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lzipe | What would happen if a person plucks their eye out of their eyesocket, leaving the optical nerve attached and they hold the eye in front of their other eye. What would they see? | askscience | http://www.reddit.com/r/askscience/comments/lzipe/what_would_happen_if_a_person_plucks_their_eye/ | {
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"You would see an overlapping image of your intact eye and a floating bloody eye. Similar to looking at your nose or just in front of it, the brain is capable of handling two visual inputs that don't align up perfectly. ",
"You would see an overlapping image of your intact eye and a floating bloody eye. Similar to looking at your nose or just in front of it, the brain is capable of handling two visual inputs that don't align up perfectly. "
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mhofd | Why does rubbing alcohol feel slightly warm to the touch when I pour it over my skin? | askscience | http://www.reddit.com/r/askscience/comments/mhofd/why_does_rubbing_alcohol_feel_slightly_warm_to/ | {
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"It does? Without testing this right now I would say it should feel slightly cold due to rapid evaporation. Compare it with water and report back.",
"It does? Without testing this right now I would say it should feel slightly cold due to rapid evaporation. Compare it with water and report back."
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8s66y9 | what is the difference between a 200 calorie fasting deficit and a 200 calorie burning workout? | When trying to lose weight, what would be the benefits/drawbacks of achieving the deficit using these 2 methods?
In other words,
If my daily maintenance calorie level is 2000, what is the difference between:
1. Only eating 1800 calories of food
2. Eating 2000 calories and burning 200 by working out. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8s66y9/eli5_what_is_the_difference_between_a_200_calorie/ | {
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"Working out gives you the cardiovascular benefits as well as raising your metabolism for a couple hours after workout which burns more calories. ",
"Exercise has the additional health benefits, but there are nutritional benefits to calorie burning through working out. \nThe difference between cutting intake down to 1000 kcal, and eating 2000kcal and exercising off 1000 is you get the nutritional benefit from the food, vitamins/minerals/protein/oils. \nThe distinction changes in the difference from junk food. The kind of food is more important in this than how much. Eating 1000 kcal of fast food is probably better for you than 2000kcal of fast food and 1000kcal burnt in exercise.",
"I'd say there are 3 main advantages of exercising instead of just limiting food intake :\n\n1) Calorie burning continues a bit after the duration of the exercise. \n\nIt is possible to evaluate the amount of burnt calories based on heart rate ([link](_URL_0_)).\nSo when doing exercise, as long as your heart rate is over your normal one, you burn more calories than you would not doing exercise.\n\n2) Exercising encourages your body to keep muscle mass.\n\nMuscles consume energy. When you are in calorie deficit, your body needs to find extra energy and tries to balance the metabolism. It can be done through ketosis (burning the fat stock) but it can also be done by breaking down muscles if the body thinks there are more than what it needs.\n\n3) Fasting or eating less can lead to unbalanced diet (especially toward nutrients intake)\n\nIt's important to have a balanced diet with all the nutrients the body needs and sometimes cannot produce. Nutrients do not necessarily account for calorie (e.g. vitamins and minerals) but are very important for the body to function properly."
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2o1mkq | When I make my instant coffee too weak, it tastes sweet, not bitter. Why? | Its Maxwell House original blend. I buy it because its the easiest way to get a caffeine kick without making a whole pot. When I say bitter I don't mean in a good way, I mean in a bareable way (its instant coffee... not 80% chocolate). I still don't understand how reducing the concentration could change the taste from bitter to sweet though.
Just to clarify, not a pleasant sweet, probably even worse than the not pleasant bitter taste. I should just buy an aeropress, I know. | askscience | http://www.reddit.com/r/askscience/comments/2o1mkq/when_i_make_my_instant_coffee_too_weak_it_tastes/ | {
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"Not everything that leaches out of coffee is bitter, depending on the grain size, roast type, temp of the water, and amount of time left in that water different plant chemicals will leach out. \n\nI have been told that using the \"cold brew\" method you can almost make \"sweet\" coffee. The way it was explained to me was that different chemicals come out of the bean at different times, and the trick is to stop before it gets too bitter.\n\nPerhaps when you only use a small amount of coffee there is enough water to leach the sweeter chemicals out, but not enough grains to contribute enough of the bitter ones.\n\nThis is my best guess, a real coffee nut would perhaps know more. Personally I can't even stand the smell of coffee...so my direct experience is limited.",
"Hello, I created a new account just to answer this question! \n\nThere are many factors in why a coffee tastes bitter or not, but the largest contributing factors are dose, grind, and water temperature. Since you are using instant coffee, and I'm assuming you are using approximately the same water temperature, the only factor here is dosage. Why is the taste of the coffee changing with the dose? \n\nFirst, let's define what coffee can taste like. The two ends of the spectrum are acidity and bitterness, with sweetness in the middle. Increasing dose _can_ increase the bitterness of an extraction. Too little of a dose, and the coffee will have a light mouth-feel with an acidic tint to it. I can explain the science of this with traditional extraction methods, so take this with a grain of salt when thinking of instant coffee. \n\n Extraction is the process of removing mass from coffee grounds with water. Mass extracted from the grounds are either soluble or insoluble. Solubles include solids, which provide taste and determines the coffee's concentration, and gases, which produce aroma. Insolubles are solids and oils held in suspension. These are mostly comprised of large protein molecules and fragments of fiber. The insoluble solids combine with oil to form what is called \"brew colloids\". This contributes heavily to the coffee's body, taste, and aroma. It also alters flavor by trapping and later releasing soluble solids and gases and by buffering acidity. Espresso is a little different with the way it handles insolubles. The insolubles in espresso or either held in suspension or an _emulsion_. Suspended solids make up the espresso's body, but not flavor. The emulsion is a dispersion of tiny oil droplets surrounded by liquid. These oils contribute to body, taste, aroma, and decrease the perceived bitterness of an espresso by coating the tongue. \n\n Ok, so what? What does that have to do with bitterness? \n\n Well, both solubles and insolubles contribute to a coffee's concentration. Since you are making instant, you are only dealing with solubles. The amount of solubles you extract is directly proportionate with the way the coffee will taste. Since you are \"extracting\" all the solubles of the instant coffee, you can directly control this with dosage alone. This will not change if you buy an Aeropress and start brewing real coffee. \n\nAlso instant coffee is made with the lesser of the two coffee species (_coffea canephora_) and generally does not have the taste complexities of _coffea arabica_. \n\n\nSource - 5 years Barista experience in Seattle and my trusty copy of _The Professional Baristas Handbook_ by Scott Rao. \n"
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wjo0v | What makes psychedelics supposedly so effective in treating alcoholism? | And to what level of verifiable detail can you explain the process? | askscience | http://www.reddit.com/r/askscience/comments/wjo0v/what_makes_psychedelics_supposedly_so_effective/ | {
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zfvp3 | Roughly how long will it be before a manned ship could catch up with, and retrieve, Voyager 1? | That little guy is 11 billion miles from Earth at the moment.
> Astronomers like to think of distances in terms of 'light-years.' Well, we're not anything like a 'light-year,' but we're now a substantial fraction of a 'light-day' from the Earth," says Gurnett. "And I just find that extremely impressive. [Source](_URL_0_)
So, with the current (or predicted) rate of technological advancement, when is it feasible we could catch up with it?
I'd like to think that we would so that it could be housed in a museum..but I guess we wouldn't head in that direction unless it were part of a *much* longer trip. | askscience | http://www.reddit.com/r/askscience/comments/zfvp3/roughly_how_long_will_it_be_before_a_manned_ship/ | {
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k649l | What is the name of the phenomena where you are more likely to notice something because you encountered it before? | For instance, you may come across a really random word and then the next day you hear someone use it. Or perhaps you noted a number and now you are seeing it everywhere.
It seems to defy coincidence. | askscience | http://www.reddit.com/r/askscience/comments/k649l/what_is_the_name_of_the_phenomena_where_you_are/ | {
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"[Baader-Meinhof Phenomenon](_URL_0_)? Although I'd go with pyxlated's reply above.",
"[Baader-Meinhof Phenomenon](_URL_0_)? Although I'd go with pyxlated's reply above."
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d5wegr | where will energy go when the universe goes through proton decay? | From my understanding proton decay will be one of the last stages of the universe that we understand, thereafter atoms will no longer exist. If energy cant be destroyed does it stay in the protons flying around or are they actually gone? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d5wegr/eli5_where_will_energy_go_when_the_universe_goes/ | {
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"It will be converted into forms of energy such as heat and light - and bear in mind that proton decay is only one possible theory. There are many others.",
"Protons decay into lighter subatomic particles. So a large proportion of the energy/mass of the proton would be conserved in the other particles. There will probably be some photons also emitted(light). I expect at some point most stuff would decause leaving just pure photons and maybe other force carriers. Have a look up at the heat death of the universe. Where all the photons would be red shifted to absolute zero. \n\nAlso on cosmological scales energy is NOT conserved. In particular dark energy is believed to be increasing, also the whole expansion of the universe as a result doesn't conserve energy.",
"The energy would still be there, just more diffuse. It would be in the form of smaller packets of energy like muons and various neutrinos. Despite significant experimental effort, proton decay has never been observed.",
"mind my words once we get into interstellar travel a lot of our assumptions of the universe will just be the same horseshit as people thinking the earth is flat a 1000 years ago.",
"Even our brightest minds don't know, and you should be weary of any comment that purports itself as iron-clad.",
"Protons would decay into quarks, heat and photons and those would become more and more spread out. My understanding is that the universe, while a closed system, is also infinite. So I imagine that similar to how .99999 repeating is equal to 1, the low energy spread over an infinite area would be empty.",
"The short answer: it's going somewhere we can't measure.\n\nWe can only measure things that we can measure. The proton decay means all the energy is going and going and suddenly becomes something.\n\nImaging a small room with a cup with some ice inside. The ice will melt, sure, and some of the energy will condensate around the cup and you will find it wet. If you measure all the energy from the inside of the cup plus the condensation and the temperature/humidity of the room you will find it's the same overall energy with probably some 'lost'. Where is that 'lost' energy? Now, how about outside of the room? It's definitely not the scope of your measurement but even the tiniest bit of change can influence to outside.\n\nScience is like that: We can only measure what we can measure. Proton decay it's going somewhere but we don't know what will become of it.",
"Conservation of energy might be violated on cosmological scales. But we don't no enough about it.",
"Ever since the Big Bang, our universe, like all closed systems, has been on an inexorable march toward thermodynamic equilibrium. All the energy peaks currently bound up in stars will eventually be expended, leaving nothing but a cold, dark, ever-expanding cloud of rocks, gas, and dust.\n\nAs for proton decay, that's an unproven theory. But should it be true, the same principal applies. Any potential energy bound up in the proton would simply be released into the universe.",
"The energy isn't \"gone\" but what happens is that all matter is a form of \"concentrated energy\" and things only \"happen\" when there is an energy differential. So the \"heat death\" of the universe is just that the entire universe is simply at the same energy level - no matter exists, nothing \"happens\" anymore. \n\nNothing happens means literally that - light is energy, and any form of contact or cause and effect interaction requires energy transfer which implies energy differential. (this is ELI5 so this isn't entirely accurate at the quantum level but good enough, I hope)",
"Are you asking the Last Question?",
"I actually know this one. So the only element that doesn’t gain electrons is iron. Iron is also the ending product of stars as fusion stops working when iron is all that is left. So the end result of every atom in the universe in going to end up as iron trillions and trillions of years from now. Unless by energy you meant photon, which is different.",
"While this may not answer your question, here is an astonishingly interesting [video of the universe's entire life cycle](_URL_0_). I thought it was really cool to see, and it's also well made!",
"The energy will remain in the form of photons, electromagnetic radiation, traveling forever through the empty universe. The average energy contained in a given volume of the universe will continually decline but never actually reach zero.\n\nUnless the concept of the heat death of the universe is wrong. Everything could end up falling back into a singularity that could explode in a new big bang and all new universe.",
"For anyone who wants to see this in a YT video, this is called Time lapse of the future: a journey to the end of time.\n\n_URL_0_",
"Energy is only conserved in an unchanging system, but the universe isn't unchanging, it's expanding. As it expands, light (and other electromagnetic radiation) gets stretched, and will have a longer wavelength. A longer wavelength means lower energy, and that energy is just lost, not converted and not conserved. [Here’s a video ](_URL_0_)going into this more in depth.",
"By the time the universe goes through proton decay, its safe to assume that perception/awareness no longer exists. And without sonething to witness the universe, it wouldn't be that much of a stretch to say that it no longer exists. In short, matter only \"matters\" because there's someone around for it to \"matter\" to.",
"It will convert to heat, the heat will be distributed equally in the universe, until everything will be the same temperature. Then nothing will happen, and nothing will keep happening, forever. That is, if the theory about dark matter integrity is correct.",
"What we are learning about dark matter and dark energy could be groundbreaking and it defies some logic. It appears that dark matter is somehow being created out of nothing. Obviously we don't know if that's totally true because we just started really studying it but the darks stuff is crazy and recommend reading up on it.",
"As of today, according to the laws of thermodynamics, energy exchanges between places of high energy to places of low energy, and the rate of this energy transfer is tied to the difference of the two energy levels. Example: heat transfers much faster from water at 200°F to ice at 32°F than it does from water at 60°F to the same ice. So the smaller the difference in energy between two interacting systems, the slower heat exchanges between them. So the end of the universe as we know it will occur once every particle in the universe reaches equilibrium and all the energy of the universe is spread uniformly across everything with no heat or energy transfer between them. Logic tells us this will eventually happen, but the thing is that the energy transfer of two basically similar energy levels is so minute that it approaches 0 but never reaches it, meaning that equilibrium will take an infinite amount of time to reach. Meaning it will truly never happen. \n\n\nBut by then who knows, a universe in complete equilibrium may have different rules, and maybe all the energy of the universe will suck itself together and make another big bang. Nobody knows.",
"I’m not sure about proton decay, but here’s an explanation of your question, “where does the energy go?”\n\nThe answer is always that the energy goes wherever it is easiest for it to get to. If I have a glass of ice water, it is very easy for heat to go into it. The glass will soon warm up and the ice will melt. Heat will have moved from the air or the table or your hand into the glass, and the colder the glass is, the faster the heat goes into it.\n\nBut what if there is nothing that is cold or hot anymore? The energy is still there, but it doesn’t move because it doesn’t have a colder thing to move to. This is true for all energy. A ball will roll down a hill, but will stay still on a flat surface. A battery will send electricity around through a circuit from one side of itself to the other, but the electricity stops moving when there is no difference between the + side and the - side.\n\nSo where does the energy go at the end of the universe? It spreads out and fills in all the cold places and low places until everything has the same amount of energy and there is no hot and no cold. And then it goes nowhere.",
"Energy is not a substance. It's a way of quantifying certain physical states. For example when gunpowder explodes you can measure the kinetic, thermal, acoustic, etc energies of the expanding gases. This used to be chemical energy in the gunpowder mixture. The two states of gunpowder are different, but we can draw an equivalency between them with the concept of energy. Energy itself doesn't exist as a physical substance, it's an accounting mechanism like money. A TV that is worth $300 is not actually $300, it's just a way we assign it value. I can give you a couple pieces of paper from my wallet that we agree are also worth $300, but again the paper bills are not themselves $300. We just agree they are worth that much. $300 does not physically exist in this universe, just as 300 joules does not exist. They are both accounting concepts that we have created to measure something.\n\nTo answer your question, since energy is not a physical substance, it doesn't 'go' anywhere. It never has. If proton decay is possible then the physical state of the universe will change, but the quantity of energy will be conserved.",
"I read the first 15 replies and none of them are correct.\n\nProton decay has never been observed, and according to the standard model, isolated protons should never decay (due to color charge conservation, so no, they won't turn into photons).\n\nSomeone near the top mentioned that scientists have been able to put a *lower* bound on the half-life of the proton at 10^(32) years, and that's true, but that doesn't establish that proton decay is actually a thing, just that *if* it is a thing, it would take longer than that on average for any individual proton. The half-life could still be infinite, i.e. protons never decay, as predicted by the standard model.\n\nYou are certainly allowed to assume that the proton has a finite half-life and then see what theoretical consequences such an assumption has on current theories, but your question inherently assumes proton decay is predicted by the standard model, and it isn't.\n\nThe only saving grace is that on large enough time scales, it makes sense to assume that current theories (probably) break down, so just because current theories say the proton doesn't break down doesn't mean *actual* protons won't decay, but then the onus is on you to first find a new dynamics equation that can accurately produce predictions that align with all current measurements, and then we can discuss what this hypothetical new dynamics equation predicts.\n\nEdit: I read every top-level reply and some had kernels of truth but none ever the whole story.",
"It's honestly a non-event that doesn't matter. This is because we only have 3.7 Billion years before we hit the time barrier. After that, we literally run out of time, which is actually a finite resource. (Time being caused by sequential entanglement of particals along the T axis aka small particles strung together like a necklace in the 'time direction' makes time). Effectively, you could think of the existence as a water planet, and our unuverse's time is us, as a bubble, rising to the surface. The universe expands as it travels, but once we reach the surface, there's no more 'up' we can go, and the movement of time just ends.\n\nWell... maybe we can survive if we figure out how to mass produce temporal quantum entanglement ahead of us(extend our necklace of time particals or make our bubble float up into the air above the water's surface), but we'd need to survive to become a Kardeshev type lV status (a universe-spanning super-civilization ) to pull of something like that, at which point we've begun to rewrite the laws of physics and all bets are off.",
"We can't be sure, but in one theoretical model, the proton decays into a positron and two photons. So the mass of the proton largely becomes photons. Maybe.",
"I was under the impression that all energy would consume itself lastly being black holes? Essentially meaning that not even light will be able to penetrate the darkness, not that any light will remain...."
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bvlxal | how did rudy giuliani and michael bloomberg manage to clean up new york city? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/bvlxal/eli5_how_did_rudy_giuliani_and_michael_bloomberg/ | {
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"I dont know the full extent to which they tried to clean up nyc but they did go after some members of the mafia. Michael Franzese was one prominent member they went after.",
"There are competing theories, and only some of them involve Giuliani or Bloomberg. Here are a few of them:\n\nEconomics: the economy was improving at the time, so more jobs means fewer people poor and desperate enough to commit crime.\n\nInnovative police work: policing things like broken windows and graffiti lead to more neighborhoods that looked nice. Criminals are more likely to break windows if they *see evidence of other crimes being committed* in that area. Reduction of \"shabbiness\" of neighborhoods lead to a reduction in crime.\n\nLead in the water: some people are convinced that a tiny bit of lead in the water makes people aggressive. As we pushed to get lead out of the water, crime dropped.\n\nLegalized abortions: tons of crime is committed by poor men aged 15-25. Legal abortions after Roe v Wade passed in 1973 means that there was a large reduction in poor, potentially criminal men starting in around 1989, and indeed, the country saw crime drop off at that point, and cities that legalized abortion a few years earlier saw their crime drop a few years earlier.",
"There are two episodes of the podcast Reply All that talk about it. \n\nThe Crime Machine Parts 1 and 2. \n\nBasically the police started tracking crime stats in a very clever way and it allowed then to see patterns of crime and that allowed them to get very good at forcasting where to put resources.",
"Look at increases in real estate prices and rents during their tenures. Poor people left. Rich people commit crimes, of course, but usually not the kind of crimes you’re referring to in terms of “cleaning up the city.”"
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2vv4mf | What does the radial density profile of the gaseous planets look like? | When I've seen photos from probes of the gas giants, like Jupiter, they always look to have extremely well-defined boundaries.
I'm assuming this is because the width of the region where the density goes from scattering a lot of light to scattering very little is small in comparison the the width of the planet.
But this got me thinking - What does the density profile of gaseous planets look like? How much do we know and how did we learn it?
As an aside I've also wondered about rotation in the gas giants - I've assumed that they rotate, but does the rotation speed change as a function of radius? If there is differential rotation does it do anything interesting like drive macroscopic flows?
Thanks! | askscience | http://www.reddit.com/r/askscience/comments/2vv4mf/what_does_the_radial_density_profile_of_the/ | {
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"I don't have the relevant specific credentials to answer this, but the question was interesting enough to me that I went looking around.\n\n[This lecture slide set](_URL_3_) (Warning: 50mb PDF) about planetary and large moon interior composition was the best information I found. Take a look at pages 70-74 for your answer.\n\nThe highlights:\n\n[Radial structure diagram for Jupiter and Saturn](_URL_2_)\n\n[Radial density graph for Jupiter and Saturn](_URL_1_)\n\nSource: Lecture slides of Dr. Golabek, Planetary Physics and Chemistry, ETH Zurich: _URL_0_\n\nMy background: Engineering bachelors and masters degrees. Math and electrical eng specialty. Developer and energy analyst by trade.",
"The well-defined boundaries on the gas giants are as well-defined as Earth's, essentially. The top of any atmosphere is generally quite diffuse and ill-defined. For Earth space starts at [100 km above sea level](_URL_3_), but there's raging debate over that depending on who you ask. Jupiter, however, with its stronger gravitational pull, is able to hold on to more of an atmosphere more tightly. Just think of all the light weight hydrogen its been able to keep in its atmosphere. Unfortunately, I have nothing to back up this part, but it may be that Jupiter has a more well defined line between atmosphere and space than other planets.\n\nAs for differential rotation, Jupiter rotates faster at its equator than at its poles, but the interior is a trickier story. [This high school's online astronomy page](_URL_1_) offers a few insights:\n\n > There is no clear relationship between the interior and atmospheric rotation rates of the jovian planets. In Jupiter and Saturn, the interior rotation rate matches the polar rotation. In Uranus, the interior rotates more slowly than any part of the atmosphere. In Neptune, the reverse is true.\n\n[Source](_URL_0_). The info may or may not be out dated; I was unable to find excerpts from more recent editions.\n\n & nbsp;\n\nAdditionally, I was elated to see that the figures in the slides goorpy linked to are also in a [text book](_URL_2_) I have. The \"rocks\" mentioned in the figure are clarified (I use the word loosely) in the text:\n\n > The core is probably composed of relatively large quantities of iron and rock.\n\nBoy, wasn't that helpful. :/"
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"http://www.amazon.com/Astronomy-Beginners-Guide-Universe-Edition/dp/0130873071",
"http://www.castlerock.wednet.edu/HS/stello/Astronomy/TEXT/CHAISSON/BG307/HTML/BG30703.htm",
"http://www.amazon.com/Fundamental-Planetary-Science-Chemistry-Habitability/dp/052161855X/ref=sr_1_1?s=books&ie=UTF8&qid=1424147418&sr=1-1&keywords=fundamental+planetary+science",
"http://en.wikipedia.org/wiki/K%C3%A1rm%C3%A1n_line"
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1teoa7 | is there a universal weight unit scientists use? | I was just thinking how something on Earth that weighs 100 lb.s weighs 16.6 on the Moon. Is there a universal weight or density unit that scientists use or do they not have one because weight is relative? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1teoa7/is_there_a_universal_weight_unit_scientists_use/ | {
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"In science, you use mass instead of weight,",
"*Weight* is just another fancy word for *gravitational force*, the downwards pull the Earth does on some object. The proper unit in the SI system of units (which is the \"standard\" among scientists) is therefore the unit for force, a [newton](_URL_0_). A newton is roughly the weight of 0.1 kg on Earth.\n\nIt's technically incorrect to use a unit of mass to measure force. The mass of an object is the same everywhere, so when I for instance say that \"I would weight only 10 kg on the Moon\", what I mean is that \"I would weight as much as 10 kg of mass would weight on Earth\", while I would actually weight around 100 newtons (compared to around 600 newtons on Earth).\n\n**Edit**: Apparently there's such a thing as a pound-force.",
"Yes. \n\nUnits of mass are irrespective of the local gravitational acceleration. \n\nMass measures how much matter exists in an object. \n\nIn the SI system mass is measured with the Kilogram (kg) and in the American Engineering system mass is measured with the Pound Mass (LBM).\n\nIn all cases, the following relationship holds true. \n\nF = M * A or Force = Mass * Acceleration\n\n**Force** (what you think of as weight) is **equal** to the **mass of the object** ( LBM | KG ) **multiplied by** the **acceleration applied to the object** ( in this case the acceleration due to gravitational pull, which is greater for larger objects ). \n\nThe confusion stems from the American Engineering system which is set up so that on planet Earth at sea level the acceleration applied by the gravitational pull of the planet exerts 1 Pound of Force on a 1 Pound Mass object. \n\n"
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8xxx2d | why does alt-tabbing out of some fullscreen apps cause black screens or partial alt-tabbing? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8xxx2d/eli5_why_does_alttabbing_out_of_some_fullscreen/ | {
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"It depends on which fullscreen mode you're using.\n\nIf you use borderless fullscreen. It's basically windowed mode without the border to fill up 100 & #37; of the screen space. In this case, everything on the desktop is kept in memory and you can switch back to it in an instant.\n\nIf you use the real fullscreen mode, which is the case you're asking about. It releases desktop content from memory and let the app take exclusive control of the graphics card. When you alt-tab out of this fullscreen. It will take a second to re-render the desktop before it can be presented to you. That's why there's black screen."
