The heat loss due to evaporation would be in addition to the heat loss due to temperature difference (delta-T) so t... | [
"Th mpemba effect has more to do with freezing temperatures as the molecules can align more easily into crystals at higher temperatures. For this situation, the simple model you use is what I'd consider. It's important to remember that the specific heat of a material is temperature dependant, and for water, like ma... | [
"The formula for change in temperature is (delta)T = Q / mc where Q is the amount of heat energy, m is mass, and c is specific heat. Judging by this equation, the pots should reach 100 degrees equally fast. But there is also the ",
"Mpemba effect",
" which could make the hotter water reach 100 quicker.",
"For... |
[
"Is there a better measure than expected value for bets that you can only make once?"
] | [
false
] | My girlfriend was badgering me to buy a bingo card in a $1000 bingo game once. The cards were $10. I told her we could do it if it looked like less than 100 people showed, because I figured the expected value of the card would be more than the cost under that condition. I realized that we only got to make this bet once, and I think that expected value is the average value the cards approach as you play the game an infinite number of times (right? it's been a while since I took stat). Assuming 98 other people showed up, despite expecting a profit, there was still a 98/99 chance that I'd simply be out $10. Is there another measure that's more appropriate for that situation? It would account for (1) you can only play the game once and (2) the potential profit? | [
"So, the distinction here is that expected value is the only statistic that matters if you're allowed to play the game an infinite number of times (i.e., you have an infinite bankroll or can go arbitrarily deep into debt). A related concept (for dealing with a finite bankroll, and either limited or unlimited plays... | [
"Ah, I see. Thanks.",
"Even if only 50 people showed up, there could easily be several hundred bingo cards in play, making the risk-vs-return question a moot point.",
"We didn't end up getting a card. Bingo's boring as hell."
] | [
"This doesn't directly address your questions, but expected value isn't the end all for decision making.",
"It is better to be concerned with expected utility rather than expected value. Money often has a diminishing return on utility. Thus, it is often the case that a loss of a dollar hurts you more than a gai... |
[
"What type of radiation is produced by the annihilation of interacting matter and antimatter particles?"
] | [
false
] | It is said that when an particle of matter and antimatter interact they annihilate releasing all of their energy. What is the frequency of the radiation energy that results? What determines this? | [
"Typically high energy photons aka gamma rays. If the collision is relatively low-energy then they photons will have the same energy as the mass of the particles, so for electron-positron collisions that's 511 keV or about 10",
" Hz."
] | [
"Not necessarily only two; larger numbers are possible (of course, they still have to obey conservation laws) but less common because the probabilities for such processes quickly decrease with the number of photons emitted.",
"There's even a case where the minimum amount of photons produced is actually 3, not 2: ... | [
"Specifically two, emitted at 180 degrees to each other if I'm not mistaken? "
] |
[
"Does the Sun have poles?"
] | [
false
] | Similar to either the two geographical or magnetic poles that Earth has? Do stars in general have poles? If the Sun does have poles, are the orbits of most planets roughly perpendicular to the Sun's polar axis? | [
"The sun rotates. So yeah the North and South pole are the points where the rotational axis coincides with the surface. Furthermore the sun has a magnetic field that has a significant dipole component. This dipole is aligned with the rotational axis, so the dipole poles are at the North and Southpole as well.",
"... | [
"You are probably thinking about permanent magnets, like neodymium magnets. However this does not apply to electromagnets. Remember that any moving charge, i.e. any electric current, creates a magnetic field.\nStellar magnetic fields of solar mass stars (of any star with a convective envelope really) are created in... | [
"What allows the sun to have a magnetic pole? I thought that materials lose their magnetic properties as they get hot? "
] |
[
"Vasoactive drugs like Norepinephrine, Epinephrine, Vasopressin work differently on the heart. What are their actions on the heart and how is it determined which order these drugs are given?"
] | [
false
] | null | [
"Another thing to consider is the sensitivity of these compounds for specific receptors. The heart contains predominantly beta-1 adrenergic receptors, while the vasculature contains both beta-2 and alpha-1 receptors, that vasodilate and vasoconstrict when activated, respectively. Norepinephrine is much more selecti... | [
"Sorry if this is late: Your question is very vague, so i'll try to answer best as I can. ",
"Norepinephrine is a neurotransmitter, such that it is only released by neurons and is not a hormone (unlike epinephrine and vasopressin, meaning it is not released into the blood stream). On the heart, NE acts to chronot... | [
"NE is released into the bloodstream by the adrenal medulla, in addition to being a neurotransmitter."
] |
[
"Does learning a language continuously get harder as one ages, or is there an age where the difficulty plateaus?"
] | [
false
] | null | [
"Finally an opportunity to give something back to the mighty jorgfeldkt!",
"Here's",
" an article (containing two reports) that pretty much supports my personal experience as a trilingual+ person, but I am certainly a layman here. (If you're curious, the languages are Norwegian, English, French, I speak some Se... | [
"It's not that it doesn't work, it will eventually. The US government uses Rosetta Stone a lot, for reasons passing understanding, and while I don't expect them to get the best, they wouldn't use it if it did nothing. So it will teach you a new language, just not in a way that makes good use of your time.",
"It's... | [
"In addition to the poop ctolsen said, there are fundamental things different from how adults learn and how babies learn that put us apart in language. For a real simple example, take trying to teach someone the first consonant sound in \"this.\" Turns out not a lot of languages have this sound so a lot of people h... |
[
"What happend to the Enigma Machine?"
] | [
false
] | In school we are currently doing a short unit on Turing and how he decrypted the Enigma machine. I was wondering if there was anything which improved upon the designs of the Enigma machine? Or something that became the "spiritual" child of the enigma machine during the korean/Vietnam time period in order for the super powers to protect their secret messages/orders? I've tried to do some searching myselfand have found nothing. My history teacher is drawing a blank as well. So I was wondering if any of you knew anything? | [
"It's interesting to note that the Enigma was technically obsolete by the start of WWII and should not have been used by the German military. A big problem with the Engima and other devices like it is that it does a piss poor job of increasing entropy (i.e. randomness) of the cipher text. What this means is that ... | [
"The algorithms that are used nowadays are so sophisticated they couldn't run on a electromechanical machine like that, they use super computers. ",
"The last part of that isn't true. Encryption algorithms run on your smart phone. Breaking encryption is a much, much, much harder problem than performing the encr... | [
"Are you asking about the Enigma machines (of which there were 100's or 1000's used by the Germans) themselves? Wikipedia says this:",
"An estimated 100,000 Enigma machines were constructed. After the end of World War II, the Allies sold captured Enigma machines, still widely considered secure, to developing coun... |
[
"How do rocks naturally get knto the position of balancing on another rock?"
] | [
false
] | Like in finladn there's a 500 tonne rock balancing on top of another one for ages, its so heavy that there is no way someone moved it there, smaller one's are also in Poland and all over europe, just how do they get there? | [
"Depending on the examples in question, there's going to be a few different options, I'll discuss two common/possible ones here.",
"(1) For ",
", or as their often referred to in a paleoseismic context ",
" or just PBRs, these often form ",
". As described in a variety of publications (e.g., ",
"Bell et a... | [
"Wow, thank you, this was educational"
] | [
"If you want to see a lot of big rocks balanced on small rocks, in the most amazing setting you can imagine, head to Palm Springs CA and the nearby Joshua Tree National Park."
] |
[
"Why do we have earlobes? What purpose do they serve?"
] | [
false
] | [deleted] | [
"Here is an excerpt on Pinna from ",
"a lecture on Perception",
":",
"With the ears, there are at least two aspects of the sound that are different between the two ears as the function of sound sources' position.",
"inter-aural amplitude and timing differences - Differences in when the sound arrives and how... | [
"I've just done some quick googling, and got to this ",
"http://en.wikipedia.org/wiki/Pinna_(anatomy)",
"The whole outside of your ear is used to increase the amount of sound you can pick up, and that would include the lobe too. I have no idea whether or not the Lobe would really be detrimental to \"catching\" ... | [
"So if I held my Pinna and closed my eyes, I would have problems determining wheter a sound source is in front or behind me?"
] |
[
"How does a wireless signal get converted into binary?"
] | [
false
] | When you send a wireless signal from, for instance, a remote control to a tv, how does the tv interpret these signals and convert them into binary? Does the remote control just turn off to represent a 0 and on to represent a 1 or is the process more complex? | [
"The whole process a signal takes is a little different for analog and digital, so this will be primarily from the digital perspective.",
"The process begins by taking any source (sound file, video file, Web page, etc.) and representing it as a binary string. From there we usually first compress the string. How w... | [
"Remote controls for a TV are a bit more complex than the process you've mentioned (0 = off, 1 = on), but not much.",
"A common IR remote protocol is the so-called RC5 protocol. This protocol always sends a pair of signals to encode a single bit. A \"0\" is represented by the signal \"on-off\", whereas a \"1\" is... | [
"Thanks for the explanation! Especially on QAM. I'll look into that."
