question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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What's stopping a black hole from growing exponentially massive and destroying entire systems? | You might be interested in reading about [Sagittarius A*](_URL_0_), which is likely a colossal black hole at the center of our galaxy. It's thought to be about 12 light hours across, or about the size of the orbit of Neptune, and have a mass of about 5 million stars.
In fact, it's now commonly believe that every spi... | [
"The largest black holes in the universe are predicted to continue to grow. Larger black holes of up to (100 trillion) may form during the collapse of superclusters of galaxies. Even these would evaporate over a timescale of up to years. \n",
"If black holes evaporate under Hawking radiation, a solar mass black h... |
When they say that CERN achieved a heat record of ~5 trillion degrees, what does that actually mean/do? | Physicists often use "temperature" as a way of describing the average kinetic energy of a group of particles. The total energy involved is small, but the energy per particle is large, thus the temperature is large.
See [Wikipedia on the temperature of gasses](_URL_0_) for a somewhat relevant discussion. | [
"Gamow's prediction was a 5–10-kelvin black-body radiation temperature for the universe, after it cooled during the expansion. This was corroborated by Penzias and Wilson in 1965. Subsequent experiments arrived at a 2.7 kelvins temperature, corresponding to an age of the universe of 13.8 billion years after the Big... |
Can you give any information about this flag? | hi! Do consider x-posting this to /r/vexillology (the flag sub!) | [
"Some reference books give alternate versions of this flag, e.g. green with a white 6- or 8-pointed star, or green with a yellow star. None of the writers, however, cite any sources for their information.\n",
"This chapter, which describes about the national flag in detail, is the longest of the three chapters on... |
why do we grow out of things. | Because your tastes change as you get older and you learn more about the world and develop your social life. As you're exposed to more, better media, you start to realize how underdeveloped, uninteresting, and pandering a lot of children's media is. | [
"From an evolutionary perspective, creativity may be a result of the outcome of years of generating ideas. As ideas are continuously generated, the need to evolve produces a need for new ideas and developments. As a result, people have been creating and developing new, innovative, and creative ideas to build our pr... |
What property decides if a material can be a superconductor? | That is a really hard question to answer, mainly because there's several classes of superconductors and only for one of those we really understand all the details.
**Conventional** superconductors can be explained by [BCS Theory](_URL_0_). The gist of this theory is that 2 electrons interact with each other via deforma... | [
"On the other hand, there is a class of properties that are independent of the underlying material. For instance, all superconductors have \"exactly\" zero resistivity to low applied currents when there is no magnetic field present or if the applied field does not exceed a critical value. The existence of these \"u... |
my company has a wifi network for their employees to connect their "personal devices" to. can they see everything i do? | Connections that are end-to-end encrypted should be secure, assuming that your company isn't doing some sort of man-in-the-middle attack on your traffic.
"Man in the middle" would be that you try to get a secure connection to Site A, and a machine on the company network replies saying that it is Site A, and then you s... | [
"Wireless Internet service providers (WISPs) operate independently of mobile phone operators. WISPs typically employ low-cost IEEE 802.11 Wi-Fi radio systems to link up remote locations over great distances (Long-range Wi-Fi), but may use other higher-power radio communications systems as well.\n",
"BULLET::::- T... |
why aren't women allowed in the royal armoured corps? | They *can* join the Household Cavalry, Armoured Corps and Infantry regiments, they are just not allowed an active combat role.
I don't want to get into a debate about the reasons (can't be bothered to do this again) but remember that when people start to compare the physical fitness don't make the mistake of thinking ... | [
"Women are not allowed to have combat roles in the armed forces. According to a study carried out on this issue, a recommendation was made that female officers be excluded from induction in close combat arms. The study also held that a permanent commission could not be granted to female officers since they have nei... |
what gives soap operas that “low quality” feeling to them? is it the lighting? the dialogue? it’s very distinct, but hard to pin down. | Here are a couple that I always notice:
1. ) Audio quality. It makes a big difference to have someone's vocal audio sequestered from any foley that occurs in a scene, such as door closes, foot steps, clothing. Everything is normalized together, in the same input mic, so you hear EVERYTHING on the sound stage, includin... | [
"BULLET::::- The visual quality of a soap opera is usually lower than prime time U.S. television drama series due to the lower budgets and quicker production times. This is also because soap operas are recorded on videotape using a multi-camera setup, unlike primetime productions that are usually shot on film and f... |
Is there a drug linked to brain growth and development similar to how testosterone and FSH are linked to muscle growth and developent? | I'll edit this post to include some more hard science later, but check out /r/Nootropics
Nootropics are 'cognitive enhancing drugs', and may increase "intelligence". | [
"Sex steroids are not the only important influences upon hypothalamic development; in particular, pre-pubertal stress in early life (of rats) determines the capacity of the adult hypothalamus to respond to an acute stressor. Unlike gonadal steroid receptors, glucocorticoid receptors are very widespread throughout t... |
Manichaeism seems almost unique in being a former major international world religion that was rendered completely extinct without even small remnant populations. Why did it disappear so entirely? | What is a world religion? Roman paganism had millions of adherents, reduced to nothing. Ditto for the so-called mystery religions (besides possibly Christianity) that sprung out of: the cult of Isis, Mithraism, etc. Egyptian religion similarly had millions of adherents and died away. Aztec religion. Name a pre-Christi... | [
"Manichaeism's basic doctrine was that the world and all corporeal bodies were constructed from the substance of Satan, an idea that is fundamentally at odds with the Zoroastrian notion of a world that was created by God and that is all good, and any corruption of it is an effect of the bad. From what may be inferr... |
can every single thing a computer does be broken down into binary code? | ...the signals going to the monitor are in binary. Once inside the monitor, the signals get reinterpreted by the controller ciruits, in binary and determine the brightness of each color pixel, whose data is in binary. The pixels themselves are sent binary signals. The brightness of the pixel is controlled by how lon... | [
"A binary code represents text, computer processor instructions, or any other data using a two-symbol system. The two-symbol system used is often \"0\" and \"1\" from the binary number system. The binary code assigns a pattern of binary digits, also known as bits, to each character, instruction, etc. For example, a... |
How did Britain keep the value of its currency stable during its explosive growth in the 19th Century? [reposted because unanswered] | > Was it just the growth in supply of gold?
That was a big part of it. You had gold strikes in California, the Yukon, South Africa, Colorado, Australia, and so on, all increasing the money supply.
Another big part was the growth in the private creation of paper money by [commercial banks](_URL_0_), as well as by the... | [
"Throughout the period, expansionary monetary policy and easy credit also caused Britain's currency to depreciate and its exchange rate to fall. Concerned by this, the government appointed a committee to determine if convertibility should be resumed soon, regardless of whether the war was still going on. This Bulli... |
how do treadmills and other machines track your hearts bpm by those silver things on the handle? | The basic concept to be aware of here is what makes the heart beat.
