question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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how did they know that is dinosaur skin ? | If the DNA was preserved enough to amplify and sequence that's probably how they identified it. Maybe along with dating the sample to an era where dinosaurs walked the earth | [
"\"Carnotaurus\" was the first theropod dinosaur discovered with a significant number of fossil skin impressions. These impressions, found beneath the skeleton's right side, come from different body parts, including the lower jaw, the front of the neck, the shoulder girdle, and the rib cage. The largest patch of sk... |
If the Earth was flat, would rainbows be straight lines? | Rainbows have nothing to do with the shape of the Earth, only to do with the refraction of light through (roughly) spherical raindrops. The refracted light spreads out in a cone and the part-circle we see is a cross-section through that cone. (If you are ever fortunate enough to experience a rainbow while flying in a p... | [
"In theory, every rainbow is a circle, but from the ground, usually only its upper half can be seen. Since the rainbow's centre is diametrically opposed to the sun's position in the sky, more of the circle comes into view as the sun approaches the horizon, meaning that the largest section of the circle normally see... |
how do they make the automated machines that are seen on shows like "how it's made"? | First design a machine that does just ONE job, but does it faster than humans can ever do (for example, putting labels on cans). Now design the next machine, same concept: one job, faster than humans until you have a different machine for every step of the manufacturing process. Then design a conveyor system to link it... | [
"\"'Machine' is based around the concept of computer simulation. The creatures, formed from sections cut and twisted from insects, crustaceans and bone are arranged in sculptural compositions inspired by artists such as Hieronymus Bosch; finding the surreal within mixed forms and scales. The movement for the creatu... |
how did accounting start? | Accounting actually seems to have started before the writing of words. Counting flocks and crop yields and such appears to have led to the development of numbers and methods for keeping track of them securely so that transactions could be reviewed at a later time if there was a need.
_URL_0_
> The earliest known wr... | [
"The history of accounting is thousands of years old and can be traced to ancient civilizations. The early development of accounting dates back to ancient Mesopotamia, and is closely related to developments in writing, counting and money; there is also evidence of early forms of bookkeeping in ancient Iran, and ear... |
Are there any cases that contradict the generalization that genocides are perpetrated only against groups that are both respected and loathed? | Did the Nazis respect the Roma? | [
"Geoffrey B. Robinson asserts that while there is no consensus on the matter, some scholars have described the mass killings as a genocide. Jess Melvin claims the 1965–66 massacre constitutes genocide under the legal definition as particular religious and ethnic groups where targeted collectively for their relation... |
Cavalry charges, in real life wouldn't the people in the back of the unit smash into the people in the front of the unit? | Often, a cavalry charge was *not* meant to end in physical shock; it was supposed to intimidate the enemy and break morale. If a line held, that meant significant risk to the horses and their riders from impalation on impact.
The best case scenario was for the infantry line, fearing the devastation of actual impact... | [
"Cavalry charges were made in closely packed formations, and were often aimed at the corners of the square (the weakest points of the formation.) Feints and false attacks would also be used to make the infantry \"throw away their fire\" by causing them to fire too early. However, if the infantrymen were well-discip... |
if earth had a longer day / night cycle would our body be able to adjust. | If the day were 48 hours long the heat balance would be off. Imagine the hot part of the day, now cook the earth for an additional 12 hours, and simultaneously cool the other side with the heat sink of outer space. I have no idea what that would do to the oceans, but I would expect a significant change.
Humans might... | [
"Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes, and 4 seconds with respect to other, distant, stars (see below). Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation.... |
During the Protectorate were there any proposals to crown Cromwell as a king? | There definitely were. It is the topic that dominates English political discussion from around May of 1649 up til Cromwell finally quashes it in 1657.
Charles I is beheaded in January 1649, around the same time that Thomas Fairfax, Lord General of the New Model Army, is getting out of politics and returning to priv... | [
"In 1657 Cromwell was offered the crown by Parliament, presenting him with a dilemma since he had played a great role in abolishing the monarchy. After two months of deliberation, he rejected the offer. Instead, he was ceremonially re-installed as \"Lord Protector of England, Scotland and Ireland\" (Wales was a par... |
How reliable is our knowledge on Gothic history? | A small disclaimer: I'm coming from an medieval / early-modern background, and this answer isn't completely applicable to more history.
I think we may need to come together and work out a little of what it means to "know" in history. I know that sounds really pompous, but I think it is pertinent to this question becau... | [
"Of special Gothic histories, besides that of Jordanes, already so often quoted, there is the Gothic history of Isidore, archbishop of Seville, a special source of the history of the Visigothic kings down to Suinthila (621-631). But all the Latin and Greek writers contemporary with the days of Gothic predominance m... |
what is the reasoning behind voting in the presidential election if the candidate can win the popular vote but still lose the election? | To keep more populous states like New York and california from completely strong-arming the entire election process over more rural and sparsely populated states like the dakotas. | [
"The result of the election is often determined by party politics. In most cases, the candidate of the majority party or coalition in the Bundestag is considered to be the likely winner. However, as the members of the Federal Convention vote by secret ballot and are free to vote against their party's candidate, som... |
why is cybercrime so hard to stop? | Because nobody really cares about cybersecurity except for nerds like me who see the face of normal people glaze over whenever we start evangelizing.
Because we're all pretty much using a bunch of technology in ways nobody ever intended, for a bunch of *ridiculously* sensitive information.
Because banks and other fin... | [
"As technology advances and more people rely on the internet to store sensitive information such as banking or credit card information, criminals increasingly attempt to steal that information. Cybercrime is becoming more of a threat to people across the world. Raising awareness about how information is being prote... |
karma calculation | Self-posts grant no karma.
Karma numbers on comments and posts are fudged to prevent people who run vote-bots from knowing if the bot has been shadow-banned or not. Otherwise, karma and upvotes are a 1-to-1 relationship; 1 upvote is 1 karma. If you're upvoting yourself from a second account and it's not registering, ... | [
"A user who has a karma of at least 5 is able to contribute to someone’s else karma value, increasing or decreasing its value by 1. The contribution can be changed later. The number of karma changes per day is limited with one's own karma value (for example, a user with 7.00 can vote 7 times a day).\n",
"Karma is... |
how come the /70's/80's/90's seem so distinctive yet the 2000's and 2010's don't seem to have distinct personalities? | Because they're still too close to view with much objectivity, and are blending together in your perception. While decades in close proximity to each other will have a lot of common influences, they do have distinct characteristics--and you'll start to notice them more as more time passes. We're only halfway through th... | [
"The term \"'Me' Decade\" describes a general new attitude of Americans in the 1970s, in the direction of atomized individualism and away from communitarianism, in clear contrast with social values prevalent in the United States during the 1960s.\n",
"That '80s Show is an American sitcom that aired from January t... |
why is soda + ice cream (aka a float) tasty but soda + milk gross? | Because ice cream is loaded w/ sugar, cream, and flavoring. Milk is not. | [
"An ice cream float or ice cream soda (United States, United Kingdom, Canada, South Africa and East Asia), coke float (United Kingdom and Southeast Asia), or spider (Australia and New Zealand), is a chilled beverage that consists of ice cream in either a soft drink or in a mixture of flavored syrup and carbonated w... |
how tax cuts reduce unemployment. | I have lots of money, but I'm lazy. I don't want to do any work. So I invest my money in this cool company that needs funding. The cool company hires a bunch of people with my invested money and they all get jobs. Once the company makes enough money to pay me back (with interest), they pay me back. The lower the taxes,... | [
"It is unclear whether lowering marginal income tax rates boosts job growth, or whether increasing tax rates slows job creation. This is due to many other variables that impact job creation. Economic theory suggests that (other things equal) tax cuts are a form of stimulus (they increase the budget deficit) and the... |
how can my dog go from sitting by the fire to outside in the snow without apparently be bothered by the huge change in temperature? | They have fur which insulates them.
