question stringlengths 3 301 | answer stringlengths 9 26.1k | context list |
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why are pumpkins carved for halloween? | In the rural areas where Halloween first became popular, people would carve out turnips or gourds and put candles in them as lanterns when they went from house to house pretending to be spirits of the dead. Carving faces in them made them creepier and more like a wandering spirit. Pumpkins eventually became popular because they grew like crazy, they became ripe in autumn, and they're MUCH easier to carve. | [
"Pumpkins are commonly carved into decorative lanterns called jack-o'-lanterns for the Halloween season in North America. Throughout Britain and Ireland, there is a long tradition of carving lanterns from vegetables, particularly the turnip, mangelwurzel, or swede. The practice of carving pumpkins for Halloween ori... |
why is conservatism/republicanism so intertwined with christianity in america? | _URL_0_
_URL_2_
_URL_1_
Basically christian denominations in the 1960's didn't like increasing secularism and the counter culture(hippies, liberalism, drugs). And while traditionally they shunned being involved in politics. They started to get involved starting in the early 1970's. And ever since, protestant christians are 70-85% of the republican base(numbering 60 million as of the past three elections) , while a third(20 million) being evangelicals. Making them a core component of the republican party.
| [
"The emergence of the \"Christian right\" as a political force and part of the conservative coalition dates from the 1970s. According to Cambridge University historian Andrew Preston, the emergence of \"conservative ecumenism.\" bringing together Catholics, Mormons, and conservative Protestants into the religious r... |
- how bets are placed during illegal fights like we see in the movies? | Someone at the event is a bookie. people yell out saying they want to put money on said action. The bookie can make odds and start taking bets, or choose not to take the action | [
"Bets were made back then as is still customary to this day. Bets were made on the results of the fight, on who'd draw the first blood, or on who would score the first knockdown. There were rules, but they were designed to accommodate gambling, the public, and those who organized the fight. The boxers themselves we... |
Is eating raw food at all healthier? | Depends on a couple of things: the food itself, the way it would have been prepared and what one means with healthy.
Raw egg for instance. Cooking has no negative influence on the quality or bioavailability of the protein - raw or boiled, all the same. However, raw eggs can contain bacteria in which case heating it up is the healthier option. The same applies to meat. However, watch out for polyaromatic hydrocarbons, especially when grilling the meat.
As for vegetables, some nutrients are more readily available when cooked, others are more prevalent when foods are eaten raw. Lycopene for instance, is more prevalent in cooked tomatoes than raw. On the other hand, vegetables can lose their water soluble vitamin during boiling due to them leaching. This is however much smaller problem if you for instance steam your veggies in the microwave, make soup out of them or bake them in the oven. | [
"One review stated that \"Many raw foods are toxic and only become safe after they have been cooked. Some raw foods contain substances that destroy vitamins, interfere with digestive enzymes or damage the walls of the intestine. Raw meat can be contaminated with bacteria which would be destroyed by cooking; raw fis... |
If a regime resembling Nazi Germany arose today, how would economic warfare change the conflict? | This roughly fits into the [no current events rule](_URL_0_) that we use since it's asking about something today. Perhaps reword the question in another way. | [
"During the Hitler era (1933–45), the economy developed a hothouse prosperity, supported with high government subsidies to those sectors that tended to give Germany military power and economic autarky, that is, economic independence from the global economy. During the war itself the German economy was sustained by ... |
Is the story about the Rothschilds gaining wealth through knowing Napoleon had lost true? | Short answer? Maybe. At the least, they were probably aware of the outcome of Waterloo quickly enough to make a profit from it. The Long Answer, though, is a little different. There's literally no way that he could have made a big enough profit on war bonds to account for the kind of stuff they claim - the market itself was nowhere near large enough. His business plan also relied on a long and protracted war, so, he probably *lost* money on it.
The reason it's all over the net is that, as you saw within this thread itself, the internet makes it *very* easy to spread misinformation - whether accidentally or intentionally. This has resulted in the modern conspiracy culture - where otherwise fairly-normal or educated people believe that the Jews - a faceless and all-powerful collective rather than a religion and ethnic group - run the world with the goal of destroying all that good God-Fearing Christians hold dear. | [
"Historian Niall Ferguson agrees that the Rothschilds' couriers did get to London first and alerted the family to Napoleon's defeat, but argues that since the family had been banking on a protracted military campaign, the losses arising from the disruption to their business more than offset any short-term gains in ... |
How did the modern German state of Saxony get its name? Wasn't Saxony originally near modern-day Denmark? How did a state in eastern Germany bordering the Czech Republic end up with the name Saxony? | In this answer I will look at the geographical movement of the political entity known as Saxony. The history of Saxony can be divided into 5 periods Old Saxony (also known as pre-ducal saxony), Duchy of Saxony, Electorate of Saxony, Kingdom of Saxony, and Free State of Saxony.
During the time of Old Saxony, unlike all other periods Saxony was not a political entity with clearly defined borders. Since at the beginning of the first millennium Saxons didn't have a written language all written sources about the origin of the Saxons are written by Romans. The first mention of Saxons in a primary source is Ptolemy writing about the Saxones tribe during the 2nd century. According to Ptolemy the Saxones lived near the northern parts of the river Elbe.
During the following centuries the Saxon tribes migrated slightly Westward until they inhabited the lands directly south of modern day Denmark. When the Saxons were conquered by Charlemagne near the end of the 8th century their lands are described as bordering the rivers of Ems, Eider and Elbe.
After their conquest by Charlemagne the Duchy of Saxony was created in 804 AD. The Duchy of Saxony was ruled by the Liudolfing, Billung, and Supplinburg dynasties from 804 to 1137. During this period the borders of Saxony didn't change all that much. In 1137 the Welf dynasty which also ruled over Bavaria(in south-eastern Germany) became the Dukes of Saxony. They ruled over Saxony until 1180. When emperor Frederick revoked Bavaria and Saxony from the Welfs. Frederick seperated the Archbishopric of Bremen and the Duchy of Brunswick-Lüneburg from Saxony, and gave the remainder of Saxony(the southern parts) to the House of Ascania.
In 1260 after the death of Albert I, his two sons(Albert II and John I) jointly ruled the duchy of Saxony. Eventually in 1296 the duchy was split between the two brothers with Albert II ruling over the Duchy of Saxe-Wittenberg, and the sons of John I ruling over the Duchy of Saxe-Lauenburg. Lauenburg was in the north of germany on the coast. Saxe-Lauenburg split up into even smaller duchies and then reunited, and eventually was annexed by Prussia.
Saxe-Wittenberg on the other hand was centred around the town of Wittenberg. Which was on the southern most parts of Saxon territory. Parts of this territory was ruled by the House of Ascania even before they became Dukes of Saxony. Which they used to rule over with their title as the Count of Anhalt.
Due to the Golden bull of 1356 the dukes of Saxe-Wittenberg became one of the 7 people with the authority to elect the Holy Roman Emperor, and Saxe-Wittenberg became known as the electorate of Saxony.
The borders of the Electorate of Saxony moved further south in 1423 when it merged with the Margravate of Meissen and Thuringia. When the Margrave of Meissen Frederick I became the Elector of Saxony after the death of the previous elector Albert III without any children.
The 1635 Peace of Prague gave Lusatia to Saxony moving the borders of Saxony eastwards.
The electorate of Saxony also broke up into various different territories, but eventually those territories united, but I won't elaborate on that here due to the fact that it's not too relevant to the movement of the borders of Saxony.
During the dissolution of the holy roman empire the electorate of Saxony became the Kingdom of Saxony in 1806. Due to Saxony supporting Napoleon during the war of the 6th coalition the congress of Vienna in 1815 gave the northwestern 40% of Saxony's territory to Prussia.
The remainder of the Kingdom of Saxony eventually became a part of the German Empire in 1871, eventually the German empire became the Weimar republic in 1918, and the Kingdom of Saxony became the free state of Saxony.
Sources:
Saxon Identities by Robert Flierman
Vienna 1814 by David King
Renaissance and Reformation by William Roscoe Estep | [
"The name of Saxony derives from that of the Germanic tribe of the Saxons. Before the late medieval period, there was a single Duchy of Saxony. The term \"Lower Saxony\" was used after the dissolution of the stem duchy in the late 13th century to disambiguate the parts of the former duchy ruled by the House of Welf... |
If you had unlimited time and resources, would it be possible to walk on the bottom of the marinas trench? | Short answer no. The physiology of a human will never be able to simply "acclimate" to the absolutely extreme pressures. [This blog post regarding travel to Challenger Deep](_URL_0_) from a marine biologist does an excellent job of 1) describing the immense pressure at those depths and 2) the array of physiological effects of such extreme pressures (besides the obvious being crushed one). | [
"Percolation trenches are often used to treat runoff from impervious surfaces, such as sidewalks and parking lots, on sites where there is limited space available for managing stormwater. They are effective at treating stormwater only if the soil has sufficient porosity. To function properly, a trench must be desig... |
why do whips make that big “wuh-psssh!” sound? | The tips of the whip actually break the speed of sound. The crack of the tip is making a sonic boom. | [
"There are two types of whips. The first has two planks of wood connected by a hinge, with a handle on each. The percussionist holds the instrument by the handles and hits the two pieces of wood together, creating a loud whip noise. The other type also has two planks of wood, one longer than the other, with one han... |
Learning about Physics from scratch? | 'Fundamentals of Physics' by Halliday, Resnick, and Walker is a great introductory text that covers most basic areas of physics. That would be my personal recommendation. | [
"The study and practice of physics is based on an intellectual ladder of discoveries and insights from ancient times to the present. Many mathematical and physical ideas used today found their earliest expression in ancient Greek culture, for example in the work of Euclid, Thales of Miletus, Archimedes and Aristarc... |
what do we reference a unit of measure to? how do we know an inch is an inch? | Right now, the meter is based on the speed of light in a vacuum, which is absolute and relatively easily reproducible.
"the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second." | [
"The inch (abbreviation: in or ″) is a unit of length in the (British) imperial and United States customary systems of measurement. It is equal to yard or of a foot. Derived from the Roman uncia (\"twelfth\"), the word \"inch\" is also sometimes used to translate similar units in other measurement systems, usually ... |
how do games make you smarter? | Usually RTS games make you think critically and use resources efficiently. MOBAs teach you to deal with assholes. | [
"Cognitive skills can be enhanced through repetition of puzzles, memory games, spatial abilities and attention control. Most video games present opportunities to use these skills with the ability to try multiple times even after failure. Many of these skills can be translated to reality and problem solving. This al... |
why do muslims believe it is empowering for women to cover their bodies? | I don't see how anyone can think it is empowering or not feel like an object when you literally have a sheet over you like some entrepreneur's big new invention. | [
"Al-Munajjid states that Muslim women are required to cover their entire body including the face (only showing eyes) and hands. This ruling is obligatory and does not vary depending where you are. Women are required to stay in their houses unless they are in the company of a mahram and are forbidden to drive cars a... |
What was a "Turk" to peoples of the 13th-16th centuries? | As an exonym, Early Modern Europeans often used the word "Turk" to describe any Levantine or Balkan Muslims, regardless of their looks or geographical origin. In the context of the time, it was more of a religious and political identity than an ethnic or linguistic identity that it is today. Essentially, "Turk" was a slang or shorthand for "Moslem from an Ottoman-controlled area". | [
"The first known mention of the term \"Turk\" (Old Turkic: 𐱅𐰇𐰼𐰰 \"Türük\" or 𐱅𐰇𐰼𐰰:𐰜𐰇𐰛 \"Kök Türük\" , Old Tibetan: duruggu/durgu (meaning \"origin\"), Pinyin: Tūjué, Middle Chinese (Guangyun): ) applied to a Turkic group was in reference to the Göktürks in the 6th century. A letter by Ishbara Qaghan to E... |
why is the average temperature of the earth still rising due to global warming even as holes in the antarctic ozone layer are healing? | These 2 things are unrelated. Global warming is mostly caused by an excess of greenhouse gasses. The holes in the ozone layer were caused by our use of CFCs which damage the ozone layer. Since CFCs were banned the ozone layer has been able to recover. | [
"BULLET::::- Chemistry-climate models predict that springtime Antarctic ozone levels will be increasing by 2010 because of projected decreases of halogens in the stratosphere. A return to pre-1980 total column ozone amounts in the Antarctic is expected by the middle of this century.\n",
"The 2010 report found, \"... |
why do websites such as pandora need to pay a licensing fee to play an artist's song, but websites like youtube don't have to? | Youtube is just hosting the videos. If an artist's "official" youtube channel posts a full song, the artist is already involved, and thus Youtube doesn't have to pay a fee. If the artist is not involved, they can send a claim to youtube, and youtube will take the song down - thereby not having to pay for use of the song.
