question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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This may be a stupid question, are stars the only source of sun in the known universe? | Stars are not the only sources of light in the universe. Light is produced by any object with nonzero temperature; the color of the light is dependent upon the temperature. This is called [blackbody radiation](_URL_1_) (and it's the reason that IR cameras produce images that look like [this](_URL_0_).) Even if stars as... | [
"The scientists are unprepared, however, for the stars. Because of the perpetual daylight on Lagash, its inhabitants are unaware of the existence of stars apart from their own; astronomers believe that the entire universe is no more than a few light years in diameter and may hypothetically contain a small number of... |
why are nationalsocialists seen as right wing and not as left wing? | because the 'right/left' divide is a hopeless oversimplification of a complex multivariate set of issues. | [
"Right-wing populism, a political ideology that often combines \"laissez-faire\" capitalism, nationalism, ethnocentrism and anti-elitism, is sometimes described as far-right. Right-wing populism often involves appeals to the \"common man\" and opposition to immigration. Far-right politics sometimes involves anti-im... |
Did medieval Middle-Eastern monarchs have crowns, crown jewels, and coronations? What were the Middle Eastern symbols of royal power, and how were their reigns formalized? | The Middle Ages are a broad and ill-defined period, and the Middle East is similarly broad and ill-defined in a geographic sense. So I'll take these questions one at a time, and try to treat the various cultures of medieval Islam.
*Did medieval Middle-Eastern monarchs have crowns?*
It's complicated. The most common A... | [
"Use of regalia by monarchs in England can be traced back to when it was converted to Christianity in the Middle Ages. A permanent set of coronation regalia, once belonging to Edward the Confessor, was established after he was made a saint in the 12th century. They were holy relics kept at Westminster Abbey – venue... |
why do ceasefires not take place immediately? | In a war zone, it takes time to get the message out to everybody. Communications in combat, almost by definition, can be difficult. You don't want a ceasefire to fail just because one or two small units didn't get the message in time. A delay gives both parties plenty of time for the message to get out and to allow bot... | [
"A ceasefire (or truce), also called cease fire, is a temporary stoppage of a war in which each side agrees with the other to suspend aggressive actions. Ceasefires may be declared as part of a formal treaty, but they have also been called as part of an informal understanding between opposing forces. A ceasefire is... |
how does cold water wake you up? | Splashing your face with very cold water (or even better plunging your face into a sink full of water) makes your brain think "shit, I've just dived into some water!". It then kicks in a load of reactions including releasing alertness chemicals into your brain and increasing blood flow to important organs and your bra... | [
"Cold water dousing is used to \"shock\" the body into a kind of fever. The body's reaction is similar to the mammalian diving reflex or possibly temperature biofeedback. Several meditative and awareness techniques seem to share similar effects with elevated temperature, such as Tummo. Compare cold water dousing wi... |
Are all molecules on Earth the same age? | No. Atoms are not the same age either.
I'm sure there are new theories out now, but I believe only energy has existed with time identically.
Atoms can be made in stars. Hydrogen crushed in to helium, so on and so on.
Then atoms can form molecules.
The energy is used to make all this matter.
On earth the bulk of ... | [
"Because the age of the Earth is (4.6 billion years), the half-life of the given nuclides must be greater than about (100 million years) for practical considerations. For example, for a nuclide with half-life (60 million years), this means 77 half-lives have elapsed, meaning that for each mole () of that nuclide be... |
how do products like beano alleviate gas? | They contain digestive enzymes that allow you to break down the components of food into smaller things (the class of "Lipase" enzymes breaks down fats from lipids, for example) that your body can more easily process. You take these products about 30 minutes before a meal to allow your system to process foods more effe... | [
"Beano is an enzyme-based dietary supplement that is used to reduce gas in the digestive tract, thereby improving digestion and reducing bloating, discomfort, and flatulence caused by gas. It contains the enzymes alpha-galactosidase (α-GAL) and invertase. It was introduced as a liquid, but that has been discontinue... |
why can i drink 12 beers and not feel full, but when i drink 2 bottles of water i am bloated?!?!? | Alcohol triggers a receptor in your brain called a GABA receptor. GABA is an inhibitory neurotransmitter. Basically when you are drunk your brain works more slowly. Part of that working more slowly makes it harder to concentrate, harder to speak, slower reaction time, and less sensation of pain. That sensation of p... | [
"When the water bottle is full, it overturns. When the piggy bank remains empty, it is whole. Therefore, the gentleman: Resides in vacuity rather than existence, and exists in the lacking rather than the complete. (Wilson 1985) \n",
"If left for longer in bottles, the secondary fermentation will increase the alco... |
I've heard that during the First and Second World Wars many soldiers would deliberately miss their shots when shooting at enemy soldiers. Is there any truth to this? Did it vary from army to army, or war to war? | There has been a lot of discussion about this, mostly inspired by Dave Grossman's *On Killing: The Psychological Cost of Learning to Kill in war and Society* and a number of other books such as Melanie Joy's *Unnatural Born Killers*.
Opinion on the validity of these claims is divided to say the least and hence there i... | [
"The popular image of a World War I combat is of a wave of soldiers with bayonets fixed, \"going over the top\" and charging across no man's land into a hail of enemy fire. Although this was the standard method of fighting early in the war, it was rarely successful. British casualties on the first day of the Battle... |
why hasn't china started phasing out symbolic writing and started standardizing phonetic (pinyin 拼音) writing? | Part of it is that while there is a unified Chinese *written* language, there are dozens (maybe hundreds, I don't know for sure) of difference *spoken* Chinese languages (i.e. dialects). Pinyin corresponds to Mandarin Chinese (the official spoken language) while there are many other dialects (Cantonese, Shanghainese, F... | [
"The most productive method of Chinese writing, the radical-phonetic, was made possible by ignoring certain distinctions in the phonetic system of syllables. In Old Chinese, post-final ending consonants and were typically ignored; these developed into tones in Middle Chinese, which were likewise ignored when new ch... |
Could you replace bones with a metal, or any substance harder than bone? | I'm speaking from the experience of having worked in the bone tissue engineering field, not a doctor, but it's common practice to replace part of your bone with other materials. For instance, artificial hips are replacements to bone. Generally, these replacements are drilled deep into the bone and treated or speciali... | [
"Research on artificial bone materials has revealed that bioactive and resorbable silicate glasses (bioglass), glass-ceramics, and calcium phosphates exhibit mechanical properties that similar to human bone. Similar mechanical property does not assure biocompatibility. The body's biological response to those materi... |
Why do some fruits have multiple seeds while others have just 1? | Different species have different reproductive strategies. They each have their pros and cons. Smaller seeds are easily swallowed and they spread because animals eat them. In that case it's a numbers game because not all the seeds will make it through the digestive system. Larger seeds can thrive in more stressful envir... | [
"Multiple fruits are the fruits of two or more multiple flowers that are merged or packed closely together. The mulberry is a berry-like example of a multiple fruit; it develops from a cluster of tiny separate flowers that become compressed as they develop into fruit.\n",
"Seedless fruits can develop in one of tw... |
To What Degree Was Metal Commonly Used in Shields? | I don't believe fully metal shields came into being before the rotella, which were used mainly by the Spanish before they fully developed the tercio pike & shot formations. They only lasted for about 50-60 years before being made obselete.