EDIT: words. | [
"Dogs can stand, walk and run on snow and ice for long periods of time. When a dog's footpad is exposed to the cold, heat loss is prevented by an adaptation of the blood system that recirculates heat back into the body. It brings blood from the skin surface and retains warm blood in the pad surface.\n",
"Dogs are... |
does the immune system have a maximum learning capacity for vaccinations? | There can be a problem with your immune system being full of memory T cells for pointless things, but vaccines are not going to cause this.
[CMV](_URL_0_) (Cytomegalo virus) is the biggest risk in this regard. It is endemic in the population, about 90% of people have it. It mutates very very rapidly, and is incredibly... | [
"Acquired immunity creates immunological memory after an initial response to a specific pathogen, and leads to an enhanced response to subsequent encounters with that pathogen. This process of acquired immunity is the basis of vaccination. Like the innate system, the acquired system includes both humoral immunity c... |
Did Malaysia kick out Singapore from the Union in 1965 or did the Singaporean leadership wanted to break away on their own? | Even though it has been 2 months, as a Singaporean I must answer your question.
(For this post, abbreviations: SG = Singapore, SGean = Singaporean, M'sia = Malaysia, M'sian = Malaysian)
Sources vary on whether SG left on its own because of the PAP or whether M'sia's ruling party evicted Singapore. The common consensu... | [
"On 7 August 1965, Prime Minister Tunku Abdul Rahman, seeing no alternative to avoid further bloodshed, advised the Parliament of Malaysia that it should vote to expel Singapore from Malaysia. Despite last-ditch attempts by PAP leaders, including Lee Kuan Yew, to keep Singapore as a state in the union, the Parliame... |
Are there more/different platonic solids in non-Euclidean geometries? | **Short answer:** No.
**Long answer:**
> But in non-Euclidean geometry, regular polygons have different internal angles.
This is certainly true, and the reason why the argument given in the video does not generalize to non-Euclidean spaces. However, there is another way to prove that there are only 5 Platonic soli... | [
"The Platonic solids are three-dimensional shapes with special, high, symmetry. They are the next step up in dimension from the two-dimensional regular polygons (squares, equilateral triangles, etc.). The five Platonic solids are the tetrahedron (4 faces), cube (6 faces), octahedron (8 faces), dodecahedron (12 face... |
Helium balloon on Mars -- what happens? | It blows and bursts immediately.
You have around 0.01 atm on the surface of Mars if I recall correctly.
At equilibrium you have P = (NkT)/V for the helium meaning that if you divide the pressure by 100 you get a 100-fold increase in volume.
This is around a 4.6-fold increase in radius and party balloons definitely c... | [
"Fully inflated, a balloon of this size would contain just over of helium. Helium's lift capacity at sea level and 0 °C is 1.113 kg/m (0.07 lbs/ft) and decreases at higher altitudes and at higher temperatures. The volume of helium in the balloon has been estimated as being able to lift a total load, including the b... |
is there a level of sugar in water at which if cotton candy was added, it wouldn't dissolve? | Yes.
Think about continuing to add sugar to the water until all the water has been absorbed by the sugar. At this point, there is no available water to cause the cotton candy to dissolve.
Of course, at this point your sugar water solution is no longer a liquid. | [
"BULLET::::- Liquid sugars are strong syrups consisting of 67% granulated sugar dissolved in water. They are used in the food processing of a wide range of products including beverages, hard candy, ice cream, and jams.\n",
"When any one form of a sugar is purified and put in water, it rapidly takes other forms of... |
why do we instinctively want to say things in certain orders. e.g "the big red hammer" sounds good but "the red big hammer" sounds unnatural when both are grammatically correct? | It's cultural, and it's also the way we convey significance. If there were 2 big hammers and you preferred the red one, you'd say red first because it clarifies what you mean. In French they say the noun first, adjective 2nd which would sound bizarre in English. | [
"The phrase 'the three Rs' is used because each word in the phrase has a strong \"R\" phoneme (sound) at the beginning. The term is ironic, since someone with rudimentary language education would know that two of the original words do not actually begin with the letter \"R\". The third \"R\" was more probably Recko... |
how do i use a ssh tunnel to log onto websites? | They are probably meaning that you should set up an ssh tunnel to an external computer (such as a rented server space, or in principle your home computer), and route all your traffic through it. I don't know how to do this offhand, and to be honest nobody is likely to walk you through the process on ELI5, it's a techni... | [
"SSH tunneling: By establishing an SSH tunnel, a user can forward all their traffic over an encrypted channel, so both outgoing requests for blocked sites and the response from those sites are hidden from the censors, for whom it appears as unreadable SSH traffic.\n",
"SSH tunnels provide a means to bypass firewa... |
why can't people withdraw their money from a bank that goes bankrupt? specifically those regular savings accounts? that supposedly have no such risk as it's a saving, not an investment. | Any money you put into a bank they use to lend to others. If they go bankrupt then they have absolutely nothing left and your money is gone | [
"However a different outcome is also possible. Since banks lend out at long maturity, they cannot quickly call in their loans. And even if they tried to call in their loans, borrowers would be unable to pay back quickly, since their loans were, by assumption, used to finance long-term investments. Therefore, if all... |
how glass gains its characteristics such as sound proof, bullet proof, tempered, flexable, etc. | tempered glass in heat treated in such a way that it changes the glass molecularly. Bullet proof glass isnt bullet proof, its bullet resistant. The way that works is that it is really several pieces of glass laminated together. The lamination and the different pieces of glass work together to make it more bullet resi... | [
"Glass is relatively hard and heavy in comparison to metal or plastic and therefore produces a greater range of tone than these materials. Glass can be polished to a smooth or rough texture depending on the grit of sandpaper used. Likewise, factors such as size, shape, and weight have a much more dramatic effect on... |
why do formula 1 cars require a certain amount of heat in the brakes and the tires to turn and stop quickly? | Think about a piece of paper dragging across the table.
If the paper is dry it slides easily. It is hard and barely touches the table. There is very little friction.
