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If you could suggest a single book for someone who wants to learn about the history of the US and US foreign policy what would it be? | [From Colony to Superpower](_URL_0_) by George Herring is pretty hard to beat for a once over of US Foreign Relations. | [
"Foreign Relations of the United States (FRUS) is a book series published by the Office of the Historian in the United States Department of State. The series presents the official documentary historical record of major U.S. foreign policy decisions and significant diplomatic activity. The series began in 1861 and n... |
how do powerstrips stop electric surges? | First, a power strip doesn't stop an electric surge at all. A surge protector does. A power strip is simply adding extra outlets, a circuit breaker, and possibly more reach depending on the length of the cord.
Second, the reset switch (circuit breaker) on a power strip or surge protector doesn't do anything when there is excess current coming in. It's there to protect from trying to draw too much power. Home electrical outlets are typically rated for 15A. So are most power strips/surge protectors. If you try to pull more power than that (i.e. plug in 6 crock pots at once or something like that), the circuit breaker will trip.
The way a surge protector works depends on how it's built. Typical surge protectors today use an MOV (metal oxide varistor) to absorb the excess energy from the surge. The joule rating on a surge protector determines how much energy the MOV(s) can absorb before reaching it's failure state. Some surge protectors also have a thermal fuse which disconnects one of the lines once it gets too hot.
Whether it stops working or not depends on the surge protector you buy. Some have automatic shutdown, which means that the outlets will stop working altogether once the surge protector reaches end-of-life (it's protection capacity is all used up). Others will continue to function and provide power to the outlets, with no protection available usually noted by a "protected" indicator light of some kind. In those, once the light goes off, your devices are no longer protected even if they still work. | [
"A power take-off or power takeoff (PTO) is any of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machines.\n",
"In addition, if overhead electrical power is fed from a trolley pole, the direction of t... |
how is it legal for a parent to smack their child? | Children are not extended the full rights of adults as a necessity for their parents to protect them. A child might be restricted from leaving the house after a certain time, while for an adult that would be false imprisonment. The dividing line between appropriate physical contact in a child's upbringing is a judgment call that those declarations of rights do not address. | [
"In December 2013, in an interview with \"The Independent\" newspaper, Atkinson made clear her personal view that parental smacking of their children should be made illegal. The response by the government was that they had no wish to criminalise parents for issuing a mild smack, while the NSPCC welcomed the commiss... |
why can a computer load a website in about a second but the same website on cell phone takes much longer to load? | Connected to wi fi? 3g? 4g?
What's the age of the phone and the age of the computer? Is your computer a wired connection? How many applications are open on your phone? | [
"Mobile phone users can access and use the same web sites on their wireless handsets that they visit using personal computers. Full web pages load in seconds due to compression and in-network processing of content by the server.\n",
"The first proposed interval between successive pageloads was 60 seconds. However... |
What was the star sized light I saw moving quickly across the night sky? | The international space station is often as bright as the brightest stars in the night sky. It takes approximately 2 minutes to cross the sky above you, depending on your field of view of course. | [
"Some flashes of lambent light, much like the \"aurora borealis\", were first observed on the northern part of the heavens, which were soon perceived to proceed from a roundish luminous body, whose apparent diameter equaled half that of the moon, and almost stationary in the same point of the heavens [...] This bal... |
why do do people cap their fps? isn't more frames = better? | From a brief google search it would seem there are many factors.
Game stability - stable fps is sometimes better than constant oscillation
Heat and other stresses on video cards
Power consumption
Reducing stuttering and screen tearing without using v sync
> Screen refresh rate x 2 + 1. So your 60hz will need a 121 fps cap.
(I don't know what this ones all about but iv'e seen it a lot)
For multiplayer as well it helps with server synchronisation
Essentially more isn't better, better is better. Quality over quantity and your monitor can only output so much anyway. | [
"Because both film speeds have been used in 25-fps regions, viewers can face confusion about the true speed of video and audio, and the pitch of voices, sound effects, and musical performances, in television films from those regions. For example, they may wonder whether the Jeremy Brett series of Sherlock Holmes te... |
with the volume of dyed fluids i consume, why is my urine only on the yellow -- > clear spectrum? i know the kidney is our organic filtration system but.... where does all the dye go? my fecal deposits are not tye-dye. | Most likely, the dyes break down in your stomach or upper intestine. Most dyes aren't particularly stable molecules, and your digestive tract is designed to break things down. | [
"Pigments excreted in urine are partially absorbed by urate sediments (\" sedimentum latrerium \"), which consists of cell debris and sedimented urinary components formed when the acidified urine is stored below room temperature. These urate sediments looks reddish or pink due to the presence of a main pigment firs... |
Are there any first hand accounts of the British soldiers' journey back to England after the Revolutionary War? | There are very few accounts written by common British soldiers of the American Revolution, and those few that exist are very brief about the trips across the Atlantic. Most are fairly bland accounts that amount to little more than simply stating that the ocean was crossed. Don Hagist has edited a definitive collection of primary source accounts by common British soldiers in his *British Soldiers, American War.*
You'll find better primary source accounts from the officers. I can't recall off-hand any specific sources that devote time specifically to the trip back to England. I would check the Journal of Lieutenant Enys and *John Peebles American War.*
EDIT: Almost forgot, check Thomas Anburey's *Travels in the Interior Parts of America* as well. He was one of the most prolific writers among British officers. | [
"In April 1776, on his way to New York City from Boston after his victory in the Siege of Boston, General George Washington camped in the town of Dudley with the Continental Army along what is now a portion of Route 31 near the Connecticut border. During the trip, it is rumored that a \"large cache\" of captured an... |
why do we have to choose between two presidents? why can't we vote for any president who runs? [us] | You could theoretically vote for any of the various presidential candidates who run. Just that the first past the post voting system used by the US punishes you severely for doing so.
For a good example of this, see the 2000 US presidential election in Florida. Many of the more liberal voters chose to vote for Nader instead of Gore. Now they would have most wanted Nader to win, but their next pick would probably be for Gore and they would never have voted for Bush. Sadly because only the highest number of votes are counted, they voted for Nader and not for Gore and split the vote. Thus Bush won, despite the fact that the combined vote for Nader and Gore would have beat Bush. This is a big problem for most elections, one that has an already formulated [solution](_URL_0_), but no political drive to actually implement.
TL:DR you can vote, but it effectively doesn't count. | [
"In the United States, the President is \"indirectly\" elected by the Electoral College made up of electors chosen by voters in the presidential election. In most states of the United States, each elector is committed to voting for a specified candidate determined by the popular vote in each state, so that the peop... |
Why did Stalin not fully support Mao in the Chinese Civil War? | It was mostly putting pragmatism above ideological goals. Partly, he didn't think Mao would win, and partly, he valued his relations with Chiang Kai-Shek as a buffer between Russia and Japan more than he valued his ideological "allies" in China. Stalin only decided to help Mao when it became clear he'd win.
This kinda lines up with Stalin's doctrine of "socialism in one country". Strengthen Russia through whatever means necessary, don't worry about revolution in the rest of the world. | [
"Stalin privately underestimated the Chinese Communists and their ability to win a civil war, instead encouraging them to make peace with the KMT. Stalin was worried that Mao would become an independent rival force in world communism, preferring a divided China with Mao subordinate to the KMT.\n",
"Westad says th... |
why doesn't chicken, beef, or any other processed meat go through rigor mortis when being prepared at a factory or even in the days afterwards? | Hate to break it to you, but they do.
Rigor mortis, depending on conditions (animal health, size, temperature, etc) takes 2-24 hours typically. In processed meat, it's already in a package by then. Sometimes, the process is allowed to complete, as it can actually result in more tender meat.
When it comes to big animals, like cows, controlled temperature and electrical stimulation (contracting/relaxing the muscles so they don't lock up) can be used to avoid or control it. | [
"Rigor mortis is very important in meat technology. The onset of rigor mortis and its resolution partially determine the tenderness of meat. If the post-slaughter meat is immediately chilled to 15 °C (59 °F), a phenomenon known as cold shortening occurs, whereby the muscle sarcomeres shrink to a third of their orig... |
Sound waves have never completely made sense to me. Specifically what makes two different sources playing the same note sound different? | I believe what you're talking about is called timbre. Its the result of varying harmonic resonances. A piano playing one note vs. A violin playing the same note sound different because the second and third order harmonics have different amplitudes bases on materials, structure of instrument, etc. I'm sure there is a much better explanation out there. I read about it in a book once. I don't have any degrees in music or anything. | [
"If two sounds of two different frequencies are played at the same time, two separate sounds can often be heard rather than a combination tone. The ability to hear frequencies separately is known as \"frequency resolution\" or \"frequency selectivity\". When signals are perceived as a combination tone, they are sai... |
Looking for information about Carthage and the Punic wars for research into a screenplay. | What would you like to know more about?
Here's some global info for you right now:
**TLDR: The Carthaginians left behind tons of stuff. We don't know where it is. Ancient written records are thankfully available. Small caveat, absolutely none of these people like the Carthaginians. There isn't enough salt in the world to make anything more then educated guesses. We roughly know what happened. When it could have happened and roughly where it happened**.
The bulk of our knowledge of the Carthaginians comes from ancient written records combined with limited archaeology. Of the city of Carthage itself very little remains and the Carthaginians weren't the cohesive Empirebuilders the Romans were. They greatly preferred a sublter touch, leaving local custom and powerstructures in place. They simply assumed soevereignity over the locals by carefully webbing them in to their trade networks. Soon the local elites realized the benefits of offering their fielty to the Carthaginians whilst retaining firm control of their own sphere's of influences.
This means that Carthaginian State ( They went through the same strongman/king > republic shift as the Romans. They main difference being that power being consolidated in a few hands only started happening in Rome closer to the end of their republic ) only routinely sponsored the funding of outposts and with great exception the founding of cities abroad. Individual commaders in recently "aquired" provinces taking advantage of this construct their own cities to control their territories easier. Very few locations of these cities remain unfortunately.
For instance New Carthage is somewhere on the eastern coast of Spain. This could be all the way in up Cataluniya or much lower near Valencia. We simply don't know, ancient written works fail us here and without their guidance archaeologists cannot confirm/add anything of much note.
However Carthaginian presence is notable all throughout the med. , from Sicily to Sardinia. From North Africa to Spain, little inscriptions of this (_URL_0_) pop up. The Tanit symbol, a female goddess-aspect (pene Baal) of their supreme god Ba'al Hammon. She was a war goddess for quite a few soutern med. cultures. Presumably used as a symbol to ensure fertility.
So now we know why we know so very little of the exactly geography of the Carthaginian network we have to rely more on the acient written records then other cultures whose own independant work was allowed to survive.
This is why is /love/ Carthage. From early on the Roman Republic there was an inexplicable fascination the Romans had with the Carthaginians. Even when Syrace was still on even footing with Carthage before her Queen of the Med. days. Carthaginians were regarded as strange people. Not quite Eastern. Not quite Western, but entirely Mediterranean nonetheless. The paradox amused the Greeks for they saw a fellow Polis determining their own future. It infuriated the Romans to no end to see the never ending ships that carried North Africas immense agricultural treasures (Oil, various produce and **WINE. YES WINE. THEY SOLD WINE TO THE GREEKS. SORRY FOR THE CAPS BUT OMG. THEY WROTE IN PUNIC ON THE AMPHORAS WHICH HELD THE WINE BUT USED GREEK LETTERS TO DO SO**. Greek wine was one of the finest of its day and in essense the Carthaginians stole the brand-name and claimed this faux-elite wine. Carthaginian wine was being drunk in Athens. Damn.) and hauling back gold and whatever supplies they needed that time of year.
This makes Greek sources slightly more palatable to read if you have any sort of interest in Carthage. Roman sources while initially reading almost neutral go through an interesting process. From the early days of the Republic the closer we get to the Punic Wars the harsher the language yet it still remains fair. Yes the Carthaginians are sneaky but their are succesful. Yes they are treacherous yet they have long term allies.
During the after the three Punic wars the image tearing and building begins. The memory of Carthage is still in everyones mind but now they are still sneaky, treacherous and now losers. The Greeks now join in with the Carthage bashing. After the memory of the Romans own behaviour (breaking agreements/forcing diplomatic incidents etc) leading up to the third Punic war falls into the fogs of time the true denegration can start. Plutarch says in 146BC:
" the character of the Carthaginian people … is bitter, sullen, subservient to their magistrates, harsh to their subjects, most abject when afraid, most savage when enraged, stubborn in adhering to its decisions, disagreeable and hard in its attitude towards playfulness and urbanity."
He contrasts them with the tolerant and lighthearted Athenians of old, naturally ignoring Athenian actions like the savagery at Melos, their judicial murder of Socrates, and their fawning over successive Hellenistic monarchs.
The ancient written records mostly used in rapid succession: Shamelessly copied this from Dexter Hoyos (Library of Congress Cataloging in Publication Data Hoyos, B. D. (B. Dexter), 1944- The Carthaginians / Dexter Hoyos. )
**Appian: an Alexandrian Greek and imperial bureaucrat of the later 2nd Century ad; wrote a history of Rome’s wars down to Julius Caesar’s time, treating each region in a separate book (that is, book-roll). His book Libyca narrates Rome’s campaigns in Africa against Carthage; Iberica, all their wars in Spain; Hannibalica, the campaigns of Hannibal in Italy. Some books are only partly preserved. Appian is very dependent on earlier histories; his chosen sources for the Punic Wars were often imaginative. His own composition methods, too, left him open to mistakes (sometimes silly ones). Even so, his histories of these confl icts offer useful information, above all on the Third Punic War where he mainly though not exclusively relies on Polybius.
**Cassius Dio**: a Roman senator and consul who lived from about ad 163 to after 220, Bithynian by birth; of his Roman History in eighty books from Rome’s foundation to his own times only some books survive in full, as do Byzantine excerpts from his earlier books and a virtual précis by the Byzantine John Zonaras down to 146 bc, as well as for some later periods. Dio is an intelligent writer, focused on Rome but prepared to be fair to other sides, and important too because he seems to have consulted older Roman sources (of the 2nd–1st Centuries bc) along with Greek authors.
Diodorus: a Sicilian of the later 1st Century bc; author of a Library of History in forty books, which he describes as a compressed world history taken from respected Greek predecessors. He seems to have compressed one at a time for lengthy stretches, though in places adding items from another source. This method can produce an uneven narrative, but Diodorus is still the main source for Greek Sicily’s history and its dealings with Carthage, as well as an important one for Greece and the eastern Mediterranean. His sources for Carthage’s wars in Sicily included Ephorus (4th Century) and Timaeus (early 3rd Century); on the Punic Wars he used Polybius. Of the original forty books, only 1–5 and 11–20 are now complete; excerpts, some long, others short, survive in Byzantine compilations.
