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question stringlengths 3 301	answer stringlengths 9 26.1k	context list
why does water sometimes look so clear sometimes and so dark at other times?	A big part of it is the amount of life and dirt that's suspended in the water. Polar ocean waters are colder and more fertile (surprisingly) and as a result typically have a lot less clear water than warm ocean waters at the equator. Another part is that the water reflects the sky's brightness and partially transmits...	[ "Often it is the colour of freshwater or how clear or hazy the water is that is the most obvious visual characteristic. Unfortunately neither colour nor turbidity are strong indicators of the overall chemical composition of water. However both colour and turbidity reduce the amount of light penetrating the water an...
Did Mahatma Gandhi actually sleep with underage girls?	I have written about this [here.](_URL_0_) Short answer, not really true and blown of proportion, although there is room for criticism.	[ "Accounts by 19th-century historians suggest that Day grew impatient with the girls when they became bored with their lessons and began to squabble, and that he also spent significant time nursing them through a bout of smallpox. These accounts may have been exaggerated as both girls had been inoculated against sma...
If I were to make a baby, would it make a difference if I had sex while I was fit, or out of shape? Would that have an affect on what genetic traits I pass on to my child?	Technically, no. That's not how genetics works. Your lifestyle does not effect your genes. However, your lifestyle does effect which genes are active upon transmission, which effects how the embryo develops and will push into the future baby. So yeah, it might effect the genes of the baby somewhat. This is called epig...	[ "Choosing the sex of children might help prevent sex-associated heritable diseases such as Duchene muscular dystrophy or haemophilia in families with a history of these diseases. On the other hand, sperm sorting in humans raises the ethical concerns implicit to the idea of sex selection. If applied large-scale, it ...
How do western historians go about untangling the Falun Gong	This is old enough to not violate the 20 year rule, kinda, but I'll keep this short because it's a problematic question for AskHistorians for other reasons. FG is based off Qigong which became popular after the communists took power. FG itself didn't really get started until the 1990s. They weren't really on the radar...	[ "Following a period of meteoric growth of Falun Gong in the 1990s, the Communist Party launched a campaign to \"eradicate\" Falun Gong on 20 July 1999. The suppression is characterised by multifaceted propaganda campaign, a program of enforced ideological conversion and re-education, and a variety of extralegal coe...
Evolutionarily speaking, why/how did human sex and reproduction end up the way it is?	One characteristic of human sexuality that stands out in the primate world is the fact that [human females do not display any obvious outward signs of their estrous cycles](_URL_0_). In most other primate species, females display swelling and redness of the genitalia when ovulating. A quite reasonable explanation (prop...	[ "Modern explanations of the origins of human sexuality are based in evolutionary biology, and specifically the field of human behavioral ecology. Evolutionary biology shows that the human genotype, like that of all other organisms, is the result of those ancestors who reproduced with greater frequency than others. ...
Does the event horizon shred matter that passes through it?	> Does the event horizon shred matter that passes through it? The event horizon doesn't shred matter on its own, but matter will be shredded at some point usually near the event horizon due to tidal forces. For smaller black holes, the point of spaghettification is generally outside the event horizon. For larger ...	[ "Any object approaching the horizon from the observer's side appears to slow down and never quite pass through the horizon, with its image becoming more and more redshifted as time elapses. This means that the wavelength of the light emitted from the object is getting longer as the object moves away from the observ...
What was football like in 1300-1400s England?	I wrote about the history of football and the English attempts to ban the sport during the medieval period [in an earlier answer, here.](_URL_0_) Although not primarily focused on how the game was played (mainly because there were no generally agreed rules in this period, so it was played quite differently in differen...	[ "In 1314, Edward II, then the King of England, said about a sport of football and the use of footballs, \"certain tumults arising from great footballs in the fields of the public, from which many evils may arise.\" An account of an exclusively kicking \"football\" game from Nottinghamshire in the fifteenth century ...
How long does it take to test someone for coronavirus?	It depends on the test. The most common test for virus diagnostics is PCR, where you look for viral RNA in the patients sputum. This should produce a result in less than an hour, but the whole procedure would probably take several hours (including sample collection). Also, the hospital might need to "download" the COVI...	[ "The window period for a test is the amount of time from the initial infection event until the disease can be detected. Exposure to HIV, followed by replication of the virus, may take as long as six months to reach a level detectable in many testing methods. An HIV antibody test usually detects the HIV antibodies w...
Is it true that the Phoenicians might have discovered America before the Vikings and Christopher Columbus?	There are, in fact, many different theories purporting to "prove" a Phoenician presence in the Americas. Are we talking about Berry Fell claiming to have found "Punic" writing on a stone in Massachusetts? Possible Carthaginian coins in Alabama? Amphorae in a Brazil bay? Or maybe a rock in Brazil with purported Phoenici...	[ "The theory of Phoenician discovery of the Americas suggests that the earliest Old World contact with the Americas was not with Columbus or Norse settlers, but with the Phoenicians (or, alternatively, other Semitic peoples) in the first millennium BC.\n", "For a long time it was generally believed that Columbus a...
How would an aspiring conquistador acquire martial skills?	On the job training. Few if any would have had formal martial training. Some of the wealthier ones might have had some if they could have paid for it, but martial training was the preserve of the nobility and few conquistadors were noble. Those that came from the petty nobility (hidalguia) could have had some training ...	[ "Miguel Estete - Spanish military and conquistador (b. Santo Domingo de la Calzada, 1495 - d. Ayacucho about 1572), took part in the conquest of the Inca empire, participating in all major actions, including the capture of its last emperor, Atahualpa (1532). He saw the founding of San Miguel de Piura, chose the loc...
why is it that i cant remember what i did last week but i can remember the most random memories from years ago?	You've been doing the same thing everyday, so you're mind disregards situation which happen over and over. But, when you were a child you did almost everything for the first time so your mind decided to keep it. You probably remember your first day on the job but not your 20th. Same way with life	[ "The original 2011 study concluded with three main findings. First, people are primed to think of computers when asked general knowledge questions, even when they know the correct answer. In addition, this effect is especially pronounced if the question is difficult and the answer is unknown. Secondly, people do no...
In the run-up to WW1, was there a real possibility of the British Empire joining with the German Empire and it's allies, instead of the France/Russia?	There was no chance in 1914 that the UK would enter the war as an ally to Germany. The Asquith government was split on the question of whether to enter the war. But if they entered the war there was no question about what side they would support, and that was the French. And these opinions were shared across not just t...	[ "If the British Empire was now going to side with the Russian Empire, the Ottoman Empire had no choice but to cultivate a relationship with the Austro-Hungarian Empire, which was supported by the German Empire. In a few years these alignments became the Triple Entente and the Triple Alliance (already formed in 1882...
speed enforcement by photo and aircraft	A lot of places will use reference points for distance and time you, or just blow money on a radar. If you see large white markings on the side of that highway randomly, they're timing you to the next set.	[ "BULLET::::- Speed cameras that identify vehicles traveling over the legal speed limit. Many such devices use radar to detect a vehicle's speed or electromagnetic loops buried in each lane of the road.\n", "Cameras are associated with automated ticketing machines (known in the UK as speed cameras) where the radar...
what is the glycemic index?	Talking out of my pancreas here but let's say pure refined sugar is 100 on the glycemic index while something like an apple is 20. The apple has fiber that slows the digestion of the carbohydrates (glucose) . That slow down from the fiber let's your body use the glucose without spiking your blood sugar levels. Oh and s...	[ "The glycemic index is an indicator of the speed of resorption and conversion to blood glucose levels from ingested carbohydrates, measured as the area under the curve of blood glucose levels after consumption in comparison to glucose (glucose is defined as 100). The clinical importance of the glycemic index is con...
