title list | over_18 list | post_content stringlengths 0 9.37k ⌀ | C1 list | C2 list | C3 list |
|---|---|---|---|---|---|
[
"How important is the way that we breathe?"
] | [
false
] | [deleted] | [
"What do you mean? Chest vs abdominal breathing or nose vs mouth breathing. ",
"For breastfeeding children, they are primarily nasal breathers, and are able to both suckle and feed and breathe at the same time. Because their nasal airway and oral esophageal pathway are closed off from one another. This however ma... | [
"Physical therapist here.",
"It’s true that adults tend to become chest breathers, and many become neck breathers (using their neck muscles to help the lungs expand. ",
"Over time and disuse of the movement, many adult lose their ability to breathe diaphragmatically (abdominal breathing), which becomes a proble... | [
"Nope, that’ll pretty much always do the trick! ACSM guidelines suggest 30 minutes of moderate cardio (intense enough to make you breathe hard and sweat) 3-5 times a week, and that’s appropriate for most older adults as well. ",
"There is unfortunately a large segment of the adult population that doesn’t do that.... |
[
"If somebody across from me on a large field shot a gun while holding a walkie talkie with the speak button on, would you hear the sound first on the walkie talkie or from the sound itself?"
] | [
false
] | null | [
"Walkie-talkies use radio frequency electromagnetic waves to transmit signals. These propagate with the speed of light, approximately 300,000 km/s. On the other hand, sound from the gunshot (or any other sound) will travel at about 340 m/s (precise value depends on atmospheric conditions).",
"For all intents and ... | [
"Incidentally, Admiral Grace Hopper ",
"had a fantastic 2-minute demonstration",
" that puts the speed of light into tangible terms. While it's convenient to discount the travel time of light as \"instantaneous\", in some situations (not this one, of course) it definitely makes a difference!"
] | [
"For those of you who don't know who ",
"Grace Hopper",
" was:",
"EDIT: This summary doesn't even do her justice. There's just not that many people of her caliber."
] |
[
"Has anyone ever attempted a computer-based ecosystem?"
] | [
false
] | null | [
"This is more ground-up than what you're describing, but it is fascinating:",
"http://en.wikipedia.org/wiki/Conway%27s_Game_of_Life"
] | [
"Ecologists have been developing very simplified models of ecosystems for a long time. The famous ",
"Lotka-Volterra",
" model of predator-prey interactions was developed in the 1920s, for example. Ever since, more and more complex models have been developed to understand more subtle ecological interactions. Yo... | [
"This is instantly what I thought of. However, Conways' game of life while showing some simple \"organisms\" is more or less mathematical physics (still falling short of the great complexity we see in biological systems). The big thing here is that the system of rules has emergence, self-organization and later it w... |
[
"Why is there dust on the moon?"
] | [
false
] | If there is no atmosphere how is there dust? The sand on earth is created by erosion from wind, sun and sea. How did the dust on the moon get there? | [
"It's formed by impacts - everything from large to micrometeorite events. These generate not only fine particles, but also rock vapour which then re-crystallises onto existing grains.",
"https://gsa.confex.com/gsa/2008AM/finalprogram/abstract_152612.htm"
] | [
"Pulverized rock from meteor impacts most likely."
] | [
"There's dust in space which makes its way to the moon. Also when ",
", stellar bodies, maybe a better word, of that type form, there's local dust that eventually gravitates toward the planet.",
"Related: Since there's no erosion on the moon, moon dust can be pretty shard-like. Comparatively, dust and dirt here... |
[
"[Medicine] How does limb reattachment work?"
] | [
false
] | I've seen examples of limb reattachment on TV, from fingers to hands to legs. But how does this process work? How is it possible for a body part to be completely cut off, yet still be able to function again if attached properly? (I know this is probably insanely complicated, but a simple-ish answer would satisfy my curiosity) Bonus: Is there a special title for a surgeon who does this? | [
"This is known as ",
"replantation",
". ",
"For digit and hand replants, you basically repair and reattach the bones, then tendons (to provide support for other soft tissue structures), followed by connecting the arteries, veins, and nerves via very delicate suturing. ",
" ",
"In the majority of amputati... | [
"And then the body's natural healing processes take over? ",
"If so, what conditions are necessary to trigger the body's natural response? Like, does tissue need to be within a certain distance, or touching, or connected via fluids, etc? Also, do we ever see cancerous and other abnormal growths during the healing... | [
"There is one thing I never understood that I'm reminded of reading this thread.",
"When somebody breaks their neck and severs their spinal column, we're currently (as far as I'm aware) unable to repair the severed nerves, leaving the person a quadraplegic, yet when a hand or finger is severed it can be reattache... |
[
"Can I use my phone camera to look at the eclipse?"
] | [
false
] | Ok. I know you aren't supposed to look at the sun directly (duh). But during the eclipse, suppose I put my phone up so it blocks the sun fully and record a video.. That would be safe, wouldn't it since I'm not looking at the sun per say, but my screen showing the sun... Right? I just want to make sure I can do this before I try it. :) | [
"It's safe for you, and most digital image sensors are pretty well protected. If you're taking short exposures (<1 second) both you and the camera should be fine, just don't spend a lot of time lining up your shot."
] | [
"Well, that's what I mean.. I'm not talking about taking a quick shot.. I'm talking about taking my cell phone, covering up the sun and starting a video recording for the whole eclipse.",
"I would be viewing it in real time ala iron man heads up display.",
"Would this mess up the cell phone camera or my eyes do... | [
"Your eyes no, but to find out the potential long term damage to your cell phone you'd have to get the specs from your manufacturer. It will vary by sensor. However, you could do a simple old trick - if you can find any old film negatives (uncommon these days) or a couple of pieces of neutral density filter and p... |
[
"Are there any negative health effects from consistently going to bed around 5am and waking up at 2pm?"
] | [
false
] | null | [
"Yes, though I doubt it's permanent. Virtually every process in your body - metabolism, immune response, tissue regeneration you name it - is tied to the circadian rhythm, a 24 hour cycle maintained by a proteinaceous clock within each cell. ",
"The clock is synchronized by a group of light sensitive neurons, so ... | [
"There is a tremendous host of problems associated with shift work. If you want more information, I would recommend googling \"harvard nurses study night shift work.\" (But there's more available than just through the harvard nurses study.)",
"That may or may not be relevant to your situation. Somebody volunta... | [
"Oh hell yes. Some examples effects, interfering with your liver's night janitor job that happens between 3-5 AM and which gets your blood cleaned up for the next day. Result dirtier blood during your awake time which leads to less concentration, greater irritability, poorer digestion, and therefore poorer quality... |
[
"Why do so many medicines make you higher risk for TB infection?"
] | [
false
] | Seems like every commercial for medication lately warns of higher TB infection rate and to tell your doctor if you've been anywhere outside the US lately? | [
"Generally those medications suppress your immune system as part of the way that they treat the symptom for which they are prescribed. Autoimmune diseases like rheumatoid arthritis, psoriasis, and Celiac disease are due to your immune system reacting to your own body. To treat this, the medications suppress a part ... | [
"To expand on this, TB typically forms granulomas in the lungs which is the best way our immune systems can deal with TB. Throw as many cells as soon possible until it's covered in so many layers that the TB cells can't interact with anything. ",
"It's difficult to say if this is how our immune system has evolved... | [
"Autoimmune diseases like rheumatoid arthritis, psoriasis, and Celiac disease are due to your immune system reacting to your own body.",
"Just a small correction: They react to an offender/allergen.",
"In some cases the trigger is known like in Celiac or little understood like in the others."
] |
[
"Why does sound travel faster in less dense gas like helium but slower in denser gas like argon?"
] | [
false
] | null | [
"Because the molecules are lighter. Imagine a long train with many wagons connected by springs. If you move the first one a bit you should have enough intuition to believe that this will start a wave of motion of the wagons down the length of the train. If the wagons are heavily loaded the springs will be contracte... | [
"So why would sound traveler faster in solids and liquids water? Sound travels much faster and further in water and steel than in gas."
] | [
"Basically, the molecules in a solid or liquid \"feel each other\" more than molecules in a gas, so their stiffness is higher, increasing the speed of sound. It is important, though, not to confuse this with density. Just as in gases, a solid with the same stiffness but higher density will have a slower speed of so... |
[
"What is mainly heating the earth? The sun or the core?"
] | [
false
] | I learned that Saturn at the North Pole is about 30ish degrees while near the equator it is way colder than from the poles. Since saturan is way father from the sun than it is from earth, does earth gets most of its heat from its core or from the sun? | [
"Depends. The inside of the Earth gets almost all its heat from the Earth itself. Not just the core.",
"Almost any temperature on the surface of the Earth will be dominated by the sun's influence far, far more than the internal temperature (unless you are standing over something volcanic).",
"The sun's heating ... | [
"Yeah, heat generated within the Earth eventually reaches the surface and radiates away. Mostly it is just retained within. The sun's energy input vastly outmatches what the Earth produces (surface area doesn't make a huge difference) but it radiates away very quickly.",
"Basically, Earth is capable of radiating ... | [
"I assume you mean heating the Earth's surface, so I'll answer that. ",
"This paper from 2010",
" says that the heat flux at the surface of the earth due to internal heat is 47±2 terawatts (TW) or about 47 trillion watts. That sounds like quite a bit but now let's look at what's coming from the sun. ",
"NA... |
[
"If you burn radioactive paper does it change the radioactivity?"
] | [
false
] | Well... I think my title says it all. Thanks. | [
"Not typically. Radioactivity is usually a much more a property of just the nuclei of the atoms in the material, so is not substantially effected by chemistry like burning, which is the effect from the electrons orbiting the atom.",
"There is, however a small change in decay rate for those atoms which undergo de... | [
"I saw the thread about the Curie notes still being radioactive and it got me thinking. Thanks for the info. "
] | [
"Her papers are contaminated with Radium-226, which decays via ",
"alpha emission",
", which should be almost perfectly independent of chemistry."
] |
[
"Can you short out power lines using Mylar balloons?"
] | [
false
] | This question was prompted from . A character releases a bunch of Mylar balloons which make contact w/ a power line, creating huge sparks and disrupting power to a nearby building. Mythbusters of reddit, please tell me: Could that work in real life or is this just some TV magic? | [
"Let's clear up a basic misunderstanding: Mylar is Dupont's term trademark for biaxially oriented PET film. It is a very clear film that you can see through. It can be used as is, or it can be printed on and/or metallized.",
"For some reason that I've yet to understand, people think that Mylar is only the metalli... | [
"Yes",
"http://www.youtube.com/watch?v=XPqL6alKALQ"
] | [
"Thanks!"
] |
[
"Is it in the foreseeable future that we will be swallowed by a black hole?"