I guess you could count bucklers as shields though but to what extent they w... | [
"The oldest form of shield was a protection device designed to block attacks by hand weapons, such as swords, axes and maces, or ranged weapons like sling-stones and arrows. Shields have varied greatly in construction over time and place. Sometimes shields were made of metal, but wood or animal hide construction wa... |
how are wooden bows so flexible without breaking while the same type of wood used to make a table (for example) would break if you flexed it that far? | I don’t know if they make tables out of yew, but the geometry makes a difference. A table is a slab designed not to bend, but to hold up a load. A bow is tapered towards the ends so the flex is distributed in a way the wood can support. Many bows are laminated to increase this ability. | [
"Any wooden bow must have gentle treatment and be protected from excessive damp or dryness. Wooden bows may shoot as well as fiberglass, but they are more easily dented or broken by abuse. Bows made of modern materials can be left strung for longer than wood bows, which may take a large amount of set if not unstrun... |
How did the Russian Army perform so well against the Allies during the Crimean War despite their logistical and technological disadvantages? | A couple of points:
* A lot of the Crimean campaign boiled down to a siege against Sebastopol. This tended to level the playing field for the Russians. A siege takes fewer people to defend, the defenses give an advantage against an attacker's firepower and so on.
* The allied armies in the Crimea won pretty well ever... | [
"The military of the Russian Empire consisted of the Imperial Russian Army and the Imperial Russian Navy. The poor performance during the Crimean War, 1853–56, caused great soul-searching and proposals for reform. However the Russian forces fell further behind the technology, training and organization of the German... |
how does bbc series planet earth have such amazing videography? | Planning. And a lot of waiting.
The whole thing took 5 years to film. I imagine there was some overlapping of projects there too.
| [
"Planet Earth is a 2006 British television series produced by the BBC Natural History Unit. Five years in the making, it was the most expensive nature documentary series ever commissioned by the BBC and also the first to be filmed in high definition. The series received multiple awards, including four Emmy Awards, ... |
How Foxes Use Earth's Magnetic Field To Hunt Prey on snow? | Foxes have a hunting behaviour called 'mousing' where they approach a prey animal that is hidden under snow or vegetation cover, and when they're a couple of feet or so away they jump high in the air to attack the prey animal from above. A bunch of researchers found that when the foxes perform this mousing leap after a... | [
"A 2008–2010 study of 84 red foxes in the Czech Republic and Germany found that successful hunting in long vegetation or under snow appeared to involve an alignment of the fox with the Earth's magnetic field.\n",
"Corsac foxes are nocturnal and nomadic hunters of the steppes. They do not have a defended territory... |
why can hospitals refuse to give lifesaving treatments? | This isn't always about money. Sometimes this is about quality of life. It's a really hard conversation to have, but it's true - sometimes, even when the patient and the family want everything to be done for them, an intervention as traumatic as CPR isn't in the best interests of *anyone* involved.
However, sometimes... | [
"Where for-profit hospitals in such countries admit uninsured patients in emergency situations (such as during and after Hurricane Katrina in the USA), they incur direct financial losses, ensuring that there is a clear disincentive to admit such patients. In the United States, laws exist to ensure patients receive ... |
Why do our muscles become bigger after tearing? | This is covered in great detail in this review from 2004
"Cellular and molecular regulation of muscle regeneration."
_URL_0_
Which is summarised nicely here:
_URL_1_ | [
"Ripping is the stage that people, mainly bodybuilders, go through in order to lose body fat to a very low percentage. The idea is that if one's body fat is low, then muscle tissue will be more visible and therefore a better-looking body will emerge.\n",
"As granulation tissue matures, the fibroblasts produce les... |
Did Helen of Troy have a daughter named Hermione? | Helen is not a historical figure, nor is the *Iliad* a historical text, and this question is better suited to, say, /r/Classics. But since there is no shortage of classicists around here:
Hermione is not mentioned in the *Iliad*, but she features in the *Odyssey*. At *Odyssey* 4.12 Hermione is said to be the daughter ... | [
"Agamemnon married Clytemnestra, and Menelaus married Helen, her famously attractive sister. Helen later left Sparta with Paris of Troy, and Menelaus called on all of his wife's former suitors to help him take her back.\n",
"Clytemnestra (; , \"Klytaimnḗstra\", ), in Greek mythology, was the wife of Agamemnon, ki... |
what do retailers gain from using promo codes and coupons? | Increased number of sales. Purchases made at a reduced profit margin are still more valuable than purchaes that are never made at all. | [
"Online retailers often refer to coupons as \"coupon codes\", \"promotional codes\", \"promotion codes\", \"discount codes\", \"keycodes\", \"promo codes\", \"surplus codes\", \"portable codes\", \"shopping codes\", \"voucher codes\", \"reward codes\", \"discount vouchers\", \"referral codes\" or \"source codes\". ... |
what is the objective reality? | Objective reality is the unverifiable *what is really out there* - outside of us, unprocessed by our senses and our minds. Philosophers have been taking cracks at it throughout history. The closest we've probably gotten to it is the creation of the Scientific Method, which unlike religion or philosophy is rigidly struc... | [
"Certain ideas from physics, philosophy, sociology, literary criticism, and other fields shape various theories of reality. One such belief is that there simply and literally \"is\" no reality beyond the perceptions or beliefs we each have about reality. Such attitudes are summarized in the popular statement, \"Per... |
when i've got bluetooth turned on, how can my phone be visible to paired devices but invisible to every other device? | You have to actually tell your phone to advertise itself to other bluetooth devices. Basically, you tell it to go "HEY GUYS!!! I'M RIGHT HERE!!!"
When you tell another device to scan for bluetooth devices, it looks for anything that's advertising itself.
That's different from it connecting *directly* to a device it ... | [
"Bluetooth beacons use Bluetooth low energy proximity sensing to transmit a universally unique identifier picked up by a compatible app or operating system. The identifier and several bytes sent with it can be used to determine the device's physical location, track customers, or trigger a location-based action on t... |
why does reddit only let me post one comment every ten minutes. and why can i not post on certain subreddits at all? | it's b/c your account is new. it's to prevent spammers. just be patient get some upvotes and this restriction will go away. | [
"One common faux pas on Internet forums is to post the same message twice. Users sometimes post versions of a message that are only slightly different, especially in forums where they are not allowed to edit their earlier posts. Multiple posting instead of editing prior posts can artificially inflate a user's post ... |
what is the relationship between the nsa and cia? | Huh? The CIA generally deals in human intel, intel collection, assets, clandestine ops, etc. The NSA deals with electronic surveillance, encryption, and code breaking. They have two different purposes. And yes they work together not against each other. That's like saying the Army is spying on the Navy, they may not a... | [
"Unlike the CIA and the Defense Intelligence Agency (DIA), both of which specialize primarily in foreign human espionage, the NSA does not publicly conduct human-source intelligence gathering. The NSA is entrusted with providing assistance to, and the coordination of, SIGINT elements for other government organizati... |
how long does the water cycle take? how long would it take one drop of rainwater to make it through and fall as rain again? | It can be as fast as one day, or as long as many thousands of years (if the raindrop ends up in a glacier or in an underground aquifer). | [
"Depending on the time of year, the river tide rises and falls twice a day by up to 7 m (24 ft) and, due to the need to overcome the outflow of fresh water from the Thames Basin, it takes longer to subside (6–9 hours) than it does to flow in (4–5 hours).\n",
"The average flow rate is 311 liters per second, but in... |
Just how far can signals from Earth go? | There is no fundamental limit. You just need larger receivers and more time for larger distances.