**Justin**: a Roman writer of late but unknown date (between the 2nd and 4th Centuries) who made a précis of the forty-four-book world history by Pompeius Trogus, a Roman from Gaul of Augustus’ time. The Philippic Histories avoid a detailed account of Rome and focus on the rest of the world from the Assyrians onwards, with short but notable treatments of Carthage’s foundation-story and history from the 6th to the early 3rd Centuries. Trogus’ sources are unnamed but no doubt included earlier extensive histories, especially Greek ones. Besides Justin’s précis, a set of contents lists (prologi) of Trogus’ books survives; at times these throw light on what Justin chose to include and exclude.
**Livy**: Titus Livius of Patavium (59 bc–ad 17) devoted most of his life to a monumental history of Rome in 142 books, bringing it down to the middle of Augustus’ reign and consulting a broad range of older histories and other sources, Greek as well as Roman. Conscientious, relatively humane, and strongly patriotic, Livy found his history expanding almost unstoppably as he proceeded (he comments on this at the start of Book 31), while his own critical abilities stayed limited and his bias for Rome’s side of events often over-coloured his narrative. Books 1–10 survive (down to 293 bc), then 21–45 (from 218 to 167): his history of the Second Punic War (Books 21–30) is the longest, and most famous, full-length account, while in later books he gives much information about Hannibal’s later life. For this half-century he draws greatly on both Polybius and Roman authors – sometimes more or less paraphrasing Polybius while constantly adding details from elsewhere, which can have strange results. Unfortunately he is not that interested in Carthaginian affairs, though what he does narrate is valuable. Useful epitomes (Periochae) of nearly all the 142 books, of 4th-Century ad date, survive; most are brief, while those of Books 48–50 (the period of the Third Punic War) are much lengthier and offer important details.
**Nepos**: Cornelius Nepos, a contemporary of Cicero, included short biographies of Hamilcar Barca and his son Hannibal among a set of Lives of Eminent Foreign Generals. They provide useful items along with some foolish errors; his sources probably included Hannibal’s literary Greek friends Silenus and Sosylus.
**Plutarch** :Greek philosopher and biographer of Greek and Roman leaders, including several who had dealings with Carthage (Dion, Timoleon, Pyrrhus, Fabius Maximus, Marcellus). Plutarch used a range of sources, mostly sound ones, and is important whenever he touches on Carthaginian matters.
**Polyaenus**: Greek writer of the 160s ad, author of eight books on military and naval Stratagems, largely on Greek commanders but with some examples from Carthaginian history. Unfortunately his methods are often careless and some of his anecdotes implausible. Polybius: historian (about 200–118 bc) of the Mediterranean world for the period 264 to 146 bc, a leading Greek of Megalopolis in the Peloponnese. During years spent as an increasingly respected political hostage at Rome (167–150), and becoming a close friend of the eminent Scipio Aemilianus and a temperate admirer of Rome’s political system, he composed his Histories in forty sizeable books, analytical and argumentative as well as narrative, to explain how the Romans could make themselves masters of the Mediterranean world in less than fi fty-three years (219–167). He opens with a shorter narrative of events from 264, and later extended the work to end in with the destruction of Carthage; he was an eyewitness of this tragedy. His sources, whom he often analyses and criticises, all wrote in Greek but included pro-Carthaginian and early Roman historians. Like others, Polybius is interested in Carthage largely where she interacted with the outside world, especially Rome. His ponderous style and complex treatment of issues caused only Books 1–5 to survive in full, but Byzantine compilers in the 10th Century made lengthy extracts from the rest, while shorter excerpts are quoted by ancient and Byzantine authors.
**Strabo** :Greek scholar of Augustan times, whose seventeen-book Geography of the known world deals with places, peoples, cultures and even economics. Book 17 covers Africa, including a rather short section. | [
"The historical study of Carthage is problematic. Because its culture and records were destroyed by the Romans at the end of the Third Punic War, very few Carthaginian primary historical sources survive. While there are a few ancient translations of Punic texts into Greek and Latin, as well as inscriptions on monum... |
The American "Rust Belt" seems to be concentrated in one long strip of territory in and around the Midwest. Why didn't industry and factories spring up in the American south in the same way? | Iron ore from Michigan and Minnesota, coal from Pennsylvania and surrounding states, and limestone from Indiana and the Ohio Valley could all be brought to Great Lakes ports inexpensively. Areas near Chicago, Cleveland, and Detroit thus became the center of supply for steel, the primary component of both automobiles and appliances. (For Pittsburgh, proximity to coking coal outweighed the distance iron ore had to be brought.) Secondary elements such as hardwood and glass were also available nearby, while the multiple rail lines through Ohio and Indiana converging on Chicago offered competitive transport for components and finished products. As a result, a crescent around Detroit became the center of the automotive industry. Appliance factories were a bit more scattered, but seldom more than 300 miles from the rolling mills that supplied sheet steel. As new sectors, such as electronics, grew, they took advantage of the technical skills, machine tool industry, and supply networks already present in the region. A famous 1943 classification study by urban geographer Chauncey Harris showed [a striking geographic pattern](_URL_0_) for American cities dominated by manufacturing. Only after World War II did big industrial companies begin to establish branch operations in Sunbelt locations, once large-scale air conditioning made conditions for assembly workers (and delicate components) more tolerable.
It was the decline of the steel-related industries near the Great Lakes and Northeast in the 1980s that gave us the term "Rust Belt." The textile industry of the South had its own story of agglomeration near cotton suppliers and decline when faced with low-wage offshore competition, but that took place two decades earlier. | [
"The Rust Belt begins in central New York and traverses west through Pennsylvania, West Virginia, Ohio, Indiana, and the Lower Peninsula of Michigan, ending in northern Illinois, eastern Iowa, and southeastern Wisconsin. New England was also hard hit by industrial decline during the same era. Industry has been decl... |
why home deliveries are so common in the us | > Big things that are shipped on a pallet, like a TV, are delivered to a bigger shipping terminal.
Do you take the bus to pick it up, then?
> While for the US we constantly see package thief videos in /r/videos, with them just being dropped off in front of the door with no expected supervision or signature.
We could post lots of videos of packages just sitting there all day undisturbed, but that would be boring.
> What gives?
What gives with your system? It seems to pretty much suck. I ordered a vacuum cleaner to be delivered because I didn't want to have go to the store and buy and one and then to try to balance it on my handle bars on the way home, and now I have to go to the store anyway to pick it up? | [
"Today, mail is delivered once a day on-site to most private homes and businesses. The USPS still distinguishes between city delivery (where carriers generally walk and deliver to mailboxes hung on exterior walls or porches, or to commercial reception areas) and rural delivery (where carriers generally drive). With... |
How did allied soldiers get there supplies during the offensive against Germany? | Do you mean after D-Day ?
Immediately after D-Day the allies built two Mulberry Harbours, here is a picture : _URL_0_
The reason that they were needed is that the Allies had realised after the failure at Dieppe in 1942 that taking an already built harbour was too difficult. So, the invasion was based on beaches. This posed a problem in getting supplies to the invading troops. The Mulberry was the answer, ships could dock, be unloaded and then the cargo driven in trucks from the harbour to land.
The intention was that the harbours would last 3 months. The one on Omaha beach was destroyed in a storm on 19th June because it wasn't properly secured to the sea bed.
The one on Gold beach (later known as Port Winston) was secured to the sea bed and was in constant use for 6 months, at which point the Allies had taken Antwerp and switched supplies to there. If you look at the coastline at Arromanches some remains of the harbour can stiill be seen today, in fact at low tide you can walk out to the concrete cassions that made part of the breakwater. | [
"A memorandum to the British War Cabinet on 1 January 1917 stated that very few supplies were reaching Germany or its allies either via the North Sea or other areas such as Austria's Adriatic ports (which had been subject to a French blockade since 1914).\n",
"The Australian Red Cross reported dispatching a total... |
What is the most likley future of space travel? | Well the first step is the figure out when space travel will be worth it. In a mostly economic sense, at what point does dumping a very large amount of resources to supply a mission that won't return for at least a generation that has speculative benefits at best make sense? Well either we have developed more efficient methods (read: speed per unit energy) of space travel, we have discovered a new form (or a more efficient method of harvesting and harnessing current forms) of energy which is cheap, we have developed extremely long lasting replenish-able life support systems, and/or we are forced to by exogenous forces. I'll go over each of these in a little detail.
Currently, the most expensive part of space flight is getting from the surface of the earth to orbit. It costs roughly $450 million (source: _URL_0_) to launch a shuttle in 2011. This pretty much kills commercial space travel by itself. So, the first step for the future of mass space travel is a relatively cheap method of getting stuff into space. This means we need either A) a very cheap source of energy or B) new technology, like a space elevator. Neither are likely to be coming any time soon, but there are some emerging technologies like carbon composites (read: _URL_1_) that may eventually lead to cheap transport costs from the surface to orbit.
But lets say commercial travel isn't important to you. Ok, so we have one spacecraft, and it's on some sort of special mission, science or otherwise. So you don't care about the launch costs, because its mission is beyond the scope of money and resources. (There are some things money can't buy, and Mastercard will do you shit-all when a meteor is heading towards earth). Let's say the mission is science related ... discovering new systems, taking in data, doing experiments, etc. If the ship was big enough, it would probably be assembled in space. And any ship that was going to travel to another star would probably have to be rather large to hold all the systems needed for said trip. So now we're wondering about the structure of the vessel. Here are the main things to consider:
1) Will humans be on board? Probably yes. According to all current theories, information cannot be transferred faster than the speed of light. This makes remote control difficult as the vessel moves farther and farther away, and to risk such an object this way is not a good idea. As for an AI, we wouldn't be able to give it the capacity to make the correct decision in all possible scenarios (because we just can't be sure what will happen), and humans are probably more suited of whatever mission is at hand, even if it's just transporting people!
So this leads to issue:
2)The ship must be large enough to house all life support systems to keep a crew alive for years. (or the whole cryosleep while AI drives idea, but that's still way off and people have been working on cryogenisis for a while) A self sustaining environment that can also collect additional resources is actually one part of this problem that we pretty much could solve with our current technology! We would probably want to design the ship to have a spinning wheel too, to mimic gravity over such long trips. (Artificial Gravity ... not going to happen)
This leads to the last major (and probably what you're interested in most) problem:
3) Transportation technology. First off, the energy required for travel must be cheap, abundant, easy to store, and/or renewable. Basically, the ship can't be allowed to run out of energy. Under a conventional view, this means that the ship will collect energy as it travels while it propells itself through space. Ok, sure, we are probably at maximum 100 years away from a truly efferent method of converting and storing light energy. However, the problem is the maximum speed and maneuverability. There is no way for something with mass to move faster than the speed of light. Sure, we can get kind of close, and this could let us travel to near by systems over the course of decades. Then comes in the cost-benefit question again: Is it worth it? For now, no. Later? Maybe. And remember, with humans on board, you can't accelerate too fast without killing the crew.
So is there another method of travel that doesn't rely on conventional propulsion? Currently ... no. Wormholes have been debunked for the most part, and any method involving the compression of space would take such a dense amount of energy in space that it becomes nearly impossible to store and extremely unstable during operation.
so now the TL;DR: version:
Commercial space flight is extremely limited, mainly by the high surface to orbit costs. Even if not commercial, all projects would have to undergo some cost-benefit analysis. This overall makes it so interstellar travel is many decades off at least. Regardless of when the technology catches up, humans will most likely be on board such spacecraft. Thus, long lasting life support systems are needed, as any significant journey will take at the minimum several decades. This is because faster than light speed travel is impossible, and alternate methods are highly improbable. Possible changes to human life spans or hibernation may ease limitations on lengths of trips. Future ships, when or if they are developed, are likely to be designed to operate over the course of many generations.
But in the end, it really all comes down to economics: When will the perceived benefits of such travel outweigh the perceived costs?
And besides, I like it here on Earth just fine! | [
"Features of the postulated future include an Earth governed by a World Federation in which Brazil has become the paramount great power, with Terran space travel monopolized by a Brazilian-dominated agency called the \"Viagens Interplanetarias\" (\"Interplanetary Tours\" in Portuguese). Interstellar travel is limit... |
does your body keep taking in water when you get wounded underwater? | No question is stupid. People who say that a question is stupid are the stupid ones themselves.
Anyway, no, water wouldn't fill into your body. Your heart is constantly pumping blood throughout your body, meaning that it's generating pressure to move all of your blood around (this is referred to as one's blood pressure). If you get a major wound, the heart will still continue to pump blood, but since the blood has an opening to escape from, and it's constantly being pumped under pressure, it's going to want to move out of the wound quite quickly to an area of less pressure. This means that instead of water moving into the wound, the wound would instead push water away from it, with blood. | [
"Urgently lifting an injured or incapacitated casualty from the water is a significant problem especially where there are few rescuers, the sea is rough, the boat has high sides or the rescuers on the shore cannot get in or close to the water to help.\n",
"If the diver is still underwater when the laryngospasm re... |
Why weren't 6.5mm cartridges more popular after WW1? | In general, nations retained the same cartridges used in ww1 up until and through ww2. Like with bolt-action rifles rather than semi-automatic ones, this was mostly due to cost during the interwar years, and then the need to maintain production of arms and ammunition during the war.
Several countries realised the limitations of the ww1 rifle calibers and tested or even attempted to introduce new ammunition and/or new service rifles. The British tested .256 (6,65mm) and .276 (7mm) ammunition and the French started a switch from 8x50Rmm to 7,5x54mm. The Italians actually attempted to switch from 6,5x52mm to 7,35x51mm in 1938, but the project did not get far before the war broke out. The US also tested the .276 (7x51mm) Pedersen cartridge and actually adopted it for the new M1 Garand service rifle, but reversed the decision after verifying that the Garand would work with hte heavier .30-06 cartridge.
There were extensive stocks of earlier rifle caliber weapons left from ww1 - rifles, LMGs and HMGs alike. Adding to that were the fact that production was tooled and streamlined for the older cartridge - setting up new production lines are usually both expensive and time-consuming meant that the older cartridges had to soldier on.
Lack of money to re-tool production lines before the war, with demobilisation and then the Great Depression throwing a monkey wrench into military re-armament plans and then the urgent need for arms and ammunition in the field once the war had started prevented most of these projects.
Instead all sides attempted to improve ballistics and reduce recoil by introducing lighter bullets, spitzer bullets and otherwise improve existing cartridges. | [
"World War II spoiled the commercial introduction and spread of the 6.5×68mm. The cartridge became popular after World War II due to its high performance and flat trajectory, when German hunters were allowed again to own and hunt with full bore rifles. The 6.5×68mm's performance also made it that hunters who had pr... |
why buy an expensive computer monitor if a hdtv of the same size is cheaper and has the same resolution? | Monitors have better response times, more accurate colours and some even have features like USB hubs.