If the paper is wet it won't slide at all. It is soft and sticks to the table. There is a lot of friction and the paper will stop quickly.
Heating th... | [
"The brakes include a prefill function whereby the pistons in the calipers move the pads into contact with the discs on lift off to minimize delay in the brakes being applied. This combined with the ABS and standard Carbon Ceramic brakes have caused a reduction in stopping distance from 100–0 km/h (62-0 mph) to . T... |
without having a biased response, what exactly is sally yates role in the investigation with russia? | Sally Yates was the acting attorney general. (Meaning, she stayed on from the Obama administration while Trump waited for his new attorney general, Jeff Sessions, to be confirmed)
In December 2016, President Obama imposed sanctions on Russia.
In January 2017, it came out that General Flynn (who Trump had picked to b... | [
"Commenting on the end of the trial against a few suspects in Moscow yesterday, Andrew McIntosh, Chairman of the Council of Europe Parliamentary Assembly's Sub-Committee on the Media and Rapporteur on media freedom, expressed his deep frustration at the lack of progress in investigating the murder of Anna Politkovs... |
How and why does your eye and brain react to light intensity? | the words that will facilitate your search is *visual transduction*
Eye damage will occur with too much UV or thermal damage from too much IR which there is quite a bit from the sun. | [
"In the visual system, sensory cells called rod and cone cells in the retina convert the physical energy of light signals into electrical impulses that travel to the brain. The light causes a conformational change in a protein called rhodopsin. This conformational change sets in motion a series of molecular events ... |
Why did gratuitous torture used to be perfectly acceptable? | For one thing, it wasn't gratuitous. As you yourself already said, it was part of executions, which were undertaken as retribution for crimes.
On why people went to witness that, I'll have to say, as I always do with these kinds of questions, that anything we can elucidate is quite speculative, due to the nature of th... | [
"Others point out that the ticking-bomb torture proponents adopt an extremely short-term view, which impoverishes their consequentialism. Using torture—or even declaring that one is prepared to accept its use—makes other groups of people much more likely to use torture themselves in the long run. The consequence is... |
if temperature is defined by the average kinetic energy of something, how does a fan blowing on me not feel warmer than room temperature? | Your body cools itself via evaporation: vapors and gasses can carry away a great deal of heat as they evaporate or transition from liquid to gas; it's the same principle that makes spray cans and refrigerators cold. That's why you perspire. Even if you're not perspiring heavily enough to produce drops running down you... | [
"A standard cooling fan is essentially a bladed DC motor. By varying the voltage input across the acceptable range for a fan, the speed of the fan will increase (to added voltage) and decrease (to reduced voltage); a faster fan means more air moved and thus a higher heat exchange rate. There are a few ways to perfo... |
how do ants walk on walls? | Ants, like (probably?) every other insect, have little [pincers for feet](_URL_0_). This allows them to grab onto walls and ceilings. They hardly weigh anything, so they can easily hold their weight on the wall/ceiling. | [
"The ant appears to use an internal pedometer to count its steps in a harsh environment where odors quickly vanish, enabling it to \"count back\" to its nest. When stilts were glued on to the ants legs, they overshot the distance of their nests, while ants with cut legs traveled short of their nest. It's suspected ... |
A question about 1920s Berlin culture of decadency. | Although the Weimar Republic has since the 1930s become somewhat synonymous with decadence and sexual freedom, this experience was far from universal nor was it completely unchallenged. Although individuals advocating sexual freedom like Hirschfeld emerged as public intellectuals in the Republic, it does not necessari... | [
"The 1920s saw a remarkable cultural renaissance in Germany. During the worst phase of hyperinflation in 1923, the clubs and bars were full of speculators who spent their daily profits so they would not lose the value the following day. Berlin intellectuals responded by condemning the excesses of capitalism, and de... |
will we ever run out of space for satellites to orbit the earth? | We already allocate some orbits through international agreements. Putting a satellite in a geosynchronous orbit, an orbit that takes 24 hours to complete meaning the satellite appears to remain in the same place in the sky all the time, requires a lot of coordination between satellite operators. While the risk of a p... | [
"Computer models by astrophysicists Mikael Granvik, Jeremie Vaubaillon, and Robert Jedicke suggest that these \"temporary satellites\" should be quite common; and that \"At any given time, there should be at least one natural Earth satellite of 1 meter diameter orbiting the Earth.\" Such objects would remain in orb... |
How common was Allied forces using confiscated Axis weapons in WWII? | It was not a very common practice overall. While some Allied soldiers did use Axis equipment, it was often more out of temporary necessity than practice. Using enemy equipment on the frontlines was often hazardous and its problems outweighed its benefits.
Highly advanced technical equipment like new aircraft models w... | [
"Axis forces employed biological and chemical weapons. The Imperial Japanese Army used a variety of such weapons during its invasion and occupation of China (\"see Unit 731\") and in early conflicts against the Soviets. Both the Germans and Japanese tested such weapons against civilians, and sometimes on prisoners ... |
Have the petroglyphs found on the Keweenaw peninsula of Michigan been proven to be legitimate? (Carved thousands of years ago?) | I have friends in the UP from L'Anse and have gone up there fairly often. I hadn't heard about the petroglyphs. Can you provide details or a link ad hopefully pictures? I'll ask for you. | [
"The first person to publish about the petroglyphs was Herbert Basedow, having examined several sites from the Panaramitee region. In this publication he also made the first qualified claims for the Pleistocene antiquity of rock art outside of Europe.\n",
"The petroglyphs include depictions of swirls, lines, hand... |
What happens to the plant and animal DNA in food that we eat? Does it get broken down by the digestive system or is it just waste product? | Simply put, yes. DNA (and RNA) constitute polymers of [nucleic acids](_URL_1_), which, when enter your digestive system, will be degraded and broken down by [nuclease](_URL_0_) (and other) enzymes in your digestive tract. Nucleases cleave the [phosphodiester] bonds between the nucleic acids, thus breaking down the poly... | [
"Protein degradation may take place intracellularly or extracellularly. In digestion of food, digestive enzymes may be released into the environment for extracellular digestion whereby proteolytic cleavage breaks proteins into smaller peptides and amino acids so that they may be absorbed and used. In animals the fo... |
why colleges require that we take classes that aren't particularly related to our carrer interest/major? | College isn't just about getting a degree, it's about building life skills and gaining experience that will benefit you in the "real world".
Philosophy helps you think "outside the box". Writing helps you express yourself eloquently. Literature helps you learn to imagine others complexly.
