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How has Hitler's "Mein Kampf" been used by historians? How has it been misused by others? | I'm going to give one, fairly well known to historians, example. A.J.P. Taylor famously did not read Mein Kampf, and discounted both its importance for understanding Hitler and any correlation between what Hitler wrote and his later actions.
I should note that this is an example of misuse by non-use. Taylor, to make a very hefty book short, argued that Hitler was not really the central cause of the Second World War, and moreover, that his ideology was not "that" important. If I'm remembering correctly, he used an analogy about a car accident to describe the outbreak of war.
Taylor not using Mein Kampf was such a big deal that Burk went out of his way to show conclusively that Taylor had not even read it. The book was and is indeed a gold mine of sorts, but only insofar as one is intent upon examining Hitler. This is why Taylor was pilloried to the extent he was: he essentially devoted a book to Hitler's innocence (in starting the war, Taylor in no way denies or diminishes the Holocaust or Hitler's role in it) but could only do so by ignoring key evidence (Mein Kampf) or alternating between claiming Hitler was lying, and not really serious at various points. If you ignore Mein Kampf, such an approach is indeed feasible, if still incredibly flawed. However, if you include Mein Kampf, the approach just sort of implodes immediately. Hitler was quite proud of being a warmonger...it was one of the only consistent and non-contradictory things in Mein Kampf. So for Taylor to argue that a warmonger who was actively seeking a war in order to overturn the established order and build a race based empire, was actually not really that keen on war, caused no small amount of scoffing in the halls of history faculties.
As for how it will be different. I don't really see a "My Struggle, and Zombies" or any other light hearted stuff as being viable. A big part of that is of course, the book is awful. I don't just mean that in the message, plenty of books have hateful messages. Hitler was a good performer, and maybe a great deal is lost in translation, but that book reads like a rambling cavalcade of idiocies.
The first time I read it, I was so disappointed. I had steeled myself, reminding over and over that no matter how convincing or brilliantly the argument might be made, racism, anti-Semitism etc. are simply too easy and weakminded approaches to have in life. When I'd finished I was utterly confused. How could this book convince any even semi-educated person that Hitler was the star to hitch a wagon upon? I very suddenly understood how initially, educated Germans, much of the Jewish population, and those outside Germany honestly thought Hitler was some kind of comedian. Read seriously, the book is childish, riddled with contradictions and inconsistencies, and simply bad. Read as an intentionally paranoid cry for justice, blaming any party but oneself, the book is actually quite funny.
One use I could see for the book, which I'm claiming right now and will demand royalties for if it should happen to appear on the market, is toilet paper. Nothing could be more suiting or proper than to read a bit of Mein Kampf, and then do with it exactly what ought to be done. | [
"In \"Mein Kampf\" (1924-25), which was written while he was in prison after his failed 1923 putsch, Hitler combined elements of autobiography with an exposition of his racist political ideology . The personal reflections contained within \"Mein Kampf\" are nevertheless inaccurate and unreliable. In the work, Hitle... |
Does conservation of momentum violate the conservation of energy? | No. Energy and momentum are always conserved, but remember that momentum is a vector quantity with a direction, thus in your example the total momentum of both objects must remain zero (10-10=0) but that the individual momenta of each object need not be zero.
It is then important to determine whether your collision occurs *elastically* or *inelastically*. Elastic collisions preserve kinetic energy and momentum (thus the objects perfectly scatter). Inelastic collisions preserve momentum, but kinetic energy may be lost to heat, light, sound or deformation. The total energy is still conserved, but it is no longer all kinetic.
* _URL_0_ | [
"Conservation of momentum is a mathematical consequence of the homogeneity (shift symmetry) of space (position in space is the canonical conjugate quantity to momentum). That is, conservation of momentum is a consequence of the fact that the laws of physics do not depend on position; this is a special case of Noeth... |
Astrobiologists of Reddit, What would life in a gas giant probably look like? |
> Could life evolve in a gas giant and would it have to live on the core or could it live in the clouds?
Could life evolve? This is an unknown. We only have one instance of life to compare it to. There is speculation that it could.
> What kind of chemistry would it have to have and what kind of adaptations would we expect to see?
The chemistry would be dependent upon, first and foremost, whether life was possible. Then it would be dependent on what chemicals were available. The only chemicals we're familiar with as the basis of life are the ones we use - mostly carbon.
The adaptations would depend on the environment. Not all gas giants, like not all terrestrial planets, are alike.
[This](_URL_0_) is from Stephen Hawking's Universe, and may be relevant to your interest.
David Brinn, the SciFi author, postulated that the life forms in gas giants would grow very large to prevent being swept up or down in the storms of a gas giant, though I don't believe that's particularly scientific as his other ideas (in the uplift novels) pertaining to gas giant life forms seemed more a matter of convenience to the story.
There's also Ian Douglas's take on it in the Star Carrier series, where very (very) large buoyant life forms acted as hosts/platforms for tinier (roughly human sized) life forms. But again, purely speculation even if it is within the realm of possibility.
I only bring those two up because their knack for writing well and, at least in William Keith/Ian Douglas's case, propensity toward "hard" SciFi. | [
"The planet is a gas giant that is about in diameter. Like most gas giants, it has a solid core that consists of metal followed by layers of metallic gases. Many of the layers of gas are poisonous, and the pressure and temperature are far above what a human could tolerate. But from approximately down from outer spa... |
how does the alpha magnetic spectrometer detect dark matter? | This is probably not going to be put in terms simple enough for strictly adhering to this sub-reddit's mantra (explained as if you were five years old). Oh well, I tried. :|
Dark matter backstory, short version: By watching the motion of the cosmos, specifically, other galaxies, and even clusters of other galaxies, we have noticed that there are similarities in the movements of these galaxies, and even the stars within those galaxies. These movements are best explained by what we're calling "dark matter".
Dark matter backstory, long version: We see a lot of stars in each galaxy... billions and billions. These stars all kind of "glue" each other towards one another, and battle in a cosmic, billion player tug-of-war game. BUT, we notice that there seems to be a bunch of invisible stars also pulling in all these, adding more "glue" in to the galaxy, and more players into the tug-of-war game. This "glue", and the "ropes" of the tug-of-war game obviously symbolize "gravity". The extra gravity coming from invisible sources has so far best been explained by the term "dark matter". We still don't know if it forms in clumps, like "regular" matter does with stars and solar systems, but we know that a huge halo-shaped band of dark matter seems to surround each galaxy. Also, the way that galaxies collide and merge suggests that there's lots of invisible tugging going on, from stuff we can't see: "dark matter".
More background: In theory, there are little pieces of this invisible stuff, "dark matter", everywhere around (and possibly even inside) Earth, pieces about the size of atoms (SMALL). These dark matter pieces should be banging into each other, like really fast bumper cars... even atoms, which are regular matter, do this quite often. Some of the dark matter pieces should be going quite fast, and when they hit, something magic happens (the complexity of scientifically explaining this next sentence is too much, but it does have to do with E=mc^2). An electron (regular matter) and a positron ("anti-matter"... different than dark matter, mind you!) appear out of thin air!!