] | [
false
] | After reading an article by iO9 ( ), which talked about the two largest black holes ever found, I started to wonder this. Would we all be killed somehow by something sooner? Would the black hole be from our galaxy or another one, and how would it get here? | [
"Standard post:\nBlack holes are not cosmic vacuum cleaners. If my laptop suddenly turned into a black hole now I would not be sucked into it.\nIt would still exert the same gravitational force on me as it is at the moment."
] | [
"As long as you don't try to type on it, right? If you put a part of yourself inside the event horizon, then you'd be goners?"
] | [
"because of the small mass of his laptop he would have to get very close to the event horizon to feel the extreme gravitational pull. Obviously the event horizon itself would be so tiny, it wouldn't be directly observable (actually it isn't either way, ha-ha), because it is directly related to the mass of the black... |
[
"Is there a difference between having a 2 hour nap then 6 hours sleep and just having an 8 hour sleep? Brain wise?"
] | [
false
] | So what usually happens to me is that I arrive home from school, and usually have a two hour nap. Lets say from 5pm - 7pm. Then I stay up until 12am and wake up at 6am. Is there a difference if I stay up until 10pm and sleep till 6am? Does anything happen in brain function? | [
"This study",
" found that there is no difference between 8/0 and 6/2 schedules in terms of cognitive performance. They tested different combinations of nighttime sleep opportunities (ranging 4.2-8.2 h) and afternoon nap opportunities (ranging 0-2.4 h). Performance had a near-linear dependence on the ",
" (day+... | [
"Probably not without problems, for two reasons. First, there are times of day at which it is very difficult to initiate sleep and maintain consolidated sleep. Schedules that involve trying to sleep outside of the biological night or afternoon siesta time are therefore a struggle. Second, this is going to really di... | [
"Could you then have four 2-hour naps throughout the day and never have to \"go to sleep\" in the traditional, continuous sense?"
] |
[
"How can organisms that reproduce asexually evolve, if at all?"
] | [
false
] | [deleted] | [
"Asexually reproducing organisms show much less variation in DNA as compared to sexually reproducing organisms.\nHowever, when an asexually reproducing organism like a bacterial cell is about to divide, it needs to replicate its DNA. This DNA replication is not always perfect, and errors can be introduced. Thus, th... | [
"Asexually reproducing organisms show much less variation in DNA as compared to sexually reproducing organisms.",
"I'd say that it's the mixing/matching of sexual reproduction that allows more combinations to be tried, not the rate of mutation."
] | [
"I agree. I meant that the high variation observed in progeny of sexually reproducing organisms is a result of recombination instead of mutation"
] |
[
"If the distance between water jets increases the further away I am from the shower head, why aren't there perceptible gaps in light being emitted from very distant stars?"
] | [
false
] | null | [
"There actually are gaps in the light emitted by distant stars, however, this is perceived by us as a change in the light intensity. When we see a star, we are seeing the photons emitted by that star. The farther you get from the star, the less photons impact your eye and the less intense the light becomes. In f... | [
"Just for fun, I looked up the number of photons emitted from a 60 watt light bulb. I didn't do the math on this, but it looks pretty good. ",
"Source: Bucknell's Astronomy 101 page",
" A 60-watt light bulb emits 60 joules/sec of energy ( 1 Joule/sec == 1 watt). Pretend for a moment that all of this energy is... | [
"Thank you for your answer!",
"I'm trying to imagine the sheer number of photons that would need to be emitted from a star to still provide a somewhat steady \"shower\" of photos at such a great distance. It seems impossibly large."
] |
[
"How much thinner is the air at cloud level?"
] | [
false
] | In a percentage, if possible. :) Oh, and I guess I'm talking about normal day time clouds, whatever altitude those reside at. | [
"There are lots of clouds visible during the day, and they occupy a range of heights. If you want to calculate air pressure at a given altitude, you can use this formula:",
"P=(1 atm)*(1 - (height in km)/(44.3 km))",
"So, plugging that in for a few common cloud types:",
"Stratus clouds",
" are the uniform,... | [
"Your average fair-weather cloud is a cumulus cloud. Cumulus clouds are usually below about 1000m. The standard atmosphere tells us that the density of the air 1000 m above you is about 85% to 90% of the density of the air where you are (the ratio gets closer to 90% as your starting altitude gets lower, and close... | [
"Thanks, and extra thanks for giving me more cloud types. I had no idea the atmosphere 'dropped off' that fast."
] |
[
"How do microscopic black holes behave?"
] | [
false
] | When I say microscopic, I mean black holes that are small enough that they behave like quantum mechanical particles. What would such a black hole's wave function look like? Could you model their behavior as a field theory where the black holes are the excitations? Does such a theory shed light on quantum gravity? | [
"In a sense, microscopical black-holes are just like very weird scattering-matrices. They form and immediately decay into many soft quanta, so they just act as scattering amplitudes for quantum processes. ",
"The only way we can ever observe micro black holes in experiments is if we have additional dimensions. In... | [
"That was an asteroid, not a blackhole, I believe."
] | [
"Not even a little..."
] |
[
"Why was such a massive, fundamental particle like the Higgs Boson so hard to find?"
] | [
false
] | I mean, it seems kind of obvious for something tiny like the neutrino to have been difficult, because it's so tiny and barely interacts with anything. But the Higgs, as I've heard described, is both massive... Like, much heavier than a proton or neutron, and also has to interact with all matter for it to have any mass at all. What's the issue? Also, same question for gravitons I guess. | [
"Having a large mass doesn't make things ",
" to study, it makes them ",
" to study. The Higgs boson is not stable; it decays with a lifetime around 10",
" seconds. So you can't find Higgs bosons in nature, if you want to study them, you need to produce them using a collider.",
"The more mass your particle ... | [
"Then the question would be, how can something described as so short living interact with all of matter to give everything mass?",
"The Higgs boson itself doesn't give particles mass. It's interactions with the Higgs field which gives particles some of their masses. So even though all of \"normal matter\" interac... | [
"The Higgs ",
" gives particles their mass. The Higgs boson is an perturbation in that field (any particle is a perturbation of its respective field)."
] |
[
"What is stopping people from broadcasting at frequencies of radio stations?"
] | [
false
] | null | [
"Well that is regulated by the FCC. They will actually drive around and look for illegal broadcasts at different frequencies. I know because where I work we have some older wireless microphones that broadcast at the frequency of 3g radio towers. If they were to find us broadcasting they would find us and fine us... | [
"The FCC. If you set up your own radio station without a license, it's not hard to find you - just follow your radio signal!",
"But there have been ",
"pirate radio stations",
" in the past, and there ",
"might be some now",
". The UK is a good place for it, since England is a small island, and you can se... | [
"So let's say someone started broadcasting at the frequency of some other big radio station. Would it be possible to \"over take\" the waves of the other station, or would they just merge and create static in car radios?"
] |
[
"How can the Universe be infinite if it \"started\" at a certain time?"
] | [
false
] | I understand that the universe is expanding extremely rapidly, but nothing can expand in an infinite manner. | [
"If the universe was infinite at its start then there's no problem with it still being infinite. It's just less dense."
] | [
"So the Universe did not start as an infinitesimally small point?",
"yes, it did.",
"No, it didn't. The Universe was infinite to begin with, however infinitely dense and hot as well. "
] | [
"We don't ",
" how it started. It could quite possibly have been a single point at time t = 0 and then been infinite for all times t > 0."
] |
[
"Hurricane Patricia Megathread"
] | [
false
] | Come here to ask all of your questions regarding "the strongest hurricane ever known to assault the Western Hemisphere" : Hurricane Patricia Strikes Mexico With 165 M.P.H. Winds : How Hurricane Patricia Quickly Became a Monster Storm | [
"[In an ideal world,] how much harvestable energy is in Hurricane Patricia?"
] | [
"NOAA actually addresses the question of Hurricane energies in ",
"one of their FAQs",
":",
"Subject: D7) How much energy does a hurricane release?\nContributed by Chris Landsea (NHC)",
"Hurricanes can be thought of, to a first approximation, as a heat engine; obtaining its heat input from the warm, humid a... | [
"If you mean \"what is the strongest possible hurricane\" (highest wind speed and lowest pressure), then Patricia is essentially it. Kerry Emmanuel, who is one of the most respected hurricane researchers, developed a \"",
"maximum potential intensity",
"\" index, which when applied to Earth's climate as it is n... |
[
"What do the “A’s” in batteries stand for?"
] | [
false
] | What does it mean and what is the function of having two AA’s vs having say 4 AAAA’s? | [
"The dry cell battery was invented in 1888, and by World War I there were lots of manufacturers making lots of different batteries, in different sizes, voltages, materials, etc. The US government came up with several of its own standards for describing batteries, in rapid succession.",
"Then in 1924, the manufact... | [
"Fun fact, pretty much every household in the US has a bunch of AAAA batteries, though most people don't know it. 9V batteries are simply 6 1.5V quadruple A batteries connected in series to give 9V.",
"http://www.rfcafe.com/references/electrical/aaaa-cells-inside-a-9volt-battery.htm"
] | [
"Huh, I alwys thought 9v batteries were a stck of squat semi-rectangular cells."
] |
[
"Could someone explain what it takes to destroy organic molecules?"
] | [
false
] | Curious because of this article . Edit: What are the limiting factors of life originating from asteroids? What needs to happen, besides time and a "habitable" location, for life to not take hold in a solar system? | [
"Define \"destroy.\""
] | [
"I'm not asking for a dictionary definition. I'm asking what ",
" mean by it.",
"You could mean \"completely annihilate,\" in which case my answer would be to use antimatter to \"destroy\" organic compounds. That really is the only way to \"annihilate\" matter.",
"Or if you mean \"reduce to useless fragments,... | [
"Do you know, offhand, at what temperature and pressure would CH bonds start to come apart?"
] |
[
"How to say certain complex chemical formulas?"