Is it possible for something to reach quadruple point? (Solid, liquid, gas, and plasma)	From the comment on [this thread](_URL_0_) answers it pretty well: > There is actually the Gibbs Phase rule which states that if you have a pure substance, then you can at most have a triple point. Quadruple or higher points are not allowed. Now if you have a two component system (water and ethanol or water and salt)...	[ "The liquid-liquid critical point theory can be applied to all liquids that possess the tetrahedral symmetry. The study of liquid-liquid critical points is an active research area with hundreds of papers having been published, though only a few of these investigations have been experimental since most modern probin...
Were infantrymen smaller and less muscular in WWII than they are now? If so, why?	During World War II, the average body measurements of the over six million male inductees into the U.S. Army was found to be 5 feet, 8 inches tall and 144 pounds in weight, on average an inch taller and eight pounds heavier than his Great War counterparts. He had a 33-1/4" chest measurement and a 31" waist measurement....	[ "These figures are very low for a battalion that was involved in so much combat, though it must be remembered that the Commandos were both smaller than the companies of the average strength infantry battalion of modern warfare and fighting with modern weapons and tactics against a relatively untrained, though well ...
what stops companies such as apple or abercrombie suing people in places, such as in turkey or india, who are selling fake merchandise or claiming to represent them?	The fact that its India and turkey. Laws and courts are different in different countries. Just because your company has a registered trademark in US doesn't mean anything in India.	[ "Countries have used smear campaigns to attempt to discredit Western companies. In 2011, China launched a smear campaign against Apple, including TV and radio advertisements and articles in state-run papers. The campaign failed to turn the Chinese public against the company and its products.\n", "On October 16, 2...
What would happen if the atmosphere was 78% oxygen and 21% nitrogen?	The risk of fires would increase a great deal, and this would reduce the amount of oxygen and increase CO2 considerably. This would likely lead to an increased greenhouse effect and greater plant growth. In the long term oxygen concentrations of that degree are unsustainable, and would naturally decrease. High oxygen ...	[ "Atmospheric nitrogen has a partial pressure of approximately 0.78 bar at sea level. Air in the alveoli of the lungs is diluted by saturated water vapour (HO) and carbon dioxide (CO), a metabolic product given off by the blood, and contains less oxygen (O) than atmospheric air as some of it is taken up by the blood...
What have been the deciding factors in selecting a location for new capital cities throughout various eras?	In Australia, the decision about where to put the capital city was purely political. During the negotiations leading up to federation of the Australian colonies, Sydney in the colony of New South Wales was the oldest and most prestigious city, but Melbourne in the colony of Victoria was the richest and most populous c...	[ "A 2004 study conducted for the Commission, known as the \"Palmer report\", demonstrated that the choice of European Capital of Culture served as a catalyst for the cultural development and the transformation of the city. Consequently, the beneficial socio-economic development and impact for the chosen city are now...
How did human species protect themshelves before the ability to make tools?	Since toolmaking by hominids far predates written history, this question is better asked in r/askanthropology	[ "Tool use has been reported many times in both wild and captive primates, particularly the great apes. The use of tools by primates is varied and includes hunting (mammals, invertebrates, fish), collecting honey, processing food (nuts, fruits, vegetables and seeds), collecting water, weapons and shelter. Research i...
Why do we use supergerm-creating Triclosan in anti-bacterial soaps instead of environmentally-friendly Tetrasodium EDTA	I can't answer your tetrasodium EDTA question. But I can tell you that Triclosan doesn't create "supergerms". Triclosan isn't that strong to begin with AND most pathogens have been resistant to it for quite some time. In the realm of antimicrobials, it's kind of a joke because of how little it really does for us.	[ "Triclosan (sometimes abbreviated as TCS) is an antibacterial and antifungal agent present in some consumer products, including toothpaste, soaps, detergents, toys, and surgical cleaning treatments. It is similar in its uses and mechanism of action to triclocarban. Its efficacy as an antimicrobial agent, the risk o...
Does the human brain really 'harden' at the end of puberty?	In addition - I'd like to ask a very similar question - what happens to the brain development of those who are castrated before puberty?	[ "The onset of puberty is associated with high GnRH pulsing, which precedes the rise in sex hormones, LH and FSH. Exogenous GnRH pulses cause the onset of puberty. Brain tumors which increase GnRH output may also lead to premature puberty.\n", "Puberty occurs through a long process and begins with a surge in hormo...
why is putin so threatened by nato? are his concerns justified?	Well, NATO is the most powerful military alliance in world history, and it is in the process of surrounding Russia. From a military standpoint, Russia is a shell of its Cold War glory days. In a conventional fight, the Russian Federation would be crushed. All it really has going for it is the nuclear stockpile. This me...	[ "Fallon referred to Russia under President Putin as a reason why NATO should be strengthened. It was Russia, whose cyberattacks and propaganda war was making the world less secure, Fallon continued. \"It is Putin, not Trump, who is aggressive. It is Putin and not Trump, who sets up new medium-range missile.\" Frenc...
why don't we use superglue to mend wounds anymore?	I'm an anesthesiologist, and the surgeons I work with use it all the time. It's not the right closure for some cases. In particular, it's only good for closing skin, not the underlying tissue (so it's useless as a solo item if you have a big laceration). It doesn't stretch well, so you can't use it over joints. It doe...	[ "Collagen is a natural product and is thus used as a natural wound dressing and has properties that artificial wound dressings do not have. It is resistant against bacteria, which is of vital importance in a wound dressing. It helps to keep the wound sterile, because of its natural ability to fight infection. When ...
when you get a cut, how does the body know how to heal it back to the same way it was before and not just grow out of shape.	Your DNA is the blueprint for your body, it's what tells your skin to be skin and what direction to grow in. The same thing happens when you get a scar as what happens as your body develops as a fetus, which is why scar tissue starts off as a light pink. Your DNA gives the same instructions as before but in this case a...	[ "Scar revision is a process of cutting the scar tissue out. After the excision, the new wound is usually closed up to heal by primary intention, instead of secondary intention. Deeper cuts need a multilayered closure to heal optimally, otherwise depressed or dented scars can result.\n", "When a normal wound heals...