The Arecibo telescope could reasonably send text messages and even some images to equivalent telescopes on planets orbiting nearby stars, with decreasing transmission rate for larger distances. Make sender and receiver la... | [
"A two-way distance record for communication was set by the Mercury laser altimeter instrument aboard the MESSENGER spacecraft, and was able to communicate across a distance of 24 million km (15 million miles), as the craft neared Earth on a fly-by in May, 2005. The previous record had been set with a one-way detec... |
Were decapitations common on medieval battlefields? | Short answer: No. It's a tricky shot, and the neck is actually fairly easy to armor with either a gorget or a mail aventail off the helmet.
Long answer: The best record I know of for wounds in a medieval battle is the [Battle of Visby](_URL_1_), which took place in 1361. The battle was extremely one sided, with a gr... | [
"Since 1371 or earlier murderers and rapists have been executed by decapitation on the medieval stone bridge. The most recent recorded execution took place in 1585. Till 1799 the bridge was decorated with the statues of two figures, recalling an oft-repeated legend.\n",
"Dieter Furcht speculates that the impaleme... |
why do bikers bike on the road when there is a sidewalk right next to them? | In many places it is illegal to bicycle on the sidewalk. So if you want to ride legally and there's no bike path, you ride on the road. | [
"Cyclists may travel either in the street or on the sidewalk. On the sidewalk they must behave so as not to cause danger to pedestrians (which is an arbitrary judgment that seems to translate into traveling at walking pace). Moreover, in some of the cities within the greater Los Angeles region, it is illegal to cyc... |
how are some flying animals (e.g - sparrows and house flies) able to fly at such a high speed without bumping into anything? | The brains of flying animals are specifically evolved to handle the calculations and processes needed for flight. Humans bump into things when they move at ridiculous speeds because we evolved to move at medium and low speeds, dedicating more of our brainspace to things like language. When your entire brain is fly, eat... | [
"BULLET::::- Slowest. Most flying animals need to travel forward to stay aloft. However, some creatures can stay in the same spot, known as hovering, either by rapidly flapping the wings, as do hummingbirds, hoverflies, dragonflies, and some others, or carefully using thermals, as do some birds of prey. The slowest... |
if there are so many women saying bill cosby raped them, why isn't any trial or any legal issues going on? seems like it's all just people saying things, and nobody taking it serious. like "there's another accuser." if so many women are reporting this, why isn't he being questioned under oath? | Most of the accusations are for things that happened quite a long time ago. There's probably no concrete evidence left, and many cases may even be past the statute of limitations. In either case, it's very hard to get a conviction off "he said, she said". | [
"BULLET::::- Bill Cosby - Castor declined to prosecute Cosby for sexual assault in 2005 after he found \"insufficient, credible and admissible evidence exists upon which any charge against Mr. Cosby could be sustained beyond a reasonable doubt.\" In November, 2014 and through the November 2015 election, Castor's de... |
how does the world keep track of all of its digital money? | It is a tangled mess, I will try to simplify. Trying to eli5, probably failing.
Let's start simple. Your bank account. Your bank account is money that the bank is holding onto for you. The bank has a major incentive to think the number is correct.
They have several safeguards in place. Including multiple redundant s... | [
"Since modern computers can store and process information and data in virtually any format and with the Internet allowing easy transfer of this data, the number of scenarios in which submissions can be collected electronically has increased exponentially in the last few years. Some of these scenarios are described ... |
This might be a dumb question, but if Homo Sapien Sapiens could interbreed with Neanderthals how are their descendants called Homo Sapien Sapiens? Aren't they another species all together? | Simply put, because the amount of interbreeding was small and uneven. Some people have neanderthal DNA, others don't, they are clearly the same species as each other. | [
"\"Homo sapiens neanderthalensis\" was proposed by King (1864) as an alternative to \"Homo neanderthalensis\". There have been \"taxonomic wars\" over whether Neanderthals were a separate species since their discovery in the 1860s. Pääbo (2014) frames this as a debate that is unresolvable in principle, \"since ther... |
do i perceive my own body differently than others? | Yes. Self-consciousness is a real double-edged sword. It allows us to think abstractly but it also forces us to imagine ourselves through others' lenses. The average person (Westerner?) criticizes their appearance regularly. | [
"The human capacity to recognize the bodily feelings of another is related to one's imitative capacities, and seems to be grounded in an innate capacity to associate the bodily movements and facial expressions one sees in another with the proprioceptive feelings of producing those corresponding movements or express... |
Another Question Out of the Show Curiosity: The Relationship Between Quantum Mechanics and the Laws of Thermodynamics | It is important to know that the laws of thermodynamics are based on statistics. Thermodynamic laws don't say what will happen to a single atom, only to a large collection of atoms.
For example, if you have two chambers separated by a movable wall and you pump up one half of the chamber to 1000 psi and leave the othe... | [
"Quantum thermodynamics is the study of the relations between two independent physical theories: thermodynamics and quantum mechanics. The two independent theories address the physical phenomena of light and matter.\n",
"Quantum versions of stochastic thermodynamics have been studied for some time and the past fe... |
How did the world leaders and people of the day actually react to George Washington's relinquishing of power and refusal to crown himself a king? | Here's one of the more famous anecdotes quoted here from *George Washington: The Founding Father (Eminent Lives)* by Paul Johnson:
> Everyone else, in varying degrees, was astonished at this singular failure of the corruption of power to work. And, indeed, it was a rare moment in history. In London, George III quest... | [
"George Washington's resignation as commander-in-chief marked the end of Washington's military service in the American Revolutionary War and his return to civilian life at Mount Vernon. His voluntary action has been described as \"one of the nation's great acts of statesmanship\" and helped establish the precedent ... |
Will mosquito bites heal faster if they are not scratched? | The more you scratch, the more inflamed and irritated the area will become. Bite or no bite, it is an open injury and will heal as such.