Specifically, foreign lang... | [
"BULLET::::- There is a historic connotation that community colleges and for-profit colleges are often considered schools of last resort, because of their open-admissions policies, which may reflect poorly upon students who were unable to receive admission to a college offering a wider variety of degree programs. T... |
why are construction machines (backhoes, loaders, bulldozers) always yellow? | Very simple answer for this. When you are shown a color circle, the one that stands out the most is almost always yellow. Yellow is the color that most easily gets your attention so it is important to help you imminently see the dangerous equipment. | [
"The cars had an aluminium-alloy double-skinned construction, and were delivered unpainted to save time. A red adhesive strip ran through the length of the cars in the middle to match the operator's visual branding. The unpainted cars had a shiny appearance upon delivery, but as dirt and grime accumulated it became... |
how do airports and airlines coordinate schedules across the globe? | Busy airports assign a specific number of landing and takeoff slots to airlines. The airline negotiates the time of those slots and then uses those to determine what their flight schedule should be from city to city. They also take into account what flights their competitors are offering, and often adjust their sched... | [
"Schedule time is the difference between the scheduled local time at the origin and the scheduled local time at the destination and usually differs from the actual time in the air as it is affected by the local time zones. Local clock time flying westward, or \"chasing the sun\", is slowed, while local clock time f... |
I've heard that the census in which Jesus was supposed to be apart of was not during his lifetime, but in fact years before. Is this true? | Not years before, but afterwards. Essentially, the question is about the census mentioned in Luke's Gospel, where he talks about a census in the time of Quirinius as governor of Syria. The problem is that Josephus doesn't mention a census under Quirinius until 6AD, and we don't have any evidence that Qurinius was gover... | [
"The lines of evidence used to establish Jesus' historical existence include the New Testament documents, theoretical source documents that may lie behind the New Testament, statements from the early Church Fathers, brief references in histories produced decades or centuries later by pagan and Jewish sources, gnost... |
why does fox keep cancelling popular shows such as b99 and lucifer? | People don’t think the shows are as great as you do so they don’t tune in and the fuck it doesn’t make enough money so they canceled it | [
"On May 11, 2018, following the series' initial cancellation, co-showrunner Joe Henderson indicated that the third season finale would feature a \"huge cliffhanger\" that was meant to deter Fox from cancelling the series and encouraged fans to \"make noise\" with the hashtag #SaveLucifer. Fans, as well as the cast ... |
When did army officers start carrying rifles into battle? | I can't comment upon the Americans, but for the British army the change arguably came with the introduction of the L85 rifle (if I stick to the letter of your question). Previously, officers had carried sub-machine guns, or before this pistols. The reason why was due to the fact that they were not generally called upon... | [
"Many revolving rifles were purchased for the use of the militia of various states, and many militia companies entered the Civil War armed with them and never really used them in combat situations. The Colt Company made a number of sizes in the attempt to adapt the rifles to the various branches of the service. Whe... |
how can _url_0_ keep all those photos stored on their servers? | Of course the actual answer is a lot more complicated than "on big hard drives" - as there's probably many layers of complexity between "user uploads photo" and "photo ends up on a hard disk".
So what's likely happening is:
* Photo is uploaded
* A service at imgur resizes the photo, assigns it a unique name, and coll... | [
"The catalog enables filtering by folders, keywords, and the date when the photos were created. Storing photos on the external drives is supported, also there is an integrated access to photos on cloud storage.\n",
"BULLET::::- Documents folders are for storage and can be made accessible to members or just admini... |
why is samsung able to release new technology/products at such as fast rate and apple waits so long to release new tech/products? | Different marketing schemes. Samsung's plan is to offer a variety of products that fit whatever needs you have. Apple's plan is to offer one product that can do "most" of what "most" people want. Each has its pros and cons, but it's not a question fo one being "able" to release new products while the other is not. | [
"In Q1 2008 Samsung shipped 46.3 million mobile handsets 1Q 2008. Sales of Samsung Telecommunications were 6.65 trillion KRW for the same quarter and it represents 32% sales of Samsung Electronics. The growth is mostly explained by the continuous growth of emerging markets while there is weak demand in developed ma... |
how do crows and other birds with one "call" communicate? | The simple answer is they don't have a single call...birds, including crows have dozens of known calls which vary in length, pitch, tone, and sequence. The context in which the call is given can also give the receiver clues about its meaning and intent. Its difficult for an ordinary person to distinguish these calls bu... | [
"The most usual call is a loud, short, and rapid \"\". Usually, the birds thrust their heads up and down as they utter this call. American crows can also produce a wide variety of sounds and sometimes mimic noises made by other animals, including other birds.\n",
"Crows and the other members of the genus make a w... |
Can electricity pass between magnets? Can information? | Electricity is moving electrons, so by definition, no electriity can pass where there are no moving electrons.
You can, however, transfer energy by oscillating a magnetic field in a certain way with a certain setup. A team at MIT founded a company based on this. It's called Witricity (wireless electricity).
Similar... | [
"\"The agreement of the results seems to show that light and magnetism are affections of the same substance, and that light is an electromagnetic disturbance propagated through the field according to electromagnetic laws.\"\n",
"Instead, magnetism in ordinary matter comes from two sources. First, electric current... |
How far east/south did Christianity spread prior to European missionary trips? | This is my "at least" answer:
Nestorian Christianity spread at least as far as Mongolia (Ghengis Khan's wife Sorghaghtani Beki was a Nestorian). Abyssinia (modern day Ethiopia and the Horn of Africa) was a Christian empire in the 7th century CE. | [
"Meanwhile, the discovery of America by Christopher Columbus in 1492 brought about a new wave of missionary activity. Partly from missionary zeal, but under the impetus of colonial expansion by the European powers, Christianity spread to the Americas, Oceania, East Asia and sub-Saharan Africa.\n",
"During the Age... |
Interesting question on ELI5: How did Prom King/Prom Queen come to be? | Thanks for asking this. Just wanted to do it myself. | [
"\"Prom Queen\" is the twentieth episode of the second season of the American musical television series \"Glee\", and the forty-second overall. It aired May 10, 2011 on Fox in the United States. The episode was written by series creator Ian Brennan, directed by Eric Stoltz, and featured the return of guest star Jon... |
why haven't we found a way to permenantly remove hair for good? is it even possible? | Electrolysis is permanent and has been around for a while. However it is time consuming, can be very painful, and is prohibitively expensive for large areas | [
"Hair removal at the location where the surgical incision is made is often done before the surgery. Sufficient evidence does not exist to say that removing hair is a useful way to prevent infections. When it is done immediately before surgery, the use of hair clippers might be preferable to shaving.\n",
"Forms of... |
what is the difference between slander, libel and defamation? | Defamation is when you make a false statement to a third party that damages the reputation of the targeted party.
I stress the third party because it is not defamation if you make a false claim to the person directly; it has to be directed to somebody else. Slander and libel are both forms of defamation. Slander is... | [
"\"Defamation\" is the general term used internationally, and is used in this article where it is not necessary to distinguish between \"slander\" and \"libel\". Libel and slander both require publication. The fundamental distinction between libel and slander lies solely in the \"form\" in which the defamatory matt... |
Which future battery techs are the most viable and what limitations keep them from being used today? | as an engineer in manufacturing the biggest thing is turning some new concept or lab experiment into something that's mass produceable at a reasonable cost. Also generally there's not a lot of expertise to go from high level science to factory making the bits. The PHD folks who invent new technology tend to drastical... | [
"By making it easier for consumers to use reusable battery technology, The BETTERY brand reduces the volume of batteries that are thrown away in the U.S. every year. Approximately 90 percent of portable batteries manufactured in the US are alkaline dry cells with a global annual production exceeding 10 billion unit... |
Why did the proliferation of dreadnoughts end during the interwar period? | If I understand it correctly, Dreadnoughts were less a new type of ship as much as a class of battleship based on the HMS Dreadnought that came to be the predominate type of battleship.