TV's don't have fast response times and therefore have a lot of input lag, which is fine for movies and such, but for applications and games, monitors are better. TV's process the image to try and make it look as good as possible, but it doesn't mean the colours are accurate, which is important for things like photo and video editing. This processing takes time, so a TV can have a response time of anywhere from 10 to 60 milliseconds, but a monitor usually has response times or less than 5ms, often 2 or even 1ms. | [
"In 2011 Bennie Budler, product manager of IT products at Samsung South Africa, confirmed that monitors capable of 1920×1200 resolutions aren't being manufactured anymore. \"It is all about reducing manufacturing costs. The new 16:9 aspect ratio panels are more cost-effective to manufacture locally than the previou... |
why is it that when i'm laying down i pitch black darkness it randomly feels as if i'm falling or the bed is tipping. | I think I just saw this exact thing explained on reddit earlier. Basically, as you fall asleep, your body fully relaxes. Because your mind is still partially conscious, it tries to justify the sensation to itself. It recreates the closest feeling it's experienced. This often manifests itself as a freefall or spinning motion. You'll notice that if you move during the sensation it will stop.
Hope this helped!
P.S. First time explaining! | [
"\"“I was in bed and about to fall asleep when I had the distinct impression that “I” was at the ceiling level looking down at my body in the bed. I was very startled and frightened; immediately [afterward] I felt that, I was consciously back in the bed again.”\"\n",
"This recollection is brought to an end when h... |
how do phones and computers transfer audio to headphones? | Sound is transmitted as a voltage signal through wires. The voltage changes just like the soundwave, and this goes into tiny magnets in headphones, or speakers, or telephones. The magnets shake the speaker back and forth as the voltage changes, and this movement makes pressure waves on the air. The pressure waves we hear as sound. The whole process works in reverse too, and that's how microphones work.
This also means that if you look at a soundwave picture (or wave form), you are actually also looking at a [graph over time](_URL_0_) of the in and out movement of the speaker you're listening to. | [
"Headphones (or head-phones in the early days of telephony and radio) traditionally refer to a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an... |
what happens to deceased pigeons in major cities so that you rearly see their corpses. | Seems like a lot of animals go somewhere secluded to die. There are tons of raccoons, possums, and stray cats and dogs in my city too, but I never see any dead ones unless they've been run over. | [
"There is ample reason for the concerns of pigeons damaging property, due to their size and proximity to people and their dwellings. Pigeons often cause significant pollution with their droppings, though there is little evidence of them driving out other bird species. Pigeons are labeled an invasive species in Nort... |
Can we apply the laws of physics universally no matter which direction or reference of time we are observing? | Not always.
For example the famous law of Conservation of Energy:
If that spacetime is standing completely still, the total energy is constant. But that is not the case, so energy is not totally conserved. Energy conservation becomes tricky when time is bent.
A good example is Redshift of photons. They are losing energy over time and undergoing Redshift. That energy is lost over time.
This is explained by [Noether's Theorem](_URL_0_) | [
"The equations used in physics to model reality do not treat time in the same way that humans commonly perceive it. The equations of classical mechanics are symmetric with respect to time, and equations of quantum mechanics are typically symmetric if both time and other quantities (such as charge and parity) are re... |
WWI letter found in cupboard in Lübeck, Northern Germany. I need your help and knowledge to figure it out. | I just skimmed through it and couldn't read everything, but here is a short summary:
Old woman (and her husband) cares for her granddaughter but can barely afford it. Her daughter, the child's mother, seems to be dead and now she searches for her son-in-law, who is at war. There seems to be a problem with the relationship, perhaps they are divorced or weren't married at all. The grandma applied for "Kriegsunterstützung" (money) but she needs a document ("Anerkennung") from her son-in-law.
The Military answers that he doesn't belong to this Bataillon.
---
Edit:
# & nbsp;
Gehorsamstes Gesuch
der Frau XXX
in Zinten
um Gewährung eines
Bescheinigungs(?) ihres
Enkelkindes
An das hochgeehrte
Königliches Ers. Bat. Inft.
Regt. Nr. 59
# & nbsp;
Zinten d. 24/6. 1915
Eurem(?) hochgeehrten König-
lichen Regt. Nr. 59
erlaube ich mir folgendes
zu unterbreiten: Da meine
XXX mit
den Schornsteinfegergeselle
XXX
umgänglich(?) verkehrt hatte
gebar Sie von demselben
ein XXX
XXX
Da aber jetzt die Tochter
schon über ein Jahr tot
ist, und der Vater von
dem Kinde im Kriege,
sind wir alte Leute doch
nicht im Stande das Kind
zu ernähren, mein Mann
zählt schon 75 Jahre und
Ich 65 Jahre alt wir
# & nbsp;
wir können uns selber
nicht mehr richtig ernähren
noch vielmehr das Kind.
Und da ich doch auch ...
das Königliche Bezirkommando
zu Braunsberg(?) geschrieben
habe wurde mir die Bitte
nicht abgeschlagen zur Ge-
währung eines(?) Kriegs-
unterstützung. Da nun
aber noch nicht genug Briefe(?)
sind weil ich XXX nicht
verklagt habe, sollte
ich am XXX noch schreiben
daß er die Anerkennung
seines Kindes nämlich(?) in
paar Worte auch ...
lassen soll von seinem
Hauptführer, hat sich XXX
noch garnicht gemeldet.
Und wo doch so lange
meine Tochter gelebt hat immer
gezahlt hat, kümmert
er sich doch jetzt garnicht
# & nbsp;
garnicht um sein Kind.
Nun hätte ich wohl den
Hochwohllöblichen Herrn
sehr gebeten und komme
mit der hochge...
Bitte doch für mein Enkel-
kinde die Beglaubigung
gütigst gewähren zu wollen.
In der Hoffnung keine
Fehlbitte(?) getan zu haben
zeichnet sich gehorsamst
Frau XXX geb XXX
in Zinten Kirchengericht 2
# & nbsp;
Gehorsamst
Bitte mir doch dasselbe
zur Empfangnahme
übersenden zu wollen.
Adresse
An XXX
Ers. Batl. Inft. Nr. 59
# & nbsp;
Answer:
den 1. Juli 1915
der Einsenderin
zurück mit dem Bemerken(?), daß XXX dem
Bataillon nicht angehört und auch bisher nicht
angehört hat.
Oberleutn. und ...
# & nbsp;
| [
"His writings were found by chance in 1993 in the manuscript store of the Berlin State Library. The surviving part covers a range of 25 years between 1625 and 1649. The book was folded from 12 sheets of paper which he bought at the end of the war in 1648 to write a fair copy of his notes. The 192 pages tell of a 22... |
What happened to the land and the debris of war such as weapons and vehicles that were left after long and destructive battles like Verdun or Stalingrad? Basically, who cleaned up the mess and how did they do it? | Note that many areas which have seen prolonged fighting in modern wars *haven't* been completely cleaned up, with some still containing dangers such as live explosives.
With this in mind, I'd like to ask a follow-up question: which areas have seen prolonged fighting with significant leftover debris/ordnance that *was* cleaned up, and why was the decision made to clean up these areas and not others? | [
"In the aftermath of a war, large areas of the region of conflict are often strewn with \"war debris\" in the form of abandoned or destroyed hardware and vehicles, mines, unexploded ordnance, bullet casings and other fragments of metal.\n",
"Large portions of the buildings were destroyed after the war. Until 1947... |
Do the planets all orbit the Sun on the same plane as Earth like all the models depict, or do the planets orbit the Sun like how we depict electrons orbiting an atom? | All planets orbit on the same plane (more or less, within a few degrees) as the Earth. Check out [this response from the FAQs for more info](_URL_0_). | [
"Most large objects in orbit around the Sun lie near the plane of Earth's orbit, known as the ecliptic. The planets are very close to the ecliptic, whereas comets and Kuiper belt objects are frequently at significantly greater angles to it. All the planets, and most other objects, orbit the Sun in the same directio... |
how che guevara being a marxist and everything that capitalist america can’t stand for ended up being such a pop culture icon in america? | I am not American, and dont really know but i would say that he was originally adopted by counter-culture because he **was** everything that Capitalist America didnt stand for. Counter-culture then became 'the cool' thing and it sort of just took off from there.
[Here's](_URL_0_) a little overview done by the BBC on how that image has become so famous and where it originated from. | [
"Amongst the youth of Latin America, Guevara's memoir \"The Motorcycle Diaries\" has become a cult favorite with college students and young intellectuals. This has allowed Guevara to emerge as \"a romantic and tragic young adventurer, who has as much in common with Jack Kerouac or James Dean as with Fidel Castro.\"... |
How did WWII Navy pilots find the aircraft carrier after a mission? | More input is always welcome; while we wait, you may be interested in [this thread asking the same question](_URL_0_). u/thefourthmaninaboat provides the general overview, while u/DBHT14 provides a specific view at the USN, specifically at Midway. [There's also this prior thread](_URL_1_) with a tick more discussion, also featuring the same two users.
I also highly endorse u/DBHT14's recommendation of Lundstrom's *The First Team*; it's a chunky thing, but there is just no better book for US carrier operations in the early part of the Pacific Theatre. | [
"An extensive search for the aircraft was organised, which included the Royal Navy ships HMS \"Barhill\" and HMS \"Gambia\" as well as the Maltese civilian salvage vessel \"Sea Salvor\". The search effort involved the pioneering use of underwater TV cameras, developed by a team at the UK Admiralty Research Laborato... |
why is it so difficult to make reflections in video games? | Doing a reflection essentially means drawing the scene twice, once from the camera's point of view and once from "within" the mirror.
Drawing the scene takes a lot of processing power. If the game runs at say 60 fps normally, having to draw the scene twice will make that framerate drop significantly.
That said it should be possible if the developers are clever about where they place mirrors. For example if a lot of the game has wide open spaces with lots of stuff in it, but mirrors are only ever in enclosed spaces with not much in them then it could work ok.
But it's still a lot of work to implement mirrors, and generally do players care about them that much? The time is usually better spent on other features. | [
"The team wanted to avoid punishing the player for applying everyday logic in \"Maniac Mansion\". Fox noted that one Sierra game features a scene in which the player, without prior warning, may encounter a [[game over]] screen simply by picking up a shard of glass. He characterized such game design as \"sadistic\",... |
About to begin studying History at University. Anything I should know? | Be prepared to change your major simply because the university experience is all about discovery - including what really sets you on fire. It may be history, but it may be something else. Be agile and flexible. If history is the focus of your passion after the dust settles, that's a great place to put one foot, but since you have two, consider carefully what else excites you. Your ability to carve a unique niche for yourself is not your passion for history (others will have the same for the field(s) of your focus). Rather, it is what else you bring to the table - economics, chemistry, biology, an understanding of culture, sociology, house design, textiles, archaeology, meteorology - you name it, but it will be the combination of things you bring to the table that makes the difference.
Also, seek out and obtain practical experience. If you are to be employed as historian, there is a better than even chance it will be as a public historian, not as a teacher/professor. Volunteer at a local house museum or at an excavation. Find work on campus in the archive or in town with an architectural firm or construction firm that works with old buildings. Any of these things could be the foundation for a career that in all likelihood you can't even imagine, but which can be rewarding. But as indicated in the first paragraph, prepare to be agile and flexible.
And be prepared to be homesick. That's just part of it. It gets better, but it can be miserable for a while. Soldier through.
And most of all, best of luck. | [
"The history of the University is usually traced to 1841. It was in that year that five young men who were employed by local industrialist Frederic Schwann, who had been born in Frankfurt, approached their employer for support in establishing a new subscription library and some elementary educational classes, ‘to s... |
What (specifics) do we know about clothing of Northern/Central European men during the late Bronze- / early Iron-age? | (Don't worry about the flair, I removed it - the filter picked up on "sport".)
I'm not entirely sure of what you mean about a culture generally clad in furs and skins, because textile use was most common by 600 BCE, so I'm going to just look at clothing in general from around this time. The best preserved Bronze Age clothing is, unfortunately, from centuries earlier than you're looking - from graves in Denmark, now held at the National Museum. Instead, let's turn to Hallstatt, Austria, a particularly important site which gave its name as an anthropological label to a European culture, around the turn from the Late Bronze Age to the Iron Age. There are not actual clothes there, thanks to the tradition of cremation, but we do have information about the textiles from scraps preserved in the local salt mine. (We don't know exactly why they're there. Possibly they were leftovers from worn-out blankets and clothing relegated to mine use.) Wool was the most commonly-used textile; typically, coarser wool was used in [plain-woven](_URL_0_) textiles and is seen on sheepskins, while [twills](_URL_3_) and other special weaves used nicer fibers - instead of using the fleece as it was found on the sheep, which was common earlier in the Bronze Age, they were carding it and sorting the fiber. By the time you're interested in, an even twill was the more commonly-used weave. The sheep were generally light or dark brown, with light brown sheep preferred for dyeing purposes. Blue (woad), red (lady's bedstraw/madder) and yellow (weld/dyer's broom/sawwort) dyes were used in the Bronze Age, made from plants native to the area; later in the Iron Age, the people of Hallstatt started to use dyes that had to have been imported, like kermes and European cochineal (insects that could be dried and crushed to produce a more vibrant red) and saffron, as well as double-dyeing, dipping a fabric in a dye bath of one color and then a dye bath of another, to produce green and a reddish blue.There seems to be some disagreement in my sources about whether madder and kermes could be found in Early Iron Age Hallstatt, but we do know that they started to use more color patterning around that time. Stripes had been used since the Early Bronze Age, because they're pretty easy to produce, but by the end of the Bronze Age more complex patterns appeared, checks and twill plaids that you might see on clothing today.
We do know that linen was also used in Europe at this time, but unfortunately it doesn't survive as well as wool, so we just don't have quite the same level of understanding regarding weaves and colors. (Silk started to be imported in the Iron Age, but that was just for elites and not something you're going to want.)
Where these textiles for clothing at Hallstatt were made on large warp-weighted looms, narrower bands were woven with [tablets](_URL_4_) in detailed patterns - with actual design motifs as well as patterns like stripes, checks, and reps (raised stripes). These bands could be sewn as edgings or facings on clothing, or used as belts on their own.
We do have one shoe extant from Hallstatt! While [this is a link to an image from Pinterest](_URL_1_), it matches the photos I've found in academic publications, so I'll share it with you. The Hallstatt shoe is essentially a shaped piece of leather wrapped around the foot and sewn.
So back to the basic question - what can I tell you about men's clothing construction to help you make your garb? Those Early Bronze Age men from Denmark were buried in "wrap-around kilts of various lengths, large oval or kidney-shaped cloaks, footwear consisting of simple hide shoes, strips of cloth, and in one case a cloth shoe with the sole sewn on" - potentially everyday dress, potentially elite dress, potentially ritual/death dress. Trousers seem to have started to appear in some regions in the Middle Bronze Age, while the amount of bronze jewelry and pins increased. Styles of jewelry and the manner of wearing it differ strongly by region, so there's no general way I can suggest you wear your dress or fibula pins - you'd have to decide on a very specific area. Though a very elite example, the Hochdorf grave in Württemberg (dated to 540-530 BCE) would be quite helpful ... except that all the sources I can find just describe the man in the grave as wearing "clothing". Trousers, thigh-length tunic, and cloak were the thing a few centuries into the Iron Age, so that is likely your best bet.