] | [
false
] | Hi there. Anyways, been doing some chemistry stuff and I've been thinking; how do you say some more complex chemical formulas? (especially stuff with parentheses/brackets) For example, the chemical formula for azurite, Cu3(CO3)2(OH)2. Thanks! | [
"Cu = copper\nCO",
" = carbonate\nOH = hydroxide",
"The parentheses group the items so you know that there are two carbonates and two hydroxides.",
"Azurite's chemical name is quite boring. Copper(II) Carbonate hydroxide. To see more on naming rules for inorganic compounds, start ",
"here"
] | [
"You'd say \"azurite\" :) If I ",
" to say it, I'd read it as written (see-you-three-see-oh-three-two-oh-aych-two), but a better thing would be to say what that formula is describing; something like \"the unit cell of azurite has three coppers binding two carbonates and two hydroxides\". But drawing the thing is ... | [
"In grad school one of my profs said that the hardest part of writing articles for him and his students was naming any new compound. If they were lucky they'd find a named compound that had different functional groups to their's but otherwise the same connectivity and just replace where necessary.",
"And you're ... |
[
"Cause of flu/cold symptoms"
] | [
false
] | After recovering from the 24hr stomach flu, I had to wonder, what exactly causes the symptoms that I had. How does the attack of the virus in my body translate to body aches, nausea, headaches, etc, etc.? Likewise, how does the same work with cold symptoms? Whats the difference? | [
"A virus will infect and take over the cells of the body, it will then use the cells own machinery to replicate and spread. Usually this does not cause any symptoms but will become a larger problem if left unchecked. The immune system, when it kicks in and develops a response the the specific virus, will kill all i... | [
"Vomiting and diarrhea are common symptoms of gastroenteritis, when this is caused by a virus this is called viral gastroenteritis. Usually in this case these symptoms are a result of damage and inflammation of the epithelial cells lining the gut/intestines by your immune system trying to remove the virus, or throu... | [
"So then what about the vomiting and diarrhea? How is that reasoned to be a \"useful\" immune response? Are these side effects of a deeper response?"
] |
[
"Why when I wear flat shoes do my feet get sore? Shouldn't evolution of humans walking without shoes have shaped my feet to accommodate this?"
] | [
false
] | When I wear flats (or any shoes with virtually no support) after a long day my feet are sore, specifically the arch. Why would evolution from years of our ancestors wearing poor shoes or no shoes in the past not have fixed this to this day? | [
"Wearing flat shoes is not equivalent to wearing no shoes: flat shoes limit the ability of your foot to stretch and spring in comparison to an unshod state.",
"Also, we don't have a comparison of you in the same health using the same activity with a variety of different footwear conditions, including barefoot, so... | [
"That probability is for ",
" mutations. The probability is higher if selection favors the mutation. "
] | [
"Why would evolution from years of our ancestors wearing poor shoes or no shoes in the past not have fixed this to this day?",
"We haven't hardly lived long enough or unifiably worn shoes for that to matter; evolution to the degree that you are talking about does not occur that rapidly."
] |
[
"Have we seen evidence of a fourth or higher spatial dimensional universe by looking at everyday natural objects in this, our three dimensional visible universe?"
] | [
false
] | [deleted] | [
"No, but you can read about attempts to do so ",
"here",
"."
] | [
"A 4-d object would appear to be able to violate conservation of mass, or teleport, or be in 2 places at once. Let me give a 3d to 2d analogy. ",
"If you have people living in a 2d word, a sphere passing through it would appear as a circle that can grow to a max size, and then shrink back to nothing. A ring pu... | [
"I tried to write a system that treated entangled particles as bound through some sort of subspace in high school. When I showed it to a professor they pointed out that I added a ton of assumptions for no real benefit. You don't gain extra predictive power.",
"If we observed some sort of particle emitted from o... |
[
"Is there an \"ideal length\" for a nap?"
] | [
false
] | null | [
"About 30 minutes, give or take 10. Its enough to send you into a stage 2/3 restful sleep, without plunging you into the deep stage 4 \"slow-wave\" sleep. That way you can wake quickly without being burdened by \"sleep inertia\", which is that groggy feeling you get after being woken from a deep sleep. A half-hour ... | [
"So then...can I see your source on that?"
] | [
"Then how do the polyphasic sleepers do it?"
] |
[
"A question about forces"
] | [
false
] | So forces are the exchange of gauge bosons. But where do quantum fields fit into this idea? | [
"In our present understanding, quantum fields are the fundamental concept. The existence of quantum fields leads to the existence of particles such as gauge bosons, as well as to other kinds of physical entities (e.g. bound states and extended field configurations like solitons)."
] | [
"Gauge bosons are a means by which the field generated by one object is felt by another. To go beyond such a vague statement requires getting into the actual technical structure of quantum field theory."
] | [
"My understanding is that interactions are essentially transmition of data across a field - what does this mean for gauge bosons?"
] |
[
"Where did early organisms get their energy if there were no other organisms to digest and no photosynthesis?"
] | [
false
] | In a closed system, life couldn't exist on earth because there would be no energy input. However, with the sun giving off energy, it's possible. Animals eat other animals which ate plants which used photosynthesis to get energy from the sun. But what happened before photosynthesis evolved? For even a single celled organism to divide, it needs energy. Absorbing another organism might make sense, but that organism would have needed to find energy as well. Aren't even nutrients full of potential chemical energy that had to come from somewhere? | [
"I'm not entirely sure of the evolutionary progress from single cell to photosynthesis and what was consumed in the meantime. However, there are organisms currently on the planet that do not photosynthesize or consume others. There are a number of different types of ",
"autotrophs that produce food through chemos... | [
"Hello, geology graduate student currently researching habitability on Mars.",
"The answer to your question is chemotrophy. At oceanic spreading centers, specifically on off-axis hydrothermal vent systems called black smokers, there are colonies of multicellular organisms that live without any photosynthetic ener... | [
"One prominent candidate for the cradle of life on earth is these underwater vents - these environments are very stable, even in an age where earth is being bombarded with meteors, they have a ready supply of nutrients and energy that can be accessed relatively easily, and when you look at the genetics of a whole l... |
[
"About how many atoms could fit in a cell?"
] | [
false
] | Alright, alright. I know cells are all different shapes and sizes, but could you do an average iced cell? A single cell that is in the middle of the sizing chart? Thanks. But I've really been wondering about this. Cells are tiny, but atoms are the smallest things in existence. Now, Im no pro at science, ( still In school), but I REALLY want to know. I also read that about 250 trillion atoms could fit in a two dimensional period on your screen,(Answers.com, don't know of they are correct, so sorry if my info is wrong), so I cant really imagine how many could fit in a cell. Thanks! | [
"There's no \"average size cell\" because there's such a huge range of sizes, but human cell that's about 10",
" kg would contain approximately 100 trillion atoms."
] | [
"Wow! Thank you very much!"
] | [
"atoms are the smallest things in existence",
"Not really. Atoms themselves are made up of a nucleus comprised of relatively tiny protons and neutrons as well as even tinier electrons. Protons and neutrons are made up of even smaller particles called quarks (but since they don't exist in a free state at most co... |
[
"Why does it seem like we can see something better if we can hold it?"
] | [
false
] | null | [
"What do you mean?"
] | [
"Like ok if you see something new yes you can look at it but it doesn't always register in your brain what it is. But if you can hold yes it's more senses you can use to identify it but it seems like you can also see it better too."
] | [
"I'm not sure I understand. Things closer to you are easier to see. Something in your hand is isolated and free of clutter in the background and maybe in that sense could be said to be easier to see. Otherwise I'm not really sure what you're asking."
] |
[
"Why are so many nerve/seizure related drugs used for treating mental illnesses?"
] | [
false
] | Why are so many nerve-related/seizure related drugs used for treating mental illnesses? Examples include, Lamotrigine for bi-polar/mood disorder, Gabapentin for anxiety/panic disorder, Venlafaxine for depression, Duloxetine for depression, etc. | [
"The real reason is \"because some of them help, sometimes, and the rest is immaterial.\" But that's not a very satisfying answer.",
"Anticonvulsants work by altering neurotransmission, like virtually all drugs used in psychiatry. You can't treat the brain without, you know, treating the brain. For instance, carb... | [
"It's more than random luck, but less than predictable. Nearly all neurologic and psychiatric drugs have to clear the hurdles of being able to cross the blood-brain barrier, and do something once they get in. And not all anticonvulsants are popular in psychiatry. For instance, phenytoin (Dilantin) is a very effecti... | [
"All of these drugs are blunt tools for prodding neurotransmitter systems to and fro. They are somewhat hopefully and optimistically named after their intended clinical function, but unsurprisingly have broad clinical effects.",
", ",
", ",
", ",
" are all spurious categories. There are structural and funct... |
[
"If I open a door to an air conditioned room from a warm hallway am I letting warm air in, or letting cold air out?"
] | [
false
] | This is something I've always wondered. I asked but didn't get any responses. | [
"Assuming equal air pressures, both. The air will equilibrate (mix to an even temperature/energy state)."
] | [
"The cold air sinks and hot air rises. The cold air is also denser. So the cold air will push out from lower down and the hot air will push in from up high. Probably a little more cold air will fit in the warm hallway since it's denser."
] | [
"But if the pressure is the same, would that not mean that although the individual particles in the warmer room may have more kinetic energy each, overall both volumes of air would have the same net kinetic energy?",
"If that is the case, then the warmer room should have overall less gas particles, thus resulting... |
[
"Would Mercury's close proximity to the Sun make it rich in heavy and precious metals?"
] | [
false
] | null | [
"I don't know why you use \"would\". It already is rich is heavy and precious metal. ",
"Planets are formed when after the star (read: our sun) form, materials in the area start to condense and merge together. Close to the star, its hot, so only things that condense at high temperature can condense. Hence Mercury... | [
"While it's certainly true that Mercury has a lot of heavier metals; the community hasn't really come to agreement on why. Nebular condensation temperature is important, but that does really explain why Mercury is so different from Venus or Earth. The usual explanation is that Mercury used to have a big, sandy ma... | [
"Also, one should not forget that currently astronomers believe there has been a lot of migration from initial planet formation so the old trope of \"rocky planets closer in, gaseous ones farther out\" is not as strong as once thought."
] |
[
"What phenomenon occurs when a full moon creates an observable circle in the foggy night sky around it?"
] | [
false
] | [deleted] | [
"Without a picture it's hard to be sure, but there are two different phenomena that can cause a ring to appear around the moon:",
"A 22-degree halo",
" can form when high, thin ice clouds are in between you and the moon. The ice crystals refract the light at ",
"a specific angle",
" (around 22 degrees) sinc... | [
"Saw a moon dog the other night. It was pretty mild evening here in the desert. Was wondering if dust could cause such things in addition to ice crystals. "
] | [
"Thank you for your reply and photos. I believe it was a 22-Degree Halo in the sky last night. Your picture matched what I was seeing and now I know what to describe it as. "
] |
[
"When others use the English language, I find some accents to be friendly, impressive, sexy, warming; or in other words, superior. I also find other accents to be threatening, cold, unimpressive; or to be inferior. Why?"
