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why are radio waves preferred for long distance communication? | Nice properties of radio waves:
1) The go through walls, unless they are made of metal.
2) They are bent by the upper layers of the atmosphere, so a radio message can go from the US to Europe.
3) Very sensitive receivers are mass produced at very low cost, so that only a very small part of the signal is needed to produce long distance communications. | [
"Amateur radio operators also discovered that long-distance communication was possible on shortwave bands. Early long-distance services used surface wave propagation at very low frequencies, which are attenuated along the path at wavelengths shorter than 1,000 meters. Longer distances and higher frequencies using t... |
Why will an outside observer never see someone cross the event horizon of a black hole? | Because you see things by receiving the light they emit that then travels from them to you. Any light emitted by the object inside the event horizon cannot reach you because it cannot get out. All light you'll ever receive will have been emitted by the body outise the horizon. | [
"Observers crossing a black hole event horizon can calculate the moment they have crossed it, but will not actually see or feel anything special happen at that moment. In terms of visual appearance, observers who fall into the hole perceive the black region constituting the horizon as lying at some apparent distanc... |
why do current comedy t.v shows, like 2-1/2 men, still use background audience laughter | Because audiences are used to it.
TV shows were largely adapted from stage performances, where the performers had to account for audience reaction. When those same viewers watched TV shows, they seemed *off* until someone got the idea of adding the laughter back in.
The practice has continued, and sit-coms seems weird without it. | [
"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... |
Are food related allergies amongst children rising, or are we just getting better at diagnosing now? | Increased hygiene and use of antibiotics reduce the diversity of the microorganisms living in and on us (human microbiome).
It is *very likely* that we develop more allergies because of this (at least compared to, say, 1850).
The lesson:
* Getting dirty might even benefit your kids
* Prescribing antibiotics unnecessarily is probably even more harmful than we thought... | [
"The most common food allergens account for about 90% of all allergic reactions; in adults they include shellfish, peanuts, tree nuts, fish, and egg. In children, they include milk, eggs, peanuts, and tree nuts. Six to 8% of children under the age of three have food allergies and nearly 4% of adults have food aller... |
what is the difference between a soft taco and a burrito? | it really depends on if you wrap it up entirely or not. if you leave it open, it's a soft taco. if it's wrapped up then it's a burrito. | [
"A burrito (, ) is a dish in Mexican and Tex-Mex cuisine that consists of a flour tortilla with various other ingredients. It is wrapped into a closed-ended cylinder that can be picked up, in contrast to a taco, where the tortilla is simply folded around the fillings. The tortilla is sometimes lightly grilled or st... |
How efficient are drinking fountains? | There is a balance between efficient and sanitary and ergonomic. A drinking fountain can be really efficient if you had to lock lips with it. But I wouldn't want to be the second person in line. Definitely not the 100th person.
A drinking fountain that shot short bursts, kind of like those sinks that only shoot about 3 seconds of water at a time (like an airplane toilet sink) thus giving you time to swallow and breathe would be more efficient, but would be messy and unsatisfying.
One that had a more narrow or low flow stream could be more efficient. It would take longer to get a mouthful, but less would be wasted while swallowing and breathing. But it would just take so long to drink.
I think a waterpik type thing, a flexible hose with a gun shape to squirt water in your mouth would be really efficient, like astronauts...except children, and people who act like children, would use and abuse them, all would be broken within a day anda lot of water wasted on shooting people.
A drinking fountain with cups would have little waste.
We'd also call it a sink. | [
"A drinking fountain, also called a water fountain, is a fountain designed to provide drinking water. It consists of a basin with either continuously running water or a tap. The drinker bends down to the stream of water and swallows water directly from the stream. Modern indoor drinking fountains may incorporate fi... |
How come only wet hair can stick to the shower wall? And when it dries up, it doesn't fall off? | I'll answer this question in two parts:
Firstly water has high surface tension, when something is forcing to it spread out (the hair in this case) it will want to bind to a surface, in this instance the wall.
To answer your second question; your hair has grease and dirt in it (no offence), this mixes in with the water. As the water evaporates the grease will be forced to move closer and closer together until the water dries up and the grease is acting like a glue holding the hair to the wall. | [
"Excessive or rough brushing can cause breakage. This results in frizz because the hair is stretched out of shape before it breaks, so that the shorter hair that remains tends to spring outward, away from the main body of hair. Backcombing can be damaging, as can combing curly hair when it is dry. Excessive use of ... |
what does "creative destruction" mean (economics)? | When Apple started selling the iPhone, everyone bought one and said: "Hey, this is awesome! It does so much more, and looks so much better, than my Blackberry." Everyone was happy... except RIM, who makes Blackberries.
That was an act of creative destruction on Apple's part. They created something better, and it destroyed a competitor's product. RIM might whine about how it isn't fair... and they might even be right. Never the less, they're screwed now. | [
"According to Schumpeter, the \"gale of creative destruction\" describes the \"process of industrial mutation that incessantly revolutionizes the economic structure from within, incessantly destroying the old one, incessantly creating a new one\". In Marxian economic theory the concept refers more broadly to the li... |
if the world trade centers were destroyed by the government what would be the benifit? | THEORETICALLY: It would cause a public uproar that would lead to a uniting of patriotism and a outcry for war. War means a lot of money for a lot of businesses, and up to a point, increases favor and confidence in the government who is responding. They said the same thing about FDR and Pearl Harbor. | [
"As owner of the World Trade Center site, the Port Authority has worked since 2001 on plans for reconstruction of the site, along with Silverstein Properties, and the Lower Manhattan Development Corporation. In 2006, the Port Authority reached a deal with Larry Silverstein, which ceded control of One World Trade Ce... |
how does chromatography work? | You pass a mixture through a column which is made of some sort of medium. The parts of the mixture which are attracted to the medium will go through at a slower rate. The parts that don't like the medium will speed through. When the mixture comes out of the column it will be separated. The faster-moving parts come out before the slower-moving parts.
It is a lot like telling people to walk down the aisle of store. If the aisle is filled with toys, then the children will stop every so often and look at the toys while others may walk straight through without stopping. Or it could be an aisle filled with books. The more literary types will stop and look at the books while other will walk straight through. Or it could be an aisle filled with shoes. You can analyze and separate people by making them walk though different aisles in a store. That's what is happening in chromatography at the molecular level. | [
"Chromatography can be described as a mass transfer process involving adsorption. HPLC relies on pumps to pass a pressurized liquid and a sample mixture through a column filled with adsorbent, leading to the separation of the sample components. The active component of the column, the adsorbent, is typically a granu... |
How much does the centrifugal force of the earth affect between the equator and the north/south pole when you jump. | At the equator the centrifugal acceleration term is 0.03392 m/s^2 . At either pole it's 0. On the other hand, the gravitational acceleration term varies by only 0.6% from the pole to the equator, so let's assume it's 9.81 m/s^2 and constant. So at a pole if you jump it's 9.81m/s^2, at the equator it's 9.77608 m/s^2. A difference of 0.3%.
edit - messed up my math | [
"At the poles, the gravitational acceleration is 9.8322 m/s. The difference of 0.0178 m/s between the gravitational acceleration at the poles and the true gravitational acceleration at the equator is because objects located on the equator are about 21 kilometers further away from the center of mass of the Earth tha... |
Why isn't the Oort Cloud belt-shaped? | The relationship to the other planets has catapulted them into a spherical orbit [_URL_2_](_URL_2_)
And the distances mean that it doesn't follow normal planar system dynamics.
[_URL_0_](_URL_0_)
This is unlike the [_URL_1_](_URL_1_)
| [
"In a satellite image, they look like distinct leaf-like or spokes-on-a-wheel patterns that stand out from the rest of the low-lying cloud field. However, why they have this shape or how they are formed is not known, but recent evidence suggests that the interaction of both radiation and precipitation may help to o... |
why can't you be paralyzed from only the waist up? | The nerves go down from your brain. Everything below the break in the nerve stops responding to input from the brain because it can't communicate with the brain anymore.
If things *above* the break have stopped working, that means your brain has stopped working, which means you're dead. This does happen sometimes, such as if the break is right below your brain (e.g. a properly performed hanging that snaps the neck). | [
"Paralysis is a loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage as well as motor. In the United States, roughly 1 in 50 people have been diagnosed with some form of permanent or transient paralysis. The... |
Is there any scientific basis in the adage "Opposites attract"? | There is evidence, but it's to the contrary. [Assortative mating](_URL_1_), where individuals mate more with those that share traits (geno- or phenotypic) than those who don't. See also, [homophily](_URL_0_).
The one big exception is sex/gender, where disassortative is more common: There are far more females with males. | [
"Attraction, which refers to interpersonal attraction, is a positive attitude that corresponds with a likelihood to respond to another in a positive manner. Carl Hovland argued that one of the three main classes of stimuli that determines the success of persuasive attempts is the observable characteristics of the s... |
X-ray Diffraction with Lasers | Yes coherent x-ray sources such as free electron lasers (like the LCLS at SLAC) are able to resolve much greater detail in the fine structure around Bragg peaks. The most useful way to consider the information content of this finely detailed low angle scattering is to consider its location in reciprocal space and how beam coherence contributes to this. Information about the shape of a protein or nanoparticle will be encoded in this region (not in the form of Bragg peaks themselves, just intensity around a given reflection, but it will be Friedel symmetric as well if there is no strain present) because the edges represent the largest spatial frequencies in the object. More importantly if the transverse coherence length of the beam is not sufficiently long (at least 2x greater than the width of the object for most coherent diffractive imaging algorithms) this information will be washed out by phase mismatch between x-rays scattered at different sides of the object. Basically high coherence is useful because in many instances we want to analyze the structure of non-crystalline or quasi-crystalline objects and with sufficiently great coherence length and sampling, a class of iterative phase retrieval algorithms can be applied that enable this.
Edit: Clarity | [
"The laser produces hard X-rays, 10 times the relative brightness of traditional synchrotron sources and is the most powerful x-ray source in the world. LCLS enables a variety of new experiments and provides enhancements for existing experimental methods. Often, x-rays are used to take \"snapshots\" of objects at t... |
why is organic food called 'organic'? | The word stems from a 1940 book suggesting that the whole farm is a living organism. [Details.](_URL_0_)
This is as opposed to an industrial and synthetic-chemical-based approach to farming, which treats the farm more like a factory or a machine. | [
"In the United States, “organic” is a labeling term for food or agricultural products (“food, feed or fiber”) that have been produced according to USDA organic regulations, which define standards that “integrate cultural, biological, and mechanical practices that foster cycling of resources, promote ecological bala... |
why do musicians and bodyguards use that hollow earpiece from the neck to ear instead of just regular earpiece? | Musicians often wear a custom molded ear piece that both offers hearing protection and plays music into their ear so they get feedback of the music or singing. A lot of old rockers have significant hearing loss because they didn't wear hearing protection on tour.
As for protective details like body guard or secret service, they wear small ear pieces so they can discreetly talk to each other while still be able to hear the crowd. For example if they had a cop style microphone/speaker clipped to their shoulders everyone would hear them call out..the guy with the blue sweater looks like he has something on his waistband.
_URL_0_
With an ear piece, only those on the team need to know.
| [
"The stapedius dampens the vibrations of the stapes by pulling on the neck of that bone. It prevents excess movement of the stapes, helping to control the amplitude of sound waves from the general external environment to the inner ear \n",
"The company's earpieces are used for hearing healthcare, recreation, indu... |
if oil is hydrophobic, then why are you supposed to apply body oil when your skin is damp? wouldn't absorption rates increase if your skin was dry? | It's more to prevent moisture from leaving your body while it is warm and your pores are open. You don't really absorb the body lotion, it sits on top of the skin and helps prevent dryness.
Also, they are formulated to help blend in with the skin (which is a bunch of cells surrounded by a hydrophobic layer..you know...to keep the moisture in), even if you aren't hot. | [
"One factor that determines whether skin is dry or oily is the amount of sebum produced by the skin. Sebum creates a fat-based film on the skin, which may also have an effect on skin hydration. The state of the skin’s stratum corneum plays a role in determining whether one is dry or oily as well, since this barrier... |
What is the status of Germany's WWII debt? | There is regular talk in Greece about Germany having to pay back what the Nazis effectively robbed from them by way of forced loans from their central bank while occupied.
[see here](_URL_0_):
> Upon their arrival, the Germans started to live off the country. They appropriated whatever they needed for their stay in Greece, and shipped back to Germany whatever they could lay their hands on: foodstuff, industrial products, industrial equipment and stocks, furniture, heirlooms from valuable collections, paintings, archaeological treasures, watches, jewelry, and from some houses even the metal knobs from the doors. The entire output of Greek mines of pyrites, iron ore, chrome, nickel, magnesite, manganese, bauxite, and gold was obtained for Germany. James Schafer, an American oil executive working in Greece, summed it up: “The Germans are looting for all they are worth, both openly and by forcing the Greeks to sell for worthless paper marks, issued locally” ( Mazower p.24). Mussolini complained to his Minister of Foreign Affairs Count Ciano: “The Germans have taken from the Greeks even their shoelaces”(Ciano p.387).
> The massive looting of the country, the hyperinflation generated by the uncontrolled printing of German Occupation Marks by German local commanders, and the consequent economic collapse of the country, precipitated a devastating famine. In addition to providing food for the 200,000 to 400,000 Axis occupation troops stationed in Greece, the country was forced to provide the Axis forces involved in military operations in North Africa. Greek fruits, vegetables, livestock, cigarettes, water, and even refrigerators were shipped from the Greek port of Piraeus to Libyan ports (Iliadakis p. 75). The International Red Cross and other sources have estimated that between 1941 and 1943 at least 300,000 Greeks died from starvation (Blytas p. 344, Doxiadis p.37, Mazower p.23).
> Nazi Germany and Italy imposed on Greece exorbitant sums as occupation expenses to cover not only their occupation costs but also to support the German war efforts in North Africa. As a percentage of GNP, these sums were multiples of the occupation costs borne by France (which were only one fifth of those extracted from Greece), Holland, Belgium, or Norway. Ghigi, the Italian plenipotentiary in Greece, said in 1942, “Greece is completely squeezed dry” (Mazower p. 67). In an act of utter audacity, the occupation authorities forced the Tsolakoglou government to pay indemnities to German, Italian and Albanian nationals residing in occupied Greece for damages, presumably suffered during military operations, which were never defined. The Italian and Albanian citizens alone received sums equivalent to 783,080 dollars and 64,626 dollars respectively! (Iliadakis p. 96). Greece, which was destroyed by the Axis, was forced to pay citizens of its enemies for presumed but unproven damages.