As to why there were so many fewer in the interwar period that mostly has to do with the five-power treaty which limited the battlesh... | [
"Within five years of the commissioning of \"Dreadnought\", a new generation of more powerful \"super-dreadnoughts\" was being built. The arrival of the super-dreadnought is commonly believed to have started with the British . What made them 'super' was the unprecedented 2,000-ton jump in displacement, the introduc... |
What's the current historiography on Reconstruction? | This is a little after my time but I'll give it a go. Your first stop for reading should be Foner's *Reconstruction*. Get the new edition and Foner adds a forward reviewing historiography since 1988 up to about 2011. Beyond that, the main trends in major Reconstruction works since Foner have been to highlight the viole... | [
"In the past twenty years, no period of American history has been the subject of a more thoroughgoing reevaluation than Reconstruction—the violent, dramatic, and still controversial era following the Civil War. Race relations, politics, social life, and economic change during Reconstruction have all been reinterpre... |
How is the great attractor pulling everything to it, despite the universe still expanding from the Big Bang? | It's not pulling galaxies "back," just "toward it"." Even as the universe expands, galaxies, superclusters, and everything else still feel the effects of gravity from each other. | [
"Lynden-Bell et al. (1988) dubbed the cause of this the \"Great Attractor\". The Great Attractor is now understood to be the center of mass of an even larger structure of galaxy clusters, dubbed \"Laniakea\", which includes the Virgo Supercluster (including the Local Group) as well as the Hydra-Centaurus Superclust... |
What was the social and political response of settling Vietnamese refugees in the US during/following the Vietnam War? | "Wide hostility found to Vietnamese Influx: hostility found across the Country as the first south Vietnamese exiles arrive, economic impact is cited by most." That was a *New York Times* headline on May 1, 1975 -- just a day after the fall of Saigon.
The refugee problem elicited contradictory response, some opposing i... | [
"Although the U.S. Army maintained that the refugees were fleeing communism, an Army study in mid-1966 concluded that U.S. and South Vietnamese bombing and artillery fire, in conjunction with ground operations, were the immediate and prime causes of refugee movement into South Vietnamese government controlled citie... |
how do bills and fines work for foreigners? | 1. medical expenses, hospitals would most likely use debt collection agencies, these agencies would have contacts in other countries. The foreign agencies may be able to turn the case to local authorities, or settle it in court.
2. Traffic fines. Traffic fines obviously are handled by the authorities, they would be a... | [
"In some circumstances, such as with U.S. government workers and more widely with police officers, receiving gratuities (or even offering them) is illegal; they may be regarded as bribery. A fixed percentage service charge is sometimes added to bills in restaurants and similar establishments. Tipping may not be exp... |
i'm not allowed to donate blood because i'm on multiple mood altering meds. why am i allowed to be an organ donor? | There are techniques that can filter literally anything out of blood/tissues. But they are expensive both in time and money, or at least expensive enough to make it inefficient to take your blood (because they can take it from somebody else that doesn't require filtering).
Organs are WAY more rare, so if you can get a... | [
"In 2012, the Constitutional Court found that one's sexual orientation cannot be a criterion for preventing blood donation, for this purpose the Court ordered the Ministry of Health and Social Protection to change the current regulations which established that persons with homosexual orientation could not donate bl... |
why do banks charge a "service fee"? | Because it costs them some amount of money to do a particular act, either a computer or a person has to handle it. Since that costs money, and you will willingly pay that money, they charge you for it. | [
"Bank fees are assessed to customers for various services and as penalties. There are unauthorised overdraft fees, ATM usage fees, and fees for having an account balance below the minimum daily balance. Some banks charge a fee for using tellers in an effort to encourage customers to use automated services instead. ... |
why didn't either of the wtc towers collapse sideways? | Gravity pulls downwards. The building had a massive amount of weight, a lot of empty space, and didn't fall from being nudged over it took time to fall after the impact due to the fires decreasing the yield strength of the building supports. The building reached a point where it couldn't support its own weight, so g... | [
"The report concludes that the fireproofing on the Twin Towers' steel infrastructures was blown off by the initial impact of the planes and that, if this had not occurred, the towers would likely have remained standing. The fires weakened the trusses supporting the floors, making the floors sag. The sagging floors ... |
Why doesn't the Bible mention the Sea People? | As a related add-on question (that is connected):
I heard that one theory is that the Philistines were part of what's known as the "sea people". How likely is that? It'd certainly explain why they're not mentioned in the Bible (because they are, but not called Sea People). | [
"All Old and New Testament writers use the term \"sea\" (Hebrew יָם \"yam\", Greek θάλασσα), with the exception of Luke who calls it \"the Lake of Gennesaret\" (), from the Greek λίμνη Γεννησαρέτ (\"limnē Gennēsaret\"), the \"Grecized form of Chinnereth\" according to Easton (1897).\n",
"The Sea Peoples remain un... |
h+ and oh- ions role in electroplating. | Not going into deep chemistry, these ions doesn't do much in electroplating.
Electroplating is when you attract ions of a metal with electric current onto another metal. You don't bother with other ions during that process. Every mole of coated metal equals to one mole of dissolved metal on the other electrode, so H3O... | [
"The name refers to the fact that the electrode is in the actual electrolyte solution and not separated by a salt bridge. The hydrogen ion concentration is therefore not 1, but corresponds to that of the electrolyte solution; in this way we can achieve a stable potential with a changing pH value. \n",
"This elect... |
why do cats get "the zoomies"? | Cats spend the majority of their time grooming, eating, and sleeping (mostly sleeping). They need some way to burn off their energy, so they run around like crazy. It even has a fancy name- "frenetic random activity period." | [
"The Cat brings in a big red box from outside, from which he releases two identical characters, or \"Things\" as he refers them to, with blue hair and red suits called Thing One and Thing Two. The Things cause more trouble, such as flying kites in the house, knocking pictures off the wall and picking up the childre... |
why do americans love pickup trucks so much ? | Part of it, is that the US doesn't pay as much for fuel as many European/Scandinavian countries. On average, we pay about half of what you do for fuel. Therefore, having a utility vehicle that gets poor gas mileage is not as big of a luxury as you might think.
Trucks are useful. Many of my relatives are tradesmen and... | [
"A pickup truck is a light-duty truck having an enclosed cab and an open cargo area with low sides and tailgate. Once a work tool with few creature comforts, in the 1950s consumers began purchasing pickups for lifestyle reasons, and by the 1990s, less than 15% of owners reported use in work as the pickup truck's pr... |
how do musicians interpret the conductor's arm/baton movements as specific instructions for their particular contribution? is there some sort of known movement to scale extrapolation or musical empathy or even him just being there for show? | This is a hard one to explain. But basically the conductor's movements really tells the band how to play.