] |
[
"Is there a such thing as a perfect laser? Do all lasers eventually lose their focus over a long distance? Does the strength of a laser affect its accuracy?"
] | [
false
] | null | [
"People think of lasers as a perfectly cylindrical beam of light. That's only an approximation which does not exist in reality.",
"A laser beam, like any other light beam, is an electromagnetic wave. What makes it approximately cylindrical near the source is the fact that it's emitted as a coherent wave from a ci... | [
"Diffraction limited angular resolution",
"A red laser which starts at 3 mm has a minimum beam width of 100 arcseconds or 0.00048, meaning that at 1 km it has already spread to 48 cm. And this is assuming that the laser manufacturers did an absolutely perfect job with everything (they didn't)."
] | [
"Yes, but the divergence angle can be reduced by increasing the width of the beam, e.g., by shining it through a wide aperture telescope. A wider beam from the transmitter gives a narrower beam at the receiver and vice versa, provided that we have a collimated beam at the transmitter."
] |
[
"Is there a way for humans to gather information faster than reading?"
] | [
false
] | With the advent of the internet and smartphones, we have access to an enormous amount of information. But with our fast-paced fun-filled lives, we don't seem to have the time to research everything we'd like to learn about. Has anyone heard of a device or technology that uses a different sense, outside of sight and sounds, that allows a faster 'download' of information? | [
"Interesting question.. But I guess it depends on what you define \"learning\" as. Reading is simply using our sense of vision to recognize symbols and lines on a page, and our brain applies meaning to them.",
"You could say that we \"learn\" not to touch a hot stove because after touching it once, our sense of t... | [
"Sight allows for amazingly fast transfer of information if it's formatted correctly. Two-dimensional data is particularly easy to transfer in the form of graphs and charts. However, procedural knowledge is limited in transfer rate (actually limited to a speed much slower than typical reading speed) due to the incr... | [
"You might be interested in \"Decoded Neurofeedback\". Straight upfront; I don't know much about this field, nor I don't know how much headway has been being made in it recently.",
"That said, the basic premise is to upload skills directly into an individual's visual cortex using FRMI. As I understand it, if th... |
[
"Why don't humans, unlike other animals, produce Vitamin C even though it is necessary for our health?"
] | [
false
] | Currently sick and drinking Emergen-C. It got me thinking that if Vitamin C is integral to our well being why are we one of the only animals, besides guinea pigs and other apes, that don't produce it internally? | [
"Because we ate so much fruit historically that losing the ability to create vitamin C didn't cause us any harm. If you go through the human genome, you can still see the mutated remnants of the same vitamin C producing gene that still works in our relatives.",
"Of course, it's probably a disadvantage nowadays w... | [
"it's an acid and it's essential but it's not an amine which is where \"vitamin\" comes from.",
"It's a fun and totally useless fact."
] | [
"Modern humans don't manufacture vitamin C because we lost that ability much earlier in our evolutionary line, and have not regained that mutation since.",
"Humans, apes, and monkeys all share this deficiency as a heirloom from a common ancestor that developed a mutation that had fundamentally no effect on their ... |
[
"Why is it hard to pull a magnet off a metal surface but so effortless to slide it across the surface?"
] | [
false
] | Playing with my name tag and it got stuck to my pen holder. I wasn’t able to pull it off but it easily slid off. I don’t get why a magnet doesn’t pull back to the original position when sliding. | [
"It's the same reason why a couch is difficult to lift but easy to slide across the floor: trying to lift the object means opposing its full mass, but sliding it only requires opposing its \"mass x coefficient of friction\", which depending on the materials involved can be tiny, which will result in far less force ... | [
"The magnetic field creates forces that oppose the forces from your hand lifting the magnet up. But there's nothing opposing motion side-to-side besides friction. Friction along smooth surfaces can be modeled by taking the normal force of the object (in this case, the weight of the magnet plus magnetic forces pulli... | [
"Striction is not deliberately factored in since it behaves differently (ex: a piece of tape can pick an object up, but friction between two things cannot do that), but there is a bit of handwaving with the standard friction formula since it is partially determined by experiment so there is probably a bit of it fac... |
[
"Why is the aurora borealis phenomenon typically only visible at higher latitudes?"
] | [
false
] | With recent solar activity I had read an article that showed this phenomenon visible farther south than normally seen and it got me wondering. | [
"That is where Earth's magnetic field is the ",
". The auroras are caused by solar winds being deflected strongly and ionizing parts of the upper atmosphere."
] | [
"There are actually two auroras- the aurora borealis is in the northern hemisphere and aurora australis is in the southern hemisphere.",
"In general, the lights can only be seen within around 10 degrees of earth's magnetic poles. This is because the auroras are caused by charged particles that originate from sol... | [
"Thanks!"
] |
[
"Why is the salinity of the worlds oceans not constant?"
] | [
false
] | null | [
"simple answer is saline water is denser than fresh water, and the cycle of evaporation to precipitation generates fresh water, which eventually ends up back into the ocean and due to density, it floats on top.",
"another cycle happens near the poles where cold saline water freezes and also differentiates freshwa... | [
"Surface waters in ocean regions for which evaporation exceeds precipitation tend to increase salinity (the middle of the subtropical gyres, for example). Regions for which average precipitation exceeds evaporation become fresher (North Pacific ocean). Ocean currents slowly mix the salty and fresh regions so that ... | [
"You already have an answer to your specific question, so I’ll just add that even though salinity does vary in the oceans, causing water masses to have different densities (salinity and temperature control seawater density) so that they do not easily mix, there is still something about salinity which remains remark... |
[
"Most sites say cats become malnutritioned if fed only meat and never any \"cat food\". Is this a marketing scam, or how would wild cats have been able to survive in nature?"
] | [
false
] | Been reading about how one would provide a full nutritious plate to a cat without using super processed "cat food"s, and this always strikes me as weird (seeing as cats are obligate carnivores). | [
"Wild cats survive by eating animals. Not just what we call \"meat\" (muscle tissue), but organs, bones, entrails, and the contents of the digestive systems of those animals (mostly plant matter.) That gets them a lot more varied nutrition than just muscle tissue (which they do need to be healthy.)"
] | [
"First, wild and feral animals don’t necessarily get the best nutrition. Feral cats sometimes only live a few years and succumb to diet/related disease. ",
"Second, it’s a misconception that they only eat meat. Obligate carnivore meant it must eat meat, not that it excludes other nutrient sources. The stomach c... | [
"Cats in nature don't eat only meat, if by 'meat' you mean muscle. Cats eat almost all of whatever they catch, which includes bone, marrow, liver, brains, lungs, and other organs. Eating muscle alone would lead to malnutrition."
] |
[
"Are quantum dot solar cells all hype?"
] | [
false
] | There seems to be a lot of hype regarding nanocrystals/ quantum dots for solar cells. Could someone explain something to me? A lot of the cool effects like tunable bandgap and strong absorption come from the quantum confinement. Quantum confinement implies that the electrons and holes are confined to a very small space. This seems completely opposite of what you'd want to do for a solar cell, which is to move the generated electrons and hole out to contacts. If you enable movement of electrons and holes, you destroy the quantum confinement. If there's all of this hype out there for making super efficient and cheap solar cells using quantum dots, I'm obviously missing something. What am I missing? TLDR: Quantum dots confine holes and electrons to a very small space. Solar cells move electrons and holes. How do quantum dot solar cells make sense? Cross posted from : | [
"In the ground state, they are confined. In the electronic excited state (if they work), the electrons and holes should be mobile. This relies on there being a suitable donor or acceptor nearby to keep the process going."
] | [
"\"In the ground state, they are confined. In the electronic excited state (if they work), the electrons and holes should be mobile.\" ",
"I completely agree. How would you excite those states? Thermalization (relaxation to the ground state by phonons) happens very quickly. I would think you'd have to apply a... | [
"I'd think that you would have your quantum dots on a substrate that would allow for electron transfer. If they're really worth using, a monolayer of dots should be all that you need. ",
"I'm not sure what you mean by \"exciting\" the excited states. The challenge in all photovoltaics has been harnessing the e... |
[
"Can being crushed by magnetic field?"
] | [
false
] | Saw this youtube and I'd really like to know the physics behind it. | [
"This effect can be replicated at home (less impressively but more safely) with a fridge magnet and a sheet of aluminum. Just set the aluminum at an angle and let the magnet slide down it. You will notice that the magnet slides more slowly than if you replaced the aluminum with wood. ",
"Here's what is happeni... | [
"You can also drop a cylindrical magnet through a copper pipe. It will fall very slowly."
] | [
"Cf quartershrinkers. "
] |
[
"Are there any studies on the long term health effects of very light smoking (1 or 2 cigarettes per day)?"