Our heartbeat is driven by an electrical signal generated by a small group of cells (sometimes called pacemaker cells) located within our heart. The electric pulse generated by this group spreads through the heart, causing first one part, then the oth... | [
"Know Your Pulse - Since 2009 the AF Association has been campaigning for manual pulse checks to be included in all routine medical checkups carried out by the NHS in England. A manual pulse check is one of the easiest ways to detect a cardiac arrhythmia, which otherwise often goes untreated until a stroke or other... |
why is it illegal to not hire somebody because of their race/religion? | There are no quotas. No one is forced to hire minorities, you just can't discriminate against them. Given a choice between equal white and black candidates you can't choose on race. Many people prefer this because they wanted a society where merit was more important than race.
Even with non-discriminatory practices wh... | [
"In many countries laws are put into place to prevent organizations from engaging in discriminatory practices against protected classes when selecting individuals for jobs. In the United States, it is unlawful for private employers with 15 or more employees along with state and local government employers to discrim... |
why people trust crystal healing when there is no scientific evidence to support its claims? | The same as with most things people believe. There is a lot of anecdotal evidence, and when that evidence is put forward by a source someone already trusts - an actor, a family member, a community leader - the stories are believed without double-blind testing to back them up. | [
"There is no peer-reviewed scientific evidence that crystal healing has any effect; it is considered a pseudoscience. Alleged successes of crystal healing can be attributed to the placebo effect. Furthermore, there is no scientific basis for the concepts of \"chakras\", being \"blocked\", energy grids requiring gro... |
Why is it that we are losing helium into space, while hydrogen stays around? | Helium, a noble gas, is too light to be held under earths gravity. Hydrogen is lighter, and free hydrogen will also escape, however, it is also reactive, and unlike helium, is mostly bound up in compounds with other elements. Free hydrogen will still escape. | [
"All degassed helium is lost to space eventually, due to the average speed of helium exceeding the escape velocity for the Earth. Thus, it is assumed the helium content and ratios of Earth's atmosphere have remained essentially stable.\n",
"Atmospheric escape of hydrogen on Earth is due to Jeans escape (~10 - 40%... |
Are all elements produced in stars? | No.
Or at least there are some elements that we cannot possibly detect even if they were produced in stars. There are some elements which have extremely short half-lives. Which means that they can be created in laboratories, and there's a very short time within which these can be detected before they decay into other... | [
"The abundance of elements in the Solar System is in keeping with their origin from nucleosynthesis in the Big Bang and a number of progenitor supernova stars. Very abundant hydrogen and helium are products of the Big Bang, but the next three elements are rare since they had little time to form in the Big Bang and ... |
why do cars need transmissions but planes and boats don't? | Engines have a relatively narrow range of RPM where they perform efficiently.
Planes and boats propel themselves in a viscous atmosphere/fluid. As a result, plane and boat engines can operate in a fairly narrow range of RPM and still be effective. Within that narrow RPM range, the propeller/fan generates sufficient ... | [
"As modern ships' propellers are at their most efficient at the operating speed of most slow speed diesel engines, ships with these engines do not generally need gearboxes. Usually such propulsion systems consist of either one or two propeller shafts each with its own direct drive engine. Ships propelled by medium ... |
How fast does a torus need to rotate to simulate earth gravity? | You are right. A larger diameter requires a smaller angular speed. The formula is *g = omega*^(2)*r*, where:
* *g* is the Earth's gravity (9.8 m/s^(2))
* *r* is the radius of the ring
* *omega* is the angular speed of the ring. | [
"The cylinders rotate to provide artificial gravity on their inner surface. At the radius described by O'Neill, the habitats would have to rotate about twenty-eight times an hour to simulate a standard Earth gravity; an angular velocity of 2.8 degrees per second. Research on human factors in rotating reference fram... |
Why is it called "Missionary position"? Where does the term come from? | You may be interested in u/yodatsracist's recent 4-part answer to [I saw an article today claiming that the "missionary" position derives its name from Native Americans/Africans who saw missionaries having sex. How true is this?](_URL_0_) | [
"It is commonly believed that the term \"missionary position\" arose in connection with English-speaking Christian missionaries, who supposedly encouraged the sexual position in new converts in the colonial era. However, the term probably originated from Alfred Kinsey's \"Sexual Behavior in the Human Male\" through... |
Are bats the only carriers for Ebola that do not die from it? | *Technically*, we don't know for certain that bats even are the carriers, although they are the likeliest suspect. [This paper from 2005](_URL_1_) sampled a whole spread of animals to try and find a carrier, so that might help you on your search for different species.
Interestingly, [dogs can become infected](_URL_0_... | [
"Bats are transporters of many viruses that do not affect them due to their unusually high immune system efficiency. M. pusillus have been known to carry antibodies specific to Ebola. Mitochondrial analysis was conducted on multiple fruit bats following the Ebola viruses outbreak in 2014 and one of the bat species ... |
what are the rules in the music industry that govern how one artist’s song can be covered by another? | In the US you make and sell cover versions of other artists' songs \*without their permission\* as long as you do certain things, including paying them a fixed rate royalty. Here's a link with more information: [_URL_0_](_URL_0_)
& #x200B;
There is a slightly different process for cover bands that are preforming liv... | [
"Artists must have publishing rights for songs they release through the \"Rock Band\" Network, thus limiting the use of covers or remixes. However, Harmonix only seeks to gain non-exclusive licenses for songs, allowing artists to also have their songs used in other rhythm games. Artists will be able to remove songs... |
why do we have ear lobes ? | Where else would you put your 00 gauge plug? - WAIT! Don't answer that, I don't want to know.
There is no known biological function for the ear lobe. | [
"The ears either have (1) a hole in the center or (2) an ovaloid shape with an extended curl. In the former style, the upper outer ear is formed into an ovaloid shaped with a hole in the center while the lower outer ear is formed by a lobe. On the other hand, the latter style explains the formation of the upper out... |
Life in 1910, London | We've allowed this post, but you're unlikely to get a thorough answer. Questions like "were life conditions good?" and "were people happy?" are not really answerable: some people had a high standard of living and some did not; some people were happy most of the time and some were desperately unhappy, with every nuance ... | [
"A London Life is a novella by Henry James, first published in \"Scribner's Magazine\" in 1888. The plot revolves around a crumbling marriage and its impact on many other people, especially Laura Wing, the sister of the soon-to-be-divorced wife. Laura is a classic Jamesian \"central consciousness,\" whose reflectio... |
Why is strep throat, caused by a commensal bacteria, contagious? | Because there are different forms found in different people much like blood types, therefore it is fine for yourself to carry but not other people
The exact reason strep throat is contagious.