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4bvd07 | how does upping the voltage of a cpu help overclock it? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4bvd07/eli5_how_does_upping_the_voltage_of_a_cpu_help/ | {
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"Imagine a CPU is like an engine in a car and you increased the speed of the engine without giving it more gas. Some of the cylinders would misfire because they didn't have enough fuel and the engine would start to run worse and worse until it died. This is an analogy of what the CPU does with the power it takes to run it. \n\nThe reason you need a steady supply of power is that the CPU has millions of tiny switches and gates inside of it that do the actual computing. They all use power and if the CPU doesn't have enough power to do the work then it will begin failing in ways that corrupt the data moving through the CPU which leads to a system crash. \n\nThe amount of power the CPU requires in order to run in a stable configuration is related to the clock speed of the CPU. The lower the clock speed, the less power it needs and the cooler the chip runs because some of that power is wasted as heat. \n\nAs you over clock the CPU, the logic gates are operating faster and so they require more power and if they don't get it then you get unstable operation or a crash.\n\nSo you increase the CPU speed until it starts to get unstable. Then you increase the voltage until it's stable. Then you repeat this process until it either starts running too hot, or adding additional power doesn't result in more stability. \n\nThe reason you don't just operate it at high power to begin with is because the TDP, or the amount of heat it needs to dissipate would be high and could shorten the life of the CPU and it would draw more power, run hotter, require larger cooling systems and more noise. \n\nIn general the CPU fabs err on the side of caution and you can safely over clock without increasing the voltage at all, but not as much as if you increased the voltage as well. \n\nIn more detail, you also have quantum effects with the electrons moving through the tiny little logic gates. The chip transistors are so small now that you have a lot of them in a very tiny area, and the space between them is so small that electrons can sometimes jump from one lane to another. As you increase the voltage you help stabilize the logic. \n\nWhen CPU's were made with much larger transistors and components there was tons of room for electrons to go bouncing around through the semi conducting circuitry of the chip. Like ball bearings inside of a barrel. But electrons have a fixed size, and as you make the circuits smaller and smaller it starts to look more like sucking BB's through a straw, which makes it harder for the electrons to move through the circuit and they require more of a push or pull to make it through. This potential is the voltage. We are getting close to the point where making the circuits smaller will become harder and harder until it's more like sucking a golf ball through a garden hose. "
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2snp7i | why is oceania the continent of new zealand, but isn't considered one of the 7 continents? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2snp7i/eli5why_is_oceania_the_continent_of_new_zealand/ | {
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"When used in the context of being a continent it includes Australia. Otherwise it just refers to a region of islands and not a continent.",
"It is, well more correctly Australia is. Many schools teach that there are 7 continents.\n\n* North America\n* South America\n* Africa\n* Europe\n* Asia\n* Australia\n* Antarctica\n\nThese the seven major geographic/political continents.\n\nIt's only in recent years that the continent of Australia has been referred to as Oceania, this is because they don't want to confuse the country and the continent and because it's not just the one country, but also includes places like New Zealand.\n\nThe problem with the definition of \"continent\" though is that it just means a large land mass. Hence why Europe and Asia are often called Eurasia, because it's one giant land mass that also connects to Africa, making it the supercontinent Afro-Eurasia.",
"[Obligatory CGPGrey continent video.](_URL_0_)\n\ntl;dw: The definition of \"continent\" is fuzzy to begin with.",
"Because what constitutes a continent has many definitions and there are also many views about what land masses Oceania comprises of.\n\nAlso, if you think about geography and plate tectonics, there are valid grounds for the definition of these continents, e.g. Europe forms one continental tectonic plate, Africa another, Australia another. The Oceanic Islands happen to occur on a oceanic plate and such islands are always difficult for the continental definition, because, well, they are not that, continental.\n\nBut to be honest, the main reason is probably because the region has so little landmass so they are deemed insignificant and are simply disregarded.",
"New Zealand is actually separated on to two continents, the Australasian (or IndoAustralian) plate, and the Pacific plate.\n\nOceania is a collective term for Australia, NZ, and many of the pacific islands. "
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rmp4h | Do your taste buds dull with age? | I've noticed that food which repulsed me as a kid (spicy food, vinegar,etc) are now things I seek out and enjoy. Is this because my taste buds change, or because they are less sensitive and require food with a stronger taste?
I didn't see this anywhere, so I apologize if it's already been asked/answered. | askscience | http://www.reddit.com/r/askscience/comments/rmp4h/do_your_taste_buds_dull_with_age/ | {
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"Dental Student here.\n\nYes taste changes. Taste buds atrophy, the nerve connections to your brain increase or decrease depending on diet, your diet can alter how you taste. there are SO many reasons why taste changes as you age. \n\nAs Hanzelitus said below, smoking playes a HUGE role in how one tastes - basically decreasing it significantly because of tar buildup in the structure of your taste bud.\n\nTast buds are basically a micro food trap. Mastication and salivary digestion break down your food into little pieces and some of those small particles go into your taste bud apparatus which, depending on the chemicals present, elicit a specific release of neurotransmitters in the taste bud which active different neural pathways to the brain. \n\nIn addition to signal transduction by taste receptor cells, it is also clear that the sense of smell profoundly affects the sensation of taste. Think about how tastes are blunted and sometimes different when your sense of smell is disrupted due to a cold.\n\nCurrently, and I say currently because Umami was recently added, we have 5 tastes: \n\n* Sweet - usually indicates energy rich nutrients\n* Umami - the taste of amino acids (e.g. meat broth or aged cheese)\n* Salty - allows modulating diet for electrolyte balance\n* Sour - typically the taste of acids\n* Bitter - allows sensing of diverse natural toxins\n\nNone of these tastes are elicited by a single chemical. Also, there are thresholds for detection of taste that differ among chemicals that taste the same. For example, sucrose, 1-propyl-2 amino-4-nitrobenzene and lactose all taste sweet to humans, but the sweet taste is elicited by these chemicals at concentrations of roughly 10 mM, 2 uM and 30 mM respectively - a range of potency of roughly 15,000-fold. Substances sensed as bitter typically have very low thresholds.\n\nExamples of some human thresholds:\n\n* Salty -- > NaCl -- > 0.01 M\n* Sour -- > HCl -- > 0.0009M\n* Sweet -- > Sucrose -- > 0.01 M\n* Bitter -- > Quinine -- > 0.000008 M\n* Umami -- > Glutamate -- > 0.0007 M\n\nSo from this, as we age, our taste buds thresholds are higher, requiring more of a specific chemical to elicit a response.\n",
"My mother has worked in nursing homes for the past 30 years, and has seen her fair share of people from the 55+ range over that time period. I apologize because this is more the sum total of 30 years of observation, and not scientific, per se, but I think it will answer your question. And the answer is - yes.\n\nAccording to my mother, about 50% of the people who live in her nursing home lose a significant amount of weight, because they stop eating. For certain people, this is good. For others, this is monumentally bad, and it leads to death. My mom started wondering why people were literally wasting away before her eyes. She came to realize that it was because people were not eating. She was a high enough level person that she could effectuate change in this regard, so she undertook some independent analysis. For a number of months (I forget the number) she started eating 2 out of 3 meals at the facility, selecting from only the options that the residents had. She didn't tell anyone she was doing this. She thought that maybe the issue was as simple as bad food. She found, however, that the food at the facility was notably better than the food she generally prepared at home (she never told me this until I was well out of the house). Mom was no 5-star chef, but the food she made was always pretty good, to my mind. She continued this experiment fo quite some time to see if maybe the quality of the food was just a fluke. But quality remained consistent throughout. She then started working food questions into her interactions with all the residents. The consensus seemed to be that the food was adequate, but no one was particularly excited about eating or the food. So she tried all kinds of things to generate interest in the food, adding significant spices, making meal time at the home more fun, etc etc. None of these things worked, people still didn't eat, and there were still weight loss problems. In the end, the comments of one particularly erudite old woman (who had been a resident for a longer-than average amount of time) explained it best \"the food doesn't taste as good as it used to.\" From this, it occurred to my mother that it wasn't the food that was the problem, it was the consumers. Based on some unknown process, their ability to taste the food appeared to be dwindling.\n\nEDIT - TL;DR - Yes, sense of taste appears to dull over time."
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1m3yeo | About to start a major research project, any tips for organizing research and sources for later use? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1m3yeo/about_to_start_a_major_research_project_any_tips/ | {
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"Maybe that's obvious, but still: Use a reference manager. Zotero is free and popular, Citavi is my personal favourite.",
"With every book, create your own index as you read to use for citations and relevant information later on. Also a good idea to write up brief summaries of each chapter and book for quick reference."
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alp039 | Is there any difference between a block of ice and the same block of ice that received a certain amount of energy but not enough to melt it? | Well obviously except for the fact that the the one that receive energy will melt faster. | askscience | https://www.reddit.com/r/askscience/comments/alp039/is_there_any_difference_between_a_block_of_ice/ | {
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"They will be at different temperatures. If both start at their melting point, then the one that received energy would be partially melted.",
"Really interesting question. You're wondering what happens during that latent heat of phase change.\n\nAs I understand it, the temperature doesn't change because the kinetic energies of the molecules isn't changing. They're not bumping into a thermometer any more or less and the measured temperature doesn't change.\n\nThe bond between molecules that needs to be broken (when heating up). The energy goes into breaking those bonds.\n\nI can't find a really specific description of what's changing. This is the best one I found:\n\n_URL_0_\n\n\"Latent heat arises from the work required to overcome the forces that hold together atoms or molecules in a material. The regular structure of a crystalline solid is maintained by forces of attraction among its individual atoms, which oscillate slightly about their average positions in the crystal lattice. As the temperature increases, these motions become increasingly violent until, at the melting point, the attractive forces are no longer sufficient to maintain the stability of the crystal lattice. However, additional heat (the latent heat of fusion) must be added (at constant temperature) in order to accomplish the transition to the even more-disordered liquid state, in which the individual particles are no longer held in fixed lattice positions but are free to move about through the liquid. \""
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379q44 | how did california get so unlucky when it comes to water shortage? why isn't it affecting oregon and washington? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/379q44/eli5how_did_california_get_so_unlucky_when_it/ | {
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"It is affecting Oregon and Washington. There is almost no snow pack on any of the mountains which means drought. The problem is the population of California is so much more than Oregon and Washington. Also, the western parts of OR snd WA are temperate rainforests. They generally get more rain than California anyway."
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ntrt0 | the little pi thing on the bottom of every page on reddit | My cursor passed over it by chance today, now I'm curious what "Rendered by PID 23270 on app-24 running fd50047" means.
edit: bottom right in case you couldn't figure that out (but I'm sure you did). | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ntrt0/eli5_the_little_pi_thing_on_the_bottom_of_every/ | {
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"This has been asked before but it is hard to search for. \n\nReddit as a whole has a lot of people visiting the website at any given time. That many people would be too much for just one computer, so there's a special computer that moves each visitor to another computer (in a bank of computers) so each individual computer gets less work. \n\nThere are also different versions of reddit, when the developers add features or fix bugs. These are all supposed to go on all the computers taking requests but one might be missed (maybe the admins were drinking beer while they were updating).\n\nThe little mouseover tells you want computer is running the webpage you're looking at, and what version of reddit is running, and some other information, so if something goes wrong, there's an easy way to see what computer is messing up.",
"[It sounded familiar :](_URL_0_) search for Pi\n",
"The real explanation would probably be the processor and computer the particular webpage is running off of so developers/ reddit can tell what went wrong and where. But that is just a guess.",
"If you click on it, it will take you to Mozart's Ghost, which is a program that allows the Praetorians to access secure government files.",
"It is an 'homage' to that movie.. you know\n\nThe Computer. With that girl from The Bus.",
"PID is *Process ID*, the numerical identifier of the linux process that is running the server.\n\napp-24 is an identifier, probably the hostname, of the server that handled your request.\n\nfd50047 is the beginning of a SHA hash that identifies the current commit, or \"version\" of reddit that was served.\n\nTL;DR: which server and what version of reddit.",
"TIL\n\nnever noticed that before, weird",
"When I was in primary school, the Grolier online encyclopedia had this hyperlinked period in the bottom of the page that could bypass the login. It was pretty boss.\n",
"Never saw it before... and now I'll always see it. ",
"This thing < 3 ?? I'm confused ",
"TIL i am oblivious to the small details of my everyday routine ",
"I never make all the way to the bottom of the page.",
"How long has that been there? I never noticed that before.",
"This has been asked before but it is hard to search for. \n\nReddit as a whole has a lot of people visiting the website at any given time. That many people would be too much for just one computer, so there's a special computer that moves each visitor to another computer (in a bank of computers) so each individual computer gets less work. \n\nThere are also different versions of reddit, when the developers add features or fix bugs. These are all supposed to go on all the computers taking requests but one might be missed (maybe the admins were drinking beer while they were updating).\n\nThe little mouseover tells you want computer is running the webpage you're looking at, and what version of reddit is running, and some other information, so if something goes wrong, there's an easy way to see what computer is messing up.",
"[It sounded familiar :](_URL_0_) search for Pi\n",
"The real explanation would probably be the processor and computer the particular webpage is running off of so developers/ reddit can tell what went wrong and where. But that is just a guess.",
"If you click on it, it will take you to Mozart's Ghost, which is a program that allows the Praetorians to access secure government files.",
"It is an 'homage' to that movie.. you know\n\nThe Computer. With that girl from The Bus.",
"PID is *Process ID*, the numerical identifier of the linux process that is running the server.\n\napp-24 is an identifier, probably the hostname, of the server that handled your request.\n\nfd50047 is the beginning of a SHA hash that identifies the current commit, or \"version\" of reddit that was served.\n\nTL;DR: which server and what version of reddit.",
"TIL\n\nnever noticed that before, weird",
"When I was in primary school, the Grolier online encyclopedia had this hyperlinked period in the bottom of the page that could bypass the login. It was pretty boss.\n",
"Never saw it before... and now I'll always see it. ",
"This thing < 3 ?? I'm confused ",
"TIL i am oblivious to the small details of my everyday routine ",
"I never make all the way to the bottom of the page.",
"How long has that been there? I never noticed that before."
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59lesr | Were there any areas of science or industry where the Soviet Union was ahead of the United States? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/59lesr/were_there_any_areas_of_science_or_industry_where/ | {
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"It's maybe more \"parallel\" than \"ahead\", but one major area the Soviet Union pursued that the West mostly ignored was bacteriophage therapy. Phage therapy is the injection of viruses into the body that target and kill bacteria. \n\nIn the Soviet Union, availability of modern broad-specturm antibiotics like penicillin was limited which necessitated an alternative. Phages can be more effective with fewer downsides as they only kill the disease-causing bacteria, not beneficial \"good\" bacteria. The downside is they are difficult to target because they only kill one specific strain of bacteria. It's possible a given disease could be caused by 10 slightly different strains of bacteria. For phage therapy your doctor would have to run tests and determine the precise strain and administer the correct phage. In the West they would just give you an antibiotic that kills all 10 and send you on your way. \n\nWith the recent discoveries of antibiotic resistant bacteria and increased access to former Soviet states there is a renewed interest in bacteriophages. \n\nI'm not a doctor or historian, but most of what I know is from *The Forgotten Cure* by Anna Kuchment, or articles like [Phage therapy gets revitalized](_URL_0_) and [Bacteriophage Therapy](_URL_1_)",
"Soviet industrial plans through the year 2000 have emphasized greater variety and higher quality in metals production to keep heavy industry competitive with the West. But the machinery and production systems available to Soviet metallurgists in 1989 showed no signs of improving the inconsistent record the industry had established in meeting such goals. Following the Stalinist pattern, great success in some areas was hampered by breakdown in others. In the late 1980s, escape from this dilemma seemed no more likely than in earlier years.\n\nSince the 1970s, the Soviet Union has led the world in the production of iron, steel, and rolled metals. In 1987 it produced about 162 million tons of steel, 114 million tons of rolled metal, and 20 million tons of steel pipe. Each of these figures was an increase of more than 2.5 times over those of 1960. Metallurgy has been the largest and fastest growing branch of Soviet industry, and metals supply remained vital to growth in virtually all other branches of industry. But yearly production increases were becoming more difficult because the cost of raw materials rose consistently in the 1980s, especially for metals such as molybdenum, nickel, magnesium, and rare earth metals, which were in increasing demand for high-quality steel alloys.\n\nIn the mid-1980s, the metallurgy industry was not meeting its goals for supplying high-quality finished metal to the manufacturing industries. Those industries were demanding higher-quality and stronger metals for new applications, such as high-pressure pipelines for oil and gas, high-capacity dump trucks and excavators, industrial buildings with large roof spans, corrosion-resistant pipe for the chemical industry, coated and treated rolled metals, and steel with high conductivity for electrical transformers. As military equipment became more sophisticated, it too required improved quality and performance from metal products. On the development side, advances in lightmetal alloys using aluminum, magnesium, and titanium did provide materials for military aircraft and missiles that were among the best in the world.",
"One could argue that their were ahead on certain areas of space exploration. The U.S. had the capability to launch a satellite about a year before the Soviets but interagency conflicts prevented it. That said the Russians still pulled significant achievements especially around space probes. Their rocket engines have been recognised as one the best until few years ago. \n\nTheir research may have been ahead in several areas but the lack of information around it and the anonymity of the researchers makes very difficult to actually assess it. For instance I know Russians explore the use of viruses to combat cancer decades ago."
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b69n09 | How were Newton's 3 laws of motion first proven to be true? | While I was taught to accept these principles as true (and have little doubt in their validity), I am curious as to how we were first able to scientifically prove them to be true. I ask this because in Newton's first laws of motion, couldn't one be skeptical as to the statement if we did not have a full understanding of gravity? | askscience | https://www.reddit.com/r/askscience/comments/b69n09/how_were_newtons_3_laws_of_motion_first_proven_to/ | {
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"If you don't get an answer here, you can try /r/askhistorians, /r/historyofscience, /r/historyofideas, or /r/philosophyofscience.",
"A lot of the ideas aren't new ones, but he was famous for bringing them all together and publishing them. You have principles of Newton's 3 laws around as early as 1000-1100 AD. The laws were derived from experiments trying to figure out the order of the universe, not the other way around. It is the scientific method at work. He more or less developed the field of classical mechanics as we know it today. Check out some pages if you want to read up on it:\n\n & #x200B;\n\n[_URL_0_](_URL_2_)\n\n[_URL_3_](_URL_1_)\n\n & #x200B;\n\n > couldn't one be skeptical as to the statement if we did not have a full understanding of gravity?\n\nWe *still* don't have a good understanding of gravity. /s ^((Kinda))\n\n & #x200B;\n\nWe developed the formulas of gravity and mechanics empirically from tons of experiments, **the experiments came before the formulas**. It was one of the first fundamental forces we discovered in modern science, but we don't know how to do more than three body gravitational problems without supercomputers and we don't know how to quantize gravity...yet.",
"You cannot prove laws. You can only test them over and over again and fail to find any deviation. We might find a counterexample tomorrow - who knows!\n\nNewton based his laws on previous observations, more measurements were done to test his laws, they agreed with predictions, and over time people accepted the laws.\n\n----\n\nActually, we did find counterexamples already. More precise measurements found that the second law is not exact. Relativity could explain the observed deviations and it replaced Newtonian mechanics as more accurate theory. These deviations are important for things moving fast or if you need an extremely high precision. Newton's laws are still used in areas where they are good approximations - for building a house, for example.\n\n",
"Fun fact: Newton didn't call his laws \"laws\" he called them axioms. The latin title is. \"Axiomates sive leges motes\".\nFrom the wikipedia page about axioms:\n > To axiomatize a system of knowledge is to show that its claims can be derived from a small, well-understood set of sentences (the axioms).\n\nBasically he set up his 3 axioms to form a logical basis for all of physics. But the 3 axioms themself cannot be proven but have to be taken for granted. "
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208tqk | what causes the brain to short circuit sometimes when staring / thinking about a word that causes it to feel completely alien to you? | For example right now the word "From" has been bothering me and I've been saying it pronounced like "frahm," even though I know the real pronunciation. Is there a term or study for this weird little phenomenon, or is it just a random human quirk? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/208tqk/eli5_what_causes_the_brain_to_short_circuit/ | {
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"_URL_0_\n\nRepeated stimulation tends to cause reactive desensitization, which is useful in other contexts to keep you from feeling the clothes you are wearing rubbing on you constantly, or perpetually tasting your saliva."
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1rqeoi | What effect did the Napoleonic Wars have on French colonies controlled by Britain? | More specifically, what were the reactions of Quebec and Acadia, did they want independence? Did/why didn't they consider fighting with America in the war of 1812? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1rqeoi/what_effect_did_the_napoleonic_wars_have_on/ | {
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"Acadia had been French until 1710 when it was conquered by Britain during Queen Anne's war. The British were worried about the loyalty of the Acadians in subsequent wars, and finally expelled them from Acadia in 1755, when circa 7,000 Acadians were deported. After this, there was little remaining French population or heritage in Acadia.\n\nMany of the people who replaced the departed Acadians were from New England, and some of this population formed a sizable minority in favor of Independence from Britain during the American Revolution. They tried and failed to take Fort Cumberland and move some or all of the Nova Scotia colony into the Revolutionary camp.\n\nBy the war of 1812, however, the demographics of Nova Scotia and New Brunswick had changed. 20,000 British Empire loyalists fled the US during and after the Revolution to settle in Nova Scotia and New Brunswick. This made the overwhelming majority of the population Loyalist, with no interest in joining the Americans in the War of 1812.\n\nSource: _URL_0_\n\n",
"I'm not an expert on Acadia, but I'll answer why Quebec did not turn on Britain during the War of Independence/War of 1812. The first thing that you have to remember is that by the 1780s, many Quebecois did not think of themselves as French, just as many Americans did not think of themselves as British. The Quebecois were in no real rush to restore French rule over New France. The other thing was that Britain had ingratiated themselves with most Quebecois after the passing of the Quebec Act in 1774. the Quebec Act almost doubled the size of Quebec, ensured the free practice of Catholicism, and ensured that Quebec would retain its civil law code (which it still does today!). During the War of Independence, the Quebecois felt that the British would be more accepting than the Americans of their culture. During the War of 1812, the reasoning was still more or less the same."
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2w1c1v | if we are not supposed to generalize a group based on the actions of a few members of that group, why are all white people held responsible for slavery? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2w1c1v/eli5_if_we_are_not_supposed_to_generalize_a_group/ | {
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"You're currently generalizing the group consisting of people in general based on the actions of the few people who hold white people responsible.",
"Because black people in general are much more racist than whites, and they know they can use this as an advantage because whites allow it. ",
"Family came from Ireland in 1920s. Been called a slave owning white nigga before",
"Because excuse making lets individuals off the hook for their own failings, and deflects criticism away from the troubled community by assigning blame to an outside group.\n\nIn other words, it's easier to say \"black people are overrepresented in prison because the system is racist\" (it's cultural fallout from a history of slavery) than to say \"there is a problem in the black community with criminal behavior being tolerated and normalized.\" Both statements acknowledge the issue, but in the first one the problem is somebody else's to solve.",
"I don't understand - all white people aren't held responsible for slavery. And held responsible by whom?",
"Can the OP give specific examples for why they feel blamed for slavery? I think the OP might be confusing \"white privilege\" for \"being responsible for slavery\". For more on white privilege, read wikipedia's article on the subject or read this essay: _URL_0_\n",
"They're not. They're just asked to acknowledge and challenge the ways that they unfairly benefit from a systemic historically rooted in inequality that continues to influence society and its members today. "
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1xrnx7 | How deeply ingrained were the ways of Bushido in Japanese Warrior culture and when was it considered to be phased out? | We're currently starting a unit on Japan during the Tokugawa shogunate and the practice of Bushido was only glossed over. I'd like to know more about it, as in, how it was practiced, what it entailed for samurai warriors, and when the practice seemed to end. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1xrnx7/how_deeply_ingrained_were_the_ways_of_bushido_in/ | {
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"If anything, the idea of Bushido experienced tremendous growth in the Edo period. Bushido became one of the ideas that would be used to develop an idea of 'Japaneseness,' or a Japanese national identity following the Meiji reformation. It is important to understand that in many ways Bushido was an invented tradition. Its existence served to benefit the daimyo (feudal lords) by suggesting that samurai must be loyal retainers. Later, it was taken up in the process of identity-formation in the kokugaku school. Bushido, Nativist Shinto, mono no aware, etc, were all used to construct a modern Japanese identity. \n\nYou can think of the idea of samurai in the same way. Samurai became a symbol for Japan only after the samurai class had been systematically dismantled by the Meiji government. For example, the defining book on Bushido was written by Nitobe Inazo in English, for a Western audience. Inazo, like many Meiji thinkers, sought to define Japanese identity.\n\nAs for sources, I'm not really claiming anything unique here; this is all very general knowledge. You might want to look up the kokugaku school, or, if you are interested in Bushido specifically, read Inazo's somewhat ridiculous text, Bushido: The Soul of Japan; just keep in mind that Inazo's text is not taken seriously by anyone and is an example of history-making. \n\nFor a very good introduction to Japan, I sincerely recommend Tessa Morris-Suzuki's \"Re-Inventing Japan: Time, Space, Nation\""
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5n6qzn | How often would samurai commit seppuku | While reading James Clavell's Shõgun I wondered how quickly samurai would be willing to commit seppuku. As described in the book (which is a great read so far), the samurai would perform the ritual at the slightest opportunity. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5n6qzn/how_often_would_samurai_commit_seppuku/ | {
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"This really depends on the time frame you have in mind, since this practice changed quite a bit over the centuries. The earliest records of this specific type of suicide were in the final years of the Heian Period (794–1185) by Minamoto no Tametomo (1170) and Minamoto no Yorimasa (1180). It became more frequent over the following centuries and during the Muromachi period (1336–1573) it was already a very common practice. At this point, any samurai would be willing to do it, in case his lord demanded. It was the main form of execution of the time for the nobility (the samurai). Instead of being condemned to be hang or beheaded, a samurai would've simply been commanded by his lord to take his own life.\n\nDuring the Edo period (1603–1868) it became highly ritualized, involving assistants, a specific type of clothing, a last meal, a last cup of sake and the writing of a death poem. It also became a form of judicial punishment, so some people were sentenced to commit seppuku, although this was abolished in 1873. With the Meiji restoration (1868) and the abolishment of the samurai class, the practice fell into disuse, although some people have still done it since then, like the famous japanese author and poet Yukio Mishima in 1970 and the japanese judoka Isao Inokuma in 2001.",
"See [this thread](_URL_1_) and [this thread](_URL_2_) and [this thread](_URL_0_)\n\nI haven't read the popular novel. But no a samurai wouldn't be willing to commit seppuku at the slightest opportunity. While there were non-punishment reasons for seppuku, by far the most common was as a death sentence, or if the samurai knew he was going to be handed one anyway. The samurai's dead. Seppuku just allow him to separate himself from common criminals or traitors who got beheaded/crucified, and maybe as a final gamble as part of sentencing/negotiation to save the lives of his other clan members."