] | [
false
] | I've been a light smoker for about 10 years. I keep it around 1 or 2 per day and usually stop completely during the winter since I don't smoke indoors and it gets too cold outside where I live! I was looking at studies on light smokers but it's usually defined as way more than 1-2 per day. Sometimes it's less than 20, or less than 10. That's not my definition of light smoking. | [
"Cancer is believed to be a ",
"stochastic",
" effect. This means that the probability of getting a disease is proportional to your exposure to cigarette smoke. So a light smoker would have a lower chance of getting cancer but not a zero chance, ie there is no safe amount of tobacco smoke that won't give you ca... | [
"I found a Norwegian study with n>40,000:",
"\"Results: Adjusted relative risk (95% confidence interval) in smokers of 1–4 cigarettes per day, with never smokers as reference, of dying from ischaemic heart disease was 2.74 (2.07 to 3.61) in men and 2.94 (1.75 to 4.95) in women. The corresponding figures for all c... | [
"You always have a non-zero chance of getting cancer. But what I think you meant was a lower but non zero increase in your chance to get cancer."
] |
[
"Why (in technical terms) the video cards are the best for Parallel Computing?"
] | [
false
] | What the GPU's and memorys from Video cards have, that make them good for that? | [
"Modern GPUs are best described as vector processors with specialized instructions for graphics rendering. A vector processor is very much like a CPU (actually, it ",
" a type of CPU in some architectures), but it is designed to perform the same instructions (or sets of instructions) on multiple pieces of data."... | [
"Games use the GPU for more than graphics, but not much more. There are GPU implementations of integration engines for physics engines, for instance.",
"A good rule of thumb for determining if a vector processor is a good choice for an operation is, does this operation need to wait for any other operation? If s... | [
"Thank you for you backup!",
"But, may i ask one more thing =p? You said that the GPUs good for operations that are repeated many times, but they arent good for complex operations, and i can presume that CPU'S are good for that.",
"May question is? In a game for example, the GPUS only process grafhics, because ... |
[
"Why do men tend to only go bald on the top of their head and not on the back or sides?"
] | [
false
] | null | [
"Citation? This is all insanity. ",
"Male baldness is thought to be predominantly caused by hormones called androgens. The hair follicles on the top of the head have more androgen receptors.",
"The hormonal cause of male pattern baldness is demonstrated through the fact that people with hormonal deficiencies or... | [
"Citation? This is all insanity. ",
"Male baldness is thought to be predominantly caused by hormones called androgens. The hair follicles on the top of the head have more androgen receptors.",
"The hormonal cause of male pattern baldness is demonstrated through the fact that people with hormonal deficiencies or... | [
"What in the fuck did I just read? I actually can't stop laughing this is hilarious. "
] |
[
"Does the use of LSD cause anxiety, OCD, or other neurotic tendencies latter in life? What about other \"entertainment\" drugs kids use - are there any studies that tie them to psychological problems later in life?"
] | [
false
] | After seeing the question about Marijuana being linked to schizophrenia, I wanted to ask if there is any scientific research linking LSD to neurotic tendencies when people get older. What about other recreational drugs like speed, etc? Anecdotally, most of my childhood friends who were acid-freaks have now have major OCD or anxiety issues. Most have to take Ambian or something like that to calm them down enough to function. | [
"There is very little formal research into the long term effects of LSD.",
"The work that was done while it was legal suggests that it has significant potential as a tool in psycho-therapy. That it can be a significant aid in overcoming addictions. And that it is pretty useless at creating drug fuelled super-sold... | [
"My understanding is that there are no physical effects from LSD that can cause any type of permanent brain damage. From a chemical point of view LSD is extremely safe.",
"The hallucinogenic LSD experience can be profound. Intense.",
"In the same way that any profound, intense experience can be life changing - ... | [
"My understanding is that there are no physical effects from LSD that can cause any type of permanent brain damage. From a chemical point of view LSD is extremely safe.",
"The hallucinogenic LSD experience can be profound. Intense.",
"In the same way that any profound, intense experience can be life changing - ... |
[
"I Can't Figure Out Climate Change"
] | [
false
] | Ok, first of all, no, I am not some right wing lunatic that thinks global warming/climate change is a plot by the filthy liberals to take my guns or something. I just have a few questions that I'd be too embarrassed to ask to real life friends. 1.) I 100% agree that both the world is getting warmer and that the carbon dioxide level in the air is going up. Humans obviously have caused this increase in carbon dioxide. My question is: How do we know this increase in carbon dioxide is the cause of the rise in temperature? Is the answer just "greenhouse effect" and that's it? Do we know that holds on a huge scale, like, well, the earth? 2.) From the statistics I have taken in both high school and college, it has been repeatedly slammed into my head that extrapolating data/models into the future is an very inexact science, at best. How do we know the current trends in temperature will continue? Carbon dioxide will continue to increase, for obvious reasons, but if it is causing the warming, how do we know it won't hit diminishing returns? 3.) I keep hearing that the line of no return for doomsday temperature increase is six degrees Celsius. Could someone explain why that would be so damaging to the health of the planet/humanity? Any answers would be appreciated. Sorry if they're dumb questions, I know this is an old-ish topic. | [
"RealClimate.org",
" and ",
"SkepticalScience.com",
" have well researched answers to most climate questions so I would mostly just point to places at those sites.",
"The planet is not warming up uniformly. For me, the most compelling evidence is the many detailed signatures of global warming predicted by ... | [
"We can measure absorption of infrared radiation by carbon dioxide. We can put it in a tube, shine an IR light in one end, and measure the intensity of the light making it to the other end. Some will have been absorbed and re-emitted back towards the light source. I can't think of a reason why these properties woul... | [
"My question is: How do we know this increase in carbon dioxide is the cause of the rise in temperature?",
"Carbon dioxide gas absorbs infrared radiation. So do other gases- water vapor, for example. But anthropogenic production of carbon dioxide has demonstrably increased ",
"the concentration of atmospheric c... |
[
"How can we be sure of the precision and accuracy of modern measurement tools?"
] | [
false
] | Suppose I have defined a 'redditmeter' [rm] in some acceptable way (that is - I can always know that this 'thing' that I measure is indeed rm units in size). After a few months, a new way was invented to measure 0.5rm, so on so forth - we get to the smallest scales. I logically conclude that this process is a very crude way of what happened in the way we humans measure things like length, weight etc. But how can we be sure that the scales we measure today are actually accurate? if we can measure 0.5rm with 99% accuracy, then measuring 0.25rm might have even less accuracy, going all the way to 1*10 rm. How can we know that our measurement tools are actually acceptably precise? Or to put it in another words - How do we check our most modern and precise measurement tools? Thank you for your current attempts of answering, but my question wasn't how can we be sure that a kilogram is a kilogram. To clarify furthermore - How can we be sure that the most modern measurement device actually measures with a good enough precision and not with it's measurement fault being 50% of accuracy (50% of times or 50% of given value). | [
"Currently, most units of measurements are derived from fundamental physical properties. For example, the meter is defined as the distance that light travels in a vacuum in 1/299792458 seconds. There is no ambiguity or inaccuracy in this definition, because it's defined relative to an unchanging constant of the uni... | [
"The second is the duration of 9,192 631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom",
"So, you have an exact definition there. This allows derived units to be exact as well. "
] | [
"National time standards like NIST and the Naval Observatory use dozens of clocks and statistical methods to arrive at the best \"average\". The difference between the standards is quite small and their stability meets our current needs. "
] |
[
"How does a CPU decide which instructions use which RAM addresses? (In terms of digital logic)"
] | [
false
] | I've spent a small amount learning about digital logic to further my understanding of computers but 1 thing I can't really understand is how the computer decides that RAM address X will be allocated for program Y and then after processing other instructions can come back to address X and can still associate it with program Y. | [
"It doesn't.",
"When the CPU powers on it's hardcoded to run some code from somewhere. x86 for instance, will start executing whatever happens to be at address FFFF:0000, which is where the BIOS code is located. The BIOS initializes some hardware and tries to find a disk to boot from, loads the boot sector from t... | [
"This question touches on many aspects of modern computing systems. I'll try to address a few:",
"The addresses used by each instruction are either fixed at a constant value, or drawn from another location that has the desired value. For example, one instruction might say \"write contents of register A to the add... | [
"TLDR: What instruction goes where, and how it gets there, is a concern of software, not hardware.",
"Memory allocation and separate programs is more of an OS-level thing than a hardware-level thing.",
"The CPU pretty much has exactly one instruction address hard coded inside it, called the ",
". This addre... |
[
"Does scratching a (non-contagious) rash, such as poison oak, help or hinder healing?"
] | [
false
] | I recently came in contact with poison oak and it itches to high heaven and scratching it is almost the greatest feeling ever before it starts itching again. I understand that itching helps bring more blood to the area. Aside from itching so much that you break the skin and cause more damage, does scratching speed up the recovery? | [
"The rash caused by poison oak is due to a T cell mediated reaction to the toxin urushiol. If you were recently exposed, scratching would make it worse because you are more likely to spread the toxin to other parts of your body. Once the toxin is removed and you're left with the rash, scratching wouldn't do anythin... | [
"More blood to the area is bad. The poison oak sap soaks into your skin and shreds your blood vessels causing them to leak plasma. Scratching won't spread the rash but will cause more/bigger pustules. ",
"It take 7-14 days to go away. Cold-packs have been shown to speed recovery in some individuals. ",
"Your... | [
"I'm mostly guessing, but maybe it helps against something like a bee sting. If the stinger is still stuck, it will pump more and more poison into you, Scratching might dislodge it."