Because if a new type of streptococcus is found the body sends infection markers and can be potentially fatal if it's not your ... | [
"Strep throat is caused by group A β-hemolytic \"streptococcus\" (GAS or \"S. pyogenes\"). Other bacteria such as non–group A β-hemolytic \"streptococci\" and \"fusobacterium\" may also cause pharyngitis. It is spread by direct, close contact with an infected person; thus crowding, as may be found in the military a... |
could it be possible that a black hole in our universe turns out to be a big bang in some other universe? | [There's a Polish cosmologist who thinks this might be possible.](_URL_0_)
It's totally untestable, though. At least, for a very long time. | [
"The initial state of the universe, at the beginning of the Big Bang, is also predicted by modern theories to have been a singularity. In this case the universe did not collapse into a black hole, because currently-known calculations and density limits for gravitational collapse are usually based upon objects of re... |
How big is our solar system in non-planar directions (up & down rather than out) | blorg is on the right track except for two things:
1) The heliopause (and associated other surfaces between the solar wind and the interstellar medium [ISM]) is thought to be more comet shaped than spherical. The sun is moving through the ISM, and thus toward the nose it is more compressed, and in the opposite directi... | [
"The geocentric system is simpler, being smaller and involving few massive objects: that coordinate system defines its center as the center of mass of the Earth itself. The barycentric system can be loosely thought of as being centered on the Sun, but the Solar System is more complicated. Even the much smaller plan... |
In the early 19th century why did it take so long for major powers to adopt the rifle over the musket? | Rifles achieved their increased accuracy by taking a small lead ball (the bullet) and wrapping it in a wad of cloth (usually felt). The felt wad would then grip the spiral grooves of the bore which would in turn "spin" the bullet as it traveled down the barrel, this spin stabilized the ball as it traveled through the a... | [
"During the 1850s, in a technological revolution of major proportions, the rifle musket began to replace the relatively inaccurate smoothbore musket in ever-increasing numbers, both in Europe and America. This process, accelerated by the Civil War, ensured that the rifled shoulder weapon would be the basic weapon u... |
the difference between piston plane engines and car engines | if car engine breaks down, you putter to side of the road and call AAA.
& #x200B;
if your plane engine breaks down, you fall out of the sky and call FAA.
& #x200B;
if you maintained your car engine at same level of your plane engine, you'd be doing inspection every morning before leaving for work. oil changes... | [
"Aircraft design more strongly favors lower weight and air-cooled designs. Rotary engines were popular on aircraft until the end of World War I, but had serious stability and efficiency problems. Radial engines were popular until the end of World War II, until gas turbine engines largely replaced them. Modern prope... |
Has there ever been a mathematical "Piltdown Man"? That is, a mathematical theorem that was accepted as valid for many years, only to have a fatal flaw discovered much later? | Not to insult the folks here, but you could try x-posting over at /r/math. | [
"Victor Michael Jean-Marie Thébault (1882–1960) was a French mathematician best known for propounding three problems in geometry. The name Thébault's theorem is used by some authors to refer to the first of these problems and by others to refer to the third.\n",
"The unsolved problem stimulated the development of... |
How was FDR's decision to run for a third term received by the Democratic Party? By his 4th election was there "Roosevelt Fatigue"? | Roosevelt’s decision to run for a third term was heavily influenced by the foreign affairs of the time re: Germany and the struggle of the British to defend and fight back. The national sentiment towards isolationism, especially among politicians, ultimately convinced Roosevelt to seek a third term. He viewed this less... | [
"On July 2, H. L. Mencken declared that, by his observation, the party lacked confidence in both Roosevelt's ability to deliver a general election victory and his physical fitness for the office of president. He opined that the party had nominated the weakest candidate that had been presented before them. Mencken f... |
what keeps a panting dog from hyperventilating ? | Panting in dogs tends to be shallow breaths an they're not moving a ton of air, which prevents them from blowing off all their carbon dioxide (CO2) and getting respiratory alkalosis (high blood pH which causes an acid/base imbalance). But not always... dogs that are taking fast, deep breaths will suffer from the same h... | [
"Unlike dogs, panting is a rare occurrence in cats, except in warm weather environments. Some cats may pant in response to anxiety, fear or excitement. It can also be caused by play, exercise, or stress from things like car rides. However, if panting is excessive or the cat appears in distress, it may be a symptom ... |
Did the Union Jack ever have a red background with a blue central cross? | No. The Union Jack has only ever had a red cross (from the flag of England) and a blue background (from the flag of Scotland). Whoever coloured this image made an error. And whoever drew it too, for that matter. The British flag being lowered seems to be an illustration of the *current* Union Jack, which was adopted in... | [
"The Union Jack also appeared on both the 1910–1928 and 1928–1994 flags of South Africa. The 1910–1928 flag was a red ensign with the Union coat of arms in the fly. The 1928–1994 flag, based on the Prinsenvlag and commonly known as the \"oranje-blanje-blou\" (orange-white-blue), contained the Union Jack as part of ... |
why are we training so many kids to code? | We teach all kids history, it doesn't make them grow into historians. (It doesn't even grow many of them into history-aware people, kids forget most of what they learn or never gain much competence at it anyway.)
Additionally a lot of the cheaper overseas folk are sub-par programmers too. | [
"In the Tech Lab, children are introduced to coding by learning how to program a robot to complete a series of tasks, navigate mazes, and play games. Each activity is designed to promote creative problem-solving in novice programmers. More experienced coders can program robots to respond to sensor inputs and use lo... |
why is a sugary drink sticky when spilled, but an artificially sweetened one not? | Artificial sweeteners are much more concentrated. So, when they dry out, there is less leftover. | [
"A variety of beverages call for sweetening to offset the tartness of some juices used in the drink recipes. Granulated sugar does not dissolve easily in cold drinks or ethyl alcohol. Since the following syrups are liquids, they are easily mixed with other liquids in mixed drinks, making them superior alternatives ... |
Benedict Arnold is regarded as the biggest traitor of the American Revolution. I've heard that he was treated poorly by America beforehand though. What's his story? | [Here's a previous thread](_URL_0_) with a response by /u/zuzahin that goes in-depth into Arnold's story and motivations. | [
"Benedict Arnold (June 14, 1801) was an American military officer who served as a general during the American Revolutionary War, fighting for the American Continental Army before defecting to the British in 1780. George Washington had given him his fullest trust and placed him in command of the fortifications at We... |
why are puns generally frowned upon (albeit humorously)? | because groaning and rolling your eyes is the response we hope for when we make a terrible pun. It's basically applause | [
"Puns are a common source of humour in jokes and comedy shows. They are often used in the punch line of a joke, where they typically give a humorous meaning to a rather perplexing story. These are also known as feghoots. The following example comes from the movie \"\", though the punchline stems from far older Vaud... |
why does it seem that most movies have a "happy" ending? | Because most people like happy endings. | [
"A lot of people, it just kicks 'em right in the head. This is a strange thing to say, but 30 or 40 years ago, I don't think the ending would have been quite so surprising. Because, even though Hollywood is built upon the convention of happy endings, in the old days there was always the 20 percent, or something lik... |
How popular were the Odyssey and the Iliad in Ancient and Classical Greece? | The Homeric poems seem to have been composed in the early-to-mid-7th century BCE, ca. 670-650 in the case of the *Iliad*, but though the stories of the Trojan War and of Odysseus' return were popular throughout the Greek and Etruscan worlds from a very early date, the poems themselves seem to have had only limited diss... | [
"The Odyssey (; \"Odýsseia\", in Classical Attic) is one of two major ancient Greek epic poems attributed to Homer. It is, in part, a sequel to the \"Iliad\", the other Homeric epic. The \"Odyssey\" is fundamental to the modern Western canon; it is the second-oldest extant work of Western literature, while the \"Il... |
Could someone clear this whole thing up? (When smoking from a bowl made of aluminum, can aluminum enter the lungs?) | You don't have to melt the Al to get it into the lungs, you just have to mince it fine enough to get it suspended in the air. I can see this happening with heating Al foil, especially repeated heating.