Grömer, Karina. "Textile Materials and Techniques in Central Europe in the 2nd and 1st Millennia BCE", *Textile Society of America Symposium Proceedings* (2014).
Grömer , Karina and Helga Rösel-Mautendorfer. "The textiles of Hallstatt", *Colours of Hallstatt: Textiles Connecting Science and Art* (2012).
Rebay-Salisbur, Katharina. *The Human Body in Early Iron Age Central Europe: Burial Practices and Images of the Hallstatt World* (2016)
Smith, Heather. "[Celtic Clothing During the Iron Age- A Very Broad and Generic Approach](_URL_2_)"
Sofaer, Joanna, Lise Bender Jørgensen, and Alice Choyke. "Craft Production: Ceramics, Textiles, and Bone", *The Oxford Handbook of the European Bronze Age* (2013).
Sørensen, Marie Louise Stig. "Identity Gender, and Dress in the European Bronze Age", *The Oxford Handbook of the European Bronze Age* (2013).
von Hofacker, Racheli. "Oh Shoe . . .", *Colours of Hallstatt: Textiles Connecting Science and Art* (2012). | [
"The Iron Age is broadly identified as stretching from the end of the Bronze Age around 1200 BC to 500 AD and the beginning of the Medieval period. Bodies and clothing have been found from this period, preserved by the anaerobic and acidic conditions of peat bogs in northwestern Europe. A Danish recreation of cloth... |
How true is the statement that England abandoned Australia after the Fall of Singapore in WW2? | The British released three divisions of volunteer Australians from the Western Desert to go back to Australia in the spring of 1942. These troops, the 6th, 7th and 9th infantry divisions played a key role in driving the Japanese army out of Papua New Guinea in 1942 and early 1943. They contained by passed Japanese garrisons in New Britain and the northern Solomon islands in 1943 and 1944 and played a role in liberating some of the islands in Indonesia in 1945, However, these were Australian troops. No British troops were sent to Australia, The United States sent their 32nd and 41st Infantry divisions to Australia in early 1942.
The Royal Navy did sent the County class heavy cruiser Shropshire to the Royal Australian Navy, to replace their heavy cruiser Canberra, that was sunk during the battle of Savo Island on August 10th 1942. The Brits also sent some Spitfire fighters and Beaufighter and Beaufort attack planes to Australia. However, some of the Beauforts were built in Australia and the United states sent more than twice as many warplanes to equip the Royal Australian Air Force than the British did. So, the British did send a limited amount of assistance to the Australians, but the Americans sent much more.
Sources: "World War II Airplanes: Vol. 2" by Enzo Angelucci and Paolo Matricardi pages 255-263
"Victory at Sea: World War II in the Pacific" by James Dunnigan and Albert Nofi | [
"The another major issue brought up around this time was national defence. Following independence, the British were still defending Singapore, but had announced they would be withdrawing by 1971, due to pressures at home and military commitments elsewhere in the world. This caused considerable alarm locally, partic... |
Quick history of astronauts countering Van Allen radiation belts? | I don't have time for a full history, but broadly speaking we've known that space was radioactive since the very early days of the Space Race. Explorer 1 was the first satellite to carry a geiger counter, which went crazy when it entered the radiation belts. This led one of the members of the science team, Ernie Ray, to famously exclaim "My god, space is radioactive".
For most astronauts, the radiation belts aren't actually too much of an issue, as they tend to orbit at a lower altitude than the lower extent of the inner radiation belt. This includes the likes of the ISS. Obviously it's a different question for the Apollo astronauts, as they had to pass through them in order to reach the moon. NASA was well aware of the existence of the radiation belts by this stage, and attempted to minimise the radiation exposure by passing through the sparsest area of the radiation belts, and doing so as quickly as possible.
It should be noted that the ISS crew members are instructed to retreat to more shielded areas of the station during period of increased geomagnetic activity, to protect them from excess radiation exposure. | [
"In addition to the charged particles of the Van Allen Belts, the spacecraft were also designed to measure cosmic rays, galactic radio emissions, magnetic fields, radio propagation, and micrometeoroid flux. They were also meant to study artificial radiation belts created by high altitude nuclear tests, but the rati... |
how isaac newton was able to test and prove that an object in motion will stay in motion unless acted upon by another force, when you can never truly have something without other forces acting on it to prove his theory | Isaac Newton did not perform experiments and describe the results. He did make observations, drawing on the work of other authors as well, and then used *reasoning* to formulate general rules according to which he supposed the world worked. An emphasis on reasoning rather than experimentation is one reason that science was called "natural philosophy" in his day.
You couldn't test the ideal object with no forces acting on it. But you could still put his logical conclusions to the test by observing objects that appeared to be in balance and applying an outside force to them. Even if the underlying laws were not necessarily verifiable, the logical implications could be tested and showed this was a consistent and (mostly) accurate set of predictions. | [
"While Newton was able to formulate his law of gravity in his monumental work, he was deeply uncomfortable with the notion of \"action at a distance\" that his equations implied. In 1692, in his third letter to Bentley, he wrote: \"\"That one body may act upon another at a distance through a vacuum without the medi... |
why didn't the usa drop nuclear bombs on tokyo but dropped them where they did? | You can read the deliberations that the US scientists and military men had in May 1945 over the first nuclear targets [here](_URL_0_). The possibility of bombing the Emperor's palace was discussed but dismissed — they didn't want to kill the Emperor and the high command, they wanted to induce them to surrender. They felt the best way to do this was to demonstrate the bomb's power on unbombed targets — the few cities of any consequence that had escaped the ruinous firebombing of Japan. The initial targets that fit the criteria were Kyoto, Hiroshima, Yokohama, Kokura, and Niigata. Kyoto was removed by Secretary of War Stimson himself because of its cultural/religious value. Yokohama was firebombed soon after the meeting so it dropped off the list. A new city, Nagasaki, was added to the final list. The list of targets, by priority, were then Hiroshima, Kokura, Niigata, and Nagasaki. Hiroshima was bombed on August 6, 1945; Kokura was meant to be the primary target for the second bomb on August 9 but cloud cover meant that the secondary target, Nagasaki, was bombed instead. A third bomb was being readied for the end of August. There were rumors that Tokyo might have been its target but all atomic operations were halted on August 10th when it became clear that Japan might be ready to surrender. | [
"On 30 June 2007, Japan's defense minister Fumio Kyūma said the dropping of atomic bombs on Japan by the United States during World War II was an inevitable way to end the war. Kyūma said: \"I now have come to accept in my mind that in order to end the war, it could not be helped (shikata ga nai) that an atomic bom... |
Why is brain death final? Like, why can't we restart or reboot a brain that's been dead for only a few hours? | Yes, it is decay (aka mass cellular death).
Neurons have *huge* metabolic needs. If you cut off their oxygen supply, neurons lose their ability to maintain their ionic gradients fairly quickly. This results in depolarization, excitotoxicity, and eventual cellular death. Once they're dead, they're dead, no bringing neuronal tissue back from that. | [
"Brain death may result in legal death, but still with the heart beating and with mechanical ventilation, keeping all other vital organs alive and functional for a certain period of time. Given long enough, patients who do not fully die in the complete biological sense, but who are declared brain dead, will usually... |
Why don't we just point Hubble at Pluto instead of waiting a decade for a satellite to take pictures of it? | We did. You can find some two sample images [here](_URL_0_), but you should direct your view to the top left of each half, which show the actual Hubble images. Each pixel is over 100 miles across, so we don't really see much. Pluto is just really far away, and our telescopes don't really have the resolving power, and even recent advances in ground-based telescopes, which have larger diameters but contend with waviness of the atmosphere, have only done [marginally better](_URL_2_) (compare to [Hubble's resolution](_URL_1_)). | [
"On February 12, 2015, NASA released new images of Pluto (taken from January 25 to 31) from the approaching probe. \"New Horizons\" was more than away from Pluto when it began taking the photos, which showed Pluto and its largest moon, Charon. The exposure time was too short to see Pluto's smaller, much fainter, mo... |
A question about Human cell regeneration. | **Neurogenesis**, which is the generation of new neurons, only occurs in certain parts of the adult brain. Many of the neurons you are born with are, in fact, the ones you're stuck with until they or you die. However, even "permanent", non-replicating cells need to be replenished; over the course of 5 or so years, every neuron will essentially have been rejuvenated with new versions of their old parts (new amino acids replacing the old, and so on). Think of it as gradually replacing parts of a car over the years. After 5 years of replacing the tires, exhaust pipe, and other parts, the car will still be that same car, but rejuvenated. Pretty sure they were referring to this phenomenon in QI. | [
"One of the most promising sources of heart regeneration is the use of stem cells. It was demonstrated in mice that there is a resident population of stem cells or cardiac progenitors in the adult heart – this population of stem cells was shown to be reprogrammed to differentiate into cardiomyocytes that replaced t... |
how do integrated circuits/electronics work | There are a handful of basic building blocks for any circuit: resistors, capacitors, inductors, and transistors.
An integrated circuit as you'd have seen it in the 1970s would consist of 10 to 30 transistors, and less than 5 each resistors and capacitors.
Today due to advances in technology, the number of transistors can be in the millions or even billions in some of the really advanced chips.
Transistors are very important to electronics because they're made of "semiconductor" materials - primarily silicon. Thus it is possible to make a transistor conduct current (on), or impede current (off) on command by applying a voltage or current. There are several kinds of transistors that behave in slightly different ways, so I'll skip the details.
The differing behavior of each type of circuit depends therefore on the arrangement of the basic components. | [
"An integrated circuit is a miniaturized electronic circuit that has been manufactured in the surface of a thin substrate of semiconductor material. Integrated circuits are used in almost all electronic equipment in use today and have revolutionized the world of electronics. The integration of large numbers of tiny... |
what is the line between the first amendment and hate crimes? | Ahoy, matey! Yer not alone in askin', and kind strangers have explained:
1. [ELI5: The line between freedom of speech and breaking the law. Eg racism ](_URL_4_) ^(_13 comments_)
1. [ELI5 how can we prosecute hate speech if the First Amendment says we can't abridge the freedom of speech. ](_URL_1_) ^(_15 comments_)
1. [EIL5: Why is hate speech not protected speech? ](_URL_2_) ^(_37 comments_)
1. [Are there any limitations to free speech in the US? ](_URL_3_) ^(_._)
1. [If America is the land of free speech, then why is it not okay to dislike certain groups of people? ](_URL_0_) ^(_._)
| [
"The Matthew Shepard Act expanded the federal hate crime laws to include gender, gender identity, and sexual orientation. In order to qualify as a federal hate crime in the United States, the crime must include successful or attempted bodily injury due to the use of firearm, explosives, weapons, fire, or incendiary... |
why is hemp so much better than trees for making stuff? | The real value in using Hemp over traditional forest wood for cellulose based products is the way the two are cultivated. Even a small grove of trees takes years for the wood to mature and be usable, where as Hemp has a standard growth rate of only a few weeks. It is also a very good replacement for other production sources in the textile industry due to the nature of its fibers and the way it can be used much like cotton.
[Further Reading: See "Uses"](_URL_0_) | [
"Hemp is considered by a 1998 study in \"Environmental Economics\" to be environmentally friendly due to a decrease of land use and other environmental impacts, indicating a possible decrease of ecological footprint in a US context compared to typical benchmarks. A 2010 study, however, that compared the production ... |
Why do I see RGB when I look away from a projector light? | This is because the DLP projector is rapidly alternating between projection of the red, green, and blue component images. This is called the 'rainbow effect.'
[Wikipedia has an entry on it](_URL_0_) | [
"RGB (Red, Green, Blue) describes what kind of \"light\" needs to be \"emitted\" to produce a given color. Light is added together to create form from darkness. RGB stores individual values for red, green and blue. RGB is not a color space, it is a color model. There are many different RGB color spaces derived from... |
How much of a presence did the Inca Empire have in the rainforests east of the Andes? What did they call the natives of the Amazon region? | Actually, not as much as you might expect. [Tawantinsuyu](_URL_0_) reached across the whole of western South America, yet its most glaring geographical boundary is not the Pacific, but the Amazon Basin. Groups in the Amazon were known to an extent by Andeans and coastal dwellers, but it is a dialogue archaeologists are still sussing out. It is possible that Amazonian groups could get over the Andes through passes in what is now northern Peru, bringing ceramic technologies to the mountains and western coast as well as their own cosmological input. Sites like Chavín de Huántar popularized and spread an ideology that affected some five hundred miles of coastline - with distinctly Amazonian aspects in its icons and outlook.
We have evidence that many Andean civilizations skirted the Amazon - the Wari made one of their trade routes out of Ayacucho toward Cuzco along the eastern edge of the Andes at some 1000 m above sea level, along the lower *yungas* foothills. Likewise, the Inca named their northeastern quadrant *Antisuyu*, for their allies there the Antis. Undoubtedly elements of the Amazon made their way into Cuzco, the heart of the empire - tropical fruits and plants are accessible today, as then, in the daily markets of the Cuzco Valley. However the Amazon doesn't lend itself to conquest and control like open mountain peaks and passes passes do, or wide coastal deserts and river valleys. The severe altitude difference for Andeans like the Inca meant that pneumonia and sickness could decimate military movements into the jungle. So for the Inca, whose empire was one of the most direct and bureaucratically-driven polities ever to develop in South America, why throw an empire's resources on a space that could never be directly controlled? Many of its resources could be curried through clever agriculture in the yungas or political alliance/marriage with constituent groups of that region.
The Sacred Valley, which holds Machu Picchu, Ollantaytambo, Choquequirao, Pisac and many other royal estates of the Inca, was thus supported as a lush hinterland of the empire, even as it stood at a fringe of the empire. Machu Picchu and Ollantaytambo served both as verdant oases for the Inca and his retinue and as excellent defensible fortresses - a conscious projection of Inca dominion on its most consistently vexing frontier. In a way, the strongest presence of the Inca state in the east was after the Spanish arrived and took Cuzco from the Inca. Moving up through the Sacred Valley to the yungas beyond, the Inca established themselves at Vilcabamba, beyond the reach of Spain for some decades. Aided in this by groups like the Antis and Chunchos, the Inca state and its religion persisted until its complete discrediting and decapitation by the Spanish.