Pandora, though, is attempting to directly profit off of the music - artists don't upload their own stuff to Pandora, Pandora itself collects the music and tries to bring it to users - therefore the artist only gets any sort of benefit (other than exposure, which not many of them need from Pandora) by charging a licensing fee. | [
"In 2014, Pandora signed an agreement with some music copyright owners for lower royalties in exchange for more frequent streaming of songs. Though not illegal, this practice raised comparisons to payola, which is illegal payment for airplay on terrestrial radio.\n",
"Some games which have used licensed music, su... |
where does the bank interest on a savings account actually come from? | When you deposit $1000 in a bank account earning 1%, they take most of that money and loan it out to someone else at, say, 3%. 1% goes to you, and 2% goes to the bank, to cover overhead, defaults, and to provide profit to the shareholders. | [
"A savings account is a deposit account held at a retail bank that pays interest but cannot be used directly as money in the narrow sense of a medium of exchange (for example, by writing a cheque). These accounts let customers set aside a portion of their liquid assets while earning a monetary return. \n",
"A sav... |
what is the "hierarchy" and difference between the different kinds of courts i hear about? | Assuming you are talking about the United States, there are two types of courts - Federal and State.
Courts, broadly, are either courts of first instance (the first court that you file a lawsuit or start a trial in,) or appellate courts (courts that hear appeals from lower courts.) Some courts are courts of first instance for certain matters and appellate courts for other matters.
State courts vary from state to state. Taking California as an example, they have the Superior Courts of California (one for each county) which are the courts of first instance. Decisions from the Superior Courts are appealed to the California Courts of Appeal, of which there are 6. The court of last resort is the California Supreme Court, and decisions from that court can be appealed to the Supreme Court of the United States.
Federal courts start out with the District Courts, which are courts of first instance for Federal matters. Each state has between 1 and 4 District Courts. Appeals from the District Courts are heard by the United States Court of Appeals, of which there are 12 different Circuits responsible for various District Courts. Appeals from the US Court of Appeals are heard by the Supreme Court of the United States.
Some states have separate Criminal and Family courts, which are courts of first instance for Criminal and Family matters respectively. | [
"The hierarchy consists of a variety of courts and tribunals at both the federal and state and territory levels, with the High Court being the highest court in the Australian judicial system. A single body of Australian common law is applied in the various Australian courts, and ultimately determined by the High Co... |
how is the futures trading market different from gambling or betting? | Gambling is totally random based on odds of things happening. Futures are still based on the same fundamentals that stock purchases are made. There is some additional risk because you are adding a time component, but you are still using the available information about the underlying asset and economy as a whole in order to trade. You can research and determine whether the economy will slow down or speed up. You can research how demand is shifting. You can research weather patterns.
Let's say you're trading wheat futures... you can see how the economy affects demand -- do people eat less wheat when they cut back, or do they shift to wheat-based products (pasta, for example) as a cheaper alternative to meat-based meals? Has China or India suddenly discovered the wonders of fresh bread? Or has the U.S. and Europe jumped on the low carb craze? Have drought conditions impacted the wheat crop in the Midwest? Or was there a bumper crop this year? All these are things that can be researched and used to determine which way futures will move and trade accordingly.
Additionally, the fundamental purpose of futures is to mitigate risk, for those creating the good (oil company, farmer, mining company) and those consuming it (oil refineries, food producers, steel makers) because the seller and buyer can both lock in a price for the resource. | [
"Betting exchanges compete with the traditional bookmaker. They are generally able to offer punters better odds because of their much lower overheads but also give opportunities for arbitrage, the practice of taking advantage of a price differential between two or more markets. However, traditionally, arbitrage has... |
If a moderately well-off citizen of ancient Rome wanted to take his family on a vacation, what sort of options would be open to him? | not discouraging anyonen with specific information about vacation options in ancient Rome, but FYI there have been several questions about vacations in ye olde days. I've taken this opportunity to do a general roundup (with an eye to adding them to the "popular questions" wiki); I've indicated which ones include responses mentioning Rome, so you'll find lots of ideas here:
**Vacations in general**
[When did traveling for pleasure become popular?](_URL_2_) Rome
[At what point in time did traveling for leisure become normal?](_URL_4_) Rome
[When were vacations (as we know them) "invented"?](_URL_5_) no
[When and where did tourism start?](_URL_8_) Rome
[When and why did people start leaving home for short vacations?](_URL_0_) Rome
[When did tourism become a large part of countries incomes?](_URL_9_) no
[Did people use boats and ships as pleasure craft before modern times?](_URL_10_) Rome
**Going to the beach**
[Did ancient peoples "go to the beach" as we do today?](_URL_6_) Rome
[When did we start going to the beach?](_URL_11_) Rome
[When did "going to the beach" become a popular, recreational activity?](_URL_1_) no
[Question about beach culture in England.](_URL_7_) no
[When did "going to the beach" become a popular way to spend time?](_URL_3_) no
| [
"It appears to have early become a favorite resort with the wealthy Romans as a place of retirement and pleasure; thus we find that Pompey the Great had a villa there, and Julius Caesar also, where he landed on his return from Africa, and at which all the nobles of Rome hastened to greet him. Another is mentioned a... |
To what extent were African Americans involved in Marxism and what were Soviet opinions of African Americans? | Whilst this is only an incomplete answer, the career of the Trinidadian journalist [George Padmore] (_URL_2_) might be of interest. He became a communist whilst studying medicine in the USA, and his eloquence and intelligence gave him the opportunity to visit Moscow for the 1929 Communist International. After the conference, he decided to stay in Moscow and was elected onto the Moscow City Soviet (essentially the city council). He also served as one of the very few black members of the Communist international, employed to help establish communist movements in Africa.
By 1933, however, Padmore had grown disillusioned with what he perceived to be a lack of anti-colonial activity on behalf of the Communist International. He rebelled against this, and was expelled from the Party in 1934. Following this, he became a dedicated pan-Africanist, particularly notable for his close advisory friendship with Kwame Nkrumah, the first leader of independent Ghana.
Whilst not African-American, he does indicate that whilst the Soviet Union was not averse to blacks in leading positions, they nonetheless did not direct much attention to the liberation of colonised nations, nor were there significant numbers of black Communists in Russia in the pre-war period.
A few African-American figures who might be of interest, however, include:
[Bayard Rustin] (_URL_4_) - close advisor to MLK and the SCLC during the 1950s and 1960s, who was affiliated with the Communist party before 1941
[Angela Davis] (_URL_3_) - former leader of the Communist Party USA, Black Panther, renowned African-American activist and scholar
[Robert Williams] (_URL_0_) - Black nationalist and early proponent of armed self-defence who fled the USA to exile in Cuba and communist China. Whilst not (as far as I am aware) ever a Communist in the truest sense of the word, he worked on Radio Free Dixie during his time in Cuba and endorsed North Vietnam during the Second Indochina War.
[Paul Robeson] (_URL_1_) - activist, singer, actor and author. He was strongly affiliated with anti-colonial and Communist groups, and his career was callously destroyed by McCarthyism. He sent at least one of his children to be educated in Russia to escape the racism of the USA.
These are just a few characters off the top of my head. There's certainly no suggestion that they worked for the Communist party as sources, at least in what I have read on them. They weren't necessarily allied with the Soviet brand of Communism - indeed, more often than not they were opposed to it.
Outside of the USA, and especially in Africa, Communism was also prevalent (oddly, it was almost invisible in the Anglophone Caribbean). Communist governments and communist parties assisted a number of anti-colonial movements including the ANC, ZANU-PF, FRELIMO, and the MPLA in the struggle against imperialism. Indeed, Zimbabwe remains one of the few centrally-planned Marxist economies in existence. | [
"The Communist Party USA, ideologically committed to foster a socialist revolution in the United States, played a significant role in defending the civil rights of African Americans during its most influential years of the 1930s and 1940s. In that period, the African-American population was still concentrated in th... |
Is the Human Brain Turing Complete? | Your question as I read it is different from your description. Turning complete basically means you can calculate what a Turing machine can calculate, which your brain can do.
In your description you ask if the brain could compute in the same way as a computer. Yes and know, you can calculate the same thing, but not in the same way. In fact the big push over the last decade or so is in the field of machine learning and neural networks, which attempts to get computers to think like people do.
The difference is decisions, computers with standard programming cannot "decide" to do something, it executes its program. With neural networks machines can learn and change the rules, or even its own programming and "decide" to do something different.
This link is a bit old but still pretty awesome, a computer that taught itself and discovered some of the laws of physics on its own. Some have made independent discoveries than mankind had not.
_URL_0_ | [
"Turing did not claim that the human mind really is a digital computer. More modestly, he proposed that digital computers might one day qualify in human eyes as machines endowed with \"mind\". However, it was not long before philosophers (most notably Hilary Putnam) took what seemed to be the next logical step—argu... |
why do so many different species (whales, humans, pigeons) have such similar bodily structures (2 eyes, 2 ears, digestive tract)? | In most cases, common descent - we all share an ancestor that, however long ago, had two light-sensing organs or a digestive system or whatnot.
In quite a few cases, convergent evolution - two different species develop a trait independently from one another due to similar selection pressure or to "solve" a similar problem - such as wings in insects, birds and mammals. | [
"There may be differences in pupil shape even between closely related animals. In felids, there are differences between small- and large eyed species. The domestic cat \"(Felis sylvestris domesticus)\" has vertical slit pupils, its large relative the Siberian tiger \"(Panthera tigris altaica)\" has circular pupils ... |
Why does carbon monoxide bond so strongly to iron in hemoglobin? | Oh I'm very happy to answer this question. So this question delves into organometallic chemistry. If you look at the structure of CO, there's a triple bond between carbon and oxygen, and surprisingly the carbon has a lone pair and is the anionic end while the oxygen has only a single lone pair and is the cationic end. This is fairly unstable as the oxygen's electronegative trait wants to be more electron rich, and the molecule as a whole wants another pair of electrons to interact with the carbon so the oxygen can get dominance over its electrons again. The iron in a heme center is a perfect candidate for this, and another factor comes into play here. The anionic carbon acts as a good nucleophilic sigma bond donator, but it also has a characteristic of what's called a pi-bond acceptor, as the carbon has a empty anti-pi orbital to form a reinforcing bond with the electrons from iron. Once this interaction has formed, it's highly unfavorable for it to be released as this means the oxygen would have to re-donate one of its lone pairs to make a triple bond with the carbon to reform CO. | [
"The binding of oxygen is affected by molecules such as carbon monoxide (for example, from tobacco smoking, exhaust gas, and incomplete combustion in furnaces). CO competes with oxygen at the heme binding site. Hemoglobin's binding affinity for CO is 250 times greater than its affinity for oxygen, meaning that smal... |
why is bob my uncle? | “Bob's your uncle” is a way of saying "you're all set" or "you've got it made." It's a catch phrase dating back to 1887, when British Prime Minister Robert Cecil (a.k.a. Lord Salisbury) decided to appoint a certain Arthur Balfour to the prestigious and sensitive post of Chief Secretary for Ireland. Not lost on the British public was the fact that Lord Salisbury just happened to be better known to Arthur Balfour as "Uncle Bob." In the resulting furor over what was seen as an act of blatant nepotism, "Bob's your uncle" became a popular sarcastic comment applied to any situation where the outcome was preordained by favoritism. As the scandal faded in public memory, the phrase lost its edge and became just a synonym for "no problem”.
(Copy and paste from the first google result) | [
"Uncle (1964) is a children's novel written by J. P. Martin, the first book of six forming the \"Uncle\" series. It is named after the main character, a rich philanthropic elephant who lives in a huge fantastical castle populated by many other eccentric animals and people. It was illustrated, like the others in the... |
why are the violent drug cartels not considered terrorist groups? | A "terrorist" is a person who is trying to use terror (fear) to influence politics.
The drug cartels aren't in it for the politics. They're in it for the money. So that makes them not terrorists, just regular criminals.
| [
"The drug cartels have fought back violently against the military and have used violence to strke fear on the civilian population. In addition, journalists have also been targets of the drug gangs when they have reported on their criminal activities.\n",
"In a CBS news article, the Chief of Operations for the US ... |
Assuming this is not staged somehow, can someone explain the physics of how this is possible | It's not staged.
The key factor is that the table sways somewhat from each metronome. This swaying allows each metronome to interact and interfere with the others and this tends to push them into synch.
It takes some pretty complex differential equations to prove this, but when you work it out, the result is that the interactions force the metronomes into synchronicity. | [
"BULLET::::- Forum Theatre - The actors either create a planned improvisation or create a piece spontaneously, as it is performed the audience can either stop the action to suggest changes or take over from the actors on stage to change the direction of the performance. Quite often this is used as an exploration to... |
how do competitive eaters fit all the food they eat in their stomach? | You eat massive amounts in training and it stretches out your stomach. The stomachs of competitive eaters are much more elastic than normal people. | [
"The Great American Eat Off - a show that pits two average eaters against each other to see who can eat the fastest, while raising awareness for charity and then brings in a professional competitive eater to beat the winning time, raises the stakes for competitive eaters by incorporating various challenges and obst... |
can the president be arrested? | Probably not. It's not settle law because normally the President isn't a criminal.
_URL_0_
President Grant was once given a speeding ticket though. | [
"General Order № 2 – The President directed the Minister of National Defense to arrest or cause the arrest and take into his custody the individuals named in the attached list and to hold them until otherwise so ordered by the President or by his duly designated representative, as well as to arrest or cause the arr... |
Why did so many bombs not explode when they were dropped on Vietnam/Laos? | There is always a base failure rate with any technology. Bombs are no different in this respect (and many of them are more complicated than you might realize, and complication often adds new failure modes). So let's imagine you have a bomb that works 99.9% of the time — that is way higher than the success rate of many bombs (some modern bombs apparently have failure rates at least as high as 7% — I've no idea how high it goes today, or what it was back then) but it illustrates our purpose. How many bombs are we talking about? There was apparently around 7 million tons of bombs dropped on Vietnam by the US during the war. So if .1% of those failed, then we're talking about 70,000 tons of unexploded munitions randomly dispersed around the country. If we use more realistic failure rates, we might come up with several orders of magnitude more (with 7%, we have ~500,000 tons — note that the individual bombs usually weighed well under a ton, and with cluster munitions, you can have individual bombs that weigh practically nothing, so that weight would mean a _lot_ of unexploded ordnance).