Baking soda mixed with water will help lessen the itchiness. And rub it *on* the bite, don't drink it. | [
"The saliva of the mosquito transmitted to the host with the bite can cause itching and a rash. In addition, many species of mosquitoes inject or ingest (or both) disease-causing organisms with the bite and are thus vectors of diseases such as malaria, yellow fever, Chikungunya, West Nile virus, dengue fever, filar... |
Could Ming Dynasty China have really been capable of reaching the Americas? | There's always room for discussion, but perhaps the sections [Historians' views of Gavin Menzies' "1421: The Year China Discovered the World"](_URL_0_) and [Travel and contact across the Atlantic before Columbus](_URL_1_) from our FAQ will answer your inquiry. | [
"The Yuan dynasty and expanding Sino-Arab trade during the 14th century had gradually expanded Chinese knowledge of the world: \"universal\" maps previously only displaying China and its surrounding seas began to expand further and further into the southwest with much more accurate depictions of the extent of Arabi... |
why does cling film sometimes stick to the plate, bowl etc. and other times don't? | Static electricity. That's the cling in cling wrap. Remove all the electrons from it and it looses that magic. Learned this from Mr. Wizard. The OG science guy. | [
"The expansion of trapped moisture can result in internal separation (delamination) of the plastic from the die or lead-frame, wire bond damage, die damage, and internal cracks. Most of this damage is not visible on the component surface. In extreme cases, cracks will extend to the component surface. In the most se... |
Given that Pre-Islamic Arabia was a very women-friendly and sexually "liberal" society, what is the source of Islam's extremely puritanical culture? | Hey!
So this has a couple of different parts that I hope to address. I can't give a super specific answer, but will try to touch on a number of facets you could ask follow-up questions about. I'm pulling some from previous answers that I have written, but much of this is also new. A great book on this topic is Leil... | [
"Feminist critics of the notion that Islam significantly bettered the status of women include Leila Ahmed, who states that Islamic records show that at least some women in pre-Islamic Arabia inherited wealth, ran businesses, chose their own husbands, and worked in respected professions. Fatima Mernissi similarly ar... |
- how do knives work | The strength of objects is usually measured best with what's known as *pressure*. That is, an object can take a certain amount of pressure before breaking. Human strength is instead measured by *force*; you can exert a certain amount of force by swinging your arm.
Now, how are these two things related? Well, pressure... | [
"The handle, used to grip and manipulate the blade safely, may include a \"tang\", a portion of the blade that extends into the handle. Knives are made with partial tangs (extending part way into the handle, known as \"stick tangs\") or full tangs (extending the full length of the handle, often visible on top and b... |
Why did liberal democracies flourish in North America and Europe earlier than in other continents? | Western Kings tended to be very weak compared to eastern kings( the power of the Chinese emperor for instance was leagues ahead of the European competition). At the same time you had a long history of councils such as Parliament, Estates General, Hungarian Diet etc.. who often formed the basis for Democratic movements.... | [
"Outside Europe another group of republics was created as the Napoleonic Wars allowed the states of Latin America to gain their independence. Liberal ideology had only a limited impact on these new republics. The main impetus was the local European descended Creole population in conflict with the Peninsulares—gover... |
how is a person's muslim faith verified before entering mecca? | If you mean the Hajj pilgrimage, there's a specific Saudi visa you need to get. Male Hajj pilgrims (mahram) apply for it (women can't apply for their own and must be accompanied by a mahram).
If you're a convert, you must supply an Islamic Certificate from your local Islam Centre. | [
"Jerusalem is Islam's third holiest city after Mecca and Medina in Saudi Arabia. Although the Koran does not clarify from where exactly Muhammad ascended to Heaven, the \"Haram al Sharif\" (Temple Mount) of Jerusalem is believed by Muslims to be the location. According to the tradition, during a single night around... |
What would change in the next ten years in your field of science if tomorrow computing power increased ten thousand fold? | I'd finally be able to run Crysis. But seriously, better weather simulations. | [
"Technological change is a combination of more and of better technology. A 2011 study in the journal \"Science\" showed that the peak of the rate of change of the world's capacity to compute information was in 1998, when the world's technological capacity to compute information on general-purpose computers grew at ... |
How is it that figure skaters can spin a hundred or so times during a performance and skate just fine, and yet I get dizzy after spinning my child ten or so times? | It turns out that [yes](_URL_1_) you can train yourself to get less dizzy. [Here's](_URL_0_) a much more readable summary of that paper by the way. In short, it says that over years of practice, ballet dancers can train their brain to be less susceptible to dizziness. In this case I think it's fair to assume that a ... | [
"Roller skating also traditionally emphasizes spins that are uncommon on ice, especially the \"inverted camel\" in which the skater is on an outside edge standing on the right foot with their body and left leg extended outward parallel to the floor, the skater then rotates their hips 180 degrees while continuing to... |
Can you make a nuclear bomb with any element? | No. There are a few basic requirements that a nuclear warhead should meet in order to be useful. First, you need nuclear reactions that release energy, and as much of it as possible. Second, you need this reaction to be as easy as possible to initiate; you don’t want a large energy barrier to overcome. In broad strokes... | [
"Only Germany, the US and Russia may research the atomic bomb, and this takes several stages, including controlled reaction and either plutonium production or uranium separation. Success creates a bomb 2-6 turns later, and another every 2 turns thereafter. An atomic bomb may be delivered by bomber, or by rocket or ... |
does two shirts help handle the heat? | Air is actually a decent insulator, and trapping air is actually how many types of insulation work. So a layer or more of air can reduce the transfer of heat from the environment to your body.
Of course your body is also producing heat which it needs to get out, so you can't just pack yourself in insulation. But if t... | [
"Most heated clothing is designed for cold-weather sports and activities, such as motorcycle riding, downhill skiing, diving, winter biking, and snowmobiling, trekking and for outdoor workers such as construction workers and carpenters. Since the London Olympics, heated clothing has also been used by athletes to ke... |
why aren't the people who own the pictures we use as memes sue the hell out of the websites and users that use them? | The 'Techno Viking' is doing exactly that. Someone did make a lot of money from that famous video, and he wants his cut. | [
"Many people upload their photographs to social networking websites and other websites, in order to share them with a particular group or with the general public. Those interested in legal precision may explicitly release them to the public domain or under a free content license. Some sites, including Wikimedia Com... |
why is it that no matter how many times i mix up my sour cream, the next time i use it there always is liquid at the top? | Because it separates out slowly between uses. It isn't a completely stable mixture, it is like sediment in water slowly settling as it is left calm. | [
"In the wine/water mixing problem, one starts with two barrels, one holding wine and the other an equal volume of water. A cup of wine is taken from the wine barrel and added to the water. A cup of the wine/water mixture is then returned to the wine barrel, so that the volumes in the barrels are again equal. The qu... |
how do random picks work with computers and other machines? | The program reads a number which it assumes is random, the current time is a common example.