Learning about Ancient Israel and Early Judaism	The book I think you want is Hershel Shanks's Ancient Israel. It's an edited volume, with an expert writing a chapter on each period but covering all the history in a single volume. Very good on archaeology. This is what all the graduate students (both those studying History of Judaism and the MDivs studying for main...	[ "In late antiquity, the two hubs of rabbinic learning were Babylonia and the land of Israel. Throughout the Amoraic period, many Babylonian Jews immigrated to the land of Israel and left their mark on life there, as rabbis and leaders.\n", "The oldest of the Indian Jewish communities was in the erstwhile Cochin K...
How did Ataturk afford his reforms?	It might be useful to separate the reforms under Atatürk as social and economic reforms. Social reforms include the abolishment of the sultanate in 1922 and of the Caliphate in 1924, the proclamation of the Republic in 1923, the introduction of a law coalescing all education under secular state authority in 1924, the a...	[ "Atatürk's Reforms () were a series of political, legal, religious, cultural, social, and economic policy changes that were designed to convert the new Republic of Turkey into a secular, modern nation-state and implemented under the leadership of Mustafa Kemal Atatürk in accordance with the Kemalist ideology. Centr...
If 99.9999999% of the matter/antimatter annihilated within 10s after the Big Bang, what happened to all that energy (radiation)?	> the annihilation reaction converts mass energy into radiation energy in the form of photons An [electron/positron annihilation reaction](_URL_1_) does produce only photons, but a [proton/antiproton reaction](_URL_0_) produces photons and mesons. > Wikipedia: When a proton encounters its antiparticle (and more ...	[ "On 14 May 2010, physicists at the Fermi National Accelerator Laboratory reported that the oscillations decayed into matter 1% more often than into antimatter, which may help explain the abundance of matter over antimatter in the observed Universe. However, more recent results at LHCb with larger data samples have ...
Whats the difference between high blood pressure and high heart rate?	High blood pressure refers to the pressure within your arteries. Specifically the numbers are "pressure when heart beats/pressure when heart rests" or systolic pressure/diastolic pressure. Higher blood pressure hints at narrowing arteries, or other illnesses where your heart has to work harder to pump blood around yo...	[ "During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure. The blood pressure in the circulation is principally due to the pumping action of the heart. Differences in mean blood pressure drive the flow of blood around the circulation. The rate of mean blood flow d...
What would daily life for people like Socrates and Plato have been like during the Peloponnesian War?	The duration of the Peloponnesian War was a hard time to be an Athenian. From the outset, Spartan raids on the Athenian countryside forced people to crowd into the city, where squalid conditions soon led to a catastrophic plague epidemic. Largely deprived of the produce from their own farms, Athenians relied for their ...	[ "For a time, Socrates fulfilled the role of hoplite, participating in the Peloponnesian War—a conflict which stretched intermittently over a period spanning 431 to 404 BC. Several of Plato's dialogues refer to Socrates's military service.\n", "Just before his death, Pericles' friends were concentrated around his ...
measurements of time, how did we get to define a day as 24 hours?	It's a convention that (mostly) started from the Egyptians. They divided the day in two part (day and night). One problem they had was to figure out the time during the night (you can't check the sun). Their astronomers noticed that by watching the stars they could divide the night into 12 part.	[ "In the modern metric system, hours are an accepted unit of time defined as 3,600 atomic seconds. However, on rare occasions an hour may incorporate a positive or negative leap second, making it last 3,599 or 3,601 seconds, in order to keep it within 0.9 seconds of UT1, which is based on measurements of the mean so...
In Band of Brothers, Donald Malarkey asks a German POW where he is from. He is surprised to hear Eugene, Oregon and the POW explains his family "answered the call" for all true Aryans to return to Germany. How common was it for German/Austrian-Americans to leave the USA and return to Germany?	Here is a great response from a similar question a few years ago by u/coinsinmyrocket _URL_0_	[ "When sailing from New York on August 21, 1919, Muck told reporters: \"I am not a German, although they said I was. I considered myself an American.\" He said he had \"bitter feelings\" toward the newspapers for their unfair treatment of him. He expressed doubts that the BSO, then in a sorry state of organization, ...
What evidence (if any) exists of cultural exchange between Ancient Rome and Southern India?	It's difficult to tease out many precise details in Indian history because the quality of the written records is not spectacular. The most solid evidence of cultural exchange of which I am aware is the arrival of Christianity in Kerala in the 1st C. CE (according to Church history, an apostle arrived as early as 52 CE)...	[ "Relations between India and Italy date back to ancient times. Works from authors such as Diodorus Siculus' \"Library of History\", Arrian’s \"Indika\", and Pliny the Elder’s \"Natural History\" make references to India. Trade links flourished between India and the Roman Empire, particularly in the first and second...
how/why do we get attached to people in a short time period?	For most of human history we did not have the luxury of taking your time for anything. Patience was not a virtue when you had only a few hours of daylight to get all the things needed to survive done. This includes making relationships. The individual may die at any time, but you may need their help, so it's beneficia...	[ "The intimacy between the people involved usually stems from a friendship with confidence to tell each other intimate aspects of themselves, their relationships, or even subjects they wouldn't talk with their partners. While not physical, this relationship can quickly pass that barrier, and while the first physical...
how were audio cassettes and vhs tapes mass produced? did the audio/sound have to be recorded in real time?	No, you can record faster than the playback speed. Many consumer dual cassette decks actually had this feature, called high speed copying or dubbing. You can also record many target cassettes from one source, so you'd have one master recording to many slaves.	[ "For the first several decades of disc record manufacturing, sound was recorded directly on to the master disc (also called the matrix, sometimes just the master) at the recording studio. From about 1950 on (earlier for some large record companies, later for some small ones) it became usual to have the performance ...
How were the European nations able to thrive after the Middle-Ages, as opposed to nations in other continents?	Well, first there's the fact that "the Middle Ages" is an ill-applied term in other continents. And in China, for example, the High Qing period of the 18th century is generally considered a golden age, an era when China reached unprecedented territorial extent and a period when great works of literature and art were ma...	[ "According to Wallerstein there have only been three periods in which a core nation dominated in the modern world-system, with each lasting less than one hundred years. In the initial centuries of the rise of Europe, Northwestern Europe constituted the core, Mediterranean Europe the semiperiphery, and Eastern Europ...
why does earth have a magnetic field and what would happen if it just randomly dissapeared?	Someone answered the first part so I'll answer the second since this was basically my bachelors dissertation topic: Charged particles can be moved by magnetic fields, and since the earth's field is quite strong and surrounds the planet, it acts as a sort of force field that protects the planet from the many charged pa...	[ "Earth's magnetic field, also known as the geomagnetic field, is the magnetic field that extends from the Earth's interior out into space, where it interacts with the solar wind, a stream of charged particles emanating from the Sun. The magnetic field is generated by electric currents due to the motion of convectio...
why is it that sometimes some electric windmills are not spinning despite facing the same direction as windmills that are spinning?	It takes a fair bit of oompf to get them going. Some have starter motors, but if the wind is just a bit slower for that one than others, it may not kick in. Also, they can have brakes put on so they're not spinning during maintenance.	[ "In this example, the correlation (simultaneity) between windmill activity and wind velocity does not imply that wind is caused by windmills. It is rather the other way around, as suggested by the fact that wind doesn’t need windmills to exist, while windmills need wind to rotate. Wind can be observed in places whe...