As you get more and more advanced in your playing the conductor becomes less useful in telling you the time signature and beat of the music and more useful in keeping everybody in line and telling everybody what t... | [
"Orchestras are usually led by a conductor who directs the performance with movements of the hands and arms, often made easier for the musicians to see by use of a conductor's baton. The conductor unifies the orchestra, sets the tempo and shapes the sound of the ensemble. The conductor also prepares the orchestra b... |
how do knife/tomahawk throwers know that the head of the axe/knife is going to hit their target? | I took an axe throwing class last summer.
A well thrown axe always revolves a certain number of times when thrown a specific distance with a specific amount of force. By practicing different types of throws from these specific distances, an experienced thrower can make every throw land.
Different distances require di... | [
"The \"axe head\" is typically bounded by the \"bit\" (or blade) at one end, and the \"poll\" (or butt) at the other, though some designs feature two bits opposite each other. The top corner of the bit where the cutting edge begins is called the \"toe\", and the bottom corner is known as the \"heel\". Either side o... |
Did the allies/soviets dictate a new curriculum for German schools? | I can put in some insight on the Soviet side. In the 1920's Eastern Europe developed very progressive schooling with a lot of child centered curriculum. Germany, Poland, Czechoslovakia and Hungary had developed advanced pedagogies that they expected a left wing regime to support.
Instead the USSR imported the ideas o... | [
"After World War II, the Allied powers (Soviet Union, France, United Kingdom, and the U.S.) ensured that Nazi ideology was eliminated from the curriculum. They installed educational systems in their respective occupation zones that reflected their own ideas. When West Germany gained partial independence in 1949, it... |
the pumping lemma | For a handful of academic fields and topics (such as computer science, compilers, etc.), there's a fundamental need to know if languages are called *regular*. The languages aren't languages like English, French, German, etc. The languages are simply languages along the lines of more computerish languages. For example... | [
"The pumping lemma is often used to prove that a particular language is non-regular: a proof by contradiction (of the language's regularity) may consist of exhibiting a word (of the required length) in the language that lacks the property outlined in the pumping lemma.\n",
"In computer science, in particular in f... |
why are a lot of old games (halo, wow classic, etc.) starting to re surge and be re released after 10+ years from when they were made? | Nostalgia tends to work on a decade cycle.
There's a grown up now who remembers playing Halo, etc as a kid.
That grown up now has free money he can spend however he wants.
So he remembers having fun as a kid, and the companies give him the same thing he played as a kid just updated.
So the grown up has fun, and... | [
"The game was officially discontinued on November 17, 2011 due to incompatibility issues with sound cards in newer computers. Although Her Interactive released a remastered version of its first game \"\", they have not announced plans to remaster any other older games, including \"Stay Tuned for Danger\".\n",
"An... |
why do different people like different climates? | I live in the Las Vegas Valley and chances are if you lived here long enough you grew a tolerance to heat, went to Norwalk (east of los angeles) and I was FREEZING.
After long periods of time we get used to the temperatures in our enviroment, the same way early humans adopted to breathing atmospheric oxygen. | [
"Not all cities show a warming relative to their rural surroundings. After trends were adjusted in urban weather stations around the world to match rural stations in their regions, in an effort to homogenise the temperature record, in 42 percent of cases, cities were getting \"cooler\" relative to their surrounding... |
what makes 70mm film screenings different? (i.e. dunkirk) | For one, it's not a digital projection. Most movies you go see in a theater are projected digitally, but if you had gone 15 or so years ago, they would have all been projected with film. There is an ongoing debate about which is better. Digital tends to show a cleaner picture, but the detail is limited to a certain ... | [
"Christopher Nolan used 15/70mm IMAX cameras again on his next film, \"Dunkirk\". However, unlike the previous films, where he used the cameras for select sequences, Nolan used IMAX as the primary shooting format, with 75% (about 79 minutes) of the 106-minute film featuring footage shot in 70mm IMAX (breaking the a... |
across different western languages, why are there names that share an obvious common root while the languages don't? | Russian and English both belong to the Indo-European family. But that's actually not the reason, since you have Hungarian, which is not Indo-European, and has recognizable names ─ Miklós, Jószef, Mihály.
The real reason is shared heritage/culture. All European countries are, or have been in the past, heavily Christian... | [
"There are a number of place names that seem unusual to English speakers because they do not conform to standard English orthography rules. Examples include the Welsh towns of Ysbyty Ystwyth and Bwlchgwyn which appear to English speakers to contain no vowel characters, although \"y\" and \"w\" represent vowel sound... |
why do rocks seem to be dull and colorless when dry but explode with color and character when they’re wet? | Several reasons, the major one at play is that it changes how the light reflects off the surface. It consolidates the light and allows it to be seen from one direction. The water also creates a new smoother surface that is shinier bc it allows all the light to shine off of it. Source _URL_0_ | [
"Plain’s rocks have been very slightly altered, probably by thin films of water because they are softer and contain veins of light colored material that may be bromine compounds, as well as coatings or rinds. It is thought that small amounts of water may have gotten into cracks inducing mineralization processes.\n"... |
why are shows with fake laughter so succesful? | Laughter, like yawning, can be an "Infectious" reaction. We hear it, and there is often a compulsion to join in, and that in turn can trick some people into thinking something is funnier than it might have been if just dropped as a line on it's own. | [
"However Robert Hanks in \"The Independent\" said \"remarkable for its combination of very silly jokes and rather well-researched evolutionary theory. The cast is good. The plot of last night's episode was pleasantly absurdist, the jokes were commendably odd and wide-ranging [...] Somehow, though, it didn't quite g... |
why are truly random numbers significantly advantageous to pseudorandom numbers? | That part about selling random numbers online was a joke. Hardware RNGs are cheap, and having someone else generate your random numbers and send them over the internet would defeat the purpose of having secure RNG in the first place.
Good pseudo random generators (called cryptographically secure) produce a sequence of... | [
"A pseudorandom process produces predictable outcomes given information which is typically difficult to acquire; absent such information, pseudorandom sequences of numbers exhibit statistical randomness.\n",
"Pseudorandom number generators require tests as exclusive verifications for their \"randomness,\" as they... |
Russian colonialism in Africa? | While I'm certainly not qualified to answer anything in this subreddit, I would suggest looking into the story of the colony of [Sagallo.](_URL_0_) As far as I'm aware, this was Russia's only move in the scramble for Africa. Perhaps somebody more well versed could follow up on this? | [
"In 1889, a Russian adventurer, Nikolay Ivanovitch Achinov, tried to establish a Russian colony in Africa, Sagallo, situated on the Gulf of Tadjoura in present-day Djibouti. However this attempt angered the French, who dispatched two gunboats against the colony. After a brief resistance, the colony surrendered and ... |
what actually happens when you get frostbite if there is no chance of saving the body part? does the whole thing - including the bone - simply break off? | No, the bone doesn't break off. The flesh clings on, and rots, leading to a possibly fatal infection called gangrene. To prevent this, the flesh must be cut off. The protruding bone is typically then removed with a saw, so that the skin can be sutured shut. | [
"Frostbite is localized damage to skin and other tissues due to freezing. At or below , blood vessels close to the skin start to constrict, and blood is shunted away from the extremities. The same response may also be a result of exposure to high winds. This constriction helps to preserve core body temperature. In ... |
How common was it for people to have fleas in the European middle ages? | People did have a sense of hygiene in the Medieval Period, Doctors especially recognised the need for hygiene, this was definitely the case in Italy where doctors were more highly regarded than other countries at the time.
