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What did other periods in the history of the British isles think of stone henge?

Some parts of your question were covered in [this earlier answer,](_URL_1_) which points out that the earliest certain written record of Stonehenge only dates from the late Norman period (c.1130). And even after that, it wasn't until the first stirrings of antiquarianism in the mid-17th century that we get any sort of significant flow of information about the site and how it was regarded. All that said, we do have some clues. Let's review the ways things stood from period to period. **Saxon era** The word "Stonehenge" is a corruption of the Saxon *Stanenges*, "hanging stones". It's usually supposed the name was given to the site because the trilithons at its centre reminded people of gallows. Some support for that supposition comes from the discovery of the victim of a Saxon-era execution (an articulated skeleton known to archaeologists as "burial 4.10.4"), whose remains were found in 1922, inhumed in the north-east ditch that surrounds the monument. These remains were long thought lost, but when rediscovered in 1999 they were carbon-dated to c.600-690. The victim, a male of 5 feet 4 inches (1.65m), who may have been either Saxon or a Briton, and was aged 28-32, had been decapitated with a single well-aimed blow from an axe or sword. Pitts et al observe that several known Saxon execution sites are associated with Neolithic monuments such as long barrows. Hence we have some evidence that for the early Saxons, Stonehenge may have been an execution and funerary site. Also worth noting, Pitts says, is that this burial is "the oldest indication we have that Stonehenge had a significance in recent centuries." **Norman period** The chronicler Henry of Huntingdon wrote about Stonehenge in the context of his listing of the four great wonders of England. For his (much less reliable) contemporary Geoffrey of Monmouth, who claimed to base his work on a probably non-existent old Welsh book, Stonehenge was a memorial to British soldiers killed by Saxon invaders led by Hengist in the fifth century AD, and later the burial site of two great British kings, Aurelius Ambrosius and Uther. **From 1130-1530** Stonehenge again goes largely unrecorded in this period. The historian and Tudor propagandist Polydore Vergil mentions it, but only to repeat Monmouth's account. **Mid to late Tudor period** The first known image of Stonehenge was executed probably by Joris Hoefnagel in 1568 or 1569. The original is lost, but [several versions of it exist,](_URL_0_) including a print by "R.F." and a watercolour by Lucas de Heere. It's notable for its inaccuracy, showing the stones as "curvaceous as a Modigliani nude" (Burl) and focussing, as do so many later descriptions, on the sarsens rather than the less well preserved bluestone circle. The topographer William Camden mentions the site in his *Britannia* (1588), though without devoting the sort of attention we might expect from our more modern perspective. He focused on the monuments; physicality, calling it "a huge and monstrous piece of work," made of "certain mighty and unwrought stones." He added that some thought the stones themselves were artificial, not things that had been quarried and carved, being stuck together with "some glewie and unctuous matter". **Stuart period** The first systematic investigations of Stonehenge date to this period. James I and other members of a party paying a visit to the Earl of Pembroke, who lived nearby, excavated some ox bones from the site in 1620 (which they speculated were the products of sacrifices once made there), and the king asked his architect Inigo Jones to investigate the monument's history. Jones pitched a tent at the henge and took measurements, also excavating to find out how deeply embedded the stones were in the local chalk. His notes were published in 1655 as *The Most Notable Antiquity of Great Britain, Vulgarly Called Stoneheng, on Salisbury Plain.* He thought it was a Roman construction and likened it to temples he knew of in Tuscany. At about the same that infamous royal favourite George Villiers, the Duke of Buckingham, also visited the site and excavated a large pit in the centre of the monument in order to topple one of the sarsen stones (55), also significantly undermining its companion (56), whic hby 1660 was leaning over at an angle of 75 degrees . Buckingham was interested enough in pursuing these inquiries to offer to purchase the site from its owner, a local gentleman, but he was rebuffed. In 1663, Walter Charleton wrote a book on the monument, *Chorea Gigantum* ("giant's dance") which speculated that Stonehenge was a royal court or palace constructed by the Danes around the time of King Alfred. Charles II also visited the site (on his way into exile, 1651) and was entranced by it, pausing in his flight to "reckon and re-reckon the stones." After his restoration in 1660 he ordered the renowned Stuart diarist John Aubrey to conduct fresh investigations at the henge. Aubrey already knew the site well, though he considered it be be inferior in its plan and construction to the Avebury Circle. He was the first to attempt to compare Stonehenge to other ancient stone circles and also the first to associate it with the druids, speculating that it was an ancient religious temple (still a popular supposition even today, of course). It's also to Aubrey that we owe the discovery of the "Aubrey holes" inside the bank encircling the henge. Modern archaeologists believe these had been used to anchor wooden poles that had once surrounded the henge. **The Hanoverians** Georg Keysler, a German traveller who visited Britain in the 1720s, saw Stonehenge and thought it had been constructed by Saxons. Organised excavations at the henge date to 1723, when Lord Pembroke (a descendant of the earl of the 1620s) had trenches dug around the altar stone at the centre of the monument and discovered numerous flints. Finally we come to William Stukeley, another antiquarian, whose once-battered reputation has been undergoing quite a revival in recent years, It was Stukeley who first correctly suggested that the stones were of far greater antiquity than earlier thought, putting its construction at about 480 BC (still out by around 2,000 years, but by far the best and most thought-out guess made to that time – and that can be said to have ushererd in the modern period of Stonehenge studies.) He also identified the stones that make up the henge as coming from at least three different sources, and made the first serious efforts to place Stonehenge within the wider context of its surroundings. Of course, while all this antiquarianism was going on, the local people of Salisbury Plain were also interacting with the monument - generally to despoil and quarry it for homes and road surfacing, but also to chip away at the stones to carve out bits of rock that were considered lucky charms. Examination of successive images of Stonehenge show the loss of some stones and the toppling and fracturing of others, as a result of this small scale but ongoing work. Other forces were also at work in this period, however; the loss of one 60-ton sarsen was caused by a band of "gypsies" who sheltered at Stonehenge in the early 1790s while waiting for a local fair to begin. They dug a shelter for themselves against the stone and this was enough to weaken the foundations and bring it down a couple of years later. *Sources* Burl, Aubrey. *Stonehenge: A Complete History*, 2006 North, John. *Stonehenge*, 1996 Pitts, M. and Bayliss, A. and McKinley, J. and Bylston, A. and Budd, P. and Evans, J. and Chenery, C. and Reynolds, A. and Semple, S. J. (2002) ’An Anglo-Saxon decapitation and burial at Stonehenge.’, *Wiltshire Archaeological and Natural History Magazine*, 95 . pp. 131-146. Richardson, R.C. "William Camden and the re-discovery of England." *Trans. Leics. Arch. and Hist. Soc.* 78 (2004) pp.108-123.

what the meaning is of the different "alarm" fires. for example, a major fire is known as a "5 alarm"

It's a system to describe how many resources are being devoted to a fire. More alarms means more trucks and firefighters are responding. _URL_0_

antibodies and antigens.

Immunology is one of those topics that can get extremely tedious and complicated. So, since I don't know how much detail you're looking for exactly, I'll just start with the basics and you can ask questions from there if you like! * Antigen ("against life") = anything that is harmful to you and triggers an immune reaction. * Antibody (*probably condensed from some longer phrase such as "anti-toxic body")* = Any of a bunch of proteins of the immune system that seek out and destroy antigens. They also have other functions including helping to trigger other antibodies to help them attack an antigen.

In many medieval movies such as Braveheart there are often scenes with military commanders shouting motivational speeches to entire armies on the battlefield without using voice amplification of any sorts. In real life, were they really able to hold speeches like that and is this how it was done?

The answers are further back in time than you're asking about here, but while you're waiting this thread might interest you: [*Do the speeches we often see before a battle in most literature and visual performances have any historical basis. Did the kings and generals leading an army ever give a speech to rally the troops. Or is this just a modern romanticism?*](_URL_0_) featuring /u/Thrasyboulus, /u/Celebreth, and /u/Quietuus

the concept of english "tea".

In Ireland, "tea time" or "having your tea" is actually a colloquial term for the evening meal, as well as the actual drink. And to make it even more confusing, many refer to lunch as "dinner", and the dinner as "tea". But pasically, praesartus is correct. People routinely drink tea throughout the day in both the UK and Ireland. As in at work or college, the occasional "tea break" where someone makes a pot of tea and everyone has a cup is pretty much as common as a smoke break for those who smoke. If someone comes in to your house, even just to drop back a DVD they'd borrowed, it's pretty common to have a cup of tea with them. Tea would generally be included in the "time to stay for a drink?" question if someone's just dropping by, which in the US seems to be confined to having a beer. Over here, "staying for a drink" can mean anything from a cup of tea to a glass of whiskey. :p

what makes cloud black?

Sunlight comes from above, and it can only go through so much moisture before it's all blocked. Therefore the gray areas are just the thickest areas of cloud coverage. The clouds themselves are actually white throughout, just varying levels of sunlight.

What's a piece of knowledge from your area of historical study that you enjoy telling people about, and why?

Going through Victorian newspapers, I've come across a lot of strange and transient cultural phenomena that never made it into the history books. For example: monkey parachuting. No, seriously. The case I came across was in 1851. A hot-air balloon went up from a park in London, and a monkey was tossed out with a parachute attached, falling into the back garden of a Mr Lovelock. The monkey was fine, but Lovelock was beaten up when a gang barged in his front door to get their monkey back. The best thing is that the papers refer to this kind of bizarre balloon stunt as a fairly common nuisance. Apparently, as well as all the other problems in Dickensian London, you had to keep an eye out for animals descending from on high.

is cryogenic sleep possible?

Not yet. When ice forms, it forms tiny crystals. These tiny crystals tend to pierce the cell walls of animal cells. As you can imagine, having all of your cell walls shredded is fatal. There are a few exceptions. Some species of frog, by modulating the solute concentrations (amount of dissolved stuff, like sugar) in their bodies, can survive a freeze without seeming to undergo too much trauma. The way they're able to do this is that they prevent actual freezing in most of the vital tissues, because freezing points are lower where solute concentrations are higher.

Is our solar system considered normal? What other variations are there? Stars with rings? Stars as planets? Special orbits?

Our detection methods don't work well for systems that look like our solar system. We don't know yet. What we know for sure: There are many systems that look completely different. Planets much closer to the star, much more distant, inner gas planets and outer rocky planets, planets in double star systems, planets as hot as some stars, ... * Transits and related methods are more likely for planets near the star. We found many systems with planets very close to the star - often closer than Mercury. * Radial velocity measurements work better for heavy planets close to the star. We found many systems with that. Imagine Jupiter, but closer to the Sun than Mercury. * Direct imaging works best for very large planets with a very large separation to the parent star, much larger than the planets in our system. * Microlensing and other approaches don't find enough for good statistical analyses.

we have so much water continually running-- streams, rivers, lakes-- where does it all come from and how?