] | [
false
] | [deleted] | [
"This is more linguistics than anthropology.",
"Linguists often study these sorts of language attitudes by using what are called matched-guise tests: they record a single speaker and present utterances to raters as if they were coming from two different speakers. Some of these studies, like ",
"Bilaniuk 2003",
... | [
"I don't have much to add to ",
"/u/rusoved",
"'s comment beyond if you want further reading, check out the book ",
", available ",
"here",
". The two applicable chapters are \"Italian is Beautiful and German is Ugly\" and \"They Speak Really Bad English Down South and in New York City\". The basic gist o... | [
"In addition there was an experiment by John Baugh of Stanford where he tried to rent an apartment using several different accents. He's been doing this experiments for years and it's always similar results: when he calls using an accent that is readily recognizable as being from a minority, the renter is less like... |
[
"How does a Belousov-Zhabotinsky reaction work?"
] | [
false
] | I understand it has something to do with being 'auto-catalytic' but the explanation I was given was a bit vague. Also, how does it not violate the 2nd law of thermodynamics? | [
"It doesn't violate any laws because the oscillation dampens over time. After a short while, the reaction reaches equilibrium and stops making pretty colors. The kinetics of the reactions dictate that it must oscillate on its way to equilibrium. "
] | [
"This page",
" has a good explanation of how oscillating reactions happen in general. It's a royal pain in the ass to use, but if you want to see the kinetics run their progress with a plot of different concentrations with time, a program called ",
"Kinsim",
" can simulate it for you if you feed it a set of ... | [
"Do you know any more about the actual kinetics if the reaction? Why exactly dies the oscillation occur?"
] |
[
"Why is carbon dioxide used in fizzy drinks and not another gas?"
] | [
false
] | Why not use nitrogen which is a more abundant or another gas? | [
"A big reason is solubility. CO2 is soluble in 10 degree C water up to about 2.5 g per liter. Nitrogen is only soluble to 0.025 g per liter under those conditions. Oxygen for instance is at 0.055 g per liter.",
"Some gases are higher, but you don't want to drink them - ammonia can reach 700 g per liter, chlorine ... | [
"The dangerous thing about liquid nitrogen under normal circumstances is just its very low temperature and its effective heat capacity due to the liquid->gas transition. It’s used as a way to freeze things very rapidly. Unless the resulting thing is cold/large/conductive enough to give you a frost burn on contact a... | [
"Most gases dissolve in water, but CO2 is special in that it doesn't just dissolve, it ",
" with water to form carbonate and bicarbonate ions and hydrogen ions:",
"H2O + CO2 <==> HCO3- + H+ <==> CO3-- + 2 H+",
"This does two things. First, it \"clears away\" the CO2, allowing even more to dissolve in. As a ... |
[
"Did I Get Electrocuted?"
] | [
false
] | null | [
"Where should i post this then, cause I'd like to know what may have happened."
] | [
"Where should i post this then, cause I'd like to know what may have happened."
] | [
"OK thanks"
] |
[
"What is the biological and/or evolutionary purpose of balding? If there is none, why hasn't it been weeded out by now?"
] | [
false
] | [deleted] | [
"Traits aren't put there because they are evolutionarily favorable. It's more that traits are taken away because they are evolutionarily unfavorable.",
"There isn't really a selection pressure against bald people - they're still good for surviving and mating and raising kids and such - so there's no reason why b... | [
"It's more that traits are taken away because they are evolutionarily unfavorable.",
"Which is another way of saying that traits which ",
" unfavorable aren't taken away."
] | [
"If it doesn't lead to you dying, it will most likely stay there."
] |
[
"Since birds are dinosaurs, are birds reptiles?"
] | [
false
] | null | [
"Yes, from a taxonomic standpoint, birds are reptiles. When we classify animals today we base their relationships on a shared evolutionary history. The taxa we name must consist of a common ancestor and all of the descendants of that common ancestor. It's called a monophyletic group. Any other type of group is arbi... | [
"Reptile is not really associated with an entire clade. The taxon you're actually looking for is ",
"sauropsida",
", which includes reptiles and birds.",
"Reptile",
" is more of an English language word than a proper scientific term because it is not truly associated with a ",
"clade",
" or ",
"taxon"... | [
"I do want to point out that for quite some time now there ",
"has been the argument in paleontology that all nomenclature should be based on phylogeny",
" and as a result of that ",
"there do exist",
" true ",
"phylogenetic definitions of Reptilia",
" which include birds, although it's often pretty clo... |
[
"Would a plant live forever under perfect conditions?"
] | [
false
] | As in, if a plant lived in an environment that had infinite nutrients and pollinators along with the perfect quality of soil and atmosphere at all times (as well as free of disease and competition), would it live forever? | [
"There is a large, ongoing debate on what exactly defines cellular aging. So a plant made of living cells, like every other living organism based on cell theory, may or may not live indefinitely given completely ideal situations depending on your stance in that debate.",
"Several theories exist in what cellular a... | [
"Of any \"plants\" that would survive in perfect conditions I think woody tissue plants would have the best shot. Their structure and internal functions are largely carried our through already dead cells i.e. the heartwood. The living parts of the tree turnover rather quickly, and get replenished all the time. W... | [
"Anything that reproduces via clonal colonies like a grass or moss would have the best shot."
] |
[
"How high can a fly fly?"
] | [
false
] | Up in the air, in nice weather. | [
"You want ",
"this",
" ",
"Basically it has to do with the temperature of the air, needs to be at least 50° for most of them to fly. Not unreasonable to find them over 3k feet, and that's not even taking into account the wind hitchhikers; which have been spotted up 6k feet. ",
"Edit:\nAs ",
"/u/heanster",... | [
"How was a fly 'spotted' at 6k feet? Who saw it, how did they know it was there?"
] | [
"As an avid hang glider pilot, I've never spotted a fly while flying, but I have seen butterflies numerous times at 4-5k MSL. I suspect they get caught in thermal updrafts and can't get out before they've climbed a few thousand feet."
] |
[
"Why do we need sleep?"
] | [
false
] | Are there biological processes in the brain that only occur while in REM sleep? Do our cells need "breaks"? Is it like the importance of rebooting a computer? What is keeping us from always being awake? | [
"From what I've read, your brain needs time to compartmentalize and go over the events of the day--a PC doesn't learn from its surroundings so it doesn't really NEED a reboot so it's not the same. If people are awake more than a certain amount of time, they become delirious--so this need to analyze information is w... | [
"There are also certain hormones for things like growth and tissue repair that are released in higher amounts during sleep. In addition, while you're sleeping your body can create and store energy for future use as not as much is being used as compared to when you are awake and performing various activities of dail... | [
"Your brain spends energy growing new connections (synapses, which equals more axon terminal branches, or maybe even dendrite branches?)\nduring sleep. This forms and/or reinforces memories.",
"I cannot confidently say that this is the ONLY thing sleep achieves. But I am certain that this is true. Those who ar... |
[
"To make tea, I boil water in a glass kettle on a glass stove top. My roommate insisted I put a metal ring between the kettle and the stove so it doesn't crack. Is it really necessary?"
] | [
false
] | null | [
"I'll assume this is an electric stove (of course, in a gas stove a spacer won't make too much of a difference).",
"I'm really surprised at that suggestion. To me anyways, the metal ",
" actually limits the area by which heating can occur, so it is actually promoting uneven and localized heating, which increase... | [
"... it is somewhat sad that this is not obvious.",
"I was in the process of making pickles."
] | [
"gah, don't pour water in a heated pyrex vessel either, heat it as one unit."
] |
[
"Why do steroid hormones such as Testosterone and Cortisol suppress the immune system?"
] | [
false
] | I was reading a book and a chapter of which talks a bit about the mystery surrounding the evolution of steroid hormones such at those in the title and why they suppress our immune systems i.e. what is the evolutionary trade off for that effect? Bearing in mind the book was written in the 90s I wonder if this question now has some satisfactory answers, thanks! | [
"First: steroid hormones are a large class of hormones with widely different effects. Even look at the two you named. Testosterone is a sex hormone involved in reproduction, while cortisol is a glucocorticoid, involved in energy regulation and stress responses. Weirdly enough, high levels of either can suppress the... | [
"Well, the body needs to know when to stop an inflammatory response, i.e. once the white blood cells are finished doing their dirty work. These chemicals are released as an all-clear. And when they're introduced artificially to the body, that all-clear signal is given when there is still a danger to the body."
] | [
"Are you sure testoserone suppress it? I thought it was the contrary"
] |
[
"How does your brain determine if a sound is coming from behind or in front of you?"
] | [
false
] | Wouldn't you need a third ear for your brain to triangulate a sound and figure out for certain whether it was in front of you or behind you...? How does your brain determine that a sound is coming from behind? | [
"For localising sounds, your brain uses a number of cues. Front/back (and elevation) decisions are usually made by exploiting ",
"spectral notches",
". In normal-person language, your head and outer ear is not symmetrical front to back. This means that certain sound frequencies will be more or less dampened by ... | [
"My answer to a ",
"previous question",
":",
"The way the sound interacts with your head and ears causes some frequencies to be emphasized and others to be attenuated. Since your head and ears are not symmetric front-to-back that effect is different depending on whether the sound came from in front of or behi... | [
"Firstly, check out ",
"this",
" link to follow the anatomy in my description if you like.",
"The inferior colliculus in actually already fairly high in terms of this type of processing. The inputs from the two ears (via the cochlea and audtiory nerve) first enter the brain in the auditory brainstem, located ... |
[
"Are children born with a language acquisition device etched in the human brain or is it developed by hearing language."
] | [
false
] | In other words, languages have common rules, if a baby was raised in solitude would they develop their own sense of language with the same rules. i.e. Nouns are things you can point at, and verbs are what they are doing simple rules like that. | [
"You are not including sign language acquisition by deaf babies or hearing babies with deaf parents. ",
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1868823/"
] | [
"if a baby was raised in solitude would they develop their own sense of language with the same rules.",
"Probably not, we know this based on children who were not exposed to language during a critical period such as Genie the feral child and other feral children. Some of them are more functional than others and t... | [
"That's... not the way it works. People obviously don't do this voluntarily - children all around the world can be born deaf and grow up in a family that does not know a sign language. So the child develops his or her own language and the parents learn it. "
] |
[
"How come the majority of people in the world are right-handed?"
] | [
false
] | Was there an evolutionary advantage to having your right hand as your dominant? | [
"To add to the current answer a little bit and address the question in your title, the majority of the world is right-handed due to genetics with some influence of culture. There is a lot of really interesting research out there trying to predict hand dominance early in life. Some people have done studies where the... | [
"I'm not sure that there is conclusive evidence, but the most probable theory I've read is that it's linked to the specialization of brain hemispheres (which in turn is believed to be advantageous for species of higher intelligence - this of course just shifts the problem to the question why our brain is wired as-i... | [
"Has anyone looked at direct cultural ties to left or right handedness? I had temporarily lost the use of my right hand over a medical condition, and came to the realization of how much easier people that are right handed have it when I was learning to write with my left hand. In English, right handers drag away fr... |
[
"What effect does the arctic summer sun have on plant life?"
