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If photons travel at the speed of light, that means the time lapse from the photons perspective is either absent absent or infinitely small. So does that mean, when I turn on a flashlight and point it at a wall, the photons were both created and at the wall at the same time? | Light moves at c relative to all frames of reference.
That means, that there is no frame of reference, relative to which light is at rest.
We also know, that time is relative, and changes as a function of relative velocity. Thus we would need to be able to define a valid rest frame of a photon in order to make a vali... | [
"The solution to this paradox is that superluminal velocities can be observed because no actual particles or information are traveling from object 1 to object 2. The transverse velocity of the beam along the path in the sky between the objects has an apparent speed greater than light, but this represents separate p... |
I have heard things like "none of the apostles actually met Jesus" ... Where or how would you get that kind of information? | No one says the Apostles never met Jesus, but the authors of the Gospels were not Apostles.
First, it should be stated that none of the authors of the Gospels ever claim to have met Jesus or to have known anyone else who met Jesus. They were all originally anonymous works, and the titles and authorship traditions were... | [
"In the Synoptic Gospels, Jesus is said to have approached the area near the city, but without entering the city itself. Jesus, while in this area, asked his closest disciples who they thought he was. Accounts of their answers, including the Confession of Peter, are found in the Synoptic Gospels of Matthew, Mark, a... |
How historically accurate is the book "The Killer Angels ". | The book is a historical novel first and foremost. And it sacrifices historical fact for fictional convenience. One small example is the location of 20 Maine on the third day. Shaara placed them just behind the center of Cemetery Ridge so that the primary "hero" on the Union side, Chamberlain, can narrate Pickett's cha... | [
"The Better Angels is a 1979 thriller novel by Charles McCarry. It was poorly received at the time of its release; its premise of terrorists using passenger planes as instruments of destruction was considered too implausible to suspend one's disbelief. It was the basis of the comedic 1982 Richard Brooks film \"Wron... |
Why was Edward I Plantagenet not given the regnal number 'III'? | hi! you may be interested in these posts
* [Why did the regnal numbers for the Kingdom of England reset after 1066 but not reset upon creation of the Kingdom of Great Britain?](_URL_0_) - /u/Algernon_Asimov and /u/Skittles_87 explain that regnal numbers were introduced in England by the Normans
* [Why was Edward Plan... | [
"The House of Plantagenet takes its name from Geoffrey Plantagenet, Count of Anjou, husband of the Empress Matilda and father of Henry II. The name Plantagenet itself was unknown as a family name \"per se\" until Richard of York adopted it as his family name in the 15th century. It has since been retroactively appl... |
Why were the Ancient Greeks so intrigued by the idea of female warriors (Amazons)? | You're certainly right that Amazons featured very prominently in Ancient Greek art and mythology. Everyone from Achilles to Alexander the Great is said to have battled Amazons; Theseus, the mythical king of Athens, supposedly married one. Amazons appear all through the iconographic record, in sculpture, and in literary... | [
"BULLET::::- The Amazons (in Greek, ) were a mythical and ancient nation of female warriors. Herodotus placed them in a region bordering Scythia in Sarmatia. The histories and legends in Greek mythology may be inspired by warrior women among the Sarmatians.\n",
"Speculation that the idea of Amazons contains a cor... |
What is the relationship of the electron to the photon, in terms of electromagnetism being a single force? | Electrons have mass, photons don't. For this reason, electrons can settle down to a very low speed and sit there as part of an atom. Without mass, photons must always travel at the universal speed limit in vacuum. Photons cannot slow down and stop and thereby become part of a stable localized structure (although photon... | [
"Maxwell's equations of electromagnetism relate the electric and magnetic fields to each other and to the motions of electric charges. The standard equations provide for electric charges, but they posit no magnetic charges. Except for this difference, the equations are symmetric under the interchange of the electri... |
Which Brands Had Name Recognition for Shoppers in the Eastern Bloc? | I don't know which (if any) product from Eastern Bloc was popular in the West, but I can give you a few examples of such brands that were popular in Poland:
- Belarus was well known for their "Minsk" (how creative...) refrigerators - they were loud, they were heavy, but insanely reliable. My grandma was using one up u... | [
"The roots of consumerism started as early as the 1930s when in 1935 each Soviet Republic capital city established a model department store. The department stores acted as representatives of Soviet economic success. Under Khrushchev the retail sectors gained prevalence as Soviet department stores GUM (department st... |
how images shared through social media like facebook become so pixelated and full of artifacts? | Social media site tend to downgrade images to save themselves on bandwidth. If someone uploads their 5mb images from a 16 megapixel camera, Facebook is going to shrink it.
For sharing memes and such, someone probably saw it somewhere, saved it, and uploaded it *again* to a different social media, where it might get sh... | [
"Sharing images via mobile phones has become popular. Several networks and applications have sprung up offering capabilities to share captured photos directly from mobile phones to social networks. The most prominent of these is Instagram, which has quickly become the dominant image sharing-centric social network w... |
what would happen if a presidential candidate won the election but decided not to take the job? | If they resigned after being sworn in the VP becomes president until the term is completed. The former VP could run for their own term or simply allow others to run and not opt to take the office again.
If the person quit after the election but prior to being sworn in it's not clear what would happen. | [
"If the winner of an election were not running in the first place, then obviously someone else would have won instead. Similarly, if a candidate gets \"added\" to an election, it becomes possible for the new candidate to win. If these are the only cases in which a change in the candidate set leads to a different el... |
The syntax politics of "tribe" in historical descriptions of indigenous groups (primarily African and North American at early-ish stages of colonial contact). | I wrote about this a few times, [in this Monday Methods](_URL_1_)
[this podcast episode](_URL_0_) also contains a bibliography about the scholarship surrounding tribe and ethnicity in Africa.
> the connotations behind using the term "tribe" to discuss groups of indigenous peoples at the stage of colonial contact (mo... | [
"In his 1975 study, \"The Notion of the Tribe\", anthropologist Morton H. Fried provided numerous examples of tribes that encompassed members who spoke different languages and practiced different rituals, or who shared languages and rituals with members of other tribes. Similarly, he provided examples of tribes in ... |
the hubble telescope was launched in 1990. since our technology has advanced tremendously since then, wouldn't it be advantageous to send a more advanced telescope up there? | > wouldn't it be advantageous to send a more advanced telescope up there?