Well, you have this thing called watersheds. Watersheds are basically an area of land in which we can safely predict that a healthy amount of the water available in this land will flow into a specific body of water, like lakes or rivers. So although you don't see rainfall specifically landing in the river, it will make its way there eventually as long as it lands within the watershed. Mind you, watersheds tend to be huuuuuuge, hundreds of square miles. The Mississippi's watershed, for example, runs from Idaho to Pennsylvania and from Canada to New Orleans. Also, we can't forget about groundwater, which is about 20% of the world's freshwater. So there's fully 1/5th of our freshwater that's never visible to us - thus, the idea that it's all spring water isn't as crazy as it sounds. Another large source of water is ice, snow, and glaciers. Remember, glaciers are so huge that they literally flattened the northern half of North America. Glaciers are so incomprehensibly big that it may be hard to imagine just how much of our water supply comes from their slow melting.

how are certain roads "aircraft patrolled" for speeding?

This is one of those stupid things I think about every time I drive past one of those signs, and never think to research when I'm home. Next stop, Google.

how can a bunch of 0s and 1s create everything digital?

The whole subject is a bit too complicated and a bit too deep for a short ELI5, but I'll give a stab at the gist of it. The reason why computers work (at least in the vein of your question) is very similar to the reason why we have language -- written, spoken, etc. What you're reading right at this very moment is a complex system (language) simplified to symbols on the screen. The very fact that you can read these words and attain meaning from them means that each sentence, each word, and each letter represent a sort of code that you can understand. If we take an apple for example, there are many other ways to say that in different languages. Manzana. Pomme. Apfel. And so on. Codes -- some symbol maps to some concept. In the context of computers, well, they can only "understand" binary. Ones and zeros. On and off. Well, that's okay, because we can map those ones and zeros to codes that we (humans) care about. Like 101010111 could represent "apple" if we wanted it to. So we build these physical circuits that either have power or don't (on and off) and we can abstract that to 1's (power flowing through that circuit) and 0's (no power flowing through it). This way, we can build physical chips that give us basic building blocks (basic instructions it can do) that we can leverage in order to ultimately make programs, display stuff, play sounds, etc. And the way we communicate that to the computer is via the language it can understand, binary. In other words, in a basic sense, we can pass the processor binary, and it should be able to interpret that as a command. The length of the binary, and what it should contain can vary from chip to chip. But lets say our basic chip can do basic math. We might pass it a binary number: 0001001000110100 but it might be able to slice it up as 0001 | 0010 | 0011 | 0100 -- so the first four, 0001, might map to an "add" command. The next four, 0010, might map to a memory location that holds a number. The third group of four might be the number to add it to. The last group might be where to put it. Using variables, it might look like: c = a + b. Where "c" is 0100, "a" is 0010, "b" is 0011, and the "+" (addition operator) is 0001. From there, those basic instructions, we can layer abstractions. If I tell you to take out the trash, that's a pretty basic statement. If I were to detail all the steps needed to do that, it would get a lot longer -- take the lid off the can, pull the bag up, tie the bag, go to the big garbage can, open the lid, put the trash in. Right? Well, if I tell you to take out the trash, it rolls up all those sub actions needed to do the task into one simple command. In programming, it's not all that different. We layer abstractions to a point where we can call immense functionality with relatively little code. Some of that code might control the video signal being sent to the screen. Some of that code might control the logic behind an app or a game. All of the code though, is getting turned into 1's and 0's and processed by your cpu in order to make the computer do what is asked. If you want to learn more, I highly recommend [Code by Charles Petzold](_URL_0_) for a much more in depth but still layman friendly explanation of all this.

What was the reasoning for the Pancho Villa Expedition? How was Pancho Villa able to evade U.S. capture for so long despite the large force sent to stop him?

Villa's motives for the Columbus raid seem to have been various. He wanted to take revenge on the American arms dealer who had taken money for supplies and neither given him the arms or returned the money. He was increasingly angry at the way the US professed to be neutral in the Revolution, but actually aided Carranza. He also hoped to gain arms and supplies. He achieved none of these. Instead, instead of easily overcoming what he'd been told was a garrison of 50 US soldiers , he encountered one of 600. Instead of opening fire in a surprise attack on the barracks, Villa's troops opened fire on the stables. As a result of a vigorous defense and counter-attack, Villa lost men- especially officers- and was forced to retreat back to Mexico empty handed. The Punitive Expedition was ordered by President Wilson after Villa's raid, intended to find Villa and his army. About 5,000 soldiers, it had the initial tacit cooperation of Carranza, who helped supply it by railroad. Despite the advantages of force and supplies, it was however trying to operate in Chihuahua, Villa's home: and so Villa knew the territory. Chihuahua was/is also the biggest state in Mexico, sparsely settled and with rough terrain, so capable of hiding armies. There was a great deal of local resentment to having a US army operating in Mexico, despite Pershing being under strict orders to treat civilians with great respect. Pershing soon discovered that no one would supply his army with information about Villa's whereabouts, and rightly suspected that the locals were also constantly supplying Villa with information about Pershing's. Villa also discovered that Carranza's troops were also often more sympathetic to his army than to the Americans, and would sometimes look the other way when his men were in an area. When Villa was wounded in the knee, he essentially dispersed his units and hid in a cave for two months. This also briefly created the impression that he was possibly dead, and the Expedition therefore successful. Pershing had had some experience in fighting guerrillas in the Philippines and pretty quickly assessed the situation, saying that a much longer time would be needed, and more resources, if Villa was to be found. But as the Expedition continued, Carranza became himself more hostile to the US, more hostile to having the US Army on Mexican territory and less cooperative, and his troops began to show some real armed resistance to the US, for example blocking them at Parral. Things might have escalated further, but neither Wilson or Carranza wanted to enter into a war: Mexico was too divided and weak, and the US was anticipating being pulled into WWI in Europe for which it would need an entire army. After about a year of futility, Pershing was put back into a more defensive position along the border, and eventually all US forces left Mexican soil.

(In)Accuracies in Asbury's "The Gangs of New York"?

I'm not going to answer your question directly, and I apologize since this will be a top level post, but I don't know that you will get any replies again. You're asking the people here to do your homework for you in a way. But I'll give you my thoughts as someone interested in the period. [*The New York City Draft Riots*](_URL_0_) by Iver Bernstein has been on my reading list for a while. [Here is a review of it](_URL_1_) on JSTOR if you have access. It covers the riots portrayed in *Gangs of New York* (at least the movie, I haven't read the book) and also discusses the religions and politics working in New York at the time. This would be where I would start off, partly because that's the most interesting part of the American Civil War to me, and partly because those riots were a pivotal part of the plot (again, of the movie), and something that is confirmed historical. It also covers the fundamental issues surrounding the riots. Now, keeping in mind, I haven't read either book. I read reviews of the Bernstein book but I haven't quite gotten to it on my list yet. But I looked for it and picked it up partly because of the movie, which I know is different than the book, so take that as you will. So that's where I would start.

Is medieval French as incomprehensible to modern French speakers as Medieval English is to modern English speakers?

Might be worth a cross post to /r/linguistics ?

the 9 pieces of 8 in pirates of the caribbean

Each of the nine Pirate Lords agreed to hold a piece of eight to be presented during a meeting of the Brethren Court, though the term came to apply to a variety of items and trinkets as the pirates found themselves short on money, simply keeping the original term as it sounded more 'piratey'. Each piece of eight reflected something about the lord who possessed the piece, and altogether, the nine pieces were used to bind the sea goddess Calypso to a human form, after Davy Jones informed the Brethren on how to capture her. _URL_0_

Colonization of Venus

As I recall, the theory was to use balloons of some sort to keep one aloft amongst the clouds. The big problem was corrosion, something that I have yet to read a solution for. I'm actually curious about what one would do for food, colonial expansion, the initial costs to doing this, and harvesting resources from Venus so as not to rely on sending supplies from Earth. I would put the colonization of Venus as possible, but not probable.

Is atmospheric noise truly random?

Atmospheric fluctuations are not truly random, they're just extremely chaotic and unpredictable. Radioactivity is different. As far as we can tell, it really is random when a radioactive particle will decay.

how do scientific research articles get published? how do we know their results aren't faked? what exactly are scientific journals and how do researchers get revenue from publishing their research work?

When an article gets submitted they have a lot of people look at it and similar data in order to publish it. It generally takes months. And a lot of research is funded either at a government or private level.

What is the most inaccurate and accurate movie regarding your field of study?

"20,000 Leagues Under the Sea" 20,000 Leagues = 111,120 km Diameter of the Earth = 12,769 km

Why is facial hair such an important thing in the Abrahamic religions, and does it have importance in any Eastern religions?