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28wd5j | why do internal combustion engines produce different torque/power at different rpms? | And why is this different for electric motors? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/28wd5j/eli5_why_do_internal_combustion_engines_produce/ | {
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"If you make air flow faster through a longer path, it will develop turbulence. This causes the air to expand as it flows, you get less air into the cylinders. \n\nMore restriction = less air, less fuel, less push, less torque.\n\nBUT\n\nIf you make air flow faster through a longer path, it will also develop momentum. When the intake valve closes, air backs up behind it producing a pocket of higher pressure. If the intake valve opens before this high pressure starts to backflow, it will get an extra burst of air.\n\nMore momentum = more air, more fuel, more push, more torque.\n\nWhich effect dominates depends on engine speed. \n\nGet rid of restriction, and you'll make an engine that doesn't pull as well at low speed. Tune for low-end torque and you'll lose high-end power. Improving both at the same time is difficult.\n\nPower is simply torque * rpm. (Times the conversion factor of 1HP / 5252(ft-lb * RPM)) Different torque, different power. \n"
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11mvns | Why do we have a dozen? Why do we need another word for 12 items? | Is it because of Sumerian math? That is what I am currently believing, am I right? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/11mvns/why_do_we_have_a_dozen_why_do_we_need_another/ | {
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"It's not just the Sumerians. Multiples of twelve have always been useful because they can be divided into so many even units. So we still have time based on multiples of twelve, many people still use measurements based on the 12-inch foot, and a dozen and a gross still have special words in the English language.",
"Answering this question completely would have to take into account a couple fields, and I'm not certain r/AskHistorians is the best place for any of them.\n\nOur English word for dozen derives from the French word *douze* meaning twelve and the suffix *-aine* referring to a collective unit. Thus, *douzaine* refers to a group of 12 things, *treizaine* to a group of 13, *centaine* to a group of 100, etc.\n\nAs to why English has \"dozen\" and not *trezen and *cenzen, or rather why early English speaking cultures felt a word describing twelve units of something was more useful than than a word describing thirteen of something (although we do have the term \"baker's dozen\", referring to 13 of something) and a word describing 100 of something (although we have, for example, the word century to describe 100 years), that leads naturally into the greater question of why 12 (and other numbers) were so especially relevant to various cultures. 12 has a lot of divisors, but whether or not that mathematical property has any relation to its importance in the religious and mythological discourse of various cultures is not something I'm qualified to discuss.\n\nI don't know of any direct descent-type relationship that lead from 12's (or, more generally, 60's) importance in Sumerian mathematics to 12's prominence in the English language. If any such sort of relationship exists at all, I might speculate that whatever inspired the ancestors of one culture happened to also inspire the ancestors of the other, but an anthropologist would be a better person to ask.\n\nEDIT: forgot a word"
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d8vi25 | why are there unique hats for different professions, such as a painters hat or chefs hat? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/d8vi25/eli5_why_are_there_unique_hats_for_different/ | {
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"Chefs hats (think the big white one with all the folds) started in France, you traditionally earned a gold for every technique of cooking eggs. An apprentice chef would wear a floppy “toque” until they started mastering techniques. Current day you’ll see a lot of skull-caps, worn to keep hair contained with a cool-vent top to promote air circulation because it easily gets to 120+*F in restaurant kitchens depending on where your restaurant is located. \n\nSource: am a chef therefore only knowledgeable on those hats",
"Read this interesting kids book on how Stetson invented the cowboy hat. Basically it keeps sun off and when it rains it pours the rain out front and back. It was ten gallons because I think it held water too.\n\nA welder wears a cotton skull cap thing with a small cotton bill because of the welding shield that is constant raised and lowered and for protection.\n\nBaseball cap keeps the sun out of your face.\n\nPainter's cap is paper and disposable. It keeps paint out of your hair and can be thrown out when too much paint is on it.\n\nConstruction hard hat for protection. \n\nA helmet for safety.\n\nA beekeeper hat with netting do you don't get stung by bees.\n\nIs that a good start?",
"Some are just fancy and part of a tradition, like those little ones that grocery store, pharmacy, candy shop or milkmen wore.\n\nOthers (almost certainly all hard hats) are associated with their professions because it's just practical and safe. Construction workers have hard hats in case things fall on them, or if they're getting up after bending underneath a beam. Foresters are much the same except they have full-brims to keep pinecones and scruff from falling down their jackets in the back of the neck.\n\nSlouch hats, fishermen's hats, those Asian sorta-cone-shaped hats are all to keep the sun/rain off in otherwise normal outdoor conditions.",
"The simple answer is usually necessity. Sure, some fashion involved, but, construction hat? It was developed as a good way to protect against falling objects. Painters hat? Disposable (frequently gets dirty with paint) and easy, cowboy hat kept the sun and rain out of their faces. Fashion comes into it, when someone is trying to address the need. For instance, a cowboy hat keeps the sun and rain out of ones face, but, it's not tight fitting. It would be next to useless when running, or sliding in baseball. A tighter fit, smaller hat that doesn't get in the way was developed to fit the need, with its own style. Style and function people liked it, and it caught on",
"Flat Caps were used by Nightsoilman because it was easier to balance a bucket on a flat cap.\n\nAustralian military slouch hats keep the sun off but also could be pinned up on the side of the dominant eye for sighting rifles.",
"and what about traditional nursing caps?",
"The nuns at st. Vincent's (Jacksonville, FL) had sick ones that I think were supposed to look like birds flying. I meant awesome..",
"Side note, I believe it wasn't until well into the 20th century that hat-wearing stopped being the default. In most of the Western world, it used to be that when you went outside, you wore a hat, period. There's old photos of street urchins wearing miserable rags instead of shoes, and they've all got battered, hand-me-down hats. Chaingang prisoners in stripey suits, the same.\n\nA lot of job-specific hats are from a time when every uniform came with a hat, for the same reason it came with pants and a shirt. The hat became a symbol, and remained even as the rest of the uniform changed.",
"What kind of hat does a hat maker wear? Cause I want that. It’s like asking a chef what’s a good restaurant",
"At least in the US, firemen’s helmets, similar to cowboy hats are shaped with a long brim so boiling water rolls off the back, away from the neck when making interior attacks. The front shields are unit identifiers so you know who is who, and color can indicate rank or, in the case of some places like San Francisco, the type of apparatus.",
"When my mom earned her RN back in 1961 they were given a specific hat at graduation. RNs wore the hats so patients would automatically know who was an actual registered nurse and who was among the army of support positions like nursing assistants and physical therapists. Somewhere along the way they stopped wearing hats, and today you often don't know who you're talking. They all wear name tags that has their name followed by an alphabet of certifications or degrees. Even nursing assistants have an alphabet of certifications after their name. So unless you're hospital savvy on what the alphabets mean, most people are clueless about whether they're talking to a nursing assistant, an LVN, an RN, a PA, or an MD, not to mention all the other respiratory therapist, physical therapist, phlebotomist etc alphabets that may appear. Once upon a time it was easy to spot your registered nurse on the floor in a hospital."
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7putbw | how do the internet clocks that our computers sync to stay so accurate? | Since a majority of the computers in the world are syncing their clocks to the internet through services like _URL_0_, _URL_1_, etc. how do those services maintain the time so accurately when clocks around my house lose minutes over time? Is it possible that the "internet time" could be wrong? Same thing goes for phone services like there used to be a number my parents called when I was a kid to get the time to set our clocks. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/7putbw/eli5_how_do_the_internet_clocks_that_our/ | {
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"In the US they are very likely updating their clock according to the time maintained by the National Institute of Standards and Technology, who have a number of super-accurate atomic clocks.",
"The short answer is better clocks. Nowadays that \"better clock\" is the [atomic clock](_URL_0_).\n\nMechanical clocks drift because either the devices degrade over time, or were manufactured with imperfections.\n\nOn the other hand, every single atom is identical and doesn't change over time. So if you can measure the vibration of atoms, you can keep time at exactly the pace of other atomic clocks and never get fast or slow.\n\nYou don't need to _build_ an atomic clock to have access to one -- the GPS satellites carry atomic clocks and constantly beam the current time down to earth. That means you can just listen to the sky from anywhere on earth and you can get a very accurate, synchronized time.\n\nModern clock synchronization often uses a mix of atomic clocks on the ground and the signals from the GPS satellites.",
"Really really good clocks. \n\nUTC is the common standard for civil time, and is in turn based off International Atomic Time (TIA), with the difference being that UTC adds in leap seconds when needed (basically UTC is exactly 37 seconds behind TIA). \n\nTIA meanwhile is the weighted average of some 400 atomic clocks located around the world. These clock can be stupendously accurate, the losing or gaining less than a second ever million years, and some are even better than that. These atomic clocks are compared against one another and the results are usually published monthly which then sets the standard. \n\nFrom there various national agencies synchronize their atomic clocks to that time, usually keeping them within a few nanoseconds of one another, and they broadcast the time in some way. For something you can literally listen to, the BBC still broadcasts the pips to mark the start of the hour, which is based off an based off an atomic clock in the basement of Broadcasting House and synchronized to the MSF time signal broadcast by the National Physical Laboratory . This is fairly redundant today, but if you've ever heard [this](_URL_0_) on a bbc broadcast, that's why. \n\nNetwork Time Protocol is how computers keep synchronized. You computer talks to a server that tells it the time, and those servers are split into strata based off where they get their time from. Stratum 0 is the most accurate, and will be things like atomic clocks, GPS clocks and so on. Stratum 1 tends to be primary time servers, and they'll synchronize as best as possible to Stratum 0 clocks and also cross check with each other. Stratum 2, then synchronizes to Stratum 1, Stratum 3 to Stratum 2 and so on down the line. The further down they go, the less accurate you can expect to clock to be, although the entire system is designed to try to minimize the total round trip time to keep this as small as possible. \n\nSo because all (internet connected anyways) clocks are automatically synchronizing to more accurate clocks, we can usually keep things like your computer accurate to within a millisecond or so without much hassle. The clock in your house meanwhile is on it own, so if it loses time, you need to go synchronize it yourself instead of having it self correct on a regular basis. "
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143mix | If I get a cold and then get cured, does that prevent me from catching another cold for some time ? | Or is it just multiple strands of rhino viruses running around waiting to hit me after one has been cured ? I've never had 2 colds one after another and was wondering if it's luck or an immune defense . | askscience | http://www.reddit.com/r/askscience/comments/143mix/if_i_get_a_cold_and_then_get_cured_does_that/ | {
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"There are a large number of strains of rhino virus, as well as other viruses which cause the common cold, coronaviruses for example.\n\nNow adaptive immunity has provided protection against the current infection, it still takes a period of 3 weeks before the immune system has prepared to mount a rapid response, so this immunity may not necessarily even provide protection from reinfection with the same pathogen.\n\nOn top of this the damage caused to tissues, and the immune response, as a result of the first infection put you at risk for infection as a result of the destruction or dysfunction of innate immune defenses\n\nall in all this puts you at a greater risk for a new infection, for example the flu or pneumonia, or reinfection with the same pathogen after an infection."
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1obmxi | What colour would water on Mars be- red or blue? | If you were, say, looking out across some vast lake on Mars, what colour would the water be? Would it appear red or blue?
Perhaps it would be reflecting the reddish colour of the martian sky? Or maybe bits of iron oxide in the water, that would make it appear red? Or maybe it'll just be blue?
I was just wondering, because I saw an image like [this](_URL_0_) and wondered how accurate it was.
Thanks! | askscience | http://www.reddit.com/r/askscience/comments/1obmxi/what_colour_would_water_on_mars_be_red_or_blue/ | {
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"On reading this article: _URL_0_ it seems that water is intrinsically blue the deeper it goes - shallower parts might appear brownish red due to the dirt beneath and the sky above, but the water would still be blue (although it would reflect the sky somewhat, I'm not sure how much. - \n\n\" Clean water appears blue in white-tiled swimming pools as well as in indoor pools where there is no blue sky to be reflected. The deeper the pool, the bluer the water.\" ",
"much like the early oceans of earth, they'd be heavily saturated with iron oxide. they would be nearly blood red near shore, and a deep maroon color in the deeper areas.\n\non earth, the favorable conditions allowed most of the iron in our oceans to settle and lay a layer of it down [across the entire face of the earth](_URL_0_). interestingly enough, most of the worlds harvested iron deposits are from this layer.\n\nthe issue with Martian oceans is that because the seas would evaporate fairly quickly, the water would saturate with iron oxide. once a substance reaches a certain saturation point, it becomes more like a non-Newtonian fluid. it's quite possible that this is what happened sometime in the past 2 billion years on mars, thus giving rise to the extremely waterdense soils that curiosity recently found.\n\nif mars had a sustainable ocean today, though, the shear amount of iron-oxide containing runoff would resupply what was lost by it's gradual settling on the ocean floor, and thus the oceans would be thick with rust and appear extremely dark red.",
"I actually did a fair amount of research on this for a novel I was writing, so this question is cool for me! \n\nLet me cover some foundational explanation, but if you want to skip right to the end, feel free.\n\nThe first thing to point out is that what we perceive as color is what is known as the \"visible spectrum of light\": _URL_3_\n(More info from Wiki's page [here](_URL_0_) )\n\nWe see a very, very narrow band of \"light\". This thing we call \"light\" is actually a segment of the electromagnetic spectrum, which covers pretty much every energy known to man. Our eyes can perceive to ~450nm (dark blue) to about 650-700nm (dark red). As an aside, that \"darkness\" is not actually that the color is closer to black, but that most of the light at 400nm and 700nm is not accessible to our eyes. Beyond 400nm you get ultraviolet light (UV rays that your sunglasses and car windows block), and beyond 700nm you get microwave and radio waves (of which you know many uses).\n\nWhy does this matter? Because we [know the electromagnetic absorption of water](_URL_2_). \n\nSo, a bit of an understanding on that... Why do leaves look green to us in the summer, and then red to us in the fall? Do they \"change\" color? Actually, not at all. You've heard of \"chlorophyll\", which is how plants turn sunlight into energy. Well, how this works is through photosynthesis. The plant literally absorbs the light from ~400-500nm and from ~600-700nm (dependent on plant). Source: [Wiki](_URL_1_). If you look at your visible light spectrum, this leaves us only the 500-600nm range to work with. What color do we have in that? The same color we see when we look at plants, green/yellow. Plants aren't green, but they \"eat\" all the light except for the green, which is all that is left for us to see. In the fall, when they stop absorbing the red light, they begin to look more yellow and then red.\n\nSo, the original question, \"What color would water be on Mars?\". As above, we know what the electromagnetic absorption of water is. Water absorbs the most light near the microwave and infrared sections (that is to say, \"red\", or near the 700nm area), which is also how microwaves work (exciting water molecules deep inside the food). As the wavelength of light decreases toward 400nm, water absorbs less and less of the light, leaving more and more of that light available for us to see. Thus, the light remaining would be mostly blue to us. Water is water is water, and water is blue. Mars' atmosphere may have some effect on the visible light reaching the water to be reflected, but I believe it's too thin to have much of an effect on electromagnetic radiation.\n\nTL;DR: Water on Mars would be blue, because that's what color all H2O water shows up as.*\n\n*= As /u/brett6781 said, contaminants can also change the color of water, but the water itself would be blue. Deep oceans would, presumably, look deep blue as on Earth."
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3jfqn4 | why does hard fat (or visceral fat) occur in some people's belly, especially in alcoholics? | There are probably answers out there, but when I Google the topic I get barrages of crappy belly fat "cures". I don't wanna know how to get rid of it, I just want to know how it differs from soft belly fat. Is it just more compressed? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/3jfqn4/eli5_why_does_hard_fat_or_visceral_fat_occur_in/ | {
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"Alcoholics get big, hard bellies not from fat, but from fluid buildup called ascities. Heavy alcohol use damages your liver, and that liver damage causes fluid to back up into the belly, causing it to swell up and get firm like a water balloon. Someone who has ascities needs to see a doctor"
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2bzbey | Did bombing raids during the WWII only target military targets or were there also intentional civilian targets being bombed? | As title says. Were there planned bombing raids to civilian targets or were civilian casualties always collateral damage? And if so why did they target civilians? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2bzbey/did_bombing_raids_during_the_wwii_only_target/ | {
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"Before WWII, Prime Minister Neville Chamberlain made a speech declaring bombing cilvilians, \"against international law to bomb civilians as such and to make deliberate attacks on the civilian population\".\nDurring WWII, however, there was a movement away from this, starting with Churchill, in response to Germany's bombing of London. It was at this point Churchill articulated the need for, “absolutely devastating exterminating attack by very heavy bombers from this country upon the Nazi homeland.” Also affecting this decision was military officials realizing that dropping bombs from aircraft were far too inaccurate to target specific things, such as factories, etc.\n\nIn 1942, under the command of Sir Arthur \"Bomber\" Harris, The Royal Air Force switched to destroying enemy civilian morale. In the summer of '42, the U.S. joined in on Britain's strategic bombing campaign. \n\nIn 1945, the U.S. extender their policy to targeting Japan's civilians. In one night, with their fire bombing of Tokyo, they killed 80,000 civilians, more than the casualties of the Atomic Bomb dropping on Nagasaki. \nSource: _URL_0_",
"So far as \"why target civilians\", strategic raids in World War I such as German Zeppelins and Gothas and Britain's Independent Force nominally targeted military facilities but were highly imprecise, civilian casualties having a significant effect on morale. As technology advanced, allowing greater payloads to be carried, the possibility of completely defeating an opponent through air power, destroying their will to fight by targeting civilians, was postulated in works such as Giuloi Douhet's *The Command of the Air*, first published in 1921:\n\n\"There will be no distinction any longer between soldiers and civilians. The defences on land and sea will no longer serve to protect the country behind them; nor can victory on land or sea protect the people from enemy aerial attacks\"\n\n\"How could a country go on living and working under this constant threat, oppressed by the nightmare of imminent destruction and death?\"\n\nBritish Prime Minister Stanley Baldwin gave a famous speech in 1932:\n\n\"I think it is well also for the man in the street to realise that there is no power on earth that can protect him from being bombed. Whatever people may tell him, the bomber will always get through, The only defence is in offence, which means that you have to kill more women and children more quickly than the enemy if you want to save yourselves...If the conscience of the young men should ever come to feel, with regard to this one instrument [bombing] that it is evil and should go, the thing will be done; but if they do not feel like that – well, as I say, the future is in their hands. But when the next war comes, and European civilisation is wiped out, as it will be, and by no force more than that force, then do not let them lay blame on the old men. Let them remember that they, principally, or they alone, are responsible for the terrors that have fallen upon the earth\" \n\nWith revulsion at the prospect of unrestricted bombing, and military doubt over whether bombing alone could secure such a victory, no air force at the start of World War II was really equipped or intended for such a campaign, and in most cases care was taken to stress that civilians were not being specifically targeted, at least as far as official records went, despite the inevitable results of bombing military or industrial targets in cities. James Coram writes: \"German legal scholars of the 1930s carefully worked out guidelines for what type of bombing was permissible under international law. While direct attacks against civilians were ruled out as \"terror bombing\", the concept of attacking vital war industries—and probable heavy civilian casualties and breakdown of civilian morale—was ruled as acceptable.\"\n\nBased on the results of Luftwaffe attacks on Britain in 1940-41, Lord Cherwell, scientific advisor to Churchill, wrote a memorandum in 1942:\n\n\"Careful analysis of the effects of raids on Birmingham, Hull and elsewhere have shown that, on the average, one ton of bombs dropped on a built-up area demolishes 20-40 dwellings and turns 100-200 people out of house and home. \n\n(...)\n\nIn 1938 over 22 million Germans lived in fifty-eight towns of over 100,000 inhabitants, which, with modern equipment, should be easy to find and hit. Our forecast output of heavy bombers (including Wellingtons) between now and the middle of 1943 is about 10,000. If even half the total load of 10,000 bombers were dropped on the built-up areas of these fifty-eight German towns, the great majority of their inhabitants (about one-third of the German population) would be turned out of house and home.\n\nInvestigation seems to show that having one's house demolished is most damaging to morale. People seem to mind it more than having their friends or even relatives killed. At Hull, signs of strain were evident, though only one-tenth of the houses were demolished. On the above figures we should be able to do ten times as much harm to each of the fifty-eight principal German towns. There seems little doubt that this would break the spirit of the people.\"\n\nThis followed the Butt Report of 1941, which concluded that RAF bombing efforts up to that point (aiming at specific military or industrial targets) had been highly inaccurate, with only one in three aircraft getting within five miles of their target. With no realistic prospect of being able to stage a landing on the European mainland, this resulted in the clearest targeting of civilians, the Bomber Command campaign of 1942 onwards with the highly euphemistic policy of \"area bombing\" to \"dehouse\" workers, the intention being the destruction of cities. There is fierce debate over the morality and effectiveness of the campaign; see for example Adam Tooze *The Wages of Destruction*, Richard Overy *The Bombing War: Europe 1939‑1945*.\n\nAs the RAF campaign escalated, the Luftwaffe abandoned even the pretence of military targets in seeking retaliation, though with more limited resources. *Luftwaffe Fighter-Bombers Over Britain: The Tip and Run Campaign, 1942-43* describes, amongst attacks on shipping and coastal targets, \"Terrorangriff\", indiscriminate terror raids, such as a combat report from a raid on London in January 1943:\n\n\"3) Effect of the attack: \nVery good grouping of hits in blocks of flats and crowds of people, violent detonations. Collapse of multistorey houses observed. Busy streets, obviously there was no air raid warning before the attack. High losses among civilian population probably.\n\n(...)\n\nThe effect of the attack against houses and live targets has to be described as good.\"\n\nLater V1 and V2 attacks were also indiscriminate in nature.\n\nIn general USAAF raids over Europe had specific military or industrial targets, though with massive bomber formations and difficulty in targeting, especially in less that ideal conditions, the end result could be similar to area bombing. In the Pacific, the firebombing of Tokyo has been mentioned, and of course the atomic bombs on Hiroshima and Nagasaki.",
"That is a very difficult question to answer in terms of the European Theater of war. In general, with the exceptions of [Guernica](_URL_0_) and [Rotterdam](_URL_1_) (and probably [Poland](_URL_3_)), both the Luftwaffe and RAF took great pains to not attack each others' cities.\n\nThat changed with the London Blitz, which was the result of an accidental release of bombs on London during the night of 23/24 August 1940. The next night, the RAF bomber Berlin and from then on, the Germans conducted the [London Blitz](_URL_8_).\n\nThe RAF switched tactics in February 1942 from attacking individual targets in Germany to attacking areas, in response to the [Butt report](_URL_2_). Most people see this is attacking civilians, however, in every case an industrial area or railway yards. This was due to shortcomings in the RAF night bombing campaign and increasing losses. \n\nThe [Area bombing directive](_URL_5_) and the [Casablanca directive](_URL_4_) which specify targets do not explicitly civilian areas as targets, but the Chief of the Air Staff, [Charles Portal](_URL_9_) did note that urban areas would be heavily damaged due to the nature of the targets. [Sir Arthur Harris](_URL_10_) was quite outspoken and did say publicly that his job was to \"kill Germans\" which was inflammatory and did damage both his reputation and the reputation of his crews.\n\nIn short, Europe was complicated: German civilians were not deliberately targeted, but callous disregard was shown to their presence, as illustrated by the raids on [Hamburg](_URL_6_) and [Dresden](_URL_7_). "
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dbscgx | can ants carry diseases (not poison) to human beings? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/dbscgx/eli5_can_ants_carry_diseases_not_poison_to_human/ | {
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"Theoretically possible, but as far as I know they are not a vector for any well known disease.",
"Diseases are transmitted to humans via vectors (Arthropods, specifically fleas, tick, and mosquitos) which can transmit in one of two ways - mechanical or biological transmission. Mechanical transmission is when the pathogen on its feet. Biological transmission is when the pathogen reproduces or undergoes some form of reproductive change, then is transmitted to people via bites or feces. \n\nAnts do transmit disease but the prevalence is not nearly as high as in mosquitos or ticks. Usually ants are vectors of transmission through mechanical transmission. The main cause of ant related disease is through bacterial and fungal infections in countries that are less hygienic. Usually these diseases present themselves through a secondary infection - an infection which normally would not infect someone but now does given a weaken immune system for example. \n\nSource - I’m a microbiology major in my senior year",
"Not specifically for humans, but if you want to read about something really interesting, try the life cycle of [Dicrocoelium dendriticum] (_URL_0_), which goes between snails, ants, and sheep. One of the more fascinating parasite life cycles."