NASA is working on it. The [James Webb Space telesope](_URL_0_) is slated to launch in 2018. | [
"NASA managers and engineers declared the mission a complete success. The completion of all the major objectives, as well as some that were not considered vital, upgraded the Hubble telescope to its most technologically advanced state since its launch nineteen years before and made it more powerful. The upgrades he... |
Why did the U.S. engage in a strategy of island hopping in the Pacific during World War II - as opposed to simply blockading the Island of Japan? | A military requires an enormous amount of resources to operate, and to simply leave the navy off the coast of Japan indefinitely without possibility of resupply would not have been possible. What happens when a ship takes critical damage, but the nearest friendly base is in Australia or Hawaii? Many of the islands atta... | [
"In order to capture the islands from Japan, the United States military employed a \"leapfrogging\" strategy which involved conducting amphibious assaults on selected Japanese island fortresses, subjecting some to air attack only and entirely skipping over others. This strategy caused the Japanese Empire to lose co... |
what would happen if china just said "ok, the yuan is worth whatever you say it is, market." | First of all there is a misconception amongst laypeople that *any country* truly lets their currency float with the daily whims of the market. The US Federal Reserve, the European Central Bank, and as far as I know most of their equivalents for other currencies, all set currency value targets that they try to maintain ... | [
"However, China explicitly stated the Chinese Yuan was not discussed. Despite coming under heavy pressure to let their currency appreciate the Chinese appeared to be standing their ground. Despite the refusal to discuss this the currency fell.\n",
"BULLET::::- June 19 – China announces it will raise the yuan agai... |
- what ad and bc mean in terms of time. also, is there a difference between bc and bce? | AD means Anno Domini - "In the year of our Lord." AD 0 is meant to indicate the year of birth for Jesus of Nazareth, and counts upwards from that point.
BC means "Before Christ" - years before the birth of Jesus.
(Fun fact: Most historians now think that Jesus was not born in 0 AD, but 4 BC.)
CE and BCE mean "Com... | [
"Note that BC and BCE refer to the same time period. BCE is an abbreviation for Before Common Era, and BC for Before Christ. AD is Anno Domini, and CE is Common Era. This is done in order to standardize time periods across the world (ISO 8601).\n",
"The 1st century BC, also known as the last century BC, started o... |
How much light does moon reflect back to earth? | This is actually a common homework problem for atmospheric radiation classes. The answer is [about 2 x 10^12 Watts](_URL_1_). This is a bit less than the [total power consumed by the USA](_URL_0_); seemingly not an insignificant amount! However, it is **100,000 times less powerful than the contribution from the Sun**.
... | [
"Solar radiation (or sunlight) is the energy Earth receives from the Sun. Earth also emits radiation back into space, but at longer wavelengths that we cannot see. Part of the incoming and emitted radiation is absorbed or reflected by the atmosphere. In May 2017, glints of light, seen as twinkling from an orbiting ... |
Is the light from the sun mostly incandescence or a byproduct of fusion? | Outside of some faint gamma ray emissions, light from the sun is effectively blackbody radiation. (The spectrum looks like [this](_URL_0_).) Steps in the proton-proton chain (the dominant fusion process in the sun) release gamma rays, but light from the core scatters off of the interior of the sun in a random walk last... | [
"The release of energy with the fusion of light elements is due to the interplay of two opposing forces: the nuclear force, which combines together protons and neutrons, and the Coulomb force, which causes protons to repel each other. Protons are positively charged and repel each other by the Coulomb force, but the... |
how do courses work in university? [uk] | University was quite a long time ago for me, but I doubt the structure has changed that much... you'll probably have a core component of classes (which are mandatory) and a series of optional routes to take depending on how you want to specialize within your discipline.
You might get a taster of all of these options ... | [
"This is a list of colleges in the United Kingdom offering higher education courses. Many of the colleges below are \"listed bodies\" that are authorised to offer courses leading to a degree from a UK university or other body with degree-awarding powers. Others may offer non-degree higher education courses such as ... |
central banks, and why some people think they are bad | We first need to start at what a normal bank does.
Let's say you've saved up $100. You're very proud of yourself, and you should be! You've done a great job saving money. However, you need a place to keep it. You'd *also* like to see this money grow over time.
Meanwhile, your friend Bob just came up with a great idea... | [
"Certain groups of people, like Libertarians, believe central banking is an incompetent cartel that does very little to prevent recessions. Milton Friedman for example has claimed the FED contributed to worsening the Great Depression by artificially keeping interest rates too low and then suddenly shocking the syst... |
What is Ben Franklin describing in this passage? | So one of the chronic problems of the Colonies was lack of cash money. While rich in land, crops, timber and other assets, most colonies also had great demand for imported goods and few liquid assets. Whatever gold and silver coins were present in the colony tended to leave it quickly to buy imported goods, which wer... | [
"BULLET::::- Benjamin Franklin (from Boston, USA) is an influential author, politician, scientist, inventor, statesman, soldier, and diplomat. In the first book, while commissioned by the United States to Paris, he hid a Clue located under the Paris Catacombs. It started the rivalry between him and his own branch. ... |
when a macro-object breaks, such as a wooden board chopped by a karate student, what is happening to the object at a molecular level as it is breaking? | Either the force or heat generated from the karate chop is great enough to break up the bonds holding the atoms together. | [
"Breaking, the discipline of destroying inanimate materials such as wooden boards, bats, ice or bricks is a feature common to several Asian martial arts. It can be seen in its oldest form within some branches of Chinese Kung Fu such as Iron Shirt Chi Gung, where iron bars are smashed off the bare heads of martial a... |
why dick cheney is a "war criminal", and worse than other bush-admin politicians who also pushed for war. | People consider Dick Cheney a war criminal, because there was no evidence of weapons of mass destruction in Iraq. This was the whole basis for entering and bombing Iraq. Also, Dick Cheney was the Chair and CEO of [Halliburton](_URL_0_) which is the largest US military defense contractor. No conflict of interest there | [
"McClellan harshly criticizes the Bush administration over its Iraq war-making campaign, though he writes in detail about his personal admiration for President Bush. He accuses Bush of \"self-deception\" and of maintaining a \"permanent campaign approach\" to governing, rather than making the best choices. McClella... |
Check this out: Ask marine archaeologists questions live as they excavate a 19th century wreck in the gulf of mexico! | Removed. You're required to ask the mods before posting this type of thing. | [
"Moore has worked as a maritime archaeologist exploring a shipwreck believed to be part of the 1622 Spanish treasure fleet sunk near the Dry Tortugas. The wreck, located in 1332' (406m) of water, yielded olive jars, copper, gold, silver, glass and other cultural artifacts. He also served as project archaeologist fo... |
the half-life game series | Step 1: buy the first game on Steam.
Step 2: play the first game on Steam.
Step 3: repeat for the second game and subsequent episodes
Step 4: join the HL3 circlejerk | [
"Half-Life (stylized HλLF-LIFE) is a series of first-person shooter games developed and published by Valve. The major installments feature protagonist Gordon Freeman, a physicist who battles an alien invasion. \"Half-Life\" (1998) and \"Half-Life 2\" (2004) are full-length games, while \"\" (2006) and \"\" (2007) a... |
Does the Moon's gravity have a tidal effect on bodies of liquid that are underground? | In smaller, confined aquafers, it has been shown that tides have [very little influence](_URL_3_).