Hi, long-time lurker. But I think I can actually contribute a bit to this! ___________________________________________________________________ **Banned Beards** I actually don't know too much about the Jehovah's Witnesses, so I won't try and touch on their beliefs and practices. Mormons (LDS), however, I do know a bit about. For the LDS Church and its members, **a lack of facial hair is more cultural than spiritual**; there's no commandments or doctrine that insist men be clean-shaven. The early Presidents of the LDS Church, from [Brigham Young](_URL_4_) to [George Albert Smith](_URL_10_) (#2 through #8), had varying degrees of facial hair, and many of the other leaders of the LDS Church ([early Quorum of the Twelve Apostles and First Presidency](_URL_7_)) sported what look like quite stylish beards for the time. Instances within the LDS Church where facial hair *is* banned do exist. The two that come to mind are (1) young men serving as full-time missionaries and (2) students at Brigham Young University (BYU). From the official *Missionary Handbook*: > Keep your hair relatively short (not clipped too close) and evenly tapered. Extreme or faddish styles— including spiked, permed, or bleached hair or a shaved head—are not appropriate. Sideburns should reach no lower than the middle of the ear. (See the pictures of a missionary haircut included with your call packet.) **Elders should shave each day.** > ([Missionary Handbook: Missionary Conduct](https://_URL_5_/manual/missionary-handbook/missionary-conduct?lang=eng), emphasis added) BYU's Honor Code contains a similar requirement that ["men are expected to be clean-shaven; beards are not acceptable."](_URL_0_) According to the Salt Lake Tribune, BYU President Ernest Wilkinson banned beards in 1969. (Salt Lake Tribune, [The History of BYU's Honor Code,"](_URL_1_) 29. Oct. 2016.) Both bans are addressed by Dallin H. Oaks, who was President of BYU at the time (he now serves as a member of the LDS Church's highest governing body). > "Our rules against beards and long hair have the same purpose as the requirements our Church makes of its missionaries. In this university, which is largely supported by the tithes of faithful members and which stands as a beacon of Latter-day Saint values, we wish to avoid an appearance that has become associated with rebellion and rejection of values we hold dear. A recent book by Jerry Rubin, the clown prince of the hippy movement, gives this vivid characterization of the meaning of long hair: > > "'Long hair is communication. Young kids identify short hair with authority, discipline , , ,—and long hair with letting go, letting your hair down, being free, being open. Wherever we go, our hair tells people where we stand on Vietnam, Wallace, campus disruption, dope. We’re living TV commercials for the revolution. > > "'Long hair is the beginning of our liberation from the sexual oppression that underlies this whole military society.'" [Jerry Rubin, Do It, pp. 93, 95–96] > (Dallin H. Oaks, "Be Honest in All Behavior," 30. Jan. 1973, [_URL_12_](_URL_9_).) Similarly, in a 1971 issue of the LDS Church's publication for its teenage members, the *New Era*, Oaks was again cited as saying: > The rule against beards and long hair for men stands on a different footing. [. . .] Unlike modesty, which is an eternal value in the sense of rightness or wrongness in the eyes of God, **our rules against beards and long hair are contemporary and pragmatic. They are responsive to conditions and attitudes in our own society at this particular point in time.** > There is nothing inherently wrong about long hair or beards, any more than there is anything inherently wrong with possessing an empty liquor bottle. But a person with a beard or an empty liquor bottle is susceptible of being misunderstood. Either of these articles may reduce a person’s effectiveness and promote misunderstanding because of what people may reasonably conclude when they view them in proximity to what these articles stand for in our society today. > **In the minds of most people at this time, the beard and long hair are associated with protest, revolution, and rebellion against authority. They are also symbols of the hippie and drug culture.** Persons who wear beards or long hair, whether they desire it or not, may identify themselves with or emulate and honor the drug culture or the extreme practices of those who have made slovenly appearance a badge of protest and dissent. In addition, unkemptness—which is often (though not always) associated with beards and long hair—is a mark of indifference toward the best in life. > (Dallin H. Oaks, "Standards of Dress and Grooming," Dec. 1971 *New Era*, [_URL_5_](https://_URL_5_/new-era/1971/12/standards-of-dress-and-grooming?lang=eng), emphasis added.) The prohibitions of the LDS Church on facial hair are a product of its members' desire to be ["in the world, but not of the world"](_URL_6_); a push by their leaders to separate themselves from "worldly things" but remain ["the light of the world."](_URL_2_) And in the late 1960s and 1970s, when counterculture in America was marked a preponderance of beards and facial hair in general, the leaders of the LDS Church wanted their young adult followers to keep a safe distance from counterculture movements that espoused beliefs or practiced activities that did violate LDS commandments, such as drug use or sexual promiscuity. And even though society has moved beyond that, with facial hair rapidly becoming mainstream over the past several years, the unofficial stance of the LDS Church has not drastically changed. (It is worth noting that several publications maintained by the LDS Church have moved towards a more lenient stance, such as the LDS Employment Services' recommendation for ["Dressing for Success"](_URL_3_) suggest that job-seekers "follow appropriate business culture for facial hair.") **TL;DR:** Mormons don't have facial hair because of the association it had in the 1960s/1970s with practices they forbid, such as drug use.

Was there ever any movement to have the United States switch to driving on the left side of the road?

Also, was/is there any movement to have the UK switch to driving on the right side of the road? I know that some countries have made a switch, so the UK possibly could too.

What could happen to East Germans whose family escaped to the West?

It was illegal to leave the GDR without a special permit, which also stated how and when you had to return. If you failed to do so, you risked criminal prosecution according to § 213 StGB-DDR, up to 5 years in prison (extended to 8 years in 1977). This includes attempts to flee, thus she could face anything from a fine to 8 years in prison for being accomplice in an attempt to flee. If the authorities assumed that she organized (or helped to organize) her husbands escape, she could also be persecuted according to § 105 StGB-DDR, in which case she could face between 2 and 15 years in prison (later extended to lifelong prison). Sources: § 105. Staatsfeindlicher Menschenhandel § 213. Ungesetzlicher Grenzübertritt Strafgesetzbuch der Deutschen Demokratischen Republik (StGB) vom 12. Januar 1968 in der Fassung vom 7. April 1977. These are only the direct criminal persecutions though. If she had known about the attempt, even if she were only likely fined, she would have risked to be deprived of her (future) children's custody or be forced to give their children up for adoption. Source: Marie-Luise Warnecke: Zwangsadoptionen in der DDR, Berliner Wissenschaftsverlag, Berlin 2009 Furthermore, she and potential children (or other close relatives) risked occupational bans. In that case, she would only be allowed to work in specifically permitted jobs, which carried the risk of being prosecuted according to § 249 StGB-DDR, which could be punished with up to 5 years in prison. Access to higher education for her and her close family could also be limited or completely denied. Source: Danuta Kneipp: Berufsverbote in der DDR? Zur Praxis politisch motivierter beruflicher Ausgrenzung in Ost-Berlin in den 70er und 80er Jahren. in: Potsdamer Bulletin für Zeithistorische Studien Nr. 36-37/2006, Seite 32 ff § 249. Gefährdung der öffentlichen Ordnung durch asoziales Verhalten. Strafgesetzbuch der Deutschen Demokratischen Republik (StGB) vom 12. Januar 1968 in der Fassung vom 7. April 1977.

Some economists consider Social Mobility to be more important than inequality in a society's health. Apart from the United States, is there any civilization is considered to have more Social Mobility than any others? Why do theorists/historians think this is so?

Sorry, we don't allow [throughout history questions](_URL_0_). These tend to produce threads which are collections of trivia, not the in-depth discussions about a particular topic we're looking for. If you have a specific question about a historical event or period or person, please feel free to re-compose your question and submit it again. Alternatively, questions of this type can be directed to more appropriate subreddits, such as /r/history or /r/askhistory.

Is it theoretically possible to surround the sun with solar panels and “harness” the sun?

There's a thought experiment, called a [Dyson Sphere](_URL_0_) (after physicist Freeman Dyson who popularized the thought experiment), that does this. The engineering required to achieve this is far beyond our current capabilities, making it a highly theoretical concept.

Booker T. Washington's views made widespread changes to education for African-Americans, but did his views affect education for white people today?

One possible thread to investigate is the relationship between Washington and contemporaries like John Dewey and Ella Flagg Young. There are some interesting primary sources that speak to the time the two men were in the same place at the same time and how those interactions lead to changes across the system.

Can you get vitamin D from the moon/moonlight?

Based on values obtained from the Wikipedia for Moonlight and Sunlight, the light of the sun can vary between 120,000 lux and 400-200 lux depending on atmospheric conditions. The average lux value of moonlight is around 0.1. With that in mind while it may be theoretically possible to utilise moonlight to produce vitamin D it's unlikely to reach anywhere the 'therapeutic' dose that the body requires.

What does marinating a meat (chicken, fish, steak) in lemon/lime/orange juice do to the meat?

An acidic environment will denature proteins - like heat does. That's the reason you begin to see white in chicken like if it's cooked. It's the principle behind [ceviche](_URL_0_).

how do government officials justify trading 5 terrorists for bowe bergdahl, who's now facing charges, but not making trades for all the aid workers that have been killed?

The government has a responsibility to recover American soldiers. The government does not have an equivalent responsibility to secure the release of people who voluntarily entered a combat zone.

How can the gravitational field of an object slow another object if it cannot expend energy?

The asteroid loses kinetic energy and gains potential energy.

steubenville rapists

This ~~[Blog](_URL_1_)~~ gives a pretty good run down of all the controversy. *Edit for summary: Although two students were convicted, evidence was uncovered that there were many more people involved in the rape and subsequent cover up. From other students who tweeted jokes about the girl while she was being dragged from party to party; to coaches, teachers, and law enforcement turning a blind eye or even encouraging the victim to keep quiet. Apparently this isn't an isolated incident for Stubenville, in light of all the news coverage other victims have come forward. There's also coaches giving drugs to students, student party apartments, and underground gambling on high school sports. Also, here is the link to the original [Local Leaks](_URL_0_) site, it has a bit more videos, info, and references.

why does alprazolam stay in your system for 1-6 weeks when the half-life is always the same?

There are going to be three main reasons for this. First, the half-life of the drug is the time for half the material to break down, meaning there is rare chances for some of the material to last longer than usual. It's an estimate, not a guarantee. Second, and more important, is the fact that drugs like Alprazolam break down into secondary products, 4-hydroxyalprazolam and α-hydroxyalprazolam, which themselves can be broken down into other metabolites, before being excreted in the urine. Like most drugs, the compounds can be deposited into fats or other tissue, leading to a lingering timeline of release, especially when taken over a long period of time. For example, if you take 1 dose a day, and 1/4 remains in your body after 1 day, then on Day 2 you would have 1.25 dose-equivalents in your body. On Day 3, it would be 1.31, to a limit of 1.333 dose-equivalents in the blood, plus whatever is stored in your tissues. The third main reason is going to be drug-interaction. Using a CYP3A4 inhibitor, like Tagamet (cimetidine) can delay the intake of Alprazolam into the liver, which would delay the breakdown of the drug, which would allow it to stay in the body longer.

i'm sitting at a stoplight and there are several cars in front of me. they all have there blinkers going at different intervals, except for a short period of time when they completely coincide. what is happening??

If car A's turn signal is blinking every 1.3 seconds, and car B's signal is going every 1.4, they won't match up. However, since one car's signal is faster than the other's, it will eventually 'catch up'. While they won't be perfectly in sync, they'll appear to blink together for a second or two before the gap between increases a sufficient amount.

why tv shows and movies can get the rights to show certain video games, but never the actual sounds/ music.

A lot of music, especially, is licensed from someone else for the game. So if they're showing Tony Hawk's Pro Skater 2, they have permission to show the video game. If they want to play the music ("When Worlds Collide" - Powerman 5000), then they have to get permission from Powerman 5000 or their agent/record label to play that music.

Was it possible in 1943-45 Nazi Germany for a fit, early 20's man to NOT be in the military? What one would have had to do to avoid service?

Sort of a tongue-in-cheek follow-up question. Could you be fit early 20s Jewish man and serve in the military and is there any difference in the service required? I'm thinking analogous to African Americans serving in WWII.

Strange black rock/mineral or meteor(?) I found, can someone identify it?

Notice the piece is flat and unrounded. I believe it is a vein, broken free from it's gangue. The mineral is probably an iron carbonate (siderite?), possibly psudomorphic after limonite - crushed powder is probably ruddy brown and it would fizz in 10% HCl. These guys often form in hydrothermal settings around intrusions or in extensional settings; given how undeformed it is (except a bit of brittle fracturing visible in cross-section), I'd suggest the latter. re, siderite pseudomorph after limonite: _URL_0_ Definitely non-meteoritic.

How "thick" would a gamma ray burst be?

Gamma Ray Bursts have a usual duration of some seconds to some minutes; the avarage of "normal" gamma rays is a bit more than half a minute. Some of them however had a lifespan of some minutes to hours, with a record of some weeks. Those are very rare, however. Asking for a planet killer, there is no difference to other Gamma Ray Bursts in duration, but in distance. Close by GRBs can irradiate the atmosphere much stronger and that's all. So all GRBs are potential planet killers, however most of them are simply too far away to be an actual threat for us.

why do drift cars turn their wheels in the opposite dirrection they need to go?