] | [
false
] | As illustrated by , the arctic summer sun doesn't set. Does the constant sunlight have any effect on plants in that area? In an unrelated question, how productive would a field of solar panels be under this sun? Would the panels produce a lot more energy than elsewhere in the world? | [
"In theory, it would certainly help plants grow. In reality, though, it has very little effect, because the limiting factor of plants in the arctic is nutrient availability. The soil there has a layer of permafrost that prevents anything big and vascular from growing. It's why most plants in the arctic are low-g... | [
"Hey thanks, that's definitely something I didn't think of. How well would a greenhouse work then? If you brought in nutrient-rich soil, would a greenhouse be amazing? This is probably an economics question, but I wonder if the increased sunlight and reduction in artificial lighting would offset the extra heating... | [
"In theory, a greenhouse should thrive in the arctic. I'm sure it's been done before. But, it would have to be extremely well maintained because if it were to be self-sustaining it'd only be so for a short time in the year, then increased energy costs during the other 6-8 months would likely make the greenhouse i... |
[
"Is there a material that is the equivalent of a superconductor, but for light instead of electricity?"
] | [
false
] | I understand that there are "superconducting" materials which can achieve an electrical resistance of zero ohms - is there a similar material or class of materials (not a vacuum) that can achieve a zero attenuation for light or other EM wavelengths? | [
"Not a physicist, hence: wouldn't \"a vacuum\" essentially be OP's answer? Notwithstanding that it's not technically a material."
] | [
"All materials (that are currently known) have tiny resistances in the absorption and emission of photons. This GIF is a good reference - ",
"http://www.physicsclassroom.com/mmedia/waves/em.gif",
" - which unfortunately means that any EM wave travelling through a medium will be slowed. ",
"If such a \"superco... | [
"You're confusing resistance and joule losses with signal velocity, or alternatively absorption with phase velocity. ",
"A superconductor has zero resistance, that says nothing about delaying or slowing a signal. It's resistance and therefore energy loss is zero, but it's reactance can be any value and it's sign... |
[
"Is there another type of electromagnetic radiation past gamma radiation?"
] | [
false
] | Is there anything with a shorter wavelength than gamma radiation? | [
"No. ",
"Gamma rays",
" are, by definition, electromagnetic radiation with wavelengths shorter than 1 picometer (10",
" m, one trillionth of a meter). For some purposes they are broken down into subcategories like ",
"very-high-energy gamma",
" and ",
"ultra-high-energy gamma",
", but these are really... | [
"Just wondering"
] | [
"Even for visible light, the precise border is a bit arbitrary, because human vision doesn't magically stop at a precise wavelength - it just gets weaker the more you get into the infrared / ultraviolet until the intensity needed to see something gets unreasonable."
] |
[
"How does DNA change over the course of our lives?"
] | [
false
] | Does DNA change due to life experiences? Could my child be genetically better at handling certain things I’ve had to handle in life? | [
"DNA methylation is incredibly stable. It is fun to think about changes in an epigenetic state resulting in some heritable change with their offspring, but I would caution thinking about this differently than a simple change in the sequence of DNA. So while we expect to so pre-programmed changes in methylation and ... | [
"DNA methylation is incredibly stable. It is fun to think about changes in an epigenetic state resulting in some heritable change with their offspring, but I would caution thinking about this differently than a simple change in the sequence of DNA. So while we expect to so pre-programmed changes in methylation and ... | [
"DNA does change, but mostly at very slow, random rates (vast oversimplification here) rather than in response to life experiences. That said, as others have mentioned, while the genome isn't changing significantly between generations based on life experiences, the epigenome can and does. We don't have perfect id... |
[
"If a human needs 2000 calories per day, could a human be said to run on 96 watts?"
] | [
false
] | 2000 kilocalories = 8360000 joules 1 day = 86400 seconds 8360000 joules/86400 seconds = 96 watts I have to be doing something wrong here. We don't require on average less than a lightbulb, do we? | [
"Surprising as that may sound, you are right, the ballpark power expenditure of humans is roughly that of a 100W light-bulb running constantly. If that sounds surprising, keep in mind that incandescent lightbulbs are extremely inefficient, with less than five percent of the energy put in being converted to visible ... | [
"He didn't claim they are the most efficient, but that they are significantly more efficient compared to incandescent lights."
] | [
"He didn't claim they are the most efficient, but that they are significantly more efficient compared to incandescent lights."
] |
[
"Can someone die from an adrenaline rush induced by the body ?"
] | [
false
] | If someone finds themselves in an intensely stressful situation, one necessitating a fight-or-flight response for example, the body releases adrenaline. Can the body release too much of it, as in a lethal dose ? | [
"Pheochromocytoma",
"A condition where excessive adrenaline is excreted is called pheochromocytoma. ",
"Many cardiac manifestations are associated with pheochromocytomas. [26] Hypertension is the most common complication. Cardiac arrhythmias, such as atrial and ventricular fibrillation, may occur because of ex... | [
"Catecholamine wash of the body can occur for many reasons. Yes one can die. And do. That's why anesthesiologists have better outcomes if talking to the patient the night before surgery as opposed to as they go into the operating room."
] | [
"Indeed. Isnt this similar to being \"scared to death\"? As in you have a situation so scary that it releases a large enough amount of adrenaline that could kill you?"
] |
[
"Do bugs feel pain?"
] | [
false
] | Speaks for itself, do bugs feel pain. and if they do, is it relative to the way human beings do? | [
"There is pain and there is nociception. They are related, but distinct.",
"Nociception, the simpler of the two, is the detection of damage or injury. Pretty much all multicellular organisms feel it in some way or another. You could argue that microorganisms feel it as well in a different form.",
"Pain is an un... | [
"https://pay.reddit.com/r/askscience/comments/qsemo/do_insects_feel_pain/"
] | [
"Absolutely bugs feel pain. Insects actually have surprisingly sophisticated central and peripheral nervous systems that are comprised of neurons very similar to our own. ",
"Now, there is no way to know how they actually experience it, just as there is no way to know if your experience of pain is the same as min... |
[
"Is there a physical limit to the size of a black hole? If conditions were right, could it continue to draw in matter?"
] | [
false
] | Barring any catastrophic collisions or explosions from nearby novas, is there a limit to how large a black hole can get? | [
"I've got no idea what that other guy is talking about.",
"Black holes can and do continue to get larger as they absorb more matter and energy. Additionally, no known force can destroy a black hole except maybe hawking radiation, and that would take trillions of trillions of years.",
"Even if you had a supernov... | [
"No, there's no limit. If you keep throwing mass into a black hole it just keeps getting bigger."
] | [
"So even if, say, two supermassive black holes collided, it wouldn't get bigger? I have been led to believe that the intense gravity pulls all nearby matter into it, slowly growing. Or does that not increase the size, it's only dependant on the size of the star it formed from?"
] |
[
"Why does the universe not have a \"center\" and \"edges\"?"
] | [
false
] | If the universe started at a single point and its space fabric expanded in all directions, at a velocity no greater than c, why does it not have a definite volume? why is there no specific point of origin? Why is there not a current frontier of space, instead of a radius of 14 billion LY of observable universe at every point in existence, which implies that the universe has no limits? | [
"I like this answer from Harvard:",
"\nNo. The Big Bang was not an explosion IN space. It was a process that involved ALL of space. This misconception causes more confusion than any other in cosmology. Unfortunately, many students, teachers, and scientists(!) mistakenly picture the \"Big Bang\" as an explosion th... | [
"It's just really hard to understand that space itself is something. ( atleast for me)"
] | [
"Most people find quantum mechanics incredibly confusing and impossible to understand, and yet it's one of the most verified models we have ever created. Our own abilities have nothing to do with validity. "
] |
[
"Are molecular ' daisy chains' possible?"
] | [
false
] | For instance, could a bunch of benzene rings be linked through each other into a sort of pseduo-polymer - or is there just not enough space in the centre? A couple of other questions in the same vein: Is it possible for two crystals to be constructed through the gaps in each other's structure - locked but not actually bonded? Can organic polymers be bent into rings? | [
"So there is an area of chemistry very much related to your question. It's called ",
"Supramolecular Chemistry",
".",
"\nSo as already mentioned benzene rings are too small and have too much electron density to be able to interlink. However with larger rings it is possible, and this class of compounds are cal... | [
"Sure, though you need fairly big organic molecules to get non-bonding connectivity. Benzene rings are too small and too electron dense to allow any bonding through their center but you can do things like make mechanically cross-linked polymer systems where one material is locked into place \"inside\" another.",
... | [
"That... is ridiculously awesome. Thanks!"
] |
[
"In the movie Gravity when Sandra Bullock is spinning out of control, would simply closing her eyes stop the spinning sensation?"
] | [
false
] | null | [
"Yes, kind of. But only after she stops flailing and waits a few seconds.",
"Rigid objects with no external forces acting on them ",
" will inherently* only spin about a single axis at a constant speed, so all that appendage-flailing changing her moment of inertia and center of mass has to stop. When she holds ... | [
"Wouldn't you have the sensation of centripetal forces acting on you? Those forces would want to pull your arms and legs and legs out unless you're only spinning end over end."
] | [
"If you are spinning fast definitely! If you spin even faster you can pass out or even die!",
"The red bull guy doing a high altitude jump almost died due to passing out during a spin in free fall!"
] |
[
"When burning fat, what exactly is preventing a person from entering ketoacidosis?"
] | [
false
] | So I'm just trying to make sure that I understand this properly. From what I gather type I diabetics are at great risk for entering ketoacidosis because fatty acids are being broken down, releasing ketone bodies into the blood. If a person loses weight and burns a lot of the stored fatty acids in their body, what exactly is preventing them from acquiring ketoacidosis from the fatty acid breakdown? | [
"The reason people go into ketoacidosis isn't just that there is a breakdown of fat into fatty acids. It's that (classically speaking) in a type 1 diabetic they have an absence of insulin. What happens is that in the absence of insulin, hormone sensitive lipase breaks down fat into fatty acids that then build up in... | [
"Individuals with diabetes type I have absolute insulin deficiency (they do not produce insulin) and therefore this lack of insulin tricks the body into think that it cannot utilize glucose in the body. The body then breaks down other sources ( ex- protein and fats) to generate energy. The break down of fatty acids... | [
"There should really be a requirement that anyone with a question must check wikipedia first.",
"In healthy individuals, the pancreas releases insulin to slow ketone production before the ketone concentration in the blood gets too high. Diabetics cannot produce sufficient insulin, so they can't slow ketone produ... |
[
"How much land does it take to support one human being?"