In larger, unconfined aquafers, [tides do effect](_URL_1_) [the water](_URL_2_) [table](_URL_0_). | [
"Atmospheric tides are also produced through the gravitational effects of the Moon. \"Lunar (gravitational) tides\" are much weaker than \"solar (thermal) tides\" and are generated by the motion of the Earth's oceans (caused by the Moon) and to a lesser extent the effect of the Moon's gravitational attraction on th... |
If the moon disappeared, would we physically notice it? | Yes. Tides are also caused by the Sun, to some effect, the tides would be weakened considerably rather than nonexistent. Apart from that small correction, and a small change in the Earth's motion due to conservation of momentum, the only thing I can think of is the lack of seeing it at night. I apologize, however, for ... | [
"A lunar occultation occurs when the Moon, moving along its orbital path, passes in front of a star or other celestial object, as seen by an observer (normally on the Earth). Light from the occulted object is blocked by the moon and a perceptible shadow of the moon is cast onto the ground if that ground is in night... |
How does research on factors causing/preventing Cancer work? | A lot of these articles are correlation studies that I personally don't really pay attention to. The amount your chances increase is so small, that most of the time it isn't even worth worrying about it.
There are articles that say 'factor X' increases your chances of cancer and here is how. These research articles ar... | [
"Cancer research is an area of biology where growth curve analysis plays an important role. In many types of cancer, the rate at which tumors shrink following chemotherapy is related to the rate of tumor growth before treatment. Tumors that grow rapidly are generally more sensitive to the toxic effects that convent... |
why are humans so prone to creating and following routines? | In general, if you find a way to solve a problem, repeating the steps to solve that problem again will often end up in similar results. If you are satisfied with the results, then there is no good reason to pick an alternative method for solving that problem. This is valuable for highly important tasks, and it doesn'... | [
"Routines have various organisational roles – first, they coordinate and control. Coordination is when the simultaneity of action is enabled after which it leads to regularity, consistency and predictability and it can easily change into control. Second, routines also reflect a truce in that they are developed on a... |
How is an actual memory different from a memory of an imagination or fantasy? | Lie detectors, atleast modern ones, do not determine whether your memories are correct or not but rather it's a form of pseudoscience of measuring how your body reacts to both external and internal stimuli.
An "actual" memory can be, in completely technicality, no different than a memory of an imagination or fantasy i... | [
"\"Memory\" uses many of H. P. Lovecraft's common images and ideas, such as relics of the deep past and things \"without name\". Also, his fondness for vast, monolithic ruins (a favourite with many other Cthulhu and horror writers) is evident in the intricate description found in the page-long story.\n",
"In line... |
why does the taste and texture of whiskey changes when you keep a shot in your mouth for some time ie 30 seconds, before you swallow it? | I would imagine its not whiskey that changes texture but delicate skin in your mouth and tongue react to being bathed in strong alcohol. | [
"Chill filtering prevents the whisky from becoming hazy when in the bottle, when served, when chilled, or when water or ice is added, as well as precluding sedimentation from occurring in the bottles. It works by reducing the temperature sufficiently so that some fatty acids, proteins and esters (created during the... |
Why did Imperial Russia treat Finland especially well when compared to other territory they conquered? | There were a number of reasons. First, Finland was much smaller than Poland and not traditionally hostile to Russia (Russia could make a plausible case that it had freed the Finns from Swedish imperialism and left them better off). In fact, there was considerable precedent for this in the Russian Empire with the Baltic... | [
"The Emperors of Russia found Finnish nobility a nicely co-operative group of useful people in general, and entrusted much of the administration to locals. This was one of reasons why the autonomy of the country was so well established.\n",
"In 1899, the Russian Empire initiated a policy of integration through th... |
why do we have to eat and sleep? | I don't know but, I really wish:
- we didn't have to sleep
- we didn't have to poop
Sadly, if we didn't have to sleep, asshole bosses of the world would expect us to work 18 hours a day. So, the truthiness is:
- I wish *I* didn't have to sleep | [
"Sleep eating involves consuming food while asleep. These sleep eating disorders are more often than not induced for stress related reasons. Another major cause of this sleep eating subtype of sleepwalking is sleep medication, such as Ambien for example (Mayo Clinic). There are a few others, but Ambien is a more wi... |
if i want to gain weight, is eating late at night bad for you? | No. The time you eat is not relevant. If you are looking to gain weight then you need to consume more calories than you burn each day. Hopefully you supplement that with exercise so that you put at least some of the weight on as muscle instead of just fat. | [
"\"\"We are having a particularly hungry period and [I] can quite truthfully say that our mouths water, and that we 'slaver' as dogs do before meals. Some of us find it advisable to rise slowly after lying down, as due to malnutrition, any rapid movement is apt to cause dizziness or even a black-out ... one morning... |
France behind the German trenches. | Hi there, you might be interested in [this answer](_URL_0_), which I wrote to a similar question. | [
"Trenches were still dug but were no longer intended to be fought from, being used for shelter during quiet periods, for the movement of reinforcements and supplies, as rallying points and decoys. Before an attack, the garrison tried to move forwards into shell-holes, to avoid Allied artillery-fire and surprise att... |
how can it be proven that a piece of intellectual property belongs to its owner? | If its a copyrightable work you can register it with the US Copyright Office. If its a patentable invention you *need* to register it with the US Patent Office.
Other methods, like mailing it to yourself or having it notarized are trivial to fake and do absolutely nothing to prove ownership. | [
"Ownership consists of the relationship between an individual and an object. This relationship can be very strong such that the individual considers their possessions as extensions of themselves. One may claim to own an object by (1) paying attention to it, (2) being in physical contact with it, (3) linking it with... |
why doesn't reddit have its own image sharing option? why are most images posted from _url_0_? | technicaly it does, imgur was created by a redditor for easy sharing on reddit. | [
"Flickr provides both private and public image storage. A user uploading an image can set privacy controls that determine who can view the image. A photo can be flagged as either public or private. Private images are visible by default only to the uploader, but they can also be marked as viewable by friends and/or ... |
I found two versions of the same photo from 1930s Germany from school books. Would anybody have information about it? | Hi. The picture is showing Michael Siegel a Jewish lawyer/attorney from Munich and was taken in March 1933. Mr. Siegel was working for a client who has been transported to Dachau. When he went to the police headquarters to inquiry about that he was beaten up by SA men and then they paraded him through the city. On the ... | [
"BULLET::::- McBride, Patrizia. \"Narrative Resemblance: The Production Of Truth In The Modernist Photobook Of Weimar Germany.\" \"New German Critique: An Interdisciplinary Journal of German Studies\" 115.(2012): 169–197.\n",
"His most recent book, continuing his research into the era of World War II, was publish... |
Why can some medication be given in tablet form but other need to be administered by injection such as vaccines? | It depends on what you are ingesting, most medications are chemicals some can be absorbed by the stomach and others are broken down by your stomach acid. Vaccines are different from your conventional medicine, vaccines are basically weak or dead viruses, bacteria of a certain disease that you inject in your self to imm... | [
"The compressed tablet is the most popular dosage form in use today. About two-thirds of all prescriptions are dispensed as solid dosage forms, and half of these are compressed tablets. A tablet can be formulated to deliver an accurate dosage to a specific site; it is usually taken orally, but can be administered s... |
In an Autopsy, what part of a human body smells the worst? | The large intestine of someone with C. diff. | [
"The smell of death, while rumored or imagined to be distinct and recognizable, has relatively little scientific research. In 2004, the gasses released during decomposition began to be catalogued by the University of Tennessee Anthropological Research Facility. However, for practical application of this research, w... |
What was the role of musket infantry in sieges? How were their weapons used, both by defenders and attackers? | During the Early Modern period, siege warfare was a highly technical and methodical exercise in theory, though in practice any number of things could transpire. The main roles for infantry were manning the lines of circum- and contra-vellation to protect the pioneers and gunners, manning the covered way, assaulting en... | [
"Unlike the cannons or mortars used in Western warfare during Middle Ages and the 16th century, which required heavy iron balls, hwachas fired arrows which were thin and light, making it an easy-to-maneuver siege weapon.\n",
"During siege actions, Chinese deployed rattan shields and iron pavises (large shields), ... |
why does salt turn 'invisible' once dissolved in water? | The bonds between the Na and Cl in the salt crystals are broken, the Na and Cl become + and - ions which get surrounded by water ( H2O). These ions are so very small that they don’t interact with light passing through the water so the water remains clear.