The program will then do math to this number to make it more unique. This means that even if the program reads the time twice in a very short period of time the second 'random' number won't be necessarily close to the first on... | [
"Although historically \"manual\" randomization techniques (such as shuffling cards, drawing pieces of paper from a bag, spinning a roulette wheel) were common, nowadays automated techniques are mostly used. As both selecting random samples and random permutations can be reduced to simply selecting random numbers, ... |
If a hybrid/battery-powered car is charged by a coal-based power plant, is it still greener than a purely gasoline-fueled car? | Thermal power plants and fossil-fueled automobiles are all powered with [heat engine](_URL_0_)s. Power plants typically use heat engines that resemble [Carnot heat engine](_URL_2_), whereas cars and trucks use [Otto](_URL_1_) and [Diesel](_URL_4_) heat engines. Under normal circumstances Carnot engine can achieve a muc... | [
"An electric car has a higher embodied energy than a combustion engine one, owing to the battery and electronics. According to Science & Vie, the embodied energy of batteries is so high that rechargeable hybrid cars constitute the most appropriate solution, with their batteries smaller than those of an all-electric... |
Were there any other kingdoms or empires with considerable power in Europe in High or Late Middle Ages apart from France, England and Holy Roman Empire? | The Byzantine Empire (or Eastern Roman Empire) was the powerful and ancient Eastern counterpart of the later German "Holy Roman Empire". But unlike the "German Kingdom", as the *Romaioi* called it, Byzantium was actually an unbroken extension of the old Roman Empire, unlike its Western imitator. When the HRE came about... | [
"From the High Middle Ages onwards, the Holy Roman Empire was marked by an uneasy coexistence with the princes of the local territories who were struggling to take power away from it. To a greater extent than in other medieval kingdoms such as France and England, the Emperors were unable to gain much control over t... |
why can't a hash function be reversed? | Hashing functions are made to process some data and produce unique data that is entirely dependent on the data. It is used for checking a file was downloaded correctly (a single differing byte will change the hash) so you can compare them.
Popular hashing functions (such as [SHA-1](_URL_0_) and [MD5](_URL_1_)) are des... | [
"Using a perfect hash function is best in situations where there is a frequently queried large set, , which is seldom updated. This is because any modification of the set may cause the hash function to no longer be perfect for the modified set. Solutions which update the hash function any time the set is modified a... |
If a bullet was shot vertically downward, would it still gain speed? | The bullet will continue to gain speed until the upward force due to air resistance completely cancels the downward force due to gravitational attraction - "terminal velocity".
**Edit:** As several people have pointed out, the bullet would actually slow to terminal velocity in this case. The physics, however remains... | [
"BULLET::::2. If the ball is moving much more rapidly than it was spinning, translational friction will dominate. The ball's angular velocity will be increased after impact, but its horizontal velocity will be decreased. The ball will not exceed its original height and will keep spinning in the same direction.\n",
... |
why does the sun get darker/more red as it sets? if it emits white light, then where do all the other colors go? | Firstly, the light emitted by the sun isn't pure white, it's on the yellow side of the spectrum.
When light passes through the atmosphere, it is diffracted and dispersed by the gases and particles contained within the atmosphere. This changes the quality of the light.
When the sun is directly overhead, the light is t... | [
"As the Sun crosses the sky, it may appear to be red, orange, yellow or white depending on its position. The changing color of the Sun over the course of the day is mainly a result of scattering of light and is not due to changes in black-body radiation. The blue color of the sky is caused by Rayleigh scattering of... |
Does ice reinforce something it has frozen over or does it make the object it has frozen easier to be broken? | I found [this link](_URL_0_) which basically says when an object becomes really cold, it becomes brittle. Usually in the movies, the thing that freezes them is really really cold like Liquid Nitrogen. Temperatures in the winter usually don't get cold enough to make thing brittle. | [
"The Resonance method of ice destruction means breaking sheet-ice which has formed over a body of water by causing the ice and water to oscillate up and down until the ice suffers sufficient mechanical fatigue to cause a fracture.\n",
"In the case of goods where preservation of structure is required, like food or... |
how does google maps and apple maps update their databases | There are third party GIS companies that collect data. They might buy data from a local government, or collect the data themselves. When data is not available they have to drive down each road to collect the data. Google has Street view cars that can fill this need, I don't know about Apple.
Overhead images come from ... | [
"Google Desktop includes plugins that allow indexing and searching the contents of local Microsoft Outlook, IBM Lotus Notes, and Mozilla Thunderbird email databases, outside of the client applications' built-in search functions. For Lotus Notes, only local databases are indexed for searching. Google Desktop's email... |
Is there a sense of cultural, social or historic loss in Germany due to the fact that massive portions of what was Prussia lie in modern day Poland, Russia (Kaliningrad Oblast) & Lithuania? | > "The Oder-Neisse, Eastern provinces - they're gone! They don't exist anymore"- Konrad Adenauer in conversation with Willy Brandt, 1953.
One of the curious features of Cold War-era maps produced in the FRG was that often listed the territories beyond the Oder-Neiße line as "under Polish/Soviet Administration." Th... | [
"The bulk of Prussia's losses were to Poland, including most of the provinces of Posen and West Prussia, and an eastern section of Silesia. Danzig was placed under the administration of the League of Nations as the Free City of Danzig. These losses separated East Prussia from the rest of the country, now only acces... |
How effective was the use of crystal meth by soldiers during the Blitzkrieg (in order to maintain speed and fight fatigue and low morale)? | More input is always welcome; in the meantime, you may be interested in what u/commiespaceinvader has to say on [this matter exactly](_URL_0_). | [
"Depleted uranium (DU) was widely used in tank kinetic energy penetrator and autocannon rounds for the first time ever during the Gulf War and has been suggested as a possible cause of Gulf War syndrome. A 2008 review by the U.S. Department of Veterans Affairs found no association between DU exposure and multisympt... |
What's going on in your ears when you change the pressure in your ears to listen to yourself hum? | By 'change the pressure' I'm going to assume you mean that you are opening your Eustachian tubes
_URL_0_
When these are open there is a direct link between the back of your nose/throat and your middle ear (behind the ear drum). | [
"Patients inside the chamber may notice discomfort inside their ears as a pressure difference develops between their middle ear and the chamber atmosphere. This can be relieved by ear clearing using the Valsalva maneuver or other techniques. Continued increase of pressure without equalising may cause ear drums to r... |
Prior to 1944, was Ukraine a part of Russia? | The name "Ukraine" has been used since the 16th-17th centuries if not earlier. During Soviet rule, most lands of the former Russian Empire were divided into "republics" (like states in the US but with borders based on locations of ethnic groups), and Ukraine was one such republic while Russia was another.
The western... | [
"Before World War II, the territory of modern Ukraine was divided primarily between the Ukrainian SSR of the Soviet Union and the Second Polish Republic. Smaller regions were part of Romania and Hungary. Only the Soviet Union recognised Ukrainian autonomy, and large numbers of Ukrainians, particularly from the East... |
tesla autopilot. | Clearing up a common misconception: "Autopilot" is *not* a self-driving car system. Tesla is *working* toward that goal, but not there yet.
The autopilot system is, at the moment, basically a clever combination of adaptive cruise control (follows the car in front of you's speed), automatic braking, lane assist, and da... | [
"In October 2014 Tesla Motors announced its first version of AutoPilot. Model S cars equipped with this system are capable of lane control with autonomous steering, braking and speed limit adjustment based on signals image recognition. The system also provide autonomous parking and is able to receive software updat... |
City Economic Policies from 40s-70s in America? | I can't answer specifically, but one of my mentors, Dr. Greg Hise, has written many books and articles about the growth and development of Los Angeles. He talks about the urban and economic development of the city in great detail.