Now, I'm not really an expert on Amazonian groups, but I do understand that they were on some level were in contact with coastal and mountain groups in South America. Trade and associated ideas changed hands and minds for millennia - and yet even the Andes' strongest direct power could only work superficially with a whole swath of a continent. The dialogue between the coast, the mountains, and the forest is definitely one of the biggest questions out there for South American archaeology. | [
"In 2017, the 5,972,606 indigenous people formed about 25.7% of the total population of Peru. At the time of the Spanish invasion, the indigenous peoples of the rain forest of the Amazon basin to the east of the Andes were mostly semi-nomadic tribes; they subsisted on hunting, fishing, gathering and migrant agricul... |
What plants have gone extinct along with animals over the years? | Well, I'm not a scientist, but Wikipedia's [entry](_URL_1_) on paleobotany seems fairly thorough, and it links to a list of [extinct plants](_URL_0_). | [
"The plant was long thought to be extinct but a small population was discovered in 1998 by Stedson Stroud. As of 2011, it was considered \"effectively extinct in the wild\" by experts at Kew Botanical Garden because there were no longer any flowering plants left in the wild. Only one adult plant was left by 2010, a... |
How powerful can placebo's be and could they be a legitimate replacement for expensive and complicated medication? | 30% of the time they work, so if you have a really expensive medicine that works 35% of the time, placebo can be an alternate. | [
"A systematic review concluded that \"tricyclic antidepressants and traditional anticonvulsants are better for short term pain relief than newer generation anticonvulsants.\" A further analysis of previous studies showed that the agents carbamazepine, venlafaxine, duloxetine, and amitriptyline were more effective t... |
How old might the oldest conceivable DNA sample on Earth be? | Digging a little deeper I found this study where [DNA was amplified and sequenced from a 120-135-million-year-old weevil](_URL_0_) which is cool and all, but the answer I'm really looking for would come from a biophysics study I think. I'm finding it hard to belive that nobody has done an experiment where they have stored pure DNA under ideal preservation conditions and recorded its half-life. Even if this was done for a few years one could make some very good extrapolatons I would think, or maybe not? | [
"In 2013, a German team reconstructed the mitochondrial genome of an \"Ursus deningeri\" more than 300,000 years old, proving that authentic ancient DNA can be preserved for hundreds of thousand years outside of permafrost.\n",
"In 2013, a German team reconstructed the mitochondrial genome of an \"Ursus deningeri... |
_URL_0_ can draw my family tree back to e.g. Charlemagne, Constantine the Great and Philip II of Macedon. Is this actually a reliable tool? | I don’t know that this is strictly a history question. You may want to ask it over at r/genealogy. However, as an avid genealogist I can tell you that you are absolutely right to be skeptical.
Statistically, every person of Western European descent is a descendant of Charlemagne. In genealogy what matters is whether or not you are able to prove it. Do you have actual documentation in the form of historical records (records of birth or marriage specifically, tying your ancestors, all of them, in an unbroken line back to some royal figure)? Documentation is not someone else’s family tree that they uploaded to the internet.
Places like FamilySearch and _URL_0_ are rife with false genealogies because many people don’t do proper research and piggy back off of what someone else has compiled, never checking for errors, never bothering to verify anything. People just love to be able to say they’re descended from royalty. This isn’t to say that those websites are useless. They can in fact be extremely useful. But if you see a tree taking you back to some Roman or pre-Roman nobility I would guarantee it is a fake.
The familial relationship between the Frankish nobility, of which Charlemagne was a member, and the earlier Roman elite is something that is still being debated by historians and genealogists. So any family tree telling you it can connect Charlemagne to the Romans would be cutting edge research, let alone connecting you all the way that far back.
It should be noted that it actually is possible to connect yourself through the documentation process to old European nobility, including Charlemagne, by means of what are known as “gateway ancestors.” Gateway ancestors were real people, often Europeans who came to the Americas in the 1500’s and 1600’s who were themselves able to prove descent from nobility. It is possible to prove descent from such gateway ancestors and many Americans are able to do just that, myself included. These gateway ancestors are really the only way a modern person could trust their descent from the old nobility of Europe.
Again though, it requires thorough vetting of the physical records. And even if you have a gateway ancestor or five and can prove it in the records, it is unlikely to be able to go much further back than a few generations before Charlemagne. I do not believe it is possible to document descent from Roman emperors at this time. | [
"The tree is largely based on the late 9th-century \"Anglo-Saxon Chronicle\", the West Saxon Genealogical Regnal List (reproduced in several forms, including as a preface to the [B] manuscript of the Chronicle), and Asser's \"Life of King Alfred\". These sources are all closely related and were compiled at a simila... |
why aren't car insurance companies legally restrained from only offering exorbitant rates? | There is no clear factual answer to this question, but the bottom line is that various state legislatures have declined to impose such requirements. This could be because of corporate influence, it could be because of a belief that free market competition will guarantee good service. Regardless of the reason, legislators merely did not enact that policy. | [
"Most insurers around the world have introduced some form of merit-rating in automobile third party liability insurance. Such systems penalize at-fault accidents by premium surcharges and reward claim-free years by discounts, commonly known as a \"no-claims discount\".\n",
"High risk drivers are often undesirable... |
why do artificially made things cost less than natural things? | It comes down to economies of scale. It’s cheaper to make a thousand gallons of apple- scented sugar water than it is to find enough good apples, transport them to a juicing facility, process them into juice, transport the juice to the point of sale, and also have to clean up the juicer machinery and deal with the detritus left from the juicing. The current system is what makes the most money for the rich men who own the resources and means of production at the expense of us poor shmucks who try and sell our labor to get access to basic goods and services. | [
"However, artificiality does not necessarily have a negative connotation, as it may also reflect the ability of humans to replicate forms or functions arising in nature, as with an artificial heart or artificial intelligence. Political scientist and artificial intelligence expert Herbert A. Simon observes that \"so... |
What would cause a pint glass to spontaneously combust? | That didn't spontaneously combust, it just shattered. Glass does that when it is heated or cooled unevenly. If you wanted to, you could repeat it by gently heating another pint glass to the boiling temprature of water, then dipping one end of it in ice water. The cold end shrinks, creating internal stress, because the other end is still expanded. The strain is releived by violent shattering. If you do it, wear gloves, goggles, condom, etc.
Hard to say why it happend to the pint glass, but it probably had an imperfection that made it vulnerable. It may not have been annealed properly at the factory, it could have been carrying internal stress from the manufacturing process for years. | [
"The irregular glass wafers, called \"fractures\", are prepared from very hot, colored molten glass, gathered at the end of a blowpipe. A large bubble is forcefully blown until the walls of the bubble rapidly stretch, cool and harden. The resulting glass bubble has paper-thin walls and is immediately shattered into... |
if the earth "wobbles" as it spins and orbits the sun, what prevents it from spinning out of control? | INTERESTINGLY, Hyperion, due its unusual shape and geology; its resonance with Titan; and dynamical flattening effects from many objects in the Saturn system, DOES spin out of control. Wooooooo | [
"In graphical terms, the Earth behaves like a spinning top, and tops tend to wobble as they spin. The spin of the Earth is its daily (diurnal) rotation. The spinning Earth slowly wobbles over a period slightly less than 26,000 years. From our perspective on Earth, the stars are ever so slightly 'moving' from west t... |
Why was flanking a larger force (such as during the Battle of Cannae) so effective? Wouldn't the smaller force be worn out by the larger one even if they did encircle them? | In ancient battles, on the whole, the heavy infantry of the main battle line was very much focused on the fight in front of them. The anticipation of having to engage in close combat was mortifying, and the business at hand required their complete attention. In addition, given the minimal technological means of conveying orders, ancient generals rarely issued new orders after the battle had begun, relying on their men to carry out the task that their deployment set before them.
As a result, when an enemy force suddenly appeared in their flank or rear, they got confused easily, since they no longer knew what was going on; morale would collapse quickly, and men would scramble to take advantage of whichever way out was left to them. If the encirclement was complete, as at Cannae, panic and chaos would soon destroy any remaining capacity of the encircled army to resist.
Good discipline and effective local leadership were decent remedies; veteran Roman armies like that of Caesar were generally able to respond well to being outflanked. Greek hoplites, on the other hand, were much less well-trained than Roman legionaries, and their behaviour in battle was correspondingly fickle. There are many examples of entire armies routing when an enemy force appeared in the flank or rear of the phalanx. It needn't even be a large force. At the battle of Delion, the Thebans sent 200 cavalry to save their crumbling left wing; the Athenians, thinking a whole fresh army had come up to reinforce their enemies, promptly fled. | [
"As the two phalanxes closed for battle, both shifted to the right. (This was a common occurrence in hoplite battles—hoplites carried their shield on their left arm, so men would shift to the right to gain the protection of their neighbor's shield as well as their own.) This shift meant that, by the time the armies... |
How can one locate the records of a deceased Red Army soldier in WWII? | There's online database "Memorial" of all USSR citizens, who served in Soviet Army and who were killed or missed in action during WWII.
It is in russian and you would need to enter your grandpa names in russian in order to search.
Several caveats:
* some russian and ukranian frequent first/last name combination may generate huge lists - e.g. *Иван Петров*
* many casualty reports were written in haste and spelling of rare names or those with non-trivial spelling might be different from other official papers. If you don't find direct hit, try to modify - for example, *Авксентий ~ Авсентий ~ Овсентий*.
* it is very helpful to know exact date and place of draft, date of birth (again, some reports might misstate those, so look for similar too), which unit he served, rank etc.
* it is ~80% complete (last time I've heard) and there are many white spots - especially from 1941 and 1942, from encircled units with all documents lost etc. The goal is to have it as complete as possible and expand it beyond WWII.
[**OBD Memorial**](_URL_0_)
If you need any help - please contact me.
| [
"In the post-war era the military search service Deutsche Dienststelle (WASt) has been responsible for providing information for the families of those military personnel who were killed or went missing in the war. They maintain the files of over 18 million men who served in the war. By the end of 1954, they had ide... |
How much do we actually know about the seafloor | We have very detailed [bathymetric](_URL_3_) maps of a lot of the ocean (e.g. _URL_0_). But that's only like having a topographic map of land - it doesn't tell you what's on it, but is fairly easy to do via remote sensing (e.g. sonar, etc).
We have actually explored the sea floor fairly well. Remote submersibles can be used to take images and samples of the floor. Obviously shallower seafloors (i.e. those on continental shelves) are more well explored than the deep ocean, but it's important to remember that the really deep places like the Mariana trench and Challenger deep are pretty rare and most of the deep ocean isn't as deep as them.
So, what have we found? Well actually most of the seafloor is pretty bare and sparse. There are areas of increased habitation (most around [seamounts](_URL_4_), but mostly it's just deposited crud that has dropped out from shallower water.
The big thing we haven't really explored is not the *bottom* of the ocean, but the *ocean* itself. The volume of the oceans is several [*billion* cubic *kilometres*](_URL_2_). We have examples of washed up carcasses of species that have *never been seen* in the wild. The majority of the ocean between the floor and surface is incredibly badly explored - I saw an interesting talk last week along those lines, there's an open access paper available here _URL_1_.
So that's the case in terms of life, I couldn't really speak to the other aspects of exploration you might be asking about. | [
"These data suggest human occupation when the sea level was lower than present, and that submerged archaeological sites could occur along the paleocoastline beyond the current shorelines of Haida Gwaii (Fedje & Christensen, 1999) and Southeast Alaska.\n",
"Apart from sediments the expedition looked at biology. Th... |
what is a delegate (presidential race)? | You are correct delegates are points, but they are people. In June / July all the delegates will assemble at the party conventions and formally cast their votes for presidential nominee. The primaries and caucuses say how many of a states delegates will vote for you on first ballot. Win 50% + 1 delegate votes and you become the official candidate for the November election.
But who actually serves as delegate varies widely by state. Some states allow candidates to pick, some allow party chairman or governor to pick, some even have you get elected from each individual county on up. | [
"In the modern U.S. presidential election process, voters participating in the presidential primaries are actually helping to select many of the delegates to these conventions, who then in turn are pledged to help a specific presidential candidate get nominated. Other delegates to these conventions include politica... |
why aren't there massive lakes of water floating around in space? | There are, but they are giant balls of ice | [
"Because of its high salt concentration, the lake water is unusually dense, and most people can float more easily than in other bodies of water, particularly in Gunnison Bay, the saltier north arm of the lake.\n",
"BULLET::::2. The Water Water is described as being exterior to the sphere of the Earth and interior... |
let’s say i wake up before my alarm 10 minutes early, and i decide to sneak in extra sleep. i either go back to sleep which feels like an hour when in reality only 5 minutes has passed or i sleep which feels like 5 mins when actually an hour has passed. why does this occur? | There are different stages of sleep: stage 1, 2, 3, 4, and REM. If you wake up during REM (the dreaming stage basically), your body releases a chemical that prevents you from moving, and it might not have been fully removed yet.
If you don’t fully wake up i.e. hit snooze and immediately close your eyes again, you can jump back to REM and even resume your dream.
My guess is that if you woke up feeling like crap, and tried to sneak in extra sleep, you’ll probably still feel like crap because you’ll still be waking up from REM. If you woke up feeling meh, and snuck in extra sleep, you’ll wake up from a lighter stage of sleep and not feel like crap.
From experience though, your state of mind before going to sleep is a big factor, even bigger than that REM stuff, and I don’t know how it works, but it kinda makes sense evolutionarily that if you’re on alert for something, your body is more prepared to spring into action.
Edit: I’ve been informed that REM isn’t considered deep sleep | [
"A common false awakening is a \"late for work\" scenario. A person may \"wake up\" in a typical room, with most things looking normal, and realize he or she overslept and missed the start time at work or school. Clocks, if found in the dream, will show time indicating that fact. The resulting panic is often strong... |
what is an arduino micro controller? ive seen a lot of posts about people doing awesome stuff with them. but i haven't been able to get a straight answer for just what it actually is | It's basically a circuit board and small CPU. I don't /think/ it has a proper operating system, but it does have a programming language attached. Connect some other electronic parts to it and come up with the program, and you have an arbitrary electronics device.
IE; attach it, a microphone, a small motor, and some wheels to a frame, and did some pretty decent programming, you could make a toy car that started and stopped when you clapped or said a word.
Most people that are willing to buy them probably do cooler things than that. | [
"The micro-controller simulation in Proteus works by applying either a hex file or a debug file to the microcontroller part on the schematic. It is then co-simulated along with any analog and digital electronics connected to it. This enables its use in a broad spectrum of project prototyping in areas such as motor ... |
Who first thought of stairs? | hi! if you don't get answers here, this question might be worth x-posting to an archaeology sub, or /r/AskAnthropology | [
"It is believed the stairs were built some time before the rule of Tiberius (14–37), as they were not mentioned by name in any ancient texts that predate this period. Their first use as a place of execution is primarily associated with the paranoid excesses of Tiberius' later reign.\n",
"The staircase design had ... |
Why do we see meteor showers some specific days only? | There are various asteroid "clouds" in our neighbourhood, but their orbit around the sun only intersects with our orbit around the sun every now and then. When the orbit of an asteroid cloud intersects that of the Earth, we can see a meteor shower. On other days, there are simply little to no meteors of sufficient size entering and burning up in our atmosphere. | [
"The shower is visible from mid-July each year, with the peak in activity between 9 and 14 August, depending on the particular location of the stream. During the peak, the rate of meteors reaches 60 or more per hour. They can be seen all across the sky; however, because of the shower's radiant in the constellation ... |
assassins creed story arc with the apple and pieces of eden. | A guy over on /r/assassinscreed recently posted a couple of excellent synopses for all of the games. Warning: they do contain NSFW language - or language not suitable for 5 year olds!