Some things dissolve in water but actually if you looked real... | [
"A substance may dissociate without necessarily producing ions. As an example, the molecules of table sugar dissociate in water (sugar is dissolved) but exist as intact neutral entities. Another subtle event is the dissociation of sodium chloride (table salt) into sodium and chlorine ions. Although it may seem as a... |
when you use your muscles to lift things for a long enough period of time, what is happening to them when they can't lift anything anymore? | A build up of lactic acid, combined with a lack of fuel to run those muscles. The fuel issue subsides with rest and recovery from the exercise in question. This is why you can burn out your muscles, wait 4 minutes, and then use those muscles again.
The fuel in this case is ATP, someone please correct me if I'm wrong... | [
"Also emphasized when near exhaustion in order to further exhaust the muscle or muscles exercised: doing static holds for periods of time, and negative reps (lowering the weight). This will stimulate further growth and strength because muscles are weakest in positive/contracting movements (sometimes referred to as ... |
why is it that when we do something, we have to tell someone about it? | While I'm no psychologist, I would have to guess that the event of a new (or irregular) experience is always something that sits on the top of your mind. If you feel the need or desire to talk to someone you begin to talk about the first thing that comes to mind. For me, I just changed calipers, rotors and pads on my w... | [
"When using other people's things, one must clearly ask. If one doesn't ask, then it is stealing. When other people borrow things from you, if you have them don't be stingy. When I speak, honesty is important. Deceitful words and lies must not be tolerated. When still unsure of what you saw, do not say it. When sti... |
why are marvel comics based in real world locations and dc comics based in fictional ones based on real world locations? | DC started the tradition in 1938 with Superman and Metropolis. Superman was originally going to be a newspaper strip, and there was concern that if they set it in a specific city (Cleveland was their first attempt), it wouldn't sell as well elsewhere. From there, the tradition that DC Superheroes had fictional cities a... | [
"In July 2014, Johns described the series as \"the most faithful DC Comics adaptation ever... We've incorporated almost everything of the mythology into it and added a new backstory with S.T.A.R. Labs.\" In October 2014, Johns explained that DC's approach to their films and television series would be different to M... |
What happened to the USSR's Atomic Arsenal after it dissolved? | It was inherited by the Russian Federation. The remaining weapons in other Soviet states — Belarus, Ukraine, and Kazakhstan — were transferred to Russia after some negotiations. | [
"All Soviet ministries, with the exception of the Ministry of Defense and the Ministry of Atomic Energy, were abolished or taken over by the Russian Federation on 20 December 1991. The Soviet Ministry of Atomic Energy was abolished in January 1992, replaced by the Ministry for Atomic Energy of the Russian Federatio... |
the process of digestion and how stuff goes from tummy to liver to kidneys to colon. | im not an expert, but i think i can throw out a very basic idea of it...
when you eat food, it takes a pretty straightforward path from your mouth down your throat into your stomach. It sits in the stomach for a while digesting, and at some point is pushed into and through your small intestines. After approx 23 feet... | [
"Digestion occurs in the intestine, with the caecum producing further digestive enzymes. An additional tube, called the siphon, runs beside much of the intestine, opening into it at both ends. It may be involved in resorption of water from food.\n",
"The major part of digestion takes place in the small intestine.... |
Long term consequences of living in elevated oxygen areas? | For humans, the only problem with slightly higher oxygen concentrations is that it could result in lower red blood cell counts over time. This is not a direct problem per-say, but it could make adjusting to lower oxygen levels slightly more difficult.
The amount of oxygen produced by this process would be very small ... | [
"Oxygen levels will fluctuate throughout the year; this is due to seasonal changes in nutrient availability, solar radiation, and water column stratification (layers of water of different density, temperature, and salinity). Low oxygen conditions are at their worst in the late summer, after several months of limite... |
Which method(s) did early human civilizations use to extract ore and turn it into tools and weapons? | The Toaster Project described how a guy attempted to create a toaster from scratch. He tried to get everything straight from the source - metal from ore, minerals from deposits, plastic from oil - the whole bit.
He had a really difficult time with pretty much everything. Metal was a bear because the only way to re... | [
"Certain metals can be recovered from their ores by simply heating the rocks in a fire: notably tin, lead and (at a higher temperature) copper. This process is known as smelting. The first evidence of this extractive metallurgy dates from the 6th and 5th millennia BC, and was found in the archaeological sites of Ma... |
How did philosophers like Plato, Aristotle and Socrates make a living? | I cannot say about western philosophers, so instead I will say about Chinese and Muslim philosophers instead. The Chinese philosophers that flourished during Spring and Autumn period acted like modern day consultants, they traveled from one state to another, offering services to the rulers. The services could be anythi... | [
"Some scholars regarded Aristotle as a Socratic thinker. Aristotle's ethics builds upon earlier Greek thought, particularly that of his teacher Plato and Plato's teacher, Socrates. While Socrates left no written works, and Plato wrote dialogues and a few letters, Aristotle wrote treatises in which he sets forth phi... |
how does terahertz radiation work? | It works just like any other form of radiation, like microwaves or radio waves, just a different frequency/wavelength.
The issue with treahertz (the treahertz gap) is that there aren't any cost effective technologies to use the band as optics aren't sensitive enough and electronics aren't fast enough. It's very power-... | [
"Terahertz radiation is a region of the spectrum between far infrared and microwaves. Until recently, the range was rarely studied and few sources existed for microwave energy at the high end of the band (sub-millimeter waves or so-called terahertz waves), but applications such as imaging and communications are now... |
Why do the eyes of some blinded people lack pigmentation? | You might be thinking of cataracts, which can cause blindness.