I don't know exactly how they are using it in the linked discussion, though, and I don't know the exact chemistry in... | [
"Inhalation of aluminum arsenide may cause acute irritation to the respiratory system. It may also cause chronic arsenic poisoning, ulceration of the nasal septum, liver damage and cancer/diseases of the blood, kidneys and nervous system. Aluminum arsenide is poisonous if ingested and may cause gastrointestinal and... |
how do floors get mopped, garbage cans get emptied, plumbing get repaired etc. in top secret areas? are there janitors with high level security clearance? | Areas like that have "clean desk" policies where everything has to be secured in locked drawers when you are not at your desk. If it is somewhere with constant activities then the people there take their trash to somewhere outside the room where it gets collected. | [
"Most municipal building codes mandate that drain plumbing increase in diameter as it moves closer to the municipal sewer system. I.E., most kitchen sinks evacuate water with a -inch drain pipe, which feeds into a larger 4-inch drain pipe on the main plumbing stack before heading to a septic tank or to the city sew... |
if you are able to look at somebody's reflection, this person must also be able to look at yours. does this concept apply always? | If the other person is blind. | [
"BULLET::::- Level 3: Identification. This stage is characterized by the new ability to identify self: an individual can now see that what's in the mirror is not another person but actually them. It is seen when a child, instead of referring to the mirror while referring to themselves, refers to themselves while lo... |
what happens to clinically insane people after committing crimes that if a non-insane person did, they would receive the death penalty? | There's a concept in criminal law, that requires that the person understand what they did was wrong. This concept can be directly traced back to Roman legal codes (though like many Roman concepts, they borrowed it from a [Greek thinker](_URL_1_)). It's not true for certain type of crimes (crimes stemming from crimina... | [
"Insane individuals are not punished for their crimes. During the reign of Henry VIII, however, it was enacted that in the cases of high treason, an idiot could be tried in his absence as if he were perfectly sane. In the reign of Mary I, this statute was repealed. Today there are powers to send insane defendants t... |
Do doppelgängers have extremely similar DNA like siblings or twins do? Or do they appear unrelated when taking a DNA test? | If you are asking whether people that look superficially the same as you would show up as related to you if they took a DNA test, then no. These types of genetic testing look primarily at so called junk DNA, the ~98% of you DNA that is not actively involved in how your body is created, so any similarities between peopl... | [
"Each person’s DNA is unique to them to the slight exception of identical (monozygotic and monospermotic) twins, who start out from the identical genetic line of DNA but during the twinning event have incredibly small mutations which can be detected now (for all intents and purposes, compared to all other humans an... |
how are there enough cows to supply the over 15k macdonalds and burger kings in u.s. | First, a single cow produces an awful lot of hamburgers. A grown steer produces about 500 pounds of beef, which is 2000 quarter-pound hambugers.
Second, there are enormous herds of cattle on ranches in the rural parts of the US, which you generally don't see because they're not along highways, but the US is enormous ... | [
"Cow–calf operations are widespread throughout the United States. A 1997 census found that this sector of the U.S. beef market produced over $40.5 billion. As of 2007 there were more than 765,000 cow–calf operators in the country, mostly concentrated in the Western and Southeastern U.S. states.\n",
"Beef producti... |
why do my hands feel weak after i watch doctors taking blood. | Likely because some part of the process makes you anxious and you experience a mini fight-or-flight reaction of blood being drained from your extremities to be pumped into things your body deems more important in the moment. Possibly resulting in your hands even becoming totally numb.
Source: Am deathly afraid of nee... | [
"Men were generally partially sedated with chloroform or alcohol before surgery. When properly done, the patient would feel no pain during their surgery, but would not be totally unconscious. Stonewall Jackson, for example, recalled the sound of the saw cutting through the bone of his arm, but recalled no pain. Inf... |
if black absorbs all colors on the visible spectrum, then how are there glossy black finishes that reflect light | Pure black would absorb all colours, however pure black doesn't exist. Glossy black reflects some of the light.
There is the nanotubes based black called Vantablack which reflects only 0.04% of the light. And that is the blackest black we have at this moment: People who see it for the first time go from "There is an e... | [
"Absorption of light is contrasted by transmission, reflection and diffusion, where the light is only redirected, causing objects to appear transparent, reflective or white respectively. A material is said to be black if most incoming light is absorbed equally in the material. Light (electromagnetic radiation in th... |
Can chivalry in the Middle ages be seen as an attempt to rein in the violence of the warrior classes? | A partial answer: a part of the idea of 'chivalry' in western Europe came from the [Peace and Truce of God](_URL_0_) a movement traced to the tenth century that resulted in quite a few proclamations by both religious and secular leaders. It was an attempt to govern internal violence, setting aside days of the year on ... | [
"Chivalry was developed in the north of France around the mid-12th century but adopted its structure in a European context. New social status, new military techniques, and new literary topics adhered to a new character known as the knight and his ethos called chivalry. A regulation in the chivalric codes includes t... |
what is going through my cat's head when he runs back and forth seemingly aimlessly? | Although there are a bunch of factors to consider, (sterilization, age, etc) if I had to make a personal guess, I'd say he has a natural instinct to prowl and hunt like in the wild and since he can't exactly do those things, he just aimlessly runs. | [
"In the cabin earlier, Tom chases Jerry in circles, until the mouse breaks off and runs directly near the open door outside, as Tom does also. Unbeknownst to the cat, he got too fast, and in a similar fashion to Wile E. Coyote and the Road Runner, he is far off the cliff, with Jerry still on the ground, safe. Tom t... |
In physics, why is the formula to calculate force F=ma instead of F=mv (mass x velocity)? | The problem is that you are not calculating an impact force correctly. The equation **F** = m**a** tells you the net force on an object. But the equation does not tell you directly the impact force of one object on another when they crash.