The Supernova of AD 675? (x-post from /r/askscience)	This is almost certainly not a supernova, as supernovas take a long time to fade (on the order of weeks to months) and would certainly have been reported from other parts of the world too. However, there are other alternatives: eclipses, comets, and interesting conjunctions. I haven't turned up any evidence for partic...	[ "The supernova was at magnitude 16.4 at discovery, and quickly rose to a peak magnitude of around 15.3 (in visible light) just over a week after discovery. By mid-May, the supernova had faded to 17th magnitude.\n", "There appear to have been two distinct phases in the early evolution of this supernova. There was ...
How fluent were Reformation era monarchs in languages other than their own?	Henry VIII spoke English, French, Italian and knew Latin and some Spanish. It was the same with Francis I. Charles V Holy Roman Emperor spoke German, French, and Flemish, later adding an acceptable level of Spanish. I think that Elizabeth I spoke French, Flemish, Italian and Spanish. By the time William Grindal beca...	[ "At the Reformation, the translation of liturgy and Bible into vernacular languages provided new literary models. The \"Book of Common Prayer\" and the \"Authorized King James Version\" of the Bible have been hugely influential. The King James Bible, one of the biggest translation projects in the history of English...
why do dark colored paints make rooms look smaller in comparison to light colors?	The way I explain it to my clients is that literally everything about colour is dependent on lighting. Dark colours tend to absorb light which tricks your eyes into comprehending the space differently. Light colours will reflect the light around and seem brighter. If you want to use mainly darker colours just make sure...	[ "a significant visual effect, due to the principle of chiaroscuro; dark shades tend to recede and be smaller, whereas light shades advance and seem larger. For example, vertical stripes with a light color in the middle and dark colors on the sides have a slimming effect. Psychologically, bright colors tend to be as...
From what I understand, what is now part of Ethiopia had an ancient Hebrew-speaking population (the Kingdom of Semien) and now contains some of the oldest populations of both Christians and Muslims. Why was this region seemingly so hospitable for followers of Abrahamic religions?	Edit: this post was apparently too long to post as one, so I broke it in two and posted the second part as a reply to the first. I probably could edit it for size, but since I already spent the time writing it, hopefully I'll be forgiven for not revising it so extensively as to cut it in half. Archaeology PhD here wi...	[ "A 2012 study on Ethiopian Jews showed that while they are primarily related to the local populations, Ethiopian Jews have very distant genetic links to the Middle East from some 2,000 years ago, and are likely descended from a few Jewish founders. It was speculated that the community began when a few itinerant Jew...
in canadian politics, why does quebec have to most seats?	Quebec does not have the most seats. They have 78 seats in the House of Commons to Ontario's 121, and in the Senate both Ontario and Quebec have 24 seats.	[ "Like the Canadian federal government, Quebec uses a Westminster-style parliamentary government, in which members are elected to the National Assembly after general elections and from there the party with the most seats chooses a Premier of Quebec and Executive Council of Quebec. The premier acts as Quebec's head o...
If I flip a coin 1,000,000 times, what are the odds of it beings heads AND tails 500,000 times?	What's important to realize is that the probability of every sequence with the same "outcome" (total # of heads in a given # of trials) is the same. HHTT is as likely as HTHT or TTHH. So to compute the probability of landing 500,000 heads in 1,000,000 trials, you have to calculate the probability of obtaining 1 partic...	[ "The probability of getting 20 heads then 1 tail, and the probability of getting 20 heads then another head are both 1 in 2,097,152. When flipping a fair coin 21 times, the outcome is equally likely to be 21 heads as 20 heads and then 1 tail. These two outcomes are equally as likely as any of the other combinations...
What was a Mesoamerican merchant's life like?	From Everyday Life of the Aztecs by Warwick Bray: > The traveling merchants, or pochteca, formed a separate class within Mexican society and are not to be confused with the pedlars and petty traders who sold their wares in the market places of the Valley. The pochteca engaged in foreign trade. They were organi...	[ "Little is known of Maya merchants, although they are depicted on Maya ceramics in elaborate noble dress. From this, it is known that at least some traders were members of the elite. During the Contact period, it is known that Maya nobility took part in long distance trading expeditions. The majority of traders wer...
Are there any biographies out there on the life of Harald Hardrada?	I can't find any books that focus exclusively on Harald Sigurdsson (aka "Hardrada"), no, but there are a few sources that will get you started in the right direction. These are the English references Claus Krag includes in his (relatively short) bio of him in the ODNB. * E.A. Freeman, *The history of the Norman conque...	[ "Most of Harald's biography remains uncertain, since the extant accounts of his life in the sagas were set down in writing around three centuries after his lifetime. Indeed, although it is possible to write a detailed account of Harald as a character in medieval Icelandic sagas (as this entry does), it is even poss...
why do companies like nikon sell cameras that around 16 megpixels but phone companies like sony and nokia sell phones that have 20 to 40 megapixel cameras?	Resolution is only one aspect of what makes a picture good. And once you can't see the pixels any more, increasing the resolution doesn't help (for reference, the 4K "ultra-HD" TVs they're selling now are only 8 megapixel). The problem with having tons of pixels is that it means very little light hits any portion of t...	[ "In an inversion, some phone makers have introduced smartphones with cameras designed to resemble traditional digital cameras. Nokia released the 808 PureView and Lumia 1020 in 2012 and 2013; the two devices respectively run the Symbian and Windows Phone operating systems, and both include a 41-megapixel camera (al...
I recently heard that the word "Hello" was invited as a telephone greeting and didn't exist until the 1890s. How true is this?	Not quite, it seems. According to the OED: "hello" is a variant of "hallo" which is in use from ca. 1830. "Hallo" derives from German "hallo, halloh," also Old High German "halâ, holâ," imperative of "halôn, holôn" to fetch, used especially in hailing a ferryman. Also written "hullo(a, hillo(a, hello," from obscurity o...	[ "The use of \"hello\" as a telephone greeting has been credited to Thomas Edison; according to one source, he expressed his surprise with a misheard \"Hullo\". Alexander Graham Bell initially used \"Ahoy\" (as used on ships) as a telephone greeting. However, in 1877, Edison wrote to T. B. A. David, president of the...