[Image](_URL_0_) | [
"The human eye normally produces enough pigment to color the iris blue, green or brown and lend opacity to the eye. In photographs, those with albinism are more likely to demonstrate \"red eye\", due to the red of the retina being visible through the iris. Lack of pigment in the eyes also results in problems with v... |
How is Zero-G functionally different from the absence of gravity? | Freefall doesn't get rid of tidal gravitational fields. The difference in Earth's gravitational field between the front and back of the ship could be detected with precise instruments, and would be absent in intergalactic space. | [
"Zero-g is an alternative term for weightlessness and holds for instance in a freely falling lift. Zero-g is subtly different from the complete absence of gravity, something which is impossible due to the presence of gravity everywhere in the universe. \"Zero-gravity\" may also be used to mean effective weightlessn... |
Where does Hawking Radiation fall on the EM Spectrum? | Well it depends very much on the size of the black hole. The temperature of the black hole is inversely proportional to its mass ([source](_URL_0_)), and the wavelength of light coming from it then depends on this temperature. So the bigger the black hole, the lower the temperature, and thus ~~lower~~ higher the wavele... | [
"In the coordinate system of a distant stationary observer, Hawking radiation tends to be described as a quantum-mechanical particle-pair production effect (involving virtual particles), but for stationary observers hovering nearer to the hole, the effect is supposed to look like a purely conventional radiation eff... |
why do we frequently end words with 'y' when we're talking with children, i.e. mommy, daddy, doggy, kitty? also, is this just an english language thing, or are there similar instances of this in other languages? | In linguistics, that's called a diminutive. In English, it's typically done with an "ee" sound (usually spelled with a y or ie).
In Spanish, for instance, the diminutive is represented with the suffix "ito" or "ita" (so señorita literally means "little miss"). | [
"Infants begin to understand words such as \"Mommy\", \"Daddy\", \"hands\" and \"feet\" when they are approximately 6 months old. Initially, these words refer to their own mother or father or hands or feet. Infants begin to produce their first words when they are approximately one year old. Infants' first words are... |
how does the measuring of electricity work? | Voltage is the electric potential. Thats more like the pressure than anything else. Voltage hurts but doesn't really harm you. This is because our nerves are quite literally run with electricity.
Amps is the current, the speed of flow of electricity. A small current into your heart will kill you, but you need a good a... | [
"Electrical measurements are the methods, devices and calculations used to measure electrical quantities. Measurement of electrical quantities may be done to measure electrical parameters of a system. Using transducers, physical properties such as temperature, pressure, flow, force, and many others can be converted... |
Fantasy stories often star an 'adventurer', a sort of lone mercenary wandering across a european medieval setting. Are there any examples of such people? Not large groups like Vikings, Normans or steppe people, just individuals. | A lot of examples would not be famous at the time and thus wouldny have documentary evidence.
One example i can think of is Harald Hadrada, a Viking warrior who fought around scandinavia then Ukraine, and fought for the Byzantine empire around the mediteranean area, and, ended up dying in battle in England while try... | [
"Jason Heller, of The A.V. Club, notes that the group of adventurers are \"led by a half-elf fighter named Tanis, a man torn between his human and elven heritages, because of course he would have to be—who become enmeshed in a battle against the forces of evil striving to take over the dual-mooned, pseudo-medieval ... |
How do scientists know how much carbon there was originally in a sample when carbon dating? I understand that they take advantage of the half-life to the age of the object, but don’t they also need to know much was originally there? Also, what is the uncertainty on these measurements? | Great question. Radiocarbon dating measures the ratio of Carbon-14 (^(14)C), which is unstable with a half-life of 5730 ± 40 years, to Carbon-12, which is very stable.
^(14)C is always being produced in the atmosphere by cosmic rays.
A cosmic ray smashes into an atom in the atmosphere, which decays, emitting a neut... | [
"The precision of a dating method depends in part on the half-life of the radioactive isotope involved. For instance, carbon-14 has a half-life of 5,730 years. After an organism has been dead for 60,000 years, so little carbon-14 is left that accurate dating cannot be established. On the other hand, the concentrati... |
Keeping up manpower in WWI | Germany was pretty well tapped out by 1918, the shift of c. 500 000 men from the Eastern Front having only temporarily mitigated a manpower crisis that had plagued the German Army since the Somme. Britain made it through the initial manpower crisis of 1918 just fine, but was looking at difficult times ahead in 1919; Fr... | [
"During and after the First World War, casualties amongst young men resulted in an acute shortage of manpower in the workforce. The need to re-establish these men in open employment facilitated the growth of OT in the treatment of those with physical disabilities. Curative workshops were opened within military hosp... |
What happened to all the children who survived the Nazi concentration camps in the days following their liberation? Was there a system of sorts that either reunited them with surviving members of their own family or placed them in a new family? | the absolute majority of children who went to nazi concentration camps were sent straight into the gas chambers but I've some family stories tangentially related with that question of yours:
* my grandmother had her family *shot* but she was "adopted" by her neighbours. When the Soviet troops arrived she became a nurs... | [
"Their two daughters, aged 9 and 14, who had already endured the trauma of losing their parents, were then forcibly separated from each other as they were sent off to different Nazi re-education camps. Nazi officials then sent Rosa Stallbaumer to the Third Reich's concentration camp at Auschwitz, ensuring that she ... |
if I go with nearly the speed of light in outer space, how long would it take for me to stop moving due to friction? | Short answer: you won't. Ever.
Long answer: At that speed, and with gas as thing as it is in space, you don't really get friction in the normal sense. Really, you get individual particles smashing into the front of your spacecraft like bullets.
Secondly, galaxies only cover a small fraction of the sky, and because of... | [
"Rather than exceeding the speed of light within a local reference frame, a spacecraft would traverse distances by contracting space in front of it and expanding space behind it, resulting in effective faster-than-light travel. Objects cannot accelerate to the speed of light within normal spacetime; instead, the Al... |
why is the rhetoric surrounding pro-choice focused on “woman’s body, woman’s choice”? shouldn’t the arguments be on whether a fetus constitutes a life or not? | Whether the fetus constitutes a life or not, I actually agree with the bodily autonomy argument.
For the same reason that a living person cannot and should not be forced to donate organs/blood/tissue to save another person, the fetus being considered "alive" still wouldn't be entitled to the use of a woman's body agai... | [
"Abortion discourse in the United States is often explained in terms of being \"pro-choice,\" i.e. in favor of abortion rights, or \"pro-life,\" i.e. favoring fetal development and protection of the life of the \"unborn child\" and opposing abortion. Reproductive justice challenges the pro-choice/pro-life dichotomy... |
If tooth decay is just caused by the bacteria feeding and producing acid, would a person that just used listerine have the same dental health as a person that brushed without flossing? | Nope. Brushing dislodges food in a manner that simply swishing mouthwash never could. Food stuck in the natural nooks and crannies of your teeth provides the perfect shelter, diet, and breeding ground for those bacteria | [
"Tooth decay (dental caries) has become a pronounced health hazard associated with the consumption of sugars, especially sucrose. Oral bacteria such as \"Streptococcus mutans\" live in dental plaque and metabolize \"any\" sugars (not just sucrose, but also glucose, lactose, fructose, and cooked starches) into lacti... |
Is it possible to have multiple infections that weaken each other until the immune system can eliminate them? | In the olden days, [malaria was used as a treatment for tertiary syphilis](_URL_0_) because of the prolonged high fevers. The malaria was treated with quinine. Not the best treatment, but it was what they did before penicillin was discovered. | [
"Even if the host does develop antibodies, protection might not be adequate; immunity might develop too slowly to be effective in time, the antibodies might not disable the pathogen completely, or there might be multiple strains of the pathogen, not all of which are equally susceptible to the immune reaction. Howev... |
is justin trudeau good for canada | That's not really a question with an answer.