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2h6sze | how does esp and other sport networks come up with these obscure stats? | As in a baseball player had 5 hits with 4 being doubles and one single that the left fielder had an error for the first time since 1882 | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2h6sze/eli5_how_does_esp_and_other_sport_networks_come/ | {
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"They have computer programs that do it. All the stats are recorded and maintained by either the league or the media themselves (usually both), so the data is all there. It's just a question of writing a computer program that pieces together stats out of that data, which isn't that hard to do: computers don't mind just combing through spreadsheets for hours.\n\nThe programs themselves aren't simple, but the basic idea is that you have the program constantly look for patterns of data and learn to flag it as \"maybe this is interesting (it doesn't actually know).\" So, since it's been keeping track, it knows that it hasn't seen the pattern of \"lefty with 4 doubles, a single, and one error\" since 1882, so that's rare enough to potentially be interesting.\n\nedit: I should add that it's a person who actually chooses what goes on screen. The computer just gives them a bunch of options.",
"There are companies that specialize in doing nothing but generating sports statistics. The most popular one is called [Stats Inc.](_URL_0_)",
"The store all the raw data, down to every at bat, every pitch, every fly ball and force out, in a database.\n\nThen they have a query language, where they can say things like \"select Player where Game.Hits > = 5 and Game.Doubles > = 4 and Game.Fielder.LF.Errors > = 1 and Game.Data > = 1882\" and get a list of of everything that matches that criteria. "
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z5s9b | why is the euro collapsing? it seems like such a good idea for all of europe to share a currency. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/z5s9b/why_is_the_euro_collapsing_it_seems_like_such_a/ | {
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"A single currency allows for more efficient trade, but removes monetary policy from the individual nations and gives it to the bank of the entire EuroZone.\n\nAs everyone is using and borrowing the same currency, when some countries *cough Greece cough* lie about their finances to get in and then do a terrible job on their own economy, it hurts their currency which is also the currency of everyone else in the Eurozone. This makes it harder for other countries to borrow money, which hurts their economies, and makes it even HARDER for the others (and those initial countries) to borrow money, etc. etc.",
"I'm no super expert on this but my father is an accountant and this what I can remember of what he told me.\n\nThe idea of the euro was that only countries with strong enough economies could join but if they upheld those strict rules only Germany would have joined so they let in a bunch of countries with terrible economies. What this means is that you have a huge imbalance in economy strength between the countries in the euro. What this means is that when those weak countries hit hard times, make stupid decisions and go bankrupt the euro is in danger of devaluing, so people lose confidence in the currency so the currency devalues (yes this is fucked up logic but that is how it works) the only thing keeping the euro up is people confidence in Germany and their confidence that weak counties will recover. So if any weak country collapses the euro will collapse.\n\nHaving a lot of counties on 1 currency is unbelievably stupid, it works well in times of prosperity because it allows countries (especially weak countries) to trade and grow much better however in times of recession everything falls apart like a stack of cards (the EU and euro was designed to strengthen Europe economy so it could compete with china and america but actually weakened the economy) \n\nThe only country to actually benefit from the euro was Germany as it allowed them to make a lot more money from its exports and is refusing to bail out countries like Greece that it could easily afford to bail out.\n\nThis isn't exactly a good answer but its hard to explain over Reddit as it is such a complex issue. If you want to know more then you have to learn about the subject and Google it",
"let's say you just graduated and you're now sharing an apartment with you best buddies from college.\n\neveryone is different and has different jobs and obviously a different income. now lets say that you're super smart and super ambitious. and you work in finance. every month you rake in the cash and you are rich as fuck.\n\nnow lets say some of your other bum-ass friends aren't like you and they make maybe 10k a year or even less. barely enough to scrape by. not only that though, they drink, they gamble, and they just fucking lie about their finances.\n\nnow imagine having to pay rent. because you adopted a new \"always-pay-rent-no-matter-what\" rule, you end up fronting the bill when your housemates cannot make ends meet. \n\nobviously this will strain your own wallet and is just all around frustrating. \n\nyou are germany and your housemates are the other countries of europe. GTFO and find a new house bro",
"Right now Mommy and Daddy give you and your many and brothers and sisters a combined allowance. Based on whether you all saved that money and spent it on good things like crayons for school, or whether you wasted it on bad things like candy, mommy and daddy give you all more or less allowance next time.\n\nNow imagine a you and a few of the other kids were very responsible with your money, and didn't have any candy at all so that you could have more allowance, while some kids ate lots of candy and had all the fun they wanted with the money. Since you all shared the responsibility of keeping the amount of allowance high, their bad decisions meant that despite your hard work, the allowance does not improve like it should.\n\nDoes this sound fair to you? It's not fair to the hard working kids. That is why mommy and daddy are starting to think it might be a better idea to give you all a separate allowance, like our parents did to us when we were five :)",
"I have no real data to back up any of the things I say. If you are looking for facts, skip this.\n\nI will state them as anecdotal evidence, from the perspective of a German guy.\n\nWhen the Euro was introduced, everything got more expensive overnight. Food to clothing, the conversion to Euros was a ripoff in DM (Deutsche Mark, the former German currency), raising prices a good 50% or more.\n\nAnd ever since then, people had to eat that difference. Where did it all go? Did the fair trade make things cheaper or better for consumers? Fucking no is the answer. However, deficits in places outside of Germany certainly made out like bandits. In whose interest? Are the Germans benefiting from Greece, Spain or some other shithole being bailed out? No.\n\nBut it was beautiful! For a lot of the cost was rolled up with economic problems stemming from the situation with East Germany having joined a union that was undoubtedly going to cost a major amount of money initially. Isn't that nice how it all came together?\n\nI'm not a very paranoid person in general, but this one was clear from the get-go: fleece those who have been successful as a country and take what they have in surplus, and make rich a few selected in a move that is supposed to \"rescue\" entire countries. Only that the rescue is artificial, but the banks made a killing.\n\nI sound like kook, but look at the situation today. Who really has chips left in this game? The banks, foreign and domestic. And that's it.",
"There is no redistribution of money between countries. In America, different states have different amounts of money. Alaska is poor. New York is wealthy. The federal government taxes people, and redistributes that money in spending. New Yorkers pay a lot more than they receive, and Alaskans receive a lot more than they pay. This allows for all of us to share a currency, because even though a New York dollar would be stronger than the US dollar is, and the Alaskan dollar would be weaker, it gets balanced out by the redistribution of wealth through federal taxes and spending. \n\nNow look at Europe. There is a common currency, meaning that Germany, which would have a strong German Mark (German dollar), gets to have a weaker Euro. Greece, on the other hand, which would have a really weak Greek Drachma, has a stronger Euro. This means that Germany's healthy economy can export a ton of stuff, similarly to China, because of a relatively devalued currency. Greece on the other hand imports more than it should because of a stronger currency. This means that they get an economy that is continually getting weaker, while Germany is benefiting. This is solved in the United States by federal redistribution, but EU doesn't have that, so certain member states (Portugal, Italy, Ireland, Greece, and Spain in particular, or the PIIGS) are doing very poorly economically while others, like France and Germany, are doing comparatively very well because of the effects of a shared currency over seriously different economies.\n\nTL;DR The EU doesn't have a way to address the issues that come from different regions benefitting from, while others are hurt by, a shared currency. This means the EU can't survive indefinitely, and the recession kick-started what would have been an issue further down the road.",
"You are probably thinking \"Just like the 50 States have the Dollar, all European countries should be able to share a currency too, right?\"\n\nNo. The thing is, in the US, we're all roughly the same. Sure, some parts like Cali and NY are richer, and places like the midwest are a little poorer, but in general we all on average make close to the same amount of money, spend about the same amount, etc etc. Not to mention, all of the State Govts are roughly the same as each other, with very similar policies, as well as the Federal Govt.\n\nIn Europe, the difference between the countries is huge. Each have unique governments to each other, with lots of policies differences that vary much greater than between the 50 USA states. So take the big policies differences, as well as highly varying incomes and spending, not to mention different cultures in regards to money and the economy, and it is extremely hard to group them all together and get them on the same currency.\n\nAt least, that's my opinion. Not to mention, France, Germany and the other big governments are providing a lot of the support for the smaller countries. Yes, Cali, NY etc earn a lot more and put a lot more into the US govt than the other states do, and a lot of states take a lot of aid back, but the USA has a couple hundred years of practice. The EU has been around for 20, and didn't have the advantage of starting along with the other governments. They're stuck trying to bridge divides between lots of very different governments and countries.",
"A unified currency does not equal a unified economy.",
"In a nutshell, the primary reason behind the collapse is that while the currency is shared, each EMU country is allowed to regulate it their own way.",
"Money issued from a central bank works because the money is created and issued to all the other banks on interest, which then is loaned to the people on interest. The people have to pay back the bank they got the money from, which has to pay back the central bank. If somebody produces and sells $325k worth of VALUE of a product but only gets to keep a $300k house, they lose $25k worth of value from the product they created.\n\nWhile it doesn't sound like a bad idea on the surface to profit off of money being used as a service for people to exchange their goods (after all - somebody had to create the money, so why should they not get paid for it?), but beneath the surface, since everybody owes the money back to somebody else on interest, somebody is profiting each time by the simple act of people exchanging goods. It sucks value from the goods being produced by the entire community, and cripples the community.\n\nThis is exactly what is happening in Europe (and most other western countries) with the Euro. A system becomes created where everybody owes things to other people, so everybody is forced to work, but eventually (since all the value is being sucked from the society) more and more people can't afford to buy basic necessities and they become lower class. Since Euro is now a system that many countries in Europe use, it is effecting the entire continent and many other continents that trade with it.",
"The question you should ask is: Is the euro collapsing? No it is not.",
"Fiat Currency. Fiat currency is backed by no commodity whether that be gold, silver, uranium, oil, or whatever. When it is not backed by a commodity it can be inflated rapidly, and printed rapidly to cover budget deficits. Because all the countries have budget deficits in varying amounts, it is dragging other countries down with the rest. \n\nBasically the same thing happening to our currency, only its happening faster and much worse due to each nation having different national budgets.",
"Think of it this way:\n\nYou're in a rowing boat, and each person rowing is a European country. Suddenly, some of the people rowing get too tired, which means the boat starts to slow down, to make up for this the other rowers have to try harder (by bailing other countries out) This causes those rowers to tire faster, and eventually everyone is nackered.",
"The problem with the Euro is that it's being used by more than 20 different economies, and while they've synchronized their currency, they haven't synchronized their economic policies, and the cultural variance from Sweden to Greece is vast.\n\nGreece, for example, is a pretty laid back country where people, from what I understand, feel entitled to their pensions. This, combined with a history of tax evasion, and you have a country that's using the euro, not paying taxes, paying out pensions, and racking up a large amount of debt. When this system collapsed on the Greeks in 2008, it sparked what we know today as the Euro Crisis. Basically, Greece must either pay off its debts and cut back on public programs and pensions, increase taxes (neither of which it really wants to do), or default.\n\nSo why doesn't Greece just default then? Well if it does default, it'll cause a devaluing in the Greek currency and force it to trade at a lower price on the global market. That's right, the Euro. If Greece were to default, it would cause all of Europe's currency to be valued less, which would likely cause an economic collapse in Spain, Portugal, or Ireland, which would in turn cause a collapse in other countries, eventually making its way throughout Europe and likely causing another recession, of greater severity than the last.\n\nThis is why Germany has it in it's interests to continue bailing out Eurozone countries: if any of these countries were to default, Germany would be directly affected, and it could be possible that Germany would face similar issues as Spain or Italy today down the road as a result. Germany for the most part has had a smooth economic recovery thanks to smart economic organization, reducing taxes strategically, and offering aid to industry wherever it's needed.\n\n**TL;DR VERSION:** Countries in the euro use the same currency but not the same economic strategy; their cultures in regards to economics differ vastly enough so that the way they deal with day to day economics is different; no country in the Eurozone can default on their debts without causing a continental economic disaster.",
"*Why* does it seem like such a good idea? There are lots of benefits to a country controlling its own currency, rather than sharing with the rest of Europe.",
"2 words: regional imbalances",
"I heard a thing on NPR once about how uniting Europe in a currency is a much different situation than the US and our dollar.\n\nI have nothing to contribute to this thread."
]
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[],
[],
[],
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6s4k8y | Dogfights in aerial combat started out using guns rather than missiles. What happened when the rounds missed their target? | [deleted] | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6s4k8y/dogfights_in_aerial_combat_started_out_using_guns/ | {
"a_id": [
"dla9ser"
],
"score": [
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],
"text": [
"Here's a link to the top response when the same question was asked here before:\n\n_URL_0_"
]
} | [] | [] | [
[
"https://www.reddit.com/r/AskHistorians/comments/31argr/are_there_any_records_of_collateral_damage_due_to/cq01j8u/?st=j62acekt&sh=10b3df89"
]
] |
|
6we7gv | How common was blonde/red hair in Medieval England? Did it have any superstitious qualities or stereotypes associated with it? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/6we7gv/how_common_was_blondered_hair_in_medieval_england/ | {
"a_id": [
"dm84uni"
],
"score": [
2
],
"text": [
"u/sunagainstgold and I talked about the second half of your question [here](_URL_0_) (Sun's answer being part of last April Fool's \"AskHistoricalFiction\"), and I'd be happy to answer any follow-up. As for the first part, no data exists to give you an exact number, but there haven't been any large population shifts in England to cause a major change in the prevalence of red hair between then and now, as far as I know. It's possible that there's been some level of genetic drift or change, but that's mostly a scientific question, not a historical one. "
]
} | [] | [] | [
[
"https://www.reddit.com/r/AskHistorians/comments/62lvm2/comment/dfoefcg"
]
] |
||
2q8iy6 | Were there any Finns among the Vikings, especially during the raids? | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2q8iy6/were_there_any_finns_among_the_vikings_especially/ | {
"a_id": [
"cn3w2bh"
],
"score": [
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"text": [
"Short answer: Sure, probably, why not?\n\nLonger answer: We have no way of *really* knowing. Most of the sagas which concern themselves with vikings don't bother talking too much about the crew, unless they're important in some way. Finns in the sagas tend to be wizards, and specifically tend to be Sami, rather than vikings. It's not inconceivable, though, that Swedish and Norwegian vikings would have had a Finn or Sami or two on their crews, given the proximity of the people."
]
} | [] | [] | [
[]
] |
||
3cgghr | i've heard that no matter where you are in the universe, you're still equidistant from the universe's "edges" as it expands. how is this so? or am i getting this wrong? | If I'm not getting this wrong, does this mean that, going forever in one direction in the universe, one would eventually end up where they started? With the curvature of space-time and whatnot? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3cgghr/eli5_ive_heard_that_no_matter_where_you_are_in/ | {
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"text": [
"The \"edges\" of the universe are just as far as we can see, not physical edges, because the light at the edges is from the beginning of the universe and there can't be any light from before the universe.\n\nIt's like two ships on the ocean, which both see the horizon equidistant from themselves no matter where they are.",
"The current leading cosmological theories about the universe are a universe that is unbounded and infinite. There is no edge to approach, in any direction, and you would not return to where you started, but be forever further from that location. ",
"The most likely is no edge to the Universe. \n\nThere is an edge to the so-called \"visible universe\" which means the part of the Universe from which the light has had time enough to reach us. This visible Universe is roughly a sphere centered on whoever is observing, just the part of the ocean you would see on a boat would roughly describe a circle on the map, centered around the observer.",
"Don't think of the universe as a \"flat\" object that has edges. Instead, imagine yourself as a microscopic being living on an inflated balloon that is slowly expanding. No matter where you are on the balloon, you aren't any closer to an edge because there is no edge."
]
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[],
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[],
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|
p6gdb | why do central banks change interest rates? | Why do banks change interest rates? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/p6gdb/elif_why_do_central_banks_change_interest_rates/ | {
"a_id": [
"c3mw4rm"
],
"score": [
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"text": [
"Interest rates are powerful tools available with the banks to regulate the monetary policy of a country. The basic aim is to provide stability to the economy so that it does not fall apart.\n\nCentral banks can increase the interest rates, resulting in increase in borrowing cost. By doing so, they are effectively trying to reduce the supply of money in the system. This is done when the banks feel that the economy is overheating or to tame down inflation. \n\nCentral banks can also reduce interest rates reducing the cost of borrowing. Cheaper money can result in increased economic activity and thus boost growth."
]
} | [] | [] | [
[]
] |
|
s1ybu | Since a tattoo darkens one's skin, does that means it increases the tattooed area's resistance to sun damage? | askscience | http://www.reddit.com/r/askscience/comments/s1ybu/since_a_tattoo_darkens_ones_skin_does_that_means/ | {
"a_id": [
"c4afpfi"
],
"score": [
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"text": [
"No. Naturally dark skin is due to the concentration of [melanin](_URL_1_), which is a natural [photoprotectant](_URL_0_), which means it undergoes processes to prevent DNA damage. Tattoo inks are not too different from your standard industrial-standard paints, usually made out of [heavy metals](_URL_2_). They don't possess the same properties that melanin has. Even though they are both 'pigments', that word only refers to the concept of being a compound that changes the color (to our eyes) of reflected light via absorption. \n\nThe main physical difference that makes their properties and functions so difference is that melanin is a protein-derived natural pigment, and inks are typically synthetic, metal-based pigments. Some inks do come from natural sources, but this does not mean they have photoprotectant properties."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Photoprotection",
"http://en.wikipedia.org/wiki/Melanin",
"http://en.wikipedia.org/wiki/Tattoo_ink"
]
] |
||
514y5p | I am a child in the Middle Ages, what is my life like? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/514y5p/i_am_a_child_in_the_middle_ages_what_is_my_life/ | {
"a_id": [
"d79cx44"
],
"score": [
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"text": [
"A good example of this is Onfim, a 13th Century Russian boy whose writings were discovered in the mid-20th century. \n\nA brief overview of his writings can be found here: _URL_0_\n\nA child in Middle Ages Europe may or may not have had schooling, depending on the time period, locality etc. \n\nAs you can imagine, if you were born the son of serfs in Europe, such as the Holy Roman Empire, you would most likely be working the land by age 5 or 6 alongside your parents, learning the farming trade. \n\nConversely, if you were in a larger city and the son of a merchant, artisan, etc. you would have more opportunities for education - which was overseen by your local church. You would learn, primarily, the basics of reading and writing, basic math for use in money handling and counting/division, and this was primarily supplemented by the local language version of the Bible - which in the early Middle Ages was usually in Latin, and later translated to the various languages such as old French, Middle German, Aragonese, and Church Slavonic in the Eastern regions. \n\nIf you check Onfim's writings you can see that the son of a city guard/soldier ( he refers to his father as a warrior in the drawings ) at least had basic writing education. \n\nAfter basic education, you'd either be taught by your parents their trades/occupation or whomever they could secure an apprenticeship with."
]
} | [] | [] | [
[
"http://www.goldschp.net/SIG/onfim/onfim.html"
]
] |
||
s83dn | How much total data does the human genome take up? | I've looked all over the web and have heard a few different answers.
I've heard it's 800MB, 1.5GB, between 2-30TB, and 20MB.
_URL_0_
_URL_1_ | askscience | http://www.reddit.com/r/askscience/comments/s83dn/how_much_total_data_does_the_human_genome_take_up/ | {
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"The different answers come from which sections of the genome you're considering, and some uncertainty over the figures. There are about 23,000 protein-coding genes in the human genome, containing 3.2 billion base pairs and thus using about 750MB of data. (An individual's differences from the \"standard\" human genome are much smaller and could be stored as a delta of only a few megabytes, providing you had a reference for the standard somewhere.)\n\nThe complete human genome, including regulatory sequences (which turn on and off gene expression) and vast amounts of other non-coding DNA, the purpose of which is largely unknown, is much bigger - protein coding DNA accounts for only about 1.5% of the total. This would require 50GB to store.",
"The 1.5GB estimate at Wikipedia sounds right. (~800MB for the haploid genome, 23 chromosomes -- therefore ~1.5GB for all 46 chromosomes) However, it presumes a system where each base pair (of the 6.3 billion base pairs) would be coded by exactly 2 bits of data. Also it presumes that you know your DNA sequence exactly, where in reality you will only know it to a certain degree of certainty.\n\nYour genetic-future link is referring to the data produced by a gene-sequencing machine, not the actual data encoded in the genome. This machine breaks up your DNA and then uses DNA polymerase to replace one of the strands with DNA that contains a different fluorescent color. And then the machine actually takes photographs of the fluorescently labeled DNA. These photographs are what takes up 30 terabytes.\n\nThen an algorithm is used to translate the fluorescent fragments into DNA sequences. The machine uses a lot of redundancy, so every fragment of DNA gets read out an average of 30 times. To keep all that redundancy and uncertainty in the data takes 2 terabytes. To reduce the data to a likely sequence, plus a measurement of certainty for each base air, takes 90 GB. To reduce the data further, to just the most likely sequence, takes 1.5GB.\n\nThen the data can be compressed further by just including the parts that vary from a standard reference genome, and leaving out the parts that are identical to that reference genome.\n\nNote: This is just a paraphrase of various links. I've used Illumina machines in the lab before but I'm no computer programmer.",
"Carl Sagan goes through an excellent (though somewhat rough) calculation/estimate of the data in the human genome in his book \"The Dragons of Eden.\" I forgot what his answer was and couldn't find it online. He also talks about how the amount of data in our genome is at or pretty near the upper limit for how much data a genome can contain. With more and more data, bombardment from various wavelengths along the EM spectrum are more likely to corrupt that data and cause a mutation. Such mutations make that person less likely to live long enough to reproduce. What I am stumped on is why these kinds of mutations would necessarily tend to be negative when random mutation has an overall positive effect and is the mechanism of evolution. "
]
} | [] | [
"http://www.genetic-future.com/2008/06/how-much-data-is-human-genome-it.html",
"http://www.wolframalpha.com/input/?i=3.2+billion+base+pairs+*+2+bits%2Fbasepair+to+megabytes"
] | [
[],
[],
[]
] |
|
1las84 | Did Curiosity and NASA ever determine what that strange "metallic arm" object was on Mars? Why couldn't Curiosity get closer and take clearer pictures of whatever is was? | askscience | http://www.reddit.com/r/askscience/comments/1las84/did_curiosity_and_nasa_ever_determine_what_that/ | {
"a_id": [
"cbxithx"
],
"score": [
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"text": [
"It was completely driven by tabloid speculation. [Here's a bit of slightly intelligent speculation](_URL_1_), but it's still a bit outlandish. [Here are the actual two images taken by the rover: [Photo 1](_URL_2_), [Photo 2](_URL_0_). It's pretty much just an ordinary rock with a bit of lighter material catching the sun, so it doesn't really warrant further study."
]
} | [] | [] | [
[
"http://mars.jpl.nasa.gov/msl/multimedia/raw/?rawid=0173MR0926020000E1_DXXX&s=173",
"http://www.universetoday.com/99750/another-weird-shiny-thing-on-mars-2/",
"http://mars.jpl.nasa.gov/msl/multimedia/raw/?rawid=0173ML0926020000E1_DXXX&s=173"
]
] |
||
1ctcth | Shouldn't the Earth be more "leveled out" by landslides/earthquakes/erosion? | It seems that natural phenomena like landslides, earthquakes, erosion, etc. are flattening the surface of Earth at a much quicker rate than new mountains and hills are rising up. I've always been curious about the fact that over billions of years that most of the surface of our planet hasn't "leveled out" due to these types of natural occurrences, so I was hoping someone could shed some light on the subject. | askscience | http://www.reddit.com/r/askscience/comments/1ctcth/shouldnt_the_earth_be_more_leveled_out_by/ | {
"a_id": [
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"text": [
" > It seems that natural phenomena like landslides, earthquakes, erosion, etc. are flattening the surface of Earth at a much quicker rate than new mountains and hills are rising up.\n\nThere is some leveling out; contrast the 480 million year old Appalachian mountain range with the 80 million year old Rocky Mountains. However, the rate of erosion is slower than that of active mountain formation.",
"By contrast the earth is smoother than the average cue ball, mountains and all"
]
} | [] | [] | [
[],
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|
ctqao9 | why do popcorn kernels generally have either a smooth surface but are randomly shaped, or a distinct cracked surface but are usually more sphere shaped? | Help me understand lol | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/ctqao9/eli5_why_do_popcorn_kernels_generally_have_either/ | {
"a_id": [
"exo03nx",
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"text": [
"it has to do with the \"wet\" kernels. things like the rates of water evaporation, thickness of the skin, density of the meat/pulp inside will affect how each kernel dries and shrinks, thus its shape and texture when its a \"dry\" kernel. to be clear there is still water inside, thats why they pop when you heat them.",
"Also there are two different varieties of popcorn from a culinary standpoint: butterfly and mushroom. butterfly is the irregular shaped ones that most people just eat as \"popcorn\". mushroom is the rounded, \"firmer\" variety that is usually used for coating like caramel corn or kettle corn, as it is a sturdier variety and less \"fluffy\"."
]
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[],
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|
3ax6c7 | the splitting of the atom.. what is it and why is it so significant? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/3ax6c7/eli5_the_splitting_of_the_atom_what_is_it_and_why/ | {
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"When an atom splits a releases a HUGE amount of energy. With some atoms like Uranium, when an atom splits it releases energy but also a few particles called neutrons. These neutrons each go on to hit more atoms creating a chain reaction. If there are enough atoms the chain reaction keeps going on until it runs out of fuel or it fly apart from the energy created. This can be taken two ways. You can make a bomb by creating ideal conditions for the splitting. This bomb will be very powerful because split atoms (as stated above) release tons and tons of energy. You can also a chain reaction but put other elements in it that absorb some of the nuetrons. This makes it so it doesn't fly apart and you use that energy as the basis of a nuclear power plant.",
"Imagine you and your brother own some Lego, where each piece is magnetic and can snap together (releasing energy) and some can be forced together (requiring energy). Everyone else you know has this magnetic Lego, and spend their time building weird and wonderful things out of them. They're the smallest piece in the toy set. \n\nOne day your brother gets a very rare Lego piece and looks at it closely... It looks like even smaller Lego pieces are coming off of it, and what's left isn't the piece he started it with. Further more, it looks like each time a piece changes it happens spontaneously and releases an enormous amount of energy for just just single Lego piece. These are no longer the smallest pieces in the toy set! You call up all your friends to show it off.\n\nYears later you find another piece that does the same thing, this time though I gives of a lot of energy! A lot! You put it all together in the desert. You figure that out that if sub-lego pieces hit the unstable pieces then they should break up, releasing more sub-lego pieces... In an ever increasing amount, with the amount of energy released being phenomenal. \n\nBoom, you were right. "
]
} | [] | [] | [
[],
[]
] |
||
334dpv | could a baby get sleep paralysis? | And if it did, what would it see? Because most people see monsters and hear demonic voices but a baby wouldn't know either of those things. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/334dpv/eli5_could_a_baby_get_sleep_paralysis/ | {
"a_id": [
"cqhfa5o"
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"score": [
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"text": [
"A baby could physiologically get sleep paralysis, sure. As to what their subconscious produces (and let's face it, babies are cognitively almost entirely subconscious), no one really knows. Technology has not gotten to a point where we can figure out what's going on in the brain of beings unable to effectively communicate. "
]
} | [] | [] | [
[]
] |
|
5ej1o5 | What happens in the rest frame of a particle that is causing Cherenkov radiation? | I understand that Cherenkov radiation is what happens when a charged particle in a medium exceeds the local speed of light (not c). What does this look like in that particle's rest frame? Are the photons travelling backwards?
| askscience | https://www.reddit.com/r/askscience/comments/5ej1o5/what_happens_in_the_rest_frame_of_a_particle_that/ | {
"a_id": [
"dadpg5w"
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"text": [
"This is interesting to think about for a bit. You are correct, the pulse of light would be moving \"backwards\" from the particle's point of view. But this is different from light moving away from you in most contexts because here the Poynting vector and the group velocity are now in opposite directions. I'm not really sure what all the consequences of that would be, to be honest. You get a similar situation without the Doppler shift when light enters a material with a [negative refractive index](_URL_1_), which you can achieve with some metamaterials.\n\nThis radiation doesn't really look like anything from the particle's point of view because the particle never catches its own shock wave. But as soon as the particle pops out of the dielectric material the Cherenkov radiation would catch up with it, only now as \"normal\" photons. You might also need a mirror or lens to direct the radiation at the particle, since Cherenkov radiation propagates at a fixed angle. The light will also reach the particle in the reverse order it was created, so the particle would see a \"time reversed\" view of the process. \n\nI did find a paper that works this problem out for protons and neutrons [here](_URL_0_), but I can only access the abstract. \n\nAs a side point, it is better to interpret the photons in a dielectric material as quasiparticles that have a finite rest mass and propagate at a speed less than c rather than real photons moving at c and \"bouncing off\" of atoms. The interaction of the electric field with the dipoles of the atoms/molecules in a dielectric isn't analogous to absorption and emission of real photons by atoms."