The front wheels are not pointing in the "opposite" direction from where they need to go. They are pointing **exactly in the direction they need to go**. If you examine a video closely, you'll find that the front wheels don't slip - they're following right around the curve. It is the back wheels that are swung outwards, thus the car is pointing further into a turn than it is going.

How do we measure time in circuitry?

There's a great [engineer guy video on quartz clocks](_URL_0_) that's worth watching. Basically there are two sides to the system. First, you create a very small "tuning fork" of quartz, which has a very precise resonance frequency (typically 32,768 Hz, for reasons that will be explained). Quartz is piezo-electric, when a voltage is applied it will vibrate and when it vibrates it will generate a voltage. This means that the tiny quartz tuning fork will generate a series of electric pulses at a frequency of 32,768 Hz. Second, a small digital chip is paired with this pulse, it does very little, most of what it does is add. With every pulse from the quartz the chip adds 1 to a count. When it reaches 32,768 it triggers a signal indicating that one second has passed. That signal can then be used in other adders to add up seconds, minutes, hours, etc. In this way a digital clock can keep track of the passage of time. 32,768 is chosen because it is precisely 2^15. Meaning that starting from zero a simple 14 bit adder can count up and once it gets precisely to 32,768 it will trigger overflow/carry over to the 15th bit, which can be used as a signal for keeping track of seconds. Also, the size of a quartz crystal tuned to 32,768 Hz is small enough to be compact, cheap, and use a low amount of power while still being large enough to be produced with incredibly high precision while also producing sound (though very faint) in frequencies that humans can't hear.

Why do certain things that shock/scare us give us the jitters/shock which basically makes us useless and other things give us super strength(hysterical strength)?

This happened to me on my motorcycle during an near miss crash with another vehicle. I had the jitters and couldn't immediately lift my bike, it's like my mind was so all over the place I couldn't focus my mind enough to continuously drive my muscles to lift my bike. Strange feeling, the best comparison I can make is it's like trying to lift something heavy while laughing hysterically.

can weather or storms actually be controlled or man made? if so, to what extent and how?

Short answer: yes to a very limited extent Longer answer: not in any realistic, safe, or controllable way. Weather is super complicated and often pretty hard to predict. Imagine if you had a big bowl of water and you kept sloshing it around, meteorology is guessing/analyzing where individual waves will form. You can effect the weather by large releases of heat or particulates, but both have enormous ecological impacts and are expensive. Also if you mess with the weather in one place you tend to fuck over somewhere else (a la butterfly effect). So generally its not safe, cheap, or smart, but we could technically do it minorly.

How does one computer share its private key with another computer?

The idea of public-key cryptography is that the first computer shares the public key, and keeps the private key to itself. The second computer encrypts data (typically, a randomly generated session key for symmetric cryptography, which is much faster than public-key cryptography) with the first computer's public key and sends it to the first computer. The first computer decrypts the encrypted data with its private key, which no one else can do. Edit: I should've said "The basic idea"; real-world protocols are of course more complicated.

why don't companies like nintendo and sony put their retro games on steam?

Companies like Nintendo and Sony already have their own game distribution platforms and they're generally very wary of using other distribution channels. If they distribute games through Steam, they ultimately would have to give up lots of control over the distribution and pricing of the games. Furthermore, Steam will take a cut of the sales revenue that Sony/Nintendo are probably unwilling to give up. Also, Steam already acts as a competitor in some ways since users may opt to buy video games on Steam/PC rather than consoles, so that's just another reason these companies may be unwilling to negotiate deals with PC distribution platforms like Steam.

What specifically is stopping people from finding an analytical solution to the Navier-Stokes equations under turbulent conditions?

It's not my field, so I can't say too much so I will just paraphrase a couple points that Terry Tao made in a [Post](_URL_0_) about why it is hard. (If I say anything horridly wrong, please correct me.) He says that there are three general strategies to solving these kinds of nonlinear PDEs. * Find explicit solution. * Perturbation * Controlling a solution based on some global quantity (like Energy) We can bet that no one is going to randomly find an explicit solution, it would take a great deal of luck and the arbitrariness of the initial conditions makes this not likely. Perturbation is when you slightly broaden the problem with an artificial parameter. Tao says the main issue with this is that no matter how small the parameter is, the Navier-Stokes equation behaves completely differently between perturbed and non-perturbed versions. When you perturb, the equation behaves a lot like a linear equation, which is not the case in when you don't. The issue with the third method is that no known quantities either do scale very well and this means that we lose control over the finer details of the solution, or they can't control a solution. This means that there are three possible routes to figuring this problem out: * Get really lucky and find an explicit solution * Create a new kind of global quantity that behaves well that we can use to control a solution * Invent a new method entirely that doesn't rely on any of the known methods. All three are not going to be easy. There's no way that we can rely on the first option. The second condition is hard because the Navier-Stokes breaks down every known quantity that we can try to track, because it's pretty abusive to geometry and chaotic at all scales and there aren't any quantities from physics besides energy that we can rely on and it doesn't help us. But, you never know, as he says that the Poincare Conjecture (the only Millenium Prize Problem to have been solved) was solved by controlling a new kind of variable, though it was geometric in origin and the Navier-Stokes equation does not behave well in that aspect. That leaves the third option. This is hard because instead of controlling solutions through some quantity, it is possible for quantities to blow up and not behave well under scaling. I guess the moral is that it allows for very chaotic solutions and that really messes shit up.

What distinguishes alpha, beta, and gamma radiation from other types of ionizing radiation? Why doesn't neutron radiation fall into the same category?

The "α, β, γ" classification of radiation was made by Rutherford and Villard back around the turn-of-the-century. It was basically empirical (on the basis of how far they penetrated through matter), and they didn't really know what these things were. I.e. they didn't know that gamma rays were actually the same thing as Röntgen's "X-rays", that "beta rays" were actually the same thing as "cathode rays" which JJ Thomson had (at the time) postulated to be electrons. Neutrons and neutron radiation weren't discovered until much later, around 1930. So neutron radiation got a better, more descriptive name than the other three. But neutron radiation _is_ usually considered ionizing radiation. It can cause ionization in a number of ways. First, by being absorbed by a nucleus (or just deflected by it) which can impart enough energy to cause ionization. Second, free neutrons decay into energetic protons and electrons (and a neutrino), both of which are directly ionizing. Third, it can cause it indirectly by transmuting stable nuclei to radioisotopes after being absorbed. I suspect it's mentioned less often, perhaps in part just because of the history here, but also because neutron emission is much less common form of decay compared to the other three. Alpha/beta/gamma is a concern whenever you deal with radioisotopes, but not so much neutron radiation unless you're dealing with a nuclear reactor or bomb.

how was code invented before code?

you programmed in binary by flipping toggle switches. after that came punch cards.

if you lose your genitals will you lose your sex drive too?

No. Your sex organs are not the only "source" for your sex drive. It affect it in some ways, although there is no consensus about how much. In losing them, you'd fail to act upon these desires, but your capacity to feel them would not disappear completely.

What would it take to make a virus like Ebola or HIV airborne?

I think there already is at least one strain of ebola that is airborne, but is harmless to humans. Ebola Reston or something. Thank you Hotzone.

What is the full chemical process when tea is brewed with tea leaves, a pot and a kettle?

It's mostly just dissolving solid mateirals into the hot water. Then, they diffuse. So, chemically, it's pretty much the same as mixing sugar, salt, whatever into water. The compounds become solvated and form hydrogen bonds, then can diffuse through the water.

could someone explain why astronomers use julian dates?

Astronomers like Julian dates because they make math simpler for events that don't have anything to do with the Earth year. If a variable star has a period of 270 days, it is a lot easier to add subtract 270 than it is to count through all the months to figure the exact date. Why 4713 BC? It is pretty arbitrary, but it is useful because it predates any historical events, so you don't have the BC/AD problem. The reason for that particular date is pretty obscure. When they came up with it in the 1500's, there was a 15 year cycle, a 19 year cycle, and a 28 year cycle astronomers cared about. 4713 BC was the last time all three cycles started at the same time.

placebo side-effects - i think i understand the placebo effect but how can your body create a side effect?

Basically if you believe hard enough, your body will try and make it true. Obviously it can’t do as much as a drug for testing can do, but the placebo effect is quite a powerful thing.

Why is a telescope not called a macroscope if its the opposite of a microscope?

If you look at the etymology, 'tele' is Ancient Greek for 'far away'. So a 'telescope' is something used to look at things 'far away'. If it was a 'macroscope', it'd be used to look at big things.

could someone eli5 why java is so insecure?

Because Java is everywhere! The more popular something is the more it will be exploited.

4-dimensional space and hypercubes?

Let's first get a grasp of what a "dimension" is in geometry. "Dimension" sounds like a big word and is sometimes used to mean something like "world" or "universe" when people talk about "alternate dimensions" and so on, but it's actually a fairly simple concept in geometry and mathematics in general. Let's have a look at some examples to figure it out: Is there such a thing as a 0-dimensional object? Yes! A point. Here we are talking about the geometrically perfect point. So perfect that we cannot even draw it with our imperfect tools. If you try to measure how wide a geometrically perfect point is, you can't. It's just a single pixel. It is so tiny that it has no width/height/breadth, you can assign no number to it. It has no dimensions. Now, how can you make a 1D object from this? The answer: You add another point and connect both with a lot of really close points to form a line (it's actually an infinite amount of points). Unlike the point, you can measure a line with a ruler, but this only works in one "way", along the line's width. A geometrically perfect line has no height and no breadth. It is a 1-dimensional object, you can only measure it in one way, in one dimension. Why is the dimension we measure the line's width? Well, that's just convention, a name we decided to give it. It really does not matter if you call that measurement width, breadth or height. That's just the way people decided they would call it. Let's progress to 2D now. To make a 2D object you take the line from before and make a copy of it a little further away. Then you connect both lines with additional lines. The object you created is an area. An area is a 2-dimensional object, so you can measure it in two ways. You can measure its width and its breadth. Further to 3D: Take the area from before, add a copy of it and connect both areas with additional areas. Suddenly, you have a volume, which is a 3D object. You can measure width, breadth and height of this object, because it has three dimensions. Notice how for every transition to a higher dimension, we used several copies of the object in the lower dimension to create the object in the higher dimension. To make a line we used a bunch of points. To make an area we used a bunch of lines. To make a volume we used a bunch of areas... so mathematicians figured out: To make a 4D object, we need to use a bunch of 3D objects! This is how a hypercube is drawn. You take a 3D cube, and place another 3D cube near it. Then you connect both cubes using other 3D objects. This was all probably a bit difficult to visualize in your head, so [here's a nifty animation](_URL_1_) showing you what I just described in this post. Also, [here's an additional non-animated picture](_URL_0_). Using the same principle you can go beyond 4D and do this for 5D, 6D, etc. The results get increasingly difficult to visualize both because our brains are not able to handle the images and because we can only use 2D images (flat screen of your computer or a sheet of paper) or possibly 3D toy models to represent the multi-dimensional objects. You can certainly imagine it's a difficult task to do. But what is this all good for? Why would anyone need a 4D, 5D, 6D or whatever-D object? This seems like a mathematical curiosity at best. However, there are many practical uses and I will explain them in the following with a simple example. Before, I kept mentioning how each dimension adds a measurable quantity to our objects. We commonly say that our world is 3D, because it has the measurable quantities of breadth, width and height. However, if you stop to think about it, there are a lot of other things you can measure: There's time, which is often called the "fourth dimension", but you can also measure more simple things like the amount of money you have, how many green apples you bought and how many red apples you bought. Each of these things you can assign a number to, can be thought of as a dimension in mathematics. Keep in mind that this concept of dimension is a bit different from the purely geometrical one, where each dimension corresponds to an object's size. This different take on dimensions is mathematically really useful if you're trying to track changes in several distinct things, or variables. For example, a farmer might be interested in how much food and water his cows consume, how much milk they produce, how much they have to poop, how much space they take up, how often they get ill and so on... in total, the farmer has to keep track of six variables (food, water, milk, poop, space, illness), he's dealing with six dimensions. Thanks to those crazy mathematicians that invented formulas for 6D objects, the farmer can apply the same formulas to the variables influencing his cows. This way he can find out how to best feed them so they do not get ill and produce the maximum amount of milk, while keeping the amount of poop as low as possible.

when you ignite your propane barbecue, why does the flame not travel down the hose and into the tank?