> **In addition to the occupation expenses, Nazi Germany obtained forcibly from Greece a loan (occupation loan) of $ 3.5 billion. [...] using as interest rate the average interest rate of U.S. Treasury Bonds since 1944, which is about 6%, it is estimated that the current value of the occupation loan is $163.8 billion and that of the war reparations is $332 billion.**
This, of course, was never paid back. | [
"Part of the agreement concerned debts to be paid after the reunification of Germany. For many decades this seemed unlikely to transpire, but in 1990 Deutsche Mark 239.4 million in deferred interest became due. These claims were repaid by means of \"Fundierungsschuldverschreibungen\" (Funding Debt Securities) with ... |
why is cosby's sentence 3-10 years? why isn't it a definitive number? | Because the law in PA stipulates that there must be a minimum and a maximum sentence, with the minimum being no more than half of the maximum.
This means that Cosby has to serve 3 years before being eligible for parole, and no more than 10 years if parole is denied. | [
"At the Old Bailey on 6 June 2016, Judge Peter Rook QC sentenced Huckle to life imprisonment on 22 counts with a minimum prison term of 25 years before being eligible to apply for parole. He will be first eligible for parole in 2041, assuming good behaviour and a belief by the Parole Board for England and Wales tha... |
How long did it take for messages to be delivered on the medieval age? | Please don't say primitive. That's derogatory. An essential part of life for the vast majority of people that have ever existed was the experience of only being able to communicate as fast as your legs, horse, or sails could carry you.
It could take 6-12 weeks for a ship to travel from Barcelona to Constantinople, depending on what kind of ship (sailing ship or oared galley), how many places you stopped, and how long you stayed at each stopping point. Weather, pirates, supplies, were a huge factor. A sailing ship could travel from Barcelona to Sardinia and back in something like two weeks; again, an oared galley would be faster. A message dispatched from the royal court in Paris could take anywhere from a 1-2 weeks to a month to get to the King of Aragon, in north eastern Iberia. I draw these numbers from my own research using medieval letters and commercial documents.
According to Goitein's *Mediterranean Society*, it could take a message 5 days to get from Alexandria to Fustat (Old Cairo); 12 days from Alexandria to Ashkelon (in modern Israel); and 10 weeks from Alexandria to Tunisia.
| [
"The story begins in the 12th century with Henry I, who appointed messengers to carry letters for the government. It is estimated that between 1100 and 1135, 4,500 letters were carried by these messengers. During this time, private individuals had to make their own arrangements. Henry III provided uniforms for the ... |
Why can some animals (like rats for example) be inbred with no problems but when humans do it we get all, sorts of problems? | While I dont know for sure but I believe even in humans, it takes a few generations before the chance of something happening is big enough for something to happen. At least in rats and humans their is a greater chance of them breeding with an outside gene line before defects happen. | [
"Two potential examples of primitively eusocial mammals are the naked mole-rat and the Damaraland mole-rat (\"Heterocephalus glaber\" & \"Fukomys damarensis\", respectively). Both species are diploid and highly inbred, and they aid in raising their siblings and relatives, all of whom are born from a single reproduc... |
Do we know what Georgy Zhukov's thought of the other best-remembered generals from WWII? | Hmmm... seems topical for me...
In my readings, I haven't come across too many direct statements from Georgy on his thoughts as to the military prowess of his Western counterparts. What little there is, he was mostly praising, but that is to be expected perhaps, seeing as they were obviously very carefully crafted to avoid offense in most cases. That isn't to say he was silent though! In regards to Montgomery, he called him *"Skillful, agile, and smart in a soldierly way"* although it should be noted Monty apparently annoyed Zhukov in their first meeting by trying to compare El Alamein favorably to Stalingrad, which Zhukov thought absurd.
The most interesting relationship though is between Zhukov and Ike, who had something of a genuine friendship by many accounts, and at the least a very deep mutual respect. They worked together for a time immediately after the post war - even visiting Moscow accompanied by Zhukov. Remarking on his impressions of Zhukov during that time, he wrote:
> there was no doubt in my mind that Marshal Zhukov was sincere.… His own adherence to the Communist doctrine seemed to come from inner conviction and not from any outward compulsion
> [...]"had longer experience as a responsible leader in great battles than any other man of our time it was clear that he was an accomplished soldier."
Zhukov, in his memoirs, returned the favor and described Ike in very complimentary terms:
> "I liked his simplicity, informality and sense of humour [...] It seemed to me that he understood the great sacrifices of the Soviet people.”
In later years, when he debuted as Defense Minister in 1955, Zhukov would complain about the deterioration of American-Soviet relations, and point to the good working relationship he and Ike had back in those months.
I know of at least one interaction they had in the '50s, while Ike was President and Zhukov Defense Minister, at a Summit later in 1955, where he was brought specifically because of their friendship. While that friendship wasn't able to bridge the gap, observers noted that both of them seemed very happy at the reunion, and got along very well in the two meetings they had at the summit. Ike wrote about it later and, referring to Zhukov as his "old friend", noted that he had lost some of the boastful but friendly confidence he once had, and now seemed weighed down and reluctantly repeating what he had been told to say. Funny enough, Zhukov's impression of the meeting was similar, and he noted to another of the Soviet delegates that Ike seemed withdrawn compared to how he was a decade prior.
Aside from that interaction, I know they maintained *some* level of correspondence, but I know that Ike was not totally aware of how Zhukov was being treated during his times of disfavor. I've read that during his second ouster (in the late '50s), under Khrushchev, which had been conveyed to the West as "retirement". Ike asked Kruschev about him, and was told "Don't worry about your old friend. Zhukov is enjoying fishing in his retirement and is no doubt writing his memoirs." In reality he was in political exile and while working on his memoirs, at that point, he had no expectation of ever seeing them allowed to be published. In response though, supposedly Ike sent Zhukov some fishing gear.
I think I might have veered a little off the original question there, but I hope this helps you get an impression of Zhukov's relations with the West! | [
"Georgy Zhukov was the most prominent Soviet military commander during World War II, winning several critical battles, such as the Siege of Leningrad, the Battle of Stalingrad, and Battle of Berlin. Stalin, Beria and Malenkov grew suspicious of Zhukov, worrying he possessed capitalistic tendencies, because Zhukov e... |
if bernie sanders' political positions reflect what americans think, why is he such an underdog for the presidency? | Many Americans share the same *ideals*, such as low-cost college, affordable healthcare, expanded social security. But Sanders position is extremely deficient in ways to *pay* for this that would be agreeable to all but a very slim minority on the political left. | [
"After the speech, the head of National Nurses United, the first national union to back Sanders, said, \"What we know about Bernie is that he will be there. He’s always been there as a fighter in the Senate, but that he will continue to be there for us. But most importantly, his message was, we have to be there, we... |
why do humans not sneeze in high pressure situations, such as sports? | I used to play on a sports team. I sneezed back then. Your premise is incorrect. Can you offer more information, such as where you got this idea?
Update: I just sneezed at work, despite being under a lot of pressure from my boss. | [
"There is much debate about the true cause and mechanism of the sneezing fits brought about by the photic sneeze reflex. Sneezing occurs in response to irritation in the nasal cavity, which results in an afferent nerve fiber signal propagating through the ophthalmic and maxillary branches of the trigeminal nerve to... |
18th-century battle formations | God I hate Reddit formatting. Sorry for the double post OP, RIP your inbox.
> In movies and reenactments of the American War of Independence, soldiers are seen standing shoulder-to-shoulder in long rows facing the enemy. If I were designing a battle formation that would make it as easy as possible for my troops to get shot, that is the one I would pick.
Please don't take offense to this, but this is coming off as unbelievably smug. I know it's likely not intentional but it plays off the trope that people in the past were somehow stupider than us today with our infinite knowledge and it does peeve me quite a bit. Please understand that Generals were not stupid and they were not keen on throwing men away mindlessly like comic book villains. This is more of a general historiographical statement, I'll narrow down to your question in a moment, but if you're looking back at a historical idea or concept or practice and are thinking, *"wow, that makes no sense at all -- why would they ever do that?"* understand that you likely are missing something or are given the luxury of hindsight. It's very easy to fall into the trap of criticizing those before us for things that are seemingly obvious today.
However, that doesn't really apply to the situation here. Line formations were by no means stupid and the most effective way of waging war well into the 19th century. Let's explore this.
> **Was it in use from the beginning of firearm warfare? If not when did it become common?**
Let me paint you a picture of the history of firearms up until the 18th century briefly. The very first muskets would be extremely heavy, lumbering, and not useless but not exactly amazing either. They would require a large stick with a "v" shape ([like so](_URL_0_)) These would be integrated into the formation of the time, that being pike formations. The firearms would be mixed in with the pikes, using their firepower to decimate enemy formations and the pikes protect them. As you might imagine, it was effective enough that basically everybody started doing this. Naturally, musket design would improve over the decades. They would become light, light enough for a man to carry and raise and aim it himself. Design changes to the loading process made it more reliable in poor weather and increased the rate of fire from 1 shot a minute to 3 and maybe even 4 if you were good. And finally one major improvement would be added, the bayonet. This would start to become popular in about the mid 17th century.
> **If so, why was it preferred over something more spread out?**
Let's cut to the core of the issue here, the fact of the matter is if you have 100 men spread out across 600 feet and 100 men packed into 150 or so feet, the tighter pack of men are going to overwhelm every single group of the other 100 they come across. They will overwhelm them with more concentrated and coordinated fire because everywhere they go it will be 100 men vs like 10 to 30. That's really, ultimately, the core of why line tactics exist -- concentrating your fire and your men allows you to control their movements, for them to motivate each other and reduce chance of running away when they do get shot at and charged at. Like was said above, skirmisher and light infantry are more difficult to organize to repel cavalry charges. They may be superior in the sense that they can more easily take cover and "pick off" enemy infantry but they are, essentially, useless in warding off enemy cavalry and are only useful in 'picking off' the enemy standing in a line if they have their own line protecting them from being smashed into.
Firing a single volley and then charging with bayonets locked was not uncommon and 100 men crashing into 20 men who occupy the same area will crush them every time. For the longest time skirmishers and light infantry were considered ancillary to line infantry and for good reason. They were just to vulnerable to the more concentrated firepower from line tactics, both in rifle and charge, and wouldn't have the weapons until about the late 18th and early 19th centuries to put them to use as a central component of an army. I really can not emphasize this enough. When we're talking about 18th century muskets, what is honestly more terrifying do you think? A couple of men being picked off in intermittent periods or 100 shots being shot at once in your direction. That's 100 bullets striking in your general region, the sound of 100 literal boomsticks going off, all that smoke, and then the roar of 100 men shoulder to shoulder charging in your direction with bayonets as you and your like 20 buddies in that small area look wide eyed at them coming right at you. You'd turn tail and run instantly.
With that said though, light infantry was a huge component of colonial armies. When you see things like Last of the Mohicans with the British only standing in lines taking their time firing while Mel Gibson and friends dance around and take cover, that's not how it worked. The British loved to use light infantry in their colonies and used them extensively in counter-guerrilla tactics. Line tactics were certainly used and a central component to Western warfare but they were not the only form and were not used idiotically in areas where they were not effective.
**The Napoleonic Wars (1792-1814, roughly) is when we begin to see the rise of light infantry taking a front stage role in continental warfare.** The Battle of Valmy was one of the first battles of the First Coalition War and was the really first battle showing the power of light infantry. The battle is noted mostly for its shocking show of professionalism from French artillerymen and was fought, primarily, as an artillery duel. Whenever the Prussians attempted to break the stalemate with their own infantry, French Tirailleurs would cause enough of a nuisance that the line infantry could not advance without unreasonable casualties -- holding them off. Although a technical draw (less than 500 people died out of a combined 66,000 men on each side) it began the period of the skirmisher. The French revolutionary armies would love skirmishers so much they would make pure skirmisher battalions -- to deadly effect. They would tend to operate in pairs and cover each other and never stray too far away from the line infantry. They also were capable of operating (relatively) independently and seize initiative, a pretty revolutionary freedom for infantry to be given in this period.
Every major nation would adopt or would professionalized light infantry brigades by the end of the Napoleonic Wars. The Prussians the Jäger, the French had Voltiguers and Chasseurs and Tirailleurs (all with slightly different designations and roles), the Austrians had Grenzers. Most of these, the Austrians in particular and the Portugese as well, were created originally from irregular groups of farmers (the Portugese word Caçadores literally translates to "Hunters") and would be gradually professionalized and organized into elite groups that men wanted to train into. They were, like I said before, relatively independent and that required a level of self discipline and mental strength and more importantly situational awareness that required a lot of training and rightfully was designated elite status. These men were, ultimately, not a bunch of untrained irregulars but a bunch of highly trained and highly intelligent professional soldiers who may not have been the bone or the muscle of the army -- that was the line infantry and the artillery respectively. They were the sinew that bound the two together and kept them strong and flexible.
> **When did it fall out of favor?**
1870 is about when. The Franco-Prussian War taught a story to Europe that many would not want to hear, but would harken in an age of new warfare. As opposed to the ACW just five years prior which used muzzle loaded muskets, the French and German forces would both be using breech loaded bolt action rifles using cartridges. The French had the Chassepot and the Germans had their infamous "Needle Gun" -- both with an effective range over a thousand meters. I'll quote from Michael Howard:^[1]
> *The German infantry did not, indeed, acquit themselves particularly well. The company columns in which they advanced into action disintegrated under fire into a ragged skirmishing line which quickly went to [the] ground, and which officers and N.C.O.s urged forward in vain. In the woods and close country which lay before the French positions the temptation to 'get lost' was sometimes overwhelming. Only close order could give the infantry confidence, and close order in the face of breech-loading rifles was suicidal. The answer to the problem, as the Germans discovered during hte course of the campaign, was for the infantry, so long as its armament was inferior to that of the enemy, to hold back and leave matters to the guns; and the German field artillery proved quite capable of settling matter sitself. Its range and rate of fire gave it, at the beginning of both battles, such an ascendancy that the French gunners -- including the dreaded mitrailleuses--were silenced in a matter of minutes.*
The Franco-Prussian War was a "half and half" war even more than the ACW. The Germans would have rapid mobilization -- over 250,000 men -- and would have staggering casualty rates. They would simply not be capable of assaulting positions without unacceptable casualties because of the deadliness of French riflemen and them not having the tactical flexibility to deal with it. The Generals had no idea what to do other than to just sit back and try and flatten the target area with their artillery and send in their infantry to mop up -- something we'll see tried again in a few years with much less success. However it worked now and, unfortunately, both sides didn't get a real picture of the futility of their tactics because of how much of a fluke the war was. You could argue it persisted into WWI briefly but that's a stretch. Ultimately the line tactics you know and love would die in 1871.
-----
**Notes:**
^[1] Howard, Michael *The Franco-Prussian War: The German Invasion of France 1870-1871*, pp. 118
Elting, John, *Swords Around a Throne: Napoleons Grand Armee* | [
"The Battle of Bazeilles was fought on 1 September 1870 during the Franco-Prussian War as a portion of the larger Battle of Sedan and was one of the first battles to feature modern urban warfare tactics. It took place in Bazeilles, France, a small village in the department of Ardennes near Sedan, and involved a for... |
Shisha vs. Cigarettes and the nicotine | No firm conclusions can be drawn from what you describe. There are far too many variables surrounding addiction; brain biochemistry, genetics, psychology (arguably = brain biochemistry), smoke constituents, the quality/purity of the tobacco burnt, the conditions of combustion, etc. etc.