Magnetic Los Angeles: Plannin the Twentieth-Century Metropolis by Greg Hise. | [
"The economic and cultural changes of the world in the 1960s have been attributed to these consumption changes. The antiauthoritarian protest movements of the young in the U.S., especially on college campuses, brought a new disdain for the \"standardization of look-alike suburbs,\" as well as fueled a movement towa... |
why did we ever think putting asbestos into buildings was a good idea? | It's one of if not the best naturally occurring fire retardant materials in the world. While also have very good insulating properties. Oh, and it's cheap and relatively easy to work with. It's basically a miracle material.
We didn't even know it was dangerous until the early 1900s and when you have miracle material ... | [
"Asbestos was one material historically used for fireproofing, either on its own, or together with binders such as cement, either in sprayed form or in pressed sheets, or as additives to a variety of materials and products, including fabrics for protective clothing and building materials. Because the material was l... |
What JSTOR essays should I download before I leave university and lose access? | Check [this list of universities](_URL_0_). When I graduated, no one told me that I still had Alumni Access to JSTOR provided by my school, and I only found this out several years later. There are about 100 schools that do apparently.
Edit: In the best /r/AskHistorians tradition, the dozen or so posts that are only a ... | [
"In early 2016, some users reported having received e-mails from Academia.edu where they were asked if they would be interested in paying a fee to have their papers recommended by the website's editors. This led some users to start a campaign encouraging users to cancel their Academia.edu accounts.\n",
"Authorea ... |
how do grass and trees survive prolonged sub-zero exposure? | Trees have the ability to not run water/nutrients close to the outside when its winter, this is somewhat to prevent freezing. This also creates age rings in the wood, since the water level and therefor color changes based on the temperature. | [
"While the perceived risk of death by falling trees (a part of the \"tree risk\" complex) is influenced by media and often hyped (the objective risk has been reported to be close to 1 : 10.000.000, almost as low as death by lightning), singular events have encouraged a \"proactive\" stance so that even lightly dama... |
When did "Autumn" start being called "Fall" in the United States? | You're assumption is incorrect. "Fall" comes from Old English, whereas "autumn" is a French import that only became predominant in British English well after the peak of English emigration to the American colonies.
_URL_0_ | [
"BULLET::::- In the UK generally the term \"fall\" meaning \"autumn\" is obsolete. Although found often from Elizabethan literature to Victorian literature, continued understanding of the word is usually ascribed to its continued use in America.\n",
"The alternative word \"fall\" for the season traces its origins... |
Why did the Sallet Helmet become near universally used by armored German Men at Arm and Knights? | This is a fascinating question touching on historical memory and armour fashions across Europe from the 15th into the 16th centuries.
The shortest answer is that the sallet -was- common across Western Europe, from central Europe and northeastern Europe all the way to Spain. In England and the Low Countries, it was nea... | [
"Germany delivered 5,400 visorless versions of the M1918 helmet for the Ottoman Empire. The missing front visor was thought by the Germans to be for religious reasons, and it was claimed that it was to allow Turkish soldiers to touch their foreheads to the ground during prayer, without removing their helmets. Howev... |
how does general anesthesia work? why is it so fast? | There are many kinds of general anesthesia. Broadly speaking, a drug can be used as a general anesthetic if (in a sufficient dose) it causes unconsciousness but doesn't kill you. Typically a general anesthetic causes unconsciousness that is at least somewhat resistant to stimulation, i.e. it knocks you out enough that ... | [
"Anesthesia is a combination of the endpoints (discussed above) that are reached by drugs acting on different but overlapping sites in the central nervous system. General anesthesia (as opposed to sedation or regional anesthesia) has three main goals: lack of movement (paralysis), unconsciousness, and blunting of t... |
Are all kinds of electromagnetic radiation made of photons? | Radio waves are light as well, just not in the visible part of the electromagnetic spectrum.
So to answer your question: Yes, all electromagnetic radiation is made up of photons. In fact a discrete excitation of a single electromagnetic mode *is* a photon. | [
"Due to this broad overlap in energy ranges, in physics the two types of electromagnetic radiation are now often defined by their origin: X-rays are emitted by electrons (either in orbitals outside of the nucleus, or while being accelerated to produce bremsstrahlung-type radiation), while gamma rays are emitted by ... |
music theory and how chords are constructed/used in different keys | Well, here's a small crash course. A "key" is a grouping of notes that can be used to construct chords or melodies that harmonize with each other. In Western music, the simplest key to learn is the key of C Major. Each key consists of eight notes, or an octave. In the key of C major, those notes are:
C D E F G A ... | [
"Methods that establish the key for a particular piece can be complicated to explain and vary over music history. However, the chords most often used in a piece in a particular key are those that contain the notes in the corresponding scale, and conventional progressions of these chords, particularly cadences, orie... |
What's the material that keeps your nails on your fingers? | After looking through Wikipedia, I can affirm to you that nails are kept on your finger by the same adhesion mechanisms as in normal cells; adherens junctions + desmosomes for lateral cell-cell adherence and hemidesmosomes for vertical cell-matrix adherence. All of those are composed of various proteins including cadhe... | [
"Racquet nails usually occur on one or both thumbs, but may appear on all fingers and toes. It may be genetic, inherited as an autosomal-dominant trait, or acquired. Genetic disorders associated with racquet nail include Larsen syndrome, Brooke–Spiegler syndrome, Rubinstein–Taybi syndrome, Hajdu–Cheney syndrome, ca... |
what is "smart grid" technology? | Personal Bias: I work for (and am invested in) an electrical utility and have been involved in the implementation of smart grid technology for that company.
----
Current situation: So right now, our electrical grid is SUPER old, and extremely outdated. Here are a few HUGE problems:
* You have to walk up to meter... | [
"A smart grid is a modernized electrical grid that uses information and communications technology to gather and act on information, such as information about the behaviors of suppliers and consumers, in an automated fashion to improve the efficiency, reliability, economics, and sustainability of the production and ... |
why bleach and products containing oxygen (like h2o2) have the power to whitening things? | They break down organic compounds very very easily. Most dyes and pigments are based on organic compounds, if I remember they are mostly dinitrile amines (or that was a key ingredient, I’ve tried to block my organic chem class from my mind).
