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Do electrons really 'relolve' around the nucleus?
|
> If an electron exists as an electron cloud, how can it 'revolve' around the nucleus?
You've just realized one of the gaping holes in the Bohr model.
> Or do they not revolve at all?
Not really. They just have certain probability distributions that describe where they're most likely to be.
> If so, why do we say that they have some angular momentum?
Because they have certain numbers that act like normal angular momentum mathematically.
|
[
"A direct relativistic effect is that as the atomic numbers of elements increase, the innermost electrons begin to revolve faster around the nucleus as a result of an increase of electromagnetic attraction between an electron and a nucleus. Similar effects have been found for the outermost s orbitals (and p ones, though in dubnium they are not occupied): for example, the 7s orbital contracts by 25% in size and is stabilized by 2.6 eV.\n",
"BULLET::::1. The electron is able to revolve in certain stable orbits around the nucleus without radiating any energy contrary to what classical electromagnetism suggests. These stable orbits are called stationary orbits and are attained at certain discrete distances from the nucleus. The electron cannot have any other orbit in between the discrete ones.\n",
"At any given instant, the electron will naturally be pushed towards the lower-voltage side of the tube. The electron will then oscillate back and forth as the voltage changes. At the same time, a strong magnetic field is applied, stronger than the critical value in the original design. This would normally cause the electron to circle back to the cathode, but due to the oscillating electrical field, the electron instead follows a looping path that continues toward the anodes.\n",
"In the decay, an electron and an antineutrino are ejected at great speed from the tritium nucleus, changing one of the neutrons into a proton with the release of 18,600 electronvolts (eV) of energy. The neutrino escapes the system; the electron is generally captured within a short distance, but far enough away from the site of the decay that it can be considered lost from the molecule. Those two particles carry away most of the released energy, but their departure causes the nucleus to recoil, with about 1.6 eV of energy. This recoil energy is larger than the bond strength of the carbon–helium bond (about 1 eV), so this bond breaks. The helium atom almost always leaves as a neutral , leaving behind the carbocation .\n",
"Half an optical cycle after ionization, the electron will reverse direction as the electric field changes, and will accelerate back towards the parent nucleus. Upon returning to the parent nucleus it can then emit bremsstrahlung-like radiation during a recombination process with the atom as it returns to its ground state. This description has become known as the recollisional model of high harmonic generation\n",
"While all these considerations did not \"prove\" an electron could not exist in the nucleus, they were challenging for physicists to interpret. In his 1931 textbook, Gamow summarized all these contradictions. Adding to the confusion in interpretation, the continuous energy distribution of beta decay electrons seemed to indicate that energy was not conserved by this \"nuclear electrons\" process. Indeed, Bohr, Gamow, Heisenberg and others considered the possibility that the laws of quantum mechanics were not applicable inside the nucleus. Such considerations were apparently reasonable, inasmuch as the laws of quantum mechanics had so recently overturned the laws of classical mechanics. The contradictions were mysterious and troublesome, until it was realized that there are no electrons in the nucleus.\n",
"Because the electron returns to the same point after the full trip around the equator, the phase of its wave function must be unchanged, which implies that the phase added to the wave function must be a multiple of :\n"
] |
How were hurricanes tracked in the 17th and 18th centuries?
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hurricanes were not 'tracked' in the 17th and 18th centuries. There was little understanding of cyclonic storms and no means of instantaneous communications. A track could be made well after the fact, but that was not 'tracking' in the sense we use the word today.