During the Black Plague in the 14th century, doctors in Italy argued that better sanitation was ... | [
"Fleas and Lice are a crust punk band from Groningen, Netherlands. Three of the members were originally part of Mushroom Attack, also from the Netherlands. Their records have been released by Skuld Releases in Europe, and Profane Existence Records and Rodent Popsicle Records in the United States. Since 1993, they ... |
how does novocaine work to numb tissue and how how/why does it wear off? | I can give you a very large and complex answer if you change your mind.
Novocaine hasn't been used in a long time. It's an eponym.
It's a sodium channel blocker. Meaning your local anesthetic gets in the way of pain signals thus blocking it. You also lose all sensation because it blocks normal signals too.
Source... | [
"Preliminary studies indicate that antibiotics and anticancer drugs may be encapsulated in electrospun nanofibers by adding the drug into the polymer solution prior to electrospinning. Surface-loaded nanofiber scaffolds are useful as adhesion barriers between internal organs and tissues post-surgery. Adhesion occur... |
Static electricity discharge | I would assume if you have the metal being sandblasted earthed, you wouldnt get shocked
| [
"Static electricity is an imbalance of electric charges within or on the surface of a material. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is named in contrast with current electricity, which flows through wires or other conductors an... |
How long will we see recessive human traits such as green eyes, red hair, and blue eyes? | Green and blue eyes are caused by both an intermediate and low (respectively) pigmentation of melanin in the iris, combined with a great deal of Rayleigh scattering. As such, I suspect that since it is not a simple, single-factor Mendelian genetics puzzle, this question will not be easily answerable.
[Wiki](_URL_0_) | [
"Mutagenesis experiments involving the Boreoeutherian ancestor to humans have shown that seven genetic mutations are linked to losing UV vision and gaining the blue light vision that most humans have today over the course of millions of years. These mutations: F46T, F49L, T52F, F86L, T93P, A114G and S118T, include ... |
Do we send satellites to other planets to orbit and observe, and if we don't, why haven't we? | Currently orbiting **Mars** is the [Mars Reconnaissance Orbiter](_URL_4_), which has been used to relay signals from Mars rovers like Curiosity and in fact [snapped a picture of Curiosity's descent](_URL_0_) to the surface. The [Mars Global Surveyor](_URL_3_) and European [Mars Express](_URL_2_) are other missions sent... | [
"Other small natural objects in orbit around the Sun may enter orbit around Earth for a short amount of time, becoming temporary natural satellites. , the only confirmed example has been in Earth orbit during 2006 and 2007, though further instances are already predicted.\n",
"More than 1,000 unmanned missions hav... |
why do medieval hoods have a "tail"? | they were called liripipes. Most people believe it was just a fashion trend at the time, one that was capitalized by modern artists/video games/what have you whenever they want to make something look "medieval." There are a few manuscripts from around the fourteenth century in which people complain about how ridiculou... | [
"Historically, hoods were either similar to modern hoods, often forming part of a cloak or cape, or a separate form of headgear. Hoods with short capes, called chaperons in French, were extremely common in medieval Europe, and later evolved into big hats. Soft hoods were worn by men under hats. Hoods have also been... |
with no operator in sight how do railroad crossing activate? | It's called an induction loop. It's the same technology that detects when there's a car at a traffic light.
It's basically a magnetic sensor. When a train is on the track, it changes the magnetic field *enormously* at that spot, and that triggers the crossing alarms. | [
"Interlocking signals are controlled by human operators in a signal tower near the switches, not by the trains themselves. A train operator must use a punch box, which is located besides the cab window in the station closest to the interlocking, to notify the switch operator of which track the train needs to go to.... |
why do we use the current signal waves for wifi even though they can get disrupted by walls? is there a better solution, if so why aren't we using it? | I think there are 2 reasons for this. The first one is that you don't want your signal to be able to pass through walls indefinitely. The wifi signal can pass through a few walls before it gets too weak, which is fine for most houses. Imagine that they could pass through walls without losing signal though. You'd have i... | [
"Wireless systems have an advantage over wired systems in last mile applications in not requiring lines to be installed. However, they also have a disadvantage in that their unguided nature makes them more susceptible to unwanted noise and signals. Spectral reuse can therefore be limited.\n",
"Wi-Fi allows wirele... |
can you lock a door with a lockpick? | Yep. The same principle works, you just spin the lock the other direction once all the pins are lined up. In a tumbler lock anyway. | [
"A lock is a device that prevents access by those without a key or combination, generally by preventing one or more latches from being operated. Often accompanied by an escutcheon. Some doors, particularly older ones, will have a keyhole accompanying the lock.\n",
"A \"master keyed lock\" is a variation of the pi... |
What causes the difference in sound heard between a rumbling and a crackling lightning strike? | Several factors affect the sound of thunder, most of which have to do with the path that the sound takes from the lightning bolt to your ears.
A lightning bolt can be several kilometers long, so the thunder generated from the point nearest to you can reach you as much as 20-30 seconds before that from the point furthe... | [
"Because the electrostatic discharge of terrestrial lightning superheats the air to plasma temperatures along the length of the discharge channel in a short duration, kinetic theory dictates gaseous molecules undergo a rapid increase in pressure and thus expand outward from the lightning creating a shock wave audib... |
How can light put force on objects? | Could you elaborate on the sound a bit more? I find it very hard to believe that a flash or light could transfer enough momentum to a cymbal to make it sound. It could be more of a thermal effect, but even then that is unlikely.
The sound could have been the capacitor in the flash mechanism recharging.
Lets assume l... | [
"Light falling on conventional materials, with a positive index of refraction, exerts a positive pressure, meaning that it can push an object away from the light source. In contrast, illuminating negative index metamaterials should generate a negative pressure that pulls an object toward light.\n",
"Light exerts ... |
Is lead (Pb) "spent" uranium (U) ? | Uranium decays to something which decays to something etc. down to lead. In that sense you could call it that, but it's not a standard term.