[Assassin's Creed 1](_URL_0_)
[Assassin's Creed 2](_URL_2_)
[Assassin's Creed: Brotherhood](_URL_1_)
[Assassin's Creed: Revelations](_URL_3_) | [
"To drive the story, the team had to come up with some goal that both the Assassins and Templars were searching for. Philippe Morin had suggested using the apple of Eden, which the team initially thought to be a humorous aspect for everyone fighting over an apple. However, as they researched into the game more, the... |
What does stingray venom do? | > Stingrays have a spine at the base of their tail that contains a venom gland. The spine, including the venom gland, may be broken off in the attack and may remain in the wound. The venom has vasoconstrictive properties that can lead to cyanosis and necrosis, with poor wound healing and infection. Symptoms include immediate and intense pain, salivation, nausea, vomiting, diarrhea, muscle cramps, dyspnea, seizures, headaches, and cardiac arrhythmias. Fatalities are rare and usually a consequence of exsanguination at the scene or penetration of a vital organ.
[source](_URL_0_)
> The venom contained within the glands in all species is heat labile. A variety of proteins, enzymes, and serotonergic and cholinergic substances have been identified as components of the venom, but the exact component responsible for the severe symptoms and pain is yet to be isolated.
[source](_URL_1_) | [
"The venom of the stingray has been relatively unstudied due to the mixture of venomous tissue secretions cells and mucous membrane cell products that occurs upon secretion from the spinal blade. Stingrays can have anywhere between one and three blades. The spine is covered with the epidermal skin layer. During sec... |
Why is it that some nations within the Soviet Union (Ukraine, Georgia, etc.) received the status of SSR while others (Karelia, Chechen, etc.) were only ASSRs? | It was a perilous issue in the early years of the USSR, and mainly had to do with population and territorial size as well as loyalty to the regime (though in the case of the Baltics, Stalin made each an SSR to characterize themselves as liberators to the rest of the world). Making Chechnya a full-fledged Republic would have been rather politically taboo post-Stalin as well given he deported so much of the population and only many years later were they allowed to return to their homes. Karelia was briefly an SSR after the Winter War, but post-war when Finnish-Soviet relations improved it was downgraded in status.
Under Stalin in general SSR status was given rather inconsistently, particularly in the Caucuses where he separated, merged, and re-separated many nations into various SSR's. Perhaps the best known example was Georgia, which had the Abkazhian region broken off by Stalin and upgraded to the Soviet Socialist Republic of Abkazhia. This was mainly done because the oft-difficult relationship between the Georgians and the Kremlin, and because Stalin had close personal ties to Abkazhian party boss Lakoba. However when Lakoba had a falling out with Stalin in the early 1930's, Abkazhia was "downgraded" to an Autonomous Soviet Socialist Republic.
After Stalin however, the administrative organization of the USSR remained much more stable. | [
"All of the former Republics of the Union are now independent countries, with ten of them (all except the Baltic states, Georgia and Ukraine) being very loosely organized under the heading of the Commonwealth of Independent States. However, most of the international community did not consider the Baltic countries (... |
what is the difference between shaving using a trimming machine , a razor or waxing besides the physical method and why is one preferred over the other | A trimmer leaves the hair partially there and is merely cutting it down to a certain length. You use this when you want to keep your beard but groom it, and trimmers are often used when doing normal haircuts for the areas that are going to be relatively short.
A razor cuts much closer, shaving off almost all of the exposed hair and leaving skin that looks smooth.
Waxing coats the skin and solidifies, binding the wax to the exposed hair. Placing a sticky strip on the wax and quickly removing it then rips the hair out of the follicle down to the root, resulting in a lack of hair until it can grow from the root again, which should last 1-6 weeks or so depending on the person. | [
"The shaving process is a finishing operation where a small amount of metal is sheared away from an already blanked part. Its main purpose is to obtain better dimensional accuracy, but secondary purposes include squaring the edge and smoothing the edge. Blanked parts can be shaved to an accuracy of up to 0.025 mm (... |
Did the Kingdom of Saxony intend to conquer some or all of Austrian Silesia prior to the annexation of the latter by the Kingdom of Prussia? | There wasn't a kingdom of Saxony before the annexation of Silesia by the Kingdom of Prussia. | [
"In 1813 the Kingdom of Prussia occupied large amounts of Saxony's territory in the Battle of Leipzig, including the Electoral Circle (which had been renamed the \"Wittenberg Circle\" in 1807); in May 1815 a treaty was signed in which Saxony ceded this territory to Prussia. In June 1815 they all became part of the ... |
advances in (metal) armor thourgh the centuries | This is an important question in the history of armour. In fact, this is a huge question, and there's a lot to say about it.
I will start off with some historiography. The early historiography of armour is saw medieval armour's development as being like that of early 20th century battleships, or 20th century tanks - more powerful weapons necessitated better armour. In this telling, plate armour is a response to the crossbow and the longbow and to various staff weapons. Speaking abstractly, this is a demand-side explanation for the development of plate armour - plate armour develops because soldiers need it. But the chronology of this development does not quite make sense - crossbows appear in the 12th century or earlier, and plate armour does not really take off until the 14th century (after getting its start in the 13th). Moreover, some attacks, like a blow from a mounted soldier's couched lance, are at least as strong as bow-shots, and couched lances have been around for centuries before plate armour is developed. Now, some armour (especially later in the history of plate armour) appear to be responses to more powerful weapons, so we should not discount this demand-side explanation, but it is not the whole story.
Alan Williams in *The Knight and the Blast Furnace* looked at the bloomeries and blast furnaces that produced medieval iron and steel to provide a supply-side explanation for plate armour's origins. He looked at the size of excavated blooms and found that they greatly increase in the later Middle ages. This is important because armour cannot be welded from multiple pieces-each plate of a set of plate armour must be made from a single piece of steel (otherwise the armour is weak where it is welded). Big plates like breastplates must be made from big pieces of steel. This is a contrast to mail or scale armour, which can be made from small pieces of steel or iron (hence why societies with even small bloomeries can make these types of armour).
This all means that armours made of large (ish) solid places of metal need to start with large blooms of iron or steel in the bloomery. And there is a strong correlation between the increase in bloom size and the size of armour plates - from the introduction of one-piece breastplates to the profusion of single-piece helmet skulls, over the course of the 14th and into the 15th century the general trend is for the big plates of armour to get bigger. So bloom size (which is in turn the result of larger bloomeries) is an important precondition for the development of plate armour.
The other thing that bigger, more efficient bloomeries and blast furnaces do is make steel and iron cheaper. This causes a profusion of plate armour in various forms across different classes of soldier, until in the 16th century mass-produced 'munition armour' is arming the soldiers of the Early Modern monarchs. Blast furnaces which melt iron and produce pig iron (an iron/carbon alloy with a carbon content higher than steel) are cheaper and more efficient than bloomeries, which further reduces costs. However, pig iron must be 'fined' in order to be forged - it must have its carbon content reduced in order to make it less brittle. This process generally reduced armour's carbon content to little or nothing, which reduced the quality of the armour. This is particularly important because only medium and high-carbon steel can be hardened by heat treatment - 'quenching' hot steel in water to change its crystalline structure. So in the 16th century armour gets cheaper, but in some ways its metallurgy declines.
There are other technological developments important in the history of armour in the later middle ages. Water-powered trip hammers were used to beat blooms into sheets of steel, which would then be sold to armourers both locally and abroad. Water-powered polishing mills reduced the labor required to polish armour, which was the most laborious and tedious part of making armour. Both of these developments help encourage the spread of plate armour, or at least lowered its cost. But these cannot be taken outside of the larger social context of an increasingly urbanized and organized economy. Making plate armour required sophisticated workshop and guild organizations to divide labor, acquire and use capital and to maintain quality. This social context (which depends upon strong civil government and a codified system of contracts, among other things) is a necessarily precondition of technological developments like hammer-mills and polishing wheels - in many cases, these mills were funded by guilds or other craft organizations, or owned by proto-capitalist merchant-armourers like the Missaglia.
So plate armour was the product of all these things - larger blooms of steel, water-powered hammer and polishing mills, and more sophisticated social and economic organizations that could support the very sophisticated armouring industry. But we can't forget about the other side of the equation, the soldiers wearing the armour and their needs. As Tobias Capwell has argued, armour is adapted to the way that the people wearing it fight. English armours from the 15th century are meant for fighting on foot, while Italian armours of the same period are meant for fighting on horseback. This is reflected in the form of the armour. At the same time some features of armour - the neckline, the waistline, the shape of the sabbaton and more - are products of fashion.
When we see an armour in a museum what we're seeing is the product of all of this - technological developments, ways of war, economic organization and fashion.
If you are interested in learning more about the metallurgy and manufacture of armour, you may be interested in some of my previous answers:
* [Manufacturing and Supplying the Armour of Weapons of a Late Medieval Army](_URL_2_)
* [From Ore to Harness: The Steps of Manufacturing Plate Armour](_URL_3_)
* [The Importance and Illusiveness of 'Good Steel' in Medieval and Early Modern Armour](_URL_4_)
* [Why were Milanese armourers so successful?](_URL_5_)
* [The Armour Industry of Milan, contd.](_URL_1_)
* [Manufacturing Munition Armour](_URL_0_)
| [
"Armour has been used throughout recorded history. It has been made from a variety of materials, beginning with the use of leathers or fabrics as protection and evolving through mail and metal plate into today's modern composites. For much of military history the manufacture of metal personal armour has dominated t... |
How do we simultaneously know how far away a stellar object is *and* its chemical makeup? | each element has a unique set of spectral lines it leaves. We look at all the spectral lines of the star and are able to determine its makeup. Redshifting merely shifts all of these values uniformly toward the red end of the spectrum. But the spacing between the lines remains the same.
edit: analogy. Imagine I have a barcode sitting in front of me. Now I move the barcode an inch to the left. I can still read it, it's just shifted now. | [
"In addition to being far away, many stars of such extreme mass are surrounded by clouds of outflowing gas created by powerful stellar winds; the surrounding gas interferes with the already difficult-to-obtain measurements of stellar temperatures and brightnesses and greatly complicates the issue of estimating inte... |
Does the body prevent inhalation of the lungs when a person is knocked out and under water? | In lifesaving you learn that the body keeps breathing and so an unconscious submerged person will drown choking on water - though I'm not sure they keep inhaling after the that initial gulp of water.
An interesting aside, the difference between a Personal Flotation Device or PFD (vest type) and a true Lifejacket is that the latter will flip an unconscious person onto their back so they don't drown. The boring old key-hole type jackets are designed to provide flotation that supports your head and keeps your chest up. In this way they're unbeatable. | [
"If the breathing gas in a diver's lungs cannot freely escape during an ascent, the lungs may be expanded beyond their compliance, and the lung tissues may rupture, causing pulmonary barotrauma (PBT). The gas may then enter the arterial circulation producing arterial gas embolism (AGE), with effects similar to seve... |
If Black Holes have supposedly infinite density and gravity has infinite range why is the entire universe not pulled into it? | Infinite density does not mean infinite mass, so as your mass is still some finite value, it behaves similarly to a gravitational point source.
For example, if the Sun turned into a blackhole right now, I would only notice 8 minutes later when it suddenly looked like someone decided to turn off daylight, otherwise we'd happily continue to orbit it just fine.
Also while the singularity may have "infinite" density the black hole itself could be thought of as having a density (BH_Mass/BH_volume)
| [
"Gravitational collapse requires great density. In the current epoch of the universe these high densities are only found in stars, but in the early universe shortly after the Big Bang densities were much greater, possibly allowing for the creation of black holes. High density alone is not enough to allow black hole... |
How can a body accept an organ from a different person if they have different DNA? | Immune recognition of self vs non-self is a pretty complicated thing. Different organs and different protocols require different degrees of matching. For solid organs, you can get by with matching by the major blood ground antigen. For bone marrow, you need more.
Invariably, left untreated (barring autotransplantation or a kidney from an identical twin or something), there is always some rejection as there is always some degree of mismatch. Managing this is a key technique in transplant medicine. The general technique is to turn down the immune system. This starts during the operation, usually with big-gun anti lymphocyte (a type of white blood cell, consisting of T and B cells) medicines. The mainstays of solid organ immune suppression is steroids and other anti-T-lymphocyte drugs like cyclosporine (which revolutionized transplant medicine), or other newer drugs. When you turn down T-cells, you become more prone for certain infections, so post-transplant patients are often given antibiotics and antivirals to prevent these.
All organ transplant patients have regular assessments of rejection. In bone marrow, this may be monitoring blood counts and graft-versus host disease. In lungs, CT and bronchoscopy are used as well as pulmonary function testing. Liver and kidney are usually tested by serum chemistries and biopsies if necessary. In the heart, they may do endomyocardial biopsies and catheterizations. Certain things like infection or alterations of medicine may lead to a flare of rejection. In these circumstances, the usual action is to turn up the immune suppression. | [
"Organ transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transported from a donor site to another location. Organs and/or tissues that a... |
why is eating too much after a long period of starvation dangerous? | This is an extremely difficult to answer question in a manner for a 5 year old to understand because it requires a basic biochemistry background to understand but here it goes:
In starvation mode your body is conserving energy. It takes a little energy to digest food and get things going. To make this energy your need the elements potassium, phosphorous and magnesium (how and why is beyond the scope of this question)
Since you have starved, your body's supply of potassium, magnesium and phosphorous are low and are supplying energy to the necessary functions of your body for survival. When you eat, the demand for energy increases to the point where your body cannot produce the necessary energy to digest the food (you lack the 3 key elements in sufficient quantities). Your blood levels of potassium, magnesium and phosphorous go into dangerously low levels that cause cardiac arrest, irreversible neurological problems (because your body's reserves of those elements gets immediately depleted while your gut tries to make the digestive acids, bile, energy for movement through the GI tract). This is **"refeeding syndrome"**
Hope this helps | [
"Victims of starvation are often too weak to sense thirst, and therefore become dehydrated. All movements become painful due to muscle atrophy and dry, cracked skin that is caused by severe dehydration. With a weakened body, diseases are commonplace. Fungi, for example, often grow under the esophagus, making swallo... |
why do audience members at a sitcom filming laugh at everything? | A) If you're at the taping of a show, chances are you're already a fan of it, which means you'll be more likely to laugh. The excitement of actually being there probably plays into this as well. I know I'd be pretty giddy if I got to go to a Seinfeld taping or some such.
B) People are much more likely to laugh when in a group of other people who are laughing. It ends up feeding into each other.
C) They actually bring out stand up comedians to warm up the audience as well as keep them entertained between scenes.