|
[
"The List of Atlantic hurricanes in the 17th century encompasses all known and suspected Atlantic tropical cyclones from 1600 to 1699. Although records of every storm that occurred do not survive, the information presented here originated in sufficiently populated coastal communities and ships at sea that survived the tempests.\n",
"The List of Atlantic hurricanes in the 18th century encompasses all known Atlantic tropical cyclones from 1700 to 1799. Although not all of the data for every storm that occurred are available, some parts of the coastline were populated enough to provide data of hurricane occurrences.\n",
"Prior to the advent of modern tropical cyclone tracking technology, notably satellite imagery, many hurricanes that did not affect land directly went unnoticed, and storms that did affect land were not recognized until their onslaught. As a result, information on older hurricane seasons was often incomplete. Modern-day efforts have been made and are still ongoing to reconstruct the tracks of known hurricanes and to identify initially undetected storms. In many cases, the only evidence that a hurricane existed was reports from ships in its path. Judging by the direction of winds experienced by ships, and their location in relation to the storm, it is possible to roughly pinpoint the storm's center of circulation for a given point in time. This is the manner in which three of the eight known storms in the 1861 season were identified by hurricane expert José Fernández Partagás's reanalysis of hurricane seasons between 1851 and 1910. Partagás also extended the known tracks of most of the other tropical cyclones previously identified by scholars. The information Partagás and his colleague uncovered was largely adopted by the National Oceanic and Atmospheric Administration's Atlantic hurricane reanalysis in their updates to the Atlantic hurricane database (HURDAT), with some slight adjustments. HURDAT is the official source for such hurricane data as track and intensity, although due to a sparsity of available records at the time the storms existed, listings on some storms are incomplete.\n",
"Hurricane Gladys was the first Atlantic hurricane to be observed each by the Hurricane Hunters, radar imagery, and photographs from space. The seventh named storm and fifth hurricane (including one unnamed hurricane) of the 1968 season, Gladys formed on October 13 in the western Caribbean from a broad disturbance related to a tropical wave. The storm moved north-northwestward, becoming a hurricane before striking Cuba on October 16. Gladys later reached peak winds of 85 mph (140 km/h) just before making landfall near Homosassa on the western coast of Florida on October 19. The hurricane crossed the state and continued northeastward, passing just east of Cape Hatteras on October 20. The next day, Gladys became extratropical and was absorbed by a cold front over Nova Scotia.\n",
"Prior to the advent of modern tropical cyclone tracking technology, notably satellite imagery, many hurricanes that did not affect land directly went unnoticed, and storms that did affect land were not recognized until they made landfall. As a result, information on older hurricane seasons was often incomplete. Modern-day efforts have been made and are still ongoing to reconstruct the tracks of known hurricanes and to identify initially undetected storms. In many cases, the only evidence that a hurricane existed was reports from ships in its path. However, judging by the direction of winds experienced by ships, and their location in relation to the storm, it is possible to roughly pinpoint the storm's center of circulation for a given point in time. This is the manner in which four of the seven known storms in the 1860 season were identified by hurricane expert José Fernández Partagás's reanalysis of hurricane seasons between 1851 and 1910. Partagás also extended the known tracks of three other hurricanes previously identified by scholars. The information Partagás and his colleague uncovered was largely adopted by the National Oceanic and Atmospheric Administration's Atlantic hurricane reanalysis in their updates to the Atlantic hurricane database (HURDAT), with some slight adjustments. HURDAT is the official source for such hurricane data as track and intensity, although due to a sparsity of available records at the time the storms existed, listings on some storms are incomplete.\n",
"The 1870 Atlantic hurricane season lasted from mid-summer to late-fall and comprised one tropical storm and ten hurricanes, two of which became major hurricanes, (Category 3+). However, in the absence of modern satellite and other remote-sensing technologies, only storms that affected populated land areas or encountered ships at sea were recorded, so the actual total could be higher. An undercount bias of zero to six tropical cyclones per year between 1851 and 1885 and zero to four per year between 1886 and 1910 has been estimated.\n",
"Prior to the advent of modern tropical cyclone tracking technology, notably satellite imagery, many hurricanes that did not affect land directly went unnoticed, and storms that did affect land were not recognized until their onslaught. As a result, information on older hurricane seasons was often incomplete. Modern-day efforts have been made and are still ongoing to reconstruct the tracks of known hurricanes and to identify initially undetected storms. In many cases, the only evidence that a hurricane existed was reports from ships in its path, and judging by the direction of winds experienced by ships, and their location in relation to the storm, it is possible to roughly pinpoint the storm's center of circulation for a given point in time. This is the manner in which all of the five known storms in the 1907 season were identified by hurricane expert José Fernández-Partagás's reanalysis of hurricane seasons between 1851 and 1910. Partagás also extended the known tracks of three other hurricanes previously identified by scholars. The information Partagás and his colleague uncovered was largely adopted by the National Oceanic and Atmospheric Administration's Atlantic hurricane reanalysis in their updates to the Atlantic hurricane database (HURDAT), with some slight adjustments. HURDAT is the official source for such hurricane data as track and intensity, although due to a sparsity of available records at the time the storms existed, listings on some storms are incomplete.\n"
] |
The question that my professors/teachers have never been able to answer. What's the lowest temperature a flame can have.