]
} | [] | [] | [
[
"http://rspa.royalsocietypublishing.org/content/374/1759/531",
"https://en.wikipedia.org/wiki/Negative_refraction"
]
] |
|
35qxkl | how do you pay bills in prison? (for long sentences, multiple years) | Do you still have access to your bank accounts? What about bills that can't be cancelled and must be repaid like student loan payments? What if you have no savings, do you just spiral into debt and collections? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/35qxkl/eli5_how_do_you_pay_bills_in_prison_for_long/ | {
"a_id": [
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"text": [
"Well, first off, you cancel everything you can. Terminate the lease, sell the house, let them repossess the car.\n\nAs for student loans, a prisoner can apply for the income based repayment schedule, and with the zero income, they won't be paying on the loan.\n\nBut yes, there may well be a lot of debt and collections, just one of the many problems that someone has to deal with as a consequence of being unwise enough to commit a felony.",
" > Do you still have access to your bank accounts?\n\nYou do.\n\n > What about bills that can't be cancelled and must be repaid like student loan payments?\n\nYou are encouraged to liquidate all of your assets and put the money into an account to be used to pay any expenses you can't cancel.\n\n > What if you have no savings, do you just spiral into debt and collections?\n\nIf you are in prison long enough for this to be an issue, you probably committed a felony. It is legal to discriminate against felons, which will probably have a far greater impact on your ability to borrow money than bad credit will. Declaring bankruptcy will not make things significantly worse.\n"
]
} | [] | [] | [
[],
[]
] |
|
5kbb1o | why do gas stations list the gas price to the thousands place? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5kbb1o/eli5why_do_gas_stations_list_the_gas_price_to_the/ | {
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"text": [
"Off topic: To the 3 people who commented, you are [shadowbanned](_URL_0_) since it says 4 reactions but i only see 1. Visit /r/ShadowBan/ to see if for Reddit as a whole, if not, then just this sub. "
]
} | [] | [] | [
[
"http://imgur.com/a/5e3wk"
]
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||
ygcab | - totalitarianism and politics | I am supposed to give a speech about totalitarianism and how people's or countries' form of government affect their politics and other. I searched but websites like wikipedia uses big words, politic words that normal people would never use (another way of saying I'm a big dumb). Please ELI5, do go into details about Totalitarianism and explain it like i'm 5. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/ygcab/eli5_totalitarianism_and_politics/ | {
"a_id": [
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"text": [
"Totalitarianism is another way of saying that the country's government (Usually one person) gets to do whatever it wants. That's where the 'total' comes from. The government controls the economy, military, art, education, science, everything. They totally control the public.",
"I dont exactly agree with Schmaltzed. \n\nTotalitarianism is political system, where the government tries to control every aspect of public but ALSO private life.\n\nIn contrast a government that just controls the economy, military, art, education, science is not perse a totalitarian government. \n\nThe greatest example is Soviet Union. It was all about building up a Nation where everyone would have equal rights and chances for a stable future. The State literally built schools, paid for your education, found a job for you, paid your pension. You never really had to worry about your future, state was promising you that stability. While it sounds great to live that , one must realize that in case you were unhappy with how things were, you had no liberty or chances to change it.\n\nA things about Totalitarian Government ( from top of my head):\n1. uses media to justify and promote itself.\n2. limits freedom of speech ( as a back up to 1.)\n3. strives to control every aspect of your life.\n4. not perse a dictatorship\n5. sells ideology, brainwashes citizens.\n6. low on corruption (officials also brainwashed)\n....\nedit: spelling"
]
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[],
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|
2no3ks | women who use contraception, stopping their periods for months/years at a time, where does it go? and is it unhealthy? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2no3ks/eli5_women_who_use_contraception_stopping_their/ | {
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"First, pick your poison. Hormonal contraception, barrier contraception, Intrauterine devices, etc...\n\nLet's assume you're talking about hormonal options which include pills and shots and such.\n\nGenerally speaking, all they do is prevent the woman from ovulation by tricking the body into thinking it's in the follicular phase, which is when follicles mature and it's the last stage before ovulation.\n\nOvulation of course is when a woman releases ovaries and is at the prime time to get pregnant. \n\nThe majority of hormonal contraceptives and conception boosters focus on the ovulatory phase of the menstrual cycle because it is the most important determinant of fertility. Hormone therapy can positively or negatively interfere with ovulation and can give a sense of cycle control to the woman.\n\nSo, the periods just stop. And it's not unhealthy when done properly.",
"Also, many forms of hormonal bc do not stop menstruation, they prevent an egg from dropping/implanting. The uterine wall is still shed monthly.",
"My gynecologist said that it's absolutely 100% fine. There are no adverse side effects to choosing to not menstruate every month. Some IUDs stop your period without hormonal assistance, but what I do is just take birth control pills without stopping for the last week of the month (this is the week that a period is triggered by the absence of birth control hormones). As long as you normally react well to hormonal birth control methods, it should be fine. The only problems I've noticed is that your first period after a long streak of not having any sometimes results in a dark brown or black colored menstrual fluid. This is fine. It's just a build up of old blood. I also noticed that my body is way more receptive when I miss a birth control pill (doesn't happen often, maybe twice a year). When I had been taking it normally, I'd have to miss two or three pills before my period started. Now that I take them constantly, if I miss one pill, even doubling up the dosage the next day won't stop a period from coming. Sometimes it's just a day or two of spotting, but sometimes it's like a full period even though I'm continuing to take the pill each day. But aside from that, I'd highly recommend this method to women who have had luck with hormonal birth control before and aren't particularly attached to their period. It's a great way to 1) avoid the mess/cramps/hassle/week of no sex and 2) save eggs (if you're into that). "
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[],
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480mt0 | why do guns recoil upwards and not any other direction? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/480mt0/eli5_why_do_guns_recoil_upwards_and_not_any_other/ | {
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"You are referencing *muzzle rise*.\n\n > The primary reason for muzzle rise is that for nearly all firearms, the centerline of the barrel is above the center of contact between the shooter and the firearms' grips and stock. The recoil forces from the bullet being fired and the propellant gases exiting the muzzle act directly down the centerline of the barrel.\n\n > **If that line of force is above the center of the contact points, this creates a couple, a rotational force. That couple causes the firearm to rotate, and the muzzle end to rise upwards.**\n\nSource: _URL_0_",
"Because the part that fires the bullet is above the part you hold onto.\nNotice how the handle is always below the barrel. The part the bullet comes out of goes back and its like leaver with the handle as the fulcrum. \nIf the barrel was directly infront of the handle it would push only backwards, but this would make the gun impossible to hold with two hands and too long to fire with one hand. \nIf the barrel was underneath it would be very difficult to aim with. Plus gravity and recoil would combine to make it hard to control.",
"You hold the gun at the bottom and rear of the rifle or handgun. When fired, the force of the burning powder in the gun pushes in all 6 directions, up, down, left, right, forward, backward. Up/down and left/right are equal and balance out. \n\nForward a bullet is forced out, and backward is against your arm. Since you're holding the gun, your arm acts like the pivot point for the gun, causing the front to rise, as the rear of the gun pivots downward.",
"Guns, naturally, recoil in exactly the opposite direction of that of the bullet. Since you're holding it below the line of fire, you're creating a rotation point. The backwards force goes over that point, and introduces a rotation.\n\nIn a similar way, pushing down on a door lever will make it rotate around the axis. "
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2rdy9z | How did the various non-Russian(/Slavic) ethnic minorities of the USSR feel about fighting for them in WW2? | One of the blokes who put the USSR flag on top of the Reichstag was a Georgian. Everywhere else in Europe, nationalist tensions were flying high.
How did the various non-Russian people (eg Kazakhs, Georgians, Armenians) in the formerly Russian Empire, now USSR, feel about fighting for their Russian overlords, who I'm guessing they probably weren't best pleased about being ruled by. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/2rdy9z/how_did_the_various_nonrussianslavic_ethnic/ | {
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"There was an Azerbaijani Soviet \"Opa\"(Grandpa in German), 94, who had coincidentally answered this question 2 times. You could check his answers here:\n\n-2012 _URL_0_\n\n-2014:\n_URL_1_",
"Well Georgians and Armenians held important posts in the USSR military complex and the science community lets not forget the Ashkenazi Jews who played a pivotal role in the creation of the USSR. I would say the USSR was a lot more inclusive than other empires "
]
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"http://www.reddit.com/r/IAmA/comments/xi6ve/iama_92_year_old_azerbaijani_world_war_ii_veteran/",
"http://www.reddit.com/r/IAmA/comments/2dvsb1/iama_94_year_old_wwii_veteran_who_was_conscripted/"
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1aug8b | Somewhat of a meta question: What would Reddit's Historians put at the top of their 'recommended reading' lists for pre- or early-firearms warfare, from a strategic / logistics perspective? | If I look at a history text from any course I've taken in the past (admittedly, the minimum required for the most part), or watch a military documentary or whatever, these two details seem to get glossed over big time. Either you get a way-zoomed-out look, where they just basically list off winners and losers, or a super close-up look at how bloody this battle was or what the life of the average soldier was like or whatever. I can't help but feel that somebody, somewhere along the lines, had to have studied and written down a "Book Of Things Every General Should Understand About War, Past And Present" or something like that, hehe. Surely (most) famous military leaders didn't just get handed command on a whim and luck out at being exceptionally good at it - they had to have studied this stuff, right? So what did they read, and where can I get a copy? I'm looking for everything from overall war strategy to specific battle-level tactics to logistics of supply, transport, etc. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/1aug8b/somewhat_of_a_meta_question_what_would_reddits/ | {
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"Martin van Creveld's *Supplying War* is a good history of operational and tactical logistics. For my dissertation on historic military supply chains I needed to pull information on logistics from a number of sources as there is very rarely ever a logistics review of campaigns prior to the 20^th Century.\n\nWhat I was able to establish, for the English longbow in particular, was that there is an overlap between modern supply chain management and the practices used in medieval times. This is probably by accident, the Feudal system of government was successful because it provided an ordered supply chain for the monarch. It also relied on market forces and trade guilds to ensure that high-quality products were produced consistently. I was unable to find any evidence that Henry V had been given any specific instruction in supply chain management!\n\nHe would, however have been intructed in martial matters from a young age, and part of this would have been how to move large numbers of men and sustain an army in the field. Many medieval commanders in Western Europe would have read Vegetius' *Epitoma Rei Militaris*, which provided some advice on logstics and tactics which remained relevant until the late medieval period. Other writers, such as Christine de Pizan, also produced works which influenced commanders' behaviour, but more typically concerning their role within the concept of chivalry.\n\nPractical experience played a large part. For the English every opportunity was taken to expose future commanders to campaigns: Henry V commanded the English army to suppress the Welsh uprising of Owain Glyndwr when he was in his early twenties; Edward of Woodstock (The Black Prince) fought at Crecy with his father Edward III and found himself involved in the melee at one point, his father refused to send him help on the grounds that \"the boy\" needed to \"earn his spurs\"; Edward II fought on campaign in Scotland with Edward I, and his poor prowess in martial matters did little to endear him to his future subjects.\n\nThe Order of the Garter, established by Edward III, also provided an oppirtunity for England's senior commanders to share opinions, provide advice and guidance, and discuss military matters. These men formed the core of the command structure of the mid to late medieval English army and an English king would never be short of highly capable tactical commanders or volunteers for \"death or glory\" missions!\n\nCertainly there is plenty of evidence that Henry V studied the campaigns of his forebears, especially those in France, and so understood intimately the optimal structure for the English army and how best to employ it. He couldn't have learned this from Vegetius or any continental writers because the role of the longbowman meant that the English army was formed unlike any other in Western Europe."
]
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[]
] |
|
3it0ve | Can you all help me come up with some interview questions to ask my grandfather, who live through the Japanese occupation of Indonesia during ww2? | My grandfather (opa) is Dutch-Indonesian. I'm a writer and I'm planning a trip to visit and interview him about his experiences in general over the course of his life, but I'm hoping to get him to talk about the Japanese occupation of Indonesia, which he lived through and doesn't like to discuss. Can you guys help me think of some tactful questions to ask him? Thank you. | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3it0ve/can_you_all_help_me_come_up_with_some_interview/ | {
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"First of all, apologies if any or all of the below is completely redundant. I don't know your experiences conducting interviews like this so I am assuming no to little familiarity with the process. Feel free to ignore this post if everything I am saying is redundant. \n\nYou might get some good answers posting in /askanthropology also. Conducting these sorts of interviews has often been the domain of anthropologists collecting \"oral histories\" (as opposed to \"written histories\"). \n\nGenerally though, these sorts of interviews are less structured and more influenced by what your informant (your grandfather in this case) are willing to talk about and what they think would be important. You can ask more directed questions, but what you think (or what /askhistorians thinks) is important may not be the same as what your grandfather thinks is important about his experiences. Sometimes, the most exciting information doesn't come from your line of inquiry but what your informant might think is most valuable. \n\nI'm sure someone else with actual expertise in WW2 can help you with some more specific historical questions, but I just wanted to chime in with the more anthropological viewpoint. Go in with some questions of interest to help guide the discussion but be open for the interview to go places you don't anticipate. This is especially true when interviewing those who suffer from trauma - they may be reluctant to speak about their experiences so you may have to go slow at first by allowing them to only speak about what they are comfortable with. \n\nAll that said, being familiar with the outline of history in Indonesia in WW2 is really crucial to understand the context of your grandfather's experiences. \n\nHere are a few resources that might be helpful:\n\n[Principles and Best Practices](_URL_1_) from the Oral History Association\n\n[Handbook on Oral History](_URL_0_) from Baylor University Institute of Oral History\n",
"Do you speak Dutch? There's a great deal of literature in Dutch from camp survivors who later became novelists, and as a writer you might find that as helpful as any formal, non-fiction history books about the period (which I am anyway not qualified to recommend). Wellknown writers in Dutch literature who wrote books dealing with this are Adriaan van Dis, Jeroen Brouwers, Rudy Kousbroek and Hella Haasse.\n\nSome books that might be most relevant:\nHella Haasse's *Oeroeg* has been translated into English (sometimes titled *The Black Lake* ) but does not deal with the camps directly. It is however an excellent read.\nClara Olink Kelly's *The Flamboya Tree: Memories of a Family's War Time Courage* is a memoir about life in the Tjideng prison camp.\nJeroen Brouwers' *Sunken Red* is a novel/memoir about life in the Tjideng camp and its repercusssions on the authors later life, though the writer has been accused of exaggerating the horrors somewhat.\n\nHope that helps!"
]
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"http://www.oralhistory.org/about/principles-and-practices/"
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18gh8i | How are heterochromias formed? Are they just a mistake or carried through your DNA? | I have several sectoral heterochromia and I'm curious about how they form. Is it a marker in my genes that causes this or simply a mutation or mistake when my eye was being formed? Is it something I could pass on to my children? Thanks!
[My eyes as example] (_URL_0_) | askscience | http://www.reddit.com/r/askscience/comments/18gh8i/how_are_heterochromias_formed_are_they_just_a/ | {
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"There are cases indicating that sectoral heterochromia like yours was transmitted from a parent to child, which suggests that it's germ-line genetic, and not simply mistakes that arise during iris formation. Melanocytes in the iris are of neural crest origin, so it might suggest that you have something wonky going on with your neural crest cells. Not bad per se, but unusual. Do you have any other unusual features? Uneven pigmentation on the rest of your skin when you tan or white patches in your hair? You're very pale so the uneven skin pigmentation might not be noticeable. Deafness? You would typically have these features from birth, so don't worry that you're suddenly going to develop them. There are several genetic disorders affecting neural crest that can cause this kind of heterochromia, like Hirschprung's disease and Waardenburg Syndrome. The genetics of these syndromes aren't straightforward in all cases, they can be multifactorial, so it's hard to say what the likelihood of transmission is. It's likely to be genetic, but could be either dominant or recessive (or just plain complicated).",
"Heterochromia is primarily a difference in melanin between two eyes or two segments of the same time - there are several different mechanisms that I can think of offhand for how they could be formed. However, I wasn't able to find a definitive answer in a quick browse on the 'net.\n\nGenetically, you can have mutations that arise during fetal development, which would cause the regulation of the melanin created to differ in the two eyes. Because the brown is the colour when there is melanin, and the blue when there isn't,having two different colour eyes is simply a function of changing the amount of melanin in the iris.\n\nAlternatively, it's possible to have a mutation occur during development of the eye itself - one cell splits off, has a small mutation, and tada, you get a sectoral heterochromia. This is because we all start off as one cell, and keep dividing over and over to create the billions of cells we need to be a functioning human. if one cell has a mutation, all of the daughter cells that it in turn creates will carry that mutation. \n\nOf course, there are also genetic causes for it - which I presume are related to sex-related chromosome inactivation. All women have to inactivate one copy of the X chromosome (as they carry two of them in each cell, men only carry one in each cell, so it doesn't affect men.) In some cases, the the X chromosome inactivated is inconsistent between neighboring patches of cells, which leads to mosaicism. If there's pigmentation instructions coming from the X chromosome (or something that causes pigmentation instructions to differ depending on the chromosome) you get some interesting results (differing colours of skin in patches - or heterochromia).\n\nAnyhow, the last part of your question is if you could pass it on to your kids. While I understand that there are forms of heterochromia that can be inherited, if the origin of the mutation happened in a cell in the eye (sectoral heterodhromia), then the answer is no, because the mutation that caused the pigmentation change happened in a cell that was not a predecessor of your reproductive cells.\n\nYou can visualize the heritage of the cells in your body as a tree, with a single root (the original fertilized egg.) Only those cells that were directly in the branches leading to your ovaries (or sperm for men) have the chance to pass on heritable changes. The cells in the branches of the tree that led to the eye may meet somewhere at the root of the tree, but the mutation happened long after the branching point.\n\nThat's also why Lamarkian evolution didn't have a chance. (Chopping off your arm won't cause your children to be born without an arm.)\n\n\n\n\n\n"
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2eksnw | So many units! - What are the differences between a gray, RAD, and roentgen, and do how do they take into account differing radiation types? | And is there any simple way of comparing radiation from nuclear power to say, radiation from being outside my boron doped box? Edit: I meant to say, and/or Rad, Gray, Sievert, Rem... | askscience | http://www.reddit.com/r/askscience/comments/2eksnw/so_many_units_what_are_the_differences_between_a/ | {
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"Rad and Gy don't take into account radiation types. They only measure energy per unit of mass where it is deposited. 1 Gy = 1 J/kg, and 1 rad = 1 cGy.\n\nSv is used to measure [dose-equivalent](_URL_0_) and it depends on the radiation type using quality factors. The dose in Gy of each radiation type is multiplied by the appropriate factor and everything is added up, so for instance if a target receives 1 Gy of X rays and 1 Gy of alpha particles, then the dose equivalent is 21 Sv because the quality factor is 1 for X rays and 20 for alpha radiation. Roentgen equivalent man (rem) is also used for dose-equivalent, 1 rem = 1 cSv.\n\nThis is a somewhat subjective unit and much of it is based on empirical research. As new evidence becomes available the weighting factors are updated by the recommendations of the [ICRP](_URL_1_).\n\nDose-equivalent is not to be confused with [effective dose](_URL_2_), which depends not only on the radiation type but also on which organ has absorbed it. The trick here is that they are measured in the same units (Sv and rem) :-/\n\nSo, to answer your question about comparing nuclear power to boron, no, it's not simple because a nuclear reactor may produce a combination of different radiation types (neutrons, gamma rays, etc). If you know exactly how much radiation of each type is produced then it only takes a simple calculation, but radiation shielding is also different for each type so it's hard to predict what you'll be receiving on the other side. Usually software simulations are used to get an estimate.\n"
]
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"http://en.wikipedia.org/wiki/Effective_dose_\\(radiation\\)"
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5fmetr | why you have to pay the bbc for your tv licence to watch programmes on itv, ch4 etc. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5fmetr/eli5_why_you_have_to_pay_the_bbc_for_your_tv/ | {
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"Because they are all part of the same funding pool. The obviously don't know what station you are watching at any given time, so there is no way to make that distinction, or somehow split profits based on what percentage you watch one over the other. \n \n > Are there any other situations that occur where you have to pay a rival company...to use another company's services? \n \nThat's not what's happening, you are paying the government for the privilege to watch any live broadcasted tv program OTA/cable/satellite/online (anything except on-demand content basically), and that money is collected and used to help fund the BCC/ITV. Trust me, if you didn't have to pay the license, your taxes would just increase to compensate."
]
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||
rw5xe | I just finished watching the documentary series, 'The Story of India' by Michael Wood, and would appreciate if any of you'll could recommend books to learn about Indian history? | Firstly, the documentary series was an excellent viewing pleasure and credit to Wood in the way he presented it. In[ this](_URL_0_) interview about the series he states,
> Question: Was it hard to select six hours from 10,000 years of material?
>
> Response: It was a nightmare. To do justice to Indian history, you need 100 hours — 10 would’ve been the minimum required.
----
As an Indian, I'm ashamed to have a very basic knowledge about my culture's history. Although I did study Indian history during school, my memory is very sketchy and have little to no recollection of it.
Thus, I wanted to know if experts in this field could recommend any good books that provide an objective view and summarises India's vast history. | AskHistorians | http://www.reddit.com/r/AskHistorians/comments/rw5xe/i_just_finished_watching_the_documentary_series/ | {
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"I'm the opposite of Michael Wood, where I'm hyper focused on a single period of India and only know a limited amount about the rest. The period I'm interested in is the Mauryan Empire, and if you think of it as being an Indian state then the Kushan Empire as well. I'm particularly focused on the Indo-Greek community during this period (roughly 300BC-100AD). Unfortunately this subject has been poorly explored until relatively recently, and the biggest problem is finding a book that actually gives you something resembling an overview of the subject. But I have got one book that I would recommend as an introduction to this particular aspect of Indian history, which is *India and the Hellenistic World*, by Klaus Karttunen. This is very much an academic look at the subject, and may be difficult to find. But if you can then it's as close as anyone's come to summarising the relationships between India and ancient Greece. There is the caveat that this was published in 1997, we've had another 15 years of work on the subject since then and so not everything in it may be up to date.",
"*The Discovery of India* by Jawaharlal Nehru. Part memoir, part history, part autobiography by one of the chief architects of modern India."
]
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d4bbr1 | British empire during WW1 | What countries that were ruled by Britain participated in ww1 and what was their job? I know Canada was in the war and they sent soldiers to vimy and other places. What was India’s impact and what other countries under their rule joined and were they forced to join? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/d4bbr1/british_empire_during_ww1/ | {
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"Just about every country within the British Empire contributed to the British war effort in one way or another. Like Canada, the self-governing dominions of New Zealand, Australia and South Africa sent troops to fight on the various fronts. Their participation in the war was never in question as a British declaration of war automatically meant the dominions were also at war. The level of the dominion commitment however was entirely up to each dominion. Canada and Australia both contributed five infantry divisions as well as several mounted brigades whilst New Zealand contributed a single infantry division and a mounted regiment. South Africa contributed a number of military units, most served on the African continent against German colonial forces in what is now Tanzania and did much of the fighting against the famous Lettow-Vorbeck. One unit served on the Western Front and others in the Middle East during the Palestine campaigns.\n\nIndia, where self government had not been attained, a declaration of war was made by Viceroy Charles Hardinge. Though he did this without consulting the fledgling Indian government, the declaration of war was largely embraced by the Indian population and enormous numbers of volunteers came forward to fight for Britain. The Indian contribution was the largest of the colonial/dominion/imperial contingents with more the a million Indian soldiers serving overseas in all theaters of conflict from Gallipoli to France to the Middle East."
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73gdn3 | Does ice melt more quickly when mixed with alcohol? | Imagine I had ice and Vodka at the same temperature, -10C for example. I set the ice out at room temperature to melt. Would the ice melt any faster if I poured the vodka over it? | askscience | https://www.reddit.com/r/askscience/comments/73gdn3/does_ice_melt_more_quickly_when_mixed_with_alcohol/ | {
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"Yes it will, especially if the glass is not chilled. The heat will conduct through the liquid and into the glass much faster than the gas (air) surrounding just the ice. There is also a greater surface area of the cold system after the liquid pours over it and heat transfer is proportional to boundary area. Finally, water vapour can absorb into the concentrated alcohol and this will raise the temperature somewhat over time as well (as it is like the opposite of evaporation of a hot liquid which effectively cools it). This will be more effective over the boundary surfaces of the liquid-glass-ice system (i.e. liquid surface and glass surface) compared to the air-glass-ice system, where condensation will occur on the ice, and other heat transfer would be pretty limited"
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5zr6ak | What really happened in Ireland to be so poor ? | What happened in ireland in the 18-19-20th century that makes Ireland one of the poorest country ?
Am curious .
Thanks
Edit 1: Thanks for all comments | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/5zr6ak/what_really_happened_in_ireland_to_be_so_poor/ | {
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"While not the only cause, one of the largest contributing factors was The Great Famine, or The Irish Potatoe Famine that started in 1845. While the potatoe blight had happened all across europe, Ireland was affected much greater than any other European country, due to Corn Laws that the English passed, causing a great majority of the Irish peasents to be dependent on the Potatoe as their staple crop. It's estimated that Ireland lost upwards of 20-25% of it's population during the Famine to starvation and emigration, most of which were the working class, who usually keep a fuctioning Industrial economy going, and help it boom.\n\nThere's many many other factors, mostly cultural and the British's impact on the isles, but the Potatoe Famine is one of the easiest to see and talk about.\n\nMy source details the Irish economy extinsively iin the early and mid 19th Century and the impact the famine had on it. It's a bit dense, but a great read if you're REALLY interested in the time period for Ireland.\n\nSource: Mokyr, Joel. 2013. Why Ireland Starved: A Quantitative and Analytical History of the Irish Economy, 1800–1850."