To answer the question: So there we are... up there on the International Space Station... with our super cool Alpha Magnetic Spectrometer (we'll call it AMS) instrument. AMS allows us to "see" electrons and positrons, and we point it straight out into space, away from earth, into the depths of the universe. Well, as it's turned out, we actually DO see some positrons. As of right now, the most likely explanation as to why these positrons are out there is because the little pieces of dark matter ARE actually colliding, like bumpercars, making positrons (and electrons too, of course) appear like magic.
We can't see these positrons on the surface of the earth, because they get obliterated by our atmosphere... if they touch our air, *BINK!*. A tiny explosion occurs. So, the best place to look for them is in space, and (for now) the best way to look for them is with AMS.
In the next few months, we'll gather more data which will allow us to say with greater certainty whether or not we really see the "fingerprints" of dark matter. | [
"The Alpha Magnetic Spectrometer, also designated AMS-02, is a particle physics experiment module that is mounted on the International Space Station (ISS). The module is a detector that measures antimatter in cosmic rays, this information is needed to understand the formation of the Universe and search for evidence... |
Is carbonated water still acidic after it has gone flat? | 'Flat' carbonated water is just water that is no longer supersaturated with carbon dioxide. It would still contain some residual CO2, depending on temperature, and would therefore still be very slightly acidic (ph 6 or so).
I'm not sure what you mean by still water. If you are talking about distilled water, it would probably have less CO2 than flat carbonated water. This is because the CO2 is driven off when the water is heated to boiling, and it is likely that the water would then have been condensed and bottled without having time to reabsorb much CO2 from the atmosphere. Nonetheless conventional distilled water still has some dissolved gases and for lab work that requires water with *no* dissolved gases, further degassing is typically needed. | [
"The acid gives carbonated water a slightly tart flavor. The pH level between 3 and 4 is approximately in between apple juice and orange juice in acidity, but much less acidic than the acid in the stomach. A normal, healthy human body maintains pH equilibrium via acid–base homeostasis and will not be materially adv... |
christianity | This is a good question, and this will be a long answer! I'll try to hit on all the major points, and if you have any more questions I can try to answer them later. Keep in mind, there are a lot of different Christians with a lot of different ideas, so other people might give different answers on some of these topics.
(I'll try to keep the language as something that a 5-year-old could understand, but I might slip up if I get carried away)
I'm not exactly sure what you mean by "Christian philosophy," so I'm going to skip that one right now. Could you tell me a little bit more about what you're looking for in that question so that I can answer it for you?
There are a lot of different groups of Christians, but you've mentioned some big ones, so we'll start with those!
Catholics are a really really big group of Christians. While they believe that Jesus came to die for our sins, they have some extra beliefs as well. Catholics teach that the Pope is the only human who can talk directly to God, and that everything that he teaches about the Bible is completely correct. A lot of their other beliefs come from the teachings of the Pope, and there's a ton of them - probably too many to explain here!
Protestants are another really big group of Christians, but they don't agree with the Catholics about the Pope or about who can talk to God. As a result, Protestants have a lot of different kinds of Protestants, because without a big boss figure to tell everybody exactly what to believe, different churches can take different positions on different minor beliefs. Even though every Protestant church has some basic belief similarities (about God, Jesus, being "saved" and the like), things such as which version of the Bible to use, how to baptize, and stuff like that can change from church to church.
Mormons are interesting, because many Catholics and Protestants will not call them Christians, but they call themselves Christians. Mormons believe that their founder received *extra* revelation from God, and that's why they have The Book of Mormon, The Pearl of Great Price, and Doctrines and Covenants. All of these were presented to the Mormon church by Joseph Smith as the word of God, and are treated as equal in truth to the Bible by Mormons.
Other Christian offshoots (such as Jehovah's Witnesses) have similar extra teachings, and even some Protestant churches (some hardline Seventh Day Adventists, many Christian Scientists) have teachings that they regard as just as important as the Bible. This is another topic that could take lots and lots of time and research to explore.
Jesus, according to Christian teaching, was *the* son of God. He came to earth, lived a life without ever doing anything wrong, and then was sacrificed. This was the only way to make sure that people could be forgiven of their sins forever, since only a perfect sacrifice can perfectly cover over the bad things that people do that make it so that they can't be with God. It's also important that Jesus came back from the dead, because this shows that he is bigger than death!
The Bible is meant to be taken very seriously, since Christians believe that it is the word of God; however, there are metaphors in the Bible all over the place. Which parts *exactly* are metaphors is a pretty debated topic, and that's not something I can really say, but even metaphors can be taken seriously! For example, Jesus said that if your right eye causes you to sin you should cut it out. Most people take this as a metaphorical statement (Jesus, according to them, didn't want people to self-mutilate), but it is a metaphor telling us to be sure that we take whatever steps we need in order to avoid sinning.
It took me a while to type this, so I may have gotten a little off-track or confusing. If I can elaborate a little more or clarify something that's still obscure, please let me know! | [
"Christianity is a monotheistic religion which developed out of Second Temple Judaism in the 1st century CE. It is founded on the life, teachings, death, and resurrection of Jesus Christ, and those who follow it are called Christians.\n",
"Christianity is based on the life and teachings of Jesus of Nazareth (1st ... |
How was "detective" work, or any crime-solving endeavor, carried out in the ancient world? | Quoting myself from a previous answer to a similar question:
It depends on what you mean by police.
In Ancient Greece, city-states had publicly owned slaves who acted as a police force. They kept order and controlled prisoners, but they didn't investigate crimes. Most crimes were considered a private matter so the citizens dealt with them themselves.
The city of Rome never had a real police force, though it had a force of men set up for the protection of each ward. These men were responsible more for public order and physical protection and had no role in criminal justice.
Most societies since then have had people who's duty was to "keep the peace" so to speak. One thing to keep in mind about criminal justice as a whole is that, for most of history, crimes were considered private matters between individuals. Eventually a new idea took hold in England; violating the King's Peace (through murder, theft, etc.) was not just a crime against an individual, but a crime against the whole kingdom. This brought about the prosecution of criminals even when no private citizen brought a case against them.
If, by police, you mean people who investigate crimes and arrest criminals, London's Bow Street Runners, founded in 1749, are regarded as the foundation of modern police. They were a formalization of the existing practice of 'thief-takers' - people who solved crimes for a fee. Prior to this, 'police' were basically only for keeping the peace in towns and cities; for example, the duties of Lieutenant General of Police, the foundation of the Paris police, were described as "ensuring the peace and quiet of the public and of private individuals, purging the city of what may cause disturbances, procuring abundance, and having each and everyone live according to their station and their duties". | [
"Criminal investigation is an ancient science that may have roots as far back as c. 1700 BCE in the writings of the Code of Hammurabi. In the code it is suggested that both the accuser and the accused had the right to present evidence they collected. In the modern era criminal investigations are most often done by ... |
how do motion-sickness bracelets work? | It's actually not known. Some think it's a placebo, some think there's something real about the acupressure.
They do work. _URL_0_ | [
"A hologram bracelet or energy bracelet is a small rubber wristband supposedly fitted with a hologram. Manufacturers have said supposedly that the holograms \"optimise the natural flow of energy around the body, and supposedly improve an athlete's strength, balance and flexibility\". Only anecdotal evidence support... |
i bought magic the gathering and i seriously cannot figure out how to play it. youtube video after video isn't helping. | Take a look at the sidebar over at /r/magictcg - it has lots of great resources for new players.