When did we start writing science fiction?	Scifi is actually much older than you would think. I actually was just wondering about this question after reading some Voltaire. As early as the 17th century authors were writing the precursors of modern science fiction. [The Man in the Moone](_URL_1_) was published in 1638 and described travel to the moon. Voltai...	[ "Although science fiction had been published in the United States before the 1920s, it did not begin to coalesce into a separately marketed genre until the appearance in 1926 of \"Amazing Stories\", a pulp magazine published by Hugo Gernsback. By the end of the 1930s, the field was undergoing its first boom, but Wo...
eli: why do we need daylight saving time?	Easy: We don't. DST is a man-made idea to change the feel of the day. We work and play when the sun's up and sleep when it's dark, right? Think of this - You need to get up every day at 7AM to get ready for work or school. In the spring, daylight starts at 6:30 and goes until as late as 8PM in the summer. But when win...	[ "Many people believe that daylight savings time was first created for agricultural or inter-state commerce purposes, but it was really started by Germany and France during World War I in an effort to save coal by reducing energy consumption with a longer day. Today, the reality is that this reduction in energy cons...
why are we so ashamed of our genitals?	Blame the [Victorian era](_URL_0_) 1837-1901 for the spread of puritanical 'moral' sentiment around the globe (with the British empire). The echos are still with us today. Police able to demand a woman submit to a STD check? Yup. Rude to say 'leg' in formal company (say 'limb' instead)? Yup. They were prudish in ...	[ "Societal views, influenced by tradition, a lack of knowledge on anatomy, or sexism, can significantly impact a person's decision to alter their own or another person's genitalia. Women may want to alter their genitalia (vagina or vulva) because they believe that its appearance, such as the length of the labia mino...
why cardio is better than weight lifting at burning fat.	Actually, it's the other way around. You burn calories for the duration of cardiovascular exercise, but you stop burning calories when you discontinue the exercise. Conversely, with weight lifting, your heart rate will stay elevated for hours and hours afterwards, leading to more calories burned (in addition to gaini...	[ "The process of regaining weight and especially body fat is further promoted by the high metabolic plasticity of skeletal muscle. The \"Summermatter Cycle\" explains how skeletal muscle persistently reduces energy expenditure during dieting. In addition, food restriction increases physical activity which further su...
dating rules.	Dating is just like making a new friend. You go about it the same way you do with anyone. You start a conversation and if you enjoy each other's company then you make a plan to see each other again. You keep doing that until you decide you like that person so much that you only want to date them. At some point in...	[ "Dating systems can be systematic and organized ways to improve matchmaking by using rules or technology. The meeting can be in-person or \"live\" as well as separated by time or space such as by telephone or email or chat-based. The purpose of the meeting is for the two persons to decide whether to go on a date in...
why are ssd's really small?	There are standard sizes for drives and SSDs are made to fit them so they can be mounted in standard receptacles. You can get 3.5" drives which are pretty sizable.	[ "Consumer flash storage devices typically are advertised with usable sizes expressed as a small integer power of two (2, 4, 8, etc.) and a designation of megabytes (MB) or gigabytes (GB); e.g., 512 MB, 8 GB. This includes SSDs marketed as hard drive replacements, in accordance with traditional hard drives, which us...
what ignites a star... why does all of that hydrogen congregate in one area?	Gravity. Hydrogen is matter, and it has gravity. You do need some sort of disturbance to get stuff to start clumping, but once it does, each clump will keep on attracting more hydrogen until either there is no more in the area, or it ignites, creating a solar wind that pushes the hydrogen away. If hydrogen has mass a...	[ "When the Sun ignited in the solar nebula, hydrogen, helium and other volatile materials were evaporated in the region around it. The solar wind and radiation pressure forced these low-density materials away from the Sun. Rocks, and the elements comprising them, were stripped of their early atmospheres, but themsel...
Did the WW1 Russians consider using the Black Sea Fleet to bombard Istanbul as the British and French intended before Gallipoli?	Yes Constantinople did have several shore batteries of varying quality, but the presence of German 'Advisors" greatly increased their efficiency, as demonstrated down flow at Gallipoli and in the Dardanelles. The biggest threat to the Black Sea Fleet was far and away the Battlecruiser Goeben, a fully modern warship, ...	[ "The Ottoman press reported the action on 31 October, claiming that the Russians had planned on mining the Bosphorus and destroying their fleet without a formal declaration of war, compelling the Ottoman navy to retaliate after an engagement at sea by bombarding the Russian coast.\n", "The reaction in the Ottoman...
Astronomy: how did the universe go from a measurable size to infinite, aka not an actual number?	This is a good question, and the answer might not be entirely satisfying. I think it's best not to think of the size of the Universe as a whole. This is because, as you say, infinity isn't an actual number, and if we start talking about quantities like "the size of the Universe" which could well be infinite, we're goin...	[ "The poet Edgar Allan Poe suggested that the finite size of the observable universe resolves the apparent paradox. More specifically, because the universe is finitely old and the speed of light is finite, only finitely many stars can be observed from Earth (although the whole universe can be infinite in space). The...
Why do polarized lenses change colors when they are turned 90 degrees?	EDIT: I think I figured it out. My best understanding is just below. My original ideas are at the end of this post. RealD 3D displays work by circularly polarizing light. The image intended for your right eye is polarized in one direction (let's say right circularly polarized), and the image intended for your left...	[ "Circular polarization has an advantage over linear polarization, in that the viewer does not need to have their head upright and aligned with the screen for the polarization to work properly. With linear polarization, turning the glasses sideways causes the filters to go out of alignment with the screen filters ca...
i've heard that services like uber & lyft are in a legal "gray area", and they have been ruled legal in some places, but illegal in others. why is this?	It's new, legislation hasn't caught up yet. In 5-years, these guys will be paying extra for licenses, insurance, fines, health/safety and all sorts of other bureaucracy	[ "Many governments and taxi companies have protested against Uber, alleging that its use of unlicensed, crowd-sourced drivers was unsafe and illegal. Uber operates and functions as a taxi service company for the public by dispatching drivers to provide transportation services to passengers who pay Uber mileage-based...
If Mars's atmosphere is almost completely CO2, couldn't Earth's plants survive there?	The atmosphere is very thin, and doesn't block enough solar radiation.	[ "The Martian atmosphere contains high abundances of photochemically produced CO and H, which are reducing molecules. Mars' atmosphere is otherwise mostly oxidizing, leading to a source of untapped energy that life could exploit if it used a metabolism compatible with one or both of these reducing molecules. Because...
What was the first team sport that resembled modern leagues?	In the European context we trace it back to the Ludi Romani (Roman Games) held at the Circus Maximus (lit. big circuit) in Rome. The agitatores (Chariot drivers) competed together as teams during races, the first of these teams were apparently created during the Kingdom period sometime between the 8th c. and the 6th c....	[ "Professional sports leagues are organized in numerous ways. The two most significant types are one that developed in Europe, characterised by a tiered structure using promotion and relegation to determine participation in a hierarchy of leagues or divisions, and a North American originated model characterized by i...
The Yellow Turban Rebellion in China took 21 years to suppress. I can't think of any peasant rebellion in Europe that lasted that long. Am I wrong? What were the situations that allowed a peasant rebellion to last so long?	It is a bit misleading to say that the Yellow Turban Rebellion took 21 years to suppress. It started out as a religious movement and then became a widespread rebellion organised by its leader Zhang Jue in March 184. Though they had some initial successes, the tide started turning soon enough as the government started o...	[ "Although the Yellow Turban Rebellion ended by February 185, smaller rebellions by Yellow Turban remnants continued to break out throughout China over the following decades, even in provinces which were previously largely unaffected.\n", "The Red Turban Rebellion () was an uprising influenced by White Lotus membe...