]
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emg093 | Why haven’t black boxes in airplanes been engineered to have real-time streaming to a remote location yet? | Why are black boxes still confined to one location (the airplane)? Surely there had to have been hundreds of researchers thrown at this since 9/11, right? | askscience | https://www.reddit.com/r/askscience/comments/emg093/why_havent_black_boxes_in_airplanes_been/ | {
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"text": [
"In some cases, data is already streamed live. For example, some aircraft engines stream data to the engine manufacturer during flight, so the manufacturer sometimes knows about potential problems before the flight crew do.",
"One of the possibilities when considering designing something like a real-time streaming solution would be that doing so would require additional hardware that would likely need to mounted externally (i.e.: antennae for transmitting or receiving signals). As soon as you damage _that_ subsystem, your streaming solution stops working.\n\nAs such, you can't rely on a streaming solution to always work, in which case you'd still need a blackbox recorder as a backup anyway.",
"It would cost a lost of money.\n\nWhy would airlines (an industry always struggling to keep profit margins up) spend money on something that is not government mandated, and has no potential to increase revenue.\n\n & #x200B;\n\nSecondly to whom would you send the data? I imagine you ask this question in relation to the Iranian government not giving up the black box data, but would this help? Does the data go to the manufacturer? The government of the manufacturer? The airline, their government? The country of origin, of destination? Would require a good deal of international cooperation to get this fully fleshed out.",
"1. Airplanes crash extremely rarely and more so crash so badly that the aircraft is completely destroyed even more rare.\n\n2. The amount of data stored in flight data recorders is very high. There's hundreds of sensors all saving data at a pretty high rate. The fastest way to transport a hard drive full of data is still mailing the hard drive, rather than passing that over even high speed internet.\n\n3. Aircraft still have huge lengths of time where they're completely out of voice communications when over the ocean, let alone streaming high bandwidth data.\n\n4. There's thousands and thousands of aircraft in the air at any point in time. That's a lot of data to store if it's streamed.",
"it is more stuff that can break, think about your hammer, you dont have a screwdriver in it or have it as a ham radio, simpler systems don't break as easy, the same reason that survalence video is in low quality.",
"Because manufacturers aim to make money and comply with government regulations and no more. If it isn't a feature that contributes to the bottom line, they won't include it. You can't blame a business for wanting to make money.",
"Well... the short answer is: that's not really their job. Essentially, planes are always kind of doing that anyway. They are, in various ways, in regular communication with the rest of the system. They've already got ways of communicating everything that they should need to communicate with everyone that they should need to communicate it with as they need to do so.\n\nBut unexpected things happen. And when they do happen, after the fact, once the emergency bit has been taken care of, the question becomes 'what exactly happened' so that we can figure out if something that should have stopped this from happening failed to do its job, or if there was something we didn't even know to worry about that we should pay more attention to in the future. That's the job of the black box, to let us figure out what happened after the fact.\n\nIf we did hook up the black box so that it was constantly communicating everything it knew in real time, that wouldn't actually be terribly useful. Most flights go as expected. Massive amounts of information would have to be communicated over great distances and 999 times out of 1000, actually even more often than that, that information wouldn't ever need to be glanced at, because the parts of it that needed to be know are already known by the people who need to know, the pilots.\n\nSo, what about that one in a thousand, or more accurately, one in a million situation, could that information be used to save lives? Probably not. Because it isn't enough to have the information, we have to know what it means. The people who analyze the black box information are trained to do that. They're also doing it with access to other information, like what exactly happened, so they're comparing what they know from the wreckage and eye witness accounts, etc, to what the black box is telling them.\n\nIn order for there to be any point to having a black box in constant communication, we'd need someone to be able to analyze the information as it's coming in.\n\nThe day may come when we have AIs who can take in all of that information, analyze it in real time, and spot problems before they become disasters, and when that day comes, hopefully we'll be in a position to set up black boxes in the way you described, but for right now, the amount of data the black box records is mostly useful in looking back to figure out what happened.",
"Something like this probably will happen eventually once these internet beaming constellations like Starlink are online and affordable. Right now, the bandwidth and equipment is much too expensive for the very few times it might have been useful. 100,000 flights happen every day globally and only a handful of accidents over the last few decades where this capability would have made a difference",
"I work with aircraft telemetry. On a test aircraft, we telemeter only a small portion of the parameters we record, because there isn't enough bandwidth to send everything in real time. It's probably not feasible to live stream all the parameters a black box records, and its easier to just make them really hard to destroy and recover the data later.",
"A black box is two data recorders, one that's recording real-time information about plane and one that's recording voice. \n\nThe information is useful after a crash, or after a near miss/emergency, but it's not particularly useful any other time. \n\nIt's hard to estimate how many planes fly a day, but based on FAA information on [_URL_0_](https://_URL_0_), just the US FAA handles: 16,100,000 flights a year (including international flights that enter FAA areas). That's 44,000+ daily flights. There are 5000 planes in the sky at any time at peak travel just in the US alone. \n\nIn 2019 there were 14 fatal crashes *globally.* \n\nThe amount of real-time data streaming you'd need to track even just the domestic commercial flights, plus cargo flights would be staggering. Streaming telemetry and voice from the entirety of a flight's transit would require massive amounts of data, storage and processing. And it's only needed those 14 times a year. \n\nThere are limited ways to transmit data from a plane, you've got terrestrial and satellite. Terrestrial wouldn't work, there are too many hops between towers. Satellite would be available, but someone would have to put the satellites up just to record flight data. If you've ever seen how crappy in-flight WiFi is, imagine how bad having to move the data from 16 million flights would be. \n\nYou couldn't rely on that transmission either, because it's another system to go down, satellites lose communication etc. \n\nThe flight data recorders and cockpit voice recoders are designed to survive 3400Gs and temperatures exceeding 1000º C (1830º F). \n\nThe NTSB has proposed cockpit image recorders as well, because control panels are now electronic—when a plane crashed with an analog gauge it usually stayed on the last position at impact. LCD screens just break. \n\n\n(A good overview is here [_URL_3_](_URL_2_))\n\nIn 2014 after the Malaysia flight vanished, there were pushes to make planes transmit their data or to eject from planes before crashes. \n\nHouse Rep David Price called for black boxes that would eject after Malaysia Flight 370 vanished. \n\n\"But he said the 9/11 Commission recommended after the terrorist hijackings in 2001 that planes carry ejectable \"black boxes\" to make them easier to find. Navy planes have carried them for years, and Transportation Security Administration was given $3.5 million in 2008 to study and test the proposal.\"\n\nWhich is good except, it's not moving along very well. The same article from that quote points out that F/A 18 Navy jets have black boxes that eject on impact detection, or when the ejection seat is triggered, and they float at well. \n\nIn many cases, you don't need a FDR and CVR to figure out what happened, though of course they're always helpful as they show you exactly how the crew and the plane reacted. In the 14 2019 incidents, one was an attempted hijacking . There was no crash, the hijacker was killed, so that's considered a flight-based fatality for some reason. Three were planes that overshot the runways. The reason for those crashes is almost always pilot error. \n\nThere was one bird strike (cause of crash, birds), one was a collision between two planes (cause of crash, collision), one plane hit the runway twice, banked, and hit a building. Passengers who evacuated via the wing-exits slipped on ice on the wing. (cause of crash, ice). One had a plane flying through thunderstorms.\n\nIn a few of them the cause of the crash was determined via FDR or CVR, and several were crew error. \n\nSo to answer your question, there haven't been a lot of researchers thrown at this because it's a problem that would cost an astronomical amount to implement and would only matter in those cases where the black boxes were not retrievable anyhow.",
"Seems like a no-brainer, but that's a LOT of data... per plane... per second of flight. It all has to go somewhere and be stored (for how long?).\n\nADS-B broadcasts are one thing, but a full stream of every black box would require a lot of back haul infrastructure.",
" Innovation is a dirty word because the overall safety record in airline transport is so fantastic. If it is not broken, don't fix it. \n\nAircraft the world over still use garbled AM radio over a shared frequency that distracts pilots a hundred miles away. ADS-B is a big step forward, but it is not a great technical solution. For one thing it is not encrypted or authenticated, so it is easily spoofed by a malicious player.",
"High cost, little to no benefit. You'll always have to have a blackbox anyway, because your hypothetical streaming infrastructure (or the link to the same) can go down. So it'll only really help in cases where the blackbox isn't recovered, and that's exceedingly rare.\n\nAnd don't underestimate the cost either, we are talking about a system that has 100% global coverage, high bandwidth (there are up to 20,000 planes in the air at any given moment). high reliability, high storage capacity etc.\n\nNot to mention administrative headaches, like who gets to control the databases etc.",
"Last I saw it had more to do with satellite bandwidth than anything else. The planes when built now mhave options for monitoring in real time the airlines can add. (China is buyjng lots of the monitoring systems).\n\nTheres a company in canada called flyte Aerospace (if I remember correctly) that has been doing this for years and the bottleneck is small pipes on satellites, which were made many years ago and cant just be swapped out.\n\nInteresting is that the planes with the flyt sustem has many thousands of data points it measures continuously about the plane and the black box part is a tiny component. \n\nThe system really is designed to improve fleet efficiency, fuel economy, and it knows before humans when airplane parts are wearing down so interesting things like engine parts can be pre-orderd and shipped to a future stop the plan might be making before anyone in the plan or in maintenance on the ground actually knows a part is wearing out.",
"Mostly it's a situation of cost vs benefit. There are a LOT of airplanes in the sky at any moment. Black boxes are storing several minutes of audio, system logs, the settings on every control, etc... And it only stores a few minutes, writing in a constant loop so the memory requirements are limited. If we were streaming all of that data, that is a LOT of data. Think Twitter levels of streaming data ingestion. Or more.\n\nAll that data would need to be streamed over satellite uplinks, taking a lot of capacity from other, more profitable uses of that infrastructure. Most of the data would then be thrown away as we need that data only very rarely. And when we need it, we don't need all of it, just the last minutes. And the number of times we can't recover the data is even more rare.\n\nSo we would be going to a huge effort to recover data that is nearly always available anyways. So the actual benefit is tiny to the point of being non-existent.\n\nThen realize that in the times we most need it are the times the data uplink is most likely to fail. So under practical circumstances, we would be less likely to get the data we want, or still need to recover the physical storage device anyways.\n\nSo gains are functionally nil (or negative) while costs are tremendous.",
"A lot do. On our aircraft (fairly large advanced helicopters), all system and navigation information is transmitted every 2 minutes. The information is protected, and not even management can access it, but certain individuals can access it under specific circumstances.",
"Perhaps they should be able to be remotely triggered to send data back. This gets around the issue of every plane sending all it's data at once, and reduces the signal to heartbeats. It still allows the data to be retrieved before the black box has physically been collected.\n \nOn the negative side, it would require the black box to have a transmitter and battery backup capable of sending the data after the rest of the plane has stopped working.",
"As I answered elsewhere, this technology exists and is being adopted:\n\n_URL_0_\n\n_URL_1_",
"Would you be able to give me a brief summary of why the bandwidth is an issue? I imagine almost all the data a black box receives is quite simple (a number as a temperature reading once a second, for example), which, compared to most modern data transfer, takes a minuscule amount of bandwidth to transfer. Is the issue that the bandwidth is so limited that even these tiny transfers are an issue, or is it the case that (some of) the data streams are so large even modern bandwidth is too narrow?",
"Qantas have extensive real time monitoring data streams and have a huge amount of machine learning and other things running over the top of the data consistently looking for defects etc. they also download all the data after each flight and ingest it into a data lake which is enormous. \n\nSource : worked for qantas.",
"Because we don't have effective LEO Internet constellations yet which would permit streaming all recorded parameters.\n\nThey \\*do\\* stream GPS coordinates... if you design them to, and pay the subscription fee. The benefit of this is that searchers have an easier time, and the cost is all on the airline - so unless required by law, it's not really economical to pay this extra money for no benefit.",
"There is no technical limitation to what you suggest. It is just overkill. For the 99.999 (how many 9's?) % of flight that take off and land safely, such an exorbitant use of bandwidth is simply waste. Also, oceans cover a big part of the world - I don't know if you appreciate how MUCH area this means. Using satellite transmissions is just expensive.\n\nSo there won't be too much incentive or need for what you suggest to happen. It isn't as though this system PREVENTS crashes so ultimately all this cost is just diagnostic.",
"Frequent flight status transmissions are possible and are being increasingly adopted. The system uses radio downlink where available, and satellites such as INMARSAT in remote areas. \n\nThe protocol is called [ACARS](_URL_0_)",
"This is something I might be able to contribute to. I was previously a director in the aerospace communications industry and one of my roles was to manage a team that sold connectivity to airlines and aircraft operators. I did this all over the world, including Asia and I regularly wrote articles, gave presentations and spoke on panels as it relates to connectivity and aircraft tracking. \n\nThe short answer is that it’s down to technology and cost. Forgive me if some of this is repetitive, as I've not read through all of the comments.\n\nThere’s a technology called ACARS (Aircraft Communications Addressing and Reporting System) that's been around since the 1970s and it sends information via Very High Frequency (VHF) radio as a data transmission. Think of an old school text message for airplanes. Some messages are automated like engine reports and departure messages where the aircraft sends a signal that it has taken off and landed. There are also some manual messages that the pilots can send from the cockpit. VHF is limited by line-of-sight, and a typical VHF ground station can only cover a certain distance, much like a cell phone tower. This is generally around 200 nautical miles at 20,000 feet altitude. VHF stations aren't that big, about the size of a vending machine but they're expensive to deploy and it's a complicated process to obtain and maintain government permissions to legally operate in any country. So while there are VHF ground stations that transmit this data all over the world, it’s still not worldwide because there’s not always a business case for it. Africa is a perfect example where coverage is still sparse. Additionally, due to the range issue, flights over open water do not generally have VHF coverage once you're far enough away from a ground station. \n\nAnother supplementary technology exists called High Frequency (HF) radio. The major benefit of HF is that it's much longer range than VHF. While the stations are generally much larger than their VHF counterparts, there are far fewer of them given their capabilities. HF is usually a cheaper option that satellite and many aircraft use HF when they fly across the pond. \n\nBoth VHF and HF are used for voice and data transmissions every day in the commercial airlines and they are considered very standard means of direct and indirect communication with the ground. The issue is one firstly of cost. The major providers of VHF and HF connectivity for aircraft around the world generally charge based on volume. The more data sent and received, the more it costs. Although there are some specially crafted plans in place and the costs of data transmissions have gotten cheaper, much of the technology on-board aircraft was designed to minimize the amount of data that's sent or received from an aircraft. Secondly, they don't have anywhere near the bandwidth capability to support the high volume data transmissions that would be required for these types of transmissions. These mediums can and do, however, facilitate the transmission of simpler text based messages pertaining to engine conditions, position reports, and manually entered crew messages amongst many others. \n\nNow come satellite communications or SATCOM. SATCOM has been around for decades and is really nothing new. The largest users are the maritime and aviation industries. The major and likely obvious benefit of SATCOM is that satellites are orbiting the Earth and as such aren't limited by terrain. Thus, they can work well if an aircraft is operating far out to sea where terrestrial based ground stations cannot reach. Generally speaking, SATCOM has been wired into aircraft to act as the backup for your VHF and HF connections. Think of this like VHF and HF are your home based WiFi network, but once you leave the house, SATCOM takes over. The first few satellite systems launched were quite limited in their bandwidth and further, they were horrendously expensive to use. If I remember correctly, a call from an aircraft satellite phone (SAT phone) could reach as much as $20 per minute. It's far cheaper now, but still a significant cost over a fleet of aircraft. It costs a lot of money to build, launch and maintain a satellite network so naturally, it was going to be expensive. Airlines operate on thin margins and are notorious for keeping costs to a minimum, thus SATCOM much in the same way as VHF and HF are concerned, was to be used very sparingly and only for specific purposes, if the aircraft is equipped at all. The pilots and aircraft dispatchers that I worked with during my career are still very much in the habit of keeping messages and aircraft phone calls as short as possible due to the legacy of lengthy messages being more costly.\n\nSATCOM is also capable of sending both data and voice transmissions and relatively recently, high throughput transmissions to provide internet connectivity. Today, SATCOM on an aircraft is becoming far more common and much cheaper. Fly a commercial airline today and you're quite likely to have WiFi service available to you, some free of charge and some with a cost to the consumer, the passenger. As the demand grows for connectivity, more companies are looking to increase network capacity and increase available bandwidth and so more advanced satellites are being launched to take advantage of this growing market. Two important points to note here are the bandwidth and cost of this service. I would argue today that the bandwidth is capable of supporting a constant stream of data transmissions from the aircraft relevant to the FDR and CVR, but this is only very recently that this is so. Further, the systems were not all designed to constantly transmit data on an open connection which would be a requirement to provide the \"streaming\" that you're referring to. \n\nThe last point here is the cost. Satellite services are still very expensive to all aircraft operators. Although the costs are lowering, it's still very expensive to firstly equip the aircraft with the appropriate avionics (computer and instrumentation for your aircraft) and to pay for that data connection. A large aircraft fleet such as Emirates, can afford lower pricing based on volume. A business jet operator that operates only one aircraft, however, is not so lucky and they can pay prices that are nearly $8 (USD) per Megabyte (MB) if volume based or between $6 - $25 per minute for a streaming service. It was not unusual for a customer to see invoices in the thousands of dollars for a single month for a single aircraft for satellite data services alone. Even Emirates will likely pay cents per MB which spread across their entire fleet is no small sum of money. In summation, it's still a very expensive service. \n\nSo, those are the general means of communication. I did see some comments related to ADS-B and while that's related and a super cool topic, particularly space-based ADS-B and the partnerships between Irdium, Aireon and FlightAware, ADS-B still does not generally provide the type and volume of data that that's stored within the Cockpit Voice Recorder (CVR) and the Flight Data Recorder (FDR). These two separate \"boxes\" record very specific parameters on-board the aircraft which aid in a determination of the causation of an accident. So while ADS-B information would certainly be helpful in determining the possible location of a lost aircraft and even assist in any possible accident investigation, the picture is not complete without the entire data set that's stored within these two instruments. \n\nWhy is this now a question that comes up all of the time and where do we go from here? Well, although aircraft have been disappearing since the beginning of air travel, the technology today is so advanced that of course we couldn't lose an aircraft, right? Air France Flight 447 and Malaysian Airlines Flight 370 are two very big catalysts for a shift in paradigm and these two incidents have drawn attention to the limitations to aircraft tracking and communications. In my role in the aviation industry, I saw this as likely to change. As more and more data is automatically pulled from the aircraft, bandwidth increases and the cost decreases, I think it will be likely to see raw flight parameter data being transmitted to the ground and further, I expect that civil aviation authorities will be more inclined to mandate the use of a Quick Access Recorder (QAR) and or other technologies which require the date to be routinely stored and transmitted. \n\nLet me know if you'd like further info or any any sources. \n\nTL:DR: Sending data from an aircraft is still quite complex and very expensive.",
"Because rolls royce engines have a good tracker and are constantly updating in real time every measurable variable during operation. This is all live streamed to rolls royce HQ where there is someone monitoring them all the time. \n\nI think the real question isnt that enough to track and monitor commercial airlines",
"In computer engineering, there is actually not physically possible to do anything in \"real-time\", as you call it. There will always be delays due to hardware limitations, the algorithms processing and handling the data and of course bandwidth (aka signal processing). In other words, several layers of technology are communicating and dependent on the layer \"below\". \nAlso, as someone here pointed out, there is a huge amount of data collected (telemetry and parameters, voice recordings etc.) , and it would be impossible to stream it all in \"real-time\". So instead, they prioritize important information the air traffic control needs in order to coordinate the air space. They send this data on low frequencies which results in a low bandwidth, but has a huge transmittion range. Otherwise we would need radar stations everywhere... And even this minimum information is delayed, so I believe the algorithms at the air traffic control are using interpolation and extrapolation to calculate and predict future data based on earlier data, and then corrects itself if needed when the real data comes in from the plane. But I haven't personally looked at these protocols, so I can't say for sure, but it's a fairly common concept in, for instance multiplayer games over the internet.\n\nSo yeah, that's why we can't just stream to a remote area. It would require a fairly complex system in order to work. And money is a huge factor when it comes to this. Some questions have to be asked and answered. So one would have to do a cost-benefit analysis (CBA). First of all, is the investment worth it? What's the benefits of such a system? Does the current black box system work? And so on...\nObviously, we don't find it worth our time and money to improve it, because the current system works. As long as we find the box...",
"When I did my engineer capstone project in school I helped a team develop an emergency deployable glider that contained a secondary black box recorder. The glider would capture images of the plane as it deployed and safely navigated to the ground away from the crash site. It would also relay information about the location of the plane. It’s a bit different than just transmitting raw data but I thought it was a good idea. I believe at the time Boeing was developing a similar technology though.",
"Because of the cost. I'm currently working on a few digital products for one of the bigger aviation companies and I couldn't believe how much would they rather keep the money than improving the experience for the crew and passengers. The stories they've told me in user interviews were downright scary and makes you wonder how there aren't more accidents.",
"I’ve work extremely close with the black box manufacturers, FAA, and air frame manufacturers. And the best and most true answer is Money, It is extremely expensive to develop and maintain such a system. So the easiest solution, keep status quo until the laws force you too.",
"Along with the amount of data and satellite bandwidth/coverage issues, consider that a black box would have much more recent data. According to wikipedia, ADS-B sends updated data every second, and it's sending that limited data set. A local recording system can not only handle more data, but may be able to record after a 'damaging event' that isn't immediate total destruction - for example, it may be able to record the last actions the pilot took, which sensors failed, etc. - even if the comms are inoperable.",
"Maybe I’m underthinking this. But there are 87,000 flights everyday, in the US alone. (According to Google). That’s an incredible amount of data to handle. Especially given that in 99.9999% of the time it’s meaningless information.",
"It wouldn't need to be streaming constantly, but it should start a stream when any parameter is outside its normal values, or if the pilot presses his new \"emergency stream\" button.\n\nThis solves the problem with \"It's too much data to handle if all planes would constantly send everything\".",
"The biggest issue is the amount of data. One rolls Royce engine can generate terabytes if data. The F22 has a wire harness made out of optical fibers because copper simply didn’t have enough bandwidth to carry the amount of data that plane generates. Even if there were a bunch of multi band antennas at x-band (7-11ghz) our max throughput on one channel is 1-2gbps depending on data protection which needs to be high. The plane frequently generates much more than this. The thing that’ll get us there is laser data transmission. 900nm doesn’t absorb super well in atmosphere so you could use it for long range data transmission at insane rates. (Frequency is about 300ghz) and that could do it but the infrastructure will be highly complex and the range would still be lower than VHF and KA band which is what most planes use today",
"I work in data science. \n\nReal Time is already a pain for companies as they need quite an infrastructure, internet connection and the software to actually handle it. \n\nI doubt planes could do such thing as they need to stream a lot of data, have some zones where they can't contact any tower and be detected by one. \n\nTrains on the other hand are much more likely to have a live stream system (see Trenitalia and SAP S/4 Hana).",
"In an episode of Doctor Who, the black box was reconceived as a home box for spacecraft--it flew itself home to make sure the flight data was preserved. Scifi? For now. But with our drone technology improving, maybe in 100 years its an idea that could be considered? Even if it doesn't fly to a location but just ejects and lands safely nearby.",
"Because satellite internet can't do anything in real time, and having a plane talk to 1 or 2 satellites is really hard and there's no network on the ground a plane can reliably stay in contact with. Radio networks lack the bandwidth.\n\nHowever if starlink is a success when SpaceX launches it, this could change everything.\n\nSpaceX will likely engineer a satellite array specifically designed to be installed on aircraft.\n\nThis would give every aircraft in the sky access to one gigabit per second of Internet bandwidth at less than a hundred milliseconds of latency.\n\nSpaceX's starlink could really change everything.",
":Wave: - I worked in the industry on this issue, a few thoughts to offer.\n\nThe aviation industry is not one single well aligned entity - there are many players, companies, manufacturers, jurisdictions, laws new and old, regulations, and airlines all coexisting, but not always talking on the same wavelength. While it might seem easy to solve something, keep in mind the many many moving parts of aviation take time to discuss, agree, validate, implement, and correct any changes to the fleets. These are also necessarily expensive changes because of the scale and complexity of the efforts involved. Keep in mind, Aircraft have to fly all over the wold, often through airspace where countries may not even agree on what time it is. Even for something as simple as time, it gets complicated.\n\nThere have been manufacturers that have instrumented commercial aircraft typical of a normal passenger type that have generated in excess of 1.5 TB of data per hour of flight, this would be 'normal' data-points, useful for a flight incident, along with more frequently useful fleet maintenance and operations work. For example even if a part should still be good, this data can help predict a part failure and maintenance schedules could be adjusted to make sure parts are available, and ready for the work to be completed efficiently.\n\nBut as has been discussed in this thread, with the given context above, the real issue stems from bandwidth and coverage. Put simply, we don't have enough of either to get all the black box data off the plane - There are existing standards for smaller sets of data to be beacon'd out of the plane, which is typically refereed to as ADS-B. These data payloads contain things like aircraft status codes, location, aircraft identity, and a few more basic things. But this is not the entirety of the black box. There have been many standards, some more successful than others, and a great many minds have thought about this problem.\n\nThere are really two things the industry is trying to solve - one - the increased quality and frequency of ADS-B messages to avoid lost aircraft, but also less dramatically to solve much more common day to day problems - like trying to estimate when a heavy aircraft is actually going to arrive versus the scheduled arrival time at an Airport when coming over a long ocean flight for example. The airport likely won't know where the plane is exactly, until ATC sees that plane on radar or receives ADS-B data to confirm locally at that airport. This can be really useful to know a plane is 10 minutes late or early to help shuffle things around at gates for example.\n\nThis will be worked on with additional terrestrial receivers, as well as satellite receivers. [_URL_1_](_URL_1_) Is a prime example of the industry effort to collect more ADS-B data. This effort is costing billions of dollars, and each plane needs often millions of dollars of retrofit to support this. It'll take time for this to roll out - with typically more priority for international flights that need that extra coverage.\n\nSecond - the Black Box - this contains much more data about the plane than ADS-B would communicate, and it has a lot of value outside of incident reports. - There are efforts to add data cables to the gate umbilical that is used when an aircraft is at a gate so diagnostic data can be pulled off the aircraft and used for all sorts of beneficial scenarios, but this is typically something like a 10GBe Fiber Optical connection that tries to extract the data as quickly as possible while the plane is at the gate, and there could be a few TB of data to extract. This isn't easy, and not always available at many airports.\n\nSo to put it lightly - it's complex. Aireon in part was supported by ICAO so we could get some additional data on airplane locations, but keep in mind, many of these satellite constellations are less expensive low orbit units, and not geostationary ones, which means that the time the aircraft can be in range of line of sight to a microsatelite is limited. Still useful, but limited, and many aircraft may only see one of these satellites reliably to communicate once and hour, or perhaps a little more than that - but we are a long ways away from having a once a minute datapoint from all aircraft worldwide. And even farther from the TBs of data coming from each plane in flight, of which we have typically 6000-10000 flights in the air throughout the day.\n\nThat said, there is a lot of data out there, and if you'd like to look at it, check out this free ADS-B project and dataset: [_URL_0_](_URL_0_) (And specifically look here: [_URL_0_network/explorer](_URL_0_network/explorer) )",
"The reason is economics, not science.\n\nCost v. benefit. There would be a high cost to implement such a system wide change. For very little benefit. The current system works very well for its purpose save a few outlying but highly publicized cases. Since the demand is so low, the price the market will dictate does not exceed the cost.",
"As someone who works in the realm of networking I would assume it's because there just aren't persistent communication points available (satellite is out of the question because you have to aim for it, planes fly too high to reliably pick up cellular comms). You might be able to design something that once you get back into cellular range - it could backfill data. \n\n\nOne day you may be able to build some type of mesh network out of planes over populated areas but they'd still be unreliable over the ocean.",
"It costs money. \n\nAirline profit margins are typically lower than many other industries (where 9% to 12% can be considered amazing years). When the industry is dividing cabins in creative ways to eek out more profit, they’re not interested in voluntarily (not being mandated by the FAA) spending money or adding weight. Especially for something that is a statistically rare occurrence.",
"There are now satellites which receive ADS-B data over oceanic and other sparsely populated areas. Each aircraft transmits location and various flight parameters every few seconds. In the United States, the FAA made ADS-B transmitters a requirement for all aircraft in most U.S. airspace on January 1st, 2020. FlightAware has ADS-B satellite data, but currently charges a fee for access to it."
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"https://en.wikipedia.org/wiki/Flight\\_recorder"
],
[],
[],
[],
[],
[],
[],
[],
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"https://www.wsj.com/articles/new-black-boxes-offer-ability-to-send-real-time-data-from-plane-crashes-11549535520",
"https://aerospace.honeywell.com/en/learn/about-us/press-release/2019/02/honeywell-and-curtiss-wright-to-reinvent-black-box-recorders"
],
[],
[],
[],
[],
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[],
[],
[],
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[],
[],
[],
[],
[],
[],
[],
[],
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"https://opensky-network.org/",
"https://aireon.com/",
"https://opensky-network.org/network/explorer"
],
[],
[],
[],
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|
5shxpk | how does a "word" become a word? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5shxpk/eli5_how_does_a_word_become_a_word/ | {
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"A word becomes a word when people use it and other people recognise and understand it. As simple as that.\n\nDictionaries are just books, written by people. They put words and definitions for them into the books as they become common enough to need looking up.\n\nThe word \"quiz\" was famously popularized by a man trying to win a bet. [\"Quiz: what is it?\"](_URL_0_) \n\nShakespeare famously invented dozens of words, many of which are still in use today. "
]
} | [] | [] | [
[
"https://en.oxforddictionaries.com/explore/what-is-the-origin-of-the-word-quiz"
]
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||
sc754 | Can someone please read & rebut this? | askscience | http://www.reddit.com/r/askscience/comments/sc754/can_someone_please_read_rebut_this/ | {
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"The article hits upon a truth but takes it to the wrong conclusion. \n\nThe common theory (what most people are taught in school) is that random mutations and selection over time caused humans to evolve from amoebas. This is wrong, and the article points out the problems with this theory.\n\nHowever, evolutionists have done great work in the past few decades to fill in many of the gaps in our understanding. We now know that random mutations are actually much less a factor (possibly almost none) in evolution than originally thought. Things like recombination, epigenetics, multilevel selection, and plasticity play a much more significant role in driving evolution.\n\nBasically, we evolved methods to help us evolve better."