So the real issue is not how difficult it is to make a bomb explode — maybe you can do that really, really well. The question is, what's your total sample size? And in the case of Vietnam, it is HUGE — we dropped way more tonnage on Vietnam than was expended by all sides during World War II (which was about ~2 million tons of TNT equivalent, _including_ the two atomic bombs). So even a very small failure rate would have left a lot of unexploded ordinance, and under jungle conditions the failure rate was probably relatively high anyway.
TLDR;: The issue is not how faulty the bombs were so much as it is how many bombs were dropped. | [
"During the Vietnam War, Laos was the target of the heaviest US bombing campaign, making Laos the most bombed country in history: from 1964 until 1973 more than two million tonnes of bombs were dropped, including 260 million cluster munitions. An estimated 30% of the bombs dropped failed to detonate as intended. Un... |
how come the percentage of left handed people is so much higher in the mlb than in real life? | Left-handed hitters are a couple of steps closer to first base.
Left-handed first-basemen have their glove hand in a better position to catch pickoff throws.
Left-handed pitchers have a better view of the runner on first. | [
"For reasons that continue to spur debate, it is historically the case that most right-handed pitchers succeed at higher rates against right-handed hitters than against left-handers, and that most left-handed pitchers succeed at higher rates against left-handed hitters than right-handers.\n",
"BULLET::::- In base... |
When does one use Hilbert Space instead of Euclidean Space? | > * A Hilbert Space has infinite dimensions
> * An Euclidean Space has finite dimensions
This is incorrect. A Hilbert Space is any vector space that 1.) Has an Inner Product and 2.) Is "complete", which means limits work nicely. In particular, the vector space R^(n) with the standard dot product is a finite dimensional Hilbert Space. A Euclidean Space is not a vector space, but is an [Affine Space](_URL_1_). An Affine Space is, essentially, a set of points that can be moved around by vectors from some vector space. If we take R^(n) and forget everything about vector addition and the origin, then we'll have Euclidean n-space. Affine spaces are homogeneous, no point is special or central, and we can't add points together, whereas in a vector space 0 is always a special point and we can combine two through addition to get a new vector. However, if P is a point in Euclidean n-space and v is a vector in the vector space R^(n), then we can push P along v to get v+P, which is (essentially) where the vector v would be if we put the origin of R^(n) on P. Distinguishing Affine Spaces and Vector Spaces may not seem important, but it is.
But your question, fundamentally, is not about Affine Spaces vs Vector Spaces. It's more infinite dimensions vs finite dimensions. But there are *tons* of infinite dimensional spaces used everyday. Of particular importance are [L*_p_*-Spaces](_URL_2_). The vectors in an L*_p_*-Space are functions f(x) from some set X into the real or complex numbers so that the integral of |f(x)|^(p) over the whole space is finite. If X is infinite, then so is the dimension of the corresponding L*_p_*-space. These spaces have use in everything from the most abstract math to the most practical engineering. In particular, if you want to study the solutions to partial differential equations, then you'll need to work in spaces like these (possibly even larger spaces).
However, not all L*_p_*-spaces are Hilbert Spaces. For example, the set of sequences a*_1_*,a*_2_*,... so that the sum of |a*_i_*|^(p) is finite is an L*_p_*-space, but it is not complete. Moreover, if p is not equal to 2, then the L*_p_*-space is not an Inner Product space, so it is not a Hilbert Space (though it can be a [Banach Space](_URL_0_) if it is complete).
Infinite dimensional Hilbert Spaces are probably some of the most important things in math. In particular, the L*_2_*-space is incredibly powerful and practical. Since it's elements are function, we do not need to write them in terms of their infinite base, we just need to be able to write down and evaluate the function. Since it is a Hilbert Space, limits work really well, amd we can generally approximate all of these functions using really simple functions, like polynomials. So there is really no issue that is infinite dimensional. L*_2_*-spaces are also the fundamental framework for Fourier Transforms, and you can't get more practical than that!
A lot of the stuff that is familiar in finite dimensional spaces does not work in infinite dimensional spaces, so it is critical to study them on their own. The study of these spaces, and function spaces in particular, is [Functional Analysis](_URL_3_). | [
"The mathematical concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra and calculus from the two-dimensional Euclidean plane and three-dimensional space to spaces with any finite or infinite number of dimensions. A Hilbert space i... |
how do computers recognize different styles of code? | They don't.
Computer actually have only one style of native code. everything else needs to be translated into that.
Usually this is done with a compiler a program that turns human readable code into machine code.
Sometimes for code in programming languages that are used for scripting, instead of compiling the code once and running the resulting binary executable again and again the code gets translated "on the fly" every time it is run by an interpreter program.
The computer "knows" which interpreter or compiler to use for which sort of code the same way that it knows to use for example Word to open a word-file or paint to open an image file. Mostly a combination of the extension (and sometimes the mime format) of the source file and the user manually selecting the file from the right program. | [
"Software classification is the process of identifying similarities between different software binaries (for example, two different versions of the same binary) used to detect code relations between software samples. This task was traditionally done manually for several reasons (such as patch analysis for vulnerabi... |
why do different engines need different fuels? what is the difference between these fuels? | So, you put fuel into an engine and the engine then also takes in air, and then either the spark plug sparks it, causing the fuel to combust OR with diesel fuel, compressing the fuel causes it to ignite on its own. The difference in octane rating (89, 91, 93 etc) is that the higher the rating, the less it "knocks," or, basically combusts too soon while it's being compressed inside the piston. In higher performance vehicles, the higher octane fuel is needed for "timing" - the turning of the crankshaft in time to the combustion of the pistons as the system turns around. Basically, octane ratings relate to how soon the fuel combusts inside the piston. In real time, we're talking about milliseconds difference, but this timing makes a HUGE difference over the life of the engine. If you ran 89 octane in a vehicle that needed premium, you probably wouldn't see a huge difference immediately, but over time the valves, cams, pistons - everything associated with combustion and timing - would be thrown off and would wear funny. Not only that, but you would start to get that characteristic pinging or knocking sound that comes from premature firing. | [
"Fuel variety plays a significant role in the dynamics and characteristics of engine performance, the operating cost of an aircraft and ultimately the safety and reliability of an engine. Conventional fuels consist of jet fuel and AVGAS (aviation gasoline), which differ from automotive engine fuels. These are fuels... |
why do we go from 11am to 12pm then 1pm and 11pm to 12am then 1am. shouldn't it be 11pm, 12pm, 1am? | AM stands for ante-meridian. PM stands for post-meridian. Meridian in both these contexts talking about noon | [
"Noon (also midday or noon time) is 12 o'clock in the daytime, as opposed to midnight. The term 12 p.m. (for post meridiem, and also written as 12 pm or similar variations thereof) is sometimes used for noon.\n",
"In the United States and Canada, digital clocks and computers commonly display 12 a.m at midnight. T... |
How fast is our galaxy traveling through the universe? | > [Speed relative to CMB rest frame: 552 km/s.](_URL_0_)
Just a note, there is no center of the Universe. Our speed relative to the [cosmic microwave background radiation](_URL_1_) is the closest we have to the idea of our "speed through the Universe." The rest frame of the CMB is the frame of motion in which the [red shift](_URL_2_) of the CMB is uniform in all directions. | [
"The Andromeda Galaxy is approaching the Milky Way at about as indicated by blueshift. However, the lateral speed (measured as proper motion) is very difficult to measure with a precision to draw reasonable conclusions: a lateral speed of only 7.7 km/s would mean that the Andromeda Galaxy is moving toward a point 1... |
amiibos | They sell out so fast mostly because they are highly collectible (like limited edition action figures and other related toys). There are people who like to collect large numbers of them even though they don't actually use most of them for their intended purpose.
Amiibos are basically figurines of Nintendo video game characters. They have a special RFID type chip built-into them which lets you gain access to bonus video game content and/or save game states by holding the Amiibo characters against a wireless transceiver built-into a Wii-U or 3DS XL. | [
"Amikumu ( ; ) is a cross-platform app for smartphones (Android and iOS) which can be used to find people nearby who speak or learn the same languages as the user. The app was launched for Esperanto speakers on 22 April 2017 and for speakers of all languages during LangFest in Montreal on 25 August 2017. On 9 Augus... |
how do electric vehicles cut down on carbon emissions? i know they don't use gas but don't we still have to burn coal etc to power them up? | Power from power plants is often times much more efficient. It’s like how BNSF advertised that, by scale, a train gets roughly 340mpg compared to other shipping methods like trucks.
Also, power comes from multiple sources including clean sources like hydro, wind, solar, nuclear, etc. Tesla’s Gigafactory is also powered by renewables.
The idea is that overtime, as renewables take over, the carbon footprint of electric cars will fall even further. | [
"By converting the lost heat into electricity, ATEGs decrease fuel consumption by reducing the electric generator load on the engine. ATEGs allow the automobile to generate electricity from the engine's thermal energy rather than using mechanical energy to power an electric generator. Since the electricity is gener... |
Aliens through history | It's modern. Before aliens there were demons, witches and so on. Although not a historical work, Carl Sagans *Demon haunted world* deals very much with alien abductions, how they came about and what was in their place before anyone thought about aliens. | [
"BULLET::::- Enigma (1986, ) : Set 150 years after the events of the first book, the 'aliens' turned out to be human and considered themselves to have been colonized from Earth in the distant past. The Unified Space Survey has been established to make contact with other remnants of the first colonization and to det... |
deficit goes down but debt ceiling goes up. why? | If you spend $1000 in a year, and you earn $500 in that same year, your deficit is $1000 - $500 = $500. You have to borrow $500 to make it up.
Now imagine next year you spend $900 and make $600. Your deficit is $300, which is lower than the previous years'. But you still have to borrow $300 which, when added to the existing debt from the previous year, gives you $800 of debt. Your deficit has gone down but your debt has gone up.
Debt goes down when the deficit is *gone*. | [
"In a press conference held on January 14, 2013, President Obama stated that not raising the debt ceiling would cause delays in payments including benefits and government employees' salaries and lead to default on government debt. President Obama urged Congress to raise the debt ceiling without conditions to avoid ... |
when you shake a bowl of nuts, why do the larger ones come to the top? | Because the gaps between items are small and the small items find it easier to fall through those small holes. | [
"BULLET::::- When a container of mixed nuts is opened after it has been shaken, the larger nuts tend to be on top. This phenomenon is known as the \"Brazil nut effect\" in the study of granular materials.\n",
"BULLET::::- The center of mass of the whole system (containing the mixed nuts) in an arbitrary state is ... |
Is there a theoretical limit to how many immunities you can acquire? Does acquiring new immunities reduce the immune response of previously acquired immunities? | No, there is no theoretical limit, however not all immunity is lifelong and immunity will fade if you are not re-exposed to the pathogen.
When you become immune to a pathogen, a really complex process is taking place involving pre-existing immune cells, genetic recombination, innate responses, and a host of other things. You naturally have white blood cells conferring immunity to millions of things you have never been exposed to, just by random antibody production. When you are exposed to a pathogen, an immune cell (or, more often, several cells) recognize that as the pathogen they will respond to, and they replicate, make more antibodies, recombine to be more efficient, and produce the ability to mount an "anamnestic response", or immunity. | [
"Adoptive immunotherapy seeks to expand a population of the body's T-cells that will recognize a specific tumor antigen. T-cells can be harvested and then expanded and genetically manipulated to recognize certain tumor markers. In one case, a patient with advanced epithelioid sarcoma who had failed multiple therapi... |
why can dvd movies only so videos at a low resolution but games on a dvd can hold hd textures? | A movie needs to store every frame, while a game actually generates new frames as you play it. The only things that need to be on the disk are the raw resources from which the frames are generated, and those can be heavily re-used. If a texture is used in ten hours of gameplay, it's still the same single texture that only takes up so much space on the disk, while if you had ten hours of video footage of the same object, the video file would still need to store ten hours' worth of frames.
Also, a DVD can actually store quite a lot of data. DVD movies look bad because they use an old, primitive video encoding method that is very inefficient. You can easily store two or three full-length high-quality 1080p movies on a single DVD if you use a modern codec like H.265, which is much better at packing videos into small files while preserving quality. | [
"DVD-10 discs fell out of favor because, unlike dual-layer discs, they require users to manually flip them to access the complete content (a relatively egregious scenario for DVD movies) while offering only a negligible benefit in capacity. Additionally, without a non-data side, they proved harder to handle and sto... |
Did the Nazis ever specifically aim to bomb British landmarks? Or vice versa? | The [Hermannsdenkmal](_URL_0_) (in memory of Arminius' victory at the Teutoburg Forest) was riddled with [bullet holes](_URL_1_) (click on the picture to enlarge) by passing Allied planes. I suspect that was more a case of "celebratory gunfire" than the result of any planning though.