For instance, if an object of mass *M* traveling at speed *V* just before impac... | [
"where F is the force on mass 1 due to its interactions with mass 2, and F is the force on mass 2 due to its interactions with mass 1. The two dots on top of the x position vectors denote their second derivative with respect to time, or their acceleration vectors.\n",
"Therefore, the Newtonian definition of mass ... |
What stopped Nixon's push for Universal Healthcare? | Politics, plain and simple.
Until the end of his life Sen. Edward Kennedy said his greatest regret during his political career was turning down President Nixon's deal on healthcare.
[This column] (_URL_1_) from 2009 and [this one] (_URL_0_) from 2012 do a good job explaining the plan and the dynamics of the 1970s tha... | [
"In 1971, Nixon proposed health insurance reform—a private health insurance employer mandate, federalization of Medicaid for poor families with dependent minor children, and support for health maintenance organizations (HMOs). A limited HMO bill was enacted in 1973. In 1974, Nixon proposed more comprehensive health... |
how is liquid nitrogen kept cold? can it be kept in a bottle for a long period and still be cold? | LN2 is stored in dewar's for smaller amounts or in cryogenic tanks for larger quantities. Dewar's are just high efficiency thermos tanks usually with a vented lid. Why the vent? Because no thermos is perfect at retaining temperature, so as temp goes up, the volume increases and there is a phase change from liquid to ga... | [
"Liquid nitrogen is a cryogenic fluid that can cause rapid freezing on contact with living tissue. When appropriately insulated from ambient heat, liquid nitrogen can be stored and transported, for example in vacuum flasks. The temperature is held constant at 77 K by slow boiling of the liquid, resulting in the evo... |
how does left-cardiac hypertrophy lead to cardiac arrhythmias? | With left-sided hypertrophic cardiomyopathy, the left ventricle is very muscular and that leaves little room for blood to fill up in it between beats. As a result, you can get blood backing up into the left atrium. This stretching can cause electrical signals to get "messed up" (simple way to put it), resulting in the ... | [
"Hypertensive heart disease is the result of structural and functional adaptations leading to left ventricular hypertrophy, diastolic dysfunction, CHF, abnormalities of blood flow due to atherosclerotic coronary artery disease and microvascular disease, and cardiac arrhythmias. Individuals with left ventricular hyp... |
would there be any temperature difference if the speed of the light were slower? | I'm not sure I can ELI5 this, but i'll just try and explain it anyway. I'm not really sure what the best answer, but my best guess is that it depends on what other physical constants changed. Assuming that everything was held constant and you just halve c, going with the [plank einstein relation](_URL_0_) E=c/wavelengt... | [
"In the theory, the one-way speed of light is principally only equal to the two-way speed in the aether frame, though not in other frames due to the motion of the observer through the aether. However, the difference between the one-way and two-way speeds of light can never be observed due to the action of the aethe... |
why are x-rays emitted through high powered lights, and just how dangerous could it be with prolonged exposure? | Those aren't actually stage lights; they're the CRT picture tubes from a [rear projection TV](_URL_0_).
CRTs work by accelerating a beam of electrons in a vacuum tube to high energy, and letting the beam hit the phosphor-coated inner surface of the screen. Some of the energy excites atoms in the phosphorecent coating... | [
"Lead is the most common shield against X-rays because of its high density (11340 kg/m), stopping power, ease of installation and low cost. The maximum range of a high-energy photon such as an X-ray in matter is infinite; at every point in the matter traversed by the photon, there is a probability of interaction. T... |
what process has happened over the years that makes things i found as a child hilarious to me then but now not finding them as humorous. | You've developed more sophisticated tastes. Maybe not much more sophisticated, but still, at least a little. You've seen things that are far funnier than simple rude jokes or silly cartoons, and you've also seen so many rude jokes that the idea has gotten old. | [
"The cognitive component of humor is clearly exemplified during the years of childhood, which is characterized by evolving cognitive structures. As a child advances from one degree of cognition to the next, what is considered humorous and what is not should also manifest a meaningful progression. Understanding any ... |
How much air do various plants need to live relative to humans? | The short answer is very little. You can keep a [plant in a glass jar]( _URL_0_) forever.
In principle a plant could run out of CO2, but in practice a plant will survive indefinitely in a sealed jar with a bit of soil because bacteria and nematodes tend to breathe in the O2 and exhale CO2. Plants also like to have oxy... | [
"Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air content and atmospheric pressure vary at different layers, and air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in Earth's t... |
What were the average prices of firearms in the 1890 era american west? | I would suggest finding a period Sears Roebuck catalogue. Sears Roebuck was the Amazon of its day, and sold everything from clothing to medicines to firearms by mail-order. | [
"The Colt 1860 cost approximately $20 per revolver. This was rather expensive during the 1860s, both for the United States Army and private citizens. Colt had been criticized for this high price, and by 1865 the revolver was reduced to $14.50.\n",
"Depending upon where one resided, $25 could purchase an acre of l... |
hpv -- so there's an std that basically everyone has and it's benign except when it isn't? | I don't want to tell you whether or not to worry about HPV, but here's what I know about it. There are several different strains. Some of them cause warts, some of them don't. The ones that don't cause warts can sometimes turn cells cancerous, but generally don't have any other noticeable side effects. There's a vaccin... | [
"HPV (Human papillomavirus) is the most common STI among teens (as well as adults). In a CDC study, 18% of teen girls were infected with HPV. Another study found that HPV infections account for about half of STIs detected among 15- to 24-year-olds each year. While HPV infections may not cause any disease and is oft... |
why did the dea decide to make cbd a schedule 1 narcotic? | Because there is a long history of pharmaceutical companies lobbying to have anything that might take some of their money made illegal. CBD oil is making headlines and deserves to be researched. By lobbying to have it made schedule I, there will be little to no research done in the U.S. ensuring that we will have to bu... | [
"While engaged in scheduling debates in the United States, the DEA also pushed for international scheduling. In 1985 the World Health Organization's Expert Committee on Drug Dependence recommended that MDMA be placed in Schedule I of the 1971 United Nations Convention on Psychotropic Substances. The committee made ... |
A (probably) dumb question about dimensions... | Absolutely. The [Klein bottle](_URL_0_) is one such example. | [
"The issue of dimension still matters to geometry as many classic questions still lack complete answers. For instance, many open problems in topology depend on the dimension of an object for the result. In physics, dimensions 3 of space and 4 of space-time are special cases in geometric topology, and dimensions 10 ... |
Historians, can you help me identify this money found in my granddad's WWII warchest? | These are some interesting but commonly found banknotes.
From top to bottom, left to right:
10 000 German Mark, 1920's Weimar Republic/Germany.