] |
[
"Do bugs have muscle tissue?"
] | [
false
] | How do insects or arachnids move their legs? | [
"Yes, they do have muscle tissues. However, their muscles are slightly different from mammals. Insect muscles do not need to be constantly oxygenated to function. They mostly just need sugar that comes from the hemolymph (insect blood), and can get away with less oxygen. In the laboratory, we can perfuse insect mus... | [
"You're on the right track about \"much bigger scale\". There are good reasons why our muscles need to be constantly oxygenated. Our muscle size is gigantic comparing with insects. The strength we can muster from our muscles is much larger, so our muscles need to obtain much more energy than insects muscles to func... | [
"It's kind of a dumb question, but what do you think would happen if we did some DNA engineering and placed insects' genes for muscle tissues in our DNA? It seems advantageous that our new muscle would need much less oxygen. But then again, I suppose insect muscles wouldn't work in a much bigger scale."
] |
[
"Can a bee or ant colony survive without a queen?"
] | [
true
] | [deleted] | [
"Only queens reproduce. However, the death of a queen is not the death of a colony, necessarily: ",
"National Geographic",
"If the queen dies, workers will create a new queen by feeding one of the worker females a special diet of a food called \"royal jelly.\" This elixir enables the worker to develop into a f... | [
"How do they choose the worker? Is it random? Do they chose only one or do they feed them all jelly till one is ready and then she executes the others, like african bees or Queen Elizabeth I?"
] | [
"It really depends on the which specific ant or bee species you are asking about. Many species are monogynous, meaning they only have one queen. For some of these species, if the queen dies, thats it. They will not produce or acquire a new queen. The colony will eventually die out. For some species, they can a... |
[
"If you could survive the molten hot lava of a valcano, if you went in it and went down would you reach the centre of the earth."
] | [
false
] | [deleted] | [
"The simple answer is a big no.",
"The detailed answer is that volcanoes erupt when a batch of magma within a chamber int eh crust overpressurizes. That can be due to a number of factors, but at best the continuous fluid magma will not penetrate more than a few kilometers into the crust. Once you're below the hig... | [
"Have we found anyway to stop a volcano or even make one dormant? Whether it be earily stages that we catch it or days before it erupts?"
] | [
"The enrgy involved in an eruption is orders of magnitude greater than we can do anything about with present technology. The energy ofa volcano is due to the great depth at which the magma is generated, and physical buoyancy, coupled with expansion and depressurisation effects. I't simply not something we have the... |
[
"Is it possible for 2 total strangers be more genetically similar than 2 siblings?"
] | [
false
] | I recently came across a photo collection of strangers who look almost identical, which left me with 2 questions: When 2 people look alike does that mean they are genetically similar, or is it just an anomaly that they ended up looking the same? Is it possible for 2 total strangers (regardless of looks) to be more genetically similar than 2 siblings or relatives? If so, how often does this occur in nature? If not, why not? Thanks! :) EDIT: I was in no way implying any specific definition of "sibling" versus "stranger", nor referring to separated twins (still genetic siblings and social strangers), nor implying that adopted siblings aren't truly siblings. Sorry for any unintentional offense. | [
"Possible? Certainly. Probable? Highly unlikely. They ",
" have to be in the same family lineage, though the odds would still be astronomical even then. ",
"Basically, imagine a parent has two kids. With a crazy toss of the dice, one parent (say, dad) passes one half of his genes to one child, and the ",
... | [
"They ",
" have to be in the same family lineage, though the odds would still be astronomical even then. ",
"Wait... this kinda deflates the original proposition by narrowly redefining things, but also muddies it by undefining things.",
"Every living thing is to some extent or another in the same family linea... | [
"Good answer, but FYI, 3 billion is the haploid genome number, so the estimate should actually be 4"
] |
[
"How do most antidepressant drugs cause weight gain?"
] | [
false
] | Do they make us eat more? Does it change the metabolism? Can they be used in anorexia? | [
"The mechanism of weight gain by antidepressants is still under study, but can be explained by the antagonism effect on the histamine-1 (H1) and serotonin 5-HT2C receptors, and the disruption of leptin signaling. The evidence is strongest with histamine-1 antagonism. ",
"Histamine-1 Receptor:\nBlockage of this re... | [
"Kinetics, transport, and metabolism of macromolecules are altered. If the drug or toxicant changes the pathway so that more “stuff” goes into the fat cell rather than going into the liver or muscle to be broken down and used, it will promote weight gain over the long run.",
"As an additional example, say we tran... | [
"Kinetics, transport, and metabolism of macromolecules are altered. If the drug or toxicant changes the pathway so that more “stuff” goes into the fat cell rather than going into the liver or muscle to be broken down and used, it will promote weight gain over the long run.",
"As an additional example, say we tran... |
[
"If Planck length is the smallest length possible, then isn't the smallest volume possible 1 cubic Planck length? Does this mean that the universe is made of tiny cubes?"
] | [
false
] | null | [
"Contrary to what you often read or hear, the Planck length is not the smallest length possible.",
"The Planck length is part of a system of units called Planck units or natural units. In this system, a number of commonly used constants of nature are set to 1, for ease of calculations (the constants drop out of e... | [
"There was actually an experiment recently that, amongst other goals, showed whether the universe was broken into Planck sized \"pixels\" or if it was continuous. Here's the wiki page: ",
"https://en.wikipedia.org/wiki/Holometer",
"And the relevant text:",
"\"A new result of the experiment released on Decembe... | [
"Just to add a little, even if there were some fundamental discretization of spacetime it ",
"wouldn't have to be cubic",
"."
] |
[
"Your input on a cosmological thought experiment..."
] | [
false
] | Sitting here wondering about how fast something travels as it enters the event horizon of a black hole. Let's say I am falling towards a black hole and I have a flashlight. I shine this flash light in the complete opposite direction in which I am falling. In other words, I shine the flashlight away from the blackhole. By definition light cannot escape the gravity of a black hole. So what would happen to the light being emitted from my flashlight? If light cant escape and the event horizon is thus the line where the escape velocity balances with the speed of light (Schwarzschild radius), and therefore beyond that point the speed at which something falls towards the singularity should be faster than the speed of light. A particle traveling faster than the speed of light would have infinite mass. If so, this would no doubt be like a puncture in space time. Well redditors, what do you guys think? I have not though this out very thoroughly as it is something I just recently pondered. Please fell free to correct me, challenge me, or maybe even expand on my thoughts. Thanks | [
"Inside a black hole, moving towards the centre is mathematically equivalent of moving forward in time, and moving away is equivalent to moving back in time."
] | [
"As you fall in photons have to climb out and get redder.",
"See also ",
"http://en.wikipedia.org/wiki/Black_hole",
" and especially ",
"http://en.wikipedia.org/wiki/Photon_sphere"
] | [
"Just to tease you, i say again that photons don't have a frequency, their wavefunctions do. The frequency observed is determined by the length of the waves you see from your frame of reference."
] |
[
"What exactly is taking place to allow a substance to exist at the triple point?"
] | [
false
] | [deleted] | [
"The three phases exist in thermodynamic equilibrium. None of the three is preferred over the other two.",
"The chemical potentials of all three phases (or equivalently, Gibbs free energies per particle) are the same."
] | [
"Do we understand how this is possible? Maybe it's jut me but I can't wrap my head around how something can be frozen yet boiling at the same temperature and pressure."
] | [
"Does each combination of two of those make sense to you? ",
"Ice melting. Water boiling. Ice in vacuum. "
] |
[
"Would a solid state-refrigerator work?"
] | [
false
] | null | [
"Thanks for that. Will post over there instead",
"Should I go ahead and delete this post then?"
] | [
"A good home for this question would be ",
"/r/AskScienceDiscussion",
"."
] | [
"You can leave the post here, no problem."
] |
[
"What prevents the \"polishing\" of any white surface to make it a mirror?"
] | [
false
] | To my (limited) understanding, the only difference between a mirror and a piece of paper is the way light is reflected off the surface, with a mirror being perfectly predictable and paper creating a bunch of "noise." They both reflect all wavelengths of visible light, but one is opaque. Is that because of the surface texture of the paper, and if so, why can't all white objects become perfectly reflective with enough polishing? If it's down to a molecular scale, is there a chemical treatment that can have that effect? | [
"I think if you take the idea out of it having to be white, it will make more sense. Copper, bronze, brass, etc. can all be polished to a mirror finish and reflect an image well, it will just be that color. You can even see yourself reflected in a screen when it goes black! So it is the surface/construction/density... | [
"s there a chemical treatment that can have that effect?",
"Saturate it with acrylic or coat it with a liquid that hardens to a polishable surface. Paper is too rough and never will be smooth enough on its own. In a microscope it's just a mat of cellulose and lignin fibers.",
"Glossy paper isn't polished glossy... | [
"if you get one of those sheets that's been stuck in the printer a while getting tumbled in there somehow, they come out a bit shinier. Don't think you can see yourself but it does take a polish with the right printer jam"
] |
[
"Are space-based solar panels different than Earth-based solar panels (and if so, in what ways)?"