]
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[]
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||
3nm2kp | How good are people at picking random numbers? | Asking a group of people to pick random numbers (say 5 numbers, each 1-100) vs a random number generator, will they get a similar number distribution, or do people tend to avoid/favour picking specific numbers? | askscience | https://www.reddit.com/r/askscience/comments/3nm2kp/how_good_are_people_at_picking_random_numbers/ | {
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"People like to pick odd numbers, in particular prime numbers (at least when asked for small numbers like 1-20, but to some degree it should still be notable with 1-100). Also, randomly produced numbers/data often does not look random to humans, they spot some kind of pattern. Accordingly, when asked to generate something random, humans try to avoid said patterns and end up trying way too hard.\n\nThe question is probably better asked at \"Psychology\" though, since it's all about the human element and how humans perceive numbers, not about numbers themselves or a solvable math problem.",
"Humans are biased. A number of studies so far confirm that humans are not a good source of randomness. A couple to get you started:\n\n* W. A. Wagenaar (1972). \"Generation of random sequences by human subjects: a critical survey of the literature\". Psychological Bulletin 77: p65–72\n\n* Brugger, P. (1997). Variables that influence the generation of random sequences: An update. Perceptual and Motor Skills, 84(2), 627-661.\n\n* Persaud, N. (2005). Humans can consciously generate random number sequences: A possible test for artificial intelligence. Medical hypotheses, 65(2), 211-214\n\nattempted to be reproduced by:\n\n* Figurska, M., Stańczyk, M., & Kulesza, K. (2008). Humans cannot consciously generate random numbers sequences: Polemic study. Medical hypotheses, 70(1), 182-185\n\n* Towse, J. N., & Neil, D. (1998). Analyzing human random generation behavior: A review of methods used and a computer program for describing performance. Behavior Research Methods, Instruments, & Computers, 30(4), 583-591",
"You might also find [this paper](_URL_0_) (PDF) interesting, describing an exercise I have conducted with students in the past, with consistent success: ask one person to actually flip a coin, say 100 times, and write down the result of each flip; now ask n-1 others to write down 100 heads/tails results of what they *think* a random sequence of flips might look like.\n\nGiven all n sequences of 100 flips, the one with the longest run of consecutive heads (or tails) is very likely the \"really random\" one. Humans tend to underestimate the likelihood of a sequence of independent Bernoulli trials yielding the same outcome many times in a row.\n"
]
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[],
[],
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"http://gato-docs.its.txstate.edu/mathworks/DistributionOfLongestRun.pdf"
]
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|
11svfe | What causes the increased capacitance with decreased separation between plates? | I understand why potential difference relates to distance between plates, and that larger plates will mean more capacitance, but what is happening (on the atomic or ionic scale) to cause the capacitance to increase with decreasing distance? | askscience | http://www.reddit.com/r/askscience/comments/11svfe/what_causes_the_increased_capacitance_with/ | {
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"I like to think of Capacitance as \"the ability to store energy\"...larger capacitance means it can store more energy. If you take two plates that are oppositely charged, they are attracted to each other. The closer they are together, the more attracted they are to each other...which corresponds to more energy.",
"Capacitance is defined as charge per voltage. A large capacitance means that you can store a lot of charge per voltage, and a small capacitance means you can store very little charge per voltage. Further, in most cases the capacitance of a system is defined purely by its geometry, and it doesn't change depending on how much charge you have.\n\nIn general, the way to figure out something's capacitance is to imagine you have a certain charge Q+ on one plate and Q- on the other plate, and then calculate the voltage difference between the two plates. For your parallel plate capacitor, this calculation is fairly straight forward, as the voltage is just the electric field times the distance between the plates (or, generally, the integral over the E dot ds). Thus for Q+ and Q- a small separation between the plates will mean a smaller voltage compared to a large separation (the separation doesn't change the E field except on the edges of the plate). Therefore in the low separation case you can store the same amount of charge at a lower voltage, which is the definition of increasing your capacitance."
]
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[],
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|
2dkkxw | If all the rivers leading to oceans slowly wash dirt into the sea, will there eventually be no dry land? | Water evaporates, forms clouds, and then rains. Some of that rain evaporates again, but some of it will go into tributaries, streams, and rivers. Some of those will go into the sea. The water going into the sea washes dirt away with it. Will this process on a large enough time scale level out all the dry mass till the entire planet is encased in unbroken water? | askscience | http://www.reddit.com/r/askscience/comments/2dkkxw/if_all_the_rivers_leading_to_oceans_slowly_wash/ | {
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"Erosion is only half of the equation. Mountains are also being slowly formed by the action of plate tectonics, driven by the heat of the earth's core. Today's earth is in a near steady-state balance between erosion washing the continents away and plate tectonics pushing up new ground. In the long term, when earth's core cools and plate tectonics cease, than it would be possible for erosion to gradually remove all the land masses."
]
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|
24ax4g | the difference between "created" gems and "dug 'em out of the ground" gems | I've done some googling and basic research, which all points to "Created gems are identical to Natural gems, except they are generally cheaper with a higher quality than Natural gems."
However, I have female friends who claim that Created gems are terrible/trash/awful etc. So I'm confused. Are they delusional, or is the internet lieing to me again? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/24ax4g/eli5_the_difference_between_created_gems_and_dug/ | {
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"Did you mean to say that your friends claim that created gems are bad? Regardless, they're wrong.",
"Natural gems do often have some imperfections, because synthetic gems can be made to such quantity that defects are negligible.\n\nSome people like the imperfections, they like a cloudy diamond, or gem that has a crack on the interior.",
"It takes a trained/experienced jeweler to spot the difference between a synthetic and a natural gem. In fact, for the benefit of inexperienced jewelers, synthetic gems often actually have a serial number imprinted in the crystal as a \"this gem is synthetic\" notification.\n\nIn fact, as other commenters have pointed out, synthetic gems are often *more* flawless than natural gems, because they're created by tightly controlled lab processes rather than chaotic, unpredictable natural ones.\n\nThe anti-synthetic-gem movement is nothing more than a marketing ploy by the gem industry, because if lab-grown gems get popular, their profits could drop.",
"All of the other comments saying there is no difference besides being more perfect are correct. \n\nThat said, it is an issue for some gems where perfection isn't the point. For example, opals are highly prized because each one is unique in coloring, layers, and pattern. It is very easy to distinguish a synthetic one because they look like stained glass or have a snakeskin pattern that is very ordered and repetitive. Real opals tend to have swirls of color on distinguishable layers, visible through a semi-transparent or milky white texture. \n\nTo make it ELI5, opals are like unique marbles carved out of big rocks that are collectible because they're all unique. Synthetic opals are manmade marbles that have a lot of the same pattern and are really pretty, but don't really have a uniqueness to them. ",
"I do a bit of hobby gemcutting, and my wife is a jeweler. Lab created gems are generally more flawless, and are manufactured in the very best colors, and for top tier, large stones like ruby, sapphire, or chrysoberyl, natural stones are worth *ten thousand times more per carat*\n\nGems are a status object, like designer clothing or fine art. You can go to the flea market to buy knockoff designer clothing, it is \"worth less\" even though the difference may be subtle. [Art experts debate endlessly whether a particular painting is a work of a master](_URL_0_), his apprentice, or an imitator, and the expert consensus adds or subtracts tens of millions of dollars from the price of the painting, regardless of how pretty the thing is to look at. I think gem collectors are some of the least arbitrary of all status object collectors, they use gemological insturments and a great deal of deduction to determine whether the stones they examine are \"real\" or \"fake\", I find it fascinating in a way that discovering a fake Gucci purse isn't.\n\nAs a cutter, there is no artistry in cutting synthetics, there are no flaws to work around and the material is cheap enough that you aren't trying to save every fraction of a carat. But the artistry of cutting isn't a big contributor to price.\n\nBlue topaz is an interesting case of the grey area between \"real\" and synthetic, [99% of the material on the market is colorless natural topaz that has been irrradiated to make it blue.](_URL_1_) A jeweler should disclose the treatment, although few do. I have personally watched my wife explain that one piece of handcrafted jewelry features a natural stone with radiation enhanced color, and another is fully lab created, people generally choose the enhanced one."
]
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[],
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"http://en.wikipedia.org/wiki/Portrait_of_a_Young_Fianc%C3%A9e",
"http://www.nrc.gov/reading-rm/doc-collections/fact-sheets/irradiated-gemstones.html"
]
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|
1dnjk6 | In regards to magnetic levitation, can a weak magnetic field's strength be made up for with a stronger magnetic field? | askscience | http://www.reddit.com/r/askscience/comments/1dnjk6/in_regards_to_magnetic_levitation_can_a_weak/ | {
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4yvci6 | How was the 'Nestorian' church viewed by western Christians in the sixth century? | After the disputes of the fifth century, how were 'Nestorians' viewed in the west? Within the eastern Roman empire, a lot of time was spent on the argument between Chalcedonians and non-Chalcedonians, but Christians in the post-Roman west largely did not have to deal with that - how did they characterise the Church of the East, and how accurate were their information given the distance between them? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4yvci6/how_was_the_nestorian_church_viewed_by_western/ | {
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"I don't know the answer to this but I wanted to applaud for an excellent question, I didn't know how much I wanted to know about Nestorian until I read this post. ",
"Great question! As you seem to know; the 'Nestorian' Church was only called that by the \"western\" Church, as they identified themselves as the Church of the East or the Assyrian Church of the East. When I now said \"western\" Church, I need to specify for those who might equate it with the Catholic Church, because in the sixth century the western Church includes the Orthodox as well. Though, speaking in those terms, \"Orthodox\" and \"Catholic\", is sort of anachronistic at that time. In the sixth century there is still one church with certain communities in the East starting to withdraw from the ecumenical councils as they did not agree with the compromises made there. Though, in the sixth century, the Church of the East was not completely out yet. To understand how the western Christians viewed the 'Nestorian' Church in the sixth century, we have to first understand the name \"Nestorius\" and what the westerners understood by that, second we need to understand the divide that started at the Council in Chalcedon in 451. \n\nNestorius was the Archbishop of Constantinople who got condemned at the council of Epesus in 431 for speaking of a christological doctrine that was too much for the rest to swallow. What he proposed was that there were to Persons (hypostases) in Christ; the Divine and the human. This had nothing yet to do with the Eastern Church. How could it? Nestoruis was a man from Constantinopel who spoke greek, and the language of the Eastern Church was syriac. Nestorius would become a somewhat prominent figure in the Eastern Church. The important thing here is that Nestorius were not condemned by the Eastern Church, and that his name \"Nestorius\" was used in the western part of Christendom as a label of insult to attack opponents. \n\nWe now jump ahead to the council of Chalcedon (451). This is where the Church of the East will part from the Church of the West, but not of reasons that you'd think. Because, as Sebastian P. Brock has argued for brilliantly, it seems that the reason was bad communication. I said earlier that the Church of the East spoke Syriac, and in the west it was mostly communicated in Greek, especially in these councils which were held in the Byzantine territory. At the council of Chalcedon there were a discussion about faith. The council was discussing if there were two hypostases in Christ or just one. Three key terms were then crucial for the discussion: nature, hypostases and person. \n\nBrock argues that these were difficult words to translate from greek to syriac. The greek word hypostasis were translated to the syriac word qnoma. The problem here is that the syriac word of qnoma has a much wider range of meanings and would in english translate closely to \"individual manifestation\". Qnoma has again traditionally been understood wrongly as \"person\". This has then finally led to the classical definition of Nestotianism as \"the belief in two persons in Christ\". \n\nAs you see, the Church of the East became an easy target for the rethoric of the west in this trublesome communication. The differenses were really not to big between the two, but the language barrier was the deal breaker. So when you ask: how was the 'Nestorian' Church viewed by the western Christians in the sixth century? It is tempting to answer: \"wrongly\". The more correct answer I think would be that they lost contact, but the image remained. These were the people who believe that Christ had two hypostasis: one divine and one human. \n\nSources: \nBROCK, Sebastian P. (1996) The \"Nestorian\" Church: A Labmentable Misnomer. In \"Bulletin of The John Rylands Library\", vol. 78, nr. 3, pp. 23 - 35. \nBAUM, Wilhelm & Winkler, Dietmar W. (2003) The Churches of the East: A Concise History. London. Pages: 204.\n\nEdit: A lot of spelling. I was kind of in a hurry when I wrote this."
]
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48q2sq | Why did Pike formations become so popular in the 15th century? And why didn't people in Pike formations use shields? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/48q2sq/why_did_pike_formations_become_so_popular_in_the/ | {
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"A compact group of men with lots of pointy sticks is very difficult to attack frontally, and before rapidly reloading firearms were developed, was the most popular way of fighting. You might be familiar with the [ancient Greek phalanx as used by the Macedonians](_URL_5_). A compact spear formation is what Alexander used to create his empire, even if as a consequence of compactness it is very difficult to maneuver (the phalanx is easy to flank, [which is why you need a lot of spears as well as a degree of combined arms for a Greek phalanx to be effective](_URL_7_)).\n\nThe prevalence of Pike weapons in the early modern period isn't so shocking because of their sudden appearance (pole-arms had always been around, their evolution into pikes and halberds and their [dozens of variations](_URL_8_) isn't particularly shocking), but their effectiveness unsupported as disciplined professional soldiers started to use them is, relegating cavalry to a much less decisive role in warfare. \n\nUnsupported infantry had [repulsed cavalry in the past](_URL_3_) on multiple occasions. However, none had a better reputation for doing so consistently than Swiss Pikemen, who [had been repelling Austrian incursions for a long while](_URL_0_) as well as [repelling Brugundians](_URL_1_). The difficulty to invade the Cantons that formed the [Old Swiss Confederacy](_URL_4_) and their system of local militias organized to defend themselves not only certified Swiss Independence, but also made it such that poor men who knew little but how to fight (and do it well) were soon in demand in France and Italy. \nThe Valois kings of France were especially dependent on the discipline of the Swiss mercenaries, who would form the center of the French line and spearhead the attack with a steady steamroll of pointy sticks. \n\nThe demand for mercenaries was also fed by the early emergence of the state apparatus: as the government of the Italian Communes became governments of sovereign states and the King of France imposed himself on his feudal subjects, the state treasury became a more rapid and efficient way of raising an army as opposed to armies composed of men who owned arms and armor as a consequence of land ownership and fought out of nebulous feudal obligations. \n\nWhy didn't they use shields? [Pikes are very long](_URL_2_) and heavy (so they don't shatter under a cavalry charge), they can only really be held with a [two-handed grip](_URL_6_). \n\n"
]
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"https://upload.wikimedia.org/wikipedia/commons/5/55/Schlacht_bei_Dorneck.jpg",
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"https://www.reddit.com/r/AskHistorians/comments/3rnlv0/what_were_the_roles_of_the_individual_city_states/cwq4xm8",
"https://upload.wikimedia.org/wikipedia/commons/f/f1/Territorial-development-Swiss_Confederacy.png",
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"https://upload.wikimedia.org/wikipedia/commons/1/1b/Pike_square_img_3655.jpg",
"https://upload.wikimedia.org/wikipedia/commons/d/df/Macedonian_battle_formation-en.svg",
"https://www.reddit.com/r/AskHistorians/comments/46jfl8/did_1314th_century_european_foot_soldiers_employ/d05thqs"
]
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||
63h0e7 | Did Hitler have a cult of personality? | I recently argued with my history teacher about this. I said he did, with evidence in things like his picture being framed in classrooms, etc,. Would this be true? If so, are there other examples I could present that he in fact did have a cult of personality? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/63h0e7/did_hitler_have_a_cult_of_personality/ | {
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"Follow-up question, in films set during the Third Reich, it's common to see \"Heil Hitler\" portrayed as having become a fairly ordinary greeting in Germany. Did normal, pro-Nazi civilians really use that in everyday life to nearly the degree as in popular culture? ",
"Nazi Germany **definitely** had an enforced cult of personality around Hitler.\n\nMore examples besides 'Hitler picture in every classroom':\n\n* 'German Salute' with an exclamation of 'Heil Hitler' was de facto mandatory for every citizen. 'Heil Hitler' also replaced \"Mit freundlichen Gruessen\" ('with kind regards') as the standard phrase to end a letter. Refusing to comply with this could bring someone into serious trouble.\n* Soldiers were sworn in directly onto the person of Adolf Hitler himself. The oath translated: \"I swear to God this sacred oath that to the Leader of the German Empire and people, Adolf Hitler, supreme commander of the armed forces, I shall render unconditional obedience and that as a brave soldier I shall at all times be prepared to give my life for this oath.\" (Edit additional information:) This became a serious psychological barrier for the resistance movement inside the Wehrmacht. A lot of officers were reluctant to stage a coup against Hitler because they had sworn this oath.\n* Countless towns renamed important streets and plazas to \"Adolf-Hitler Strasse\" or \"Adolf-Hitler-Platz\".\n* The youth branch of the Nazi party, where membership was mandatory for every young german, was named \"Hitler Youth\".\n\nIn a nutshell: In Nazi Germany, it was \"Hitler, Hitler, Hitler\" **everywhere**. Besides the Soviet Union under Stalin, Nazi Germany is one of the textbook examples of a cult of personality.\n\nThe German Historical Museum has an online exhibition on history and daily life under the Nazi dictatorship, unfortunately in german language, for sources on these examples, and more:\n\n_URL_0_\n"
]
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[],
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"https://www.dhm.de/lemo/kapitel/ns-regime/alltagsleben.html"
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8z6fup | Revolutionary War | Why is it that the American Revolutionary War was fought with significantly smaller armies when compared to those fought in the Napoleonic wars just a couple of decades later? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/8z6fup/revolutionary_war/ | {
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"One question is why the British allocated so few men and so little materiél to crushing the colonists' revolt. First, in the years 1776-1781 Britain had other opponents than the Continentals and was fighting in other places. At the same time that Britain was engaged in trying to catch and defeat George Washington's army, it was also engaged in related conflicts with the French, Spanish and Dutch and fighting what was to be a series of military campaigns that eventually led to British control of India. Second, the 13 Colonies were of lesser economic concern. If the Caribbean colonies had tried to become independent, the wealthy sugar plantation owners living in England (known as the Nabobs) would have pushed the government to fight much harder and longer to prevent it. Third, there was a British reluctance to get into another big fight. It had only recently finished the exhausting Seven Years' War twelve years before ( initially the American Revolution seemed to be a limited revolt by the colonists against paying for that ) and this time didn't have the Prussians to help. There were within the government voices of dissent, like Isaac Barré, who could reasonably denounce the War as a bad idea.\n\nFor the small Continental forces, there's the simple matter of population. The 13 Colonies had maybe 2.5 million people , mostly somewhat poor farmers, spread out over a very big piece of territory. They could and would only field a small force. The Continental Army they raised was never more than around 17,000- and the turnover within that was high as the War dragged on. Washington continually begged for men and supplies and didn't get them. If the French hadn't provided both, Britain likely would have won.\n\nIn contrast, the Napoleonic Wars were mostly fought in Europe, and with European forces from many European countries. Their populations were much larger, their soldiers didn't have to be loaded onto ships and sent across the Atlantic, and the stakes were much higher: for most of them, it was a battle for survival, to avoid being conquered by Napoleon.\n\nAlan Taylor: *American Revolutions*"
]
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[]
] |
|
4ucb1x | What is the visual difference between nearsightedness and astigmatism? | I have both, and they're both pretty bad. For many years, I still have not figured out if what I'm seeing is mainly a result of my astigmatism, my nearsightedness, or some combination of both, which leads me to question what a person sees with only one of myopia or astigmatism. Some pictures or illustrious wordage would be wonderful in describing what the difference is.
(I kind of understand the optical/light part of it. I don't really understand the results part of it.) | askscience | https://www.reddit.com/r/askscience/comments/4ucb1x/what_is_the_visual_difference_between/ | {
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"text": [
"Shortsightedness is a result of the eye focusing light in front of, instead of right at, the retina. The light comes to a focus, but then spreads out again before it hits the retina, so what you see is blurred.\n\nAstigmatism is, roughly, a difference in where light gets focused depending on the angle at which the light hits the lens.\n\nYou can imagine focusing to be like a cone coming to a point. If you can imagine it, think of how the cone can be sliced up into circles, each one getting smaller, until you get to a focused point. Now imagine that it never comes to a point; instead, the slices start to get more and more elliptical. Eventually you get to a slice where the width (for example) is close to zero (focused) but the height hasn't yet come all the way down. If you keep going, the \"width\" will cross over itself and become unfocused again, until you get to the point where the \"height\" finally gets to zero.\n\nSo astigmatism might mean that while you can get perfect focus on vertical lines, you won't be able to focus on horizontal lines. A plain circular lines might correct the horizontal lines, but then the vertical lines would be blurred. So you need an astigmatic lens to correct for the astigmatism of the eye.\n\nIf you only had myopia, things would be blurred into perfect circles. I'm not sure you can really \"only\" have astigmatism - you might be able to focus perfectly on, say, 60 & deg; lines, but everything else will be varied amounts out of focus.\n\nHere's an image that might help. See how the different angles of light focus in different places (there will be a continuous change between the two):\n\n_URL_0_"
]
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[
"http://www.daviddarling.info/images/astigmatism.jpg"
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4slvcw | Did Roman veterans get to keep their weapons and armour at the end of their service? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/4slvcw/did_roman_veterans_get_to_keep_their_weapons_and/ | {
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"Virtually all the evidence for this questions is from the Imperial period, after the Roman Army had become regularized. That is -- the first century CE and after. We have good sources for how Imperial soldiers were paid and equipped. The basic answer is that the Roman State provided new recruits with all their basic needs, including clothing and food, but these items were deducted from their pay. There are many itemized documents indicating these deductions (see #1 below). In none of these are weapons or armor specifically mentioned. Nevertheless, the evidence seems to suggest that the average soldier was provided his weaponry by the Roman State upon recruitment and the cost of these items were deducted from his pay, including weapons. Tacitus mentions as much (see #2). It is unclear if that meant they \"owned\" the state-provided weapons when they were discharged, and no source I can find mentions a soldier going home with his *lorica* or *pilum.* We know that many permanent Roman forts along the frontiers had workshops (*fabricae*) to produce or mend weapons and tack. These were usually small and seemed to be intended for maintenance, but one at Corbridge was very large and may have been a weapons factory for State use. Otherwise, the production of weaponry was left to the private sector, but with the State owning a virtual monopoly on the use of heavy weapons, it must have largely controlled the price. I think we should imagine larger orders, and usually only when disasters happened or new units were being created. It is difficult to imagine how arms production would have worked, if discharged soldiers were carrying off their equipment. Perhaps they \"sold\" it back to the legion when they left, but I can find no evidence for anything like this. The soldier was also free, however, to supplement or replace these basic weapons and clothing with his own, if he wanted. Pliny the Younger tells us in a letter (*Ep.* 6.25.3-4) that he gave a centurion named Metilius Crispus 40,000 sesterces for the purchase of equipment. He must have looked very fancy on his way to war, because he never arrived, probably ambushed by robbers. \n\nThe basic 'uniform' (*habitus*) of the Roman soldier in all periods was the sword belt (with *pugio* dagger), and we hear of severe punishment for soldiers who went *discinctus* 'unbelted' in the field; going unbelted was often associated with a soft life, or effeminacy (Tacitus *Ann.* 13.35; Fronto *ad verum Imp.* 2.1.19; cf the encounter in Petronius, *Satyricon* 82). This might suggest a more personal connection between a soldier and his sword/dagger, at the very least. But never do we hear about \"named\" swords, or soldiers wielding antique weapons. The Roman gladius was a durable object, and if properly maintained would have lasted for centuries. In the Republican period, there had to have been legacy weapons in the aristocratic families, yet I can't recall any evidence or mention of family swords, antiques, or anything like this. -- It suggests to me that Roman culture did not fetishize weapons as later cultures would -- there is no Roman Excalibur, no Joyeuse, no Balmung, no Durandal, no Hrunting. If a soldier carried home his sword after he was discharged, I don't imagine it was from any romanticized attachment, even if he carried it for decades. He may have thought of it as just a tool, like his shovel or his spoon. If he did bring it, it might have been more about maintaining his identity as a military man. Sara Elise Phang has an interesting chapter on this subject (*Roman Military Service: Ideologies of Discipline in the Late Republic and Early Principate* 2008, chapter 3).\n\n\n & nbsp;\n\n & nbsp;\n\n**1)** From a papyrus from Masada (Israel), 72-75 CE (Cotton and Geiger 1989:722)\n\nIn the fourth consulship of Emperor [Ves]pas[ian] Augustus (?)\nPay Account (?)\nGaius Messius, son of Gaius, of the Fabia tribe, from Berytus\n\nI have received as my salary 50 denarii\nout of this I have paid:\n\n\nbarley [ _ _ _ ]\n\n[ _ _ _ ]rnius\n\nfood. . . 20 denarii\n\nboots. . . 5 denarii\n\nleather straps (?). . . 2 denarii\n\nlinen tunic. . . 7 denarii\n\n\n\n & nbsp;\n\n\nI have received as my salary 60 denarii\n\nout of this I have paid:\n\nbarley ? . . . denarii\n\nfood . . . 20 denarii\n\nGaius Antonius\n\nheavy cloak . . . ? denarii\n\nPuplius Valerius\n\nwhite tunic . . ? denarii\n\n\n\n & nbsp;\n\n**2)** The historian Tacitus reports (annals 1.17) that after the death of Augustus, some soldiers in Pannonia put on a mutiny in protest of their \"working conditions\":\n\n > He (Percennius, leader of the mutineers in Pannonia) said that enough harm had been caused over the years by their passivity; old men, several of them with their bodies disfigured by wounds, were serving their thirtieth or fortieth year. There was no end to military service even when they were discharged, since they remained under the standards and performed the same toil under another name. And, if anyone survived all these perils, he was dragged off to a distant country where he received, in the name of a plot of colony land, some waterlogged swamps or uncultivated mountainsides. Indeed military service was relentless and unprofitable; body and spirit were valued at two and a half sesterces a day, and **out of this they had to pay for their clothing, weapons, and tents**, and bribe vicious centurions to escape routine drudgery.\n\n"
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6bfxd1 | do objects vibrating at their resonant frequencies break? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6bfxd1/eli5_do_objects_vibrating_at_their_resonant/ | {
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"Not always. Objects break when they vibrate with enough force to overcome their structure (regardless of why they're vibrating), and it's easier to do that when vibrating something at its resonant frequency, but you still have to generate enough force to break it. That's easy to do with something like a wine glass, which is relatively fragile, but is extremely difficult to do with something like a steel rod.",
"Usually not. For example, many musical instruments do this, and they don't break.\n\nHowever, if you keep adding more and more energy to such an object, making the vibrations bigger and bigger (or if it's just fragile), then it can indeed break. For example the old Tacoma Narrows Bridge collapsed this way (see YouTube video of it)."
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fv5d53 | Did the Māori still have a significant seafaring tradition by the time of European Contact? | It can be interesting reading about Polynesian peoples unique seafaring capacities, but I was just thinking to myself I rarely hear about it in relation to Māori people in New Zealand compared to places like Hawaii or Tonga. Am I just ignorant about Maori seagoing tradition, or were they comparatively more landlubbers than the rest of the Pacific? If not, the Maori have a famous martial culture, was water based warfare a major part of this? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/fv5d53/did_the_māori_still_have_a_significant_seafaring/ | {
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"Waka (Māori canoes) were still in widespread usage by the time Europeans arrived but were not used for long-distance ocean exploration. \n\nMāori are currently thought to have first arrived in New Zealand during the late 13th Century and settlement probably continued for several generations or more. By the time Europeans first encountered Māori, less than 400 years later, any contact with the other Pacific Island nations had long been lost. This is likely because New Zealand is relatively large and had plentiful resources so trade and long-distance exploration were not necessary and, given the large distances involved (the closest inhabited islands to New Zealand being well over a thousand kilometers away) would have been too risky and costly to be profitable. The Chatham Islands were colonized by Māori during the 15th Century, so some exploration presumably continued at least till then (and after that there was very little new land around New Zealand to even be discovered), but there is no evidence of continued contact between the two populations.\n\nIn the absence of oceanic exploration, waka still played a major role in Māori society. In particular they were frequently used for the transport of people and goods, being preferred to land travel. This took place on rivers and along the coast, not on the open ocean as with the other Polynesian peoples, given how much larger and more isolated New Zealand was. Fishing was also of great importance, being one of the main food sources for Māori. Fishing trips could be quite extensive, with one account (from post-European times) being given of a single expedition that consisted of 50 canoes and that caught over 7000 sharks, and frequently traveled far from shore to reach deep waters.\n\nWaka were also important in warfare as a form of troop transport, with the largest able to carry up to 100 soldiers. As far as I know, water-based combat was not common - as is understandable given pre-European Māori warfare lacked any form of ranged weapon so there would be no major advantage to naval warfare. One notable exception, however, was the ramming and boarding of one of Abel Tasman's boats, the day after first contact, by a waka which resulted in four European deaths and the waka escaping before any retaliation could be launched. Such an encounter suggests that naval combat wasn't totally foreign to the Māori, even if it may not have been common."