1 Pound - Japanese Occupation Currency for Oceania.
10 Pesos - Japanese Occupation Currency for the Philippines.
5 Pesos - Japanese Occupation Currency for the Philippines... | [
"BULLET::::- 1916-1920: \"PNB issued notes\". This note is never officially issued by the Philippine National Bank. 10,000 pieces were captured and issued during World War II by the Japanese. The others were looted by Moros in the Province of Mindanao who sold them at tenth of their face value.\n",
"The money fro... |
When the Germans were attacking Russia, and winter began, why didnt the Germans simply not take Russian clothing available on site? | The Soviets implemented a "scorched earth" policy designed to deprive the occupying Germans of anything and everything they might use to sustain themselves. This included burning down all usable buildings and their contents, killing any livestock that could not be brought east, poisoning wells and food, destroying mach... | [
"Early in the war, this consisted of heavy wool greatcoats (a similar pattern was issued to East German border guards until 1989). They had silver dimpled buttons that did not reflect the light and were sometimes painted green to provide further camouflage. Following Hitler's invasion of the USSR, the Germans found... |
What did Thomas Jefferson think of the Haitian Revolution? | In Thomas Jefferson's letter to Lafayette in 1791, he wrote about the American, French, and Haitian revolutions. He praised the French for "exterminating the monster aristocracy, & pulling out the teeth & fangs of it’s associate monarchy." However it is clear that he does not see the plight of the Haitians in the s... | [
"That year and once the Haitians declared independence in 1804, President Jefferson had to deal with strong hostility to the new nation by his southern-dominated Congress. He shared planters' fears that the success of Haiti would encourage similar slave rebellions and widespread violence in the South. Historian Tim... |
why hasnt a large group of people filed a class action suite against verizon or comcast | Many service providers in the US, including Comcast, have clauses in their user agreements which actually forbid customers from engaging in class-action lawsuits against the company. In fact, many of these user agreements prevent you from taking any legal action and mandate that all disputes (that can't be resolved dir... | [
"In 2007, Free Press, Public Knowledge, and the Federal Communications Commission filed a complaint against Comcast's Internet service. Several subscribers claimed that the company was interfering with their use of peer-to-peer networking applications. The Commission stated that it had jurisdiction over Comcast's n... |
why don't we have nintendo wii styled controls for a computer instead of the conventional mouse? | Because The wii mote is very imprecise for clicking. The ergonomics don't really work well for the complexities of computers. | [
"Because the Nintendo DS and Wii lack the dual analog joysticks that were used for control in the original game, the controls for \"Skate It\" were redesigned to take advantage of each platform's respective control methods. For example, the Wii version utilizes the motion sensing of the Wii Remote to control the pl... |
what is a typical career path taken to become a us ambassadors? | You can be anything you want! You just have to earn a lot of money. Then you donate it to a political party, and use that donation as leverage to get the position! | [
"Since the late 20th century, high-profile ambassadorships typically are selected by the White House and go to prominent political or financial supporters of the president. These amateurs are mostly sent to Western Europe or nations with strong economic ties to the U.S. Professional career ambassadors move up throu... |
what do pets think about all day? they must get bored. | Some do which is sometimes why bored dogs for instance destroy furniture | [
"As pets, they have been reported to eat mealworms, corn, melon, crickets, waxworms, tomatoes, cooked eggs, fruit, and even moist dog food. They can be shy about being watched while eating, and may stop and stare back motionless if this happens.\n",
"Happiest when working alongside a hunter, the Drent enjoys the ... |
excess reserves | > Watched Janet Yellen's testimony to congress last week.
For those of who do not want to use up all of our bandwidth, or week-end time, watching 6 hours of very boring you-tube, could you point us to the part that you are talking about? | [
"Abundance debentures are usually long-term investments which investors should expect to hold for the full 20 years. Although Abundance facilitates a process for debentures to be bought and sold before the end of their life, there is no guarantee that this can be done, or what the value will be. However, 2015 saw A... |
how can gov officials get away with giving seemingly classified information to news outlets? | > The official was not authorized to speak publicly on the subject
That is not the same thing and does not imply that they gave out classified information. What it means is that the employee was not designated as the public spokesperson for the organization. The information they are giving is not secret, but not the... | [
"Other critics have cited that there are some documents and data that need to be legitimately kept secret or discreet, and are worried that there is nothing to prevent the officials involved in a search from disclosing this sensitive data. They give examples of trade secrets, acquisition plans, plans for a new prod... |
why don’t you bleed out when you get an injection? | There is about 50 processes that occur to act together to clot your blood and plug the hole.
Some people could bleed out, they are called haemophiliacs, and their blood clotting system malfunctions in one way or another.
Bonus fun fact for you, if you take too many blood thinners, you can bleed out through your skin, d... | [
"The drugs are not mixed externally because that can cause them to precipitate. Also, a sequential injection is key to achieve the desired effects in the appropriate order: administration of the pentobarbital essentially renders the person unconscious; the infusion of the pancuronium bromide induces complete paraly... |
how does property line surveying work? | Property lines is often described using features in the terrain and not necessarily coordinates. And even if there is coordinates they may not have been measured with high accuracy, using old datum or the terrain might have changed. So a surveyor is walking around trying to make sense of the previous descriptions of th... | [
"In the United States, a plat ( or ) (plan or cadastral map) is a map, drawn to scale, showing the divisions of a piece of land. United States General Land Office surveyors drafted township plats of Public Lands Surveys to show the distance and bearing between section corners, sometimes including topographic or veg... |
Isn't it somehow obvious that mathematics don't work with infinite values? | Hidden inside your question is another very philosophically deep question: how does math work? As philosophers and mathematicians have concluded over the last few millienia, mathematics "works" by establishing a set of ground rules (called "axioms") and deducing consequences based on these rules.
Many of the currently... | [
"The authors argue that mathematics goes far beyond this very elementary level due to a large number of metaphorical constructions. For example, the Pythagorean position that all is number, and the associated crisis of confidence that came about with the discovery of the irrationality of the square root of two, ari... |
why do computers need screen savers but not tvs? | Because of [screen burn-in](_URL_0_).
If you let an old CRT screen display the same image for a longer period of time, that image can be permanently burnt into the screen. (check the link for examples.)
On TVs this wasn't a huge problem since TVs don't tend to show a lot of static images for long periods of time. Alt... | [
"Most modern computer screens are LCDs. To provide an image on a screen, LCD technology emits light from the screen towards the reader. This makes reading this screen harder than reading a printed sheet of paper where a reader will see the image because it reflects light. For this reason some people argue that a co... |
Why did China move to simplified characters instead of the traditional ones? | Short version: because traditional characters, while they make more sense while learning them, are a pain in the ass to write and look very intimidating. The stated benefit was that more people would become literate, which happened (for various reasons)
Longer version deals with Mao's apparent desire to replicate the ... | [
"The nature of Chinese characters makes it very easy to produce allographs (variants) for many characters, and there have been many efforts at orthographical standardization throughout history. In recent times, the widespread usage of the characters in several nations has prevented any particular system becoming un... |
Is there any evidence or possibility of truth to the theory that Psilocybin Mushrooms Contributed to Human Evolution? | No. It's a fun theory to entertain if you do a lot of drugs, but that's not how evolution (at this stage) works. Basically, evolution comes from mutations that are passed down through heredity. In other words, even if you gained a higher level of consciousness through pscilocybin mushrooms, this trait wouldn't be passe... | [
"Therefore, according to McKenna, access to and ingestion of mushrooms was an evolutionary advantage to humans' omnivorous hunter-gatherer ancestors, also providing humanities first religious impulse. He believed that psilocybin mushrooms were the \"evolutionary catalyst\" from which language, projective imaginatio... |
why is the proportion of left-handed people so small in comparison to right-handed people? shouldn't it be closer to 50:50 than the 10:90 ratio we see today? | Once humans starting using tools, handedness started to matter. A left handed person would be a disadvantage using tools make for right handed people.