Did the clan system also exist in the Scottish lowlands?	I can't give a reason as to why specifically different terminology has been employed, but I'm familiar with family organisation in the Borders due to my work on crime in the sixteenth century. You're right that the cultures diverged somewhat over time. From the twelfth century, increased Anglo-Norman influence brough...	[ "The combination of agnatic kinship and the feudal system, which formalised mutual obligations of service and protection, organised through heritable jurisdictions, has been seen as creating the Highland clan system. The head of a clan was usually the eldest son of the last chief of the most powerful sept or branch...
if taxes are taken out of each of my paychecks, how come i need to pay taxes again every april?	Because it's an estimation. If you look on a tax form 1040, there are a ton of other issues that will reduce or increase your liability. Did you get married? What is your filing status? Do you have itemized deduction (mortgage interest, medical expense). Did you get interest income, dividend, etc. Did your business ...	[ "BULLET::::- A contributor who would otherwise owe more than $3,000 in taxes at the end of the year ($1,800 in Quebec) can relieve themselves of the obligation to pay their taxes in instalments by reducing the net tax owing below the relevant threshold. By not having to pay instalments, such contributors effectivel...
What is something that I, as a pretty average Joe American, can do that would ease the jobs of future historians?	To document our time? Write a diary. Do the most good? Write a peer-reviewed book about something that isn't World War II and contains footnotes, a bibliography and index.	[ "A Chance to Make History: What Works and What Doesn't in Providing an Excellent Education for All () is a book by Wendy Kopp, CEO and Founder of Teach For America, that was published by PublicAffairs in January 2011.\n", "He has published the books \"The American Economy in Historical Perspective, Unemployment a...
why do some people resort to their "native tongue" when stressed or under the influence	My girlfriend starts speaking Spanish during sex. I have no idea what she's saying, she could honestly be saying some fucked up shit to me but it sounds hot as fuck lol	[ "Also, as a consequence of violence and oppression towards indigenous people, some natives and descendants choose to not identify themselves as indigenous, further reducing the number of people categorized as speaking the language (Facundes 23, 2000). The low transmission and cultivation of the language result in t...
What determines the axis of a black hole's accretion disk? Is its orientation always stable?	The accretion disc of any collapsing dust cloud emerges from the shape of the cloud and the initial velocities of the particles. As opposing momentums cancel and similar momentums combine, the cloud gradually develops a spin which reinforces itself by first accelerating the surrounding orbiting particles into having a ...	[ "An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is typically a star. Friction causes orbiting material in the disk to spiral inward towards the central body. Gravitational and frictional forces compress and r...
How much of the ocean floor sees sunlight?	According to the [National Oceanic and Atmospheric Administration](_URL_0_), light rarely travels any deeper than 200 meters, and never any further than 1,000m (under completely optimal conditions). I don't have the resources to find out how much of the ocean floor is less than 1,000 meters deep, but I can tell you tha...	[ "The sunlit zone of the ocean is called the photic zone (or euphotic zone). This is a relatively thin layer (10–100 m) near the ocean's surface where there is sufficient light for photosynthesis to occur. For practical purposes, the thickness of the photic zone is typically defined by the depth at which light reach...
Can each personality in people afflicted by Dissociative identity disorder really have different illnesses ?	[Myopia](_URL_0_) is a physical problem with the eyes. The lens focuses incoming light improperly so that the focal point is in front of the retina rather than being directly on it. A person with dissociative identity disorder may have personalities that like to wear glasses, but from a physical standpoint, there is no...	[ "People who suffer severe disturbances of their self-identity, memory and general awareness of themselves and their surroundings may be classed as having a dissociative identity disorder, such as depersonalization disorder or Dissociative Identity Disorder itself (which has also been called multiple personality dis...
Why do humans die at body temperatures of 42°C, while the same temperature is normal for birds?	As you suggested, protein denaturation is the reason why humans become very unwell and eventually die with a core temp of 42ºC. When it comes to protein stability and evolution, evolution typically does not select for stability, but rather function. So if being stable at 42ºC is required for function, evolution will s...	[ "The most significant cause of death in temperate areas is likely to be starvation, particularly over the autumn and winter period when first year birds are still perfecting their hunting skills. In northern and upland areas, there is some correlation between mortality in older birds and adverse weather, deep-lying...
why do other countries dislike america so much?	They don't, or at least no more than they think the French are all mimes in stripy sweaters with a baguette in one hand and ring of garlic around their neck or that Australians are all crocodile hunter types with a beer in one hand having a BBQ. Stereotypes are a long running way to characterise or pick fun of a count...	[ "America Against the World: How We Are Different and Why We Are Disliked is a non-fiction book that was written by Andrew Kohut and Bruce Stokes in 2007 about United States foreign policy and the causes of dislike of Americans in other countries. Kohut is a former president of the American Association for Public Op...
How does fluoride ion (HF acid) hydrolyze amides and esters, why is it so corrosive?	Shamefully you stumped me and I had to go look in Housecroft and Sharpe to figure it out! You probably know most of this, but to reiterate... The Pka value for HF, as you rightly say, is high(ish), suggesting low dissociation in aqueous solution. The reasons for this are two-fold: 1. The H-F bond is strong 2. The ent...	[ "Upon treatment with a standard acid, fluoride salts convert to hydrogen fluoride and metal salts. With strong acids, it can be doubly protonated to give . Oxidation of fluoride gives fluorine. Solutions of inorganic fluorides in water contain F and bifluoride . Few inorganic fluorides are soluble in water without ...
when characters in movies and tv shows get stabbed, how do they make the sword appear to realistically go through the actor?	The old school way is a prop sword, which collapses in on itself when pressure is applied to the tip just like a toy lightsaber. Then, they will cut away to another angle where the stabee has a sword chunk sticking out his back. This is attached to his skin through liquid latex and a bunch of fake blood. CG has ma...	[ "BULLET::::- In a sword fight, when a large number of villains attacks the main character, they never attack at once. The main character first launches into a lengthy preamble detailing the crimes the villains have committed, at the end of which the villains then initiate hostilities. The villains charge singly or ...
when you use headphones with built-in microphones with your phone, how does your phone know which microphone to use?	The phone has a sensor that can tell when something is plugged into the headphone jack. Then it puts a little tiny voltage on the wires in the jack and then measures the current that each wire draws. Headphones and mics all will draw a slightly different amount of current and so the phone can figure out that there's ...	[ "In pro-audio terminology, a headphone amplifier is a device that allows multiple headsets to be connected to one or more audio sources (typically balanced audio sources) at the same time to monitor sounds during a recording session, either singing or playing from the \"live room\" or recorded tracks. Headphone amp...
WWII Invasion of Hawaii	No, they would not have had the logistics capacity to sustain an invasion of Midway, let alone the main Hawaiian islands, which were not (and are not) remotely self-sustaining in food. I wrote about this before here: _URL_1_ and here _URL_0_ And also check out the answers from u/dbht14 in the first linked thread.	[ "Following the overthrow of the Hawaiian Kingdom, the United States Navy established a base on the island in 1899. On December 7, 1941, the base was attacked by the Imperial Japanese Navy airplanes and midget submarines, causing the American entry into World War II. One of the main reasons that Pearl Harbor happene...