The only thing that I know constitutes peer-reviewed evidence surrounding the negative health effects of shisha/sheesha smoking (rather than the addiction side), is with regards to the higher levels of CO (carbon monoxide) inhaled when smoking it (see [Baig *et al.*; (1982) *"A study of carboxyhaemoglobin levels of cigarette and sheesha smokers in Saudi Arabia"*](_URL_2_), [Al-Fayez *et al.*; (1985) *"Carboxyhemoglobin concentrations in smokers of sheesha and cigarettes in Saudi Arabia"*](_URL_0_), albeit quite dated papers, and just a [google search](_URL_3_)). Presumably the higher levels of CO produced are due to the tobacco being burnt in a relatively hypoxic (low oxygen) environment (under the foil, under the hot coal). CO isn't very pleasant and can cause brain damage and all sorts of other well-known impacts on health.
As regards to nicotine addiction, I'm not sure whether there is a linear relationship between nicotine concentration and addiction tendency/level/dependence/etc.. However, this appears to be a quite interesting read; [Jackson & Aveyard; (2008) *"Waterpipe smoking in students: Prevalence, risk factors, symptoms of addiction, and smoke intake. Evidence from one British university"*](_URL_1_).
| [
"A preliminary study found dokha has significantly more nicotine than other tobacco products such as shisha or cigarettes. Nicotine produces various pharmacologic and psycho-dynamic effects in the brain within seconds, which generally last for 30 seconds to several minutes, depending on the user's nicotine toleranc... |
How many times has Russia been invaded in winter? Why? | It's not that armies set off for Russia in the dead of winter, rather invasion plans that centered on quick defeat were never realized and armies became bogged down as winter set in. Napoleon and Hitler launched their campaigns in June, but of course their dreams of swift victory were never realized and winter took its toll on both invaders. At the turn of the 18th century Charles XII met a similar fate.
For a counter point, the Mongols had a few successful sieges during the winter months in Russia. But that comparison may be problematic because at the time of the Mongol invasions "Russia" was a loose assortment of kingdoms, not the nation/empire that would face the Swedes, French, and Germans centuries later. | [
"During the Great Northern War, the Swedish invasion of Russia led by Charles XII of Sweden against Russia's Peter the Great was notably weakened by the severe winter. Sudden winter storms and frosts killed thousands during the Swedish army's winter offensives, most noticeably during a single night away from camp t... |
Who was the first painter to manage a photorealistic style? | Buonarroti was probably the most consistent and most photo realistic. His sculptures were probably also the most realistic. But the Greeks were generally the first to accurately depict the human representation. Unfortunately the only mediums to survive since 500 A.D. were their statues.
However I think your trying to find the word Naturalism. In art, what you're speaking of is Naturalism. That dates back to 14th century. | [
"However, Hyperrealism is contrasted with the literal approach found in traditional photorealist paintings of the late 20th century. Hyperrealist painters and sculptors use photographic images as a reference source from which to create a more definitive and detailed rendering, one that often, unlike Photorealism, i... |
why a company like nestlè can take water out of a state/province for $2.25 per million litres, only to sell it back at a profit. who is letting this happen? | This is an explanation not just for this specific case but for large companies in general. These companies create jobs, and will also be paying taxes on a myriad of things. Sometimes the government will therefore sweeten the pot by reducing certain costs, knowing full well that overall they and the community will benefit from the implementation. This can end up being tax breaks, public utility rate break, favorable loans, etc.
**There are often a lot of benefits of having a large company implemented in the region, and as such local or state governments will often try to create incentives for that to happen.**
**Edit:** -Just thought I should add a couple of things based on some of the replies I've been getting. I replied to the OP in very general terms about why businesses might be given incentives because I assumed that was what was happening in this case, without looking up the specific example of Nestle in BC. I've now taken five minutes to look things up. This cost is associated with the Water Sustainabilty Act coming into effect in 2016. The 2.25$ is the current maximum cost in the province, so Nestle are not getting any special favors.
I also want to mention that a lot of people have been talking about corruption etc. Honestly that's completely off topic. Yes in general corruption in the world does exist, but assuming that everyone and everything is corrupt just makes you sound like a conspiracy theorist in an RV with a tin foil hat (that sounds like it's straight out of a game of clue). | [
"In December, 2017, the California Water Resources Control Board notified Nestlé that an investigation had concluded that the company does not have proper rights to about three-quarters of the water it withdraws for bottling, including water from the San Bernardino National Forest.\n",
"Currently, at the Sawmill ... |
why do songs sometimes sound at a different pitch when the volume is low? | Something harmonically important is not loud enough to establish the tonal center. Likely the bass. Without the bass notes (the chord roots), the tonal center can easily become ambiguous. Sometimes the remaining musical parts, such as guitar, piano, melody, etc., can still define the key and tonal center, but often in pop music, a lack of strong harmonic instruments isn't always present. | [
"Ranges are usually more narrow and often remain within an octave. Most songs tend to start on higher notes and descend down to lower registers as the song progresses. Tones may sound flat or sharp to some because natural modes are used rather than pursuing accuracy of pitch. The majority of these tones remain cons... |
the simulation theory. | Well, really simply explained The Simulation Theory states that we (as in the whole universe) is just a simulation in someone’s supercomputer, like the Sims or the Matrix. The idea is that somewhere outside this supercomputer there is a person/entity that perhaps wanted to know how the universe would have looked like if, for example, there were no water on earth or perhaps if the gravitational constant was different.
And because of the supercomputer a whole universe could be created as a simulation, in which we live, to test some sick idea that this person/entity came up with. Perhaps water is poisonous for them and they wanted to test what would happen if it actually were essential to life.
Then we are simply a process running in the computer to reach a final answer that would satisfy the person/entity and nothing else.
As far as I know there is no real evidence to prove that we are a simulation but the theory states three possible futures for us:
1. We go extinct within a near future before we manage to create enough computer power to run such a simulations ourselves.
2. We basically stop running simulations because we don’t need to make them more accurate
3. We manage to make a supercomputer that can simulate a whole universe in which we can make changes to the fundamental constants like gravity or such.
If we manage to reach alternative nr 3 there is no reason to expect that we are not a simulation from someone else.
| [
"A simulation is the implementation of a model. A steady state simulation provides information about the system at a specific instant in time (usually at equilibrium, if such a state exists). A dynamic simulation provides information over time. A simulation brings a model to life and shows how a particular object o... |
why can't some, but not all, people with spinal cord injuries walk? | The New Yorker did a pretty good article recently on spinal injuries [here.](_URL_0_)
TL;DR: It depends where the injury occurs, generally the higher the injury, the more severe. That's why if you "break your neck" it's usually going to paralyze you, if not kill you outright.
Additionally, we've yet to see anyone regain motor function after becoming a paraplegic because those nerves just won't regrow. This article explores a guy that just had a procedure that might change that. | [
"Spinal cord injuries have many causes, and result in a high comorbidity. In other words, victims of spinal cord injuries tend to develop many other health problems due to the importance of the spine in the central nervous system. SCI has a prevalence of up to 55 per million people in the United States alone while ... |
Is there any detailed map of Roman roads? I am interested in Roman roads in Croatia. | Please allow me to recommend this... _URL_0_
| [
"Today the Roman road is easily traceable on modern maps. Much of the route is followed by the A3, A24, A29 and A285, although most of the course through the modern county of Surrey has either been completely abandoned or is followed only by bridlepaths. Earthworks associated with the road are visible in many place... |
Is there a point at which eating will not stop you starving to death? | Yes, particularly if you are being intentional and specific about the word "eating" The result can be what's called refeeding syndrome
( [_URL_0_](_URL_0_) ) where your body is unable to process or absorb nutrients properly. Since the kidneys shut down first, your ability to balance electrolytes is severely impaired.
Typically small amounts of sugar water are given first, then later if the starving individual begins recovering, solid food can be reintroduced.
Other than that, as far as I know there's no strict amount of time that you can measure by for how long any given individual can starve before they are unable to recover. Their individual vitals and conditions need to be monitored.
[_URL_1_](_URL_1_) | [
"In those who are severely malnourished, feeding too much too quickly can result in refeeding syndrome. This can result regardless of route of feeding and can present itself a couple of days after eating with heart failure, dysrhythmias and confusion that can result in death.\n",
"Documented studies on the physio... |
Sources on how gunpowder/pike units functioned in 16th century and on, especially 30 Years' War, Tercios, Etc | I'd recommend two short but very dense and informative books on this by Osprey that also include lots of great illustrations: *The Spanish Tercios 1536-1704* and *Pike and Shot Tactics 1590-1660*. There are also quite a few other great books from Osprey dealing with 16th-17th century infantry tactics as well.
Basically, tactics changed somewhat from the early 16th century when pike and shot tactics gained prominence to the mid 17th century at end of the Thirty Years' War. The so-called tercio formation originated in Spain in the mid 1530s and quickly became the standard infantry formation, equivalent to later infantry regiments and battalions. On paper a Spanish tercio was supposed to contain 12 companies of 250 men (each further subdivided into ten squads of 25 men) equalling a total of 3,000 men, but in reality on campaign it would usually be nowhere near that and their average strength was about 1,500 men (Lopez, 12; Brnardic, p. 21). Other countries used tercios with a paper strength of around 2,000-3,000 men and the exact unit numbers varied. In the Habsburg Imperial armies during the Thirty Years' War the standard was anywhere from 60-100 files of 30-50 men each (Brnardic, p. 21). The name tercio means "third" because the original intention was for the tercio to be composed of 1/3 pikemen, 1/3 equipped with swords and bucklers, and 1/3 with firearms. However, this proportion quickly changed as the sword and buckler fell out of favor and was replaced with more pikemen who used the sword as a secondary weapon (Lopez, p. 34).
The standard tercio formation used during the Thirty Years' War was deployed in one dense block of pikemen directly flanked by small units of arquebus/calivermen (lighter versions of matchlock muskets which were usually quite large and cumbersome at this time) with larger blocks of musketeers at each of the four corners of the pike block (looking something like [this](_URL_0_)), but it could also be much more flexible and adjust itself to many situations and circumstances depending on terrain or whatever else (Brnardic, p. 21; Lopez, p. 37-39). During the period of the first half of the Thirty Years' War the tercios as a whole would often be arranged in a checkerboard or quincunx type formation with the large gaps between them being covered by the block behind (Brnardic, pp. 21-22). In the Spanish tercios each pikemen was meant to physically occupy one foot of space with one foot to each side and three feet to the front and rear. Musketeers were supposed to have twice that amount of space to load their guns (Lopez, p. 37). Because of this greater distance between ranks than files (files were lines of men standing abreast, ranks were those to the front and rear) and also the gap in the center of the formation for the rank of company standards, an equal number of ranks and files (e.g. 10 by 10) would produce a deep rectangle formation while a formation with twice as many files as ranks would produce a square. If a longer front was needed it could be extended the same way by increasing the ratio of files to ranks (Lopez, pp. 37-38).
The most experienced and best-equipped pikemen (called *coseletes* in Spanish) were placed in the front ranks and sides of the formation. About half of pikemen usually wore substantial armor. The small units of musketeers directly flanking the pike formation were called "garrisons" and usually consisted of 30-60 men armed with arquebuses or calivers while the larger musketeer blocks at the four corners of the formation were called "sleeves" and consisted of anywhere from 100-400 men, which were also sometimes accompanied by a detachment of halberdiers to fend off cavalry if they were surprised before they could retreat back to the pike block (Lopez, p. 38). Other times the musketeers were deployed as one group behind the pikes (Groot, p. 34). Often the "garrisons" on the flank armed with arquebuses and calivers would act as skirmishers to screen ahead of the main formation and soften up the enemy as well as take cover behind ditches and walls or inside buildings and then fall back to the pike formation if they came under serious attack (Brnardic, p. 22). Later as snaphance (early flintlock) and flintlock muskets started to become more common these were considered better, lighter, more reliable and favored for skirmishing as well (Groot, pp. 35-37). These light infantry tactics were the precursors of later light infantry units such as riflemen, jagers and chasseurs which would become very important in the 18th and 19th centuries (Groot, p. 35). Muskets in general were also lightened around the 1630s to make them less cumbersome and thus more effective for regular use as well as skirmishing (Brzezinski, p. 17).
How formations of musketeers fired volleys was done in different ways. Since loading matchlocks was time-consuming, in order to keep up a constant stream of fire musketeers would often fire in successive volleys, with the first rank passing through to the back of the line to reload after firing while the next rank advanced to take his place, but passing through the line could only be done well in relatively loose formations (Lopez, 38-39). Other times when the musketeers were in a denser block the first rank would fire at the same time and then peel off to either side of the line in order to regroup in the rear and reload. As the effectiveness of firearms increased in the 17th century, the ratio of muskets to pikes grew and by the 1630s in the middle of the Thirty Years' War the traditional tercio formation was being replaced by more extended linear formations with a higher proportion of muskets that could present a wider front to the enemy and thus take full advantage of firepower (Lopez, p. 38; Brnardic, p. 22). Maurice of Nassau (Dutch) and Gustavus Adolphus of Sweden were quick to devise and pick up on this new style of tactic while the Spanish continued to retain the tercio for longer, its one advantage being that it could easily box up and be defended from all sides (Brnardic, p. 22). As formations became more extended and placed more emphasis on muskets over pikes, musketeers started to fire massed volleys of three ranks at once with the first rank kneeling, the second crouching and the third standing upright -- the result of this could be devastating and further increased the musket's growing domination over the battlefield (Brnardic, p. 23). Another method was two rank firing where the musketeers would form two staggered ranks and advance to fire before falling back to reload while another line took their place (Groot, p. 35).
When the enemy approached, the musketeers would fall back behind the pikemen. If they were facing cavalry they would plant their pike in the ground at a 45 degree angle supported by their right foot while preparing to draw their sword with their right hand if they needed it. If they were facing infantry they would either hold their pike underhand at middle height which was easier or hold it overhanded which gave more leverage. Swords were used as a last resort and casualties were replaced by the men behind. When pike formations went toe-to-toe like this it was called the "push of pike" and it could be extremely bloody and terrifying. Meanwhile musketeers and arquebusiers would continue to fire from the flanks if possible (Lopez, p. 39).
There is more to say but that's a quick rundown on the organization of pike and shot formations and how they function, so to speak. Again I really recommend these books that I'll post as sources but if you have any other specific questions I can try to answer them.