I also think that the best way to learn the game currently is to download the Magic Duels app on your phone/steam and play that. It introduces the rules to you slowly. | [
"Magic: The Gathering Online is a video game adaptation of \"\", utilizing the concept of a virtual economy in order to preserve the collectible aspect of the card game. It is played through an Internet service operated by Wizards of the Coast, which went live on June 24, 2002. Users can play the game or trade card... |
why can we feel sound waves, but not light waves? | You can feel light waves. Go stand outside on a bright day. It's a lot hotter in the sun than the shade, no? You just feel light in a different way than sound (usually, you feel infrared light the most, which feels like heat). | [
"Sound is one of the most important senses that the blind or visually impaired use in order to locate objects in their surroundings. A form of echolocation is used, similarly to that of a bat. Echolocation from a person's perspective is when the person uses sound waves generated from speech or other forms of noise ... |
In ancient Rome, what would happen if I needed my appendix out? | First, it would be important to look at the diet in Rome (understanding that Rome's history lasted a millennium and while many things changed, including medical practices, diet would have remained relatively unchanged). Grain and cereal was a large part of the diet and as a consequence so was fiber. Appendicitis is caused by the blockage of the appendix, often by stool (or in rare cases any inflammation such as cancer). Because of their high-fiber diet it would be very unlikely that many people developed appendicitis.
That being said, surgery was rarely practiced at all during the time. While medical practices did certainly advance throughout Rome's millennium. For most of the Republican period (~510 - 27 B.C.) the Hippocratic corpus is our most useful source (see the Hippocratic Oath in which it states "I will not use the knife, not even on sufferers from stone, but will withdraw in favor of such men as are engaged in this work"). During the Empire Galen tends to be our most useful source. While surgery and dissections became slightly more practiced (albeit more on animals than humans), the practice as a whole was comparatively non-existent.
TL;DR as unlikely as it would have been to develop appendicitis, if the miracle occurred, surgery would not be an option and the disease would likely be a death sentence. | [
"Appendicitis usually requires the removal of the inflamed appendix, in an appendectomy either by laparotomy or laparoscopy. Untreated, the appendix may rupture, leading to peritonitis, followed by shock, and, if still untreated, death.\n",
"Extirpation of the appendix, or appendectomy, is the standard treatment ... |
From our vantage point, is there anywhere in the univers that galaxies are still forming? | When we look really far away we do see galaxies forming. | [
"In 1734, philosopher Emanuel Swedenborg in his \"Principia\" speculated that there may be galaxies outside our own that are formed into galactic clusters that are minuscule parts of the universe which extends far beyond what we can see. These views \"are remarkably close to the present-day views of the cosmos.\"\n... |
how do small bands/record labels afford to send bands overseas to play live music? | Many american bands can, and do make FAR more money playing overseas than the do in the US, in fact, thats where they really make their money, in Asia and Europe. They play a ton of shows, and the clubs and festivals are willing to pay them much more than american counterparts. You might be surprised how certain bands or types of music in the US which are niche or small popularity, have a huge following in Europe and Asia.
As an example, Punk music in the 90s was a major thing like this.
While many punk bands had small followings in the US, and toured a lot, they were often not widely known to the US public, and shows were very cheap to go to in the US (which was a staple of the punk scene, shows were supposed to be cheap and dirty, and often small, there's very little money in that)
However, these same bands in Europe often enjoyed far more mainstream success, would play to large crowds both in festivals and not, and just take in piles of cash since they were much more popular there. This is where many 90s era punk bands actually made their money, from touring Europe, not record sales, or US tours. | [
"Bands that perform at a \"Live Radio Gig\" also receive multitrack recordings and mastered recordings of their set. This is a great initiative, as it gives local bands and artists access to professional recordings who otherwise may not be able to afford such services.\n",
"Several live music venues offer local i... |
Why did Ned Kelly's armour work against firearms, but medieval steel plate didn't? | The response to crossbows appears to have been to make better armour. When powerful crossbows were common, the best armour was crossbow-proofed (i.e., successfully tested against crossbows).
The response to firearms was first, do nothing, since crossbow-proof armour stopped (i.e., had a good chance of stopping) bullets from early/mid 16th century hand-held firearms, with muzzle energies typically below 1000J. See _URL_2_ for some past discussion by /u/WARitter of the penetration of armour by early firearms. For more, see Alan Williams, *The Knight and the Blast Furnace*, Brill, 2003.
Second, as guns improved, make the armour thicker (which also makes it heavier). Bullet-proof (i.e., successfully tested against bullets - typically pistol bullets) armour varied in thickness. Examples from about 3mm thick to about 9mm thick are found. See A. Williams, D. Edge, T. Atkins, "Bullet dents - "Proof marks" or battle damage", *Gladius* 26, 175-209 (2006) for examples.
Third, as the increase in thickness made the armour too heavy, get rid of the armour. The infantry was the first to discard armour. Cavalry retained bullet-proof armour for longer, and even when no longer wearing full armour, might still wear a bullet-proof breastplate. Siege engineers and specialist siege assault troops also retained heavy bullet-proof armour, in some case armour that would stop musket balls. These heavy siege armours were too heavy for regular wear on the battlefield, but in very high risk environments, could be useful.
Where does the Kelly Gang's armour fit into this? The armour was 4.5mm to 6mm thick (sources vary - /u/CChippy gives 3/16" in _URL_1_ and other sources often give 1/4"). Note that this is in the thickness range of bullet-proof armours of the 16th and 17th centuries.
Black powder pistols (see preceding link to past discussion of Kelly armour) of the type used against the armour typically had muzzle energies of about 300J. The rifles in use might have muzzle energies of about 1,500J, which would challenge the armour. Supposedly, the first version of the armour was found to not be strong enough, and thicker armour was made. From Williams, *The Knight and the Blast Furnace*, about 4.5mm of low-carbon steel armour (moderate quality) is required to stop about 1,500J.
The Kelly Gang were not facing muskets designed to penetrate armour on the battlefield (which could deliver in excess of 3,000J). This helped a lot. Even with this moderation of the threat they faced, their armour (at about the minimum thickness needed to stop bullets from the rifles they faced) was very heavy. Ned Kelly's armour was 44kg (97lb) (the other armours worn by the gang were lighter but less protective - Ned's armour had shoulder protectors and a rear apron, which the others lacked). This would have been rejected in the 17th century as too heavy for other than specialist siege/assault tasks.
In WW1, armour intended to stop bullets was used. One example, the [German brow plate, or *Stirnpanzer*](_URL_0_) was used to reinforce the German steel helmet to protect against bullets (the helmet, by itself, was *not* bulletproof). The Stirnpanzer was 5mm thick, about the same as the Kelly armours.
| [
"Modern tests and contemporary accounts agree therefore that well-made plate armour could protect against longbows. However, this did not necessarily make the longbow ineffective; thousands of longbowmen were deployed in the English victory at Agincourt against plate armoured French knights in 1415. Clifford Rogers... |
what's so bad about germany's economy? | Germany has a stronger export economy than most of the rest of Europe. This is perceived by some people as keeping the exchange rate of the Euro higher against international currencies than it should be; a lower cost Euro is seen as beneficial to countries like Spain and Greece which are heavily reliant on tourism to fuel their economy, they also happen to be in the most financial trouble. A slow deflation **edit: devaluation, not deflation** of the Euro would also ease the some of the financial pressure of Spain and Greece since it would effectively devalue the portion of their debt held by non Eu members, although this is a relatively small portion of their debts if I remember correctly.