The letter quoted on this page mentions that the statue was "bombed but not hit", but the writer did not witness the attack ot it's aftermath himself, so a dose of salt is warranted. | [
"Public opinion in Britain throughout the 1930s was frightened by the prospect of German terror bombing of British cities, as they had started to do in the First World War. The media emphasized the dangers, and the general consensus was that defense was impossible and, as Prime Minister Stanley Baldwin had said in ... |
why are we not in full control of our brains although we are the host? | Imagine if you could alter how the engine in your car performs at any moment. Chances are, you'd tweak settings that might ruin the engine permanently. Same thing with your operating system -- there are settings you can't change (or have very restricted access to) because messing around with those settings can cause a lot of damage.
Your brain is largely the same way. If you could consciously change how your body behaves, you'd have a very high likelihood of hurting yourself. In addition, if the processes in your body were controllable, you'd have to *always* be monitoring them, which would consume a lot of your time. By having them automatic and "in the background," you can focus on more important things, like staying alive.
And "important" brings up another point: there's no real benefit to having these things consciously controllable vs having them be automatic.
So in the end, there's no real reason to have conscious control over the things that are automatic. | [
"For example, philosopher Daniel Dennett has proposed that humans are genetically predisposed to have a theory of mind because there has been evolutionary selection for the human ability to adopt the intentional stance. The \"intentional stance\" is a useful behavioral strategy by which humans assume that others ha... |
what is the deal with equifax breach to a non-american | Equifax is a credit reporting agency, meaning that they track the financial activity of Americans and provide information on their credit worthiness to banks and other institutions. If you want a loan, open a credit card, even get a new job in some cases, they will pull a report of your credit from one of the three credit reporting agencies.
This means they have an enormous amount of deeply sensitive information on Americans. Your name, all your past addresses, social security numbers, what outstanding loans you have and more. The fear is that with the information leaked, identity thieves will have all the information necessary to impersonate you and take out credit fraudulently without anyone knowing. If they get the information from Equifax and the bank calls Equifax to verify your identity, they'd never know the difference.
What makes this worse is that this didn't just happen, in fact it happened months ago. On top of that, executives at Equifax made a number of sales of the company's stock in the time between when the breach happened and when it was reported, raising concerns that they knew and sought to cash out before the value fell. | [
"In September 2017, Equifax announced a cyber-security breach, which it claims to have occurred between mid-May and July 2017, where cybercriminals accessed approximately 145.5 million U.S. Equifax consumers' personal data, including their full names, Social Security numbers, birth dates, addresses, and driver lice... |
why can i get my right leg almost over my head while my left leg i can barely get within a foot of it? | The simple answer is just that your right hip joint is more flexible than your left. Could be a combination of hyper-mobility (increased range of motion) in your right joint and/or ankylosis (decreased range of motion) in your left joint. Being more flexible in one joint but not the opposite it pretty common actually. | [
"When the pelvis descends on the unsupported side, the lower limb becomes, in effect, too long and does not clear the ground when the foot is brought forward in the swing phase of walking. To compensate, the individual leans away from the unsupported side, raising the pelvis to allow adequate room for the foot to c... |
Is there a universal coordinate system for .. the universe? | There is no special frame of reference. There is a distinction between inertial and non-inertial frames. | [
"In astronomy, a celestial coordinate system (or celestial reference system) is a system for specifying positions of celestial objects: satellites, planets, stars, galaxies, and so on. Coordinate systems can specify an object's position in three-dimensional space or plot merely its direction on a celestial sphere, ... |
if a gallon of gasoline weighs only 6 lbs, how does it produce 20 lbs of co2? | The gasoline supplies only the carbon (C), the oxygen (O2) comes from the atmosphere. Carbon weighs 12 grams per mole, oxygen weighs 16 grams per mole, so for every kilogram of carbon you need 2.67 kilograms of oxygen. The carbon content of gasoline depends on which molecules are in it; if we assume pure octane (C8H18), then 6 pounds of gasoline contains 5 pounds of carbon, ~~which should produce 13 pounds of CO2~~ which requires 13 pounds of oxygen and produces 18 pounds of CO2 (also, the 1 pound of hydrogen will, after combustion, produce H2O (water) which should weigh 8.5 pounds, if I've done the math correctly).
Edit: math correction. Full points to /u/tyr02 for finding the mistake. | [
"In 1994, the US National Institute of Standards and Technology (NIST) defined \"gasoline gallon equivalent (GGE) means 5.660 pounds of natural gas.\" Compressed natural gas (CNG), for example, is a gas rather than a liquid. It can be measured by its volume in standard cubic feet (ft³) (volume at atmospheric condit... |
Is a drug-resistant TB epidemic possible? | [Searched](_URL_7_)
Relevant [discussion](_URL_3_)
Original question by [TubeZ](_URL_4_)
> With recent articles about Totally drug-resistant TB, is there reason to be concerned about it?
Relevant comment courtesy [Teedy](_URL_0_)
> TB spreads as airborne spore, and has well and truly been very nearly eradicated for most intents and purposes in first world nations.
> It is highly virulent, but can lie latent for years, and a healthy immune system is typically capable of fighting it off.
> TDR does also not mean it's completely not susceptible to antibiotics, just that it is resistant this means higher doses and expanded drug regimes.
> It's a concern, any resistant organism is, but as we're finding with other bacterium a lot of time they lose their immunity to older drugs over time, and so cycling of antibiotics is very helpful, there are also a lot of new antibiotics being used, and as far as I recall reading, TDR-TB was treated
> Isoniazid/Rifampin is common practice for TB, after that things like levofloxacin and some polypeptides are used, after that we use rifabutin and possibly even linezolid.
> The reason's it's prevalent in third world nations in such great quantity comes from many things they are lacking, first, knowledge and proper sanitation are still huge problems in these nationes. TB is very hardy environmentally, but other diseases that make you more susceptible to im are hugely prevalent in these parts of the world as well. There's no education about finishing drug treatment regimes either, and TB has an especially long one, 6 months is a typical minimum. Thirdly, the 2nd and 3rd line drugs are prohibitively expensive for these nations.
Relevant [follow-up](_URL_5_) courtesy [pancititito](_URL_2_)
> To answer your question in short, yes this is real, but no, we (the general public) shouldn't be afraid, unless you are in direct contact with these individuals, and especially not if you are in a country with a very low incidence of TB, such as the United States. Still, resistance is and has been increasing in Mycobacterium tuberculosis (Mtb), so this is a real concern among those that are working towards eradicating it on a global scale.
> To put things in perspective, about 2 billion people world wide are infected with Mycobacterium tuberculosis. Of these 2 billion only 5-10% will ever get sick, even if they are not treated. This often occurs when an individual becomes immunocompromised. This could be in HIV-positive individuals or in those being treated with immunosupressants (you may recall hearing commercials recommending being tested for TB before taking rheumatoid arthritis drugs, this is why). Still as so many people are infected, there are about 8 million new cases of TB and ~2 million deaths a year (the WHO just released a report saying that this number is finally starting to decline after being on the rise since the 80s).
> Despite these high numbers of infection world wide, countries like the United States still have a very low rate of tuberculosis. In my state for example, there are only about 70 cases a year out of about 6 million people, usually in high risk environments or among immigrant populations. While the use of antibiotics helped to reduce the numbers and keep them low in the US, clearly this wouldn't help if we were combating a total drug resistant strain. From what I understand through discussion with heads of my state's health department, though, is that all of the drug resistant strains of Mtb found here are found within a specific immigrant population, suggesting that if a total drug resistant strain was introduced through immigration, it may not spread quickly through the general population.
> As already mentioned, there is a vaccine for Mtb, a live attenuated Bacille Calmette-Guérin (BCG) strain of Mycobacterium bovis (part of the Mtb complex this species very similar to Mtb and also causes TB in humans as well as cows and other animals like badgers and wild boars). This however does not bring a lot of comfort when considering a large scale drug resistant outbreak as studies have shown a range of efficacy from 0-80% among adults. Additionally, among immunocompromised individuals, BCG can cause infection and even death ([source](_URL_1_)). Because of this TB vaccination is still an active field of research. BCG does have a proven effect against disseminated TB in children however, and this is largely why it is still in use in countries with a high prevelence of TB.
> I don't have a lot of time now so I've left out some sources, but will come back and add in more details and sources here or in response any questions I get. I should also say that while I work with Mtb, it is not on an epidemiological level, so any epidemiologists should feel free to chime in if I've made any mistaken assumptions. Here is some more information from the [World Health Organization](_URL_6_). | [
"Primary resistance occurs when a person becomes infected with a resistant strain of TB. A person with fully susceptible MTB may develop secondary (acquired) resistance during therapy because of inadequate treatment, not taking the prescribed regimen appropriately (lack of compliance), or using low-quality medicati... |
How is it possible that negative heat capacities exist, and what do they mean physically? | That sounds like a mistake or typo in your book. NIST, the main organization that keeps track of reference data values, [shows Pyrite](_URL_1_) as having a positive heat capacity for all reasonable temperatures.
[Negative Temperature](_URL_0_) does exist, but it's mostly a weird quirk of our mathematical description of temperature applied to some VERY niche situations, and is almost certainly not what your homework is referring to. | [
"Most physical systems exhibit a positive heat capacity. However, even though it can seem paradoxical at first, there are some systems for which the heat capacity is \"negative\". These are inhomogeneous systems that do not meet the strict definition of thermodynamic equilibrium. They include gravitating objects su... |
is a sneezes volume/style hereditary, learned behavior, some other influences or are there no influences whatsoever? | Style is definitely learned. We attache some syllables to the act of sneezing that vary by geographic location.
_URL_0_ | [
"There is much debate about the true cause and mechanism of the sneezing fits brought about by the photic sneeze reflex. Sneezing occurs in response to irritation in the nasal cavity, which results in an afferent nerve fiber signal propagating through the ophthalmic and maxillary branches of the trigeminal nerve to... |
Why did some Czechs had to leave Sudetenland and some could stay after Munich agreement? | Without knowing your family history or anything it could have just been your Austrian last name.
It wasn't an exact science; so when the Bureaucrats went through the lists it could have been as simple as "Novák.. has to go. Müller... can stay" When actually Novak might have spoken primarily German, and Muller spoke Czech. I know it's not as simple as that, but Czech was so mixed that any census couldn't have been 100% accurate. | [
"The Czechoslovaks were dismayed with the Munich settlement. They were not invited to the conference, and felt they had been betrayed by the United Kingdom and France. Czechs and Slovaks call the Munich Agreement the Munich Diktat (; ). The phrase \"Munich Betrayal\" (; ) is also used because the military alliance ... |
how did the internet grow to be the way it is today? | WARNING: What follows is a layman's understanding and may be totally wrong. I was only half paying attention during my IT lecture.
The distinction between the WWW and the Internet is often missed, but is an important distinction to make. The World Wide Web is the thing we use day to day, but it is enabled by the internet. The Internet is the connection of a bunch of computers so that information can be transferred from one to the other. The WWW is the configuration of ISPs, servers, and personal computers through which HTML files (webpages) are transferred.
The role of the internet is that rather than having to create a connection between any two computers, you can connect both to the internet and they can exchange information rather like giving a letter to a mailman rather than handing it to its recipient.
The WWW consists of a bunch of servers, or buildings full of computers with tons of storage space and direct connections to all of the other servers. ISPs sell you a connection to one of these servers, from which you can connect to all the other servers and therefore any computer you want. | [
"In 1993, the release of the Mosaic web browser made access to the World Wide Web possible (prior Internet services like Usenet, Gopher, FTP, etc existed but HTTP was the new invention which triggered this growth). Internet use increased as a result of the reduction of the \"digital divide\" and advances in connect... |
why does turning canned air upside down spray cold liquid? | At high pressure, gas can turn into a liquid, regardless of its temperature. Since liquid gas is a lot denser than normal gas, you can put more into the container. As a bonus, liquid gas tries to turn into normal gas if it's exposed to lower pressures (like normal air), so you can just put liquid gas in a can with a valve, and it will come out of the valve really fast without a pump. If you fill the can part way, it will boil off until the gas above the liquid gets to a high enough pressure to keep the rest of the liquid liquid. The liquid sits on the bottom of the can, so if you flip it upside-down, you force out the liquid instead of the gas (which sits on top).
The reason why it is cold is because expanding gas gets colder as it expands, and the liquid itself boils, removing more heat from itself and its surreoundings. (think about a pot of boiling water; you have to keep adding heat in order for it to boil)
Some more non-ELI5 reading about why the liquid and gas behave this way:
[_URL_1_](_URL_1_)
[_URL_0_](_URL_0_) | [
"Canned air can be used for cleaning dust off surfaces such as keyboards, as well as sensitive electronics in which moisture is not desired. When using canned air, it is recommended to not hold the can upside down, as this can result in spraying liquid on to the surface. The liquid, when released from the can, boil... |
Why have we not seemingly seen advances in audio technology to the extent we have seen advances in visual technology? | Precisely because sound *is* the air being vibrated.