**Sources:**
*The Spanish Tercios 1536-1704* by Ignacio and Ivan Notario Lopez
*Imperial Armies of the Thirty Years' War: Infantry and artillery* by Vladimir Brnardic
*Dutch Armies of the 80 Years' War 1568-1648: Infantry* by Bouko de Groot
*The Army of Gustavus Adolphus: Infantry* by Richard Brzezinski
*Pike and Shot Tactics 1590-1660* by Keith Roberts | [
"Pike and shot became a military standard in the 16th and 17th century. With the development of the bayonet the last major use of pike was the early 18th century with the weapon rapidly disappearing in Western European armies by the time of the Battle of Blenheim. A few pikes or half pikes and a few halberds were r... |
How much water does a body absorb when showering? | None. The epidermis is water proof. If it wasn't it'd allow ions to be leached from your body and bacteria in. | [
"A typical shower delivers 9.5 liters per minute (2.5 gallons per minute). Scientific studies that monitored hundreds of homes across the nation have shown that flow rates have little influence on the duration of the shower.\n",
"In addition to showering, baths were recorded in 47 percent of the sampled household... |
why do local commercials appear to always have something go wrong with them while big corporation commercials don't? | It takes money to make things look perfect. Most of the local businesses buy commercial air-time and the local broadcasting does the filming and editing.
Prime example, my boss (local business owner) was offered a 15 second spot during the superbowl for around $5000. It would only be aired locally and it would be the same commercial they had previously recorded and were already playing during regular programming (no fancy editing to make it look professional). Most of the major corporations can spend hundreds of thousands of dollars to make sure their commercials are perfect and aired in the perfect time slot. Most small businesses don't have that budget available. | [
"They exist to allow network television stations to send content to smaller local stations. The shows contain no commercials, just a small gap of blank video to allow the local station to insert their own. The exception for this is for \"barter\" syndicated programming, where only the commercials required to be sho... |
why do you insist on seeing people suffer? dares, pranks, jackass movies.. why do we love seeing people do difficult and painful tasks? | May not be the actual answer, just thought about it for a bit.
We don't like to see other people suffer. Would you go to a 3rd world country and laugh at every starving kid you see? Would you kick a physically-handicapped old man? Would you shoot someone and then laugh about it the next day?
I think we enjoy those dares, pranks, scenes in Jackass because it's dramatic irony. We know that they didn't mean it, but to the victim they know little else. So we laugh as a result, which is why dramatic irony is so powerful in stories and plays (etc.). We know that we meant little harm, but we got a big reaction of it and some find it funny. On the same token, I think this is also why some people find trolling pleasurable. | [
"People of all ages and cultures respond to humour. Most people are able to experience humour—be amused, smile or laugh at something funny—and thus are considered to have a \"sense of humour\". The hypothetical person lacking a sense of humour would likely find the behaviour inducing it to be inexplicable, strange,... |
why is it recommended that we wait a little bit after turning something off to turn it back on? | Most electronics contain capacitors. Capacitors act like little buffers to even out current in a system. A bit like having a header tank in a plumbing system. Think of them like tiny batteries that are constantly charging and discharging.
When you turn off an item, the charge in the capacitors doesn't go away straight away. You have to wait for a few seconds to allow it yo dissipate. The charge can be enough to mean that certain buffers or bits of memory aren't properly reset, so without waiting, the restart alone doesn't always fix it. | [
"BULLET::::- Because the device is never 'off' there is no \"turn on\" time, no problems with charge storage, and generally better high frequency performance and feedback loop stability (and usually fewer high-order harmonics).\n",
"\"Turn It On Again\" is a single by the English rock band Genesis, from their 198... |
how come people like bruce lee have such a small body, but are incredibly strong when athletes bigger than them are weaker even though they work out consistently? | Muscle size and muscle strength have a bit of an odd relationship. Bodybuilders, for example, aren't terribly strong despite being literally living displays of muscle tone. Strongmen, who participate in actual strength competitions, generally don't have so much muscle tone or agility and look more like big farmboys than bodybuilders.
Bruce Lee is a bit of an unfair comparison, because we're still not quite sure how he accomplished some of the crap he was capable of. For his size he probably was not actually tremendously strong, in the lifting/carrying sense, but he had a profound understanding of how to *apply* his strength, and his body was trained to an incredible level of *explosive* strength, giving him the ability to perform extreme feats of agility and dexterity and strike quickly and brutally. | [
"Mighty Man's main powers involve size manipulation. In the Protectors comic, he is able to grow greater than 20 ft and his strength increased exponentially with increased size. Mighty Man also has the ability to shrink at will, retaining his normal strength level while being the size of a doll.\n",
"An unusual p... |
what motivation to hackers/pirates have to share pirated media with the masses? | They are smart enough to realize that if everyone leeches but no one seeds, there won't be anything there.
Someone who has a history of providing content is more likely to get a good response if they request something they don't have.
Street cred.
Sticking it to the man. | [
"According to this philosophy, hackers, crackers, and phreakers are liberators of information which is being held hostage by agents demanding money for its release. Other participants in this network include cypherpunks who educate people to use public-key cryptography to protect the privacy of their messages from ... |
how do space shuttle engines work in space if there is no atmosphere to push against? | > III. For every action there is an equal and opposite reaction.
Newton really nailed this one. Grab a 10 pound bowling ball, a bag of flour, your child (no, I'm kidding), and hold it up against your chest. Now push it away from you as hard as you can. You should feel the ball moving away from you, but also, yourself moving away from the ball/bag/child. This is the "opposite reaction" he's talking about. The thing you're pushing is exerting force backwards into you, propelling you backwards. Same idea applies here. A force is applied (in space, often it's air jets for small motions), and the object reacts in the opposite direction. | [
"Intentional aerobraking is achieved by orienting the returning space craft so as to present the heat shields forward toward the atmosphere to protect against the high temperatures generated by atmospheric compression and friction caused by passing through the atmosphere at hypersonic speeds. The thermal energy is ... |
will cash ever become abolished in favor of debit/credit cards? | Countries will have hard cash for the forseeable future. The black market runs on cash. Cash also works when the power is out / when there's no internet signal. | [
"There has been a lack of cash due to the Venezuelan economical crisis and thus the demand and use of debit cards has increased greatly during the last years. One of the reasons why a noticeable percentage of businesses has been closed is due to a lack of payment terminals. The most used brands are Maestro and Visa... |
how do you best explain 4d to someone in a 3d world? | We are 3D creatures. Our shadows are 2D.
An n-dimension casts an n-1 dimension shadow.
Think about what could create a 3D shadow. | [
"2.5D (\"two-and-a-half-dimensional\"), 3/4 perspective and pseudo-3D are informal terms used to describe graphical projections and techniques that try to \"fake\" three-dimensionality, typically by using some form of parallel projection, wherein the point of view is from a fixed perspective, but also reveals multi... |
why dont speakers make the characteristic intereference sound anymore when there is an incoming call? | Ha yes, I remember that. You used to be able to hear that even before the phone rang.
The reason why it happened is a bit too complicated for me, but the reason why it doesn't happen anymore is that we don't (or barely) use 2G (GSM) networks anymore. These networks were on the 800-900 MHZ frequencies. | [
"Noise gates often implement hysteresis, that is, they have two thresholds: one to open the gate and another, set a few dB below, to close the gate. This means that once a signal has dropped below the close threshold, it has to rise to the open threshold for the gate to open, so that a signal that crosses over the ... |
What was the dating scene like for American women during WWII? | For a large proportion of women, dating simply ... stopped. Their boyfriends or fiancés were overseas - instead of being taken out to movies or dinner, they wrote letters and waited for possible furloughs. Single college students usually had to give it up as well, since their campuses had almost no men on them: most co-educational institutions were 75-90% women during the war.
Other women participated in dating much more freely than they would have been able to in the 1930s. (As I've discussed before in [this answer](_URL_0_), dating outside the home only became an ordinary courtship practice in the early twentieth century.) Between the general upheaval of wartime and the increased independence of many middle-class young women who were now working outside the home to earn a wage, social standards were becoming more permissive. The concept of "going steady" was strong in the 1930s, despite some adult warnings against selfishness and in favor of getting experience with a number of different girls/boys; for young women who were working in areas with an influx of unknown young men (soldiers on leave or at a local base, for instance, or workers who'd migrated), there was greater freedom to ignore the pressure from others to go steady. With the independence of a job, whether in an office or a munitions factory, they could also protest parental restrictions and feel allowed to make their own decisions about sex, or had more opportunities, if they were living on their own. It was this same class of independent working women who had driven the creation of the dating trend earlier in the century (see earlier answer again), so it's unsurprising that they would continue it in the 1940s.
However, don't think that it's a simple narrative of increasing "freedom" and laxity - one standard that shifted in what we could think of as the other way is how partnering in dances worked. In the 1930s, a young man and young woman were supposed to dance together until another man cut in; the only other way they could part is if she saw a group of her friends on the sidelines that she could join. In theory, this meant that part of the young man's responsibility at the dance was to get his friends to show the girl he was escorting a good time, which let her meet more people and feel more socially successful, and also let her escort feel more important due to the apparent competition; in practice, this meant that unpopular girls would be even more neglected as nobody wanted to "get stuck" on the dance floor. Over the course of World War II, due to the lack of American men in most towns, this did a complete 180. It became acceptable and then required for *women* to compete instead, holding onto the secure date she'd brought to the dance instead of allowing him the liberty of the floor. There simply weren't enough men to allow for the system. | [
"The First World War prevented many within a generation of women from experiencing romance and marriage, or having children. The image of the old spinster with a fading photo of her dead World War I soldier boyfriend on her fireplace mantel was common in films of the 1950s and 1960s. Likewise, in the American class... |
Where can I read more scholarly sources on Hawaiian "shark myths"? | Try [here.](_URL_1_) That's a link to the UH School of Hawaiian Knowledge's Knowledge Well database.
I haven't used this site before, but the University of Hawaii is really trying to cultivate their Hawaiian Studies programs, and that looks like it could potentially be a neat database. However, I'm at work so I can't really poke around it too much.
Here's the website for the [School of Hawaiian Knowledge.](_URL_0_) That might at least get you to the right person/department that could help you find the resources you're looking for if their database doesn't have what you're looking for. | [
"The Raw Shark Texts is the debut novel by author Steven Hall, released in 2007. The book was released by Canongate Books in the US and the UK and published by HarperCollins in Canada. The title is a play on \"Rorschach Tests\", which are inkblot tests. The novel is a work of Meta-fiction which uses Concrete poetry... |
We're constantly showered with radio waves. What prevents us from harnessing them and converting them into usable electrical energy? | Simply put: ambient radio waves have very little energy compared to ambient visible light. Per photon, visible light has thousands to millions times more energy than radio waves. Also, the sun produces a lot more visible light than radio waves. If you want to harness ambient electromagnetic radiation as a power source, visible light is the way to go (i.e. solar cells).
Note that you can definitely capture the energy in a radio wave and convert it to electrical energy - that is what radio antennas do. The amount of electrical energy is so small that it is usually not worth the effort. However, there are indeed some devices that are powered completely off of external radio waves, such as some [RFID tags](_URL_0_). | [
"Radio waves are \"nonionizing radiation\", which means they do not have enough energy to separate electrons from atoms or molecules, ionizing them, or break chemical bonds, causing chemical reactions or DNA damage. The main effect of absorption of radio waves by materials is to heat them, similarly to the infrared... |
Why do guns kill people so quickly (or are movies lying to me?) | Movies are lying to you. As you suspected, gunshot wounds are very rarely instantly fatal. A shot to the abdomen or chest is often not even incapacitating for some time.
Anecdotal, but relevant: my grandfather was shot through the throat by a high powered military rifle round, and wasn't at all sure what happened at first. Apparently it took him a good several minutes before he fell over and several more before he passed out, which gave him enough time to crawl back into cover. | [
"When people call a targeted killing an \"assassination,\" they are attempting to preclude debate on the merits of the action. Assassination is widely defined as murder, and is for that reason prohibited in the United States ... U.S. officials may not kill people merely because their policies are seen as detrimenta... |
why do most of the tv series that use apple (or something else) as their primary technology change the os or make it look fake? | It's similar to how they blur out logos on reality shows, they don't want to alienate potential advertisers. If they just show off an iPhone in their show, Samsung is not going to want to associate with them. Plus they're not being paid by Apple, so there's really no point to give someone free advertising. | [
"From the 1984 Super Bowl advertisement and \"Test Drive a Macintosh\" to the Apple Switch and Get a Mac advertising campaigns, Apple Computer has a long history of advocating its platform through traditional media. This also covers advocacy of the Macintosh hardware, peripherals and even lifestyle choices, with bo... |
Is the universe older in different places due to time dilation? | No, there's no time dilation between observers at a different place at the same cosmological time.
We do however observe time dilation with light from distant galaxies because the scale factor has changed in the time it took the light to travel to us. This time dilation manifests itself as a measurable change in the intensity. | [
"This is slightly different from the age of the universe which is approximately 13.8 billion years. The Hubble time is the age it would have had if the expansion had been linear, and it is different from the real age of the universe because the expansion is not linear; they are related by a dimensionless factor whi... |
How did Japan go about bringing electricity to its cities and towns? Did they hire westerners to teach them how to use it in order to make their own companies? | After the Bakumatsu and the end of the Tokugawa Shogunate in 1867, the Meiji government came into power. From 1868 to 1912, was the Meiji Restoration, where the old emperor was given back power and Japan became the first Asian power to adopt the European model of government and military. From this point, Japan took advantage of the Industrial Revolution and with the help of it's American and Western allies, it began to industrialize it's economy. In 1878, the first electrical grids were set up and used in limited applications with help from America. So yes, the Americans taught the Japanese how to use electricity. | [
"In 1871, a group of Japanese politicians known as the Iwakura Mission toured Europe and the United States to learn western ways. The result was a deliberate state-led industrialisation policy to enable Japan to quickly catch up. The Bank of Japan, founded in 1882, used taxes to fund model steel and textile factori... |
why do remote controls use infrared light instead of other wavelengths? | Very low wavelength bands are already occupied by radios and microwaves and have a lot of noise.
Visible light is visible of course.
Ultraviolet is too energy intensive to generate, and you definitely don't want to be shooting x-rays around the living room.
So the near-IR it is. | [
"The use of an infrared sensor to detect position can cause some detection problems in the presence of other infrared sources, such as incandescent light bulbs or candles. This can be alleviated by using fluorescent or LED lights, which emit little to no infrared light, around the Wii. Innovative users have used ot... |
why do some dead leaves tend to turn brown and others yellow/red/orange? what causes the difference in colours when they are dead if they were all green while on a tree? | Chlorophyll is the reason they are green. When fall hits, the change in temperatures and decline in sun exposure causes leaves to break down the chlorophyll. Depending on the type of tree and chemical reactions you get different colors.
This is what I've learned from Google basically.