There is a lot more to the issue but this is ELI5 so I won't dig any deeper, I also haven't proposed any counter arguments about why Germany's economy being strong is good for Greece and Spain, since that is more complex too.
tl:dr Germany's Economy is bad for Europe because it is indeed strong. | [
"Sinn has called the German economy a \"bazaar economy\" because the share of input from abroad in German industrial production is on the increase. At the same time he points out that this is not to be equated with a breaking off of value added in exports. Instead Germany has decimated its domestic sector via exces... |
Why isn't Rubidium yielded from U-235 Fission? | The atomic numbers of the fission fragments don't necessarily have to add up to the Z of the original nucleus. When fission occurs, the uranium nucleus splits into two heavy fission fragments, and some number of light particles, which could be protons, neutrons, alpha particles, or whatever.
So the Z of the two fragments doesn't necessarily have to sum to 92.
Also, as you mentioned, some of the fission fragments may decay very quickly after the fission, so by the time you actually measure the yields, they've decayed into other things. | [
"Uranium-235 fissions with low-energy thermal neutrons because the binding energy resulting from the absorption of a neutron is greater than the critical energy required for fission; therefore uranium-235 is a fissile material. By contrast, the binding energy released by uranium-238 absorbing a thermal neutron is l... |
Why doesn't fly spray kill humans? | Honestly it is a case of dose:body mass ratio. The weight of flies varies a lot based on side, type etc, but 10-20mg is common. When you spray an area even if the entire spray is only 1mg of active ingredient (the example on the wiki you posted is dichlorvos - an acetylcholinesterase inhibitor) enough would reach the fly to cause contractions in all of its muscles, stopping it from breathing and suffocating it.
A human has a much larger body, and once the drug is absorbed it enters our blood stream and is distributed around the body. Very little makes it to the places where it can have any serious effects. From normal use there simply isn't enough to make an impact on a human.
It is like comparing how a pipette might hold 1ml and look full (the fly is the pipette and the 1ml is the amount of drug to kill it), but put that 1ml into a pint glass and it is only 1/568th of the glass - A 2 litre bottle of soda and its only 1/2000th not anywhere close to being full. What is enough to fill one thing isn't necessarily enough to fill another… What is enough to kill one thing isn't necessarily enough to kill another.
Or a better analogy. A drop of poison in someones drink might kill them… put that same drop into an ocean someone is going to swim in, and watch as nothing happens. | [
"Some insecticides kill or harm other creatures in addition to those they are intended to kill. For example, birds may be poisoned when they eat food that was recently sprayed with insecticides or when they mistake an insecticide granule on the ground for food and eat it. Sprayed insecticide may drift from the area... |
How young did Venetians typically join the navy? Was there a difference between merchant and wartime fleets? | I am not sure what you mean by "Republican period" but I can give an answer for 15th around the "peak" of Venetian naval strength.
First to briefly describe the Venetian 'navy'. It consisted of state owned galleys (few if any sail ships were such state-owned) of usually two types: the merchant 'great' galleys and war 'light' galleys. The merchant galleys were used in Venetian convoy system for trading valuable goods to/from particular locations (Alexandria, Beirut, Flanders, Constantinople, etc) and in this system the galleys were "auctioned" for a particular voyage to a highest bidder. The person - or usually a partnership of several people - who won the auction could select whoever he wanted as a commander - called a *patron* - and he had to be a noble. War galleys - which served either as Guard - patrolling certain seas and locations - or stored on land and deployed when needed fir action, would have the commander - in this case called *sopracomito* - elected for one season directly by the State. To be eligible for election you had to be a noble, over thirty years old and usually of good standing and in particular good financial status as often they had to pay advances and other costs for crew and provisions from their own pocket (which could maybe be reimbursed later, but definitely financial liquidity was needed. These position was highly coveted and many noblemen did their best to secure a sopracomitoposition for themselves.
Now, this command post (patron / sopracomito) was basically the only officer rank on board that was noble. All the rest of the officer ranks were non-noble, and basically the ship was ran by non-nobles with the patron/sopracomito serving as overseer for trade/war matters. Now, it is not unreasonable to assume that in order to become a commander you had to have relevant experience. But how to get relevant experience, if no other officer posts were available for nobles? Well, one part of the solution was that the commander could bring aboard his retinue, like pages, servants, or just fellow passengers, and this was regularly used for commanders to 'accustom to the sea' their children or relatives or closely connected people of trust. Strictly speaking these people brought as retinue were not "in the Navy". They had no authority on the ship nor were they paid by the State. They were solely on the upkeep of the commander who had to pay all their expenses (or whatever other arrangement was made, but definitely not on official rolls).
The other option to serve as a noble on board was to be elected to be a 'bowman of the quarterdeck'. As opposed for ordinary bowmen who were non-noble, who counted 20-30 on board and were positioned on the benches with the rowers, the bowmen of the quarterdeck were noble and were stationed with the commander. There were initially four of them, then six, then eight for each galley. Their salaries and supplies were provided by the State/galley as part of the crew (they were naturally paid more). The secondary literature I am drawing from openly describes these positions as intended by the State to give young, poor, experiencing-hardship nobles a chance to get experience on the seas and opportunity to earn some money trading. They didn't have any offical say in running of the ship and were more intended as soldiers. However if a commander would die on duty, the next commander would come from the nobles on board. Initially the age minimum for bowmen was twenty, but it was lowered to eighteen, and exceptions were frequently granted for younger.
So how young the Venetians were when they started 'going to the sea'? Hard to say. One commander recorded he started taking his son along with him when the child was only four. Another noble records he went on his first voyage at fourteen under his uncle. But it's unclear if he went as a page/retinue or a paid bowmen. In each case that same noble was recorded to be going as bowmen on voyages at around twenty to twenty-two years old. From this few cases we might paint the picture that Venetians nobles started 'serving' (or being employed) on vessels at ages 14-20, with some frequently experiencing ship life and participating on voyages even younger if their parents/relatives would take them.
As a final note, I would just reference the non-noble ranks on board. The highest non-noble rank on board was a *comito* - usually translated as master. For all intents and purposes he was the main person in charge of ship for all matters naval. Although sopracomito could always overrule him. Second in charge was a *paron* who was also in charge of the bow (front) of the ship. They were aided by several men called *nochiero* who were lesser officers, and first step above oarsmen (where there would be junior and senior ones). All these officers could (and would) come from the oarsmen ranks and rise through ability. However all the officer positions on a galley were given through elections in Venice (and you needed to be a Venetian citizen, which could be gotten around by marrying a Venetian woman).