The propane needs oxygen to be able to burn (burning is just chemically combining with an oxidizer), and there's no oxygen in the hose. As long as the pressure is such that the propane is constantly pushed out, then oxygen can't get in, and the propane in the hose can't burn.

What are the possible evolutionary causes of missing baculum (penis bone) and penile spines in humans?

Sorry you're incorrect, pearly penile papules are not a "condition" they are 100% normal, and are considered a simple anatomical variation. Please do not mistake these as any kind of STD or a vestigial form of a penis spines as they are histologically very different (keratinized epithelial vs vascularized connective tissue) _URL_0_

Has there ever been a society where 2 very different languages coexisted together?

This is extremely common. Quechua and Spanish in Peru Guarani and Spanish in Paraguay English is a lingua franca through most of south eastern Papua New Guinea, where Oceanic languages are spoken. Hindi/English/local languages in India etc.

why do headlights at night seem to blind me while headlights in the day do not if their intensity stays the same?

Your pupils are larger at night as there's less ambient light. Bright headlights in that situation let in more light than you can handle.

how do supermarket trolleys get "stuck" to escalators and then suddenly work again once they've moved off?

Magnets is exactly right. The magnet holds the trolley to the escalator, and the grooves just help to keep the trolley centered so it can be pushed off at the end.

how can shows such as house of cards have differing writers and directors every few episodes, yet still remain consistent in tone and feel?

The producer for the series hires people with a similar sensibility and gives guidance so that they maintain a consistent tone.

Have there been studies documenting the effects of hallucinogens on people with blindness or other sensory deprivation? What did they find?

This is really complex. If I were you, I'd check out the book "Hallucinations" by Oliver Sacks, as he talks about this extensively. In short, people who become blind can have hallucinations after - this disease is called Charles Bonnet Syndrome. It generally believed that when the brain is deprived of visual stimuli and thus deprived of activity in visual areas, it makes its own activity, causing people who have developed blindness to sometimes experience visual hallucination. This is all I can really say about it without cracking out the book to get you specific details.

why can’t you donate menstural blood?

Well more or less because its basically uterus wallpaper not exactly just blood like you would find in your veins.

how do superchargers make cars go faster? or why?

Put simplistically, the power from an engine is made from the combustion of fuel and air. A supercharger compresses the incoming air, allowing more to enter the engine. More fuel is added to the engine via the fuel injectors, and the two combined combust to create more power than would have otherwise been made.

how do television ratings translate into monetary benefit for the stars of the show?

That's basically it. The amount actors are paid is based on the previous season's ratings/advertising. So usually the during the first season of the show, the actors aren't paid very much. The exception would be for actors who themselves carry aadvertising value and are assumed to bring more viewers to the show. Like Matthew McConaughey... they assume him just being in the show will bring more viewers, and thus more advertisers.

Are there any organic materials that harden over time or when exposed to the air?

An insect's exoskeleton is made of chitin, which hardens upon contact with the air. It doesn't continuously harden, it gets to a certain toughness then proceeds no farther. The problem with something continuously hardening over time is that as it hardens it will become brittle. Most organic materials require a certain amount of flexibility. A possible solution is to have the dragon's scales continuously grow over time, so that its armor gets thicker (and thus tougher) over time. The problem is that as the armour gets thicker the dragon gets heavier and movement (especially flying) become more difficult. If you're looking for a tough organic substance, the claws of a pistol shrimp and a mantis shrimp are incredibly tough. They can survive cavitation and can punch through aquarium glass. Their claws have a high percentage of calcium and are thicker.

Do astronauts shave in space or do they wait till they get back? Mostly they look clean shaven - so I guess yes. However, with everything in space about 16 times more complicated than back on the planet...I just wondered

Here is a [description from the Canadian Space Agency](_URL_0_).

Why did the Romans build on top of things?

The phenomenon you are noticing is called "stratigraphy", which is the idea that things are built on top of older things, and you can tell which things are older by figuring out the order in which each part was laid down. It's one of the most basic and essential parts of archaeology. Now, why did people build on top of older ruins? There are several reasons. First, when ancient people had a place they built on, and made a settlement or a city, it was because that place was a really good place to build a city. Take some of the major sites in the southern Levant for example, such as Tel Megiddo, which sits right on one of the only pathways through the Carmel mountain range, and is basically a gatekeeper between anyone coming from the south (such as Egypt) to the north (heading to Lebanon or Syria (aka the Phoenicians or the Arameans)). Or Tel Ashkelon, which was a major trading port between Gaza and Jaffa. When people have a good place to build, they want to stay there. It makes no sense to suddenly move a few miles if your water system is still there, and the trade routes are still there. The economy is much less movable than some dirt. So, why build on top instead of tearing everything down? The simple answer is it's easier. It is much easier to knock down a broken down building and level it off with dirt than it is to break up the pieces and take them away. This is way before any heavy machinery, there are no backhoes here. And sometimes buildings are built with big, heavy stones, and its so much easier to just cover it over rather than move it. Also, dirt tends to accumulate among settlements, just from people's waste and all the things they bring into their settlement, and the buildings are a wind trap for airborne sediment, so the dirt level is rising already, people just help it along a little bit sometimes. You are exactly right about the level of a city rising as time went on, and people built over older things over and over. At Tel Ashkelon, in one of the excavation areas, which was occupied for about 3500 years, you have at least 24 different major rebuilds (not counting minor ones where they just expand a building or add a few walls), all within about 8 meters of vertical accumulation. This method of sediment deposition results in a distinctive shape of the hill. Hills which are basically composed of cities built on top of broken cities and on and on have a special name. They are called *tels*. They often have a flattish top and slightly steeper sides, as you can see in [this picture of Tel Megiddo](_URL_0_) and [this picture of Kedesh, a site in Israel](_URL_1_). So basically it's really common in the eastern Mediterranean and most ancient societies, because once a settlement is founded, there are lots of good reasons to live there, and so people keep living there, and it's just easier to knock stuff down and build over it than it is to remove it all. Does this answer your question?

why can you bring extremely fire hazardous items as hand luggage on an airplane?

Fires are a threat that aircrews are trained to deal with and lie within their response capabilities. Anti-terrorism forces worry about things that could take down an airplane (fuselage penetrating explosives) or allow a plane to be highjacked and used for terrorism. Fires are neither.

Why does a small crack make a "strong" material so much weaker?

This happens because [stress concentration](_URL_0_) occurs around the crack. Even though the average stress throughout the material sample is only slightly higher, the localized stresses at the end(s) of the crack are much higher. The maximum stress around a crack is proportional to (a/b)^(1/2), where *a* is the length of the crack and *b* is the width. So, if the crack is very long and narrow (as many are), you can see that the stress concentration at the end of the crack will be very high, which will cause the material to fail and the crack to propagate further. This process repeats as long as the crack is still around. This formula for stress concentration can also be used to explain why "drilling cracks" is a common temporary solution--it increases the radius of the end of the crack, which has the effect of reducing the stress concentration.

How do we define irrational exponents?

* _URL_0_ You can also use the sub search function: * _URL_1_

Is the ANY evidence at all of Native Americans travelling to Europe before Columbus?

There's always room for discussion, but perhaps the section [Travel and contact across the Atlantic before Columbus](_URL_0_) in our FAQ will answer your inquiry.

what are the reasons behind the various sizes of books?

It depends on who the book is targeted at. Harry Potter for example, wide pages, big letters, lots of spacing, easy for a child to read. Then Game of Thrones, short pages, smaller font, closely spaced. Made to be read by adults. Also, the length of the book. HP books are wide but not a lot of pages. GoT has a lot of pages, so it's better to make small pages. (Wish I could word this better)

how do cereal makers decide which vitamins and minerals to fortify a certain cereal with?

The reason I'm asking is because I was looking at the back of random cereal boxes at the store, and thought it was weird how much of a huge spectrum of vitamins and minerals there are. They have very different choices in different cereals, even by the same makers! It even just varies greatly with kid cereals from the same company. Do they choose by flavor or the texture of the cereal or something? Also, why is this common anyway? I'm guessing for marketing to look like some of the kids cereals aren't junk food or something. Thanks!

How the South and North of Italy in 1861 were? Some say if it weren't for the south of Italy, the north would be still third world today. How much is it true?