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You question is nearly impossible to answer because there really isn't a good formal definition of a flame or fire. It's more of an, "I know it when I see it" thing. There are plenty of chemical reactions that give off both heat and light that can occur at low temperatures.
If you managed to get a photoluminescent molecule like luminol into the gas phase and catalyzed it's oxidative decomposition, it would make something that you would probably call a flame, but it wouldn't be hot at all.
|
[
"Note these are theoretical, not actual, flame temperatures produced by a flame that loses no heat. The closest will be the hottest part of a flame, where the combustion reaction is most efficient. This also assumes complete combustion (e.g. perfectly balanced, non-smokey, usually bluish flame)\n",
"In the study of combustion, there are two types of adiabatic flame temperature depending on how the process is completed: the \"constant volume\" and \"constant pressure;\" both of which describe temperature that combustion products theoretically can reach if no energy is lost to the outside environment.\n",
"An air-only torch will burn at around 1,995 °C (3,623 °F), less if heat loss to the surroundings is taken into account. Even glass bead-making torches, which are essentially Bunsen burners with an added air pump, can only achieve actual operating temperatures of . Oxygen-fed torches can be much hotter at up to 2,820 °C (5,110 °F), depending on the fuel-oxygen ratio, and whether MAPP or propane gas is used. Actual flame temperatures are generally lower due to incomplete combustion and heat loss to the surroundings.\n",
"Cool flame can occur in hydrocarbons, alcohols, aldehydes, oils, acids, waxes, and even methane. The lowest temperature of a cool flame is poorly defined and is conventionally set as temperature at which the flame can be detected by eye in a dark room (cool flames are hardly visible in daylight). This temperature slightly depends on the fuel to oxygen ratio and strongly depends on gas pressure – there is a threshold below which cool flame is not formed. A specific example is 50% n-butane–50% oxygen (in volume percent) which has a cool flame temperature (CFT) of about 300 °C at . One of the lowest CFTs (156 °C) was reported for a CHOCH + O + N mixture at . The CFT is significantly lower than the auto-ignition temperature (AIT) of conventional flame (see table).\n",
"where formula_7 is the activation barrier for the burning reaction and formula_8 is the temperature developed as the result of burning; the value of this so-called \"flame temperature\" can be determined from the laws of thermodynamics.\n",
"By way of example, the adiabatic flame temperature is an idealization that uses the \"adiabatic approximation\" so as to provide an upper limit calculation of temperatures produced by combustion of a fuel. The adiabatic flame temperature is the temperature that would be achieved by a flame if the process of combustion took place in the absence of heat loss to the surroundings.\n",
"A cool flame is a flame having maximal temperature below about . It is usually produced in a chemical reaction of a certain fuel-air mixture. Contrary to conventional flame, the reaction is not vigorous and releases very little heat, light, and carbon dioxide. Cold fires are difficult to observe and are uncommon in everyday life, but they are responsible for engine knock – the undesirable, erratic, and noisy combustion of low-octane fuels in internal combustion engines.\n"
] |
what happens after you burst a blood vessel? does the vessel itself reform or do you have a gap there forever?