What would happen to some degenerate neutron matter if you could remove it from a neutron stars gravitational field?	gravity would no longer maintain it, so it would rapidly expand. for starters you have normal gas pressure, a teaspoon of neutron star material would have the same mass of mountain, assuming it would expand to water density, it would swell to a 700m sided cube. Instantly. Big ass explosion. Alas, that would be noth...	[ "Current theories of neutron star structure and evolution predict that pulsars would break apart if they spun at a rate of c. 1500 rotations per second or more, and that at a rate of above about 1000 rotations per second they would lose energy by gravitational radiation faster than the accretion process would speed...
Why do we get happy when we see other people who are happy?	It's because of our mirror-neurons that emulate feelings of others and play a big role in Empathy. _URL_0_	[ "\"...[A]pparently a happy man only feels so because the unhappy bear their burden in silence, but for which happiness would be impossible. It is a general hypnosis. Every happy man should have some one with a little hammer at his door to knock and remind him that there are unhappy people, and that, however happy h...
Why is Liechtenstein?	I love Liechtenstein! The short answer is three parts: a late start, good alliances, not being a belligerent. A Late Start First of all, you wouldn't consider Liechtenstein to be a "country" or even an "independent principality" by contemporary European standards until 1719. Before that, the area was...	[ "Liechtenstein ( ; ), officially the Principality of Liechtenstein (), is a doubly landlocked German-speaking microstate in Alpine Central Europe. The principality is a constitutional monarchy headed by the Prince of Liechtenstein.\n", "Liechtenstein is a small, landlocked country located in the Alpine region of ...
why is it more favorable to breed a dog so that it ends up having multiple health problems later in life?	It is not more favourable to breed a dog so it ends up having issues later on in life. What you are referring to (using Bulldogs specifically) is the breed standard which has changed over the years. If you were to take that same breeds standard going back several years, you'll read some marked differences. While some ...	[ "As some health problems are hereditary, knowing the common health problems that are related to the type of dog you are trying to breed can be used to improve its successors by mating the dam with a sire who has a pedigree that lacks these health issues. By studying a dog’s pedigree, you can avoid breeding dogs kno...
why do inhalers let you breathe instantly during an asthmatic attack?	An asthma attack happens when parts of the lungs squeeze shut, generally in response to a perceived threat. This stops air from reaching the lungs. Normally, your brain sends a signal to these parts of the lungs telling them to open again shortly afterwards, but for one reason or another this doesn't happen for someon...	[ "Dealing with asthma attacks is an important factor of Buteyko practice. The first feeling of an asthma attack is unsettling and can result in a short period of rapid breathing. By controlling this initial over-breathing phase, asthmatics can prevent a \"vicious circle of over-breathing\" from developing and spiral...
if a dark-skinned population moved to an area currently populated by fair-skinned people (eg scandinavia) and didn't interbreed, would they eventually become white-skinned? if so, how long would it take? and would the same be true for a fair-skinned people moving to, say, central africa?	TL;DR - Probably not, because modern food, clothing, and shelter cancel out most of the survival benefits for light/dark skin in different regions. The first part (black people becoming white) would probably not happen under modern conditions. The major evolutionary advantage of being white is that it allows you to ...	[ "White northern Europeans appear to be affected more frequently than other races, though a paucity of reliable epidemiology exists in the Southern Hemisphere. Children of sufferers of the disease themselves may have a very slightly increased risk, though it is unclear if this is because of a genetic predisposition,...
in the us, your phone number is 10 digits. that means 9,999,999,999 (ten billion) possibilities. how is there not more (existing and previously existing) phone numbers than that?	That's a good question. * First digit(s) is/are the country code. The US is 1, and you don't need to include it if you live in the US. * Digits #2, 3, 4 are the area code. This is assigned to a specific region. * Digits #5, 6, 7 are a more specific grouping code, usually referring to a geographic area, telephone exch...	[ "In the United States and Canada, ten-digit dialing is the practice of including the area code of a telephone number when dialing to initiate a telephone call. When necessary, a ten-digit number may be prefixed with the trunk code \"1\", which is often referred to as \"11-digit dialing\" or \"national format\".\n",...
what causes those cringe like chills you get when certain fabrics or textures are rubbed together?	Brushed metal. When my Macbook touches my phone, or a certain part of the charger, or if I mess up when trying to put a USB in and it touches the body of the computer, ugh chills.	[ "This reddened skin or rash may signal a deeper, more serious infection of the inner layers of skin. Once below the skin, the bacteria can spread rapidly, entering the lymph nodes and the bloodstream and spreading throughout the body. This can result in influenza-like symptoms with a high temperature and sweating o...
Do other animals breathe out of both their mouth and noses or is it unique to just some?	The evolution of nasal passages is actually quite interesting. Fish typically have [four nostrils arranged in two pairs](_URL_3_), which are used for detecting chemicals but cannot be used to breathe since they just lead to a dead end. Despite appearances, humans and other tetrapods actually also sort of have four no...	[ "A nostril (or naris , plural \"nares\" ) is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation. Fish do not...
how come when i go to the junkyard and see completely totaled vehicles, i never see blood stains?	Usually, the vehicles have been smashed up moving them around, or on purpose to take up less space. Also, most car crashes don't end up in blood, and very rarely a lot of blood. The most common reason that a car would be scrapped after a crash is simply part of the structure of the car breaking in such a way that it wo...	[ "By the time the police impounded the truck allegedly used, there were signs that it already had been washed, but despite this, police found blood and other physical evidence on the undercarriage of the truck and the blood was identified as belonging to McClelland. The police affidavit for Finley's arrest alleged t...
Is Kiev really that relevant to Ukraine?	Without getting too much into the details, this is a dangerous line of questioning to get into. The borders of Eastern Europe shifted constantly until the 1950s. Many countries (including Ukraine) ceased to exist during many periods of time, and there were multiple times when countries (including Ukraine) existed but w...	[ "Russia and Ukraine share much of their history. Kiev, the modern capital of Ukraine, is often referred to as the \"mother of Russian cities\" or a cradle of the Rus' civilisation owing to the once powerful Kievan Rus' state, a predecessor of both Russian and Ukrainian nations.\n", "Kiev is the undisputed center ...
Why is the UV index so much higher near the equator than in higher latitudes during the summer?	At the equator the suns rays are reaching you straight on through the atmosphere. At a higher latitude, they come through at an angle relative where you are standing. The effect of this is that they travel through more of the atmosphere, and thus more of the damaging UV light is scattered/absorbed.	[ "The UV Index is a linear scale, with higher values representing a greater risk of sunburn (which is correlated with other health risks) due to UV exposure. An index of 0 corresponds to zero UV radiation, as is essentially the case at night. An index of 10 corresponds roughly to midday summer sunlight with a clear ...
why does your car horn sound differently when you lock it and when you press down on the steering wheel?	Car horns are usually made of two horns that are two notes designed to be slightly off. This makes the car horn very noticeable. When you hit your remote to lock the car, your car only plays one of the two horns, since it is only supposed to be a confirmation to you, not a signal to everyone.	[ "One problem with this system is that once the spring or the top plate becomes worn, the driver of a car with this system may hear a loud \"clonk\" noise at full lock (i.e. steering wheel turned to the extreme left or extreme right positions), as the strut's spring jumps back into place. This noise is often confuse...