The "Southern Question" is indeed one of the longstanding dilemmas of Italian Economic History. Research into this topic is not as florid as you might initially think: for much of Italy's unitary history the "Southern Question" was perceived as a principally political topic, and it's only in last ten or so years that the "Question" has received steady attention from a growing cadre of economic historians, especially from those who are themselves located in the universities of the Italian South. Paolo Malanima at the University of Catanzaro, Emanuele Felice at the University of Chieti, and Claudia Sunna at the University of the Salento, are just some of the economic historians whose recent books and papers have been well received by their academic peers both in Italy and abroad, igniting new interest in Italy's lopsided economic development. The present academic consensus is that at the time of unification, the North of Italy was slightly more economically developed than the South of Italy. However, the social and institutional apparatus in the north was better positioned to take advantage of imminent industrialization process that would take place after unity, quickly creating a perceptible gap in development between the two halves of the country. By the turn of the 20th century, a political discourse had already emerged around a "Southern Question" which has not existed at the time of unification (the terminology of "Question" itself seems to have been coined by the influential politician Giustino Fortunato, who served as member of parliament for Melfi between 1880 and 1900). Of course there is a lot of nuance tied to the study of historic inequality, especially in a late industrializer like Italy. Unfortunately, there are many difficulties tied to creating precisely assessments economic development in Italy immediately before and after unification. While scholars (notably Vera Negri-Zamagni at the University of Bologna) have attempted to quantify economic development by looking over what little data is available with a careful and critical eye, there are still many possible pitfalls: one of many examples is the fact that as late as 1881, southern women who practiced sewing and weaving at home were classified by local censors as “Textile Workers.” When census norms changed and no longer considered work done in the home as "Employment," this caused a precipitous increase in unemployed women to appear in data coming from the South, even though real economic activity hadn't changed much at all. One stand-in for institutional and social development that researchers have found good to work with is literacy and primary education. In this measure, the pre-unitary Southern Italian Kingdom suffers from a lack of public education policy, entirely reliant as it was on the clergy and their parochial schools. As a result, at the moment of unification in 1861 90% of southern Italians were illiterate, and only 20% of children were able or willing to enroll in primary education. This stands in stark contrast with Piedmont and Liguria, the most significant territories of the Kingdom of Piedmont-Sardinia (the polity which would go on to unify Italy) where in 1861 literacy stood at 53%, and, 93% children were enrolled in primary education thanks to universal education policies. The estimates (postulated by the aforementioned Negri-Zamagni in "*La situazione economica e sociale nel meridione negli anni dell’unificazione: Una rivisitazione*” published in 2013) certainly can have some issues, as in both north and south measures of literacy were inconsistent. However, it this disparity is corroborated by other indicators: in 1862 (immediately after unity) 6.1 letters per inhabitant were mailed in the northern region of Piedmont, while only 1.6 letters per inhabitant were mailed in the former territories of the Kingdom of Two Sicilies. The mailing of letters is also reflected in the disparity between professionalized industries in north and south, like banking and insurance, who would be making most use of postal correspondence. Between 1827 and 1848 (thus in the pre-unity period) of the 53 banks chartered all over Italy not one was founded in the Kingdom of the two Sicilies. The south would have to wait till 1850 for its only two commercial banks to be founded (the Bank of Naples and the Bank of Sicily). While we have no fair pre-unity estimates for insurance companies, in the post unity period (in 1865) of the 88 insurance companies registered in Italy only 21 were based in the South, against the 67 in the North. And beyond banking and insurance, in 1865 of the 208 joint-stock industrial corporations in existence in Italy, only 17 were registered in the South; a serious marker of lack of development in a country that was just then joining the industrial revolution (my source is, as above, Negri-Zamagni). So what stopped the South from developing the hallmarks of an industrial economy, like banks, insurers, and most critically industrial corporations? The consensus is attributable to the lack of legal or institutional framework favoring capital accumulation in the Kingdom of two Sicilies. Indeed, it would seem that the southern monarchy was itself disinterested in favoring industrial growth, preferring to award of letters patent to foreign investors for what few industrial endeavors might take place. Even things like military and naval procurement was outsourced. The railroad, hallmark of the industrial revolution, was only built to connect the King's summer palace to the King's winter palace. Cause and consequence of this lack of initiative was the southern moneyed classes' preference for investing in extensive agriculture, rather than industry. The attitude in the north, however, was much different. The Kingdom of Piedmont lived a precarious existence sandwiched between the Austrian and French Empires. A finely honed instinct for survival among its political class, in addition to an influx of political dissidents from the Austrian-held parts of Italy (as well as a few thinkers expelled from the South) fomenting political thought, led the Kingdom to do its best to imitate the great powers of Europe in industrial development. Policies weren't always successful or well thought out, but they were successful enough to turn the maritime city of Genoa into a center of naval construction, connecting Genoa to the capital of Turin via a railroad, and even develop plans for a future connection between Turin and Switzerland. In Austrian-held Italy too, a political and entrepreneurial class based in and around the city of Milan worked to imitate their peers in Austria, Bohemia, and Hungary, in order to foster economic development: milanese entrepreneurs financed railroads, canalization of waterways, and founded a series of technical and vocational schools (a far cry from the southern system, which as mentioned above relied on parochial schools). It is worth keeping in mind, though, that Italy at the time of unification was still a fundamentally agricultural economy. France, Great Britain, and parts of Austria were much more developed. The gap between Northern Italy and the industrialized regions of Europe would not close until the 1980s. But why did the gap close in the North and not in the South? The question is one of the many that Emanuele Felice tries to answer in his concise but ambitious, "*Ascesa e Declino*." The north was certainly helped by the presence of a great river, the Po, whose tributaries could be turned into canals to water farms and power mills, and which could be navigated by barges, creating a large unified marketplace even before the construction of the railroad. The south had no such hydrographic advantage. The north's cities were also geographically closer to the industrialized regions of Europe, and thus exchanging goods, materials, and ideas was much easier than in the South. The north would also benefit, in the long run, from the two world wars: Haphazard and hurried wartime planning meant that production of wartime materials was focused where there already was productive capacity, thus turning the north's marginal advantage into a much more substantial advantage. But Felice also identifies policy decisions taken in the post-war era as important factors. In fact, the gap between north and south seemed to be closing in the wake of the second world war, but would begin increasing again following the Italian response to the global economic slowdown of the 1970s: deliberate decisions were made to direct state-sponsored conglomerates as well as government procurement to favor the country's least developed regions. This created a paternalistic and clientelistic relationship between southern entrepreneurship and the government, with entrepreneurs quickly preferring to follow lucrative subcontracts offered by the state and state-sponsored entities, divesting from existing industries that had driven the south's budding economic growth up to that point. I'm very bad with conclusions, but that's the summary of the leading academic consensus. Feel free to offer any follow ups or additional questions you may have.

Why would space planes not be a suitable method of interplanetary travel in comparison to typical rocket designs?

Our main problem in space exploration is the cost of launching into orbit. It's in the order of several thousand US$ per kg. So, first of all, consider how much fuel you need to achieve orbit. [Here's a picture of a Space Shuttle on the launch pad](_URL_0_). Note how the huge fuel tank is larger than the spaceplane itself. Putting some numbers, it was a total mass of 2000 tons on the launch pad out of which only 80 tons made it to Low Earth Orbit (LEO). It didn't have enough fuel to reach another planet, the Moon or even just geosynchronous orbit - if you want to do that you'll have to increase the mass at liftoff by a significant factor. Then, when landing, the spaceplane was only able to land itself, at most it could be loaded with an extra 20 tons in its cargo bay. No way it could land a comparable fuel tank to take off again from a foreign planet. Consider also the difficulties of flying in a different atmosphere, or landing without a man-made runway. Second, in order to make them lighter and cheaper, spacecraft are usually designed specifically for their mission goals and for the environment they will have to operate in. The Space Shuttle was not able to support human life in missions longer than a few weeks (no significant recycling of life support resources like water or oxygen), was not able to protect astronauts from radiation in the long term, and would not have been able to work correctly in a harsher thermal environment. If you do design a spacecraft for a variety of environments or for goals other than the ones intended, in aerospace jargon this is called "overdesigned". Basically it means you're using more mass than you actually need. Making things unnecessarily heavy means making them unnecessarily expensive, i.e. wasting the space agency's money. If a company does this then it is unlikely to be chosen for further contracts with the same space agency in the future (but they are actually unlikely to do it because the design is reviewed and negotiated with the agency at all times). Both aspects would change if we ever develop a propulsion technology that makes access to space significantly cheaper, using only a small mass of fuel that can fit inside the spaceplane. But today this is not part of the foreseeable future.

John Adams wrote that the US constitution was, "made for a moral and religious people," and that it is, "wholly inadequate to the government of any other." What elements of the constitution did he believe were suited for a religious society but not an irreligious one?

It is interesting how many sites quote these particular lines, but provide no context, or even bother to cite the origin. Most of them do so with the obvious intent of saying that the US is a religious country, and has to be a religious country because John Adams said it had to be religious country. It's useful to look at it in context. It's from his [address to the Massachusetts Militia in October of 1798:](_URL_2_) > While our Country remains untainted with the Principles and manners, which are now producing desolation in so many Parts of the World: while the \[ USA \] continues Sincere and incapable of insidious and impious Policy: We shall have the Strongest Reason to rejoice in the local destination assigned Us by Providence. But should the People of America, once become capable of that deep .... simulation towards one another and towards foreign nations, which assumes the Language of Justice and moderation while it is practicing Iniquity and Extravagance; and displays in the most captivating manner the charming Pictures of Candour frankness & sincerity while it is rioting in rapine and Insolence: this Country will be the most miserable Habitation in the World. Because We have no Government armed with Power capable of contending with human Passions unbridled by morality and Religion. Avarice, Ambition ,Revenge or Galantry, would break the strongest Cords of our Constitution as a Whale goes through a Net. Our Constitution was made only for a moral and religious People. It is wholly inadequate to the government of any other It is comparatively easy these days to split off "moral" from "religious". But in this period ( and well into the 20th c.) to say someone was spiritually-guided carried an assumption they were morally-guided as well. Religion was thought to be the main impetus to virtue. Some philosophers like David Hume could argue against that, and show by example that the two did not have to be linked, but the notion of a moral atheist was pretty rare: most people would believe that the only thing that kept humans from doing terrible things was their fear and love of God. Here Adams is using the terms together to make an argument for the Constitution very common to the 1790's: that its success depended upon the active participation in the government by law-abiding honest people. But it also shows one concern that Adams had in particular. Many of the founders, like Madison and Jefferson, thought of Americans as being relatively equal, and content to be equal. Unlike them, Adams ( after the Revolution) thought that humans tended to strive for superiority, and that, even without a hereditary aristocracy in the US, there would arise an aristocratic elite and an unruly mob wishing to loot and supplant it. He was pretty comfortable with the idea of that elite class being a good force ( maybe here, more "armed with Power" ) perhaps even thought the US could have the equivalent of a House of Lords. He thought that the balancing of powers in the Constitution also provided some defense against the conflict, but he was always very uneasy about the danger of mob rule. In 1798, he would be quite aware of the French Revolution "producing desolation": that certainly would have put him in mind of the possibilities of a populace no longer moral and religious. & #x200B; John Adams : A Defense of the Constitutions of Government of the United States: [_URL_0_](_URL_1_)

Was there ever a black American mafia as structured as the Italian and Irish?