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It's called a bruise. The blood leaks out under your skin and makes a spill. The body patches up the vessel, or seals it off if it's too damaged. Then it cleans up the mess, that's why the bruise turns colors as the crashed blood cells get cleaned up, like after a highway crash. Then you are fine. Other nearby vessels expand and/or new ones grow to ge4t the traffic flow back to normal.
|
[
"Blood vessel permeability is increased in inflammation. Damage, due to trauma or spontaneously, may lead to hemorrhage due to mechanical damage to the vessel endothelium. In contrast, occlusion of the blood vessel by atherosclerotic plaque, by an embolised blood clot or a foreign body leads to downstream ischemia (insufficient blood supply) and possibly necrosis. Vessel occlusion tends to be a positive feedback system; an occluded vessel creates eddies in the normally laminar flow or plug flow blood currents. These eddies create abnormal fluid velocity gradients which push blood elements such as cholesterol or chylomicron bodies to the endothelium. These deposit onto the arterial walls which are already partially occluded and build upon the blockage.\n",
"partial vessel collapse occurs in vessels which undergo conditions of higher external pressure relative to the fluid within and can be difficult to predict mathematically. As such, devices such as a Starling Resistor are often used to predict fluid flow under these conditions.\n",
"As long as this process is gradual, the tissue gas loading in the diver will reduce by diffusion and perfusion until it eventually re-stabilises at the current saturation pressure. The problem arises when the pressure is reduced more quickly than the gas can be removed by this mechanism, and the level of supersaturation rises sufficiently to become unstable. At this point, bubbles may form and grow in the tissues, and may cause damage either by distending the tissue locally, or blocking small blood vessels, shutting off blood supply to the downstream side, and resulting in hypoxia of those tissues.\n",
"Another large component of the remodelling process is the disconnection of branched vessels, which then migrate to distal areas in order to supply blood homogeneously. Branching morphogenesis has been found to follow the dielectric breakdown model, in that only the vessels with sufficient flow will enlarge, while others will close off. At locations inside the vessel where two tube split off from one, one arm of the split is likely to close, detach, and migrate towards the venous line, where it will re-attach. The result of the closure of a branch is that flow increases and becomes less turbulent in the main line, while blood also begins to flow towards areas which are lacking. Which branch will close depends on the flow rate, direction, and branching angle; in general, a branching angle of 75° or more will necessitate the closing of the smaller branch.\n",
"Immediately after a blood vessel is breached, ruptured cell membranes release inflammatory factors like thromboxanes and prostaglandins that cause the vessel to spasm to prevent blood loss and to collect inflammatory cells and factors in the area. This vasoconstriction lasts five to ten minutes and is followed by vasodilation, a widening of blood vessels, which peaks at about 20 minutes post-wounding. Vasodilation is the end result of factors released by platelets and other cells. The main factor involved in causing vasodilation is histamine. Histamine also causes blood vessels to become porous, allowing the tissue to become edematous because proteins from the bloodstream leak into the extravascular space, which increases its osmolar load and draws water into the area. Increased porosity of blood vessels also facilitates the entry of inflammatory cells like leukocytes into the wound site from the bloodstream.\n",
"A thrombus occurs when the hemostatic process, which normally occurs in response to injury, becomes activated in an uninjured or slightly injured vessel. A thrombus in a large blood vessel will decrease blood flow through that vessel (termed a mural thrombus). In a small blood vessel, blood flow may be completely cut off (termed an occlusive thrombus), resulting in death of tissue supplied by that vessel. If a thrombus dislodges and becomes free-floating, it is considered an embolus.\n",
"Die swell is a phenomenon directly related to entropy and the relaxation of the polymer within the flow stream. Initially, a flow stream has a constant rate before entering the die, and the polymers within the stream occupy a roughly spherical conformation, maximizing entropy. Extrusion through the die causes an increase in flow rate through the polymer flow stream. As the polymer spends time inside the die and is subject to the much increased flow rate, the polymers lose the spherical shape, becoming longer due to the increased flow rate. Physical entanglements may relax, if the time scale of the polymer within the die is long enough. When the polymer stream leaves the die, the remaining physical entanglements cause the polymers in the die stream to regain a portion of its former shape and spherical volume, in order to return to the roughly spherical conformation that maximizes entropy.\n"
] |
Do any non-human animals "remember" things in a way like humans, or only through conditioning? Can an animal "remember" another animal that harmed it? Can an animal plot revenge?