So basically its a long chain organic compound and the charged oxygen is rea... | [
"Color safe bleach is a chemical that uses hydrogen peroxide as the active ingredient (to help remove stains) rather than sodium hypochlorite or chlorine. It also has chemicals in it that help brighten colors. Hydrogen peroxide is also used for sterilization purposes and water treatment, but its disinfectant capabi... |
why modern electric bikes aren't using a cvt transmission | *"Perfection is achieved, not when there is nothing more to add, but when there is nothing left to cut away."* - Antoine de Saint-Exupéry
Transmissions, like all real world mechanical devices are not 100% efficient. And when you have the energy density of a battery instead of gasoline, getting the most out of every ... | [
"CVTs should be distinguished from power-sharing transmissions (PSTs), as used in newer hybrid cars, such as the Toyota Prius, Highlander and Camry, the Nissan Altima, and newer-model Ford Escape Hybrid SUVs. CVT technology uses only one input from a prime mover and delivers variable output speeds and torque, where... |
What is known about the origins of the "four humours" concept of health and disease? | Most standard histories locate the origins of humoral theory in the Hippocratic-Galenic tradition. For instance:
> Historically, humoralism formed the basis for the Western tradition of medicine down to the nineteenth century. In its earliest manifestations, in sixth- and fifth-century BC Greece, it reveals no links ... | [
"There are still remnants of the theory of the four humors in the current medical language. For example, modern medicine refers to humoral immunity or humoral regulation when describing substances such as hormones and antibodies that circulate throughout the body. It also uses the term \"blood dyscrasia\" to refer ... |
in cities with grid layouts, why aren't traffic lights synchronized so that all lights on parallel roads turn green and red at the same times. | Stop lights are timed according to complex studies by transit authority to provide the best traffic flow that causes the least amount of accidents. Science has shown that for the most part that means a "ripple" type cascade of the lights turning in a given direction works better than all lights in that direction going ... | [
"These have two lights, usually mounted vertically. They are often seen at railway crossings, fire stations, and intersections of streets. They flash yellow or white when cross traffic is not expected, and turn red to stop traffic when cross traffic occurs (e.g., the fire engines are about to exit the station). The... |
How often (if ever) are previously unknown or lost works from the classical antiquity discovered today? | The Archimedes Palimpset is an extraordanary example of finding information from the classical world. The original work was actually a copy several generations removed from it's original, written in 950AD, and had it's writing scraped off to hold religious texts. Modern scholars rediscovered it in 1920's, but academic... | [
"Works—or, commonly, small fragments of works—have survived by being found by archaeologists during investigations, or accidentally by anybody. For example, the Nag Hammadi library scrolls. Works also survived when they were reused as bookbinding materials, quoted or included in other works, or as palimpsests, wher... |
How did Argentina keep the invasion of the Falkland Islands a secret? | It's possible that part of the US military establishment knew, but didn't divulge to the UK. The White House staff were divided as to which side back when the war kicked off, so this may have been reflected in the military as well. | [
"Despite initiating the war, Argentina had not prepared a plan for the subsequent defence of the islands. The military dictatorship that governed the country at the time regarded the seizure of the Falklands as a political act to obtain a diplomatic bargaining position, and not as an act of war. Consequently they w... |
is there any science or truth to a person like in the mentalist? | There are such things as real-world mentalists, if that's what you're asking. Mentalists such as James Randi and Banacek have made careers out of ousting psychic frauds. They've demonstrated that psychics who read minds or communicate with the dead loved ones of strangers often use a lot of techniques that Patrick Ja... | [
"\"The Mentalist\" follows Patrick Jane, an independent consultant for the California Bureau of Investigation (CBI) based in Sacramento, California. He has a remarkable track record for solving serious crimes by using his amazing skills of observation. Jane also makes frequent use of his mentalist abilities and his... |
why don't arid countries pump water from the sea to help with water issues? | Desalination is expensive and takes a fair amount of energy. Solar panels are expensive and take up a lot of space. | [
"The scarcity of fresh water resources is an issue in arid regions around the world, but is becoming more common due to overcommitment of resources. In the case of physical water scarcity, there is not enough water to meet demand. Dry regions do not have access to fresh water in lakes or rivers while access to grou... |
If Space and Time are interwoven, and Space is accelerating, is Time accelerating? | No, it isn't. The scale of the universe can be described as a spatial function that evolve in time (the Friedmann equation and its related solutions), but the scale of the time component is not affected by time. | [
"In physics, time is the fourth dimension. Physicists argue that spacetime can be understood as a sort of stretchy fabric that bends due to forces such as gravity. In classical physics the future is just a half of the timeline, which is the same for all observers. In special relativity the flow of time is relative ... |
why do most small towns have car dealerships? | Car dealerships use a lot of land area. You have to park a lot of cars. It's too expensive to pay rent in a big city. You can't be in the middle of nowhere either however because zoning and electricity and plumbing etc. | [
"Car dealerships are usually franchised to sell and service vehicles by specific companies. They are often located on properties offering enough room to have buildings housing a showroom, mechanical service, and body repair facilities, as well as to provide storage for used and new vehicles. Many dealerships are lo... |
Is this a Viking sword? | No. I'm sorry to have to disappoint you but this is quite definitely, without a doubt not a Viking sword. [This is what Viking swords look like.](_URL_2_) In fact it's unlike any European or Asian sword I have ever seen. It does remind me of African tribal swords, though. In fact, I am fairly certain that it is a Sudan... | [
"Several weapons (including the \"kesja\" and the \"höggspjót\") appearing in the sagas are Viking halberds. No weapon matching their descriptions have been found in graves. These weapons may have been rare, or may not have been part of the funerary customs of the Vikings.\n",
"Although popularly called \"Viking ... |
why can so many medical things be done in labs and on mice but we never hear of it ever again? | Let me tell you a secret, passed down from generations of scientists, and now I bestow this sacred knowledge onto you:
**People. Are. Not. Mice.**
While we do share a fair amount of genes with mice, we are too different to reliably predict the outcome of a medicine on humans by observing what happens to the mice.
M... | [
"Mice are part of human experimentation. Many of the tests are related to new products that are launched on the market, but they are also required to try new medicines for the cure of chronic and deadly human diseases.\n",
"Laboratory mice are often kept with several animals in one cage since mice are social anim... |
why are older artists like van gogh, michaelangelo, rembrandt and others so glorified and godified, while nowadays we see unknown artists that can draw/paint/carve things that look more true to life than those ever did? | I'll try to keep this short (I used to teach art history).
To put it simply: the story of art is the story of humanity, and throughout our history we have had different pursuits and priorities. Art, in any era, is going to be a reflection of those priorities, which is why you'd see less "realistic" art from medieval E... | [
"One of the most famous and most prolific of self-portraitists was Vincent van Gogh, who drew and painted himself more than 43 times between 1886 and 1889. In all of these self-portraits one is struck that the gaze of the painter is seldom directed at the viewer; even when it is a fixed gaze, he seems to look elsew... |
Do two laser beams crossing each other affect each other? | You'd get an interference pattern.
[diagram](_URL_1_)
[pic](_URL_0_) | [
"Two beams from a laser are injected into the same fibre but in opposite directions. Due to the Sagnac effect, the beam travelling against the rotation experiences a slightly shorter path delay than the other beam. The resulting differential phase shift is measured through interferometry, thus translating one compo... |
how do we adopt new fears and irrational phobias? | Most often a phobia (which is defined as an irrational* fear) is caused by a traumatic experience that featured the feared thing, or repeated negative association, usually in childhood.
For example, if you fell out of a tree as a child and were badly hurt, you might develop a fear of high places.