"Chlorophyll? More like Borophyll" | [
"The leaves grow to be long and wide and have a deep glossy green upper surface. They usually turn red or brown in autumn, but depending on climate, site, and individual tree genetics, some trees are nearly always red, or even purple in autumn. Some brown, dead leaves may remain on the tree throughout winter until ... |
What was the role of slaves in early medieval Ireland? | Slaves would have performed the most menial agricultural labour depending on their gender - a male slave called a *mug* would have tended to livestock (in the case of Saint Patrick, for instance) and chopped wood while a female slave called a *cumal* would have ground oats in a quern and kneaded dough. Our knowledge of the sorts of labour performed by slaves in early medieval Ireland is mostly indirect, coming almost entirely from passages in legal texts. The bit about male slaves chopping wood, for instance, is cited in the *Corpus Iuris Hibernici* where it's mentioned that neither the slave or his master are at fault if he injures or kills somebody walking by while performing his labour.
Also, the text that you cited may not even be talking about actual slaves in every context. By the historical period a *cumal* had been reduced into an abstract value, usually payable in silver or gold rather than actual human chattel. Slavery was still widely practiced in Ireland but without a wider semantic context of where the term *cumal* appears, it's often safe to assume that a legal text is talking about an abstract value to be paid in precious metals or cattle than an actual female slave.
edit:
Actually, this separation between a *cumal* as an abstract unit of value and actual female slaves is reflected in the language of the Middle Irish original text: the *Lebor na gCert* does indeed stipulate the giving of slaves to various kings, but makes a distinction between a *cumal* (likely to be paid in gold or silver) and *mná* (lit. "women", the implication that they are slaves comes from their association with the other gendered term *mogaid* - the dative plural of a variant spelling for *mug*). | [
"Slavery became more widespread in Ireland throughout the 11th century, as Dublin became the biggest slave market in Western Europe. Its main sources of supply were the Irish hinterland, Wales and Scotland. The Irish slave trade began to decline after William the Conqueror consolidated control of the English and We... |
how do farmers milk almonds? | Almond milk is not actual milk. It is made by soaking almonds in water, then rinsing them and blending and grinding them well with water. Then the almond meal is filtered out and usually the remaining "milk" is sweetened slightly.
It is called milk because it is similar to dairy milk in appearance and texture. | [
"The basic method of modern domestic almond milk production is to grind almonds in a blender with water, then strain out the almond pulp (flesh) with a strainer or cheesecloth. Almond milk can also be made by adding water to almond butter.\n",
"Almond milk is a plant milk manufactured from almonds with a creamy t... |
How did the Byzantines/Eastern Roman Empire lose the Battle of Yarmouk? | An important thing to remember here is that these numbers are not accurate reflections of what actually happened. Modern historians of the Arab conquests are reluctant to believe the figures presented by the sources, the vast majority of which were written centuries later and were the results of a later political, cultural, and historiographical context. The earliest sources simply do not provide this information. From a sixth-century source we learn that Emperor Justinian's army, across his entire empire, consisted of 150,000 men - we should be cautious about this number, but that seems about right, as the largest armies recorded by contemporaries were in the tens of thousands. As a result, field armies larger than 20,000 are, I think, rather unrealistic for any point in the seventh century, particularly given the economic and political problems within the empire in the decades leading up to the 630s.
It is probable that there was a military engagement at or near Yarmuk, but the evidence we have is patchy. From c.660, the Armenian historian Pseudo-Sebeos recorded only an engagement of a 70,000-men strong army that was defeated by an Arab ambush, but the Romans only suffered 2,000 casualties. This may or may not be the genesis of later stories concerning the Battle of Yarmuk. At around the same time in distant Burgundy, the well-informed chronicler Pseudo-Fredegar noted that there were 150,000 Roman mercenaries against 200,000 Arab soldiers, both ludicrous figures. Yet the Burgundian historian also noted something rather interesting, that during the night before the battle 52,000 Romans died because they were smote by the Lord, which can be read as an indication that the plague struck the army and led to mass casualties - the plague was certainly active in the region and must have hindered operations even if there wasn't such an inconvenient mass outbreak. In the eighth century, the best source is perhaps Theophilus of Edessa, a court astronomer at the Abbasid court and whose now-lost history probably formed the core of a number of late chronicles in different languages, such as the work of Theophanes the Confessor (Greek), Michael the Syrian (Syriac), and Agapius (Arabic). In this telling, the Roman army consisted of 40,000 and they all died in the battle (which is of course highly unlikely). Another factor was raised however, as it appears that some Roman soldiers proclaimed one of their generals, Baanes/Vahan, as emperor, which could not have helped Roman morale or cohesion in the battle shortly afterwards.
I am less familiar with the Arabic sources, but I believe that similar differences can be detected in their accounts - a natural result of them being only written down in the late eighth century or even later. The sizes of the armies are not consistent, no more or less than the sources I've mentioned so far, so it is difficult to even establish the broad outline of what happened. These accounts are also affected by the addition of certain literary tropes, with the most extreme being the idea that the Roman soldiers were chained together to prevent them from fleeing; this is not attested in any Roman/non-Roman sources before this, but according to some Arab chroniclers this was the modus operandi of both the Romans and the Persians. This is surely an indication of their attitudes towards the two imperial powers, which they saw as decadent polities ripe for the conquest. It makes for a good story, but they cannot be taken as accurate depictions of what actually happened.
In reality, we simply don't know all that much about Yarmuk. I'm sure there was a major engagement, that the Romans (probably) outnumbered the Arabs, but beyond that we have to speculate. Perhaps the Roman forces were plagued by the.... plague and they may have faced internal unrest, yet for the actual battle itself we are completely blind. Pseudo-Sebeos' battle consisted of an Arab ambush, and according to the dependents of Theophilus, there was dust blowing into the eyes of the Romans. That's it, that's literally all the tactical information that we have from the earliest sources. I would not so easily dismiss the information preserved in Arab accounts, but there remains a big gap between historians working on different sources and I think that a better understanding will only emerge when we have a comprehensive overview of each source, their context, and their reliability. If we favour the early sources, how do we account for later Arab narratives? If we prefer Arab sources, how do we then explain the words of Pseudo-Sebeos, Pseudo-Fredegar, and Theophilus? In my view, to understand the Arab conquests, historians have to understand and study sources in Arabic, Syriac, and Greek together, but that is still pretty rare. Robert Hoyland, one of the few historians who follow this approach already, says only the following for the Battle of Yarmuk in his recent book on the conquests:
> Chroniclers now focus on an encounter that, in retrospect, was viewed as
> turning the tide against Byzantium and in favor of the Arabs: the Battle of
> Yarmuk. The name refers to the river that flows westward along the modern
> border between Jordan and Syria, and empties into the river Jordan, just south
> of the Sea of Galilee. The Arabs were led by two of their most famous generals:
> the aforementioned Khalid ibn al-Walid and Abu ‘Ubayda ibn al-Jarrah,
> who comes across as a tough but fair and pragmatic man. Both were from
> the prophet’s tribe of Quraysh, but whereas the former was from a clan that
> long opposed Muhammad, Abu ‘Ubayda had been a close companion of the
> prophet from the very start of his mission. The emperor Heraclius had traveled
> to northern Syria to obtain better intelligence about events and realized
> that matters were serious, and so he appointed his top general in the east, the
> Armenian Vahan, to take charge of the operation. Heraclius was particularly
> worried that the key city of Damascus was under threat, and so he dispatched
> messengers to instruct legions with spare capacity to release some troops for
> the defense of the Syrian capital. Vahan marched from Antioch with the main army, apparently routing a small Arab exploratory force on the way, in the
> vicinity of Homs. In the early summer of 636 “an enormous multitude of
> Saracens set out from Arabia and headed for the region of Damascus”; presumably
> the success of the initial Arab raids had encouraged many others to
> join the venture. Worried by this, Vahan wrote to Theodore, a patrician of
> Edessa and a senior financial administrator, to bring reinforcements, and he
> arrived with a further 10,000 men. Once all were assembled, they encamped
> together, right by the bank of the river Yarmuk.
>
> The Byzantine force looked very strong, but fortune was not on their
> side. An initial encounter in July 636 resulted in a defeat for the contingent of
> Theodore. This led to an argument between the latter and the Armenians, who
> subsequently proclaimed their own general emperor while abjuring Heraclius.
> Theodore’s men withdrew and the Arabs seized the moment to attack; some
> had been hidden in ambush around the Byzantine camp and they now jumped
> out and fell upon the enemy. The Byzantines attempted to flee, but the dense
> mud of the flood plain bogged them down and the heat of the sun overwhelmed
> them. Many thousands were either cut down by the sword or slipped down the
> steep sides of the river valley and were either crushed or drowned. The exact
> details of the battle are difficult to recover, but the loss of Byzantine life was
> evidently considerable, for it sent shock waves around the empire, even as far
> away as Gaul, where one Frankish chronicler spread news of the calamity. The
> latter and another Latin source blame at least some of the loss of Byzantine life
> on an outbreak of the plague, which was raging in Syria at that time.
As for why the Arabs won, I think it is important to remember that some Arabs were integrated part of the Roman world already and that Roman sources regularly report them as fighting on behalf of the Roman/Persian empires. We should not see them as unsophisticated, but instead as members of the world of late antiquity as well, most evident in the Ghassanid and Lakhmid confederations that thrived in the imperial borderland. Their power was broken by the end of the sixth century and we know little about the smaller Arab groups that took their place due to the paucity of sources, but I think that it is unlikely that we can dismiss the continuous participation of (some) Arabs in imperial politics. In my view, Arab 'raiders' were not nomads alien to the imperial powers, as the core of their forces must have been veterans well-versed in Roman/Persian strategies and the landscape they were battling in. Again from Hoyland:
> From this perspective the Arab conquests began as an Arab insurrection, that is, the early conquerors were not invaders coming from outside the empire but insiders trying to seize a share of the power and wealth of the Byzantine state. This helps explain why the Arab conquests were not particularly destructive: the leadership already had close acquaintance with the empires and they wanted to rule it themselves, not destroy it.
There were many, many other factors behind the successes of the Arab conquests and I attempted to summarise them [here](_URL_0_), but note that despite its length it is still not comprehensive. More research is being done all the time on this topic and I am confident in the near future we can further rewrite the conventional narrative of the Arab conquests, so watch this space! | [
"The Siege of Constantinople in 626 by the Sassanid Persians and Avars, aided by large numbers of allied Slavs, ended in a strategic victory for the Byzantines. The failure of the siege saved the Empire from collapse, and, combined with other victories achieved by Emperor Heraclius (r. 610–641) the previous year an... |
How were alloys such as bronze (which require extremely high temperatures) made by neolithic civilizations? | You're interested in the technological changes that marked the change from one culture to another? These kind of questions intrigue me too and also interested European archaeologists from the 19th C on.
The broad brush picture they paint is of successive waves of technological advances, spreading across the map like ripples on a pond. First the Neolithic Revolution, then Copper, Bronze and Iron Ages.
The Neolithic Revolution (c. 5000 BCE) is marked technologically by the use of ceramics and, with more impact, the adoption of agriculture. Farming led materially to settlement and increased populations, and these in turn to social stratification and institutions of leadership, ownership, and trading. These are some hallmarks of civilisation (an ill-defined term).
The first metal worked was copper, sometimes available as native metal which was soft enough to be cold-wrought with a stone hammer.
No special kiln or smelter is required to melt copper (melting point ~1000 C) - just an ordinary if hot fire. Fire would be known for its transformative actions (cooking, pottery), so it would not be a far step from hammering native copper to melting it in a ceramic crucible and then casting liquid metal into a desired shape, usually an axe.
Copper tools were used to craft the Pyramids, and a copper axe was amongst the possessions found with Otzi when he fell in the Italian Alps some 5,000 years ago.
Shortly thereafter, so the story goes, some bright early alchemist would've added the rarer, softer metal tin (melting point 232 C) to his crucible of molten copper, producing the paradoxically much harder alloy metal, bronze. Bronze as a material did not, in contrast to copper, occur naturally, and it's superior hardness and ability to keep an edge offered real practical advantages.
Now, if your talking extremely high temperatures, then we're into the smelting, casting and smithing of iron. Iron doesn't occur naturally and smelting it out of its ore requires yet more elaborate resources, such as charcoal fuel, bellows and smelter, and the specialist skills of a smith to work the metal.
References:
Gordon Childe. The Prehistory of European Society. 1958.
Colin Renfrew. Archaeology and Language: The Puzzle of Indo-European Origins. 1987 | [
"Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after \"natural bronze\" had come into general use. Bronze artifacts from Sumerian cities and Egyptian artifacts of copper and bronze alloys date to 3000 BC. The Bronze Age bega... |
When did the Continental/US navy start to build Man o' Wars and Ships of the Lines? | In 1776, when the Continental Congress authorized the construction of three ships of the line. However, only one ship was completed - the _America_ - and construction was delayed so much she was only in service by 1783, upon which she was transferred to the French Navy. She served only three years - and it seems she wasn't used much if at all - and was scrapped in 1786.
_URL_0_ | [
"After the Revolution, the United States Congress approved construction of six heavy frigates to form a nucleus of the United States Navy. One of the first three, the USS \"Constellation\", was constructed in Baltimore. \"Constellation\" became the first official U.S. Navy ship put to sea, deploying to the Caribbea... |
In ancient times, say for the Inca. What would happen if human sacrifice did not appease the Gods and relieve the drought? | **I. In which I question the underlying assumptions and chronology of your question**
First thing first, the Inca Empire had its heyday from the 15th to 16th Centuries CE, which is not "ancient." Second, the nature of Inca theology was not one that necessarily included a direct transactional relationship. Benson ([2001](_URL_2_)) notes -- while also making a connection between agriculture and the supernatural -- that the Inca pantheon was less a collection of individual personalities than it was forces of nature personified. Thus, periodic, seasonal sacrifices were a given, but these were less appeasement or payment than they were themselves simply part of the advancement of the calendar. One of our Andeans can expand on that, but I will note that a similarly non-personal relationship to deities existed a few thousand kilometers North, in Central Mexico. There, sacrifices were not so much direct payments to gods as they were assurances that the universe itself would continue; you honored the gods, you did not bargain with them.
**II. In which I redirect to something I know, also foreshadowing**
Speaking of Post-Classic Central Mexico (i.e. Ye Olde But Still Not "Ancient" Aztec Times), it provides an excellent test of what happens when a society that practices human sacrifice is confronted with a prolonged drought. As many people know ([and has been covered in this community before](_URL_5_)), human sacrifice was an integral part of Aztec culture, arguably surpassing every other human culture in its scale and overt intentionality. Certainly this would be a civilization that would quickly become uncivilized when a multi-year drought combined with early frosts left mid-15th Century Aztecs starving? Well, maybe not.