] | [
false
] | How big does my plot have to be before I can support myself with vegetables and fruit? I live in the UK, so temporate and usually more than adequate rain. | [
"The minimum amount of agricultural land necessary for sustainable food security, with a diversified diet similar to those of North America and Western Europe (hence including meat), is 0.5 of a hectare per person. This does not allow for any land degradation such as soil erosion, and it assumes adequate water supp... | [
"Well, you can only go so far with vertical gardens because yield is limited by light input. Those squash won't grow as well in the shade of tomatoes."
] | [
"Well, you can only go so far with vertical gardens because yield is limited by light input. Those squash won't grow as well in the shade of tomatoes."
] |
[
"Why does oil shine in all rainbows colours when it is in contact with water like rain?"
] | [
false
] | [deleted] | [
"It forms a very thin surface layer on the water. It's so thin that its thickness is in the order of magnitude of the wavelength of visible light. That in turn allows for interference between light reflected on the oil/air boundary with light reflected at the oil/water boundary. What wavelength constructively inter... | [
"It happens when the film of oil/gas has a thickness close enough to the wavelength of light where the reflected beam can cause interference with the entering beam.",
"This i because two different substances with differing refractive indexes cause part of the light to reflect where the two meet and because light ... | [
"https://www.reddit.com/r/askscience/comments/tflhw/what_causes_the_rainbowy_look_in_oil_that_has/",
" - 7yr",
"https://www.reddit.com/r/askscience/comments/1idrfn/why_are_oil_leak_rainbows_the_way_they_are/",
" - 6yr",
"https://www.reddit.com/r/askscience/comments/1a41uf/why_does_a_puddle_of_oil_look_like_... |
[
"How many people do you have to have in a room before you can be certain that their birthdays cover all 365 days of the year?"
] | [
false
] | null | [
"Thank you for your submission! Unfortunately, your submission has been removed for the following reason(s):",
"/r/AskScience",
"To check for previous similar posts, please use the subreddit search on the right, or Google site:reddit.com",
"/r/askscience",
" ",
"Also consider looking at ",
"our FAQ",
... | [
"Hi! Perhaps my google-fu is not strong, but I couldn't find an answer to this particular problem on google, Wikipedia, or ",
"r/AskScience",
". ",
"The are a couple of common problems that are similar. The most common one is the \"Birthday Problem\", the resolution of which is that if you have 23 people in a... | [
"I believe what you're looking for is on the birthday problem wiki. There's a section that discusses p(n) and p-bar(n) where p-bar(n) is the probability that all n birthdays are different. I think that's what you're asking for, no?"
] |
[
"Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science"
] | [
false
] | Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...". Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists. Please only answer a posted question if you are an expert in the field. . In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for . If you would like to become a member of the AskScience panel, . Past AskAnythingWednesday posts . Ask away! | [
"I do not think so. For example, Venus is almost the same size as Earth, but its Karman line equivalent would be ",
"around 250km",
". It depends on a planet's atmospheric properties, which is a confluence of factors including its orbit, elemental composition, etc."
] | [
"Assuming the laws are physics are broken, what do the laws of physics tell us then? \nDo you see the problem? You can't just assume that the laws are broken and the see what the laws are telling us."
] | [
"First, this is an ask anything thread. ",
"yes, and I don't want to criticise you for asking something. Not at all. But you started your question with: \" assume that time travel is possible\"",
"This assumption immediately breaks physics. So I have to criticise your question. ",
"We also don’t know if quant... |
[
"Where do squirrels go during hurricanes?"
] | [
false
] | null | [
"Squirrels nest in hollow trees or in bird-like nests that are larger. In weather, if they feel the need to shelter, they seek anything available that qualifies as an umbrella. Hollow trees are your best bet for finding them sheltering. They will also readily use barns and houses if humans do not disturb them."
] | [
"They lived in the wall in a place I was renting. I was living in a pretty wooded area so they were everywhere. I never told the landlord...they were my super secret squirrel friends..."
] | [
"Is this where they typically sleep? Or is this just in extenuating circumstances like extreme weather?"
] |
[
"Violet in photographs?"
] | [
false
] | Every diagram I see of the visible spectrum includes violet next to blue. However every photograph I see of refracted light fades to black instead of violet. Is this simply because the RGB filter on a digital camera does not capture violet light, while our eyes do? Or am I just not looking at enough pictures to find a counter example. | [
"This photograph has a purplish bit at the end.",
" I suspect you just weren't looking at very good photographs. Filters may have been an issue, although these days digital SLR cameras are capable of capturing ",
"both ultraviolet and near infrared",
".",
"Interesting note on \"Indigo\": Isaac Newton was th... | [
"Let me help you out with a picture of a rainbow where you see violet :-)\n",
"http://www.flickr.com/photos/charlestilford/189639434/",
"So it appears to be not a general problem. Maybe in special cases where the spectrum of the source is limited ...."
] | [
"In which medium are you looking at the photographs? Depending on how it is presented (for example a printed magazine vs. a computer screen), reproduction of certain colors can be impossible without spot inks. If it is a digital image you are looking at, provide a link to the example."
] |
[
"What's the cheaper source of energy, electricity or food?"
] | [
false
] | ethics aside if i have a man tied up is he going to raise the room temperature higher per 1$ of food, compared to a space heater with 1$ of electricity? | [
"Electricity costs on average about $0.10/kW-hr, so $1 would buy you 10 kW-hr, or 36 MJ. For comparison, a McDonald's double cheeseburger costs a dollar and has 390 Calories, or 1.6 MJ. Odds are, a normal food won't be our best bet.",
"A sorta-food option could be cooking lard, which is pure fat. A jar of Crisco... | [
"If you intend to feed you captive with lobster and caviar, it would probably be cheaper to plug in a space heater. ",
"1 kWh = 3600 kJ, fat contains 37 kJ/g, if (3600/37=)97.3 grams of fat is cheaper than 1 kWh electricity at your location, it might work. ",
"As an alternative scenario, may I suggest yo... | [
"But that's not entirely fair because the electricity is essentially being mass produced and sold at a price adjusted by the government. Crisco is a name brand, trying to squeeze as much money as they can for their product and not producing at the same scale.",
"I wouldn't be surprised if you could produce your o... |
[
"Are there any substances that significantly help reduce the negative effect of sodium on blood pressure?"
] | [
false
] | null | [
"do you want studies or articles?",
"meta-analysis:",
"http://www.ncbi.nlm.nih.gov/pubmed/9168293",
"article:",
"http://www.livestrong.com/article/29315-potassium-lower-blood-pressure/"
] | [
"basically, with the way the kidneys work, the more potassium you have in your blood, the more sodium is excreted in urine. "
] | [
"It is true that potassium has the opposite effect on blood pressure as sodium. It is also true that most people don't consume enough potassium.",
"eat more potassium."
] |
[
"Have serial killers always existed?"
] | [
false
] | Like in for example the middle ages, were there sick people that killed others for fun then? How about much much earlier? | [
"Try ",
"/r/asksocialscience",
" for this."
] | [
"In the middle ages, there was (probably) Gilles de Rais. He was a noble, and serial murderers who were commoners killing people in a village somewhere wouldn't have made the history books."
] | [
"Homosexuality was actually quite taboo in old Norse culture. Vikings certainly weren't raping monks in front of each other.",
"That aside, the Viking age was precipitated by a cooling period combined with pressure revolving around the Church. First, farming in Scandinavia became more difficult. The Church had... |
[
"Does the pocket of air displaced around a fast moving vehicle affect the sound we hear via the Doppler effect?"
] | [
false
] | I came up with this question last night after an ambulance sped by my apartment. | [
"Short answer: yes. Long answer: only matters if you're a mathematician or searching for perfection. The compression of air for objects below about 370km/h (103m/s, 240mph, 0.3 Mach) is less than 5%, so the predominate cause of the frequency shift will be the Doppler Effect.\n",
"https://www.wikipedia.org/wiki/Co... | [
"I was just watching Top Gear as a Bugatti test driver got the Veyron SS to ~263mph; probably not enough over that 240mph threshold to matter much....?"
] | [
"i know how the Doppler effect works; i'm specifically asking is it/how is it affected."
] |
[
"What speed does gravity propagate at?"
] | [
false
] | null | [
"See the FAQ"
] | [
"I had a brief look, and I couldn't see the question I was looking for. Could you point me in the right direction?"
] | [
"It's under the astronomy section:",
"https://www.reddit.com/r/askscience/comments/1kjp6z/does_gravity_travel_at_the_speed_of_light_if_the/cbpmm9a/"
] |
[
"Could you get ripped by consciously flexing your muscles for the majority of your day?"
] | [
false
] | I sometimes try to flex my core to help with back spasms and it seems to help. | [
"Possible to get ripped? No. Possible to make the muscle more stable? yes. ",
"The \"ripped\" look is caused by (among other things) hypertrophy of the muscular cells. The actual cause of this change is unknown, but is hypothesized to be in part a reaction to the soreness (and hence the microtears/DOMs) caused by... | [
"I replied in the thread if you would like to read it :)"
] | [
"Technically, I think you could.",
"I've tried this. It's... exhausting, and there seems to be some sort of fail mechanism in your body that makes you tired, bored, and want to stop. Also, it's embarrassing. In the end, it's probably more effort than going to the gym and I think there might be a risk of stroke, h... |
[
"Does fluoride in tap water really have any noticeable effect on houseplants?"
] | [
false
] | null | [
"Yes and no..\n depends on the plant... or more particularly the root zone. ",
"If you are trying to grow organic vegetables for instamce the floride can effect the microbes in the root zone that help with nutrient exchange... ",
"If you are throwing miracle grow in a planter for flowers its probably not a big ... | [
"I'd honestly worry about the chlorine long before the flourine in most cases (but maybe that's because I keep aquariums), although obviously you can keep ordinary houseplants using standard tap water(or else they would hardly be popular houseplants)"
] | [
"Not as house plants, but i have an organic garden and i only use stored rainwater."
] |
[
"About collisions on the Moon."
] | [
false
] | After watching video, I was wondering why hasn't there been any major collisions that we have observed? Is it just because there aren't many objects traveling in the orbit of the earth/moon? Sorry for any confusion or errors. | [
"It's because there just isn't as much loose stuff floating around the Solar System these days. Likewise, we haven't had any major impacts on Earth in a long time, and the Earth is much larger and more massive and therefore more prone to being impacted. The largest meteorite impact since the invention of the telesc... | [
"I like this answer but I want to give one nitpicky correction: There are plenty of large things floating around in the asteroid belt. However, they are in stable orbits and in recent history nothing has perturbed those stable orbits.",
"Also the LHB is hypothesized at this point. "
] | [
"Thanks for the clarification!"
] |
[
"Can you see evidence of the boundary layer on an airplane wing?"