There's been advances in how the electronics and processing works, there's been advances int eh design of the cones, and how the drivers operate. But ultimately speakers are able to reproduce sound to a degree where it is nearly indistinguishable for the original recording. | [
"Acceptance of innovative technologies can be improved by providing non-emotional and concise information about these new technological processes methods. The HighTech project also suggests that written information has a higher impact on consumers than audio-visual information.\n",
"After the use of training film... |
the rna world hypothesis | Currently: DNA- > RNA- > protein=functional enzymes
DNA codes for proteins that are enzymes that do things in your body such as copying DNA.
As it so happens, RNA can perform both functions: holding information and acting as an enzymes.
The RNA world hypothesis is that RNA was the first biopolymer and performed both as an enzyme and as a template for making more copies of itself. Later DNA was evolved as a more stable information carrier and proteins as better (more diverse/stable/more modes of regulation) enzymes. | [
"The RNA world hypothesis is still under consideration, with chemist Steven A. Benner and physicist Paul Davies supporting it in a chapter of the book \"Frontiers of Astrobiology\" published in 2012 by the Cambridge University Press, in the chapter \"Towards a Theory of Life\"\n",
"The RNA world hypothesis descri... |
What is the earliest written record in Europe? | [The Minoan Culture had writing around 3000 BC.](_URL_0_) | [
"The tablets are the earliest written documents found in Britain, dating from 50 to 80 AD in the early Roman period. Notably, these tablets predate the Vindolanda tablets, which were previously the earliest writing examples found in Britain, dating to 100 AD or later.\n",
"The oldest known document is the poem \"... |
how would synthetic meat be better than normal meat environmentally? | [Yes](_URL_3_). [Immensely](_URL_1_).
How, exactly? Well, let's take a cow. There's a lot of parts of a cow that aren't used for meat. The cow has to live for a few years, eat, grow, walk around, expel waste, all that jazz. That just eats up time and energy.
In a lab, that time gets [cut down](_URL_0_) (5 oz in \~ 2 hrs). Every bit of meat that you grow can be cooked and eaten directly - minimal processing needed.
Right now, it takes [10 lbs of feed and 8 gallons of water](_URL_4_) per pound of beef. In a lab, that gets cut down to [0.1 gallons per pound](_URL_2_) (if I did the math right) (I couldn't find numbers on feed). Cows are usually fed grain or corn, so that's less crops dedicated to livestock, and thus (maybe) less farms. Less cows expelling methane and carbon dioxide. Overall, less everything. Except meat. Lots of meat. | [
"\"Artificial meat stops cruelty to animals, is better for the environment, could be safer and more efficient, and even healthier. We have a moral obligation to support this kind of research. It gets the ethical two thumbs up.\"\n",
"In addition to the prevention and lack of diseases, and lack of the use of antib... |
if coca-cola's recipe is a trade secret, what would happen if someone reverse-engineered it? | Exactly what happened when someone did - nothing.
Coca-Cola is not about the flavor. It would not be difficult to replicate Coca-Cola - although one known ingredient, the coca leaf extract, flavors from the plant that cocaine comes from, isn't available to anyone else because of drug laws. Coca-Cola is about the brand. A cola that tastes exactly like Coke couldn't compete with the Coke brand. | [
"Sanders' Original Recipe of \"11 herbs and spices\" is one of the most famous trade secrets in the catering industry. The recipe is not patented, because patent law requires public disclosure of an invention and provides protection only for a strictly limited term, whereas trade secrets can remain the intellectual... |
why don't some people react to pepper spray? | They have special eyes. | [
"Pepper spray is one non-lethal weapon alleged to have been misused by American police. In two incidents in California in 1997, police swabbed pepper spray directly into the eyes of protesters. Amnesty International condemned these actions, and claimed that they were likely a violation of the 1984 United Nations Co... |
draining the swamp | a term used by Donald Trump during his campaign (not sure if he actually started it or his supporters did) as a catchphrase for his statement that he would get the big business influence out of washington.
On that note, he's not wrong, there **are** a lot of people in the government who either are from or have ties to large corporations, banks etc, creating concerns about conflict of interest and that they're likely tipping the scales in their own company's favor.
However, he's come under fire recently for cabinet choice his critics say also have big business ties. To my memory he included Exxon Mobil's CEO as one of those picks, which critics have been all over. | [
"With regard to tactics, the terms \"drain the water\" or \"drain the swamp\" involves the forced relocation of the population (\"water\") to expose the rebels or insurgents (\"fish\"). In other words, relocation deprives the aforementioned of the support, cover, and resources of the local population.\n",
"While ... |
why are movies still released in theaters? | Because going to the theater is an experience. You go with a group of people, you are watching a screen much larger than you could ever own with a sound system far superior to what you could ever own. Yes you can watch the movie online in your home, or buy it on Blueray or via your cable but you cannot replicate the movie theater experience unless you are wealthy enough to build your own theater. | [
"Theatrical [release] is over for about 90 per cent of any film made anywhere in the world. You just have to look at what's released in cinemas now to understand that, but we are still compelled and forced to release every Australian film that gets made to give it a theatrical release, because of the way things are... |
Liquid nitrogen excessive boiling before critical temperature? | This is related to the transition between different modes of two-phase heat transfer. Initially, the temperature difference between the copper surface and the surrounding liquid is ~300 K, so a film of evaporated nitrogen gas envelops most of the block and insulates it thermally, making the rate of cooling slow. This is known as *film boiling*.
-
As the copper block cools down, the temperature difference decreases, and more of the liquid is able to make direct contact with the copper surface. Nitrogen still evaporates at the copper surface, but in the form of individual vapor bubbles (much like the steam bubbles that form when simmering water). This is known as *nucleate boiling*, and is typically associated with a higher rate of heat transfer (faster cooling) than film boiling, unless the temperature difference is becoming very small.
-
Somewhere between film boiling and nucleate boiling, there is a regime known as *transition boiling*, which is associated with very high rates of heat transfer, and violent boiling. This is the loud sizzling that you will hear as the copper exits the film boiling regime.
-
All of these phenomena are analogous to those that can be observed when a [water droplet contacts a frying pan or hot plate](_URL_0_) (where the hotplate is the equivalent of the copper block, and the water droplet is the equivalent of the liquid nitrogen). If the initial temperature difference is sufficiently large, then the droplet will be relatively unaffected by the hot surface, as it skitters around cushioned by an insulating layer of water vapor (the so-called [Leidenfrost effect](_URL_1_)). The water droplet will eventually heat up (thus reducing the temperature difference between the liquid and the solid), and when it reaches the transition zone, there will be a loud sizzle as the droplet finally makes contact with the pan.
-
---------------------------------
-
**PSA:** Remember to observe safety precautions when working with liquid nitrogen: Wear safety glasses plus face shield, and use an oxygen monitor if available. | [
"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... |
Why do some materials, like water, do a really good job of blocking nuclear radiation, but allow light to pass through practically unhindered? | So, first, there are several types of radiation you might get from a nuclear reaction. Alpha, beta and gamma radiation are helium nuclei, electrons, and high energy photons respectively. It is easier for heavier (larger, slower) radiation to interact with any solid or liquid matter you put in their path, so Alpha and Beta radiation are typically less penetrating. Anecdotally, I think your cardboard would stop at least alpha radiation, if not beta. Gamma ray photons are harder to stop because they have a smaller cross section for interaction, but with enough mass in the way you can do it. So, to stop gamma radiation you want high density materials to put in the way(more atoms per cross sectional area), so there is a greater chance of interacting with the atoms in the shield material. Thus lead is a great material for this. Water is not especially dense compared to lead, but is much more dense than air, and can fill whatever volume you have, so it might be easier to shield with a lot of water, than a lot of lead. That said, I don't believe the water in a nuclear reactor is particularly good at shielding; it is there to transfer heat away from the reactor and to be converted to steam to drive a turbine.
Stopping visible light is all about whether there are atomic/molecular energy transitions which will absorb or scatter that particular wavelength of light. So you get a variety of materials that respond to light differently; water or glass being fairly transparent, and cardboard opaque. Gamma radiation is also light, but is high energy, and therefore small wavelength, so it interacts with solid matter less readily than visible light does (whose wavelength is much closer to the size of a typical molecule). Thus, gamma rays tend to penetrate more deeply into materials than visible light does. | [
"Radiation can have harmful effects on solid materials as it can degrade their properties so that they are no longer mechanically sound. This is of special concern as it can greatly affect their ability to perform in nuclear reactors and is the emphasis of radiation material science, which seeks to mitigate this da... |
where does energy 'go' when it is used by a living thing? | When you eat, you absorb the carbs, proteins etc. When you run, these are broken down in order to give you energy to run. That energy was spent in moving your body from one place to another - it gets transformed into kinetic energy and potential energy and also produces body heat. In a nutshell as you have learnt energy cannot be created or destroyed. IT just transforms from one form to another. | [
"In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object. Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule,... |
the byzantine generals problem. | The Byzantine Generals Problem is a model for communication. It uses some number of players ("Generals") who have to come to a consensus. However, they are limited in how they are allowed to communicate--they have to send messages by courier, but the couriers may get captured (i.e. they never deliver their message). Also, couriers take a certain amount of time to deliver their message.
Thus, the challenge is: what messages do the generals send in order to coordinate an attack? They must all know the time of the attack and they must all be certain that the other generals also know the time of the attack, and that the other generals know that they know that the other generals know the time of the attack, and so on. Various versions of the problem have different numbers of generals (anywhere from two to thousands or more) and different requirements of how many generals must be certain of an attack time (typically all of them, but sometimes this requirement is relaxed). Some versions of the problem also introduce generals who intentionally send out incorrect information.
The most obvious solutions turn out to be not so good. Let's assume two generals and they must both agree. One general could send a courier saying "we attack at dawn," but maybe that courier gets lost, so he requests the other general send back another courier as an acknowledgement. However, *that* courier could get lost, meaning that the second general has received the message to attack at dawn while the first general doesn't know whether or not the message was received. The first general doesn't know whether to attack or not, so this solution is no good. The first general could, instead, send 1000 couriers at once and request 1000 acknowledgements back, but that only changes the odds--he can never be 100% certain that they don't all get lost (and even if they don't get lost the second general doesn't know that without a second round of confirmations, this time going from General 1 to General 2).
In many forms the Byzantine Generals Problem is proven to be unsolvable--there is no finite set of messages that gives 100% assurance that everyone knows when to attack. There are solutions to various other versions of the problem, though. | [
"The same authors helped to popularize the interactive consistency problem in their 1982 paper, \"The Byzantine Generals Problem\", which presents it in the form of a colorful allegory proposed by Lamport. In the allegory, the computers are replaced by Byzantine generals who needed to coordinate the timing of an at... |
What would happen if the poles switched? | If by every couple of years you mean every couple of tens of thousands to millions of years, then yes, the [polarity of the earth's magnetic field definitely flips occasionally](_URL_0_). The image on that page shows the geomagnetic timescale with black bars indicating 'normal' polarity (the orientation of the field now) and the white bars indicating 'reversed' polarity. We are currently within the Brunhes normal period with the last full switch of the magnetic field occurring 780,000 years ago. The geomagnetic timescale has been constructed by measuring the orientation of magnetic minerals in rocks (that align to the orientation of the magnetic field at the time that they were deposited/cooled depending on the rock) that can be dated independently through geochronologic methods (e.g. Uranium-Lead, Potassium-Argon or Argon-Argon, etc).
There is little evidence that these flips are catastrophic to the biosphere under normal circumstances. If you look at the wikipedia article from above, you can see that there has been a decent amount of speculation that there may be a causative link between mass-extinctions and reversals, but in many cases it's hard to demonstrate. There have been some hypotheses presented [linking particular extinctions to particular reversals, with the causative mechanism being decreased atmospheric oxygen caused by decreased protection of the magnetic field from the solar wind](_URL_1_), but at this point, this seems like a somewhat special case (i.e. we have plenty of mass extinctions that seem to have nothing to do with reversals and plenty of reversals that don't seem to correlate with any significant extinction).
Obviously there has not been a reversal during the era of modern technology, so there remain some questions of how a geomagnetic reversal would play out today as magnetic field fluctuations can do strange things to some equipment (e.g. the power grid). Not being an expert on electronics and how they might react, I won't speculate, but you can find predictions of everything from ['it will be fine'](_URL_2_) to ['it may cause significant disruptions in some technology'](_URL_3_). A lot of unknowns remain, like the duration of reversals. Some evidence suggests they are very gradual taking 1,000s to 10,000s of years to complete, but in other cases they have occurred very rapidly (several decades). The details will matter in terms of how this might influence life on earth. | [
"Owing to motion of fluid in the Earth's outer core, the actual magnetic poles are constantly moving. However, over thousands of years their direction averages to the Earth's rotation axis. On the order of once every half a million years, the poles reverse (north switches place with south).\n",
"The precise locat... |
Did the Knights Templar really commit heresy in their initiation rites? | There are three broad theories about the confessions of certain Templars obtained by ~~Louis~~ Philip IV:
1. The confessions were extracted by putting words into the mouths of the leaders of the tortured, or confessions were otherwise falsely recorded.
2. The basis of some confessions were found in actual acts but manipulated to the required ends of blasphemy and heresy accusations. Some scholars have suggested for example that accounts of 'blaspheming' of Christ were actually tests of loyalty within the order and not actual blasphemy, devil-worshipping, etc.