Absolutely, in many major (and minor) American cities, there were wings of what we would call the "Black Mafia." Typically unrelated but very powerful crime syndicates in the African-American parts of town. Phildelphia, Chicago, New York and Detroit each had their own families, syndicates, brothels, and gangs. I'll outline one of the more prominent groups that existed with The Harlem Mafia. ***The Harlem Mob*** One of the most famous figures that dominated the Harlem scene was Stephanie "Madame" St. Clair. A Creole Black Harlemite who ran several rackets and gangs across Harlem, owned the Black police force, and was known as "The Tiger of Marseille." When notorious gangster Dutch Schultz tried to edge in on the numbers games in Harlem, St. Clair reportedly said: “Ze God-damned Dutchman can keees my ass,” she hissed. “He zinks I’m some stupid nigga? I show him he zinks wrong!” St. Clair would use her enemy in Schultz to leverage favor with the Italian mobster Lucky Luciano, having him act as protection for the Harlem mob while only paying the Italians a pittance, insuring Black Mafia control of Harlem. Following (and working with) St. Clair comes probably the most famous black mobster in Ellsworth "Bumpy" Johnson, the Black Kingpin of Harlem. He was a Numbers Game operator, enforcer, drug dealer and Mob Boss who operated in Harlem from the 1930's to the 1960's. He became such a prestigious figure that he appeared in Jet Magazine [once](_URL_0_) after he left the hospital for being shot and [again](_URL_1_) when being arrested for selling heroin. It was under the control of St. Clair and Johnson that famous nightclubs like the Cotton Club were able to flourish in Harlem. **Sources** *Harlem Godfather: The Rap on My Husband, Ellsworth "Bumpy" Johnson* Mayme Johnson *The Cotton Club* James Haskins

What did the Egyptian and Syrian governments believe about Israel's nuclear weapons capabilities in the run up to the Yom Kippur War?

Oh, this is such a good question, I can't believe I let it languish for 25 days! Sorry for not procrastinating on my other work earlier so I could answer this; I mean that sincerely, I love this question :). From the first, I think it's important to mention that Egypt at the very least was aware that Israel had nuclear development, and that it also appeared to have overflown Israel's Dimona nuclear site multiple times even in the 1960s. For a fascinating read on how this might've played into the 1967 tensions before the Six Day War, [Avner Cohen, one of the experts on Israel's nuclear program](_URL_1_), wrote well about it. Another interesting read on that can be found [here, by Ariel Levité and Emily Landau](_URL_0_). At any rate, what was known by 1973 was, obviously, different from what was known in 1967. What the Arab states knew, we can only speculate on based on what's been publicly revealed. Secret information has remained secret, for obvious reasons, in both Israeli and Arab archives. However, the nuclear issue is such an open secret by now that we can definitely glean information of use. Following the end of the 1967 war, the Arab states now accepted Israel's conventional military edge. That may explain, to some extent, why they felt powerless to address what they knew was an existing nuclear program, and what many states knew was being developed. Egypt had, in the past, sought to use conventional war as a deterrent and threat to Israel, a sort of last resort in case Israel began to cross the nuclear threshold. They'd also wanted to use their own potential nuclear programs as a deterrent, but that was also out of the question; the war had not only destroyed Egypt militarily, but it was also now suffering an economic issue, and couldn't easily afford a nuclear program. There were no more threats of preventive war that really held water. The Arab states thus looked the other way on Israeli development, because they knew Israel's opacity would benefit them. They could do nothing about it, so better to ignore it than afford to look even weaker in the face of that development. That also allowed Israel to adopt its opacity position, using ambiguity in such a way as to ensure that the signals both sides sent to one another didn't lead to escalation neither wanted, but that the Egyptians in particularly really couldn't afford. The primary issue on Israel's nuclear program ceased to be Arab threats, and began to be American pressure instead. That is a story of its own, so I'll leave that one out. The important bit is this: by 1970, the nuclear program was largely known. The *New York Times* reported as much in July 1970, revealing that the US government now assumed that Israel either had a nuclear weapon, or could assemble one quickly and easily if needed. The Arab states *knew* in 1973 that Israel possessed nuclear weapons, and they chose to attack anyways. However, that's not to say it had no impact on their decisions. Instead, it appeared to have led to them adopting constrained, limited methods and objectives, as raised by Cohen in *Israel and the Bomb*. At the same time, Egypt miscalculated what Israel would react with to its attack in 1973. Yet Yair Evron in *Israel's Nuclear Dilemma* argues the exact opposite; that Egypt effectively ignored the nuclear issue in 1973, and was limited in its objectives because of its conventional limitations, and that it didn't take nuclear issues into account because it believed their use would not occur. There's also an argument that their actions were consistent with any non-nuclear adversary fighting a war with a nuclear power, and he references the way that China and the Soviet Union acted in relation to the United States before they got their nuclear weapons. At any rate, I've seen very few people argue that the Egyptians were unaware of the Israeli capability. Abraham Rabinovich, in *The Yom Kippur War*, mentions quite clearly that Egypt was "aware of Israel's nuclear potential, but [Egypt's] limited operational goals in Sinai did not threaten Israel's borders and therefore were not seen as risking a doomsday response". It's also important to know that while Egypt and Syria may have seen the public reports, we have no idea what Syria did or did not know beyond that, and whether they had information shared with them by Egypt, at least as far as I've seen. Nevertheless, it's commonly believed that they knew Israel had a nuclear weapon. And it also seems unrealistic that the coordination prior to the war would've left out that Syria would be facing a nuclear power, while Egypt was aware, even if the public reports weren't enough. However, their view of the way to interact knowing that is less understood. How they viewed their war aims was probably shaped by Israel's nuclear policy, but I've seen little knowledge about what that effect was. Here's the funny thing, and where I'll just go a bit beyond your question: the limited aims, and the way Egypt (and probably Syria) perceived those aims as being a good way to avoid nuclear war, still gave rise to the infamous alleged arming of Israel's nuclear arsenal, as recounted popularly by Seymour Hersh and subsequently investigated/discussed many times over. However, Rabinovich points to many sources saying that the decision to deploy the weapons was greatly overblown. Yuval Ne'eman, a nuclear physicist and former intelligence officer, is quoted saying it would be normal to advance preparedness any time a war occurred, but that there was no deployment for possible use, as was reported. Apparently it was considered during a discussion by generals, but it was also debated quite fiercely, with no resolution. However, it apparently was never debated by the Israeli Cabinet, according to what Rabinovich (a fairly well-respected journalist) called "reliable Israeli sources". Avner Cohen has a different take, citing a source at the war cabinet's meeting on October 9 who apparently claimed that Israel's Defense Minister Moshe Dayan had discussed a nuclear demonstration when the war seemed at its worst. The Israeli atomic head was there and ready to discuss, but other ministers chimed in and it ended there. There are plenty of other rumors, and claims, but this seems like a potential one. Cohen also claims that nuclear alerts were declared, twice in the first week of the war and once on October 17, when Soviet SCUD missiles were put on alert in Egypt. The belief is that the missiles were fueled and mobilized, something that requires only the Prime Minister and Defense Minister to agree (the cabinet doesn't have to make a decision, according to Cohen, just those two), but that the Prime Minister never went further than that. Continued in a response to my own comment.

About innovations and disruptions in the past 100 years I feel that there was a true peak of innovations in the early 20th century (1900- 1930). Is there any proof in academic literature of this as well as explanations why there have been so many innovations during that time? Or am I just biased?

The innovations pioneered around that period were arguably more broadly and popularly *impactful* than other periods, but that doesn't mean they were more numerous. The changes in that era were profound - a way of life that had continued fairly unchanged for many centuries was fundamentally altered in developed nations. Previously, one would travel by horse or foot, burn candles for light, communicate verbally or by writing, and poop in a hole. Suddenly, people had cars and trains, electric light and power, radio, and indoor plumbing. (Some of these were older inventions made popular and affordable by industrialization; this too is part of the innovations.) While innovation has continued, and arguably increased, the "low hanging fruit" of changing human lifestyles has pretty much been picked. Cell phones and Internet are wonderful, but they are as much *improvements* of the concept of radio as they are inherently revolutionary. A smart car is vastly more complicated than a Model T, but is still a car. Microwaves are neat, but radiating my hot dogs instead of boiling them is hardly earth-shaking. Moon travel and nuclear weapons don't really effect everyday life the way a light bulb does. I'd argue you may have a bias based on the commonplace impact of earlier industrial innovations, the nature of which arguably made them seem more numerous. Material science or computer coding aren't as apparent or basic of changes as previously.

How do companies like Jack Daniels that make a product that needs to be aged for years predict how much product they will need in the future?

Whiskey sells on such a large scale, and the market changes so little. A large chunk of big name liquors get sold directly to bars, whose annual usage has very distinct trends. This cuts a huge chunk of unknown out of their sales figures. And while more and more people are turning 21, people in their early 20s are not the primary consumers of whiskey. So the buying habits of Jack Daniels customers shouldn't be difficult to predict four years in advance. The market overall doesn't change much.

How far can a raindrop travel horizontally begore hitting the ground?

I don't see anything besides wind speeds and the altitude of the cloud coming into play. Best bet would probably be to look up the most windy hurricane and find out how far away from the edge of its clouds people felt the rain.

What would an observer in the farthest galaxy see?

The universe is believed to be infinite and isotropic. Thus there is no "leading edge" of the big bang. The big bang occurred simultaneously at every point in the universe, and was an expansion *of* space, not an explosion *in* space. Given all that, someone at the farthest galaxy that we can see would see the same type of things that we ourselves see, including our galaxy at it appeared billions of years ago, as well as galaxies that are too far away for their light to have reached us.

Why is mercury-vapor used instead of non-harmful noble gases in lamps?

**Short answer:** mercury just happens to have atomic characteristics that make it useful for producing visible light at high efficiency, and it is superior to other elements to the point that we use it despite the possible dangers. **More details:** in a [gas discharge lamp](_URL_2_), you pass electrical current through an ionized gas (plasma). This excites electrons in the plasma atoms to a higher energy state, and when they fall back down to a lower energy state they give off photons of light. Different atoms have different energy states for their electrons, and as such produce photons of various energies characteristic to the type of atom. Mercury happens to produce intense ultraviolet light (along with some visible light), and the UV light can be converted into other colors of light by applying a fluorescent coating. The combination produces visible light with good efficiency at reasonable power levels. As an example of other technology, [xenon arc lamps](_URL_4_) are also used, and (at high power levels) can produce very bright light that is actually a closer approximation of natural sunlight than fluorescent lamps. However, they are less efficient. [Metal halide lamps](_URL_1_) use mercury vapor plus metal halide vapor to add in other spectral lines. They are effectively a combination mercury-vapor and sodium-vapor bulb, as the most common metal halide is sodium iodide. Note that these two are both "high-intensity discharge" lamps, with an electrical arc running between electrodes inside the lamp. They tend to operate at higher power levels, making them less useful for residential lighting. The metal halide lamps also have to (literally) warm up to their full light output, as the metal halide takes some time to heat up and vaporize - not good for residential lighting where they might be turned off and on regularly. Some of them actually cannot be re-lit after being turned off (intentionally or due to interruption of power) without being allowed to cool down for several minutes first. Metal halide lamps have similar efficiency to fluorescent lamps, and are growing more common in large-scale lighting applications where their drawbacks are less relevant and their high power, high [color rendering index](_URL_0_), and high efficiency are useful. [Low-pressure sodium vapor lamps](_URL_3_) are some of the most efficient light sources in existence and use no mercury, but the nearly monochromatic yellow light they produce almost completely destroys the ability to recognize colors, resulting in them being considered unacceptable for most indoor lighting applications.

Exactly where was FDR when he found out about Pearl Harbor?