He made quite a few promises about restoring the openness of canadian government and improving the tone of our political discourse, he's already taken some encouraging steps in that regard (like holding one of the first real Prime Ministerial press conferences in years),... | [
"A liberal, Trudeau has led the Liberal Party of Canada in one general election, in 2015, which he won by defeating then-Prime Minister Stephen Harper and the Conservative Party of Canada. He has been prime minister since November 4, 2015.\n",
"By the end of the campaign, Trudeau was unquestionably the most popul... |
whats the difference between shaving your face and shaving your head? | The head is hard and bumpy. The face is not very flat, but the fat and muscle underneath allow it to conform to the razor better.
The razor probably works for both, but by marketing for separate parts they can sell more razors. | [
"Head shaving is the practice of shaving the hair from a person's head. At different times and places people have shaved all or part of their heads for very diverse reasons including practicality, convenience, low maintenance, fashion, style, religion, culture, and aesthetics.\n",
"Head-shaving is a part of some ... |
Can we forget things by learning "too much"? | You remember things better when you reinforce those memories. If you specialize in a certain field, then you're constantly reinforcing the original or similar information. As a generalist, you don't focus as much on the same information, so you don't reinforce it as much.
You aren't pushing out the old information. Yo... | [
"Retrieval failure provides another explanation for why we forget learned information. According to this theory, we forget information because it is inaccessible in long-term memory stores. Access to this information depends on retrieval cues, and the absence of these cues causes difficulties in recalling retained ... |
- what's happening when you can see the emotion in someone's eyes? | Part of it is that our eyes are pretty constantly moving even in very tiny ways. When you're dead, they stop. Also, for some people, when they're thinking heavily, or lost in thought, their eyes unfocus and they're not actively looking at anything. So when someone has their eyes open, but not actively using them (wh... | [
"Patients shown images on their blind side of people expressing emotions correctly guessed the emotion most of the time. The movement of facial muscles used in smiling and frowning were measured and reacted in ways that matched the kind of emotion in the unseen image. Therefore, the emotions were recognized without... |
why do young earth creationists cite the lack of transitional fossils as a reason to doubt evolution even though there are plenty of transitional fossils in the fossil record? | They don't care that they exist.
The most important concept here is that you cannot logic someone out of a position that they did not logic their way into. These kinds of people have an idea of what they want the fossil record to say before they even start investigating. Then they only see evidence that supports t... | [
"Although transitional fossils elucidate the evolutionary transition of one life-form to another, they only exemplify snapshots of this process. Due to the special circumstances required for preservation of living beings, only a very small percentage of all life-forms that ever have existed can be expected to be di... |
what's happening with the eu banning memes? will it pass, has it already? what does it mean for the internet as a whole? | They are not directly banning memes.
They are creating a law that will have lots of negative effects if it is put into force, and the people who wanted to campaign against the bad law had to come up with some catchy way to convicne the general public how bad this would be.
They went though the long list of potentiall... | [
"The EU has invested in many filtering projects such as NETprotect I and II, ICRAsafe and the PRINCIP programme. It has been stated that self-censorship Internet users impose upon themselves is probably the most serious threat to Internet freedom. Mass surveillance and fear of private communications being made publ... |
Temperature of the Brain Linked to Thought Capability? | Circuits need to be kept cool because the electricity flowing through very tiny components creates lots of heat.
The brain, like the rest of the body, operates optimally at around 37 C. This temperature is optimal for the enzymes that drive cellular processes, including firing synapses. | [
"The balance between the releases of neuropeptides derived from the biological clock and from a metabolic sensory organ as the arcuate nucleus, are essential for an adequate temperature control. These observations show that brain areas involved in circadian and metabolic functions of the body need to interact to pr... |
Is it possible that we've brought microbial life with us to Mars? | The [Office of Planetary Protection](_URL_0_) exists to prevent planetary cross-contamination. | [
"There is ample evidence to suggest that Mars once offered habitable conditions for microbial life. It is therefore possible that microbial life may have existed on Mars, although no evidence has been found.\n",
"The question of microbial life on Mars remains unresolved. Nonetheless, on April 12, 2012, an interna... |
Why does putting something in a zip-loc bag keep it fresh, if there's still plenty of air in the bag? | > Why does putting something in a zip-loc bag keep it fresh, if there's still plenty of air in the bag?
If properly sealed, the oxygen in the ziploc may not be enough to oxidize the food past equilibrium, though this process will occur. Remember that the oxygen is consumed as it oxidizes.
As for canned foods, most ... | [
"The bag is an airtight reservoir that holds air and regulates its flow via arm pressure, allowing the player to maintain continuous even sound. The player keeps the bag inflated by blowing air into it through a blowpipe or pumping air into it with a bellows. Materials used for bags vary widely, but the most common... |
Why is the Vicksburg campaign considered one of the greatest offensive campaigns in modern military history? | Words like "greatest" and other superlatives are more appropriate for a debate at a bar (or in fairness to White, a NY times bestseller) than an academic discussion of history. They are a harmless rhetorical flourish that doesn't contain much information.
The Vicksburg campaign is quite interesting to many military h... | [
"The campaign consisted of many important naval operations, troop maneuvers, failed initiatives, and eleven distinct battles from December 26, 1862, to July 4, 1863. Military historians divide the campaign into two formal phases: operations against Vicksburg (December 1862 – January 1863) and Grant's operations aga... |
Methods of ear protection for those operating muskets etc | As a former reenactor with bad ears, I empathize. As far as I can tell, soldiers, then and now, have not used hearing protection on anything like a regular basis. Soldiers (and their officers) tend to be more concerned about surviving the immediate firefight or battle, which requires the ability to hear orders and comm... | [
"Users should follow the same rules as if handling a conventional firearm (see gun safety), but given the frequently improvised materials and construction used in spudguns, it is particularly important for the user to use basic ear and eye protection when operating a spudgun.\n",
"Whether indoors or outdoors, all... |
why is voltage used as opposed to current to warn people away from electric hazards? | because the adage "it's amps that kill not volts" is a stupid one. You could grab the posts of a 12V car battery *capable* of pushing out 1,000 amps and it won't do anything because it's only 12V. The amount of amps pushed across your body is directly related to how many volts are behind it. Amps = Voltage/Resistanc... | [
"Electrical safety is a system of organizational measures and technical means to prevent harmful and dangerous effects on workers from electric current, electric arc, electromagnetic field and static electricity.\n",
"The mainstream scientific evidence suggests that low-power, low-frequency, electromagnetic radia... |
why do most cosmetics/lotions etc have a shelf life? | In general the "shelf life" is the period during which a producer is confident that, provided proper handling, the product will perform to the standard they expect.