D) They milk it in post a bit. | [
"Audience reactions were live, thus creating a far more authentic laugh than the canned laughter used on most filmed sitcoms of the time. Regular audience members were sometimes heard from episode to episode, and Arnaz's distinctive laugh could be heard in the background during scenes in which he did not perform, a... |
Were swords/bows/etc.. controlled from general masses in any given periods? | FYI, you'll find a few examples in the FAQ to get you started
* [Gun (and other weapons) control](_URL_0_) | [
"In the 19th century, simple cross-hilt small swords were also produced, largely as ceremonial weapons that were evocative of more ancient types of weapons. An example is the Model 1840 Army Noncommissioned Officers' Sword, which is still used by the United States Army on ceremonial occasions. As the wearing of swo... |
Would someone be able to make a flashlight like device that used light out of the visible spectrum? | Were you describing an [active infrared night vision system](_URL_0_)? | [
"A variety of light sources can be used, ranging from simple flashlights to dedicated devices like the Hosemaster, which uses a fiber optic light pen. Other sources of light including candles, matches, fireworks, lighter flints, steel wool, glowsticks, and poi are also popular.\n",
"An electric eye is a photodete... |
Is it possible for junk foods to make your body gain more weight than the actual weight of the food itself? If so, how does this happen? | So you're getting two different sets of answers based on two different readings of your questions.
First, conservation of mass is a thing. Re-arranging molecules won't let you get a higher mass. Even fixing gasses probably won't get you there, because you are expending energy in the process of re-arrangement.
Second, conservation of volume is not a thing. You could easily eat a small portion of energy dense food and add more volume than that to your body structure. | [
"When junk food is consumed very often, the excess fat, simple carbohydrates, and processed sugar found in junk food contributes to an increased risk of obesity, cardiovascular disease, and many other chronic health conditions. A case study on consumption of fast foods in Ghana suggested a direct correlation betwee... |
how come that when you go to bed at 11pm you have a hard time to leave your bed at 7am, but when you go to bed at 3am you dont have any problems waking up at 11am while you had the same hours of sleep? | Might be a number of things.
1) You aren't used to waking up early, so your body isn't ready for it. If you don't usually wake up at 7am and then suddenly do, it'll be hard.
2) It's often colder in the morning, especially in the winter. Getting out of bed in the cold is hard.
3) It's much brighter at 11am than 7am and our body responds to sunlight. This is why we get tired at night, because your body release melatonin to help get ready for sleep. | [
"Affected people often report that while they do not get to sleep until the early morning, they do fall asleep around the same time every day. Unless they have another sleep disorder such as sleep apnea in addition to DSPD, patients can sleep well and have a normal need for sleep. However, they find it very difficu... |
What’s in the direct center of a black hole? When light and other various things get sucked into the black hole what happens to them? Are they crushed? What happens when something goes into a black hole? | Any particle that crosses the event horizon must move toward the singularity. We cannot predict what happens to the particle beyond that; our current theory does not have that capability. (Indeed, this is what it means for there to be a singularity.) | [
"The defining feature of a black hole is the appearance of an event horizon—a boundary in spacetime through which matter and light can only pass inward towards the mass of the black hole. Nothing, not even light, can escape from inside the event horizon. The event horizon is referred to as such because if an event ... |
why do different languages each have their own version of the same names? | Names begin as a single name in a parent language like Latin and will be spread throughout the geographical area where that language is spoken (in the case of Latin, most of Western Europe.) However, languages change gradually over time, with speakers slowly but surely changing the pronunciation rules of individual letters/sounds. The interesting thing about those changes is that they tend to occur consistently across the entire language, instead of in small pockets. The names end up being pronounced differently because the descendent languages have changed how they pronounce the original sounds of the name. Often spelling used to change to match pronunciation, which introduces another way for names to drift.
As far as names adopted from other languages: remember that languages do not share the same sounds as each other. Many languages employ sounds that speakers of other languages simply cannot say correctly. Thus, many names couldn’t be adopted directly even if the adoptive speakers wanted to do so.
As to the idea of “why don’t they keep it the same?” — that’s treating a language like it’s a conscious entity. It’s not: a language is simply the sum total of everyone who speaks it. If everyone hears a certain pronunciation, they will follow suit. There is no overarching control over how the language changes. | [
"Number names are rendered in the language of the country, but are similar everywhere due to shared etymology. Some languages, particularly in East Asia and South Asia, have large number naming systems that are different from both the long and short scales, for example the Indian numbering system.\n",
"Dual namin... |
How many individual bacteria/viruses does it take to infect you with a disease? | Each virus and bacterium has a different design, so some are more infectious than others. For example, the number of vibrio cholerae (which causes cholera) that you need to ingest to become infected is between 1,000 and 100,000,000, but the number of EHEC (a really wicked E. coli strain) that you need is closer to 10. [source](_URL_0_) | [
"Typically, the infection enters the body through a break in the skin such as a cut or burn. Risk factors include poor immune function such as from diabetes or cancer, obesity, alcoholism, intravenous drug use, and peripheral artery disease. It is not typically spread between people. The disease is classified into ... |
How long would it have taken for a civilian to travel from New York City to Madrid circa 1914? | From the 1870s to 1900 the White Star Line had a policy of seeing how fast they could do their Liverpool-New York line. The last record holder was the steam ship SS Teutonic in 1890, who reached New York harbour in 5 days, 16 hours and 31 minutes. In the 1900s White Star changed their policy to comfort over speed, so in 1903 the Teutonic took 6 1/2 days again, becoming the last company record holder.
For your 1910s range, we can take a look at the SS Finland. In early 1915 she made two consecutive journeys from Genoa to New York over several Mediterranean harbours. The first starting on February 6th, going over Naples (7th), Palermo (8th) and Gibraltar (12th) and arriving in New York on the 23rd of February. The second one started March 24th, went through Naples (25th), Messina (26th), Palermo (27th), Gibraltar (31st) and Fayal on the Azores (April 4th) and arrived in New York on April 11th.
So if we take Gibraltar as the nearest port the first trip took 11 days and the second one 12 with a stop. Assuming a train or car ride from Madrid to Gibraltar doesn't take more than a few hours you can probably fit the whole journey comfortably into 12 days. Maybe it's slowed down because of the war, but then the Finland's New York-Antwerpen runs the decade before also took about 9/10 days on average.
Sources:
[SS Teutonic schedule](_URL_1_)
[SS Finland schedule](_URL_0_) | [
"BULLET::::- 1939 24 May, owner Francisco Sarabia set a new record for a non-stop flight from Mexico City to New York City in 10 hours and 47 minutes. He also set records for flights between Los Angeles to Mexico City, Mexico to Chetumal, Mexico to Mérida and Mexico to Guatemala.\n",
"In 1939, a passenger traveli... |
Is sulphuric acid is stronger than hydrofluoric, why can HF acid dissolve glass? | The "strength" of an acid can be a bit of a misnomer, depending on what you are talking about.
"Strong," when discussing acids, is a measure of how completely that acid will be ionized in aqueous solution. In other words, a strong acid, like sulfuric acid (H*_2_*SO*_4_*) will "completely" dissociate in water:
H*_2_*SO*_4_* + H*_2_*O ⇌ HSO*_4_*^- + H*_3_*O^+
where "all" the H*_2_*SO*_4_* has broken apart. It's not absolute, and the actual amount that breaks apart is how we determine the "strength" of an acid. The mathematical representation of this is pH (i.e. how much "H" has come off of the acid).
For hydrofluoric acid (HF) the equilibrium expression is similar:
HF + H*_2_*O ⇌ F^- + H*_3_*O^+
except that in the case of HF, the amount of dissociation is much much smaller.
So now that we've established what a "strong" acid is, you can see that the strength of the acid really only will have an impact when you are comparing two reactions that involve the proton (H^+ or H*_3_*O^+ ) *as the primary/most important reactant.*
Assume that reactant A is highly reactive with H^+; the more H^+, the more reactive it is. In this case, the stronger acid, the one that dissociates into more H^+, will have a greater impact on reactant A.
But now if we assume that we are reacting with something else, say, glass. Silicon is a primary constituent of common glass. In an article in [Physical Review Letters 1990, 65, pp 504 - 507, Trucks et al.](_URL_0_) examine one mechanism of action for the etching of silicon glass by HF. This article is probably behind a paywall, but below is a snippet of a useful diagram.
[Here's a diagram.](_URL_1_)
As you can see, the HF comes in, and the F^- binds to the silicon. The leftover H^+ then takes the place of the bond that the F^- just cleaved and replaced. Do this three more times, and the silicon atom leaves as SiF*_4_*, leaving behind an etched surface.
In this case, the F^- binding to the silicon is crucial to the mechanism working, not the concentration of H^+ in the system. Thus, the HF does not have to be a strong acid to work its magic here. Since the sulfuric acid doesn't behave similarly and cleave that Si-H bond, it won't etch the glass!
Of course, this is only one study I found, and it's a few years old. Other chemists who use this on a more regular basis may be more familiar with other mechanisms of action. But I think this illustrates the point!
Edit: Formatting and some emphasis. | [
"Hydrofluoric acid and its anhydrous form, hydrogen fluoride, is also used in the production of fluorocarbons. Hydrofluoric acid has a variety of specialized applications, including its ability to dissolve glass.\n",
"Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. It is a precursor to almost ... |
How much of the universe's matter is in interstellar gases? | You mean ordinary matter? Because we still have no proper theory of quantifying dark matter. Excluding dark matter and energy, only one-tenth of ordinary matter is believed to be found in stars..so that means 9/10th of ordinary matter is dispersed in the interstellar medium.
EDIT: What I gave you above was a rough estimation of my previous knowledge that around 4.9% of all matter was ordinary matter _URL_1_ ...and that 0.5% of total mass of universe(when dark matter and dark energy was included) was contained in the stars .
EDIT2: Now to be exact...after seeing the referenced paper in the comments and some more research...My summary:
94.1 % of all ordinary matter in the observable is contained in the interstellar and intergalactic mediums, according to the "The Cosmic Energy Inventory": _URL_0_
The percentage of ordinary matter is divided as: stars = 5.9%, Interstellar Medium (ISM) = 1.7%, and Intergalactic Medium (IGM) = 92.4%. The total mass ordinary matter in observable universe is estimated to be 1.7 x 10^53 kg . Total mass of ordinary matter in all stars is roughly 10^52 kg. | [
"Interstellar matter, considered dense in an astronomical context, is at high vacuum by laboratory standards. Physicists showed in the 1920s that in gas at extremely low density, electrons can populate excited metastable energy levels in atoms and ions, which at higher densities are rapidly de-excited by collisions... |
If a humming bird is flying inside an airplane is the airplane heavier by the weight of the humming bird? | Yes. On a technical level, The hummingbird flies by accelerating air downwards, to produce an upwards force. This momentum will, even if it dissipates through all the air in the cabin, create a *slightly* higher pressure on the bottom of the cabin than the top. The difference on pressure, integrated over the inside of the cabin will equal the weight of the hummingbird. It will actually be higher or lower or could even be side to side depending on if the hummingbird is accelerating in a given direction. | [
"Hummingbirds have many skeletal and flight muscle adaptations which allow great agility in flight. Muscles make up 25–30% of their body weight, and they have long, blade-like wings that, unlike the wings of other birds, connect to the body only from the shoulder joint. This adaptation allows the wing to rotate alm... |
The primary cause of global warming is greenhouse gasses--but what about all of our waste heat? | Waste heat does have a local effect, but it is believed to account for only about 1% of anthropogenic forcing globally. Global forcing from waste heat was 0.028 W/m2 in 2005, while total anthropogenic forcing was about 2.9 W/m2 and net anthropogenic forcing was around 1.6 W/m2.
_URL_1_
_URL_0_ | [
"\"Global warming has been a great concern of many environmental scientists. Scientists believe that the greenhouse effect is responsible for global warming. Greatly increased amounts of heat-trapping gases have been generated since the Industrial Revolution. These gases, such as CO, CFC, and methane, accumulate in... |
how do sports leagues coordinate scheduling so many games without running into any conflicts? | a professor of mine in graduate school (he was an Operations Research guy), scheduled MLB games. Long story short, he ran a huge optimization program with constraints given to him by the league and the teams (i.e., need to be home these dates..no more than X consecutive games on the road, etc.). | [
"The schedule can also be used for \"asynchronous\" round-robin tournaments where all games take place at different times (for example, because there is only one venue). The games are played from left to right in each round, and from the first round to the last. When the number of competitors is even, this schedule... |
Did the culture of Carthage differ significantly from the culture of the older Phoenician city-states in the Levant? | According to Richard Miles' *Carthage Must Be Destroyed*, *Qart Hadasht*, or "New City" was mainly ~~Tyrrhenian~~ Tyrian in origin; this follows both the foundation myth of the city and the preeminence of Melqart and Estarte, the chief city gods of Tyre, in Carthage. Tyre was conquered by Hammurabi of Babylon in 572 BCE, and its trade with modern Spain and Italy became less and less lucrative; it's cultural influence waned and Carthage expanded both culturally and economically, in pursuit of trade and raw resources. Unlike the Canaanites, Carthage needed colonies not just for the wealth that comes with trade, but to acquire enough food and raw materials to fuel its large manufacturing sector. "Punic" - what historians now Carthage's language- was a dialect of Canaanite that all Pheonicians (who called themselves the *Can'nai*) spoke in different forms; Punic became the dominant language of trade in the Western Mediterranean.
Carthage would change it's Pheonician cultural beliefs in some ways while holding on to other aspects. For example, burial became the main funerary rite (as opposed to cremation), but Carthage held on the the sacrifice of elite children by cremation long after *tophet* sacrifice disappeared in the East. Carthage also had a form of constitutional government with various levels of citizenship for natives, foreigners and slaves. Oligarchs held true executive (financial and military) power, but there was a legislative Council of Elders and an institution of a Popular Assembly present during decision making sessions and with the ability to, at least as time, appoint generals (Miles clearly states that it had little relative power and did not represent a true democratic vehicle).
Greek influence molded Carthaginian culture on islands like Sardinia and Sicily and would make its way back to the city as well. Heracles became conflated with Melqart in a distinct syncretic religion, and Carthaginian sarcophogi adopted Greek statuary. From Miles:
> The emergence of what we might term a "Punic World" was not a linear progression from the old Pheonician one, but a complex and multifarious series of hybridizations with other indigenous and colonial cultures throughout the Western Mediterranean.
| [
"Carthage was one of a number of Phoenician settlements in the western Mediterranean that were created to facilitate trade from the cities of Sidon, Tyre and others from Phoenicia, which was situated in the coast of what is now Lebanon. In the 10th century BC, the eastern Mediterranean shore was inhabited by variou... |
why do symptoms of the common cold change as your body gets over them? | Basically the beginning is the foreign bodies attacking your cells and vice versa, damaging the near by tissue (pain). The ending is the left over waste products remaining inside your body from the fight and your body finding methods to move them from essential functioning areas or just expelling them. | [
"The common cold, also known simply as a cold, is a viral infectious disease of the upper respiratory tract that primarily affects the nose. The throat, sinuses, and larynx may also be affected. Signs and symptoms may appear less than two days after exposure to the virus. These may include coughing, sore throat, ru... |
why are "pretty" plants and flowers much less resistant than weeds and ugly small wild flowers? | Pretty garden plants are often a long way from home, so they're exposed to a variety of pests and diseases they wouldn't have much resistance to.
Weeds are generally local, or of they're incomers they're successful ones which have already shown they can cope with the local ecosystem.