**III. In which we examine the overt response to the "Curse of Ce Tochtli," which means One-Rabbit, but don't read to much into that and the user name, we are not related, it's just a calender date**
In the year 1454 CE, or Ce Totchli in the Xiuhpohualli, the Aztec Empire was in a rough state. Duran (1994 Heyden trans.) notes that starting in that year "and for the next two years the drought was so intense in this land that the clouds remained closed as they did in the time of Elijah." If you are not as conversant with the Old Testament as a 16th Spanish Friar, however, he helpfully explains that this means that "it rained not at all" and notes that streams, rivers, and springs dried up, plants withered, and wildfires burned the land. Hassig ([1981](_URL_0_)) goes even further, delving into the calendrics to state that this was simply the culmination of a few bad years for crops and that the drought may have started back in 10-Rabbit (1450). He also notes that there was a plague of locusts in 6-Rabbit (1446) and a massive flood that submerged most of Tenochtitlan in 9-House (1449). Like I said, it was a rough time.
At the time, the Tlatoani (ruler) of Tenochtitlan -- the principle Aztec city alongside Texcoco -- was Motecuhzoma Ilhuicamina, more colloquially known as Montezuma I. He had been the chief general of the Aztec forces before becoming Tlatoani, was responsible for the first significant territorial gains outside the Valley of Mexico, had declared perpetual holy war on the Tlaxcallans, and authored the sumptuary laws that would later sharply divide the elites from the commoners in Aztec society. Naturally, his response to an on-going famine was to... open the granaries for a grain dole and impose export controls?
Well, yes, that's what he did. In 1454 Moctecuhzoma used the stores in the state granaries to supply maize and chia to the populace of the city, while also ordering that no maize was to leave the city, on pain of death. As Duran puts its, Motecuhzoma "put certain authorities in charge, to distribute the food. These men went to the different barrios and gathered the poor people, old and young, children and adults, and distributed the tamales according to the needs of each one. And a large bowl of gruel was given to each child."
As the drought continued though, the grain stores could not continue to support the city, so one last dole was given and a public announcement was given that there would be no more, and the poor of the city were released to leave the city in search of sustenance. Many of them ended up selling themselves, their children, or both as slaves to the Totonacs on the Gulf Coast, who had enjoyed abundant harvests.
**IV. In which we note what did, and did not, occur and ponder reasons why it did, or did not**
You'll note that nowhere in the above summary narrative was there an intensification of sacrifice. Instead, there was an organized state response to a public health concern. When that proved inadequate, practical -- if sad -- measures were taken by the citizens themselves. There are a few key reasons for this, the first of which comes directly from Duran ("quoting" the hugely influential politician-priest Tlacaelel):
> The nobility and merchants will not starve since they have their own granaries, foodstuffs, supplies. The people we pity, who need our assistance, are the old men, the old women, the little boys and girls who live in poverty and who have no place to go.
The famine, in other words, was not equally affecting all levels of society. Nor was it affecting all parts of the geographic region, as we can see from the Totonacs. Those who had the means to stockpile before, and trade throughout, the drought were insulated from its effects. Thus, there was no dire impetus from the upper classes to intensify religous sacrifice. In addition, there was the nature of Aztec sacrifice to consider.
As noted earlier, human sacrifices in Mesoamerica followed a calender cycle, so any intensification would have coincided with the cycle of the years, not necessarily the panic of the people. Furthermore, Aztec sacrifice was outwardly focused. While the Aztecs themselves partook in religious auto-sacrifice through cutting and piercing themselves, victims of mortal sacrifice were primarily outsiders. Thus, an intensification of human sacrifice during a famine would be undercut by the inability to wage war. At the same time, any ramp-up of internal sacrifices would be mediated by the fact that the most vulnerable persons (the very young and very old) to sacrifice were also mitigated by those groups being most vulnerable to the famine to begin with.
So what we see is a rational response by society to the long drought, followed by steps to prevent it in the future. Those steps included things such as intensifying agriculture in the Valley of Mexico itself, through terracing, irrigation, and dam building (see [Smith \(2003\)](_URL_1_)) as well as targeting the rich, wet lands of the coast for future conquests.
**V. OK, so maybe some extra people got sacrificed**
There are a few hints as to potential increases in human sacrifices during the 1454 famine. Townsend ([2009](_URL_3_)) points out additional emphasis on the rain god Tlaloc in a site right outside Texcoco. At the same time, De La Cruz et al. ([2008](_URL_4_)) have identified remains that suggest the child sacrifices to Tlaloc-Ehecatl-Quetzalcoatl may have intensified during this period. We still, however, do not see a massive breakdown of society or an apocalyptic scenario of slaughter and sacrifice though, simply hints of additional fervor to already long standing religous rituals happening against the backdrop of more practical responses.
**VI. A glib suggestion for further responses**
I'd love to have a medievalist tackle this question in the context of "Ancient" Europe, such as during the Black Death when the Flaggelants rose to prominence. That scenario has the advantage of a truly unprecedented event in the form of a pandemic, rather than something like drought, which was was an expected part of agricultural societies. | [
"Within Inca culture, it is reported that one element in the great Sun festival was the sacrifice of young maidens (between ten and twelve years old), who after their ceremonial duties done were lowered down in a waterless cistern and were immured alive.\n",
"The Inca took part in spiritual human sacrifices known... |
how does the "tuner" on a radio work? | There are two components in a radio that work kinda opposite of each other. They are the *inductor* and the *capacitor*.
An *inductor* is a coil of wire. When we pass electricity through a coil of wire, it stores some of that energy in a magnetic field. That's how electromagnets are made.
A *capacitor* is a "conductor sandwich." When electricity is applied to a capacitor, it stores some of that energy in an electric field.
They both store energy, but they do it in different ways. The higher the frequency of the electricity, the more power is allowed to pass through an inductor--but conversely, the higher the frequency, the less a capacitor allows through.
By matching a capacitor with an inductor in a circuit, we get a resonant frequency--a frequency where the capacitor and the inductor sort of reach a compromise. That frequency passes through the circuit, and any other frequency gets gobbled up by either the capacitor's electric field, or the inductor's magnetic field. In that way, we've selected a frequency on the radio dial.
The fun part: we know how to make variable capacitors and inductors; in other words, we can change the storage capacity of capacitors and inductors. In doing that, we can vary the resonant frequency of matched circuits; we change the frequency we allow through our circuit, allowing the radio to tune to different frequencies.
| [
"An electronic tuner is a device which tunes across a part of the radio frequency spectrum by the application of a voltage or appropriate digital code words. This type of tuner supersedes mechanical tuners, which were tuned by manual adjustment of capacitance or inductance in the tuned circuits. In a more practical... |
To what extent did Celtic peoples along Europe's Atlantic coast share culture and trade before Roman conquest? | Celtic language and culture came to Britain and Ireland a bit later than on the continent. In fact, it most likely spread through trade and political dominance, displacing languages that were probably related to Basque.
The Celts would have belonged to various smaller tribes, but all spoke a very similar language and worshipped the same gods. The Proto-Celtic language was actually very much like Latin. As they came into contact with Rome, the smaller tribes formed larger tribal confederations, often including Germanic peoples as well. In Gaul, they all united under Vercingetorix to defend themselves. They would have had a tribal affiliation, but they would have also been able to recognize that a neighbouring tribe spoke a language like theirs, while some Germanic or Basque tribe didn't. I'm sure this influenced how tribal alliances played out, but they still would have fought other Celtic tribes, allied with non-Celtic tribes, and shared a material culture with non-Celtic tribes that lived near them.
The Belgae were spread out between modern Belgium and Britain, and the British Belgae supported Vercingetorix, which is why Caesar launched a punitive expedition into Britain. From what I understand, they were newcomers into Britain, and if you read the Mabinogion, you'll find that there are two lines of mythical kings. One decends from Llyr, a British king, and the other from Beli Mawr, a Belgic king. The Belgic line is sometimes depicted as usurpers. There were already non-Belgic Celts there, but that particular tribe managed to spread itself between the continent and the island.
Many of the Roman roads throughout the empire were laid down over Celtic trade routes. That is to say, the Celts were really the ones to make the roads. The Romans just improved them. That should give you and idea of how well connected they were as far as trading.
The modern Celtic languages are very different from the Celtic languages that would have been spoken at the time. The continental Celtic languages (Noric, Lepontic, Celtiberian) are often all considered dialects of Gaulish. Gaulish was similar enough to Latin that Caesar supposed had letters written in Greek so that the Gauls wouldn't be able to read them if they were intecepted. It was heavily infected and didn't have most of the features that characterize modern Celtic languages.
Primitive Irish is the language of the Ogham inscriptions and it's still very much like Latin in that it relies on inflectional endings. Old Irish developed broad and slender consanants, retained the inflectional system while dropping many of the endings, and became a Verb-Subject Object language with verbal nouns instead of infinitives. Old Irish speakers brought the language to Mann and Scotland. Would Primitive Irish speakers have been able to understand Gaulish speakers? I really don't know, but the languages are at least very very similar in their features, while Old Irish is a vast departure from what Celts had been speaking on the continent.
Proto-Brythonic also lost the inflectional endings, but did away with the infectional system entirely. It became VSO with verbal nouns, and split into Old Welsh, Cornish, Breton, and Cumbric. Supposedly, it had been mutually intelligible with Gaulish at the time of Casear's conquest. I can't imagine that it would have been mutually intelligible with Primitive Irish.
| [
"Bob Quinn in his documentary series \"Atlantean\" speculates that western European Celtic culture is actually an earlier, pre-Celtic, Atlantic culture that included Atlantic Europe and people of the Maghreb such as Berbers and that it continues today.\n",
"Via the Bell Beaker culture, Atlantic and Central Europe... |
what's going on with the irs right now? | Some groups can apply for tax-exempt status if they are primarily involved in social welfare. Some political groups want to get in on this tax exemption, and not have to disclose donor names. It was found that when the words "tea party" or "patriot" were in the name of a group applying for tax exemption, their applications would be labeled for extra examination, so it appears that conservatives are being targeted by the IRS. This is understandably threatening not only to conservatives, but to anyone who expects the IRS to wield its power responsibly, so the gov't is trying to find who is responsible and stop this from happening again. | [
"The Internal Revenue Service (IRS) is the revenue service of the United States federal government. The government agency is a bureau of the Department of the Treasury, and is under the immediate direction of the Commissioner of Internal Revenue, who is appointed to a five-year term by the President of the United S... |
Why exactly did the Soviet Union go to war with Finland? Why were they so ill prepared? | Note, these posts are a copy of what I wrote on a similar question [here](_URL_0_).
There are several reasons for this, political and military ones, for both sides. I will start with the Finns.
**Finland**
*Military factors*
The Finnish army, while lacking in equipment, was by ww2 standards a very well-trained force. Finnish conscripts served 365 days of conscription with a for the time modern training regime. The Finnish tactics revolved around late ww1 German tactics as learned by the Finnish officers and soldiers in the German *Jäger* units. Defence in depth, flexible counter-attacks, foreposts at the front and most men kept safe further back during enemy barrages and tactical flexibility on the attack, with infiltration and tactical flanking were German tactics developed to deal with the ww1 battlefield. As it turned out, these were superb tactics for the close-range forest fighting and large stretches of woodlands lacking fronts completely.
The Finns realised the potential of the mortar, especially in rough terrain (as much of the fighting would be in) early, and while lack of funds prevented them from having as many as they would have wanted, they had attached them to the infantry battalions with their own forward observers (sometimes with radios, but most often telephone lines) which gave the Finnish infantry battalion some direct punch, even if the mortars did not fire within line of sight.
The Finns raised their infantry from counties and companies from muncipalities. This meant that most men knew each other from before the war, and kept unit cohesion high. There's a tendency in battle to forget politics and nationalism and fight only for your comrades. Having men you have known for a long time next to you in the trench helps immensly. High casualties could and did cause some villages to have their male population nearly wiped out by this though.
Inter-war Finnish training had, like in most Nordic countries, put some emphasis on rifle accuracy. What many contenintal nations considered "harrasing fire" with rifles, the Nordic nations trained to be sharpshooting. The Finns were especially good at this. Combined with a long and strong hunting tradition, this created a large pool of very good shots, culminating in Simo Häya who in 90 days had 542 confirmed kills.
The Finnish infantry battalion were one of the few to have integrated the SMG in the rifle squad. A Finnish platoon contained two SMG squads and two LMG squads.
Finnish infantry battalion 1939:
* 24xSMG
* 24xLMG
* 12xHMG
The Finnish air force lacked a lot of equipment, and had very few fighters. In one sense, this was a blessing in disguise as the air force, lacking in planes could be extremely selective in who it accepted into service. Only the very best of the very best among the conscripts were chosen to become fighter pilots and the training was extremely hard. Finnish pilots were required to pass extremely hard shooting tests. To add to this core of well-trained pilots, the Finnish air force was the very first adapter of the *rotten-schwarm/fighting pair-finger four* tactic - in 1932. The Germans developed the same tactics when fighting in Spain 1938, and the British switched after learning them the hard way over France 1940 and used them to good effect during the Battle of Britain.
Generally, Finland wasa decently egalitarian society. Many of the officers and NCOs were conscripts themselves and led by example and worked to earn the respect of the men rather than use strict discipline. Being used to long distances to central authority, these men were not beyond taking initiative without orders when the situation required it, which further increased the flexibility of the Finnish forces.
The Finnish troops were drawn from men used to long and hard winters and moving on skis during several months of the year. The Finnish army held regular winter exercises and skis were among the standard equipment of the army - in winter condition a unit on skis that have trained on how to move together can move very quickly in columns, where one man makes a track for the rest for a while, then stops, rests and lets the next man take over the hard task and then joins the last part of the column.
The Finnish army had inherited a lot of arms from the Imperial Russian army, as had the Red Army, and both sides used the same caliber on small arms, except for pistols, which meant that Finnish soldiers, always lacking ammunition, could loot the enemy dead an dload their rounds directly into their own weapons.
*Political factors*
While Finland has suffered a bloody civil war only 20 years earlier, the country had healed the most glaring wounds, and the threat of a foreign invasion did weld communists, socialists and whites together. Most Finnish communists who had fled to the Soviet Union had been killed in Stalin's purges, and one could not find that much support for Stalin even from the Finnish communists in Finland even before the war. During the inter-war years Finland had become a stable democracy - right wing movements such as the Lappo movement had disgraced themselves and lost all support and social reforms such as an 8 hour workday, vacation and social insurance had been enacted.
Generally, the Finnish people proved very willing to sacrifice for their nation and their democracy, and left and right united against the Soviets, something which the Soviets had not expected.
Stalin pulled out what few Finnish communists were left, several of them alcoholics, some of them from Gulag camps and created the Terijoki government (from the village where they were seated, one of the few slices of Finnish terrain the Soviets captured) under Otto Ville Kuusinen. This government proclaimed the "Democratic Republic of Finland" and signed to all Soviet demands. Leaflets were printed and distributed over Finland, often dropped by air. The promises were often completely out of touch with Finnish politics - one thing that was promised was an 8 hour workday! The Soviets expected a quick victory and to be welcomed by the Finnish communists. They were sorely dissapointed.