It was deemed beneficial to know how to read and write for junior officers, and for higher ranks you needed knowledge of mathematics and navigation. How young would you start? Hard to say, but for example Venetian conscription laws for oarsmen in time of war recruited from men aged twenty to sixty. As oarsmen were voluntary and often in short supply, younger men were often excepted. So again we may consider age of start being 16-20 (maybe as low as 14) if you were built well enough for the hard job of rowing. | [
"The Venetian navy had traditionally been a galley-based force. The first organized tactical formations of sailing ships—originally merchant vessels chartered for naval service—began being formed in the late 15th century. The position of \"Capitano delle Navi\" was established as the commander of the sailing squadr... |
why do so many people enjoy watching videos of pimples being popped? | I am going to throw one out there and say that it is hardwired into the brain like many other traits that make up out collection of self-preservation instincts.
Generally Dopamine is released as a reward for doing things beneficial to staying alive... Exercising, eating, childcare, pets and fire
(which is why we need fire and explosions on tv and films to like them more)
To stay healthy in caveman times; infections must not be allowed to take hold and you would be rewarded for avoiding such dangers. A cyst can become infected as can been seen in some of the horrific popping videos. A cleared out cyst can heal. NO cave people would clear infections if they were all repelled by such disgusting bodily gunge. those who could tolerate it survive infections. even within a tribe as long as there is someone who gets joy out of the bad jobs such as chiropracting (some hate it. some find it fascinating - same situation) or popping cysts; the welfare of the group improves.
So don't worry if you are the person who loves the videos of people apparently emptying toothpaste tubes out of their bodies under pressure. :/
Someones got to do it.... | [
"BULLET::::- In the April 2, 2008 episode of \"South Park\", \"Canada on Strike\", the boys post a viral video on \"YouToob\" (a fictional version of YouTube) of Butters performing \"What What (In the Butt)\".\n",
"A notable in-joke with Mac Hall revolves around an attention grabbing gag involving \"Digimon\". Ea... |
what's the fuss with purified water? | They're the same thing. Water is water. Some brands add (or, more often, don't bother to filter out) minerals that are good to you, but can often have a "dirty" taste. | [
"Purified water has many uses, largely in the production of medications, in science and engineering laboratories and industries, and is produced in a range of purities. It can be produced on site for immediate use or purchased in containers. Purified water in colloquial English can also refer to water which has bee... |
why would anyone want to limit or reduce the funding/laws towards the environment. | Several reasons:
- Personal profit and short-term thinking;
- Not believing that the problems are real;
- Believing that market forces will solve the problems (generally accompanied by a belief that government intervention is a bad thing in just about everything);
- An expectation that technology will solve the problems;
- Underestimating the extent of the environmental issues.
Normally, there's a combination of at least two of these reasons. | [
"An additional debate is to what extent environmental laws are fair to all regulated parties. For instance, researchers Preston Teeter and Jorgen Sandberg highlight how smaller organizations can often incur disproportionately larger costs as a result of environmental regulations, which can ultimately create an addi... |
How did indigenous cultures, European colonists, or pre-electricity South Americans understand the power of the Electric Eel? Did they understand it as the same phenomenon as lightning, or something else? | /u/robinthebum wrote about it at _URL_0_
This is not to discourage more discussion. I'd love to see more data, debate, and questions.
| [
"Long before any knowledge of electricity existed, people were aware of shocks from electric fish. Ancient Egyptian texts dating from 2750 BCE referred to these fish as the \"Thunderer of the Nile\", and described them as the \"protectors\" of all other fish. Electric fish were again reported millennia later by anc... |
Does heat radiation from metal radiate in all directions? | Such a complicated problem! _URL_0_ A simple quick answer for you is that since your pan is made up of two different materials, the thermal conductivity and amount of energy held by those materials is different and will be radiated off/exchanged at different rates and total amounts.
The heat capacity of aluminum is **0.89690 J/(g K)**
The heat capacity of Teflon (PTFE) is **1.4 J/(g K)**
The thermal conductivity of aluminum is **235 W/(m K)**
The thermal conductivity of PTFE is **0.25 W/(m K)**
The bottom of the pan probably had already lost a lot of its heat before you noticed the heat radiating off the top. | [
"When thermal radiation strikes an object, part will be reflected, part transmitted, and the rest absorbed. The fraction that is absorbed depends on the nature and color of the material. A thin material may transmit a lot. A light colored object may reflect much of the incident radiation and thus escape damage, lik... |
why are feminists opposed to the thin, scantily clad, large chested female characters in video games, but not the 6' feet tall male models with six pack abs on the covers of romance novels? | Feminists focus on *female* rights. They rarely touch on male perceptions. | [
"Men in games tend to be shown as muscular and big. For instance, men in video games have chests that are about 2 inches (6%) larger, heads that are about 13 inches bigger, waists that are 5 inches wider, and hips that are 7 inches wider, than in reality. They are often characterized as overtly aggressive and viole... |
Where did the Whites and Reds find the manpower and willing soldiers to engage in the Russian Civil War after the losses in World War I? | Good question. There are a couple of factors to take into account. The first thing is that much of the Russian Civil War was fought by fairly small forces. [According to PBS,](_URL_1_) Russia mobilized 12,000,000 soldiers during the First World War, lost 1,700,000 killed, 2,500,000 captured or MIA, and 4,950,000 wounded, a whopping casualty rate of 76.3%. Even acknowledging that some wounded would recover enough to fight again, that's a devastating count.
However, Russia's population was 166,000,000, in 1914, [according to Spartacus Educational](_URL_0_), so even given these devastating losses, there were still men of fighting age, including men involved in industry who had not been conscripted into the army. In fact, feeding Russia's population during the Civil War was a major problem, and more died from famine and disease than combat or political violence.
But you still certainly have a good point, and indeed the initial phase of the Russian Civil War was fought by small bands of soldiers and irregulars. Bruce Lockhart, a British diplomat sent to Moscow, estimated that the Bolshevik Army had 213,000 soldiers in 1918, split between those fighting the Whites in Siberia, in the Caucasus and Central Asia, and screening the German Army in the west.
Most of these were ill-disciplined worker's militias, deserters, Chinese laborers, and Austro-Hungarian (mostly Hungarian) POWs who joined out of conviction or to avoid starvation in abandoned prison camps. The backbone was formed from 23,000 committed Communist Lithuanian riflemen, who were rushed from front to front to deal with crises. So while there were still troops, the numbers were greatly reduced from the Russian Amy's wartime strength.
The Whites had even worse problems recruiting soldiers. General Denikin's Volunteer Army, the main White force in South Russia, set up recruiting offices in the Don, but only had around three thousand soldiers for most of the year, plus several thousands Don Cossacks. The vast majority of officers preferred not to get involved. The fact that the Volunteers often beat much larger Red forces is attributable to the fact that most of the them, even in the rank-and-file, were officers, and they were much better disciplined than their opponents. In North Russia, the British-backed government in Archangel never raised considerable numbers of troops (and those they did often deserted en masse), while the backbone of the Siberian Whites in 1918 was the 70,000-strong Czech Legion. So, we can see that only small numbers of men actually fought during the first phase of the war, on very vast fronts, and that the best fighters were not Russians, but foreign soldiers.