3. The Templars were in fact blasphemers, heretics and devil worshippers.
Historians work with the first and second theories and argue back and forth through evidence about it. What is important and fascinating is how these stories found root in soil so fast. This after all was the century of persecution of heretics, of the decline from the heights of Papal power in the previous centuries, and the beginning period of the formation of an idea of the witch as devil-worshipping, anti-Christian cult. The accusations against the Templars were becoming common tropes.
The third theory is an utterly compelling but untenable fiction, ultimately fit only for /r/conspiracy.
edit: some French king or other | [
"The original Knights Templar, founded around 1119, had been a crusading military order, that, at some time, had established financial networks across the whole of Christendom. In 1307, King Philip IV of France mounted a \"slanderous campaign\" to strip the Order of its economic and political influence. The Templar... |
In the sixteenth century, how did understanding of the Protestant Reformation evolve among Catholic leaders? Did they go from seeing it as a temporary split, over time, to a more permanent schism? | Oh man, you’re gonna love [this](_URL_0_) post by u/sunagainstgold. He talks about what made Martin Luther so special an what exactly people at the time were expecting to happen. | [
"The Reformation swept through Europe during the 16th century. The excommunication of Protestants by leaders of the Roman Catholic Church ended centuries of unity among Western Christendom. The religion of an heir to the throne became an intensely important political issue. The refusal of Pope Clement VI to grant a... |
How accurate is this representation of Viking combat? | Could you post the video? | [
"The battle is included in the 's expansion 'Viking Conquest'. The battle might take place before its historical date though, depending on player's choices. During the battle, the player character will clash against the Dane invaders aided by the West Seaxe army, and take revenge on Sven Bull Neck, a fictional Viki... |
How much does Eric William's *Capitalism and Slavery* (1944) hold up? | (1/2)
The short, and profoundly unhelpful answer, is that it depends entirely on who you ask and what you mean by "hold up", and for what reasons you're interested in Williams' ideas. The ideas presented in *Capitalism and Slavery* are today referred to simply as 'the Williams thesis' by scholars of transatlantic slavery and the British Empire, and they have been debated non-stop pretty much since the moment Williams first published the book, and there has been a resurgence in interest around the Williams thesis among new scholars in the last few years. Part of the problem in assessing Williams' legacy is that many scholars misunderstand the context in which he himself was setting out his ideas, and miss the fundamental point that he set out to make at a time when the modern historical professional was still in its relative infancy.
At its most basic, the Williams thesis set out in *Capitalism and Slavery* essentially argues that the development of modern capitalism in Western Europe and the United States was dependent upon the experience of transatlantic slavery. Williams makes the argument that slavery was a system that allowed British elites to create vast sums of wealth that were simply not possible prior to the colonisation of the New World, whilst also creating the foundations for an infrastructural network that would transform the scope, speed and efficiency of both interregional and international trade. In the Williams model of the development of modern capitalism, the vast profits from the slave trade in the Americas created the capital necessary to invest in new technologies and means of production at home in Britain, spurring on the industrial revolution and making possible the development of the modern capitalist economy.
Williams never really comes to a concrete conclusion about the full nature of the relationship between slavery and capitalism - sometimes he describes slavery as capitalistic and at other times his ideas clearly argue it is wholly distinct from capitalism - but in essence, he sees the transatlantic slave trade as a proto-capitalistic phenomenon, with some elements of capitalism already present in slavery and others yet to emerge. But he also argues that we cannot look at the colonial system as it existed in the period of transatlantic slavery as truly capitalistic because it depended upon the heavy warping of market forces to sustain itself. For Williams this was demonstrated best by the explosion in trade and commerce that ultimately followed American independence after an initial period of adjustment, and he holds that this was not lost on contemporaries in Britain when they were considering what to do with Caribbean colonies who (in his mind) were increasingly struggling to compete with the United States. In particular, he cites anger from British industrialists and merchants that the industrial revolution and Britain's Imperial project abroad had led to an explosion in competitive markets to sell goods to abroad, but public policy protecting the monopolies of Caribbean planters impinged their ability to cut the costs of production or seek out alternative sources of raw material.
But in making this case, Williams was not necessarily trying to focus too much on identifying at what point slavery gave way to modern capitalism. Rather, *Capitalism and Slavery* is better understood as a refutation of a popular narrative - one which we still see in our schools today in the UK - that the British nation abolished slavery for entirely moral reasons, driven by the demands of a British public who were horrified to start learning of the brutality of the slave trade and conditions in the Caribbean. Eric Williams was trying to make the point that rather than public pressure, moral outrage or the evolving political sentiments among the elite in Britain as a result of ideas about freedom and democracy, the abolition of slavery was only made possible by the cold, methodical calculation that it had become a net drain on the British economy. In essence, the same capitalists who decades earlier had been turning to slave owners to find investors in their grand projects and schemes were now looking on those investors with contempt for their protected, privileged position. Williams argues that the Caribbean in this period was in terminal economic decline, unable to compete with a much more modern and also industrialising United States economy as well as new competitors in India and other British colonies, and that the profits of industry were now so self-sustaining and secure the capital of the Caribbean plantocracy was largely going to waste.
So there are really two very closely linked but subtly and meaningfully distinct ideas being explored *Capitalism and Slavery*. One is about the relationship between slavery and capitalism as systems; it would be uncharitable to say that Williams deals with this subject primarily by accident, because he was a man well versed in these kind of theoretical and political issues But it is not fundamentally why he was writing the book. He does come to the conclusion that the wealth created by slavery was an essential ingredient in the development of the modern capitalist economy but he never really gets into the ins and outs of any kind of higher theory of what that relationship looks like precisely, and he didn't set out to. *Capitalism and Slavery* has been imagined by some to have made a kind of Marxist critique of modern capitalism, but although he was influenced by some Marxist ideas via the likes of his alternating political ally-and-rival C L R James, Williams was fundamentally pragmatist who had little time for ideological frameworks or being restricted to a single way of understanding the past. The second theme - and the idea that Williams was really trying to press - is the notion that slavery had become economically unsustainable by the 19th century, and that this made inevitable its destruction at the hands of industrialists and their advocates once the economic decline of the region became apparent. Williams was above all setting out to disprove the idea that the abolition of slavery could have been motivated by anything other than the calculated, economic concerns of the capitalist elite, although he does take care to stress that he is describing broad patterns rather than ruling out altruism on the part of every individual or group.
The question of how the Williams thesis holds up then depends partly on how you want to use his work and his ideas to better understand slavery. There have really been two interwoven debates raging around the ideas that Williams advanced since the 1940s: one about the nature of the relationship between slavery and capitalism, and one about the nature of the economy in the British Caribbean. The former is larger and more well known because it's an area of work of profound interest to a whole new generation of scholars and one that has seen quite a lot of movement in the last few years, whilst the latter is a smaller, quieter debate which is concerned more with the practicalities of *Capitalism and Slavery* as an economic study of conditions in the region up until abolition in the 19th century and to what extent Williams' ideas about humanitarian vs economic concern stand up to scrutiny. The former is usually what we mean these days when we talk about the debate around 'the Williams thesis', even though I'd argue it's fairer to Williams himself to use that title for the second debate that he was more intentionally contributing to.
To make matters even more complicated, it is probably fairest to say that on both debates scholars have come to the conclusion that Williams was both right and wrong in his analysis depending - again - on what aspects you want to focus on and what you think the most important parts of 'the story' are.
In Caribbean studies there is now broad agreement that although *Capitalism and Slavery* does correctly identify some very real structural concerns for the long-term economic health of the British Caribbean in the run-up to the abolition of slavery, he was off the mark in assuming this meant that the institution of slavery was in terminal decline or would inevitably crash the economy of the Empire without intervention. The evidence we now have instead points broadly to a regional elite who were slow to adapt to changing economic circumstances but who were nonetheless adapting, and beginning to re-energise the institution of slavery in the Caribbean just as abolition was imposed on the colonial elite. It has also been shown that Britain's anti-slavery commitments were not pursued without cost, and the abolition of the slave trade in particular has been identified as shaving a not insignificant sum from national income in Britain over several decades, whilst abolition was only made possible by the imperial government being willing to pay £20million (the equivalent to around £80billion in wealth today) to cover the cost of wealth lost by former slave owners. We also have a very rich abundance of research on the United States now that affirms the institution of slavery was most certainly not unprofitable or in decline there, and that on the contrary it was thriving and continuing to grow on the eve of the Civil War. | [
"In the same body of evidence, he notes that the fatality rate for his slaves was one in twelve, and that \"The average allowance of width to a slave is fourteen and two-thirds inches.\" Penny also argued that abolition of the trade would destroy the economy of Liverpool; \"it would not only greatly affect the comm... |
How can scientists accurately measure the populations of insects? | Look up malaise flight traps and pitfall traps. These are two common methods for collecting insects and the data gathered by them can be used to explore the incidence and abundance of the species.
I use pitfall traps to estimate the abundance of native ant species in communities that are undergoing invasion by the invasive tawny crazy ant. | [
"Researching the collections of insects provides important information that develops knowledge about ecology, human health and crops. Well-kept records aid the researcher in identifying whether there are differences in an observed specimen because of damages, treatments or deterioration. Research of the insect coll... |
How is graphite formed? | Anthracite coal is mainly amorphous (glassy) carbon, but the properties of graphite aren't due to its purity as much as its molecular structure. Amorphous carbon is full of carbon atoms making 4 bonds any which way they can, but graphite has the atoms arranged into sheets made up of a hexagonal arrangement of carbon atoms.
If you get a pure enough sample of amorphous carbon and heat it up enough in an inert atmosphere, you will begin to convert it into graphite. This is where naturally occurring graphite comes from. Give carbon enough time, heat, and pressure, and you'll get graphite (or diamond if P and T are really high). | [
"Graphite (), archaically referred to as plumbago, is a crystalline form of the element carbon with its atoms arranged in a hexagonal structure. It occurs naturally in this form and is the most stable form of carbon under standard conditions. Under high pressures and temperatures it converts to diamond. Graphite is... |
what happens to the proceeds of crime? | The police get to keep it. It's called "civil asset forfeiture", and it gets rolled into the police budget. It's been a big sticking point lately because it has been used to seize money that almost certainly was not acquired or intended to be used illegally. | [
"The Proceeds of Crime Act 2002 (c.29) (POCA) is an Act of the Parliament of the United Kingdom which provides for the confiscation or civil recovery of the proceeds from crime and contains the principal money laundering legislation in the UK.\n",
"BULLET::::- Killing out of greed means that the perpetrator kills... |
Has the speed of the increase in computer processing speed slowed way down? | It's true that clock speeds aren't increasing like they used to, but there's more to processor speed than clock rate. So the question is a little complicated.
**First, what is clock speed?**
A processor is made up of a lot of transistors, which in digital circuits (like a CPU), work like tiny switches. These switches are combined to implement operations like the AND gate. An AND gate is a logical operation that is true (i.e., ON) if both inputs are true (ON). But transistors, just like switches, take some time to go between ON and OFF. So what value should the AND gate take if one of its inputs is half-on half-off?
The solution is a clock rate. The circuit is designed so that there is a clock signal, and every transistor is **guaranteed** to be on or off at each tick of the clock. The AND gate is then designed to take the value of its inputs at the beginning of the clock tick.
So the clock rate has an immediate impact on processor speed. The faster the clock ticks, the less time between transistor states, the faster the CPU processes instructions.
**So why are processor speeds no longer increasing?**
Well, it has to do with circuit design. If you take a CPU and just start increasing clock speed, eventually you'll run into problems, because the transistors *won't* have time to switch. You can force a transistor to switch faster, at the cost of more heat. But it turns out that this isn't *really* the problem. If you're building a new CPU, you can use fast transistors that switch fast enough, if you want. The *real* problem is electromagnetics.
When designing most circuits, you think of the circuit as following certain rules. Now, there's Maxwell's equations (and quantum electrodynamics for the semiconductors) which describe what's going on very precisely, and very accurately. Unfortunately, these are very complicated. It's very difficult to design a circuit using Maxwell's equations.
Fortunately, we have approximations. We think of a circuit in terms of voltage, and current flow, ohm's law, Kirchoff's law's and such.
But they're *good* approximations, most of the time. They're good approximations, good enough for circuit design in general.
These approximations largely depend on the fact that the speed of light is mindbogglingly fast. Unfortunately, 'mindbogglingly fast' is a subjective term. It turns out that in circuits with gigahertz clock speeds, 'mindbogglingly fast' becomes only 'somewhat fast.'
What's going on is that the electrical signals that the circuit laws deal with are really electromagnetic waves. When the wavelength is very long, you don't need to worry about it: the approximations hold. But in the gigahertz range, the wavelength is getting to be the same size as your circuit. At this point, those tidy approximations start to break down.
Now, if you want to design a circuit, you can't use the traditional digital design techniques, and you enter the domain of microwave circuits. There are *much* harder to work with, and it turns out to not be worth the bother.
**Parallelization**
So you can't just make clock speeds faster, it makes your circuit too hard to design. So instead of doing more sequentially, you do more *in parallel*.
If you take a modern CPU like a Core i7, it'll be a lot faster than an old Pentium 4, even if they're running at the same clock rate. There's three reasons for this.
The first is, as you point out, multi-core. A Core i7 has many cores on it, all working in parallel.
The second is that a single Core i7 core is doing a lot more concurrently. In a single clock cycle, it does more work than a Pentium 4 does. We say that it executes more Instructions Per Clock.