On the other hand, with weapons, being left handed could be an advantage, if everyone was used to fighting right handed people. So there would be an evolutionary reas... | [
"However, more recently, in a 2014 study published by the National Bureau of Economic Research, Harvard economist Joshua Goodman finds that left-handed people earn 10 to 12 percent less over the course of their lives than right-handed people. Goodman attributes this disparity to higher rates of emotional and behavi... |
Can tungsten survive lava? | Tungsten **melts** at 3422°C (it boils at a much higher temperature). Pāhoehoe is one of the hotter types of lava, at about 1200°C.
So nothing would happen. It would get hot, but not melt. There are plenty of elements/metals that have melting temperatures hotter than 1200°C, like titanium, platinum, etc. | [
"Because tungsten is a rare metal and its compounds are generally inert, the effects of tungsten on the environment are limited. The abundance of tungsten in the Earth's crust is thought to be about 1.5 parts per million. It is one of the more rare elements.\n",
"A hard, rare metal under standard conditions when ... |
ferrofluid carrier fluid? | Did you make the carrier fluid yourself?
What was it already made out of?
A quick perusal of google suggests it's most commonly made with Kerosene and Oleic acid. | [
"The difference between ferrofluids and magnetorheological fluids (MR fluids) is the size of the particles. The particles in a ferrofluid primarily consist of nanoparticles which are suspended by Brownian motion and generally will not settle under normal conditions. MR fluid particles primarily consist of micrometr... |
how can an mri show the side of the body if the person is lying on their back? | It scans all around you, not just from one direction.
[MRI machine](_URL_0_). See how it is round and surrounds your entires body? | [
"Magnetic resonance imaging (MRI) may also be performed to assess the degree of certain anomalies such as abdominal wall and pericardial defects. An MRI uses a magnetic field and radio waves to produce cross-sectional images of particular organs and bodily tissues.\n",
"BULLET::::- Magnetic resonance imaging (MRI... |
how is digesting liquids possible? | Digesting is just breaking down things into small things, then breaking those down into tiny things so you can absorb them. You break proteins down into little amino acid blocks, break down carbs into small pieces, and break down fats into little fatty acids. Your body absorbs those, along with a lot of the water you... | [
"Water and saliva enter through the rumen to form a liquid pool. Liquid will ultimately escape from the reticulorumen from absorption through the wall, or through passing through the reticulo-omosal orifice, as digesta does. However, since liquid cannot be trapped in the mat as digesta can, liquid passes through th... |
Why was human anatomy poorly drawn in ancient works of art? | Not a professional historian, but I have read much on this on my own. Really the question here is fundamentally about the purpose of representational art.
In many cultures, paintings were not meant to be interpreted at face value, but rather as symbols. Anatomy is rather irrelevant when a culture simply uses painting ... | [
"Anatomy has served the visual arts since Ancient Greek times, when the 5th century BC sculptor Polykleitos wrote his \"Canon\" on the ideal proportions of the male nude. In the Italian Renaissance, artists from Piero della Francesca (c. 1415–1492) onwards, including Leonardo da Vinci (1452–1519) and his collaborat... |
what is technical the difference between a thread and an async-operation? | A thread is when you ask the operating system to start running another part of the program at the same time. If there are more parts running than CPU cores, the operating system will switch between them. Threads have a bunch of features (like separate stacks) that make them relatively "expensive". A program shouldn't h... | [
"The AN thread is a particular type of fitting used to connect flexible hoses and rigid metal tubing that carry fluid. It is a US military-derived specification that dates back to World War II and stems from a joint standard agreed upon by the Army and Navy, hence AN.\n",
"Addresses in the thread are the addresse... |
What started the European explorers craze that got them discovering the new world and Asia? | Money, prestige, and the struggle for dominance over rival nations. The usual suspects.
It started with Portuguese attempts to corner the spice trade to and from the East Indies by getting ships around Africa (to circumvent the Ottoman control of the ancient overland routes), which was made more complicated by the fa... | [
"With the Age of Discovery starting in the 15th century, Europeans explored the world by ocean, searching for particular trade goods, humans to enslave, and trading locations and ports. The most desired trading goods were gold, silver and spices. Columbus did not reach Asia but rather found what was to the European... |
investing: buying stocks, selling stocks. eh? | A stock is a piece of the company. If the company issues 1000 stocks, and you own 100 stocks, you essentially own 10% of the company.