The war kicked up a notch in 1919, and both sides were forced to conscript soldiers. The Reds also conscripted former officers into the Red Army and coerced them to fight by holding their families as hostages. However the majority of the conscript soldiers on both sides were not very interesting in fighting, and tended to desert when it suited them. White armies converged Red Russia in 1919 from three sides, reaching their high-water mark in 1919, but the Reds possessed Russia's populous, industrial center, while the Whites were confined to the peripheries in the Baltic, Ukraine, and Siberia. Thus, the Reds could raise far more troops, and with the help of internal lines could focus on one threat at a time. While the Reds could replace losses, the Whites had a much harder time doing so. In Siberia, the Reds usually conscripted prisoners that they took, but the Whites shot theirs or stripped them and left them to freeze to death, rather than enlisting them. By the autumn of 1919 every major White threat had been defeated and the war was as good as over, but it continued for several more years.
So, I hope that answers your question. In short, the major points:
1.) Russia took huge losses in WWI, but still had a massive population.
2.) The war was fought by relatively small numbers of soldiers.
3.) Both sides did have trouble finding soldiers (especially willing ones), and resorted to conscription or enlisting prisoners by force.
Sources:
Richard Pipes, *Russia Under the Bolshevik Regime*
Mr. Lockhart to Mr. Balfour, "Memorandum on the Internal Situation in Russia", *British Documents on Foreign Affairs*, Doc. 5.
John Bradley, *The Allied Intervention in Russia*
Jonathan Smele, *Civil War in Siberia: The Anti-Bolshevik Government of Admiral Kolchak*
| [
"The Whites and the Reds fought the Russian Civil War from November 1917 until 1921, and isolated battles continued in the Far East until 1923. The White Army—aided by the Allied forces (Triple Entente) from countries such as Japan, the United Kingdom, France, Italy and the United States and (sometimes) the Central... |
How does buoyancy work on a molecular level? | "Kinetic theory" may be the term you're looking for, if that helps you in future googling.
So, "pressure" is just the molecules smacking against each other, and applying forces to each other when they collide. The other main force they're feeling is gravity.
If these forces don't cancel out, then there will be a net force, and the fluid will move. So if you have some bunch of particles, and gravity is pulling them down faster than the collisions are pushing them up, then they will move downwards. If there's already other molecules down there, the fluid will start to get denser and hotter.
Density is just the number of particles you have in a space, and temperature is just how fast they're going. So denser and hotter means more collisions, and stronger collisions. So denser and hotter things have higher pressure.
Note that these are *local* things. Pressure comes from how hot and dense some part of a fluid is - the total amount of fluid or whatever doesn't directly matter. All that matters is how hot and dense it is.
The other part is that *uniform* pressure doesn't apply a force. You need a *pressure gradient*. That is, if you're getting pushed evenly on all sides, you don't get pushed anywhere. But if you get pushed more from the bottom than from the top, then you will get pushed up.
So what happens in a fluid is that, if it's not in equilibrium with gravity, it will start to collapse down and compress itself, and you end up with a gradient of density and/or temperature, which means there's a gradient of pressure, which means that it can support itself against gravity.
And if it can support itself against gravity, it can support other things against gravity too: and that's buoyancy. | [
"Buoyant density centrifugation (also isopycnic centrifugation or equilibrium density-gradient centrifugation) uses the concept of buoyancy to separate molecules in solution by their differences in density.\n",
"Buoyancy force is the defined as the force exerted on the body or an object when inserted in a fluid. ... |
I want to read 12 history books in one year to know "all the things", what should be on the list? | Take Rothbard off the list. He was more of a propagandist than a historian. | [
"BULLET::::- This is the oldest book in the collection. Roughly 12 other libraries in the world hold this volume; six in the US (including two copies held by Harvard), three in France and three in Germany. It is thought to be the first book to ever mention, although it is in passing, fish or fishing in the New Worl... |
how are movies like the parent trap made when one actor plays multiple roles and their faces are seen together in the same shot? | One way of doing it is to shoot the scene twice without moving the camera. The first time, they shoot the scene when the actor plays the first role, the second time the second role. These two versions of the scene are then blended over each other.
Another version uses blue-screen in which one of the takes (or both) are shot in front of a blue canvas (or green), which is then replaced by a real background.
In these cases, the actor never touches the other character because it's, well, impossible. There is, however, techniques that allow this. One way is to compose the picture in a way that cuts the arm (usually around the elbow), and another actor is touching the character. The blend-over scene fades out the fact that there's just a "magic hand" there. | [
"In some productions, a scene calls for two characters in the same shot, both of whom are portrayed by a single actor. A body double can portray one of the characters, while the credited actor plays the other, thus enabling both characters to appear simultaneously on camera. An example of this is the identical cous... |
Why did the Scandinavian Norsemen write runes? | Despite their seemingly mundane and formulaic inscriptions, the raising of runestones in Late Viking-Age Sweden, particularly around Uppland, was a fashionable and calculated effort by (mostly) affluent locals to display their wealth, status and allegiance. The primarily Christian iconography and inscriptions of the stones reveal a changing society, in which it may have been beneficial for an individual or clan to publicly advertise their new-found conversion and have others follow their example.
A few good sources on all things to do with these inscriptions are Michael Barnes' *Runes: A Handbook*, and Judith Jesch' *Ships and Men in the Late Viking Age: The Vocabulary of Runic Inscriptions and Skaldic Verse* | [
"Unlike Proto-Norse, which was written with the Elder Futhark, runic Old Norse was originally written with the Younger Futhark, which only had 16 letters. Because of the limited number of runes, several runes were used for different sounds, and the distinction between long and short vowels wasn't retained in writin... |
why is white pride racist, when no other "colour" pride is considered racist? | In general, the issue here is that when people say they have "white" pride, they are saying "I am proud that I am not black." as opposed to people having pride in their specific heritage. No one has a problem with people having pride in being Irish, German, Italian, Polish. Those get celebrated.
But "white" just means that you are of European descent. In practice, it gets used by white supremacists.
Now, you're going, "Yes, but black people have black pride!" And that's because their heritage and history were destroyed by slavery. They can't trace their ancestry back to a specific culture or country. So all they have is the common background of being of African-descent. They use "Black pride" to show solidarity in the face of adversity.
No one uses "white pride" in a positive manner. It is used to show superiority over black people, not a celebration of a rich cultural history. | [
"Political and social scientists commonly argue that the idea of \"white pride\" is an attempt to provide a clean or more palatable public face for white supremacy or white separatism and that it is an appeal to a larger audience in hopes of inciting more widespread racial violence. According to Joseph T. Roy of th... |
Why has Country Music remained so white? What cultural and industry forces kept the genre that so willingly borrowed from blues, gospel, norteño, and mariachi so completely dominated by white artists and tied to white identity? | The answer to that goes back to the early days of the recording industry. You're right, country, blues, gospel and southern gospel artists all borrow relentlessly from each other, and that tradition goes back to the 1800's before the genres got clearly separated out (I can't speak to mariachi or norteno as I haven't studied those). As I understand it, in the early 1900's as the recording industry was coming online, "race" records and "hillbilly" records were created as niche markets - race records selling to lower class African Americans, hillbilly records selling to lower class white Americans. The musics sounded very similar at that point, but it was the marketing of the artists that separated them out by race. Now whites were more than happy to listen to black music, and vice versa, but it was how they were marketed that created the initial distinction between the genres, which became country and blues, respectively, and once distinguished they became statements of identity. Their religious counterparts, gospel and southern gospel, have a slightly different history, as they both emerged from hymns but southern gospel also was influenced by rural singing conventions. Each of those genres borrowed from each other, but were more clearly separated even from the beginning because Sunday morning is the most segregated hour of the week in the U.S. - much less opportunity for artists to share music, although once the Pentecostal movement got going in the early 1900's, that allowed for a lot more crossover since it started out inter-racial.