Finally (and very importantly), the Core i7 spends less time waiting around. A lot of processor time is wasted in a CPU because the chip is waiting for some information to arrive from somewhere else. The Core i7 is a lot smarter about how it deals with data and as a result it doesn't spend nearly as much time waiting.
Now, accomplishing these three tasks (especially the last two) is conceptually a lot more complicated than simply increasing clock rates. It's also easier to convince people that a new chip is faster when you can simply point to a number on the packaging. So back when it was comparatively easy to increase clock speeds, that was a primary focus of chip designers. | [
"CPU speed improvements slowed significantly partly due to major physical barriers and partly because current CPU designs have already hit the memory wall in some sense. Intel summarized these causes in a 2005 document.\n",
"Overall productivity growth was relatively slow from the 1970s through the early 1990s. A... |
how is that alcohol is not good for flesh wounds? | First, alcohol is a blood thinner and can lead to excessive bleeding from wounds.
Second, it is a disinfectant but it's rarely ever drank by itself and the sugars feed bacteria that can get into the open wound. It also works by drying out bacteria and your cells essentially killing them making wound repair with long term exposure harder. | [
"BULLET::::- Alcohol – Alcohol consumption impairs wound healing and also increases the chances of infection. Alcohol affects the proliferative phase of healing. A single unit of alcohol causes a negative effect on re-epithelialization, wound closure, collagen production and angiogenesis.\n",
"Alcohols, in variou... |
if all 7.4 billion humans were to drop dead right now, how many fossilized skeletons would we leave in 65 million years, and what evidence of our civilization would there be? | I can't answer the first part, but there are a few Shows you can watch they did this topic.
[Aftermath: Population Zero](_URL_1_) was on the National Geographic channel. They did an overall View of the planet.
Their final statement:
> (25,000 years A.H)
Earth enters a new Ice Age, and glaciers expand south covering most of the Northern Hemisphere. The last traces of New York City are completely erased. Most species however adapt and thrive; sea lions, ducks, fish, wolves, horses, cattle, elephants all adapt alongside many other species. However, evidence left by Moon exploration missions and certain plastic items will survive intact for not only thousands, but millions of years after mankind has vanished. They will be the last legacy of the human race.
[Life After People](_URL_0_) was on the Discovery channel.
This series broke it down a little: Structures, Chemicals, Roads...etc. The first episode did talk about the bodies and what happens to them. Its been a while since I've watched it, but I might have some more information. | [
"Should the human race become extinct, then the various features assembled by humanity will begin to decay. The largest structures have an estimated decay half-life of about 1,000 years. The last surviving structures would most likely be open pit mines, large landfills, major highways, wide canal cuts, and earth-fi... |
how are engineers able to build subway tunnels under already built infrastructure? | There are multiple ways that they can do it. Here in Boston where I live they finished the [Big Dig](_URL_1_) a few years ago. Over the course of roughly ten years they consolidated all the utilities through a corridor of the city and then sank an entire elevated highway underground. It had to go above and below various obstacles like a subway tunnel, a waterway, and Boston Harbor itself.
The main corridor of the sunken highway, I-93, was built in multiple sections. In parts of it they simply closed down the ground-level street for a few months, dug a 100 foot deep pit, built the tunnel, then filled the hole back in.
In another part where they had to dig directly under the existing elevated highway they first sunk steel girders 100 feet down to the bedrock, filled the area around them with concrete, then supported the existing highway on top of that while digging out the dirt and building the tunnel underneath.
At one spot they had to build the tunnel underneath an existing subway station that was itself underneath a very busy surface road in the middle of downtown Boston. To do this they first dug two vertical shafts to below the level of the subway station. They then dug horizontal tunnels underneath the station, supporting them with concrete. From those tunnels they dug hundreds of tiny shafts and filled them up with concrete. Eventually they formed it all into a complete set of concrete walls that formed the new tunnel. If you scroll close to [the bottom of this page](_URL_2_) you can see a series of graphics that show how it was done.
Another section of tunnel had to be built under multiple train tracks just outside one of Boston's main train stations where thousands of commuters pass every day. The soil under the train tracks was pretty soft so they had to figure out a way of building this tunnel without making the tracks sink into a sinkhole or anything like that. What they did in this case was to sink hundreds of pipes into the ground and then injected freezing water into them in order to freeze the ground solid. They then dug a pit on one side of the tracks and built an entire tunnel section there. They then used giant hydraulic jacks to pull the tunnel section underneath the tracks as they slowly dug out the frozen dirt underneath them. [Here's a page](_URL_0_) that describes that process.
Although not used in Boston, another typical way of building tunnels is by using a tunnel boring machine (TBM). A TBM is basically a crawling machine that can dig out dirt or rock in front of it and then immediately seal the circular hole it creates with reinforced concrete. | [
"Other challenges included existing subway tunnels crossing the path of the underground highway. To build slurry walls past these tunnels, it was necessary to dig beneath the tunnels and to build an underground concrete bridge to support the tunnels' weight, without interrupting rail service.\n",
"Underground tun... |
why are graves 6ft deep? | That was found to be the depth necessary to prevent animals from picking up the scent and digging for food. | [
"The depth of the graves varied, although most were around 0.36 metres deep below the 1950s soil level. The deepest was below, while the shallowest were below the modern surface, indicating that the Anglo-Saxon ground level was undoubtedly higher. The sizes of the graves also varied, with the smallest being , and t... |
Pretend I'm a fish and get swallowed whole by a shark... How long do I live inside the shark/what ultimately kills me? | > Most sharks swallow their food whole or bite it into relatively large pieces. Sharks have U-shaped stomachs that use very strong acids and enzymes to dissolve most of what is eaten.
Doesn't sound like a very long time.
Source: _URL_0_ | [
"Digestion can take a long time. The food moves from the mouth to a J-shaped stomach, where it is stored and initial digestion occurs. Unwanted items may never get past the stomach, and instead the shark either vomits or turns its stomachs inside out and ejects unwanted items from its mouth.\n",
"The shark chases... |
Does an equation exist which is used to calculate the melting temperature of compounds? | IIRC You can calculate the boiling point of a compound via the Clausius-Clapeyron relation, so long as you know the latent heat of vaporization. (_URL_0_) From my humble opinion (~6 years of physics) I would say classical thermodynamics is a very empirical field (trying to match experiments, find working relations, might be missing fundamental 'why' for the sake of 'well it works') and it was really the exploration into the 'why' which birthed Quantum Mechanics. A detailed course in Condensed Matter (aka solid state physics) will eventually describe a manner in which to calculate the heat capacity (dU/dT) in a material given its lattice structure, but that's actually the most detailed explanation of a theromdynamic property I've seen in the context of your question. It's a fairly long winded story which doesn't really answer your question so I won't drag on. | [
"The previous paragraph shows how melting temperature and thermodynamic parameters (Δ\"G\"° or Δ\"H\"° & Δ\"S\"°) are related to each other. From the observation of melting temperatures one can experimentally determine the thermodynamic parameters. Vice versa, and important for applications, when the thermodynamic ... |
Is there a reason that truck trailers transporting liquids have a cone shape at the back of the container? | You'll probably need to clarify to get the answer you're looking for. Can you provide a picture of what you're talking about?
Most [tanker trucks](_URL_0_) are round or elliptical in cross-section, and they usually have a flat or domed rear closeout. The shape is dictated by the pressure of the fluid inside, but generally they follow design guidelines for pressure vessels in order to maximize strength for a given weight. Where is the cone? | [
"BULLET::::- Container trailers are standard intermodal \"boxes\" that can be fitted with a dolly (wheel truck) and front stand; they can then be used in a standard tractor-trailer combination. The containers are also stacked on ships and used as railroad boxcars.\n",
"The second aggregate container on the traile... |
why do cops put white towels on the shoulders of saved victims in crimes scenes on the movies? | I don't know about white towels, but ambulances have foil heat blankets that are used to treat hypothermia and are also used for shock. One of the symptoms of shock is cold, clammy skin, so presumably these blankets, which can trap body heat, help with that. | [
"Since the Terrible Towel's debut, teams have used similar gimmicks, mainly using white towels (or towels with the team's colors) and giving them out to fans. The main time teams give rally towels is during league postseasons. Towels have gained much popularity as distractions to visiting players. Teams that use ra... |
how do big development teams such as bethesda work on huge games like elder scrolls and fallout for multiple years without a single leak from within the huge dev team? | The threat of being sued into oblivion (no pun intended) for violating a non disclosure agreement, losing your job, and being known as untrustworthy in the industry is enough for most people. Game development is often pretty compartmentalized so it wouldn't be too hard to track down people behind the leaks since only certain groups would have access to different sets of information. | [
"Since its foundation, Bethesda Game Studios has principally been involved in the development of role-playing video games with their \"The Elder Scrolls\" and \"Fallout\" series for consoles and personal computers, almost all of which have been commercially and financially successful.\n",
"The Elder Scrolls Renew... |
has all the nuclear radiation emitted since 1945 affected human genetics at all? | We're exposed to far more natural radiation than to radiation from nuclear weapons, at least on average. The reason is that there are radioactive substances in the ground, and that there is radiation coming from space.
[Here](_URL_0_) is a useful infrographic that shows pretty well how much radiation we receive from what sources. You can see there that the radiation received even by inhabitants of Fukushima is far lower than what the average person receives on a yearly basis from natural sources (Bottom left of the green box). | [
"The genetic effects of radiation, including the effects on cancer risk, were recognized much later. In 1927 Hermann Joseph Muller published research showing genetic effects, and in 1946 was awarded the Nobel prize for his findings. Radiation was soon linked to bone cancer in the radium dial painters, but this was ... |
Why do you get an immediate jolt to your heart rate when you think you're in danger? What purpose does this serve? | The Sympathetic Nervous System (SNS) is responsible for the "fight or flight" response you describe. SNS innervation to the heart increases heart rate and the amount of blood pumped to the body. It also increases your alertness, releases chemicals like adrenaline, diverts blood to vital organs and muscles, and generally prepares you for a life-or-death situation.
The Parasympathetic Nervous System does the opposite. Its effects are to "rest and digest". | [
"The symptoms of a panic attack may cause the person to feel that their body is failing. The symptoms can be understood as follows. First, there is frequently the sudden onset of fear with little provoking stimulus. This leads to a release of adrenaline (epinephrine) which brings about the fight-or-flight response ... |
how do you "create" internet? | Well, you seem to be talking about two different components of "internet."
The actual content you access is nothing more than data on a computer somewhere. Let's say I create a text file on my computer and call it "Information.txt." Then, you use some software on your computer to access that information, maybe by typing "non_troppos_computer/information.txt" into some strange web browser that would accept that kind of input. Using the internet is almost exactly the same, except instead of a text file, it's every type of file you could imagine.
Though, you also seem to be referencing bandwidth, and how bandwidth is created. The answer is as simple as it seems; all of the data that goes from "the internet" to your computer travels through a series of cables. As a simplified example, data might go from its computer of origin, through a Cat5 cable, through a router, through a modem, through a fiber optics line that runs down the street, into your modem, into your router, into a Cat5 cable, into your computer. In the real world, though, data travels thousands and thousands of miles, so instead of a simple fiber optic line running down the block, you have an absurdly complicated network of fiber optic lines, sometimes running through data centers (maybe a facility owned by your ISP) which then route data to your computer. ISPs upgrade their bandwidth (how much internet they can send you at a time) by upgrading their cables and hardware to materials that are better at carrying electrical signals.
So to explain this figure that you saw that gave examples of how much 500mb of data costed around the world, it was probably estimating the cost of the infrastructure it would take to carry 500mb of data to a single user. Here in America, we have a relatively stable data infrastructure in place that carries high speed internet to a huge majority of the country. On the other end of the spectrum, though, you'd have a hermit in a shack in Zimbabwe on top of a mountain; piping 500mb of data to him, where there is no infrastructure in place, would obviously be a lot more expensive. | [
"A web project is the process of developing and creating a Web site, activities in a network which are aimed at a pre-defined goal. The network can be both accessible for everyone, as in the Internet, or only for certain people, as an intranet. The goal of Web projects is the transfer of static and dynamic content ... |
why do sone christians consider any kind of electronic implant the "mark of the beast" and what exactly is the mark of beast from a literal standpoint? | I think that the question:
* What exactly is "xxx" in a prophecy, from a literal stand point
is the wrong question.
The nature of prophecy is non-literal. It is like reading an IKEA manual and looking for prophetic symbolism. | [
"In the 2008 book \"Vintage Jesus: Timeless Answers to Timely Questions\", authors Mark Driscoll and Gerry Breshears write: \"According to Scientology, Jesus is an 'implant' forced upon a thetan about a million years ago\". In \"A Piece of Blue Sky\", Jon Atack writes \"In confidential issues, Hubbard dismissed Chr... |
To what extent did the Arabs influence the Spanish language, art, and literature? | I can only comment on architecture, but I studied in Toledo, Spain for 4 months and took a class on the art and architecture of the city. It's known as the "City of the Three Cultures" due to the Christian, Arab, and Jewish influence on life/art/culture. Muslims were not all expelled when the city was reconquered, and because of this their influence is more noticeable. I can give a few examples. You see a lot of Moorish/Arab architectural motifs, like arches with "lobes" on buildings, especially church towers.