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sy1h5 | Is there any way to tell whether a star system contains a planet if we consider that that planet's plane of orbit does not allow us to witness a variation of the star's luminosity as the planet passes over it? | Planets can only currently be known to exist in remote star systems by the observation of the star's varying luminosity as the planet passes between over the star's surface facing Earth.
If the planetary orbital plane of a system would restrict planets from passing the line drawn between that star and Earth, e.g. if the planetary orbital plane's normal faces Earth, would there be any method that could be developed to determine the existence of planets in that system? | askscience | http://www.reddit.com/r/askscience/comments/sy1h5/is_there_any_way_to_tell_whether_a_star_system/ | {
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"The question suffers from a fundamental flaw. Namely, that's not the only way to discover extrasolar planets. It was the earliest, but its been more then a decade since it was the only kid on the block."
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13yhta | the difference between "entropy", "enthalpy", and how they relate to gibb's free energy. | I know that these two terms are closely related, so what is it that makes them uniquely different? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/13yhta/eli5_the_difference_between_entropy_enthalpy_and/ | {
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"Entropy - measure of the disorderliness of a system. If you had a box of toys in a box and took them out and played with them, at the end of the playtime your toys would be scattered all over the place. It's more disorderly now, so the entropy change would be positive. (Not exactly right, but for a 5 year old it will suffice) \nPositive entropy change indicates an increase in disorderliness and vice versa.\n\nEnthalpy change - change in energy. The energy/enthalpy of a system cannot be measured per se, just the change in energy. Let's say I'm running and sweaty and all hot. I give out energy in the form of heat, so my enthalpy change is negative.\n\nBoth entropy and enthalpy are measured in kJ per mol. You cannot measure the exact entropy or enthalpy of a closed system, only CHANGES in entropy or enthalpy.\n\nNow the equation: ΔG = ΔH - TΔS \nWhere ΔG = Gibbs Free Energy \nΔH = enthalpy change \nT = temperature in Kelvin \nΔS = entropy change\n\nWhen ΔG < 0, that reaction is spontaneous at that temperature. You can see that having a low ΔH and high T/ΔS would favor the spontaneity of a reaction, although it is not always guaranteed.\n\nI've tried to be thorough enough, but for a more comprehensive explanation you should probably look at a textbook or possibly KhanAcademy."
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dsvrmo | How is detecting exoplanets via transit effective if some planets take decades or more to complete an orbit? | Or is the transit method only practical for exoplanets with an orbit within a reasonable timeframe? | askscience | https://www.reddit.com/r/askscience/comments/dsvrmo/how_is_detecting_exoplanets_via_transit_effective/ | {
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"The transit method is only practical for exoplanets with shorter orbital periods. It simply doesn't detect ones that takes years to orbit until you've been watching for a long time, which you can even see in the data directly if you plot all of the known exoplanets by orbital period [in this app hosting published values of exoplanet orbits](_URL_1_). Planets exist with longer orbital periods that just haven't been detected. Even if a transit has occurred while people were watching, multiple transits are required to establish a firm detection and an orbit.\n\nThat's one reason why some of the next generation of flagship space telescopes being designed now, LUVOIR and HabEx, focus on [direct detection of exoplanets with coronagraphs](_URL_0_).",
"That's not only true for the transit method, but also for all other methods: slow orbiting planets have either too little effect on virtually everything we can currently use to detect exoplanet, except for direct observation, or the detectable event occurs too rarely to effectively reveal the planet.",
"What about planets whose orbital plane is orthogonal to our position? (Said different, the vector pointing towards us from the star is the normal vector of the plane of the orbits of its planets). Are these planets detectable?"
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"http://exoplanets.org/plots"
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89kvnn | why do gamers use headsets? | Is that the main audio source? Dont they use speakers to hear the game sound?
Im not a hardcore gamer and when i play i use the speakers for sound so i never understood the use of headsets in youtube twitch and e sports.
Edit: thank you for your answers i didnt know. | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/89kvnn/eli5_why_do_gamers_use_headsets/ | {
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"So you can have voice and game audio at the same time. Also headsets can have 7.1 setups that actually help in games by allowing for truly accurate locational sounds. ",
"I use them when I'm also using the microphone to talk with other players. Otherwise I just use the speakers. ",
"They use headsets because in some games it gives players advantages. Like hearing where an opponent is coming from, or when a certain sound queues a unique action in game. Some players also just enjoy hearing the ambient music or fx within the game. It's also just courteous to the other people around the house who may be bothered by the sounds. ",
"The headset is both the audio source and the microphone they use\n\nHeadsets don't feed back into the microphone and provide much better sound directionality.\n\nNot feeding back into the microphone is important, it allows voice to come through clearly at reasonable volumes without distortion when in a big battle where there will be lots of sounds.\n\nSound direction is very important in figuring out where other players are located. If I have a pair of speakers then all sounds come from a variation of either in front of me to the left or in front of me to the right. Headphones with a good sound card and fancy software can simulate full surround sound giving you much better situational awareness, now instead of everything coming from the front you can have sounds come from directly left or even behind with some fancy processing.",
"Speakers and microphones do not mix, it causes alot of echoes and feed back. Its cheaper and more convenient to use headphones.",
"There are several reasons:\n\n- If you play in a \"needs to be quiet\" area, it will keep it quiet. For example having three kids playing different games will make it a battle to find out who can turn their speakers on loudest.\n\n- If you play with others, the sounds of others can confuse your perception of the game. Also if your surroundings are noisy, you will miss clues.\n\n- You will have a better chance of hearing sounds and hearing the 'direction' they are coming from. This will give you a game advantage.\n",
"Most \"competitive gamers\" use headsets as the sole source of noise.\n\nFor one, it's much easier to block our all noise except the game, so you can focus purely on the game. No hearing the neighbor mowing, or the AC kicking on, or etc. This also becomes a must as soon as two or more gamers are in the same room, you don't want to be hearing someone else's game noises and getting confused. \n\nAnother reason is that sound location can be reproduced more accurately. A game knows exactly where the speakers in a headset will be in relation to your ears, and good headsets can very accurately represent exactly where a noise should be coming from. But external speakers can be set up anywhere, and everyone has different size and shape rooms and height desks and setups. And often people only have speakers on the desk in front of them. So it's much harder to accurately represent where a sound is coming from with external speakers, especially if it's supposed to be behind or to the side of you.\n\nHeadsets also usually come with integrated microphones. Because the headset moves with your head, the microphone moves with your mouth and is always the exact same distance away from it, leading to a consistent sound quality. It's also much closer to you than a desk based microphone, so can have a much smaller pickup radius, so usually can be set to pick up much less external noise and works better with external noise canceling.\n\nAn added benefit is for streaming. If you stream your games, your microphone would usually pick up any game sounds you had on an external speaker, so it will either echo the game sounds coming directly from the game, or you'd have to not use the high quality directly from the game sound in your stream, and rely only on the sound from your speaker being re picked up by your mic, drastically reducing quality (think watching a clip of jeopardy on YouTube, vs watching a someone's recording of jeopardy on tv from a hand camera on YouTube) "
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5g3318 | why does santa claus go by so many names (st. nicholas, kris kringle, etc)? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5g3318/eli5_why_does_santa_claus_go_by_so_many_names_st/ | {
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"Santa Claus is an amalgam of dozens if not hundreds of different mythical/religious characters and a few actual historical figures. As such some of the names of those separate figures carried through to modernity as alternate names for Santa Claus. "
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fhc042 | why are absurdly misspelled scams circulated? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/fhc042/eli5_why_are_absurdly_misspelled_scams_circulated/ | {
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"From what I understand, they're written like that on purpose. It helps them immediately weed out the people who would be smart enough to figure out it's a scam partway through the process. The people who see all the spelling errors and don't immediately have red flags go up are generally gullible enough to go through the whole thing without catching on.",
"It's also to avoid automatic detection by spam filters. Often, they are randomly changed/generated, with spelling errors in random places."
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6gtb60 | why is russia still so influential? | [deleted] | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/6gtb60/eli5_why_is_russia_still_so_influential/ | {
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"The russian military has the power to take over nations bordering the EU in a matter of days. Really, the only world powers capable of stopping them are the US and china, and china likely would not intervene.\n\nThis basically lets Russia reserve the right to completely destabilize eastern Europe, even worse than they already have in the past 5 years (see ukraine, crimea and syria)"
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1a8cqk | How do insects and other seasonal organisms survive through the period where they aren't active when their lifespans are so short? | Many insects have a lifespan of a few weeks but somehow survive through winter or other unfavorable weather conditions. What kinds of biological mechanisms are in place so that this is possible? Are there many reasons for different species, or is there one major factor? | askscience | http://www.reddit.com/r/askscience/comments/1a8cqk/how_do_insects_and_other_seasonal_organisms/ | {
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"This period of inactivity that you have described is commonly referred to as diapause and can be broken down into five steps:\n\n* 1) Induction: At some point during development, the insect will be exposed to a number of token stimuli that indicate a likely shift in the environment, such as temperature or photoperiod. It is important to note that these factors have to be present over an extended period of time to truly induce diapause.\n\n* 2) Preparation: Although not present in all insects, this stage is usually characterized by an accumulation of metabolites in the fat body and the alteration of the cuticle (exoskeleton). Another common thing to see is an increased concentration of trehalose in the hemolymph (\"blood\"). This disaccharide is the primary blood sugar and can act as a cryoprotective agent in the insect by reducing the freezing point.\n\n* 3) Initiation: If the conditions are appropriate, the insect will now entire diapause proper and both development and metabolism will slow significantly.\n\n* 4) Maintenance: The diapause state is regulated by not only the prevailing environmental conditions (as we saw previously), but also internal factors as well. The neuroendocrine system, for instance, plays a fairly large role, depending on the developmental state. \n\n* 4a) In the embryonic state, diapause hormone leads to the breakdown of trehalose and the accumulation of glycogen derivatives, which actively inhibit development.\n\n* 4b) In larval and pupal stages, we often see either the production or reception of prothoracicotropic hormone (PTTH) decrease. This hormone produced by neurosecretory cells in the brain activate the prothoracic glands to produce ecdysteroids, the primary molting hormones. Without ecdysteroids, the insect cannot progress to a new molt. The presence of juvenile hormone (JH) is also quite common, as it is maintains the larval \"status quo.\"\n\n* 4c) In adults, PTTH is not present due to the prothoracic gland degrading during metamorphosis. JH, however, is still around, though at low quantities. At these low levels, the adults experience flight muscle atrophy and the cessation of mating behaviors.\n\n* 5) Termination: As with induction and initiation, the insect will leave diapause once they are exposed to a certain set of stimuli, such as temperature or contact with water (in the case of mosquitoes for instance) "
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25t48r | Are gigantic Earth-like planets possible? | I was just reading about the Gemini Planet Imager, and one of the scientists stated it couldn't pick up any Earth-like planets because they're too small.
Is there something preventing super-large rocky, molten-core planets in habitable zones? | askscience | http://www.reddit.com/r/askscience/comments/25t48r/are_gigantic_earthlike_planets_possible/ | {
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"If it gets too big, it starts to attract a lot of hydrogen and helium and it becomes a gas giant. ",
"So very large rocky planets are possible, it's generally thought that the upper-bound is around 10 Earth masses. This is for two reasons.\n\n1) Once you get larger than that, you start attracting a whole bunch of gas and water. Then you get a neptune or a jupiter-like planet\n\n2) There is a limit on the amount of rocky material in the planetary system. Hydrogen and helium are _much_ more abundant than Iron or silicates are.\n\nNow, the reason they can't pick them up is actually really interesting. If you double the mass of a planet the radius doesn't double. You might think that it would go up by a factor of 2^(1/3) (which would correspond to doubling its volume) but that isn't correct either. As it turns out it does up by less than that.\n\nThe reason is that as you make the planet more massive, the stuff at the interior gets compressed more and more because the pressures in the interior are higher. This means that the materials in the interior take up less space and the radius goes up by less than 2^(1/3).\n\nQuickly eyeballing a paper by Sara Seager (Mass-Radius relationships for solid exoplanets (2007)) it looks like a 10 Earth mass planet with the same proportion of elements as the Earth would have a radius about twice that of the Earth."
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4a9el9 | what effects do nitrites and nitrates contained in foods have on people? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/4a9el9/eli5_what_effects_do_nitrites_and_nitrates/ | {
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"Too high a dose of nitrates in a human can cause nitrate toxicity. The nitrate will oxidise the iron in hemoglobin leaving it unable to carry oxygen. Babies are especially vulnerable, with \"blue baby syndrome\" being the most common diagnosis.\n\nLong term exposure to nitrates has been linked to some types of colon cancer, but the effect is very weak.",
"Toxicity from nitrate consumption is rarely, if ever, *acute*, meaning immediately and dramatically a problem. Instead, the toxicity is from *chronic* exposure, meaning damage caused over time. Much like how very few people get acute radiation poisoning, but DNA damage due to exposure to radiation over time causes many cancers. \n\nAnd like radiation, nitrate consumption can lead to DNA damage. Nitrates can form what are known as \"nitrosamines\" in the presence of amines which are found in many compounds, include amino acids, the building blocks of protein. And indeed, it has been [found](_URL_1_) that dietary nitrates can form nitrosamines.\n\nNow, nitrosamines themselves are what pose a problem. They have been [known to cause cancer](_URL_0_) in humans for quite a while, and are thought to be one of the major cancer causing constituents of tobacco smoke. \n\nSo minor DNA damage at the best, cancer at the worst. I would just avoid nitrates where possible. There are also cardiovascular and respiratory (heart and oxygen-binding) effects, but they are transient.",
"believe it or not, we're not sure if they are good or bad for your body, or what they do. some scientists emphatically say that they are actually *required* for good health, as opposed to being bad for you. and most balanced diets will contain a much higher proportion of nitrite than you might imagine, a concentration likely to be higher than if all you ate was bacon and hotdogs. nitrates are prevalent in many root vegetables, for example, which are part of a healthy diet.\n\nsome studies have shown that nitrite in the blood dilates the arteries and promotes better blood flow (more [HERE](_URL_1_) ). these studies say that about three quarters of the nitrite in our blood is produced by our own bodies for this very reason (blood flow), and that the amount is way more than we get from processed meats.\n\nthe big bugaboo... the public generally has been led to believe that studies show that diets high in nitrite/nitrate added foods cause cancer. some studies do seem to show this.\n\nbut at the same time, foods which are also believed to be *healthy* for you, like celery and spinach, or beets, contain very high levels of nitrite and nitrates themselves. and these foods are found to reduce incidence of cancer. these natural sources contain VASTLY more nitrates than the hot dog or pastrami sandwich we may have told to worry about. how much more?\n\nwell, a serving of arugula (your salad, say) contains more nitrite than almost [500 hotdogs](_URL_2_). the same amount in four servings of celery have about the same amount\n\nand your own spit in fact contains as much or more nitrite as those nearly-500 hotdogs.\n\nso it is really unclear whether the bad reputation for nitrates/nitrite in processed food is deserved.\n\nif nitrates/nitrite are bad for you, then consider this: if you have a nice garden salad, while your friend indulges in four hotdogs and a whole pound of bacon, one of you is consuming healthier levels of nitrate/nitrite. (spoiler: it isn't you). but yeah, all that fat and salt in the dogs and bacon may not be so good either. \n\nthe biggest factor in your health would be the entire nutritional/dietary quality of the food itself within which the nitrite and nitrate is found. for example, is it healthier to eat \"uncured\" bacon? well, it's still salty meat and pork fat. how healthy is \"healthy\" when we are talking about bacon.\n\nworse... the folks who believe that by buying \"uncured\" bacon (at a health food or organic food store) are being misled. since the USDA consider curing to be something done with *added* nitrites, what the \"uncured\" bacon manufacturer does is adds celery powder to the flavorings. why? well, only because celery contains such high levels of nitrite, that a small amount of celery powder will cure the bacon in the same exact way, chemically, as it would have been had they simply used nitrite by itself. a loophole. and for all intents and purposes, the same exact product as \"regular\" bacon, with all the same health risks.\n\nmore [HERE](_URL_0_)\n\nEDIT: added links",
"Nitrites and nitrates aren't bad by themselves; in fact they can be beneficial as some others have pointed out. \nThe real problem is that nitrites and nitrates can react with protein to make nitrosamines which are carcinogenic. This reaction takes place to a small degree in your stomach acid but mainly at high temperatures, for example when cooking bacon.",
"When I eat a bunch of foods associated w / nitrates nitrites (hotdogs or especially a bunch of bacon)... my pee smells funny.",
"My neurologist told me that nitrites and nitrates can aggravate my migraines. I'm not sure of the science behind this, but thought I would add that. The book he gave me that suggested avoiding this \"trigger\" was called \"Heal Your Headache\". \n\nI try to get lunch meat and bacon without nitrites and nitrates for this reason, but haven't honestly noticed a difference in my occurrence of migraines. However, everyone has different thresholds for different triggers. ",
"So don't eat. Got it. All that food is all bullshit anyways is the message I'm getting here."
]
} | [] | [] | [
[],
[
"https://en.wikipedia.org/wiki/Nitrosamine#Cancer",
"http://www.ncbi.nlm.nih.gov/pubmed/9681972"
],
[
"http://chriskresser.com/the-nitrate-and-nitrite-myth-another-reason-not-to-fear-bacon/",
"http://www.pronutritionist.net/2010/08/nitrates-are-beneficial-where-did-i-get-it-wrong/",
"http://junkfoodscience.blogspot.com/2008/07/does-banning-hotdogs-and-bacon-make.html"
],
[],
[],
[],
[]
] |
||
iu54p | What is/are the common human observable phenomenon that science has not been able to explain? | For e.g.
How/why bikes stay upright while driving?
What is gravity (we know what it does but what it actually is?)
..
.. | askscience | http://www.reddit.com/r/askscience/comments/iu54p/what_isare_the_common_human_observable_phenomenon/ | {
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"text": [
"I don't know if I'd say that bicycling is an unanswered question. We know a lot about gravity but maybe you're referring to unified theory/graviton stuff. \n\nBut two things that come to my mind immediately are [thunder](_URL_0_) and [yawns](_URL_1_).",
"deja vu?\n\nHiccups?\n",
"Just so you know, \"For e.g.\" is a tautology: e.g. means \"for the sake of example\" so you don't need the \"for\" before it.\n\nAlso, gravity is just geometry, specifically, a consequence the curvature of spacetime.",
"How cats purr.",
"Tide goes in, tide goes out.\n\nNever a miscommunication.\n\nYou can't explain that."
]
} | [] | [] | [
[
"http://en.wikipedia.org/wiki/Thunder",
"http://en.wikipedia.org/wiki/Yawn"
],
[],
[],
[],
[]
] |
|
5iao8a | why is there such a push to limit lobbying in government, but not a push to hold the government accoutable for the ills that ensue? | EDIT: I understand elections deal with this, but as long as were talking about passing laws limiting the power of lobbyists, why wouldn't we also pass laws to remove politicians that are representing industries or companies more so than individuals? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/5iao8a/eli5_why_is_there_such_a_push_to_limit_lobbying/ | {
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"text": [
"I assume you mean ills and boons? Just accountable?\n\nIn that vein, I've felt for a long time that when appropriate, laws should be written more like scientific grants. As in, \"we are enacting this law for this purpose, and if successful, we will see these changes to these indices after this amount of time.\" Then (also like science), we can debate the correct indices and the correct amount of time given the money, but there won't be an endless debate about whether the law accomplished its goals. "
]
} | [] | [] | [
[]
] |
|
prnvq | Is there any verifiable evidence that pit bulls are more aggressive than other dog breeds (mental, etc), or has misrepresentation in the media formed this belief? | I've always heard that pit bulls are aggressive. They seem to be the most discussed dog breed in the news. Is there any basis for this? I've read that in the '70s, there were a revered breed, much like the Golden Retriever and the Labrador Retriever are today.
I'd just like to know if there is any evidence to support this. | askscience | http://www.reddit.com/r/askscience/comments/prnvq/is_there_any_verifiable_evidence_that_pit_bulls/ | {
"a_id": [
"c3roxt2"
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"text": [
"To my knowledge there isn't any evidence to suggest that they are more aggressive when you control for environment. I just did a search of the medical literature and didn't find any thorough study of aggressiveness in any dog breed. \n\nThe general consensus among experts seems to be its pitbulls are so bad, but rather pitbull owners. Here is an article in the Canine Veterinary Journal that argues this point: _URL_0_\n\nIt is pointed out in [this](_URL_1_) Malcolm Gladwell article, and pointed out by you, that \"rotten dog breed\" seems to shift about every decade or so. Some of the breeds that we consider extremely gentle such as Golden or Labarador retrievers, bulldogs, and German shephards were once considered extremely dangerous.\n\nThe last point that I think is worth mentioning is that the argument against pitbulls isn't solely that they are aggressive, but also that when they *are* aggressive that they have strength and power to do a lot of damage. This part is true, more or less, but still doesn't justify some of the tough laws and opinions on pitbulls. "
]
} | [] | [] | [
[
"http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1476525/?page=2",
"http://www.gladwell.com/2006/2006_02_06_a_pitbull.html"
]
] |
|
njzf3 | What is the physical mechanism that causes multi-pendulum behavior? | _URL_0_
What describes this type of motion? And why can it not be used in energy generation? | askscience | http://www.reddit.com/r/askscience/comments/njzf3/what_is_the_physical_mechanism_that_causes/ | {
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"c39ov0t",
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"text": [
"The behavior is chaotic. This is the most famous chaotic system. The behavior cannot be described in a formal way, because it is impossible to predict what it will do in the future (small pertebations will make it take a different path ).\n\nHow would you use it for energy generation? The only reason this keeps spinning for a long time is that it is well oiled. It is not a perpetual motion machine.",
"The behavior is chaotic. This is the most famous chaotic system. The behavior cannot be described in a formal way, because it is impossible to predict what it will do in the future (small pertebations will make it take a different path ).\n\nHow would you use it for energy generation? The only reason this keeps spinning for a long time is that it is well oiled. It is not a perpetual motion machine."
]
} | [] | [
"http://www.youtube.com/watch?feature=player_embedded&v=vjVQWG7xUQk"
] | [
[],
[]
] |
|
3jif7n | Why was California the bread basket of America even though it's very short on water supply? | AskHistorians | https://www.reddit.com/r/AskHistorians/comments/3jif7n/why_was_california_the_bread_basket_of_america/ | {
"a_id": [
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"text": [
"California has a perfectly good supply of water. Usage simply far outstrips that supply, much as it does in the central plains. There's quite a few reasons behind the large agricultural industry there though. The first and biggest reason is that Central Valley is simply the largest area of high grade soil anywhere on earth and the neighboring regions are extraordinarily fertile land as well. Secondly, California is largely oriented north to south and the state has three very different seasonal cycles in the north, center, and south. The north gets quite a bit of rain, but is more mountainous and less suitable for large megafarms in most areas. The center has several major rivers and valets that are dammed to collect the moderate rainfall and stays relatively temperate year round. However, when the north and center can't grow summer crops in winter, the south is warm enough that it can. Over 90% of winter greens come from imperial and Yuma counties. The combination of incredible and abundant farmland with year round agriculture and an enormous industrial base means that California's enormous water resources are completely inadequate. ",
"Is California really the 'breadbasket of America'? Admittedly, the state grow huge amounts of vegetables and nuts. However, far more grain is grown in the midwest/plains. California only produces significant amounts of rice, but compared to these other states its grain production is very small."
]
} | [] | [] | [
[],
[]
] |
||
8mklnv | what causes a rue to thicken a sauce once it starts boiling? | explainlikeimfive | https://www.reddit.com/r/explainlikeimfive/comments/8mklnv/eli5_what_causes_a_rue_to_thicken_a_sauce_once_it/ | {
"a_id": [
"dzobdep",
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"text": [
"Starch (such as the flour in roux) absorbs water and swells up when heated. Normally, these swollen starches would clump together, which is why you coat the individual starch granules in fat first by making a roux.",
"Wheat flour can absorb many times it's own weight in water. Hotter water is more readily absorbed than colder water. Roux is flour and butter and when heated the butter adds flavor, and the flour begins absorbing moisture from the food, causing the flakes of flour to swell with water. The result is a thickening of the food. \n\nThis is the basis for many thick liquids like puddings, gravies, and base sauces used in cuisine. "
]
} | [] | [] | [
[],
[]
] |
||
2e0prc | what does it mean when something that happens in a tv series or a movie is considered "canon" while certain other mediums are not (books or comics)? | For example, why are TV episodes of the Simpsons are considered canon but the comic book series are not. | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/2e0prc/eli5_what_does_it_mean_when_something_that/ | {
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"text": [
"Canon means it is part of the official storyline and is approved by the author, or a group the author has put in charge.\n\nFor example ... Star Wars books had to be sent into Lucas Arts and be approved by George Lucas' team. They would read over it, edit stuff that was wrong, and send it back to the author to be corrected. ",
"Basically it means that it actually happened in the shows universe. A lot of times spin offs, while they may use the same characters, are not considered canon. The death of a character in the comic may not be meant to die in the show, therefore, that death is not canon to the show.",
"Another way this happens is with video games with multiple endings. There's one that's canon, meaning it is officially the ending. The rest are just for fun, or so you don't feel so bad about a character dying or something.",
"A lot of times, when you have a series that gets licensed out a lot, conflicting information will come up, so canon is what's official, non-canon is what's not.\n\nOne example I can think of, in the Street Fighter video games, the canon is that Charlie is killed by M. Bison, and that Blanka became a monster because he spent his life in the jungle being raised by animals. However, in the Street Fighter movie, which is non-canon, M. Bison captures Charlie and experiments on him, turning him into the monster that is Blanka."
]
} | [] | [] | [
[],
[],
[],
[]
] |
|
1d1yq3 | what's with this ameristralia thing? | explainlikeimfive | http://www.reddit.com/r/explainlikeimfive/comments/1d1yq3/eli5_whats_with_this_ameristralia_thing/ | {
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"text": [
"I am also confused. ",
"There was a post describing how Aussies have fought with us in every war since ww2, then things escalated quickly",
"It started as a joke about Aussies getting on as US redditors were going to beef (a shift change type thing.) Other nationalities got upset by this limited dichotomy, so in response, the US and Aussie redditors united to assert their ongoing dominance. "
]
} | [] | [] | [
[],
[],
[]
] |
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