The main reason for buying stocks is investment. If the company makes a profit, the company is worth more, so your share of the company is worth more. The company may also pay out divid... | [
"In the book, Fisher says that because the stock market is a discounter of all widely known information, the only way to make, on average, winning market bets is knowing something most others don’t. The book claims investing should be treated as a science, not a craft, and details a methodology for testing beliefs ... |
why does a yawn filter out any deep bass sounds? | The inner ear is normally sealed, air can’t get in or out. However there is a tube connecting it to the throat so that pressure can be equalised. When you yawn these tubes open. The same thing happens when you swallow and is why when your ears ‘pop’ , like in a plane, swallowing or yawning can fix it. It equalises the ... | [
"During a yawn, the tensor tympani muscle in the middle ear contracts, creating a rumbling noise from within the head. Yawning is sometimes accompanied, in humans and other animals, by an instinctive act of stretching several parts of the body, including arms, neck, shoulders and back.\n",
"The most common and ef... |
If fusion naturally occurs in stars, does fission occur naturally anywhere or only under manmade conditions? | A few nuclei, including some uranium isotopes, fission spontaneously. However this process is very rare. Most fission processes are induced by neutrons, which requires a large assemblage of radioactive and fissile material, and the right geological environment. This happened naturally at least once in the Earth's hi... | [
"Fission occurs naturally because each event gives off more than one neutron capable of producing additional fission events. Fusion, at least in D-T fuel, gives off only a single neutron, and that neutron is not capable of producing more fusion events. When that neutron strikes fissile material in the blanket, one ... |
What natural disaster significantly changed the course of history? | The [Lisbon earthquake](_URL_0_) of 1755 had a profound effect on enlightenment philosophy. All the churches were destroyed and a huge number of people killed on All Saints Day. This led an entire generation of influential philosophers, including Voltaire and Kant, to question the existence or benevolence of God. | [
"Throughout history, seismic events have at times caused submergence of human settlements. The remains of such catastrophes exist all over the world, and sites such as Alexandria and Port Royal now form important archaeological sites. As with shipwrecks, archaeological research can follow multiple themes, including... |
how do photographers who print a lot of tourist photos make a profit if not everything they printed is sold? how does their business model work? | Selling 1 photo pays for a LOT of unsold ones and people are more likely to buy something they can physically see in front of them then on a screen and then wait for it to be printed. | [
"Most photographers allow clients to purchase additional prints for themselves or their families. Many photographers now provide online sales either through galleries located on their own websites or through partnerships with other vendors. Those vendors typically host the images and provide the back end sales mech... |
How did people precisely control the temperature of ovens for baking at specific temperatures? | A bake oven is a very big pile of masonry. Get all that thermal mass up to temperature, and it will fluctuate fairly little, and occasional stoking with a little wood can keep it hot. This is why baking was commonly done either by bakers, all day/night long, or by housewives one day a week: once the oven was hot, yo... | [
"Common oven temperatures (such as terms: cool oven, very slow oven, slow oven, moderate oven, hot oven, fast oven, etc.) are set to control the effects of baking in an oven, for various lengths of time.\n",
"Before ovens had thermometers or thermostats, these standard words were used by cooks and cookbooks to de... |
pcr's (polymer chain reactions) | So it's been a while since I've done it but here goes : Think of DNA like a zipper. Pull the 2 sides apart and then cut the 2 single strands into chunks. With spare zipper teeth (ACTG) you can build 2 new strands, zip it back together and now you have 2 full zippers. | [
"The polymerase chain reaction (PCR) is a biochemical technology in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence.\n",
"The polymerase chain reaction (PCR) is a biochemistry and mo... |
how do news agencies decide what is a national story? | Great question. The short version is that the news outlets have an editorial meeting every day or every shift to discuss ideas and assign reporting staff to the stories. Many stories come from press releases or public tips. Many more come from routine events, like a city council meeting, a parade, or a local business ... | [
"The major news agencies generally prepare hard news stories and feature articles that can be used by other news organizations with little or no modification, and then sell them to other news organizations. They provide these articles in bulk electronically through wire services (originally they used telegraphy; to... |
What would a tub full of viruses look like? | Hey there! I work with viruses, and this is what I can tell you:
When we infect cells, we use vials of virus stockseed, which, depending on which virus you're working with, is essentially a purified suspension of virus that's been frozen and stored until it's needed for use. It's not 100% pure virus, which would be... | [
"Viruses display a wide diversity of shapes and sizes, called \"morphologies\". In general, viruses are much smaller than bacteria. Most viruses that have been studied have a diameter between 20 and 300 nanometres. Some filoviruses have a total length of up to 1400 nm; their diameters are only about 80 nm. Most vir... |
if websites like youtube can shorten their url for "sharing" purposes, why can't the url just naturally be shorter? | One reason is that long (and human readable) URL's are a part of search engine optimization (SEO), because URL's containing keywords from the content of the page tend to be ranked better than just random looking ones. Youtube is not a very good example for this though, because even the regular URL's are not human reada... | [
"There are several reasons to use URL shortening. Often regular unshortened links may be aesthetically unpleasing. Many web developers pass descriptive attributes in the URL to represent data hierarchies, command structures, transaction paths or session information. This can result in URLs that are hundreds of char... |
how come when having a sickness that requires medicine, i have to do it in a span of a week or a few days? | Accomodating the poor English, are you asking why you can't take the whole course of medication at once?
Let's use the antibiotic 'Gentamycin' for example. The drug is not easily filtered out by the kidneys, and an overdose would cause the kidneys to not work. That results in kidney failure and you'd potentially die.
... | [
"The current first-line treatment is fluconazole, 200 mg. on the first day, followed by daily dosing of 100 mg. for at least 21 days total. Treatment should continue for 14 days after relief of symptoms.\n",
"Treatment is typically with two doses of the medications mebendazole, pyrantel pamoate, or albendazole tw... |
Do we believe the figures for Ancient Battles? | This topic, depending on the battle, can be hotly debated among historians. Occasionally archeological evidence can shed light on the battles, but often historians must defer to the written record. That said, most historians won't take the figues exactly at face value. If the army in question is Egyptian, there may be ... | [
"There is a contrast between the mythical and historical events portrayed: depictions of Theseus' victory over the Amazonians and the Fall of Troy are juxtaposed sharply with the portrayal of the historic Battle of Oenoe (conjectured to have occurred in the pentecontaetia at Oenoe, Attica on the Thriasian Plain nea... |
relative to the size of time and space today, how big was the dot of condensed matter before the big bang. | First off, "before" the big bang is an absurd qualifier. Time, space and possibly causality too, originated at the big bang. Asking what happened "before" that is like asking what's north of the north pole - in other words, a statement so absurd that it's [not even wrong](_URL_0_).
But, to answer your question, curren... | [
"During the inflationary epoch about 10 of a second after the Big Bang, the universe suddenly expanded, and its volume increased by a factor of at least 10 (an expansion of distance by a factor of at least 10 in each of the three dimensions), equivalent to expanding an object 1 nanometer (10 m, about half the width... |
if our body focused on preventing telomere reduction, what changes might our bodies experience? | Cancer. Cells continuing to divide with no limit is called cancer.
If you mean instead "what would happen to us if our bodies focused on sustaining cells /efficiency as long as possible before natural cell death what would happen?" Is a much more interesting question. | [
"Telomere shortening in humans can induce replicative senescence, which blocks cell division. This mechanism appears to prevent genomic instability and development of cancer in human aged cells by limiting the number of cell divisions. However, shortened telomeres impair immune function that might also increase can... |
what is the difference in propaganda and fake news | Well, one thing to be cautious of, is that 'fake news' is thrown around with relative abandon today, even against news that is not, in fact, fake *or* propaganda, merely which contrasts against the viewer's given preference.
So in some ways, it is simply a slur against the reporting organization.
In cases where 'fa... | [
"Propaganda is information that is not objective and is used primarily to influence an audience and further an agenda, often by presenting facts selectively to encourage a particular synthesis or perception, or using loaded language to produce an emotional rather than a rational response to the information that is ... |
Did the Strategic Defense Initiative Real aka "Star Wars" really help Bankrupt the Soviet Union ? | No. This is a post-Cold War myth, written largely by people who would like to make SDI not appear to be the boondoggle it was, or to make it look like something that had a positive effect on diplomacy, rather than the more easily-documentable negative effect. Pavel Podvig has [written at length about this here](_URL_1_... | [
"The SDI program also held important budget implications. In May 1993 Aspin announced \"the end of the Star Wars era,\" explaining that the collapse of the Soviet Union had determined the fate of SDI. He renamed the Strategic Defense Initiative Organization as the Ballistic Missile Defense Organization (BMDO) and e... |
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