[Example 1](_URL_1_) This is the Tower of Saint Thomas, which I wrote a paper about. You can see the rounded arches, and the "lobes" (as they are roughly translated) above the arches.
[Example 2](_URL_4_) This is the Church (former mosque) of Christ of the Light. It was recently discovered inside a newer structure and then restored. You can again see the circular arches, the lobes, and the brickwork above actually used to be a complete Arabic inscription.
[Example 3](_URL_3_) Another part of la Mezquita de Cristo de la Luz
[Example 4](_URL_2_) This is a former synagogue, now known as Santa Maria la Blanca. You can see again the arches, and the very intricate molding around the tops of the columns.
[Example 5](_URL_0_) Another synagogue, El Transito, showing the intricate arches and moldings.
So many of the older buildings show the Arab influence, in color, style, and in the various little motifs and the ways they are expressed. It's far more impressive if you can visit because you can directly compare the Arab influenced structures with the later Christian ones. You can see the differences in the components, because they all have arches, windows, decoration, etc; but it is all done in a different way. Hope that helps, I know that these same architectural influences are found all over southern Spain, this was just the extent of my knowledge. I loved that class and I'm glad I had this chance to recount it. | [
"During the Middle Ages, Literary Arabic was a major vehicle of culture in Europe, especially in science, mathematics and philosophy. As a result, many European languages have also borrowed many words from it. Arabic influence, mainly in vocabulary, is seen in European languages, mainly Spanish and to a lesser exte... |
aleph numbers....whaaat? | In short, there are different values of infinity, and some are larger than others. Very crazy, but there it is.
Here are examples of infinities: (A) the number of whole numbers, (B), the number of even whole numbers, (C) the number of fractions, and (D) the number of all possible numbers (including numbers like sqrt(2), which cannot be written as a fraction)
As it turns out, A, B, and C are all equal and are one kind of infinity. D, however, is a larger infinity.
Mathematicians determine this by trying to come up with what's called a bijection between two sets. That means every element in one set can be mapped to exactly one other element in the other set. Think of it like translating temperatures from celsius to fahrenheit - every celsius temperature has exactly one equivalent fahrenheit temperature.
As an example, consider set (A), all the whole numbers, and set (B), all the even numbers. You can pretty easily form this mapping by saying something like "b = 2 * a". Then if you took the number 7 from (A), you would get the number 14 in (B). The fact that you can form this mapping means that the infinity of (A) and the infinity of (B) are equal.
Now take set (D), every possible number. Mathematicians have proven that you cannot form a mapping from (A) to (D), because there are way too many elements in (D). That means the infinity of (D) is larger than the infinity of (A).
In aleph terminology, (A) is alpeh 0, and (D) is aleph 1.
Interestingly, anything that's aleph 0 is said to be "countable". Anything above aleph 0 is said to be uncountable, since they cannot be mapped to the counting numbers. | [
"In mathematics, and in particular set theory, the aleph numbers are a sequence of numbers used to represent the cardinality (or size) of infinite sets that can be well-ordered. They are named after the symbol used to denote them, the Hebrew letter aleph (formula_1) (though in older mathematics books the letter ale... |
zen buddhism | Because you're reading a Rinzai Zen scholar (DT Suzuki) and a Soto Zen monk (Dogen). Two sects, two schools.
Zen is a sect of Buddhism that is Mind to Mind transmission outside the Scriptures. This doesn't mean it doesn't use scriptures. It only means it's not founded on them.
When Buddha twirled a flower and Mahakashyapa smiled in silent understanding, that was "Mind to Mind" transmission. It means that the Mind of the Master is imprinted on the Mind of the Student. But it's better to say that there is only One Mind (the term Chinese Zen Masters used).
This One Mind is not thinking, it is not consciousness. This "Essence of Mind" as Hui Neng called it, is what Zen adepts try to directly witness, fuse with. It is like this: thinking is the waves, and the Essence of Mind is the ocean. So, what are your thoughts "made of"? What is their source? -
You can start your Zen journey by simply asking yourself: "What was my original face before my parents were born?" - Or, mommy and daddy were born, considering the Subreddit we're in. Anyway, the way of Zen is in the realisation that - since thinking is the waves, and the source - essence - one mind is the ocean itself, how can producing more and more waves make you realize the ocean?
Or, let's say the ultimate reality is a moon instead, reflected on the waters. You won't get it by grabbing it, by thinking; the more you "catch" it the more waves you produce. It is when you abandon discriminative thinking that the waves cease and the waters calm, and you can see the imprint of reality, the Moon reflected on your internal mirror.
That's the best I can do in this format here. | [
"The term Zen is derived from the Japanese pronunciation of the Middle Chinese word 禪 (\"Chán\"), which traces its roots to the Indian practice of \"dhyāna\" (\"meditation\"). Zen emphasizes rigorous self-control, meditation-practice, insight into the nature of things (Ch. \"jianxing,\" Jp. \"kensho,\" \"perceiving... |
When someone suffers from depression, why are memories from that time hard to recollect? | Our mind has a coping mechanism that erases memories which are too painful for us to bear. It's a very simple answer and I'm sure there is more to it than that, but it's certainly one of the reasons it is hard to recall memories from that time. | [
"Some memory issues are due to stress, anxiety, or depression. A traumatic life event, such as the death of a spouse, can lead to changes in lifestyle and can leave an elderly person feeling unsure of themselves, sad, and lonely. Dealing with such drastic life changes can therefore leave some people confused or for... |
Why did China recover from the collapse of the Han Dynasty so much better than the Mediterranean recovered from the collapse of the Roman Empire? | Well, you are whitewashing tons of complexity over a massive period of time (200 CE - 1800 CE), but in general the basics are there in your subtext.
Rice cultivation was a major part of the story, as it was key to the success of the southern states after the fall of the Han. The Cao family's wei dynasty could not fully control the south and southwest because these regions had become powerful, not entirely, but vitally due to rice.
By the Tang Dynasty (618-907) reunification, rice was a key tax staple (along with silk), and the need to keep the canal system flowing caused the Tang rulers to spend nearly as much time at Luoyang as they did at Changan. Luoyang sits about 400km east of Changan, in a much better location for Yellow river barge traffic, without the complication of the Tong pass and the wei river. The SE to NW canal carried rice industry was the lifeblood of the Tang empire, and was all that was left intact after An Lushan's rebellion (755-763). By the end of the Tang - which collapsed more due to structural weakness than climate/resource scarcity - the midieval climate anomoly was in full swing, so China saw a very short interregnum before the Song, Xi Xia, and Khitan-Liao kingdoms took over most of the former Tang territories.
At this point, the wealth of crops (2nd and 3rd in some cases) really opened up China to what would be the world's first commercial revolution. Europe at this point was also commercializing, but with less urbanization, less capital mobilization, and much less literacy.
To look at Rome specifically - Rome depended heavily on levantine/egyptian wealth - once the eastern mediterranean was cut off Rome had few resources, and could not draw on their southeast equivalent the way the Tang dynasts could. The Byzantines certainly did ok exploiting the wealth of the eastern med region - and did pretty well, but western/northern europe were screwed until the weather improved in the 9th century.
This is therefore somewhat of a climate and resources story. What crops could be grown in great enough quantity between 200-900 when the weather was poor? In the fertile crescent and Egypt, where crops were still ok, the Arabs were firmly in control by 700. Once the weather improved in the middle of eurasia and north africa no european group could easily displace them, as the crusades demonstrate. But certainly the best developed places in europe by 1200, Genoa and Venice, were so because of the eastern med. trade system.
**TL;DR** yes it was rice. | [
"The Han defeated and drove the Xiongnus west, securing the city-states along the silk route that continued into the Parthian Empire. After the decline of central imperial authority, the Han Dynasty collapsed into an era of civil war and continuous warfare during the Three Kingdoms period in the 3rd century AD.\n",... |
why do pictures of the stars from telescopes along with photos of most light sources appear to have horizontal and vertical lines through them resembling crosshairs? | The lines are called "diffraction spikes", and they are caused by light waves being interfered with by the structure or shape of the camera or telescope.
The most common one in star photographs is four spikes. Many star photos are taken with a reflector telescope, which has a mirror mounted inside it - usually on four wires or thin pieces of metal (called vanes). Starlight hitting these 4 supports bounces around and creates the spikes. Some telescopes have different numbers of mirror mount vanes, creating different numbers of spikes.
Diffraction spikes can also be caused by the non-circular shape of the opening in a camera lens, which is the same effect but more difficult to explain (at least for me). | [
"Star trail photographs are possible because of the rotation of Earth about its axis. The apparent motion of the stars is recorded as mostly curved streaks on the film or detector. For observers in the Northern Hemisphere, aiming the camera northward creates an image with concentric circular arcs centered on the no... |
if the water cycle is a closed system, why does it matter that a pound of beef takes 1800 gallons of water to produce? | It's a matter of clean/potable water. The water used to produce beef must be potable, and ends up non-potable, so that puts an enormous strain on the availability of clean water in an area. Yes, it does go back into the water cycle, but it takes a long while for it to make its way back to a drinkable state. | [
"Livestock and meat production have one of the largest water footprints of the agricultural industry. Taking nearly 1,800 gallons of water to produce one pound of beef and 576 gallons for pork. For reference, it only takes about 108 gallons of water to harvest one pound of corn. Livestock production is also one of ... |
why do you have to turn most jeans and some other clothing inside-out when washing them...? | You're supposed to turn clothes inside out?? I always thought it was the opposite, since it's the outside getting dirty (except for maybe underwear). | [
"t is often a requirement of \"home made\" garments (adhesive based transfers) that they be washed inside out, only in cold water, sometimes by hand, and not be tumble dried. The heat from washing or drying conventionally, or from ironing over the transfer area, can damage the transfer or cause it to separate. Thes... |
Mitochondria living outside of cells? | > are there still independent mitochondria somewhere on Earth
Not literally, because mitochondrial DNA is vestigial compared with their original ancestors. Mitochondria have only a few dozen genes, and have lost all the ones necessary for independent functioning.
So then, in the same spirit, are there independent descendants of the independent ancestors of mitochondria?
It would seem to be almost impossible to tell, due to both the dearth of mitochondrial DNA, to the fact that it mutates rapidly, and that it has been subjected to very heavy selection pressure for so very very long.
We would establish relatedness by an argument based on the similarity of mitochondrial DNA to some prokaryote's, but the above issues would appear to be more than sufficient to have made any similarities to be basically a matter of chance, even if they *were* related.
_URL_0_ | [
"Mitochondria are the \"power house\" of biological cells. It is thought that they were originally separate organisms, and a symbiotic relationship between them and early cellular life has evolved into their present position as cell organelles with no independent existence (see endosymbiotic theory).\n",
"Mitocho... |
Could dangerous radiation from depleted nuclear reactor cores be harvested? | For the broader question, we do: they're called [Radioisotope Thermoelectric Generators](_URL_0_). Basically, your intuition is correct: the heat produced by radioactive decay, when run through a thermocouple, generates electricity, making a sort of nuclear battery. Here's the thing: the strength of RTGs is that they can provide reliable power autonomously for long periods - that's why they're used for things like powering satellites, or remote automated facilities like modern lighthouses (the Russians were big on this design). These needed to be left alone for long periods while still being powered, but *they didn't require a lot of power* - RTGs generally only generate a few hundred watts or less, even for large ones.
So, for one, designing these things for broader use as power generation really isn't efficient, as their output is too low to be meaningful for civil use. Secondly, RTG fuels are carefully selected for their radioactive properties. Spent fuel from a fission reactor generally is too dangerously radioactive (and often toxic and corrosive to boot) to try monkeying around with them to build an RTG, especially when you're only talking about a few measly watts of power - it's simply not worth the cost, and is simply far safer and easier to go for reprocessing and safe storage. | [
"Since the radiation levels are still very high at the inside of the reactor core, it is not likely anyone can go inside to assess the damage. The Fukushima Daiichi Tracker (FDT) is proposed to see the extent of the damage from a safe distance. A few months of measurements with muon tomography, will show the distri... |
could someone please explain to me "bell's non-locality theorem"? | There is no way a five year old can understand the Bell Theorem; sorry.
I can still try to explain it, but not necessarily on ELI5 level.
In quantum mechanics, things are a bit different than in the macroscopic world.
For one, QM processes are not deterministic, but probabilistic. That means, that it is not possible to predict the outcome of an experiment; it is only possible to assign probabilities to different outcomes.
There are two different options why this is the case:
* There are so called local hidden variables that we have not yet discovered. Those variables determine the outcome, rendering QM deterministic again.
* QM is truly random. There are no variables that govern the outcome.
It turns out that we can actually test whether those local hidden variables exist.
This test is Bells Inequality. If it is violated, there are no local hidden variables.
Our testing has indeed suggested, that the inequality is being violated, thus QM is truly random.
I suggest you watch [this](_URL_1_) video from MinutePhysics for further explanation of determinism and probabilism; and [this](_URL_0_) video from Veritasim on the actual Bell Theorem. Both of these videos do a really good job explaining the phenomena. | [
"In mathematics, circle-valued Morse theory studies the topology of a smooth manifold by analyzing the critical points of smooth maps from the manifold to the circle, in the framework of Morse homology. It is an important special case of Sergei Novikov's Morse theory of closed one-forms.\n",
"The problem that Mor... |
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