] | [
false
] | I was recently flying and I noticed (although not entirely clear) that the air on the top of the wing seemed distorted, like light going through a prism. Is the difference in density in the boundary layer and surrounding air great enough to refract the air so that the naked eye can see it? Or was I just seeing an optical illusion? | [
"I was recently flying and I noticed (although not entirely clear) that the air on the top of the wing seemed distorted, like light going through a prism. Is the difference in density in the boundary layer and surrounding air great enough to refract the air so that the naked eye can see it? Or was I just seeing an ... | [
"Any real observable effects of the pressure gradient would not come directly from the air itself. Much more likely that you are seeing the end result from the interaction of water particles in the contrail that forms on the plane wing.",
"I don't know whether contrail formation is defined by the boundary layer t... | [
"I was observing this from the front of the wing so I don't know if it would explain this. I might have just been tricked through the window or something, was curious if anyone knew.",
"The contrail effects are due to vorticies at the tips of the wings from the pressure difference on the top and bottom of the win... |
[
"[Neuroscience] What is the difference between anticholinergics and antihistamines?"
] | [
false
] | Both of them seem to be described similarly, and I have heard people use them interchangeably. I found one source stating that antihistamines such as dyphenhydramine produce anticholinergic effects. If that is true, then why wouldn't it be classified as a histamine antagonist? Is the histamine system a subsystem to acetylcholine like the nicotinic receptors and muscaric receptors? I'm very confused. Are the histamine and acetylcholine even related at all? | [
"The simple answer is that mACh-receptors and histamine1-receptors look fairly similar to each other which allows for a lot of cross-reactivity. First-gen anti-histamines like diphenhydramine (which cross the blood brain barrier) are primarily anti-histamines (edit for clarification: histamine1-receptor antagonists... | [
"Thanks, this answers a lot of questions for me."
] | [
"one thing that is critical to understand is that no drug is 'truly' specific for a certain receptor, or even receptor subtype. This goes for anything really, if you saturate a system with enough of a compound it will eventually start binding to non-specific receptors (in other words, it has lower affinity for the... |
[
"Why is it that we literally feel \"heartbroken\" (physical pain in chest area) when we get sad? What is going on?"
] | [
false
] | Would love to hear about the chemical, neurological, physiological, and/or any other basises for this phenomenon. | [
"The vagus nerve, which is the main nerve connection between the brain and our internal organs, has a lot to do with it:",
"Excessive activation of the vagal nerve during emotional stress, which is a parasympathetic overcompensation of a strong sympathetic nervous system response associated with stress, can also ... | [
"Don't forget, being \"heartbroken\" can lead to ",
"takotsubo's cardiomyopathy",
", which is incredibly interesting. Perhaps a cardiologist could shed some light on it other than just wikipedia."
] | [
"I'm pretty sure chest pain's a symptom of vasoconstrictors, and vasodialators relieve angina.",
"Vagus is parasympathetic BTW, rest n' digest. "
] |
[
"Is there a relation between the amplitude and the frequency of electromagnetic waves?"
] | [
false
] | From what I know the energy of electromagnetic waves, or any waves for that matter, is quadratically dependent on their amplitude. That amplitude is dependent on the amount of photons the wave consists of, making it quantised. On the other hand, according to the Planck-Einstein equation E=hf, or the energy is linearly dependent on the frequency of the wave. Does this mean that the amplitude and the frequency of any specific electromagnetic wave are related? This doesn't seem to make much sense, as they should be independent. Or am I just misinterpreting this and does the Planck-Einstein equation just tell us how many photons of any specific wavelength are produced by a black body? Apologies in advance if this is a remarkably stupid question :) | [
"No there is not. The amplitude can be thought of as the number of photons that make up a wave (although it is a bit more complicated than that), each with their own energy."
] | [
"Thanks for the answer. Now if you look at an EM wave consisting of just one photon, the energy in this wave depends quadratically on its amplitude, or E~Ampl². But the energy according to planck/einstein is purely dependent on its frequency, or E~f. Doesn't this imply that freq ~ Ampl²? And wouldn't this effect th... | [
"Isn't the energy then equivalent to the intensity times the speed of light, making it still dependent on the amplitude of the wave?"
] |
[
"The Universe is expanding, but what into?"
] | [
false
] | null | [
"It is largely accepted that the Universe is expanding, but what is it expanding into?",
"It's not expanding \"into\" anything. The statement \"the universe is expanding\" means \"the distance between any two sufficient distant objects increases in time\".",
"If one found itself at the wall of the Universe coul... | [
"How is it possible for something to be infinite in size though?",
"Why shouldn't it be possible?",
"Sorry, I’m not very familiar with the theory but wouldn’t you run out of matter eventually as even though there would be a large amount there must be a finite amount.",
"Why do you think there must be a finite... | [
"How is it possible for something to be infinite in size though? Sorry, I’m not very familiar with the theory but wouldn’t you run out of matter eventually as even though there would be a large amount there must be a finite amount."
] |
[
"Why are cochlear implants limited to human range of sound?"
] | [
false
] | It seems like it might be able to be extended (i.e. could hear dog whistles, etc.). Is it a limitation with the brain, the technology? Or is it simply to give the recipient "normal" hearing patterns? | [
"Sure, we have the technology to increase the frequency range on cochlear implants, but the reason they aren't is because human communication is done well within the range of normal hearing. Focusing on that range is the most efficient way to use the limited number of electrodes (22) that replace the 16,000 or so h... | [
"I think there is something you are not taking into account. The way to increase the audible range is through the microphone and electronics. Very high-frequencies, say 50 kHz, could be programmed to excite one of the electrodes in the cochlea. As a result you would \"hear\" the 50 kHz sound in the sense that your ... | [
"I think there is something you are not taking into account. The way to increase the audible range is through the microphone and electronics. Very high-frequencies, say 50 kHz, could be programmed to excite one of the electrodes in the cochlea. As a result you would \"hear\" the 50 kHz sound in the sense that your ... |
[
"Do we know of any genes that still produce a protein but its receptor has been lost?"
] | [
false
] | Like the title says, is there any gene that produce a protein that used to bind to a receport, but the receptor has been lost somewere down the line. | [
"Well in bacteria, their sequences could contain genes that they acquired from other bacterial species. So if that gene is active/producing a protein, it's possible that it serves no purpose if that protein only can be used by the bacterial species of origin. Maybe a microbiologist could clarify/correct me"
] | [
"I can't think of one (at least, endogenously), and it wouldn't make sense for something like this to exist from an evolutionary standpoint. The closest thing I can think of is the reverse of what you're asking. This we refer to as ",
"orphan receptors",
". However, it's not that the endogenous ligand isn't pro... | [
"I presume the proposed schedule is:\na) Gene produces protein which is useful & has receptors etc\nb) Something changes so that having that protein active is now actively harmful\nc) Mutation arises that turns the receptor for the protein off\nd) This contextually helpful mutation spreads through the population, l... |
[
"Can I have my DNA sequenced to find out my ancestry?"
] | [
false
] | Is there a place that would do this for a reasonable price? | [
"The Genographic Project",
" will give you information about your ancestors over the last ~70,000 years. Also, you can agree to having your DNA sequence placed (anonymously) in a large database of human sequences."
] | [
"After the Genographic Project I was invited to have more tests run on the original sample they still had (they may still do this for free, I don't know ) by familytreedna. This got me in touch with people I had a certain number of markers in common with, some of whom shared my last name. After finding these peopl... | [
"23andMe",
" may be what you're looking for. Sometimes they offer \"free\" kits with a year-long subscription to their analysis service (of $12/mo)."
] |
[
"Dish soap and bubbles. A common marketing ploy?"
] | [
false
] | Growing up, I've always looked at a sink filled with dish soap, and assume it's good stuff because, well... there's a huge amount of bubbly foam around it. The bubbles mean it's hardworking clean chemicals right? I look at it now, and I think: Why does this foam happen? I use sanitizer solution and this does not occur. Are the bubbles a result of legitimate reaction to the chemicals that work to keep our dishes free of bacteria, or is it just something else put into these products to make people have a visual appreciation? | [
"Sanitizer and soap work very differently. Sanitizer works by either killing the bacteria (like bleach) or removing it directly (like alcohol). Soap works with agitation to trap oil in balls that are soluble in water, and then washes whatever was attached to the oil down with the water. Unlike sanitizers, bacteria ... | [
"Nope.",
"Bleach and alcohol disrupt cells by chemically wrecking their membranes and cell walls. There's not really any way to become resistant to this. Antibiotics are a lot more subtle, affecting specific bacterial enzymes or structural molecules, and so are easier to evade or disrupt.",
"By analogy: it is p... | [
"Bacteria become resistant to bleach and alcohol?"
] |
[
"Why does heat rise?"
] | [
false
] | I know the typical explanation is that as air gets hotter, it expands, thus becoming less dense, and rising. But that only really makes sense if it's trapped in a balloon or something, right? I mean, it's the individual molecules that are hotter, and individual molecules can't become less dense... Or can they? | [
"A higher temperature means that the particles (could be molecules, could be single atoms, etc.) are vibrating more. When you have lots of particles together, making up air, the fact that they vibrate more causes the air to expand, making it less dense, so it rises, as you say. ",
"If you have an individual parti... | [
"The mean free path of molecules in air is < 100nm. This means they don't travel very far without bumping into one another, and generally don't travel very quickly. They're kept in little neighborhoods by the surrounding particles.",
"Therefore, the assumption of treating small patches of volume as continuum fl... | [
"It helps to think of air like a fluid, like water. The oceans have currents because cold, dense water sinks (and there are many of factors but ill ignore those). Likewise cold air is ",
" more dense than warm air so it sinks. This will cause the air to circulate. As far as heat transfer goes, this is convection-... |
[
"Why does it appear that electrons, neutrons, and protons are more common in the universe that positrons, antineutrons, and antiprotons?"
] | [
false
] | Does the universe have equal amount of antimatter as it does matter? | [
"Nobody knows why there is no natural antimatter, but there are some educated guesses.",
"Once upon a time (as recent as the 1960s) many scientists thought that while matter obviously dominates within our region of the universe, there should also be regions of antimatter. This was reasonable because it was produc... | [
"This is currently a mystery."
] | [
"tl:dr; There ",
" more matter than antimatter, we don't know why, lots of smart people are working on it, it may lead to a deeper understanding of the universe.",
"Question two first: \"Does the universe have equal amount of antimatter as it does matter?\"",
"We are very confident that the universe is utterl... |
[
"Would consistently exposing an infant to a foreign language help it with said language later in life?"