At about 2pm ET the President was in the Yellow Oval Room on the second floor of the White House with friend and aide Harry Hopkins when Secretary of the Navy Frank Knox called and first told him if the reports from Pearl. He was called again a few minutes later by Admiral Stark the Chief of Naval Operations to confirm and expand the reports. Final confirmation came then when Hawaii Governor John Poindexter was put through to the President and the second wave of the attack descended during the conversation. FDR used the room as a personal study and private space mostly. He kept naval prints and model ships there along with his stamp collection, but would also work out of it. Earlier in the day he had sent regrets to Mrs Roosevelt that he could not attend a reception downstairs, though he would later try to use the attack as his reason for missing out vs just wanting some free time. Through the rest of the day he would stay there while his senior military leader's assembled, then in the evening address leader's from Congress, and his full Cabinet. All the while his secretaries had set themselves up in the adjoining rooms with phones and typewriters to deliver copies of the latest news from the Pacific. It was also here late in the evening that he would draft the speech he would give to Congress and also spoke to Prime Minister Churchill briefly to confirm that both nation's had been attacked by Japan and reaffirm their support for each other.

What happens if I get hit by a gamma ray?

You *are* getting hit by gamma rays all the time.

Say I am an author around the 1850's in the USA, and I just wrote a book, and I want it published. How would I go about that? Were there any distinguished publishing companies? Do I just make a lot of copies and distribute them in book stores?

There was a fairly flourishing US publishing industry by the 1850s. For example, Melville published with Harper and Brothers (which is is extant as HarperCollins), Poe with Putnam (also still extant as an imprint of Penguin), Hawthorne and Thoreau with Ticknor and Fields, Emerson with Philips, Samson. Source: William Charvat, *Literary Publishing in America, 1790-1850*. U of Massachusetts, 1993

Do bacteria exhibit a noticeable daily cycle in how they act and react?

Yes even bacteria can exhibit [circadian rhythms](_URL_0_) [Here](_URL_1_) is an example that is especially intriguing. The Viking Mars lander of 1976 tested labeled elements on Mars soils samples. They found the soil "consumed" the elements and detection of exactly the same (labeled) elements in the exhaust gas was proof of some sort of consumption/exhalation like an organism. However, because organic compounds were not detected in the samples, it is assumed by most researchers that the reaction was purely chemical and not biological. Miller and others have found evidence of circadian rhythms in the Viking data. If there is strong statistical support that the rhythm is temperature independent, then this is considered evidence toward some form of bacteria-like life.

how can dust damage electrical components?

[dust corrosion](_URL_0_) Dust contains all kinds of different elements, including some salts. The accumulation of these minerals over time paired with humidity, creates a salty solution, which then does what a salty solution does and eats into the material. I knew about this immediately because I work with structural fasteners, the kind that hold bridges and ships and buildings together. In storage they’re required to be covered to protect them from dust for this very reason. The dust can diminish any plating on the fasteners through the same process. Edit: added context Edit 2: added a related story

At what point would an outside observer have begun to make a distinction between Judaism and Christianity?

Not to put off any further answers or follow-up questions, but [this healthy discussion](_URL_0_) may be of help to you.

asian men wearing a western suit is acceptable, but why is it weird for a white guy to wear a kimono?

Because you are more used to seeing an Asian guy wearing a suit then a white guy wearing a kimono.

Why did the Dutch golden age end?

It's no really a case of decline but more a case of being surpassed in economic growth. This had a number of reasons: - Mercantilism/Colbertisme (other country's protecting their own trade) Example: Act of Navigation (1651) Banned foreign ships from trading in English ports. - high wages/ low productivity - Costly wars and disastrous wars. In 1672 an alliance of France, England, Sweden, Munster and Cologne Invaded the Netherlands and almost conquered it. This year is dubbed rampjaar ("disaster year") in Dutch. - Political Corruptness/Laziness the Netherlands where a republic and governed by a group of people called 'regenten' they where members of rich and influenced families, the most important regent was the *raadpensionaris van het gewest Holland* of *Landsadvocaat* the most important military role was *de Stadhouder* *de facto* was this a hereditary position hold by a member of the House of Orange. There was always a power struggle between the *Staatsgezinden* ( people who supported the Landsadvocaat ) and the *Prinsgezinden* ( people who supported the Stadhouders ) in times of peace and prosperity the *landsadvocaat* held the most power, between 1650 and 1672 there was no *stadhouders*. when in 1672 the french invaded the people blamed the regents for the state of the army and demanded a *stadhouder*. William III was made *stadhouder* and defended the republic. William had ambitions to become king! and in 1689 he became king of England, this meant safety for the Nederlands but the Bill of Rights prevented that William revoked bills like The Acts of Navigation. But it also meant that The Netherlands needed support England in some large wars, with peace deals that clearly favored British interests. (I'am looking a you Peace of Utrecht (1713)) In the same period ( early to late 18th centenary) the ruling class became corrupted and lazy they where more busy protecting their interests than protection the Dutch interest, they where becoming also more of a aristocracy/Plutocracy. They where appointing important jobs to each other, it was increasingly harder to join their class. - Political stability in the rest of Europe One of the most important factors in the decline of the republic is the growth of other countries. The Netherlands is a small country ( DUH ) and can't produce the same amount of goods than the economic power house France, the same is with manpower and military strength. The Dutch Republic most successful years where in the period that England, France and The Holy Roman Empire where weak. England had to deal with their civil wars (1639-1651) and the political aftermath. From 1688 there was a fast economic growth. France became a powerhouse under the rule of Louis XIV (1643-1715) he gave France the largest army in the world, this forced the Dutch to invest in their army what raided the tax burden in the Netherlands. between 1618-1648 their was the 30 year war in the HRE which devastated much of what is now Germany. The Netherlands where involved in this war, but the war didn't affect the Netherlands that much. After the war the HRE could rebuild them self. **TL;DR: The rest of Europe gets their shit together and simply out growth the Dutch. While the Dutch lost their edge they didn't had an answer**

why do avoiding left hand turns save gas?

If you have thousands of trucks, avoiding the time spent waiting to make left turns across traffic can add up, especially if your planning routes with dozens of stupid. In your personal life, where you only have two or three destinations, your never notice the difference or even travel further.

how likely is it to survive a headshot?

There are notable cases of people surviving a bullet that actually enters the skull and penetrates the brain. Malala Yousafzai, Gabrielle Giffords, and although it's not a bullet, you have to remember Phineas Gage, who survive a steel bar through the head. So yes, it's survivable, although the degree of deficits you have is often a matter of where it penetrates, and how young you are. More often though, a headshot is survivable because the bullet doesn't penetrate the skull and track through the brain. *Most* of the time that you get a bullet in your brain, you're not going to live, or live well. Most of the times that a bullet hits an unarmored head, it's going to kill you. Variables to consider in all of this are: Caliber of the bullet, velocity of the bullet when it hits (was it a long rifle at a 100 yards, or a 9mm pistol at 100 yards?), and the angle of the impact. That last only really matters if the bullet is relatively light, slow, and/or in the terminal portion of its flight. The thing is, the head is a small target, and it moves a lot relatively to the body; it's quite hard to hit on a human target without training, and a good rifle... or close range.

How dangerous was it for World Leaders to meet during WW1 & 2?

So the most spectacular example of this going terribly comes in June of 1916. Field Marshall the Lord Kitchener of Khartoum, who was serving as Secretary State for War was traveling to Russia in order to participate in negotiations and planning in person with the distressed Czar's government. He planned to take a RN cruiser up around Scandinavia to Arkhangelsk. He arrived in Scapa Flow in the Orkney's, which was the home base of the Grand Fleet. After meeting with Admiral Jellicoe aboard the Iron Duke he transferred to the cruiser HMS Hampshire. Owing to a terrible gale her 2 escort destroyers were sent back, the idea being ti was unsafe for them and U-Boats were unlikely to be a threat. Unfortunately about a week before, in the run up to Jutland, U-75 had put down a minefield and she struck one of these. Nearly all of her 700 passengers and crew were lost in the incident.

how many appliances can i plug into a single socket (using series of extension chords) without 'something going wrong'?

> I have a single socket in my room, and I use a series of extension chords to run a few ~~high~~low-power appliances such as a laptop, monitor, PS3, lampshades, speakers, LEDs etc. Fixed that for you Everything you listed consumes 200W or less. The laptop is probably around 30W while the monitors may be closer to 50W A standard US outlet/breaker can support up to 1800 W of power(15A). If you load it up to that level or beyond you run the risk of the breaker tripping and turning off all your connected devices. Based on your loads, you're probably drawing less than 500W on a regular basis(i doubt you have everything at max power at the same time) Don't add a toaster or hairdryer to the mix and you'll be good

why is it that when driving in cruise control, going uphill feels like the car is going much faster when in reality it’s maintaining speed?

When the car is in cruise control it is monitoring and attempting, as you said, to maintain the speed it was set to. When you go up hill the car faces more resistance as it has to work against gravity more, so when in cruise control this causes the car to slow down, the car notices this and then attempts to accelerate, like if you pushed down on the gas, to maintain the speed. You are likely hearing the engine rev up which we usually associate with 'going fast,' but the car is just maintaining.

Why is Carbon and Water so fundamentally necessary for life? Couldn't an extraterrestrial lifeform be based on, let's say, silicium?

Water is important because it is a potent solvent and is liquid in a temperature range that is conducive to organic chemical reactions. Carbon is important because it is fairly inert once in molecules so you can form many long complex molecules off the same more or less inert back bone. this has to do with the electron structure of carbon, so a chemist can expand on the specialness of carbon. As for silicon based life, the short answer is no. the waste produce for most life is CO2 via cellular respiration this is a gas that can be easily dissolved into water. for silicon the waste product would be SO2 or sand/quartz and is very inert and highly stable. So the SO2 lockes down resources (like oxygene) much more than CO2 and as a solid is much more difficult to move around. the long answer for silicon is maybe, but it would be at very high temperatures and be a bio chemistry very different, even on an mechanical basis (resembling more inorganic chemistry), than what we have on earth.

When the slaves (in America) were set free, did they take the name of their master?

According to Eric Arnesen in *The Black Worker: Race, Labor, and Civil Rights since Emancipation* and Richard Valelly in *The Two Reconstructions: the Struggle for Black Enfranchisement*, slaves so despised their masters that one of the first things they did as freemen was change given names. Instead, they adopted names taken from places, trades, and even African relatives. Keeping the master's name was considered a last resort as a means to escape the rampant violence visited on newly freed blacks.

why do car batteries only need to be charged when fully dead?

They are actually charged every time you drive. This happens with a machine called an alternator. When your car engine is running, it also turns a little electrical generator that helps keep the car battery charged.

is there truly any way to get over non-seasonal allergies?

Immunotherapy is the process of getting micro doses of what causes allergies in the form of shots. Slowly over time your body builds up antibodies and you no longer have reactions to the allergens. At the clinic near me the process takes about 3 years.