] | [
false
] | null | [
"Yes! They are ",
" more expensive!",
"So, for a ground based solar panel what you care about it $ per watt.",
"\nSo to setup a solar panel for my house I would want the cheapest solution that gets me to 5kW. So I might pay between 2-8$ per watt installed. These panels will be as cheap as possible, with ce... | [
"What about micro-meteors etc? Is structural integrity taken more into account?"
] | [
"Add a layer of shielding against smaller particles, make it modular enough to handle the loss of an element from a larger impact if needed. Most damage is just minor degradation of the optical properties of the surface."
] |
[
"If our solar system is moving through space at hundreds of Km/s, does that mean Astronauts 'at rest' are as well?"
] | [
false
] | I know it's all about references frames and I assume the answer to be yes but I've never heard this really mentioned before and I wanted insight from someone who really knows. Also what does this mean for space travel? From what I can find, our solar system is orbiting in the milky way (or something along those lines) so does this movement of or solar system need to be accounted for for just about anything in space the same way you travel faster going against the earth's rotation in a plane? | [
"I know it's all about references frames",
"but from the rest of your text, I get the feeling as if you think that there is some true zero velocity. If that is so: You're mistaken. Spacetime itself doesn't care about speed, and there is no true zero speed.",
"The only kinda-quasi-objective zero speed one could ... | [
"My understanding is extremely limited so this may make no sense related to the question above but what about at absolute zero? I thought at 0K there was no molecular motion (or at least there wasn't supposed to be though I think current research has found 0K wasn't actually low enough). Wouldn't speed be 0 at ab... | [
"What you refer to is about relative movement. A particle by itself can not have a temperature. You can achieve an understanding by picturing the following:",
"Imagine a 3D isometric arrangement of balls with some space in between. Like math paper, only in 3D, and every cross section has a ball. In reality, they ... |
[
"Why is the orbit of manned spacecraft usually so steeply inclined?"
] | [
false
] | [deleted] | [
"Let's say that the space race wasn't between the US and the USSR, and instead it was Brazil that pioneered spaceflight.",
"That country can launch directly to equator orbits. When you do this, you end up with an orbit that doesn't change the latitude that it is over. So those wavy graphs showing where a satell... | [
"Yes, I looked it up and found that same fact. A simple approach would be that a launch from there would have a 5 degree inclination.",
"Plane changes are normally very costly in terms of propellant. However, if you're launching to a higher orbit (like geosynchronous satellite), you combine the plane change wit... | [
"How do launches work on the equatorial orbits? I'm thinking of French Guiana's spaceport being a meager 5 degrees north of the Equator."
] |
[
"What happens if one breathes pure oxygen?"
] | [
false
] | I've always found it particularly fascinating that the atmosphere and the air we breathe is composed of mostly nitrogen (roughly 78%), followed by oxygen (21%). How is it that we can breathe this air with oxygen being, comparatively, at such a low percentage? How would we be affected if the air we breathed was pure oxygen? (I remember vaguely reading that it is actually detrimental to breathe pure oxygen, but I can't remember how accurate that was, nor the reasons why it would be) Thank you for any input. EDIT: Thank you for all the responses! Learned quite a lot. | [
"Pretty much every bad thing you can think of",
"."
] | [
"It's actually not about either the mixture or the pressure directly. It's literally how many oxygen molecules you inhale per second. So you can say it depends both on total pressure and partial pressure together; less oxygen is less oxygen, even if there's inert gas \"padding\" it out."
] | [
"I used to work on a boat with divers, they will go absolutely ",
" if you refer to their ",
" as oxygen. Oxygen is deadly poisonous."
] |
[
"When it's said that areas of the brain \"light up\" via electrical signals, are there actual photons in the brain that get emitted?"
] | [
false
] | null | [
"I assume you're referring to fMRI (functional magnetic resonance imaging) or PET (positron emission tomography), the results of which are often talked about in terms of the brain 'lighting up'. Both don't measure electrical activity but other markers of brain activity. ",
"In the case of PET, a radioactive trace... | [
"It's possible to encounter all sorts of problems when trying to measure brain activity using BOLD, in part because the signal to noise ratio is often very low and the statistical methods ",
"aren't perfect",
". Some more detail about the BOLD response is summarised in ",
"this article",
", including some f... | [
"fMRI makes use of the fact that the magnetic properties of oxygenated and deoxygenated blood are different...The maker of activity measured is called the blood oxygenation level dependent (BOLD) response - this is based on the assumption that brain activity will use up oxygen",
"Has there ever been a situation w... |
[
"Would it be possible to build invincible / very resistant car brakes that would need little or no maintenance?"
] | [
false
] | I was thinking about it the other day as I was going to the garage to fix my brakes, again ! | [
"As long as we're still using disk/drum brakes, probably not. The stopping power comes from friction between your brake pads and the disk/drum on your wheel. In order to generate that friction, there have to be surface interactions between the two. The pads have been designed specifically to wear slightly more t... | [
"Thank you for your answer! So that means even if we took harder materials for either the pads or the disks we'd still have one of them using more than the other ?"
] | [
"Partially that, and there are other considerations. The abrasion of your existing disc brakes turns a lot of energy into heat. If you take two very hard materials and press them together, you get quite a bit more noise (read: screaming, screeching brakes). The abradable ones are much quieter. This is apparent... |
[
"What determines the ideal cruising altitude for an airplane?"
] | [
false
] | I assume various factors such as the shape, size, weight, thrust, the density of air at various heights, etc. play a role. How do these (and any others I missed) factor into calculating the ideal cruising altitude? | [
"\"Ideal\" can mean different things. Primarily, the first major factor will be the overall weight of the aircraft, and that will vary from flight to flight depending on fuel and passenger loads (the added weight of them). That will initially limit the height the aircraft can climb to (which will normally be belo... | [
"Moving air is expensive, and you need to move air out of the way to get the plane where it needs to go.",
"Turns out there is less air the higher you go, so that is a plus. It also happens to be less turbulent on average up there. Win win. Turns out you also need to keep air under the wings to stay in the sky. T... | [
"ATC's job is to accommodate pilots when possible while maintaining safety. ",
"/u/falconAF",
" is correct in saying that a dispatcher will create a flight plan profile. When the pilot files the flight plan, he gets pre-cleared by ATC, meaning they will let him fly at his desired altitude assuming nothing weir... |
[
"Can an object be in orbit while still being in the atmosphere of a planet?"
] | [
false
] | [deleted] | [
"Not stably, its orbit will degrade due to air resistance. In fact, the ISS is in the very upper reaches of our atmosphere, such that it has to periodically correct its orbit with rockets."
] | [
"Yes. It decays at about 2 km/month according to Wikipedia, so it would take about 17 years at that rate, but it would actually be faster because as it gets lower the atmosphere gets thicker and gravity gets stronger."
] | [
"just a fact we have to deal with if we want a low orbit space station",
"The cost for the fuel to periodically push it up again is lower than the savings you get from only having to launch all the crew and resource exchange missions to a lower orbit."
] |
[
"What are certain parts of animals called when you are not describing a specific animal?"
] | [
false
] | [deleted] | [
"You'd use terms like those already posted, and also directional terms. For example, if it had three things coming out the back, bottom end, you'd say something along the lines of \"the organism has three appendages posterio-ventrally.\" You'd probably also give reference to other appendages, and be more specific."... | [
"try to get your hands on a comparative vertebrate anatomy textbook if you want very precise terms. "
] | [
"Thorax and abdomen are pretty universal for dealing with the torso."
] |
[
"can someone please explain how light from a flame is electromagnetic in nature?"
] | [
false
] | My physics textbook says light shows wave and particle nature but I'm having a tough time relating this to real life. It defines EMW are caused by charges oscillating periodically to give perpendicular electric and magnetic waves. In the case of a lit candle, how do I relate this? | [
"In classical electrodynamics, the mathematics produces a wave equation which has solutions that self propagate at some speed called \"c\". These waves can impart energy and momentum onto electric charges and be produced themselves by charges. These waves are the things we call light and they travel at the speed of... | [
"I've been meaning to ask this question for a while. How do classical EM waves as the product of an accelerated charge relate to photons? Is a photon considered a quantum 'unit' of the classical wave? "
] | [
"In a way, photons are the 'units' of light. Just remember that photons come at different energies/wavelenghts/momentums. So they are not units like 1 is a unit.",
"Photons represent the invidual packets that as a whole are light. When the accelerating charge produces EM waves, it produces it in discrete packages... |
[
"On this cloning a wooly mammoth thing...I'm not a scientist, but based on the technique wouldn't the resulting mammoth have elephant RNA? And does it matter?"