What is this? Neither Space or Geology could tell what it is. Maybe you can?	Looks to me like a lot of broken glass cast in some resin. Perhaps part of an old sculpture or other piece of art, abandoned years ago?	[ "Reacting to a photo published by Swedish newspaper Expressen purportedly taken by Ocean X during a dive to collect rock samples, Göran Ekberg, marine archaeologist at Sjöhistoriska museet (Maritime museum) in Stockholm said, \"A natural, geological formation can't be ruled out. I agree the finding looks weird sinc...
Why would non-resistant bacteria out-compete resistant strains in the absence of selective pressure of an antibiotic?	Gene expression isn't free; every protein a cell generates takes energy away from other things (such as reproduction). If resistance in MRSA functions by expressing an additional gene (or more) to produce additional proteins (compared non-resistant SA), the MRSA is expending slightly less of its energy on reproduction...	[ "However, due to selective pressure, bacteria can develop resistance through mutations in the porin gene. The mutations may lead to a loss of porins, resulting in the antibiotics having a lower permeability or being completely excluded from transport. These changes have contributed to the global emergence of antibi...
Given the rate at which tectonic plates are created and destroyed, how is it possible that some parts of plates are billions of years old?	Short answer, because of density contrasts. Tectonic plates are composed of two types of crust, oceanic and continental, which differ in their bulk compositions and thus their densities. Continental crust is generally much less dense than oceanic crust. In detail, continental crust is so buoyant compared to either ocea...	[ "In the history of Earth many tectonic plates have come into existence and have over the intervening years either accreted onto other plates to form larger plates, rifted into smaller plates, or have been crushed by or subducted under other plates (or have done all three).\n", "Conventional plate tectonics accoun...
What is the truth about Martin Luther King Jr.?	We don't know, as King made no public statements re: Jews or Zionism. The "Letter to an anti Zionist friend" attributed to King has been exposed as a hoax. The notion that King met Hitler is simply idiotic. King never traveled to Germany as a child, Hitler never came to the US, and hitler hated blacks. Many in the ...	[ "In 1997, 29 years after Martin Luther King Jr.'s death, Dexter met with James Earl Ray, the man imprisoned for his father's 1968 murder. When confronting him, King asked Ray, \"I just want to ask you, for the record, um, did you kill my father?\" Ray replied, \"No-no I didn't.\" King then told Ray that he along wi...
isn't rape very painful to a man as well without lubrication? how can rapes happen when even consensual sex with not enough lubrication feels very painful to a man as well?	Spit and a woman's natural lubrication. A women will create lubrication during a rape or forced sex in a lot of cases. When genitals are in direct contact with friction and motion there is only so much control that can be had for either gender. Having their bodies comply is part of the shame that is experienced afterwa...	[ "BULLET::::- That it is not rape unless the victim fights/physically resists, or that it is not rape unless the victim is physically coerced or injured. (In reality, many rapes do not involve physical coercion, as in cases where the victim is impaired/unconscious, or where an unequal power relationship forces the v...
Are there exercises that can improve the mind?	Meditation. Pick your study from _URL_0_ 15 minutes is perfect for a quick session. r/meditation has good intro resources to get you going.	[ "Suzuki's research in 2018 focused on the impact of exercise on the brain. Her group is working to develop a \"prescription\" for the right amount of exercise to maximize brain activity for a range of purposes including; learning, aging, memory, attention, and mood. To support that work, the Suzuki lab is researchi...
How did Biblical hymns eventually gain their melody?	It depends on the hymn, but some of the melodies for hymns are very old indeed, dating from late antiquity or the early Middle Ages. These oldest tunes were the standard accompaniments to the Roman Catholic liturgy. Psalmodies, the tunes to which the psalms are sung between the liturgical readings, are some of the ol...	[ "In the medieval era, early Christian hymns featured organum (which used the simultaneous perfect intervals of a fourth, a fifth, and an octave), with chord progressions and harmony an incidental result of the emphasis on melodic lines during the medieval and then Renaissance (15th to 17th centuries).\n", "In the...
Dear Science, is it possible for a magnet to be so strong it damages living cells/tissue?	if you were near a Magnetar, it would be able to rip the water in your body out.. destroying your tissues. _URL_0_	[ "The greater force exerted by rare-earth magnets creates hazards that are not seen with other types of magnet. Magnets larger than a few centimeters are strong enough to cause injuries to body parts pinched between two magnets or a magnet and a metal surface, even causing broken bones. Magnets allowed to get too ne...
why does the gop typically have more candidates in the primaries?	The republican party is doing some serious soul-searching right now, and the different candidates generally represent the various interest groups that collectively make up the republican party. They are, in no particular order: * The establishment (Rubio) * The anti-establishment (Trump) * The far-right/evangelicals (...	[ "BULLET::::- There was also speculation that the 2008 Republican primaries would result in a brokered convention, due to the number of strong candidates and their different geographic bases. The number of \"winner take all\" states benefits candidates with strong regional support. In addition, the weakened power of...
what is meant by a 'state of maximum entropy'?	If you have a bathtub full of hot water in a cold room, the entropy is quite low because the energy is concentrated in the water. Over time, the bathwater cools and the air in the room heats up, as energy flows from the water, until the air and the water are the same temperature. As energy is distributed evenly, entrop...	[ "Though the maximum entropy approach is based directly on informational entropy, it is applicable to physics only when there is a clear physical definition of entropy. There is no clear unique general physical definition of entropy for non-equilibrium systems, which are general physical systems considered during a ...
Why can't we fry stuff in substances like water, as opposed to frying them in oil?	I gave this answer to a similar question: One reason for using oil is just to make a thermal path between the pan and the food, so the food doesn't only cook exactly where it touches. Water could also do this, though it would evaporate quickly. The reason boiling water can't brown the food, is that water cannot be ...	[ "There are many cooking techniques that do not use oil as part of the process such as steaming or boiling. Water based techniques are typically used to cook vegetables or other plants which can be consumed as food. When no oil is present the method of heat transfer to the food is typically water vapor. Water vapor ...
is integral calculus, specifically used in programming, computer science? and how?	The answer of course is "it depends". It depends completely on what it is you're programming. If you're writing an operating system, I can't think of any situation where you'll be using Newton's/Liebniz's calculus. If you're writing either the front- or back-end of a database-powered application, it's highly unlikely....	[ "In mathematics, non-standard calculus is the modern application of infinitesimals, in the sense of non-standard analysis, to differential and integral calculus. It provides a rigorous justification for some arguments in calculus that were previously considered merely heuristic.\n", "\"Integral calculus\" is the ...

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