The other thing is that garden plants are often some distance from their natural roots, (yea, awful) and may have traded strength and resistance for glamour. That's OK because in a garden we can protect them. | [
"Some of the species, notably \"Calystegia sepium\" and \"C. silvatica\", are problematic weeds, which can swamp other more valuable plants by climbing over them, but some are also deliberately grown for their attractive flowers.\n",
"Roses (\"Rosa\" species) are susceptible to a number of pests, diseases and dis... |
I need help identifying this disorder. | There are many things that could cause stunted growth. If you have more information that might be helpful, but I'm not confident that an accurate call can be made here. | [
"This is a list of major and frequently observed neurological disorders (e.g., Alzheimer's disease), symptoms (e.g., back pain), signs (e.g., aphasia) and syndromes (e.g., Aicardi syndrome). There is disagreement over the definitions and criteria used to delineate various disorders and whether some of these conditi... |
Do ticks or other blood sucking bugs (mosquitoes, etc) show preference to certain people? | Yes.
Both ticks and mosquitoes tend to target people by detecting the CO2 they release from their bodies, so perhaps your metabolic rate is higher than average and produces more carbon dioxide. Blood type O is preferred over A and B for them as well. Additionally, it could be that you were walking in front of them and picking up more because you were leading the trail. | [
"Some species are blood suckers rather than predators, and they are accordingly far less welcome to humans. \"Triatoma\" species and other members of the subfamily Triatominae, such as \"Rhodnius\" species, \"Panstrongylus megistus\", and \"Paratriatoma hirsuta\", are known as kissing bugs, because they tend to bit... |
Why didn't the straight-pull bolt catch on in military service? | I can speak as to the difficulties encountered with the Ross Rifle, which was a Canadian, straight-pull bolt action rifle used at the start of WWI by the CEF:
The Ross was an incredibly accurate rifle, and was a fantastic hunting weapon, but the realities of trench warfare meant that the unreliability of the action became an issue. When it became dirty or muddy, the Ross would misfire and the bolt - which had nothing to prevent it from flying backward - would oftentimes cause horrific injuries to the rifleman using it. The Lee-Enfield, on the other hand, was a far more rugged and reliable rifle, and was quickly adopted by CEF units. The Ross was still used by some CEF snipers who preferred the higher accuracy of the weapon, as they generally were able to take better care of their weapons then soldiers whose duties saw them constantly in the mud and muck of the trenches.
Mark Zuhelke's *Brave Battalion*, and Pierre Berton's *Marching to War* are both good popular histories of the Canadian Expeditionary Force in WWI, and both have sections dealing with the problematic nature of the Ross. | [
"The operating principle of the straight pull bolt action comprises a bolt \"sleeve\" to which the bolt lever or handle is attached. The sleeve is hollow and has spiral grooves or \"teeth\" cut into its inner surface in which slide corresponding projections or \"teeth\" on the outside of the bolt head or \"body\". ... |
How does photon-photon interaction not misconstrue the paths of other photon-photon interactions throughout space? | The short answer is that to a very good approximation photons simply don't interact with each other. To frame it a bit more technically, we would say that the [photon-photon scattering cross-section](_URL_3_) is extremely, extremely small. In other words, the photons of two crossing laser beams will quite literally just fly through each other.
This picture may seem at odds with the fact that light experiences interference, but in reality there is no contradiction here. All that interference means is that when two waves cross in space, their associated fields can add up [constructively or destructively](_URL_0_) so that the total field will have peaks and troughs that we can see (or measure). But it's important to realize that this interference doesn't actually change the incoming waves themselves. To see what I mean, let's go back to the example of the crossing laser beams. Let's say we have two beams where we have perfect control of the phase and we let them [cross at an angle](_URL_1_). In the region where the beams overlap in space, you will get an interference pattern, just as you expect. But this interference does nothing to the waves themselves and after the intersection the beams will just continue on their merry way as though nothing happened.
Just for the sake of completeness, if you go to sufficiently high energies, you will start to see some interactions between photons. With a very low probability two photons will sometimes smash together and create a particle-antiparticle pair in the process (an effect called [pair production](_URL_2_)). However for low intensity beams of low energy photons, this is an effect that you can very safely ignore. | [
"An intrinsic problem in using photons as information carriers is that photons hardly interact with each other. This potentially causes a scalability problem for LOQC, since nonlinear operations are hard to implement, which can increase the complexity of operators and hence can increase the resources required to re... |
How much oxygen does a candle use in a closed room? | Well first air is constantly diffusing in and out of the average room (via air ducts, cracks in doors/windows etc) so O2 is readily replaced. But for hilarity's sake lets assume we are in a perfectly sealed room or one where the air diffuses in more slowly than the candle would burn.
Its 1:30am here so please excuse stupid math errors feel free to correct any you see.
Math time:
Lets assume parafin wax with an average carbon chain length of 30. Now we have C30H62 as our molecular formula (mass 422g/mol).
Random googleing leads me to a burn rate of ~7hrs/oz or 15min/gram.
Now assuming complete combustion we have (i'll be embarrassed if i messed this up which is way too probable and apparently i did mess it up and fixed now):
2C30H62 + 91O2 -- > 60CO2 + 62H2O
Thus for every 2 moles of wax we burn 91 moles of O2.
Assume you sleep 8 hours thus 32grams of wax is burned (0.076mol) thus 3.4moles of O2 is burned.
At STP the air would be 22.4L/mol thus burning 77.5L. If you are in a "small" 3x3x2.5m room the total volume would be 22.5m^3 or 22500L. O2 is ~21% of the air so the partial volume the O2 would fill of that room would be 4725L.
In that 8 hr span where no air entered the room that single candle successfully burnt about 2% of the oxygen out of the air. That would roughly be the equivalent of being at 1500ft elevation from sea level. | [
"A \"chlorate candle\", or an \"oxygen candle\", is a cylindrical chemical oxygen generator that contains a mix of sodium chlorate and iron powder, which when ignited smolders at about , producing sodium chloride, iron oxide, and at a fixed rate about 6.5 man-hours of oxygen per kilogram of the mixture. The mixture... |
How many senses do we have, I have heard there is more than the five children get taught | Humans have more than five senses. Although definitions vary, the actual number ranges from 9 to more than 20. In addition to sight, smell, taste, touch, and hearing, which were the senses identified by Aristotle, humans can sense balance and acceleration (equilibrioception), pain (nociception), body and limb position (proprioception or kinesthetic sense), and relative temperature (thermoception). Other senses sometimes identified are the sense of time, itching, pressure, hunger, thirst, fullness of the stomach, need to urinate, need to defecate, and blood carbon dioxide levels. - Wikipedia | [
"Children are often taught five basic senses: seeing (i.e., vision), hearing (i.e., audition), tasting (i.e., gustation), smelling (i.e., olfaction), and touching. However, there are actually many more senses including vestibular sense, kinesthetic sense, sense of thirst, sense of hunger, and cutaneous sense.\n",
... |
We know that matter is transformed in energy inside stars. Is there anything else on the universe that does the opposite, where energy is converted to matter ? | There are a few possible answers to this. For instance, depending on how you define matter (note that there is no strict definition of what matter is), a black hole could be an example. Light that enters the event horizon contributes to the rest mass of the black hole, so energy becomes "matter".
But if you want to find cases of energy being converted into baryonic matter (e.g. atoms) you'll find it is pretty rare. Unless the density of energy is really high, converting energy into matter is associated with a decrease in entropy. So it won't happen spontaneously except for rare events.
These rare events can accumulate though. In stars, for instance, you mostly are fusing light elements to form heavier elements, and converting mass to energy along the way. You stop fusing once you form iron, which is the one of the lightest elements relative to the sum of its protons and neutron (i.e. highest [mass defect](_URL_1_)) and therefore one of the elements that has "lost" the most mass to energy. But some nuclei in the star continue to capture stray neutrons, forming heavier elements through the [S-process](_URL_3_). About half the atoms heavier than iron are formed this way. So there is a little bit of energy being converted into matter alongside the much larger conversion of matter to energy in a star. In a similar vein, we can create synthetic elements in reactors, spending lots of energy at once to convert a little of it into extra mass.
There are also some conditions where a lot of matter is generated all at once. As I alluded to earlier, if you raise the temperature enough you create energy so dense that forming matter is now associated with an increase in entropy. Supernova briefly reach temperatures where heavy elements are created rapidly, and this is the source of the other half of elements heavier than iron in the universe. We can create these high temperatures in very small volumes using particle colliders as well, so the LHC briefly creates a cloud of massive particles from the energetic collisions of nuclei. But the biggest example of energy being converted into matter is the Big Bang itself. In the [first second after the Big Bang](_URL_2_), most of the matter in the universe was formed.
If you want to keep track of all this, look at this [color-coded periodic table](_URL_0_). Besides the formation of protons and neutrons in the Big Bang, extra mass is only being created when elements heavier than nickel/iron are formed.
Finally, keep in mind that any system that absorbs energy gets a little more massive. Heating an object makes it more massive. Converting CO2 and water into sugars during photosynthesis creates a little extra mass. These changes in mass are so tiny we can't really measure them, but thanks to relativity we know the increase in mass is there. So technically "matter" is being created and destroyed in small amounts all around you right now. | [
"In cosmology and astronomy the phenomena of stars, nova, supernova, quasars and gamma-ray bursts are the universe's highest-output energy transformations of matter. All stellar phenomena (including solar activity) are driven by various kinds of energy transformations. Energy in such transformations is either from ... |
gold mines and supernovas | Most of the time is spent as dust in a cloud in the galaxy. It may form into bigger asteroids and small planets that may be ripped apart by a number of things. Eventually it arrives at the Earth. The reason gold is fond together in vanes is because similar materials with similar densities and other properties behave similarly and tend to end up in the same place. When the solar system were formed there were some sorting of the early asteroids based on density, and when the Earth were formed it was semi liquid so the heavy rocks got closer to the core then the lighter rocks. This is why there is so little gold on the surface of the Earth. Where there is gold is because of movement in the crust that pushes an area of gold up to the surface. | [
"Goldbug was next hired by the Maggia to steal some gold from an Empire State University laboratory. He did so, not realizing that the gold had been exposed to radiation during experiments at the university, and that he had thereby contracted radiation poisoning. He battled Spider-Man, but when Spider-Man revealed ... |
what happens to throwaway accounts? | I think many don't actually throw their account away, since their only reason for creating one is to keep their main account free of the association with what they're posting/saying on their throwaway account. Most aren't ducking the authorities or any real investigation.
To my knowledge, there's no "throwaway" flag that makes the account temporary, nor do I believe that reddit cleans user accounts after a period of inactivity. According to the FAQ in /r/help
> Please note that if your account is deleted, nobody can ever use that username again. Usernames cannot be recycled and accounts cannot be reopened.
So if they are just throwing their throwaways away and find they need another they would have to come up with a unique name for it.
Essentially, it's a throwaway account because they can throw it away if the account is subjected to large amounts of harassment, not because they're intended to be thrown away immediately after use. | [
"Another online method of cheating is \"multiaccounting\", where a player will register several accounts to his name (or, perhaps more commonly, to non-poker-playing friends and family members). This might be done to help enable the collusion previously mentioned, or perhaps to simply enable a well-known player to ... |
Least Expensive Firearms of the American Civil War? | For guns purchased in big numbers, rifled muskets were definitely cheaper, cheaper to supply with ammunition and more easy to service than breech loading guns ( which maybe is what you mean by "exotic"). According to the Ordnance Dept's statement of purchases from 1861-1866, certainly the few million mostly Austrian rifled muskets imported by Herman Boker & Co. for the US War Dept. were cheaper than the more standard Model 1855 or 1861 Springfield rifled muskets. Springfield was deep into its quest to produce guns with interchangeable parts, and it came at a cost: each Springfield cost the Ordnance Dept $19.52. The "Lorenz" rifled muskets were more varied in quality, fit and finish, and were around $13. I say, "around" because they first came with fixed simple sights that didn't allow change of elevation, and had to be reamed and rifled from .54 caliber to .58, if they were to take standard Springfield ammunition.... and I am not sure how and when all that was applied to the cost. One [auction house website says](_URL_0_) that the ones fitted with the improved Enfield leaf sights were $15: but I don't know their sources ( though some collector has no doubt done an exhaustive work on the history of Lorenz rifled muskets, I don't have it). But the more expensive Springfield musket , with more interchangeable parts, would have been easiest to service. If a Springfield needed a new lock, it could be simply screwed into place, while a new lock for a Lorenz ( assuming one was available) might first need some fitting by an armorer. That was, of course, the idea behind interchangeable parts.
Along with buying millions of Springfields and Lorenz muskets, the War Dept. discovered that, like buyers of cell phones and computers today, the best deals were for the stuff that was out of date. They also bought thousands of miscellaneous old guns, some already in the US and some that were being dumped out of foreign arsenals at good prices. The Prussians had been winning wars with their Dreyse needle guns, and so it was to be expected that they would sell 81,652 very obsolete " smoothbore muskets" to the US for just $6.80 each. The Model 1839 Potsdam musket was .72 caliber and could have used the same buck-and-ball loads that soldiers sometimes used in the .69 caliber Model 1842 Harper's Ferry musket. But I don't know who got them, and if they were happy to have them: the German and Austrian guns often came with beech instead of walnut stocks, which added some weight for the soldier to carry on his shoulder. And if that shoulder had been feeling the repeated recoil of a .69 caliber buck-and-ball load, it might have been already a little sore.
The muzzle-loading rifled muskets were cheaper to buy, cheaper to supply with ammunition and easier to service , but the ultimate economy was to raise the rate of fire per soldier. Even in 1859 the Secretary of War would note that a soldier with a good breech-loading gun would be the equal to two, possibly three soldiers armed with muzzle-loading muskets. If one breech-loader cost even twice as much as a muzzle-loader ( a Sharps rifle would be $36) that one soldier would consume much less materiel than two: need only half a tent, eat half the rations, wear out half the boots.
Fuller: The Breechloader in the Service
& #x200B;
& #x200B; | [
"In 1869, the War Department purchased far fewer weapons of all kinds than it had in the Civil War. Only three Frank Wesson carbines were purchased during the year, for $20 each. At the same time, it purchased, or had modified 13,098 Sharps carbines (listed as 'Sharps carbines, altered'), at approximately $4 each.\... |
Why can humans control an involuntary action (breathing) but not choose to control your heart rate? | To my understanding you have skeletal muscle that can control your breathing, but smooth and cardiac muscles (which control heart rate) are involuntary. Although, controlling your breathing can actually indirectly control heart rate as well.
If you’re asking why specifically smooth and cardiac muscle can’t be controlled, I’m not entirely sure there’s a 100% accurate answer for that question. | [
"It is impossible for someone to commit suicide by simply holding their breath, as the level of oxygen in the blood becomes too low, the brain sends an involuntary reflex, and the person breathes in as the respiratory muscles contract. Even if one is able to overcome this response to the point of becoming unconscio... |
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