] | [
false
] | Sorry if this is a dumb question. | [
"I am concerned that donaldjohnston has been unclear, so let me clarify: the egg into which the mammoth DNA is placed would contain RNA from the egg donor, meaning that they would be elephant maternal RNA and elephant proteins, including transcription factors. ",
"If the elephant RNA, proteins, and proteins trans... | [
"Thank you!"
] | [
"In this case the genome would be mammoth but the mitochondria and any extra-chromosomal DNA would be elephant."
] |
[
"Can we be sure there is nothing smaller than an elementary particle?"
] | [
false
] | [deleted] | [
"\"Elementary particles\" are such until we prove the contrary: with the current tools (e.g. LHC) we continuously look for evidence of their \"compositeness\", but no luck so far!"
] | [
"There's no proof of the existence of such things in the physical world yet: it's just specilative models at this point."
] | [
"At the moment, we don't even know what the 'size' of an electron is, if such a concept can even be applied to an elementary particle so I think it's probably a little premature to worry about anything smaller than it. :c)"
] |
[
"Would I be able to feel the difference between moving my hand through air and moving my hand through a vacuum?"
] | [
false
] | null | [
"You would feel quite a difference. If we assume that your hand wouldn't undergo any nasty side effects from being in a vacuum, more on that later, you wouldn't feel any wind resistance. In the atmosphere when you move your hand it is pushing the molecules in the air out of the way as it moves. This causes your ... | [
"The moon feather/hammer experiment was not performed by Neil Armstrong, it was done during the Apollo 15 mission by David Scott."
] | [
"Some astronaut on the moon once showed that a feather and hammer drop at the same rate on the moon which has practically no atmosphere (vacuum). The feather didn't feel anything whereas on earth it feels the air and swoops around, dropping slower than the hammer. Your hand is the feather, Daniel-son."
] |
[
"Why is Chickenpox more dangerous to adults than it is to children?"
] | [
false
] | null | [
"Chicken pox and shingles are caused by the same virus, herpes zoster. When a person first gets the disease (usually as children) it manifests as chickenpox. Once recovered, the virus still stays in body's nerve cells in a dormant state and can reemerge as shingles. So anyone who gets shingles had chickenpox at som... | [
"This is a very good question - and one that it appears has yet to be answered. ",
"The only scientifically-based information that I could find",
" is that the antiviral cytokines interferon-alpha and interferon-gamma are upregulated after varicella virus (VZV) infection. However, adults with primary VZV infect... | [
"Well actually I confess, I know of congenital varicella from personal experience. I have it. I'm one of the rare few who survive past the first few days and even rarer still that I am not too severely disabled. For me it stunted my growth as a fetus, cause my lungs, kidneys, bowl bladder and Esophagus to be deform... |
[
"How does a metal detector work?"
] | [
false
] | null | [
"The ",
"Wikipedia entry",
" describes it quite well: ",
"\"The simplest form of a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of electrically conductive metal is close to the coil, eddy currents will... | [
"Well, I wouldn't say it that way, but that's kind of the general drift. Usually the term \"electromagnet\" is reserved for something that we are using in a different way, and is constructed with a ferrous core to concentrate the magnetic field. If you use an electromagnet as part of your metal detector, be prepa... | [
"Electromagnets make object turn into electromagnet, causing coil in detector to be an electromagnet, which is detectable. Got it.... :) "
] |
[
"What is the maximum size a tornado can be?"
] | [
false
] | edit- on Earth | [
"By \"maximum size\" I'll assume you mean the \"Largest tornado path width\". ",
"The ",
" recorded occurred on May 31, 2013 in El Reno, Oklahoma; with a peak length of 16.2miles and width of 2.6 miles with 296mph winds; however this tornado was predicted as a F5 it was downgraded to a F3 [Sources ",
"1",
... | [
"Just wanted to add some info about the EF scale. The ",
"EF scale",
" is what is used now, as it takes a number of factors into account and isn't based solely on wind speed. (EF is Enhanced Fujita, F is just Fujita.) The original scale also wasn't based solely on wind speed either, but many people view it that... | [
"Not a biologist but according to ",
"this article",
" new plants can grow fruit up to 10 inches in diameter (about the size of an average pumpkin). I'd imagine that through crossbreeding with other plants that produce extremely large fruit that diameter could be pushed about 40-50% higher. (As is the case in "... |
[
"Are Organelles randomly shuffled in animal cell?"
] | [
false
] | Are they placed in a specified pattern? Or just randomly shuffled around? Are they uniform? | [
"Of course there is structure! Eukaryotic cells are filled with cytoskeleton elements such as actin filaments or microtubules. Motor proteins such as dyneins and myosin can latch on to these filaments and carry cargo. For example, this is how many marine organisms change color: by moving pigment-filled vesicles tow... | [
"What about mitochondria, then?"
] | [
"I can't think of any specific examples of the placement of mitochondria, but something else to keep in mind is that cells are incredibly, incredibly dense. Certain structures require specific places, and everything else sort of fills in accordingly. A good example is a skeletal muscle cell. Practically the enti... |
[
"what is the history behind using deciliters as a denomination for blood tests?"
] | [
false
] | how and why did this occur? it would seem to liters or milliliters would be more ”standard” than a tenth of a base unit. was μg/dl and the like simply more convenient? | [
"I don't think the units have anything to do with the amount of blood drawn for examination.",
"Think about it: a deciliter are a tenth of a liter, or 100 milliliter. That's still a ridiculously huge amount of blood for a test.",
"The normally used blood collection tubes only hold a couple of milliliters up to ... | [
"We test a ",
" of different things. Some we do use mL for, some we even use L for. In the US, it's common to adjust the denominator to make the numerator easily readable (i.e. 14 mg/mL vs 0.014 mg/dL). Over time, dL just becomes a common denominator to use for lots of things, and winds up the de facto default.",... | [
"fair enough!",
"i thought maybe there might be an interesting story behind it, as i really only encounter deciliters when reading medical papers or looking at the associated lab work on blood.",
"thanks :)"
] |
[
"What decides whether something burns up (like paper) or melts (like steel) when exposed to high temperatures?"
] | [
false
] | null | [
"Burning is a chemical reaction; the molecules in the paper react with the molecules in the air, and the role of heat is to provide the activation energy for that reaction.",
"Melting is a physical reaction; the molecules in steel are vibrating fast enough that the bonds between them cannot hold them in a rigid s... | [
"This is entirely the case. For example you'd have a hard time getting anything to burn in an argon atmosphere, and similarly hard a time stopping it in a fluorine-rich atmosphere."
] | [
"steel wool will burn in air, but melt in argon",
"im using steel wool here because of its high surface area allowing a reaction like burning to occur",
"edit: paper, on the other hand will decompose/gassify in an inert atmosphere because the bonds between molecules like cellulose, lignin and other components o... |
[
"When did animals start defecating?"
] | [
false
] | When did multi celled organisms begin to "Package" fecal matter and send it out in one lump? | [
"I'm sure there will be better answers later, since I'm not a biologist, but I'll pitch in with a bit of info to get things started. It doesn't really address your question, but it's somewhat related, anyway.",
"Excretion has always been around, since biological processes can create compounds that would be toxic ... | [
"Sooo... it's been a while since I took biology, and someone please correct me if I'm wrong, but Cnidarians were the first Phylum to have \"mouths\". They took care of all of their eating/respiration/excretion through their multi-use body cavity/mouth/anus. Those we have fossil records of I think as far back as 500... | [
"would this mean that a perfectly digestible food would not get defecated? P.S. sorry for the late comment"
] |
[
"Why is Tritium radioactive?"
] | [
false
] | So like charges repel. Protons naturally repel each other because they both have a positive charge. Am I correct in saying that neutrons are sort of like the buffer of atoms? Why then is Tritium radioactive with 1 proton and 2 neutrons? Do neutrons also repel each other even though they have no charge? | [
"It's not due to electromagnetic repulsion; the decay is due to the weak interaction.",
"Decays occur if they can. Because the mass of the helium-3 nucleus is less than that of tritium, and the mass difference is greater than the mass of an electron, tritium can turn into an electron and a helium-3 nucleus withou... | [
"The thing I didn't mention is that in order to not violate conservation of electron number, an electron antineutrino must also be emitted.",
"Also, the difference between the mass of a proton and the mass of a neutron is about three times the mass of an electron."
] | [
"The thing I didn't mention is that in order to not violate conservation of electron number, an electron antineutrino must also be emitted.",
"Also, the difference between the mass of a proton and the mass of a neutron is about three times the mass of an electron."
] |
[
"What about the world would be different if the earth’s axis was tilted 90° instead?"