Most lead was never uranium though. | [
"Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope U-235 than natural uranium. Natural uranium contains about 0.72% U-235, while the DU used by the U.S. Department of Defense contains 0.3% U-235 or less. Uses of DU take advanta... |
steroids? | At some point, we realized that men seem to be more muscular than women (just in general). As it turns out, there's a chemical called testosterone that's pretty important for male development. Among other things, testosterone makes it easier for the body to make certain proteins, including the ones in muscle. Anabolic ... | [
"Steroids is a monthly peer-reviewed scientific journal covering all aspects of steroid hormones. It was established in 1963 and is published by Elsevier. The editors-in-chief are R.B. Hochberg (Yale University) and W. Rosner (St. Luke's-Roosevelt Hospital Center). According to the \"Journal Citation Reports\", the... |
why do restaurants offer various types of bread before the main course if it serves only to full us up? wouldn't this in turn make them less money? | To my understanding, it's cheap, it makes the patron feel like they're getting something for free - which always feels good. In addition, it keeps the customer preoccupied while busy servers and kitchen staff work to fulfill other orders. You're less likely to complain about service if you have a basket of bread in fro... | [
"According to Australian food rescue pioneer OzHarvest, \"Bread is the cheapest commodity, it's so easy to keep churning out. For bakeries, if they want to make their shelves look full they have to keep making it\".\n",
"The consumer benefits, because freshly baked bread is available in markets where it may not h... |
what causes people to become less flexible? | Flexibility comes from our ligaments and tendons, the fibers that hold our muscles together and anchor them to our bones. Over time, they start to harden.
Your genes only care about you as long as you can reproduce. There's no incentive to maintain the body past a reproductive age, so we start to deteriorate. Presbyo... | [
"Laboratory measures of flexibility are consistent with how flexible people are in their actual lives. Flexibility measured in laboratory settings even predicted how flexible people will be in real life. More recently however, the validity of the AAQ has again been brought into question, primarily by inconsistent r... |
Why did the soviets cease development and production of the a43 tank? | There were multiple reasons the A-43/T-43 never made it past the prototype stage.
First, the Soviets apparently had problems developing the proposed power plant for the tank, a V-5 diesel. The delay required to get the problems worked out came at a time where over 1200 T-34s were being built per month.
Second, it wa... | [
"Soviet heavy tank production was constantly in danger of cancellation during the war, and only continued thanks to constant improvement and liberal doses of political interference. These vehicles required significantly more resources to produce than the T-34 medium tank, and were always outmatched by it in some si... |
How sure are scientists, that the causes of the "Medieval Warm Period" are negligible for the current global warming trend? | [Skeptical Science](_URL_1_) sums up the scientific arguments pretty well. The Medieval Warm Period was a localized warming, mainly in Europe, rather than a rise in global temperatures like we see now. Some of this was clarified pretty recently. Because of this, it doesn't offer much of a guide towards explaining the r... | [
"In a perspective commenting on MBH99, Wallace Smith Broecker argued that the Medieval Warm Period (MWP) was global. He attributed recent warming to a roughly 1500-year cycle which he suggested related to episodic changes in the Atlantic's conveyor circulation.\n",
"Notable periods of climate change in recorded h... |
why do some recipes call for melted butter? | Basically, when recipies call for softened butter, they use the creaming method; the sugar and butter are mixed together in such a way that the sugar cuts little air bubbles into the butter. These little bubbles can add some extra puff to the cookies.
If you melt the butter first, not only do you not have those air bu... | [
"Melted butter plays an important role in the preparation of sauces, most obviously in French cuisine. \"Beurre noisette\" (hazelnut butter) and \"Beurre noir\" (black butter) are sauces of melted butter cooked until the milk solids and sugars have turned golden or dark brown; they are often finished with an additi... |
why do guns that fire the same caliber of bullet have different muzzle velocities? | Bullets are accelerated by the expanding hot gasses behind the bullet. If your barrel is 3 inches long, the bullet leaves the barrel before all the gas is finished pushing on the bullet.
If your barrel is 5 feet long, the gas pushes all it can and then the bullet slows down due to friction in the barrel.
Somewhere in... | [
"With a simplistic approach to physics, recoil being directly proportional to \"muzzle velocity × bullet mass\" (due to conservation of momentum), the recoil of the .357 SIG is equal to or slightly less than that of the .40 S&W, and less than that of the full-power 10mm Auto loads or the original .357 Magnum, (see ... |
At what point in the digestive tract does the food you eat actually become poop? | When food is digested in your body, the intestines and the enzymes in your stomach get all the nutrients that they can out of the food. The excrement is just that last little bit of unusable matter. Hope that helps!
| [
"In most vertebrates, digestion is a four-stage process involving the main structures of the digestive tract, starting with ingestion, placing food into the mouth, and concluding with the excretion of undigested material through the anus. From the mouth, the food moves to the stomach, where as bolus it is broken do... |
Which over the counter (U.S.) painkiller has the optimal mix of effectiveness and safety? | Generally, yes, they vary quite a bit. For example, I cannot take ibuprofen, as it makes me throw up, and aspirin makes my stomach hurt. I can take acetaminophen. However, acetaminophen is not good for people with liver problems or heavy drinkers--for those people, other painkillers are safer. Aspirin is contraindic... | [
"Because of its extremely high potency, it is often used in surgery and post-operative pain management for patients that are heavily opioid dependent/opioid tolerant because of long term opiate use for chronic pain or illicit opiate use. Currently sufentanil is the strongest opioid painkiller available for use in h... |
What makes an entire forest grow like this? [picture inside] | Actually there's a [quite detailed explanation](_URL_0_) linked to in the German Wikipedia entry for it.
The short answer/translation is: Someone cut ([coppiced](_URL_1_)) them as Christmas trees in the 1960's, leaving one or two shoots. The shoots had to grow in a curved shape for the tree to remain balanced, while ... | [
"The original forest growth was maple, beech, hemlock, pine, birch, oak, and ash, with scores of other trees interspersed. Each variety prevailing in its favored locality, but not holding exclusive possession of a single farm. Where a second growth has been allowed to spring up, the soft woods in many cases have su... |
Is it possible to make bubbles a different shape, like make a bubble cube? | Bubbles adopt the shape that minimizes surface area. If there are no constraints, a free bubble will just form a sphere. You could fill a cubic wire frame with soap films and it would form some sort of [tesseract-looking shape](_URL_0_). | [
"The bubbles are formed by gases that are not removed in time during the manufacture or processing of the optical component. Since the pressure of the gas in each direction is evenly distributed, the shape of the bubble is usually spherical.\n",
"Bubbles can be effectively used to teach and explore a wide variety... |
The role of the Secretary of State in a President's cabinet, and how it has changed. [US Political History] | I think it's more a question of personality and perceptions of the office. The Secretary of State's role in the cabinet is foreign policy, and has been since its first occupant Thomas Jefferson.
However, it was long considered to be one of the most prestigious spots in the Federal government, next to the President. C... | [
"In 1946, in response to the rapid growth of the U.S. government's executive branch, the position of Assistant to the President of the United States was established, and charged with the affairs of the White House. Together with the Appointments Secretary the two took responsibility of most of the President's affai... |
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