This doesn't mean that something like bottled water will instantly spoil beyond that date or shampoo will suddenly melt your head off. It just means that ... | [
"Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or just no longer on a supermarket shelf (unfit for sale, but not yet unfit for use). It... |
How are fireworks “programed” to set off certain explosions at certain times? | there are several methods, but a very common one is to use electronic ignition. the fireworks are set up on an array that has certain ones go off at certain times. Another is to use an igniter fuse that ones by one burns each rocket off, and is delayed using different fuses to change the timing.
After the fuse is lit... | [
"Fireworks or \"flares\" are launched onto the screen, where they hover for a period of time before disappearing. The player controls the direction of a \"guideline\" ray extending from the circular cursor which allows a flare along the ray to be \"captured\". The goal is to string together three or more flares of ... |
Does the Transit method limit our ability to detect planets further out from their star? | Yes! And this bias is something that we do have to take into account. Different methods for detecting planets have different biases, so we always have to account for that if we're trying to make statements about the population of planets as a whole.
The transit method works best when the planet is big enough to create... | [
"The transit method of discovering exoplanets relies upon carefully monitoring the brightness of a star. If a planet is present and crosses the line of sight between Earth and the star, the star will dim at a regular interval by an amount that depends upon the radius of the transiting planet. In order to measure th... |
if oj simpson was found not guilty of murder, how was ron goldman's family able to sue him for $20 million? | In most western judicial systems, there are two major "tracks," for lack of a better term, that courts handle: criminal matters, and civil matters.
Criminal matters are where you've committed a crime, and the government wants to punish you for it. Let's say you drove drunk, and you hit me. The government is trying to... | [
"Simpson was tried for the murders of both Brown and Goldman. In October 1995, after a public trial that lasted nearly nine months, he was acquitted. In a 1997 civil trial, a jury found him liable for the wrongful death of Goldman and awarded $19.5 million in damages to his family. Simpson was subsequently jailed f... |
What do we know about the scholarly works of the Roman Emperor Claudius? | To my knowledge exactly zero fragments of any of Claudius' writings survive. No author quotes Claudius at all and I am unaware of any papyrus finds. The Packhard Humanities Project, which catalogs Latin authors pretty well, has no page on him and collects no fragments of his. | [
"Cluvius Rufus was an important historian whose writing and testimony, though now lost, certainly shaped modern understanding of first century Rome. He was a contemporary of Caligula, Claudius, and Nero, but little is known of the extent of his work except that it related to events during the reign of these emperor... |
When a boat floats over water, does the force on the ground directly underneath it become greater? | It spreads the load over the entire affectable water surface. All of the bridge, and probably a fair amount of river upstream and downstream from the bridge. The water reacts to the boat being placed in the stream by rising, then spreading out as far as possible. This increases the depth, and thus pressure, of the wate... | [
"Ships float in the water at a level where mass of the displaced water equals the mass of the vessel, such that the downwards force of gravity equals the upward force of buoyancy. As a vessel is lowered into the water its weight remains constant but the corresponding weight of water displaced by its hull increases.... |
Can you give me a rundown on how New Orleans went from being one of America's cities to one of the country's biggest embarrassments by the end of the 20th century? | I'm on my phone so I can't answer in much detail, and I'm also not an expert. I hope what I write here will be interesting but it can't possibly be complete. Like all history, the story of New Orleans is nuanced and complicated and includes many factors other than what I will discuss. but I'll say what comes to mind. F... | [
"In the year of 1836 (history of New Orleans) New Orleans was the fourth largest city in the United States, the largest city away from the Atlantic seaboard, as well as the largest in the South. The city had become the wealthiest and third-most populous city in the nation. It had the largest slave market. At the sa... |
why do kids hate naps while adults seem to love them? | Kids are more interested in playing/learning than they are in resting. It it was the other way around they'd rest all the time and never learn anything | [
"Children are afraid to sleep on their own, to be on their own, even to go to the toilet alone. They feel that their parents cannot protect them. Bed wetting is a common manifestation of their anxiety and insecurity. Their parents are similarly anxious and frustrated. It is even difficult to speak of PTSD, for as l... |
what exactly is happening when you "pinch a nerve?" | It's exactly what its name suggests. A pinched nerve happens when a nerve is compressed too much by the surrounding tissue. This can be done by something external, like something else physically pinching you. But it can also happen internally, with tissue around a nerve swelling or constricting. The pressure pinches th... | [
"A pinched nerve occurs when pressure is placed on a nerve, usually from swelling due to an injury, or pregnancy and can result in pain, weakness, numbness or paralysis, an example being carpal tunnel syndrome. Symptoms can be felt in areas far from the actual site of damage, a phenomenon called referred pain. Refe... |
Why does Bhutan have a stronger relation to India than China? | Sorry this is late, but I might as well offer my 2Cents.
Geography, as has been mentioned earlier, is a big factor here. Bhutan is on the southern slope of the Himalayas. Indeed, it's actually shorter from Lhasa to Calcutta than to major Chinese cities, so even Tibet proper had a historically bigger trade network wit... | [
"Bhutan, situated between India and China, is a potential Sino-Indian battleground; India currently has more political influence in the nation. This stems from two things: the fact that after the British granted sovereignty to their South Asian possessions, Bhutan, a protectorate, was never put under the administra... |
Has a sitting world leader ever committed suicide in peace-time? What happened and what was the reaction? | [Getúlio Vargas](_URL_0_), President of Brazil at the time, committed suicide. It wasn't exactly a Führerbunker situation, but things weren't (as should be relatively unsurprising in postwar Latin America) exactly politically settled at that moment--generals were stirring up and demanding resignations.
As the Wikiped... | [
"Disillusioned with his own poverty and lack of support and recognition from the government, he committed suicide on 13 May 1966, by jumping into the well near his house in Model House Block-A colony, Jalandhar.\n",
"In 1909, Rio Branco was encouraged to run for the Presidency, but he declined, as he could not en... |
Is there any visible change or a shockwave in a star that transitions between fusing heavier elements? | It is a smooth transition and is shown in the evolution of most main sequence stars. Since energy from the center of a star can take thousands if not millions of years to reach the surface and the distribution of fused materials is pretty heterogeneous, the change would not be immediately apparent.