The first month or so of the war, the world cared little about Finland and its woes, but when it became clear that Finland was not only holding, but actually defeating Soviet invasion forces, a kind of mass hysteria of sympathy swept over the world to provide aid for Finland. While Germany, in order to keep relations with their non-aggression partner the Soviet Union, refused transit of arms and volunteers, there were still a lot of Hungarian and Italian arms that made their way to Finland. Britain and France, who both really needed to focus on re-arming themselves sent massive aid to Finland. The US sold or gave away much of its surplus arms, although most of the US weapons arrived after the war had ended.
However, nowhere did the mass hysteria reach the levels they did in Sweden. Sweden more or less depleted her stores of arms and ammunitions to send to the Finns. For example 147 000 mortar shells and 12,2 million rifle cartridges were sent to Finland. | [
"The consequences of the conflict were multiple: Although the Soviet Union gained new territories, the war pushed neutral Finland towards an accommodation with Nazi Germany. Furthermore, the invasion had revealed the striking military weaknesses of the Red Army. This prompted the Soviet Union to reorganize its mili... |
why do your emotions come in 'waves' after something very emotional occurs? | most emotions come from chemicals in the brain such as dopamine, oxytocin, adrenalin, serotonin, etc. When your brain starts to release these chemicals, it doesn't happen all at once. It begins to secrete them as if opening a valve. The flow starts slow until you get enough of the chemicals and your brain is filled with what it needs. So it feels like a wave because it starts slow and builds up until you're full. | [
"Though emotions are typically considered as having directedness and intentionality this idea has also been called into question. One might point to emotions a person all of a sudden experiences that do not appear to be directed at or about anything in particular. Emotions elicited by listening to music are another... |
[South America] How did Paraguay rebuild its population after the War of the Triple Alliance | On point 3 - In South America the landowning oligarchy was allied to foreign imperialism (specifically that of Britain). Their wealth hinged on exporting raw materials and importing manufactured goods from Britain. They did not see a need to industrialise (that wasn't their line of business), and Britain preferred things this way (as South American industrialisation meant competition).
Opposing this alliance were landless peasants and a string of nationalist movements aiming to break this neocolonial dependency.
Solano Lopez was one instance of a nationalist leader. Under him, Paraguay became a formidable industrial nation (the most industrialised in the region). It was the only country in South America with heavy industry - capable of building locomotives. Solano Lopez saw quite a bit of opposition from the landholding oligarchs in his country and elsewhere in the region, who all had an interest in seeing this economic model destroyed.
At the time, Argentina was ruled by former *Unitarios*, the party of the landholding oligarchs, who had fought a long civil war against nationalist *Federales*. Uruguay and Brazil were similarly ruled by landholding oligarchs. So Paraguay saw itself surrounded by enemies and no friends. Britain also made sure Paraguay's enemies were well armed and funded, protecting its business interests.
This is why the destruction of Paraguay was so thorough. It was done to destroy their embryonic industrial economic model, and as an example to other nationalist groups in the region not to break the dominant model based on agricultural exports.
edit: I'm Argentinian born, and I'll admit Argentina's role in this was shameful. Worse considering only 50 years earlier, Argentina, Paraguay and Uruguay were not separate entities. Leftist historians in Argentina today call it *The War of the Triple Infamy*, and liken it to a 19th C Vietnam. | [
"My analysis of comparative rates in nineteenth-century Latin America, together with a reevaluation of the Paraguayan censuses and household structure, indicates that the War of the Triple Alliance actually cost Paraguay between 7 and 18.5 percent of its prewar population… The evidence demonstrates that the Paragua... |
Does the influence of gravity from objects with mass ever reach 0? | It never reaches zero. The force of gravity is inversely proportional to the square of the distance, so it decays asymptotically to zero as you increase the distance (for example, if you double the distance, the force becomes 4 times smaller; if you increase it 100 times, the force becomes 10000 times smaller), but there is never a point where it reaches exactly zero. | [
"While not constant but varying depending on latitude and altitude, the numerical value of the acceleration caused by Earth's gravity on the surface lies between 9.74 and 9.87, which is quite close to 10. This means that as a result of Newton's second law, the weight of a kilogram of mass on Earth's surface corresp... |
why do some people look "good" fat, and others look "bad" fat? | Confidence goes a long way in this respect. If you feel less confident when you gain weight, you'll feel like you look less attractive. As for others, the ones that look good to you are likely not only confident but also dress for their body in a way that is flattering. Personal grooming goes a long way, too.
Different people have different body shapes, too, and society has deemed some more attractive than others. For example, there's the classic female hour glass that is largely considered the sexiest of female shapes because bigger hips are a sign of fertility. For men, even if they have a heavier midsection, having muscular arms and shoulders tend to make them more attractive because it is a sign of strength. That attraction is partly influenced human nature (the desire to survive and reproduce) and partly by traditional gender roles, but still very present today in determining what society deems attrative.
In the end, it's all about working with what you've got. | [
"Anti-fat bias leads people to associate individuals who are overweight or obese with negative personality traits such as \"lazy\", \"gluttonous\", \"stupid\", \"smelly\", \"slow\", or \"unmotivated\". This bias is not restricted to clinically obese individuals, but also encompasses those whose body shape is in som... |
we often hear about first world and third world countries/problems ect. but why do we never hear about second world? | Because the "Second" world doesn't really exist anymore.
Some definitions:
The "First" World - The United States and its Allies, Capitalists countries
The "Second" World - The USSR and its Allies, Communist countries
The "Third" World - Developing countries that the 1st and 2nd world fight over.
So the end of the Cold War essentially ended the "Second" world. The original definitions have nothing to do with economics (like they do today) but with where you were positioned in the Cold War. | [
"During the Cold War, the term Third World referred to the developing countries of Asia, Africa, and Latin America, the nations not aligned with either the First World or the Second World. This usage has become relatively rare due to the ending of the Cold War.\n",
"The only characteristic that Bauer found common... |
Why didn't warships of the 18th century use explosive shells against each other? | The overly glib answer to this is that they weren't invented yet, or at least not invented in a manner that would be useful. Although explosive shells date back to the 1300s, around the time of the invention of cannon, shells of the 18th c. were fused by an actual fuse (think of a cartoon bomb with a length of gunpowder) rather than a contact or some other type of automatic fuse. Although such a fuse could be ignited by the hot propellant gases when a shell was fired, it was more often cut to measure and ignited right before the shell was fired. The idea was that the shell would explode at the proper time, which was a tricky business to get just right.
Now there were ships of this period that did employ shells to, uh, shell enemy positions, mostly by firing the shell at a high trajectory with the idea of dropping it behind fortification walls or into entrenchments. [So-called "bomb ships"](_URL_0_) would have one or two howitzers fitted right forward, and would be fired by anchoring the ship at double anchor and aiming the gun or guns by means of a spring line ([this gets to the idea](_URL_1_)) attached to the anchor rope. Cutting the fuse just right so the bombs burst in the fortress, rather than bursting in air, was skilled business.
As far as firing shells horizontally, there were experiments on doing this from land-based howitzers starting around the time of the American Revolution, but they never took hold in the Navy. (The notable shell of the Napoleonic period was the shrapnel shell, adopted with great enthusiasm by the British army after 1803.)
It's hard to say exactly why something didn't happen, rather than did, but I would say that my opinion is that the fact that ships had a system of laying down gunfire that worked well and informed their doctrine; and that putting explosive shells on a wooden ship increased the number of things that could go badly wrong in battle; probably combined to delay their adoption until well after the Napoleonic period. | [
"Mortars were the only kind of naval armament to fire explosive shells rather than solid shot until the invention of the Paixhans gun. Since it was considered dangerous to have large stocks of shells on board the ships that were firing them, and because the reinforced mortar platforms occupied so much space below d... |
how do the companies behind linux distros such as ubuntu and opensuse make money if their os is free and open-source? | My boyfriend just told me that "they give you the car because they're the best know mechanics in town". | [
"Despite being freely available, companies profit from Linux. These companies, many of which are also members of the Linux Foundation, invest substantial resources into the advancement and development of Linux, in order to make it suited for various application areas. This includes hardware donations for driver dev... |
why when someone records the cinema screen using a camera, the video becomes ugly and not the same as the screen? | A few things.
1) Most cameras record at 30fps, where as most films are 24fps. This leads to weird things happening due to the timing of the frames such as flashing and flickering.
2) Cameras, especially cheap ones, struggle in low light. Also, movies are constantly changing between bright and dark meaning that cameras have to adjust often and they struggle at this.
There are more reasons, but that's the basics. | [
"Cinemagraphs are still photographs in which a minor and repeated movement occurs, forming a video clip. They are published as an animated GIF or in other video formats, and can give the illusion that the viewer is watching an animation. A variation is a \"video snapshot\" (clip composed like a still photo, but ins... |
why do people open their own mouth when spoon-feeding a baby? | Because babies imitate what they see. So when you open your mouth at them, they copy you and open theirs. It helps them understand that it’s time to feed. | [
"Mouthbrooding, also known as oral incubation, refers to the care given by some groups of animals to fertilized eggs or their offspring by holding them in the mouth of the parent for extended periods of time. Although it has been observed in a variety of animals, most mouthbrooders are fish. The parent performing t... |
why can adults get diseases only by touching grabpoles on public transport while children's immune system profit from eating dirt/playing in dirt? | Children do not benefit from eating dirt. Children are more exposed to germs and therefore slowly build up immunities to common viruses. Not diseases, by the way.
Adults do not get diseases only by touching public transport poles. Adults are more segregated than children, who are in schools all day with hundreds of other kids. Therefore, it is more likely that they would contract a virus when squashed into a small area with lots of people. | [
"Young children are at the greatest risk of infection because they play outside and tend to place contaminated objects and dirt in their mouths. Dog ownership is another known risk factor for transmission. There is also a significant correlation between high \"Toxocara\" antibody titers and epilepsy in children.\n"... |
how do you calculate the 20th percentile of a cumulative frequency? | ELI5 isn't for walkthroughs. Try /r/learnmath or /r/cheatatmathhomework.
Thanks. removing. | [
"Cumulative frequency analysis is the analysis of the frequency of occurrence of values of a phenomenon less than a reference value. The phenomenon may be time- or space-dependent. Cumulative frequency is also called \"frequency of non-exceedance\".\n",
"Frequency values are calculated first and without reference... |
what's the deal with movie theater shootings? | Like any mass shooting, they get tons of Media attention, inspiring the next round of mentally unwell individuals to become copycats. Combine that with virtually non existent security in movie theaters, and you've got an easy target full of people. | [
"The shooting prompted an increase in security at movie theaters across the U.S. that were screening the same film, in fear of copycat crimes. It led to a spike in gun sales in Colorado and political debates about gun control in the United States.\n",
"In February 2016, Under the Gun Theater was named one of the ... |
why is there so much abuse in the foster system? shouldn't there be more extensive background checks? | Contrary to popular belief, the government does not know everything about everyone.
Background checks are an inherently flawed system. If someone is abusive as hell but has never been arrested and convicted, for one reason or another, their legal background will be clear. Just like how the various murderers at recent, high profile mass killings were able to legally purchase firearms and pass a NICS check. They simply never entered into the system, and never in any way serious enough so as to appear on a permanent record. [[note: this is not about gun control, I'm just using that as an example for background checks being incomplete and little more than security theater ]]
There's not enough, time, manpower, or funding to enforce the laws we already have, much less build up a truly comprehensive background database on the entirety of any one country's population. Not to mention the loss in personal privacy and freedom that such a thing would require, or the disgusting amount of government abuse that could arise from such a database.
Freedom has a huge price and sometimes it's not pretty.
On another note, I'm sure individual case workers care about the foster kids they oversee but the system as a whole doesn't. It's a revolving door and they just want the door to spin as quickly as possible so as to maintain the funding, with little regard for what comes in or out. | [
"Studies in the U.S. have suggested that some foster care placements may be more detrimental to children than remaining in a troubled home, but a more recent study suggested that these findings may have been affected by selection bias, and that foster care has little effect on behavioral problems.\n",
"A further ... |
why is it that i’m some cases of people being stabbed/impaled, the removal of the item that did the stabbing/impaling (not the initial puncture itself) causes them to bleed out and die? | If the object has punctured an artery (a blood vessel that carries pressurized blood pumped from the heart), the object may be filling in its own puncture-wound in the artery wall while it is in place, thereby preventing the blood from spilling out.
But as soon as the object is removed, the puncture-wound is opened, the blood gushes out, and the person dies very quickly. | [
"Many of the victims were burned with a car cigarette lighter, usually around the genitals, chest, and face, and several were found with extensive blunt force trauma to the face and head. In several instances, foreign objects were found inserted into the victims' rectums while other victims had suffered emasculatio... |
how can a single cpu core run multiple threads and how is that beneficial? | The problem is that when people talk about this subject, they cut out so many technicalities that they miss the entire point (like other threads about the same subject in this sub). I'll try to cut as much of the technical stuff that I can.
So think of it this way: a core has 2 parts. One deals with integer operations and one deals with floating point operations (decimal numbers).
& nbsp;
The first situation where 2 threads per core can help:
**The integer part of the core is used, but not the floating point part.** That means that if conditions are right, the second thread is ready to be executed in the floating point part.
However this _rarely_ happens, because data from a thread has to be executed serially, instruction by instruction. You cannot cherry pick floating point operations to perform, you will have to perform whatever comes next from the thread. This makes the likelihood of a floating point operation coming from one thread while an integer operation is coming from the other thread quite unlikely. Especially because these threads have differing priorities. As a result, this does not give a very good performance increase.
The second situation:
**The CPU core is stalled, doing nothing because of other bottlenecks.** One good example is when the CPU is waiting for the RAM to give it data.
The CPU has a very fast memory, called cache memory. When an instruction comes the core searches for the necessary data in cache. If it doesn't find the data, it asks the RAM for the data. RAM is very slow compared to cache, so the core is just waiting for the RAM to return with the data it needs. During this waiting period the core can execute the second thread, thus negating the performance penalty.
& nbsp;
So practically simultaneous multithreading makes the processor work closer to 100% over a given period of time. Without a second thread the processor has more 'breaks' between its operations.
Do note that these breaks happen extremely fast and you can't see them in task manager's CPU usage for example.
It's a very complicated piece of tech and I've only scratched the general idea. There's _a lot_ more to explain, like other types of core stalls, but I think that's more than just the general idea.
I hope my answer was clear enough. If you have any questions ask. | [
"For each processor core that is physically present, the operating system addresses two virtual (logical) cores and shares the workload between them when possible. The main function of hyper-threading is to increase the number of independent instructions in the pipeline; it takes advantage of superscalar architectu... |
why does the doubling your money strategy not work in gambling? | In theory it works, but in practice eventually you'll lose enough bets in a row that you either run out of money or the casino won't take your bet. Your 20th bet in a losing streak would be over $1m. | [
"The strategy can pay dividends when gamblers successfully reduce the potential winners of an event to a select few from the field or when information about runners not expected to perform well does not reach the market (so as to affect the odds), making it profitable to back the rest of the field.\n",
"The secon... |
How did the cicada's mating cycle come to be 17 years long? Wouldn't a cycle of only a few years be necessary to avoid lining up with predatory mating cycles? | It's very beneficial to take a prime number as the length of your mating cycle. If you'd take 4 years for example, any predator that has a cycle of 1, 2 or 4 would eat a large part of the population. If you take a prime number like 7, then predators with a cycle of 2, 3, 4, 5, 6 will all miss you.