An adult that gets ... | [
" Though some fears are inborn, the majority are learned. Phobias develop through negative experiences and through observation. One way children begin to develop fears is by witnessing or hearing about dangers. Ollendick proposes while some phobias may originate from a single traumatizing experience, others may be ... |
when there was hyperinflation in germany, why didn't they just use the money they print to pay off the reparations | Because the money wasn't worth anything. That's what inflation means.
They literally burnt the money to stay warm, that's how useless it was. | [
"Since reparations were required to be repaid in hard currency, not the rapidly depreciating paper mark, one strategy that Germany used was the mass printing of bank notes to buy foreign currency, which was then used to pay reparations, greatly exacerbating the inflation of the paper mark.\n",
"Erik Goldstein wro... |
if water boils at 212°, then why is there water in the air? | There is water in a gas form in the air due to a process called evaporation. Evaporation creates water vapour. Evaporation is different to boiling water. When water reaches 212F it turns into steam.
There is only so much water that can stay suspended in the air as a gas (the water vapour) through evaporation. It will... | [
"Pure water boils at at earth's standard atmospheric pressure. The boiling point is the temperature at which the vapor pressure is equal to the atmospheric pressure around the water. Because of this, the boiling point of water is lower at lower pressure and higher at higher pressure. Cooking at high elevations, the... |
what a functional programming language is and what they are good for? | Functional programming languages are based around functions, usually the mathematical sense of functions. just as OO languages are based around objects. Functional programming languages generally try to avoid state and mutable variables and usual feature functions as first class entities, meaning that functions can tak... | [
"Programming in a functional style can be accomplished in languages that are not specifically designed for functional programming, such as with Perl, PHP, C++11, and Kotlin. An interesting case is that of Scala – it is frequently written in a functional style, but the presence of side effects and mutable state plac... |
if rain is a result of the water cycle, why do we have more rain in the autumn and winter when evaporation is presumably lower? | First: This is not true for a lot of places ([New York for example has the most rain in the summer](_URL_0_))
Second: For it to rain you do need water in the air - but you also need that water to condensate. There are certain things that will make it more likely to rain, that means favour condensation of water vapour ... | [
"\"Rising temperatures also increase the rate at which water evaporates (or transpires) into the air from soils and plants. Unless rainfall increases to the same extent as evaporation, soils become drier. As a result, the soil retains more water when it rains, and thus less water runs off into rivers, streams, and ... |
why does every single random app i want to download to my phone asks for access to all of my photographs, pictures and audio files? | This is *usually* not as sinister as it seems. When software developers make applications, they very frequently use pre-existing batches of code called libraries. These libraries include tools to access and manipulate all aspects of your phone and information. It's easier to include all the tools and lazy developers do... | [
"The app raises potential privacy issues arising from the tracking of a user's exact location, without them being notified that they are being tracked. Several safety features allow a user to share their location only with people they choose and turn off the permission at any time. \"Friends\" can only track users ... |
How can we hear noise from the sun? I've heard audio, and it sounds like a deep rumble. | You are not hearing a recording of sound waves from the sun. You are hearing the sonification of some other type of measurement. Without know what specific audio you are referring to, it is difficult to know what measurement was being made. | [
"Atmospheric noise is radio noise caused by natural atmospheric processes, primarily lightning discharges in thunderstorms. It is mainly caused by cloud-to-ground flashes as the current is much stronger than that of cloud-to-cloud flashes. On a worldwide scale, 3.5 million lightning flashes occur daily. This is abo... |
In AD500 would zoroastrianism have been the dominate religion in and around the place where Mecca now is? | No.
For a more detailed answer, see this similar question posted last month: _URL_0_ | [
"The early history of Mecca is still largely disputed, as there are no unambiguous references to it in ancient literature prior to the rise of Islam. The Roman Empire took control of part of the Hejaz in 106 CE, ruling cities such as Hegra (now known as Mada'in Saleh), located to the north of Mecca. Even though det... |
Does gravity affect all types of matter in the same way? | No. The weak [equivalence principle](_URL_0_) (which says that the strength of gravitational interaction affects matter in direct proportion to its inertial mass) implies that (from the wikipedia link above):
*"The trajectory of a point mass in a gravitational field depends only on its initial position and velocity, a... | [
"In Newton's description of gravity, the gravitational force is caused by matter. More precisely, it is caused by a specific property of material objects: their mass. In Einstein's theory and related theories of gravitation, curvature at every point in spacetime is also caused by whatever matter is present. Here, t... |
Citing the Rape of Nanking and their reaction to the Chinese populace after Operation Doolittle, why was there such an upsurge in the viciousness & cruelty of the Japanese people/army in the first half of the 20th century leading up to the end of WW2? | They're not 'out of step' more than they are the culmination of an expansionist policy that began in the 1890s and bred, as you suggested, a culture of invincibility and aggression. There's also evidence of a racial sense of superiority.
Japanese expansionist policies in WWII were based on several goals, ranging from ... | [
"The International Military Tribunal for the Far East did convict Japanese officers \"of failing to prevent rape\" in the Nanking Massacre, which is known as the \"Rape of Nanking\". The tribunal, in Tokyo, prosecuted cases of sexual violence and war rape as war crimes under the wording \"inhumane treatment\", \"il... |
Why did the Dutch East Indies became only one independent state (Indonesia) while all the other colonies in South and Southeast Asia fractured to become multiple independent states? | I won't speak to how the British Raj, British Malaya, and French Indochina fragmented, but I can speak to how Indonesia didn't become fragmented.
In short, it is a combination of:
* Effective suppression of organized independence movements under the Dutch.
* A new cadre of nationalist leaders developed by the Japa... | [
"From the arrival of the first Dutch ships in the late 16th century, to the declaration of independence in 1945, Dutch control over the Indonesian archipelago was always tenuous. Although Java was dominated by the Dutch, many areas remained independent throughout much of this time, including Aceh, Bali, Lombok and ... |
Did people watch East German programming in West Germany? | Yes, East German television was watched in West Germany. Many TV sets sold in West Germany at the time were specifically equipped to receive the East German SECAM colour TV signal in addition to the standard PAL code for this reason.The evening variety show "Ein Kessel Buntes" and the children's evening programme "Unse... | [
"In the early days, few West Germans and even fewer East Germans owned a TV set. Most Germans still preferred to go to the movies. One of the events that enhanced the popularity of TV among the West Germans was the broadcast of the 1954 football world cup finals from Bern, which many followed on TV screens in shop ... |
When did people start using "-ass" to emphasize adjectives? How did this practice start? | I hope it's ok if I make a quick suggestion that you also drop this question in a linguistics, or better yet a historical linguistics, subreddit. I hope to be surprised but in general historians are not likely to encounter these locutions to a degree that they can confidently answer this question, and we are not train... | [
"From the 18th century, \"donkey\" gradually replaced \"ass\", and \"jenny\" replaced \"she-ass\", which is now considered archaic. The change may have come about through a tendency to avoid pejorative terms in speech, and be comparable to the substitution in North American English of \"rooster\" for \"cock\", or t... |
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