Why it's remained that way is simply that music is a very powerful means of creating a sense of personal and group identity. Music, of all kinds, acts physically (resonance of sounds in the body), emotionally (connection of sounds to emotional states), and textually (in the lyrics) to reinforce particular social narratives and ways of being in the world. Once country music was successfully labeled white by the marketing arm of the recording industry, that took on a life of it's own thanks to the racial dynamics of American culture. It becomes a self perpetuating cycle where whiteness becomes a significant feature of country music, and vice versa, as a shortcut for distinguishing between and reinforcing the social and racial class structures. Food, clothing, and other cultural items work much the same way.
Some Sources:
* Don Cusic, The Sound of Light: A History of Gospel Music
* Michael Harris, The rise of gospel blues: the music of Thomas Andrew Dorsey in the urban church
* Cecelia Tiichi, High lonesome: the American culture of country music
* Sarah Thornton, Club cultures: music, media, and subcultural capital
* Benjamin Filene, Romancing the folk: public memory & American roots music
* James Goff, Close harmony: a history of southern gospel
* Robert Darden, People Get Ready!: a history of black gospel from Africa through present
| [
"The musical forms and styles that are now considered the blues as well as modern country music arose in the same regions of the southern United States during the 19th century. Recorded blues and country music can be found as far back as the 1920s, when the record industry created the marketing categories \"race mu... |
During WWII, which Red Army unit was considered "elite"? Which was its most successful, and why? | The Red Army was very vast within the Second World War. Therefore there was a few different elite units. The major ones of these we're called Guard units. When an army proved itself as a well trained fighting force, they would get a Guard title attached to their title. One of the notable we're the 2nd Guard Army which participated in the Battle of Stalingrad as part of Operation Uranus which led to the circling of the German Sixth army. | [
"At the start of World War II the Red Army was notorious for its poor battlefield quality because a large number of its newly appointed commanders lacked initiative and skill. Kreizer was among a few senior officers who prepared his troops adequately for the requirements of the modern mobile war. In July 1941 Kreiz... |
how do kickstarter payments work? what prevents the receiver from just running away with the money? | To my knowledge, nothing stops them. In fact there have been numerous complaints of people never getting what they order off of Kickstarter. It's very much buyer beware. | [
"Direct Payments are intended to empower service users by allowing them control and choice over the services they use to meet their needs. Each person on the scheme is given an amount of money to be managed by themselves, possibly with the aid of others such as family or an external advocacy organisation. This mone... |
why do we have to put oil in our cars, why can't we use another liquid like water? | Water boils at typical engine temperatures, isn't viscous enough to actually lubricate very well, and is highly corrosive to unprotected metal surfaces. It's about the worst common liquid you could use for this job.
The oil is there to coat and lubricate all the moving parts of the engine so they don't corrode or grind. Engines get very hot during operation and the metal is easily oxidized so you need a liquid that won't boil off, is very chemically inert, and is thick enough to stay on surfaces when they're moving very quickly.
Motor oil checks all three of those boxes for a very low cost. | [
"Oil needs to be changed because it gets contaminated with combustion by-products that accumulate at about the same rate regardless of oil type. Some vehicles require synthetic; therefore, check your vehicle's owner manual to see what is recommended.\n",
"Residual fuel oil is less useful because it is so viscous ... |
why doesn't the blood in raw meat clot (as far as i can tell)? | Because it isn't blood. It's myoglobin. Red meats, such as beef, are composed of quite a bit of water. This water, mixed with a protein called myoglobin, ends up comprising most of that red liquid. | [
"Blood is the most important byproduct of slaughtering. It consists predominantly of protein and water, and is sometimes called \"liquid meat\" because its composition is similar to that of lean meat. Blood collected hygienically can be used for human consumption, otherwise it is converted to blood meal. Special fr... |
where does weight actually go when one is losing it? how can i go to sleep weighing 202 and wake up weighing 199? | > how does it actually leave your body?
Primarily through your breath. You breath in (some) O2, and breathe out (some) CO2. The extra carbon in there comes from your body "burning" sugars, converting sugar + O2 into H2O and CO2, which you breathe/sweat/urinate out, as appropriate.
Fun fact, plants use a similar process in reverse. That is, the solid bulk of trees is made up (mostly) from carbon in the air. Thus trees grow from material in the air, not material in the ground as many people seem to think. | [
"While health professionals almost unanimously agree that if an individual is already getting 8 hours of sleep, then another half hour won't make them lose weight; however, in cases where a person is used to getting 5 hours of sleep per night and they start getting 7–8 hours, it is common to see them start to shed ... |
how do people get away with murder in the courtrooms, even if it was obvious that they did it? | > even if it was obvious that they did it?
Being "obvious" isn't enough. The prosecution has to **prove** that they did it, beyond a reasonable doubt. Something as wishy-washy as "it's obvious" would be a *terrible* basis for a legal system. | [
"Since the early 19th century, American courts have tried over 400 murders in which the victim's body had not been found; Bonie's case would have been the first in the Bronx. \"It's like running a 100-meter race when the criminal gets to start at the 20-meter mark,\" a former federal prosecutor told the \"Times\". ... |
When nations/people moved (e.g. Turks, Anglo-Saxons), did the entire population move or just the leaders/army? | It's a matter of much debate, and historians views have varied greatly over the years. Once, pretty much all historians thought that the migrations in fifth-century Europe were all great movements of people. Now, however, many believe that many of the barbarian groups were primarily military forces. Overall, it varied massively. For instance, the Belgic settlement in late Iron Age southern Britain seems to have only been the movement of the political and cultural elite, but the early migrations of Goths into the Roman Empire definitely included a high proportion of non-combatants (this is attested by written sources and art). Moreover, there also would have been migrations such as the Anglo-Saxon ones, that included a lot of non-combatants even though if was not a case of entire populations on the move. Quite simply, it varied a great deal and there was something of a spectrum; it wasn't just a case of army or nation, sometimes it was a bit of both. The Norman conquest of England might seem like a classic example of just the elite and army migrating, but it led to a lot of traders, craftsmen and even some peasants moving from the continent to Britain. | [
"During the period of Military Frontier, mass migrations of the population went on all the time in both directions and in several waves. First fleeing away from Turks, then those who collaborated with the Turks were fleeing after their fall, and in the second direction people fleeing from the vengeance of those arr... |
if i'm far enough from the ground holding my glasses, the lens will cast a shadow even though they are clear. if i move up like a foot, the lens shadow becomes more and more transparent. why? | First, shadows. We *should* all know by now that this is caused by blocking light, places where no light reaches a surface are darker places where the light can reach are brighter.