The only noticeabl... | [
"Nuclear fusion reactions that produce elements heavier than iron absorb nuclear energy and are said to be endothermic reactions. When such reactions dominate, the internal temperature that supports the star's outer layers drops. Because the outer envelope is no longer sufficiently supported by the radiation pressu... |
Do infants who are born deaf vocalize at birth? | Yes, deaf babies [babble](_URL_1_) (i.e. they make incohrent "ba ba" sounds), similar to hearing children. Of course since they cannot actually hear what they are saying, this form of babbling doesn't play the same key role in language acquisition as for hearing children. Interestingly, babies exposed to sign language ... | [
"A prelingual deaf individual is someone who was born with a hearing loss, or whose hearing loss occurred before they began to speak. Infants usually start saying their first words around one year. Therefore a prelingually deaf typically was either born deaf or lost their hearing before the age of one (the age when... |
why modern games lack loading bars? | Because they try to be creative, like instead of a loading bar they put a ship flying into wherever you go or they just put the emblem and animate it. | [
"While loading screens remain commonplace in video games, background loading is now used in many games, especially open world titles, to eliminate loading screens while traversing normally through the game, making them appear only when using warps or fast travel.\n",
"Namco has used playable mini-games during a l... |
what are the benefits of distributed computing compared to a single large supercomputer, and vice-versa? | Most distributed computing projects rely on people donating their computer time to working on your problem. This means that, outside of the software development & a little bit of server space to run the system, all your computing power is "free". It also serves to drum up good publicity for the work you're doing. ... | [
"BULLET::::2. There are many cases in which the use of a single computer would be possible in principle, but the use of a distributed system is \"beneficial\" for practical reasons. For example, it may be more cost-efficient to obtain the desired level of performance by using a cluster of several low-end computers,... |
Why did Napolean continue to use column formations in battle when experiences in the Peninsula war showed that line formations were more effective? | At Waterloo the main French attacks advanced in column, but wanted to deploy into a line for their actual attack. They knew how deadly the British 2 rank platoon fire could be(though at Waterloo the British were often in 4 ranks for fear of cavalry). Both Ney and D'Erlon had fought the British in Spain.
The first at... | [
"The line, column and square formations were the most recognised tactical formations in use during the Napoleonic era. Each of these formations had its own unique purpose in attacking or counter-attacking and no doubt played a large role in battlefield tactics. The line formation was the most favoured amongst the B... |
how the north and south poles can switch polarity periodically, and its implications. | The problem is that we don't know exactly how it works, for two main reasons:
1. We don't have direct observation of Earth's interior, what with it being deep underground.
2. Earth has not undergone a geomagnetic reversal during the very short time span that humans have been able to detect magnetism (about 2000 years... | [
"In the polar regions, directions can become complicated, with all geographic north–south lines converging at the poles. The difference between UPS grid north and true north can therefore be anything up to 180°—in some places, grid north is true south, and vice versa. UPS grid north is arbitrarily defined as being ... |
If I shot a gun from the edge of the atmosphere towards the earth, would the bullet increase in speed as it travels or slow down to a 'terminal velocity'? | I guess it depends where you define ['edge of the atmosphere.'](_URL_0_) You're basically in vacuum once you're above the mesopause.
If you start in the thermosphere or higher- let's just say we're shooting from the ISS - then your bullet will most likely increase in speed as it accelerates due to gravity as there is... | [
"The QTU Lapua external ballistics software, using continuous doppler drag coefficient (C) data provided by Lapua, predicts that such shots traveling would likely have struck their targets after nearly 6.0 seconds of flight time, having lost 93% of their kinetic energy, retaining of their original velocity, and hav... |
At what rate does water freeze? As in, when the portion of water reaches freezing temperature, does it freeze in an instant in its entirety, or does it start a discrete point and progress through the entire portion of water? If so, at what speed? | People have already posted about supercooling water below freezing.
I'll just point out that in normal freezing, when ice is formed the latent heat is released into the surrounding water, so the remaining water is raised to above freezing point.
Therefore the water can only freeze as fast as quickly as the heat can ... | [
"Water will freeze at different temperatures depending upon the type of ice nuclei present. Ice nuclei cause water to freeze at higher temperatures than it would spontaneously. For pure water to freeze spontaneously, called homogeneous nucleation, cloud temperatures would have to be . Here are some examples of ice ... |
Has it been empirically proven that tossing a coin gives both heads and tails equal probabilities? | There is, apparently, a bias towards landing on the side that was face-up at the beginning of the flip resulting in a ~51/49 split.
See [This Paper](_URL_0_). | [
"While a run of five heads has a probability of = 0.03125 (a little over 3%), the misunderstanding lies in not realizing that this is the case only before the first coin is tossed. After the first four tosses, the results are no longer unknown, so their probabilities are at that point equal to 1 (100%). The reasoni... |
how come there aren't vitamins named after every letter in the alphabet? and why did they name vitamins after letters anyway? | This [video](_URL_0_) explains it very well. It comes down to being historic, the people who discovered the vitamin named it, but some vitamins were actually two substances and some were the same substance with two names. This lead to this confusing system of vitamin names. | [
"The term \"vitamin\" is derived from the word \"vitamine\", coined in 1912 by Polish biochemist Casimir Funk, who isolated a complex of micronutrients essential to life, all of which he presumed to be amines. When this presumption was later determined not to be true, the \"e\" was dropped from the name. All vitami... |
Were there any examples of armor being "proofed" by spears, arrows, ect. before the invention of gunpowder weapons? | In Japan in the 14th century, individuals scales of armor were sometimes tested by firing arrows before being assembled. | [
"The proofing of armour is testing armour for its defensive ability, most commonly the historical testing of plate armour and mail (armour). In the early Middle Ages, armour would be classified by the blows it could withstand, being certified as proof against swords, axes, and arrows. As firearms emerged as battlef... |
what is the process that enables our eyeballs to move in synchronisation? | It's a neural connection. In ophthalmology there are two rules: Hering's law and Sherrington's law. Basically together these two laws describe the way the eyes can work together.
Whenever your brain tells you to look right, for example, it sends a signal to both eyes to tell them to turn right. It sends the same stren... | [
"The optokinetic response is a combination of a slow-phase and fast-phase eye movements. It is seen when an individual follows a moving object with their eyes, which then moves out of the field of vision at which point their eye moves back to the position it was in when it first saw the object. The reflex develops ... |
how do i tell if my computer has a powerful enough graphics card to run certain games? | The best way to tell if you can run a game is to use the web site _URL_0_
This web site will analyze your computer to figure out if you can run a particular game (you can just select the game from the search box). Keep in mind that you will need to authorize the website to access your computer so that it can scan your ... | [
"Once a hardware profile has been created the player must create a software profile. The player need not have any skill in programming, however, as the game requires no programming in the traditional sense. Instead the player is given a board, which varies in size depending on the CPU selected during the hardware d... |
what exactly are your rights when a cop wants to search you. | From the [ACLU](_URL_1_)
We rely on the police to keep us safe and treat us all fairly, regardless of race, ethnicity, national origin or religion. This card provides tips for interacting with police and understanding your rights.
Note: Some state laws may vary. Separate rules apply at checkpoints and when enterin... | [
"Police officers in various jurisdictions have power to search members of the public, for example, for weapons, drugs and stolen property. This article concerns searches of members of the public who have not been arrested and who are not held in detention. For search powers in relation to those persons see Search o... |
why does your body have trouble swallowing food that hasn't been chewed even when it's small enough to swallow whole? | Saliva moistens food as well as breaking it down. Easier for the body to handle if you already chewed it. | [
"The weakness of the muscles involved in swallowing may lead to swallowing difficulty (dysphagia). Typically, this means that some food may be left in the mouth after an attempt to swallow, or food and liquids may regurgitate into the nose rather than go down the throat (velopharyngeal insufficiency). Weakness of t... |
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