] | [
false
] | null | [
"Here's a recent discussion: ",
"https://www.reddit.com/r/askscience/comments/7ahcfl/uranus_axis_is_rotated_onto_its_side_meaning_it/"
] | [
"This would be extremely interesting to see. \nIn the very middle of North Pole summer, the sun would be directly over head 24 hours a day. Any ice would surely melt. However during this time, the south pole would be facing directly away from the sun, it would spend 6 months of the year facing away from the sun. "... | [
"Ignoring climate differences and focusing just on the movement of the Sun in the sky...",
"From about 3 weeks before the March Equinox until about 3 weeks after, nothing would seem all that different. The sun would pass overhead somewhere in the tropics, moving north from the Tropic of Capricorn to the Tropic o... |
[
"How do you visualize a photon of radio frequency?"
] | [
false
] | I can visualize photons that fall in visible spectrum. Like right now photons from my screen being emitted by the backlight and hitting the molecules of my retina. Because their wavelength is of the order of nanometers, QM stops me from knowing where each single photon is at any given moment, but what about a photon of wavelength 1 meter? Does it travel like being anywhere in an area of 1 meter? I'm sorry if I'm unable to convey what I'm trying to know because if I already knew I wouldn't be asking in the first place :) In case my question doesn't make any sense, please tell me what I need to know before asking this kind of question again. | [
"They describe oscillations in an electric field, over all space.",
"ok, so a photon with wavelength 1m is nothing but oscillation of electric (and magnetic?) fields with a wavelength of 1 meter. And since no atom has electron with such low energy, they pass right through most matter, and you need large antennas ... | [
"Photons are not localized objects. They describe oscillations in an electric field, over all space. They have fixed momenta and hence, infinite uncertainty in position. X-ray photons have positions just as uncertain as infrared ones.",
"One photon of frequency 700 nm = Oscillations in the electric field over all... | [
"Yea, you got it ",
"To be pedantic : Rather than an atom having electrons with such low energy, there needs to be a process that takes such an energy as its input. Like moving an electron far away from the nucleus to a closer orbit. These energies are of the order of the frequency of visible light and range a fe... |
[
"What is the inner monologue for a deaf person like?"
] | [
false
] | null | [
"Considering that they can't imagine \"hearing\" any more than you can imagine \"sensing magnetic fields\", yes. Though from various AskReddit threads, it seems to be more a combination of visualization of kinesthetics. Kind of like if you were to imagine yourself performing the \"YMCA\" dance or something, where... | [
"The voice in your head, your inner monologue, is something we all experience all day everyday, and we \"hear\" it in whatever language it is we speak.",
"Exactly. Deaf people experience their inner monologue in the language that they \"speak\", just like hearing people do. For someone born deaf and taught sign... | [
"So they visualize their inner monologue more than they \"hear\" it? "
] |
[
"How does the immune system know it's allergic to something that touches the skin?"
] | [
false
] | [deleted] | [
"Here",
" is an excellent article on contact dermatitis. It is important to keep in mind that the skin is not a perfect barrier but a semi-permeable one. After prolonged exposure to non-protein antigens called haptens, CD8 T cells become sensitized and are recruited from lymphoid organs upon subsequent exposure t... | [
"This is perfect for type IV hypersensitivity, just bear in mind that acute urticating reactions (as in when someone swells up ",
" quickly after touching an allergen) is a different mechanism."
] | [
"Yup, type I is a very different beast. "
] |
[
"If the ozone layer was obliterated by a gamma radiation burst, how long would it take to return to normal levels?"
] | [
false
] | Would any plant or animal species be capable of adapting to something like that? | [
"Answering your followup question first - underwater species and cave species would survive without adaptation.",
"I'm not able to comprehensively answer the main question, except to state that the ozone hole (caused by human use of chlorofluorocarbons, and to a lesser extent other things) is repairing over a ti... | [
"It's worth noting that part of the cause for this timeframe in response to eliminating CFCs is that they take a couple decades to reach the ozone layer before pholyzing and reacting with the office."
] | [
"One should also keep in mind, that repairing of the ozone hole is hindered by remaining CFCs in the atmosphere. So ozone will be constantly created via sun radiation, but the CFCs are breaking down the ozone. So the actual rate of ozone layer recreationg should be higher than what me see nowadays with the repairin... |
[
"Second Universe?"
] | [
false
] | [deleted] | [
"Currently evidence does not support a \"big crunch\" scenario, which is what you're envisioning. Because the observed density of the universe seems to be below the critical density for it to overcome its observed expansion, current models predict the universe will continue to expand without end."
] | [
"While TheZaporozhianReply is correct, evidence suggests we'll continuously expand to a 'Big Chill', IF we consider your idea, which has been theorized already in the past as I'm sure you're aware, then yes, what you are describing is called the ",
"Big Bounce",
" Theory."
] | [
"While TheZaporozhianReply is correct, evidence suggests we'll continuously expand to a 'Big Chill', IF we consider your idea, which has been theorized already in the past as I'm sure you're aware, then yes, what you are describing is called the ",
"Big Bounce",
" Theory."
] |
[
"Could anyone explain the renormalizable concept of the standard model to me?"
] | [
false
] | In the book "LEP The Lord of the Collider Rings at CERN 1980-2000" by Herwig Schopper he summaries some of the results of the LEP Collider. One sentence I can't get a grip on/understand is "The proof that the standard model is a renormalizable quantum field theory, a result worth the award of the Nobel Prize to the theorists." - page 141 Help appreciated (I'm writing a paper on the failed SSC-project in the US and the successful LEP/LHC-projects at CERN) | [
"Glad to help. The key thing to remember is that if a theory is not renormalizable, it is not sensible. "
] | [
"For a quantum field theory to make sense, it must be renormalizable. If you just write down an arbitrary quantum field theory and calculate, you'll find that it generates infinite terms for essentially any process, and even if you impose a rule to make one or two or five processes finite, the others remain infini... | [
"Thank you for the explanation. It didn't make a whole lot of sense the first time I read it, but now I believe I have a grasp on the concept",
"Cheers mate!"
] |
[
"What is the next, most basic scientific breakthrough we would need for a complete global impact?"
] | [
false
] | null | [
"A technique to rapidly (re)generate soil and humus that doesn't require a shitton of water. This would allow to reclaim deserts as arable land. Increasing food production and water retention",
"Currently, you can take waste organic material such as cellulose (grass, paper, ...) and use fungi (such as mushrooms) ... | [
"Although now I believe you probably know where to hit your head to get superpowers or something and you're keeping it secret.",
"It's actually about how to insert the Q-tip up your nose really far and get superpowers, but close!",
"Maybe try ",
"/r/PhilosophyofScience",
" ??"
] | [
"We don't allow broad general questions like this, sorry. All the best!"
] |
[
"Will Voyager 1 eventually slow down/stop due to drag caused by gas and dust in interstellar space?"
] | [
false
] | I was reading about Voyager 1 today, and found out that it is quite close to leaving the heliosphere, after which it will come into contact with interstellar gasses. Is this likely to slow it down? Or even stop it? | [
"interstellar gas is almost non existent (a few atoms per meter) so there is very little matter to actually interact with. Think of the mass of these few atoms vs the entire mass of voyager - many orders of magnitude different. ",
"If you mean slow it down relative to its current direction of travel something w... | [
"The interstellar gas within the galaxy is actually of density ~1 atom per cubic centimeter. It's the intergalactic space that averages more like 1 per cubic meter."
] | [
"voyager is travelling at 17 km/s it weighs 733 kg so ",
"ke = 1/2mv",
" = 10",
"ke",
" = 1/2*(733000)*(1700)",
" = 10",
"assuming perfectly elastic collisions and all dust is hydrogen atoms",
"ke",
" = 1/2*1.6*10",
" *17000",
" =2.3*10",
" ",
"to slow down by 1 order of magnitude it would t... |
[
"What is it exactly that energy boosting substances like caffeine and ginseng do to our body in order to provide an alert/energized state?"
] | [
false
] | null | [
"Well, for caffeine, it doesn't actually give you energy. Caffeine is an adenosine receptor antagonist. It prevents adenosine from binding to sites in the CNS. Over time as you are awake, adenosine builds up and begins binding to these receptors which induces drowsiness, but with caffeine in your system, this is bl... | [
"Wow that's really interesting! In that case I wonder how it manages to \"perk up\" someone who is already tired if, mechanically, it more staves off drowsiness more so than providing energy.",
"Placebo effect perhaps? "
] | [
"Being tired means adenosin is docked at the receptor and activates it and that makes you feel tired. If caffeine as an antagonist docks there, too, it \"pushes away\" the adenosin and blocks he receptor without activating it. Think of it like a bouncer at a club. He comes and prevents people from entering but does... |
[
"Put a cup of water in front of speaker, doesn't vibrate?"
] | [
false
] | [deleted] | [
"Sound is basically a medium vibrating back and forth. First the air vibrates back and forth, and that's transferred to the glass, and then the water."
] | [
"It could also just be that you're not seeing the vibrations. What frequency is the speaker playing at? Try deep bass with high volume. Also, try turning the speaker so it's facing up and putting the glass on top. And maybe mix some corn starch in with the water."
] | [
"There are many pictures and videos around if you're worried about breaking things. (which you should be)"
] |
[
"What were cows like and how were they able to survive before being domesticated by humans?"