So in the case of when your glasses cast a shadow it means less light is able to reach the surface. The reason why this happens even though your glasses are 'clear' is called refraction^1
In it's simplest form; If you think of light as a line when light passes through certain objects (which obviously have to be opaque otherwise it would create a shadow). The material it passes through can change the direction of our light. Due to this the light would hit another area then one would expect when it would go straight forward, as we are used to with the regular shadows from for example the sun.
Now if you have the surface of your glasses; they are not completely flat the surface is bend and thicker in some areas than others. That in combination with the refraction makes the light leaving the other side of your glasses not travel in the same direction as it did before it hit the glasses. Therefor at the right distance no light will reach certain areas because the light has been redirected.
One of the most common examples of the same principle is a kindergarden science experiment where you use a magnifying glass to focus sunlight to burn a hole in a piece of paper. [See this illustration!](_URL_0_). Now moving away from the heat creation in this experiment the direction of light is the same principle. Also as illustrated at the focal point (where the paper burns) is where all the light is.
But around it there is a shadow because all the light has been redirected.
Now if you move it up far enough, enough light from outside sources would reduce the strength of the shadow because of outside light sources crossing over.
* ^1 [Wikipedia Refraction](_URL_1_) | [
"Real lenses do not focus all rays perfectly, so that even at best focus, a point is imaged as a spot rather than a point. The smallest such spot that a lens can produce is often referred to as the \"circle of least confusion\".\n",
"If instead the lens is held very close to the eye and the object is placed close... |
how many time does radioactivity takes to disappear ? | Never.
Radioactivity never disappears, it simply gets weaker with time. This is due to half life. A half life is a set amount of time during which half of the radioactive material decays. After decay, it is probably harmless. After 1 half life, half of the original material remains, after 2, a fourth, after 3, an eighth. It gets smaller but never quite hits zero. | [
"This relationship between the half-life and the decay constant shows that highly radioactive substances are quickly spent, while those that radiate weakly endure longer. Half-lives of known radionuclides vary widely, from more than 10 years, such as for the very nearly stable nuclide Bi, to 10 seconds for highly u... |
where are the colors that a human can't see? is my wall secretly another color? | The electromagnetic spectrum of light is very, very long. We call colours the wavelengths that we can see with our eye. But there is a lot more in the electromagnetic spectrum than the range between 390 and 700 nm. The wavelength is a particular feature of the wave, imagine a sinusoidal wave (a nice smooth curve that starts at 0, goes up to 1, down to 0, continues to -1, returns to 0). The distance between the first and last 0 is called the wavelength. It can be a nanometer (Xrays), several hundreds of nanometers (visible light), it can be several meters (radio). And I'm talking real distance. As in the wave starts at the wall and ends 1 meter later (and then it repeats itself). Probably you've heard of frequency, frequency is the inverse of the wavelength. Long wavelength, low frequency; short wavelength, high frequency.
The first colour we see is red (700 nm), before that we call light infra-red. Then we see all the colours of the rainbow ending with violet (390 nm), beyond that we call light ultra-violet. A few species can see a bit in the ultra-violet range. It is believed that insects choose certain flowers because of their pattern in the UV, and not by the bright visible colours that we see.
In total, you would have (in increasing wavelength):
gamma rays - X rays - UV - visible light - infrared - television and radio waves.
Edit: your wall totally emits infrared radiation, because it is at a certain temperature. It will emit less than you, unless your wall is crazy hot. This principle is why nocturnal vision cameras work. It is electromagnetic radiation, yes, but it's not a "colour". | [
"The spectrum does not contain all the colors that the human eyes and brain can distinguish. Unsaturated colors such as pink, or purple variations like magenta, for example, are absent because they can only be made from a mix of multiple wavelengths. Colors containing only one wavelength are also called pure colors... |
Can a historian please tell me the date when Lincoln said the following quote? | Assuming you do mean "struggle" and not "stubble" (which is actually pretty funny in itself), a simple google search within quotation marks brings up this:
_URL_0_
Illinois House of Representatives, December 20th, 1839. The quotation is in the last paragraph. I don't know how reputable that is, but it gives you a place and date that you can verify or discount as well as a title (*The Writings of Abraham Lincoln* vol. 1). Happy hunting. | [
"Lincoln spoke at the Gettysburg battlefield cemetery on November 19, 1863. Defying his prediction that \"the world will little note, nor long remember what we say here\", the Address became the most quoted speech in American history.\n",
"Not even the day's primary speech, Lincoln's carefully crafted address cam... |
why do dogs love peanut butter so much? | Sweet, salty. Why else? | [
"In March 2016, Murray's photos of dogs eating peanut butter were featured in a Daily Mirror article. His photo series of dogs eating peanut butter quickly went viral. Over the next few months, Murray's photography was featured by \"Huffington Post, Elle Magazine, Today, Bark Post, Mashable, San Francisco Chronicle... |
why do companies trademark simple words that other companies use anyway? | A trademark is more than just the words, it is the entire presentation of the logo. While other restaurants can still use the description of "Mild", they cannot use the specific font and color scheme of the trademarked packets. Other companies can call their products "cola" but they can't use the red and white curly font without Coke going after them. | [
"Many trademarks are adapted from words or symbols that are common to the culture, as Apple, Inc. using a trademark that is based upon the apple. Other trademarks are invented by the mark owner (such as Kodak) and have no common use until introduced by the owner. Courts have recognized that ownership of a trademark... |
difference between hypoxemia and hypoxia | Hypoxemia is having low oxygen content in your blood, while hypoxia is moreso the effects felt from not having enough oxygen. So in a sense hypoxemia can cause hypoxia | [
"\"Hypoxemia\" refers to the low level of oxygen in blood, and the more general term \"hypoxia\" is an abnormally low oxygen content in any tissue or organ, or the body as a whole. Hypoxemia can cause hypoxia (hypoxemic hypoxia), but hypoxia can also occur via other mechanisms, such as anemia.\n",
"Hypoxemia refe... |
why do we refer to animals' colors not as the color they actually are? | I have absolutely no clue what you are talking about. I started to have small inkling, but then, where do animals come into play? | [
"Some animals are colored purely incidentally because their blood contains pigments. For example, amphibians like the olm that live in caves may be largely colorless as color has no function in that environment, but they show some red because of the haem pigment in their red blood cells, needed to carry oxygen. The... |
why does climate change mean that climates will become more extreme, rather than just changing? | Some areas may become less extreme. But in any place the environment and our use of it is built around a certain climate. In places that are regularly flooded, agriculture on the floodplains relies on the regular flooding to provide water and silt for nutrients. Loss of regular flooding would have a very severe effect. In areas that do not regularly flood, people build houses on the river banks, and regularly flooding there would be devastating.
Climate change is going to increase the amount of heat in the atmosphere, and this will increase the amount of water evaporated, and the amount of energy available to create storms. This is the reasoning behind the predictions of more extreme weather. | [
"Because the climate system has large thermal inertia, it can take centuries for the climate to fully adjust. While record-breaking years attract considerable public interest, individual years are less significant than the overall trend. Global surface temperature is subject to short-term fluctuations that overlay ... |
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