The bigger the prime number the less you will be eaten. 19 would probably be an even better cycle, and 23 even better.
If a predator's cycle happens to synchronize with that of the cicada, they will probably evolve to have a different cycle again (or they will shift their cycle by one year.) 18 years won't make it better though, so they will probably choose 19 years. | [
"Like other species included in \"Magicicada\", decim periodical cicadas have synchronized development with a long larval period underground (13 or 17 years, depending on species), followed by mass emergence, quick development to adult flying forms, and massed singing choruses of males that attract many females. Ma... |
how the us lost the ability/technology to land on the moon, after 50 years of industry advancement | We haven't. In fact Nasa plans on putting a man on the moon in 2024. Planning missions like these takes a long time in advaced, because literally every contingency needs to be planned for. Not to mention we plan to use it as a test for a new rocket design. These things have to be built, people need to be trained to fly them, Experiments need to be decided for the launch, etc. These things take time. | [
"As the 1960s ended, the United States had made two successful manned lunar landings. Many Americans lost interest afterward, feeling that since the country had accomplished President John F. Kennedy's goal of landing on the Moon by the end of the 1960s, there was no need for further missions. There was also a grow... |
Why didnt Soviets force Finland to adopt a socialist government after WW2? And why did Finland never join the Warsaw Pact? | Finland was never occupied by Soviet troops. They never got past a certain point. At that point in time in 1944, the Soviets were more interested in moving as fast as possible into Germany rather than trying to move deeper into Finland and possibly occupying it. When Finland sued for peace, both sides agreed to terms that were similar to what was agreed back in 1940 - there were territorial changes but Finland remained a sovereign and independent nation. It would not be occupied by Soviet troops, and any German troops still on Finnish soil would be the responsibility of the Fins themselves.
To force Finland to adopt socialism, the Soviet Union would need some sort of a way to install a socialist government through a coup or a rigged elections or something similar. Without having troops on the ground, they lacked the means to do that. | [
"Finland was left to the Soviet sphere of interest in [[Molotov–Ribbentrop Pact]], and when it refused to allow the Soviet Union to build bases on its territory, it was attacked by Soviet forces in the [[Winter War]] (30 November 1939 – 13 March 1940). After the war, Finland unsuccessfully sought protection from th... |
if most youtube ads can be skipped after 5 seconds, why don't advertisers start making 5 second ads? | Sometimes I watch the rest of the ad because the first five seconds caught my attention.
So I don't know, but if you utilize your 5 seconds wisely you can drag people into your 30-second spot. Also, I've seen 4-minute ads. That's really… | [
"Debuted in 2016, these ads show the beginning portion of a 45–90-second ad before a blue screen disclaimer appears telling the viewers that the ad is being fast forward to the end portion so that they can get to their video faster. If an extended version of the ad or just the regular 15-second ad is shown on sites... |
why websites using cookies to better target your ads is considered such a bad thing. | Because I don't want family visiting sites on my laptop and seeing penis pump ads on sites just because I clicked on an ad last night.
Edit: er umm... not that I need one :( | [
"Targeting, viewability, brand safety and invalid traffic all are aspects used by marketers to help advocate digital advertising. Cookies are a form of digital advertising, which are tracking tools within desktop devices; causing difficulty, with shortcomings including deletion by web browsers, the inability to sor... |
in computer architecture, what is the difference between core and a microarchitecture? | A multi-core processor is a way to say that you have multiple independent processing unit on the same physical chip. Each is called a core and they will be identical in the chip for computers but in a cellphones the might have 4 energy efficient but slower cores and 4 faster that use more energy to give you both long battery life and high performance when it is needed. Even if they are independent that can share some stuff lime memory controllers.
& #x200B;
The architecture the design of that processing unit. All PC processors can execute the same code wit the same result but how it it done will change and the manufacturer come upp with new way to do it faster. So the architecture is just a name for that design.
It is a bit like year models for cars where they make improvement and changes and designate. But a bit difference since you can have a cheap processors with 2 core and a more expensive with 16 but the core are and only the number is different. | [
"The term \"core\" comes from conventional transformers whose windings surround a magnetic core. In core memory, the wires pass once through any given core—they are single-turn devices. The properties of materials used for memory cores are dramatically different from those used in power transformers. The magnetic m... |
how do astronomers know a black hole has the mass of 20 billion suns? | A black hole is basically just a star that's collapsed in on itself, becoming very, very dense. Our Sun has a lot of gravity because it's so massive, but the only stars that can become black holes are hundreds of times bigger than our sun. So every black hole that's born has a similar mass to the star that it was "born" from.
I haven't seen the video you're talking about, but a black hole with a mass equal to 20 billion suns would be a supermassive black hole, thousands of times stronger than the one at the center of our Milky Way galaxy. We can pretty easily tell its mass by studying the things that orbit it. The speeds and distances at which objects orbit a body tell us how much of a gravitational force it's putting out; the more gravity, the more mass. | [
"As reported in \"Nature\" of 28 November 2012, astronomers have used the Hobby–Eberly Telescope to measure the mass of an extraordinarily large black hole (with mass approximates 17 billion Suns), possibly the largest black hole found so far. It has been found in the compact, lenticular galaxy NGC 1277, which lies... |
gas stations often have signs on the pump to turn off your phone and pager while using the pump. i doubt that anyone does this. what's the concern and is it a valid one? | The concern is about the possibility of an electrical spark igniting the fumes of fuel. The source comes from an investigation of a fire at a gas station where they could not determine a cause many years ago. One difference was the car owner had a cell phone, (relatively new at the time. Hardly anyone had a cell phone) There was a theory that the phone was the source of the spark and caused the fire. Highly unlikely but potentially possible for the technology of the time. It was never proven and never has been shown a normally operating phone can start a fire but it kinda stuck as a precautionary measure.
Mythbusters did cover this but could not ignite gas under any normal circumstances. Only with modifying the phone to create a spark could they ignite the gas. I think they called it plausible as a damaged phone may cause a spark but odds are so slim of all the conditions to be right for a fire to occur it would be near impossible to happen. If it was true, gas stations would be burning down left and right with all the phones people have now a days. | [
"Gasoline theft (sometimes known colloquially as fill and fly, gas and dash, and drive-off) is the removal of gasoline from a station without payment. The thief will usually use some form of decoy to prevent nearby witnesses from noticing the lack of payment until they have left the station. Common decoys include p... |
what do all the parts of a url mean? | The first bit before the colon (http, https etc) refers to the protocol in use. Http is the only common one but you can use others like ftp:// - which will use file transfer protocol. The next bit after the // is the address of the website - _URL_0_. After than, comes the file/script you are loading. Eg fubar.html is an html page. It might be in a directory, like tarfu/fubar.html. If there's a ? And some characters after the page, they are parameters and options being passed in. So you might see the total look something like:-
Http://www._URL_0_/tarfu/fubar.htm?some & options & here. | [
"Some characters cannot be part of a URL (for example, the space) and some other characters have a special meaning in a URL: for example, the character codice_17 can be used to further specify a subsection (or fragment) of a document. In HTML forms, the character codice_8 is used to separate a name from a value. Th... |
how do some vehicles drive nearly submerged without stalling or breaking down? | This is much easier with a diesel engine, particularly older ones which don't have masses of electronics. They're nearly all mechanical and don't much care if they're under water.
More modern diesels have to have more attention paid to waterproofing connectors and sensors and things, but provided you can keep the water out there's not much problem. Just make sure the air intake isn't awash. The exhaust, provided you're not too deep, can just take care of itself.
Petrol engines are harder because the high voltage ignition system is harder to waterproof, but in principle it's the same - keep the water out of the electrics and air intake and it'll do fine. | [
"An operational vehicle can be driven on-board under its own power. This is a delicate operation, particularly with tracks, as their precise steering is limited. In particular neutral steering, where one track goes forward and one backward causing the tank to turn on the spot, is likely to either damage the loadbed... |
how do wills get invalidated by a court? | > How can a court decide whether to honor or invalidate a will?
One way that a will can be invalidated is if it's deemed to be incomplete. For instance, a will that was first drafted 30 years ago, and doesn't mention children who are 25 years old, would be invalidated, because it's assumed that the children were *supposed* to have inherited something, and only didn't because the will was out of date.
This can also happen when the will is current, but doesn't mention a close relative (like a child or sibling), because it's argued that the deceased simply neglected to mention them, and they're actually supposed to be included.
This is why, if you don't want to leave anything to a close family member, the will typically states *explicitly* that they get nothing, so they can't argue that they were simply overlooked.
Another way that a will can be invalidated is if it specifies that the estate be used to do something illegal. For instance, if a will said, "I leave nothing to my children. Instead, all of my money shall be used to hire a hitman to kill my ex wife", the will would be invalidated, and the money would instead be distributed to the person's children. | [
"The effect of the ruling is that if a court declares the last in a series of wills to be invalid \"ab initio\", the deceased is deemed to have died intestate. The court will not give effect to an earlier will, as it had already been revoked.\n",
"A will may also be revoked by the execution of a new will. However... |
what is it about riding in a car that makes babies fall asleep? | Vibration, warmth, hum of the engine all come into play. I wish I could find a link to a study, but if the cars are moving at a relatively good speed, children can't focus on objects outside of the vehicle. Without anything to pay attention to they lose interest and their bodies choose rest instead. | [
"Sleep-deprived driving (commonly known as tired driving, drowsy driving, or fatigued driving) is the operation of a motor vehicle while being cognitively impaired by a lack of sleep. Sleep deprivation is a major cause of motor vehicle accidents, and it can impair the human brain as much as alcohol can. According t... |
Do black holes have an escape velocity? | > Or is this a nonsensical question?
Bingo. I know you mentioned "what if + time travel," but entertaining these miss the point of physics because they disregard physics entirely.
In any case, as long as you kept outside the horizon you would have an escape velocity. Once inside, well shucks. | [
"The cluster's velocity is thought to originate by being ejected by the supermassive black hole at the center of M87, when the black hole stripped the outer layers of HVGC-1 off, it also ejected the remaining core with greater than escape velocity.\n",
"Defined a little more formally, \"escape velocity\" is the i... |
Health differences between animal protein and plant protein? | Animal protein is a complete protein. It contains all nine essential amino acids that our bodies need. Vegetable proteins do not generally contain all nine amino acids. However, by combining foods you can make a complete protein. Rice and beans are an example.
| [
"Contrary to certain rumors that animal-based protein is more suitable to trigger muscle growth than plant-based protein, a study by Mangano et al. (2017) could not provide any evidence for this. In contrast, if combined properly, plant-based protein can even have a higher biological quality. A combination of one p... |
why are different parts of the world more prone to extreme weather? | There's a few factors that are happening. The big ones are:
* the middle of the planet is warm
* the poles of the planet are cold
* warm air expands (pushing other air) and rises
* warm water evaporates
* cold water condenses and falls
* the rotation of the planet produces some pretty predictable ocean currents and winds, too
Add all those consistent factors up, and it means there's major patterns to how weather works.
So what ends up happening is, warm tropical oceans develop storm systems pretty often. Then, winds tend to push them in the same general directions. We see this with the Atlantic ocean and the eastern side of the USA, hurricanes form in the tropics and are drawn north. Over in the Pacific? Similar land & sea setup, similar formations: Pacific typhoons get pushed to China, Korea and Japan. | [
"The effects of weather on sport are varied, with some events unable to take place while others are changed considerably. The performance of participants can be reduced or improved, and some sporting world records are invalid if set under certain weather conditions. While outdoor sports are most affected, those pla... |
if colds are caused by viruses and bacteria, why do i often feel like i get a cold from just staying at low temperatures without proper clothing? | When the weather is cold, people spend more time inside. The close proximity of people and lack of air circulation (Due to lack of open windows or doors) causes any contagious illness - Like a cough or a cold - to be spread much easier. | [
"Well over 200 virus strains are implicated in causing the common cold, with rhinoviruses being the most common. They spread through the air during close contact with infected people or indirectly through contact with objects in the environment, followed by transfer to the mouth or nose. Risk factors include going ... |
how do services such as 'bongo' in the uk know any details about a person, and are they even real? | From their FAQ:
> HOW DOES BONGO WORK?
> BONGO works thanks to a number of intelligent human researchers and a very sophisticated software application with a huge database.
So officially, they say it's a mixture of human researchers and a software application. Presumably they are collecting info from social media, publications, etc
You'd be shocked how much info the average person puts out there. I'm sure they're looking at who you have Liked on facebook and then tracking if that person has Liked your photos and that kind of stuff. | [
"Mr. Big (sometimes known as the \"Canadian technique\") is a covert investigation procedure used by undercover police to elicit confessions from suspects in cold cases (usually murder). Police officers create a fictitious grey area and/or criminal organization and then seduce the suspect into joining it. They buil... |
why do all legitimate streams run almost half a minute behind their television counterparts? | i'll give you a placeholder answer that you can hold onto until someone who's worked with this technology at a lower level can speak on it.
There is a lot of preprocessing that goes on with video, sending it too. You don't get sent raw video data of every pixel at every frame - which is why you can select the quality at any one point. This preprocessing didn't really exist for TV since the bandwidth is always there to send pretty much whatever the camera and microphone read from the world as-is into the air for your TV to pick up.
This preprocessing can be put into analogy if you've ever worked on project based office jobs. You tell your manager what you think you can do according to a relatively conservative estimate, and in that you factor in many things which might not be related to you (in this case, it would be latency or server load from twitch or anything else that would consistently slow down packets from being sent, read, processed and spat out to consumers).
We can deduce from this that the shortest common stream delay is probably that conservative estimate that most streaming services recommend (or sometimes, enforce). | [
"Notable applications to publish and record live streams at the same time include MotionCaster, Open Broadcaster Software, Wirecast, and XSplit Broadcaster. They are used to publish streams to Youtube, Facebook, Periscope and Twitch.tv, among others.\n",
"While streamers as we know today didn't come about until t... |
why you’re told to wait 30 seconds when unplugging a modem or dvr. | Electric circuits have parts called capacitors which can hold on to electric charge for a bit.
In order for the modem to get a fresh start, you are told to wait a “longer than necessary just to be safe” amount of time, so all the capacitors will discharge. | [
"The DTR signal is an important call control signal for a data modem. According to the RS232 standard, dropping DTR from active to inactive for at least two seconds tells the modem to disconnect (end) a call or data connection. \n",
"BULLET::::- The modem interprets the Data Terminal Ready (DTR) pin as a signal f... |
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