] | [
false
] | Slow, docile, seemingly defenseless. I know all these traits were preferred and actively chosen thru thousands of generations of selective breeding by humans, but what were the progenitors like? | [
"Many large herbivorous animals are able to survive through sheer size (the larger you are, the less likely you are to become prey) and ",
"numbers",
". Also, ",
"aurochs",
" (ancestor to the modern cow), modern cows, and many other ungulates have horns. ",
"Docility and tameness can happen within a ",
... | [
"Aurochs were serious beasts, well-respected by contemporary hunters. They were swift and fast, and could get very aggressive if provoked. There were probably no non-human predators that could normally take down a healthy adult individual. "
] | [
"The aurochs was the progenitor of the domestic cow - and for that matter, I wouldn't entirely count out the defenses of cattle. They're big, and strong, and many of them have horns. Bulls remain famously dangerous, and rodeos are largely about how dangerous even domestic cattle can be.",
"That's after all the do... |
[
"Are Thymine, Adenine, Guanine, and Cytosine present/used in DNA of all living organisms on earth?"
] | [
false
] | Are there any organisms anywhere that dont use ATCG DNA or a variation of it? | [
"As far as I’m aware, all DNA for living things is made from ATCG on Earth. There are viruses and such that use single and double stranded RNA which contains uracil instead of thymine, but those are generally not considered to be living things. "
] | [
"The cell is considered to be the smallest unit of life in the world of science, yes. Viruses are not made of cells though or are a cell themself. Viruses are made of proteins and form capsules that carry genetic information. Why are they not considered living if they have some form of genetic code? Because they ca... | [
"Thank you for your answer, it is quite thought provoking.",
"What does it mean in this context when a virus is not considered living? I was under the impression that all cellular-based things on Earth were living - dogs, birds, grass, spiders, trees, algae, iguanas, etc.",
"How can a nonliving entity reproduce... |
[
"Does light have mass?"
] | [
false
] | null | [
"No it does not. It doesn't need to do the things you're describing. It still has momentum. Light consists of electric and magnetic fields. Electric fields move things, magnetic fields move things, and neither of those has mass."
] | [
"Why do you ",
"keep",
" ",
"asking",
" this question?"
] | [
"My Alien Blue app must be bugged. It says it never posted. I apologize for multiple posts!"
] |
[
"Is all \"sense\" DNA on the same strand of a double helix (i.e. is one particular strand always the one that gets copied)?"
] | [
false
] | Transcription is the process of copying a section of "sense" DNA into a strand of "anti-sense" RNA. When transcription bubbles are created, what prevents the anti-sense DNA from being transcribed? Furthermore, is all "sense" DNA on the same strand of a double helix (i.e. is one particular strand always the one that gets copied)? | [
"No. The coding sequence for a gene can reside on either strand of the DNA and hence, there is no fixed strand of DNA that RNA is always transcribed from. As for what's preventing antisense RNA from being transcribed, that would be the gene regulatory elements that are found upstream of a gene. For gene transcripti... | [
"You are indeed correct. Sense should refer to the sequence you can read directly for the protein sequence. Hence, the sequence of the DNA that will be transcribed into RNA is actually referred to as antisense. I have corrected and reworded my answer."
] | [
"You are indeed correct. Sense should refer to the sequence you can read directly for the protein sequence. Hence, the sequence of the DNA that will be transcribed into RNA is actually referred to as antisense. I have corrected and reworded my answer."
] |
[
"Absolute zero and gas laws"
] | [
false
] | According to Gay-Lussac, Boyle, and Charles' laws wouldn't absolute zero bring us to a point where we can make something with no pressure and a negligible amount of mass? If that is the case couldn't we eventually (if we do reach absolute zero) compress liquids for long space travel? Or is there some quantum physics stuff that I am missing that makes this impossible? | [
"An ideal gas has zero volume at zero temperature. However, gasses aren't ideal under all conditions. Ignoring the fact that gasses turn liquid or solid at low temperatures, eventually they behave more like van der Waals gasses and you have to take into account their interactions and finite volume."
] | [
"We can't reach absolute zero."
] | [
"The third law of thermodynamics."
] |
[
"Is the need for sleep still not understood? If so, what are the current leading theories for why animals/humans need sleep?"
] | [
false
] | null | [
"Not sure if this has been answered, but I'll give a quick summary(it says 4 comments on the post but nothing is visibly deleted).",
"There's a lot of thought that some of the \"brainwaves\" we see during sleep (non-dreaming sleep, specifically) are linked to learning/memory during the day. A couple interesting ... | [
"There is also recent evidence that the brain waits until sleep to activate some of its waste-clearing mechanisms, this providing a vital period in which the brain prepares for its high metabolic rate during wakefulness."
] | [
"Yeah it's something of a tradeoff. Though I'd baselessly speculate that social living helps."
] |
[
"Can we engineer \"evolution\" in small organisms (e.g. bacteria) in short periods of time?"
] | [
false
] | For example, if we have heat up bacteria in a petri dish to 45 degrees celsius, are we genetically selecting for bacteria that can survive in that temperature? Or if we expose it to chemicals (like soap), are we creating super-bacteria? How long would it take to see meaningful changes in the genetic structure of this bacteria, as compared to larger organisms such as plants and animals. | [
"Just adding on to point out that this is abundantly, extremely commonplace in microbiology research, and has been for various purposes for decades. A common teaching lab demonstration of this in undergrad and even high school courses is to generate antibiotic resistant bacteria by creating gradient media and inocu... | [
"Well thats No science fiction but reality. ",
"You describe mutant screenings. \nIf you want to analyse new pathways but don't have a starting point you create Mutants by radiating them with radioactive substances. (Or other mutagenic substances)\nThen you look what is different and analyse the genome. After thi... | [
"Yes we can! The 2018 Nobel prize in chemistry went to Frances Arnold, George Smith and Gregory Winter for this exact type of work.",
"There’s also a great video out there, not sure made it (maybe Harvard), that shows the growth of bacteria on a huge petri dish with differing amounts of antibiotic, and certain st... |
[
"How does an Archimedes Screw work?"
] | [
false
] | An was used historically for raising water for various purposes. It consists of a helical "screw" inside of a pipe, and as the screw is turned, the water level within the pipe rises. Some descriptions detail a series of wells along the screw that scoop up water and transport the water to the top of the pipe. However, I do not understand how the water actually rises. If the wells are stationary along the screw, how would the well rise as the screw is turned? | [
"The animation in the article isn't the best.",
"Think about a stationary screw inside of a closely fitting column, and the whole thing nearly parallel to the ground but at a slight angle. Now consider the area around just one bit of the screw's thread. If you think about it it should be obvious that you can hold... | [
"I just had an A-Ha moment. The cavity is not a divot in the thread of the screw. But the bottom of the cavity is the side of the pipe, and the sides of the cavity are the threads of the screws. Thanks for the explanation!"
] | [
"The screw itself moves the water. Look at the animation in the wiki article. The balls are being carried along by the screw itself as it turns. Each ball rests in the lowest area it can roll to, the bottom of the screw area it is in. As the screw twists, these areas are raised higher and higher and the ball so... |
[
"Is there a metal that heats up slowly, yet disperses heat quickly?"
] | [
false
] | Metals such as aluminum are excellent conductors of heat, but they distribute changes in temperature, whether that be an increase or decrease, quite quickly. Is there such a metal that would heat up slowly (say several hundred degrees above ambient temperature), yet disperse that heat much faster than it was gained? Is such a material even possible? | [
"My understanding is that heat capacity depends on temperature, so if the metal heated up slowly at a certain temperature (that is, required a lot of energy to increase the temperature) it would also lose heat at that same rate at the specific temperature. There may be something that would, let's say, heat up slowl... | [
"This is correct and it's called the \"specific heat\". It's the amount of heat per unit mass required to raise that mass by one degree C. ",
"If you're thinking of making a better heat sink, you should know that those work by increasing surface area. Aluminum works well because it has a low specific heat. The go... | [
"I was indeed thinking about such a material's application in a heat sink."
] |
[
"Is the belief that a comet triggered the Cretaceous–Paleogene extinction still the most widely held belief?"
] | [
false
] | If so, can someone explain to me how a comet could have triggered such a mass extinction? | [
"In general, the idea that the object that made the ",
"Chicxulub crater",
" is at least partially responsible for the K-Pg mass extinction is not really controversial. However, there has been some suggestion that the late Cretaceous was already a somewhat difficult time for many large vertebrates, and so this... | [
"Oh, and as for the second part of your question which I didn't see before, the details of how this mass extinction would have unfolded after the impact are somewhat variable depending on who you ask, but the overall picture is pretty consistent. Obviously, anything living in the immediate vicinity of the impact w... | [
"Thank you! That was very detailed and well referenced. I appreciate the effort you put into that response"
] |
[
"What would it take for a fungi virus, such as cordyceps, to mutate and become a threat to humans?"
] | [
false
] | null | [
"Earth Sciences"
] | [
"Earth Sciences"
] | [
"Earth Sciences"
] |
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