] | [
false
] | If I, for instance, played German movies or music to the kid during the day, would he have an easier time learning German, or would it just muddle with him learning English? Would early development be a good time to introduce multiple languages, or would they just get all mixed leaving the kid unable to speak one? | [
"Take out the \"foreign\" part, and this is how every baby in the entire world learns their native language(s). To learn a language you have to be exposed to it. It just takes a lot of exposure over a long time. If a Japanese baby is born in Japan to Japanese parents, but is locked in a room and never hears the ... | [
"I'd agree that's not the most appropriate for this subreddit due to it being anecdotal, as well as a misinterpretation.",
"What goes on in their speech and what goes on in their minds are two very different things. Multilingual babies (even the ones only learning two languages) tend to mix languages for a while... | [
"I'd agree that's not the most appropriate for this subreddit due to it being anecdotal, as well as a misinterpretation.",
"What goes on in their speech and what goes on in their minds are two very different things. Multilingual babies (even the ones only learning two languages) tend to mix languages for a while... |
[
"What is generally used to cool down superconductive elements?"
] | [
false
] | Not just in labs, I'd like to know what is used outside of it because I figure that labs probably use some way that is really effective but also expensive, which is logical, but unuseable in other ways beacuse of the cost, so I'm wondering what it is that does the trick for the outside of the lab use. EDIT: Thanks, I've been wondering for some time so I asked here rather than browse and possibly end up with wrong info. | [
"It will almost always be liquid nitrogen or liquid helium. Liquid nitrogen is the cheapest cryogenic that can cool existing superconductors below the critical temperature. In fact, the development of \"high temperature\" superconductors that can operate above the boiling point of liquid nitrogen (77K) was a godsen... | [
"The basic principle is as follows: compressing things makes them hot, then they naturally cool to room temperature, decompressing them makes them hella cold. It can be useful to store them in their compressed state to save on cost and then to decompress at will.\nEdit: typo"
] | [
"Liquid Helium (LHe) is typically cooled using a system which works much like your air conditioner or refrigerator. The Helium gas is first compressed increasing its temperature. It's then sent through a heat exchanger with some gas that is colder on one side to suck out the heat from your compressed gas and thus l... |
[
"How come (-1)^(2/4) =/= (-1)^(1/2)?"
] | [
false
] | null | [
"Those are equal."
] | [
"You're screwing up the brackets, if you want to do (-1)",
" you have to evaluate what's in the brackets first, if you want to calculate (-1",
" )",
" then you'll get 1."
] | [
"No, (-1)",
" = i",
"(-1)",
" = 1"
] |
[
"How does the human brain determine whether sounds come from in front or behind?"
] | [
false
] | So most people would understand that the reason we have two ears is to determine whether sounds are coming from one side or the other through the time difference each ear receives the sound. How then, does the brain distinguish between sounds in front and behind if the ears are aligned symmetrically? Similarly, you can generally hear whether sounds come from above or below you. | [
"Adding onto this, when it comes to up/down and front/back localization, we are best at localizing high-frequency, complex sounds. By complex, I mean sounds with multiple frequency components like white noise, as opposed to something simple like a pure tone. ",
"The high frequency part comes from the shape of the... | [
"Adding onto this, when it comes to up/down and front/back localization, we are best at localizing high-frequency, complex sounds. By complex, I mean sounds with multiple frequency components like white noise, as opposed to something simple like a pure tone. ",
"The high frequency part comes from the shape of the... | [
"Interesting note: The ",
"facial discs",
" around owl eyes help to funnel sound to the ears. In some owls, ",
"these are offset",
" which allow them to do an even better job of telling exactly where a sound is coming from. This is how they are able to grab a mouse under snow without even seeing it."
] |
[
"How can animals smell things from a large distance?"
] | [
false
] | For example, there's a type of bear that can smell things from 18 miles away. If smells are essentially particles interacting with nerves in your nose, how are the animal's nerves interacting with particles that aren't even nearby? How can an animal smell something that isn't even there by it? | [
"The particles are interacting with the nose.",
"The 18 miles thing is pointing out that even after the smell has traveled for 18 miles and has been very dispersed through the air, the animal's nose can still detect the very small concentration of particles.",
"It may be more accurate to say that an animal can ... | [
"So how are the particles traveling that fast? If a shark can smell blood a mile away, wouldn't it take a long time for the smell to get to the shark? Then by the time the shark reached the source of the smell, it'd be gone?"
] | [
"that fast?",
"How fast? Do you have any idea how fast it actually spreads?",
"Then by the time the shark reached the source of the smell, it'd be gone?",
"I am sure it happens most of the time."
] |
[
"How fast can a wheel spin?"
] | [
false
] | Is there a limit to how fast a wheel can spin? Say if you put a skateboard down a large flat ramp held on a track would the wheels continue to build up speed indefinitely until the ramp bottomed out? A Bugatti Vayron can do 400kph the wheels must be spinning at a very large RPM. But what if the car was held in place and suspended from the ground, could the wheels spin at an even faster speed? Is there a limit of rotation that gravity will “allow”? Sorry for being thick :( | [
"There is a practical limit (in addition to that imposed by relativity). I once got ahold of one of those toy gyroscopes and wanted to know how much angular momentum I could give it and try to make it precess. I used an air compressor to blow across it and spin it up. I got it so fast that the centrifugal force ex... | [
"My dad used to work in a Industrial workshop that often used ",
"ball bearings",
". ",
"One day at lunch they decided to have some fun and took one of the compressors at the shop (and not one of those small ones you have in the garage, I'm talking a giant industrial motherfu***) and some bearings and went ou... | [
"There is a limit, but it's not because of gravity. No object can move faster than the speed of light relative to any other object. So, relative to the axis of the wheel, no part of the rim can exceed the speed of light. Predicting what you would actually observe during the process of spinning the wheel up from 0 R... |
[
"Do green and purple stars exist?"
] | [
false
] | According to the Hertzsprung-Russell diagram, stars can be blue, red, orange, yellow, and even white. But why aren’t green and violet (purple) in the diagram? Have green or purple stars ever been observed in the universe? | [
"Stars are pretty close to \"black body\" emitters. They emit a wide range of wavelengths, depending on temperature. The hotter the stellar atmosphere is, the shorter/bluer the peak wavelength is (although the definition of exactly where the peak is depends on if you're looking at frequency or wavelength).",
"Whe... | [
"So the interesting thing about red shift is that if you red shift a black body spectrum, it stays a black body spectrum! Basically you can make a blue 10,000 K star look like a red 3,000K star, but you can't make a blue star look green.",
"This actually makes it harder to find the distance or velocity of stars -... | [
"Ah interesting, so green and purple are incorporated into the white but because there are so many other colors also being emitted, it won't just show as a singular color?",
"Thank you so much for your response. This is so interesting!"
] |
[
"Is there anywhere i can download science papers?"
] | [
false
] | [deleted] | [
"Google scholar is where I look for my papers. Most of the older seminal papers are free."
] | [
"Go to a library in a univ near you. If you cant find it via their computers, then most good univ libraries will have ILL services that will get the articles for you somehow. ",
"If you still can't find them and you don't want more than 1 paper every 2 weeks you can PM me, I can try."
] | [
"arxiv.org has preprints of physics and related fields. The papers are generally new, however. ",
"Being a preprint server, a lot of stuff on there is cutting edge, but there's also a lot of crap. I wouldn't blindly trust anything from outside of mainstream US and Western European universities."
] |
[
"Why does a brain’s surface area matter so much?"
] | [
false
] | Wouldn’t a smooth brain have a higher internal volume than a wrinkled brain and a slightly higher neutron capacity? | [
"If volume were all that mattered, then yes, the More you could stuff into a skull the better. But organised connections are crucial to the ability to effectively process information. ",
"Evolutionarily speaking, cortex (outer surface of the brain) is a relatively recent innovation, so as a latecomer to the brain... | [
"It's not only blood vessels and like. It's much more.",
"Cannot just say what's the function of the inside of the brain. There's a lot of structures \"inside\". There are parts that control emotions, memories, autonomic functions like blood pressure, and respiration. And this is a very very vrrh very small tiny ... | [
"Here",
" is a good overview of the various layers and types of cortex that our brain possesses. ",
"If you want to actually see many of the various known portions of the brain, ",
"Here",
" is an interactive tool that you can step through coronal slices and highlight structures (and even see an MRI with la... |
[
"If there WAS an air bubble in a needle that was injected into someone what damage would it cause and why?"
] | [
false
] | I know care is always taken to avoid having an air bubble in a needle by flicking it and squirting a little out, but with my basic understanding of the physics and medicine that might explain this I can't think of why this could cause any damage. What would it do? | [
"They can occlude blood vessels because (if the bubble is large enough) the surface tension of the bubble is too great for the blood to break through it, so it acts like a solid object and stops blood flow. The severity of the damage they can cause is dependent on their size and where in the vasculature they lodge ... | [
"Air bubbles are only really dangerous if injected directly into a blood vessel. For subcutaneous injections like insulin, the small amount of air that could possibly fill the syringe would just be absorbed by the body, from what I understand. I'm a nurse and I frequently give subcutaneous injections of a blood thi... | [
"I don't believe it happens very often at all. I've really only heard warnings about it, and I've never heard of it happening to any nurse I've met. An embolism could be made up of a blood clot, fat embolus, foreign object, or air embolus, among other things. I'm sure it probably happens with few side effects if it... |
[
"Just saw this on /r/wtf. Can anyone tell me what the heck this scary little thing is?"
] | [
false
] | What is this thing? Are those really teeth? Can teeth even be that small? Credit for this find goes to suggested coming here with it, so I did just that. | [
"I'm no expert, but I would say it is a fish related to the ",
"Danionella dracula",
". Notice the same holes next to the eyes. Same family as the zebra fish."
] | [
"Thanks! That does look very similar. :)"
] | [
"You might want to try using ",
"google reverse image search",
". It's not a well known service but it's very handy."
] |
[
"Is the surface of a black hole perfectly flat or can it have geographical features like mountains?"
] | [
false
] | Are they perfect spheres due to the immense gravity? Side question: If you could somehow take a chunk/rock off a black hole that's the size of a fist, and somehow keep it secure on Earth without ramifications - what state of matter would it be and could it be a classifiable element? | [
"If our understanding of gravity is correct, black holes don't have a surface at all. The event horizon that people talk about is not a physical barrier, it's a mathematical point of no return. In the current understanding of gravity (though alternate theories exist) the mass of the black hole is concentrated into ... | [
"So if an outside observer was to watch an object get sucked in by a black hole, it would appear to them to be happening very slowly?"
] | [
"The thing with gravitational time dilation is that it depends on who is viewing it (i.e. the point of reference). Time only seems to slow down near the even horizon for somebody watching from further away. Time actually passes completely normal for an object that is there and thus it doesn't really take years to p... |
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