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Crows remember shit for years. [here](_URL_0_)
Another example is a silverback that, through sign language, described his mother being killed by poachers. He was full grown. [here](_URL_1_)
...now if only my dachshund would remember us saving her when she was a pup next time she has the urge to leave us a "treat" on the floor...
|
[
"A study published in 2014 by neuroscientists based at the University of Minnesota suggested that rats are capable of feeling regret about their actions. This emotion had never previously been found in any other mammals apart from humans. Researchers set up situations to induce regret, and rats expressed regret through both their behavior and specific neural patterns in brain activity.\n",
"Many criticisms surrounding episodic-like memory in animals revolve around the Bischof-Kohler Hypothesis. The Bischof-Kohler hypothesis holds that only humans can dissociate themselves from their current motivation and take action for future needs. It suggests that animals are incapable of anticipating future needs, and any future-oriented behaviours they exhibit are either fixed action patterns or cued by their current motivational state.\n",
"The study of memory has greatly benefited from experimentation with animals. Current ethical guidelines state that using animals for scientific purposes is only acceptable when the harm (physical or psychological) done to animals is outweighed by the benefits of the research. Keeping this in mind, we can use research techniques on animals that would not necessarily be performed on humans.\n",
"After a study done by the University of Edinburgh (2006), hummingbirds were the first animal to demonstrate two of the aspects of episodic memory—the ability to recall where certain flowers were located and how recently they were visited. Other studies have demonstrated this type of memory in different animal species, such as dogs, rats, honey bees, and primates.\n",
"Psychologists who work with animals assume that the things they learn can be applied to the human brain. Memory is a complex system that relies on interactions between many distinct parts of the brain. In order to fully understand memory, researchers must cumulate evidence from human, animal, and developmental research in order to make broad theories about how memory works. Intraspecies comparisons are key. Rats for example display extremely complex behaviours and most of the structures in their brain parallel those in humans. Due to their relatively simple organization, slugs can be useful for studying how neurons interconnect to produce observable behaviour. Fruit flies are useful for studying gene-behaviour interactions because many generations with genetic alterations can be quickly bred in the laboratory.\n",
"An alternate theory was posited in the 1960s, when scientists conducted experiments in a search for molecules responsible for memory. In one experiment, rats, normally nocturnal animals, were conditioned to fear the dark and a substance called \"scotophobin\" was supposedly extracted from the rats' brains; this substance was claimed to be responsible for remembering this fear. These findings were subsequently debunked.\n",
"Adaptive memory behaviours have been observed in animal species, as well as humans. Dr. John Garcia discovered that taste aversion conditioning in rats results in a lasting association between sickness and an ingested substance, and that aversion can be established after only one trial. This rapid learning led others to the idea that rats have biological dispositions for learning to associate sickness with a taste memory as a result of its evolutionary history. The results of a study that compared rats and quail in the acquisition of taste aversion suggested that rats rely on their memory of taste to avoid nausea while quail relied on their visual memory. Since the rat is a nocturnal feeder and has poor vision, it was suggested that they rely on taste cues to learn to avoid toxic substances, leading to a highly developed chemical sense system.\n"
] |
How much radiation does a single banana give off? How many bananas would it take to kill someone and how long would that process take?
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You basically couldn't kill someone by just piling bananas around them. The amount of radiation you need to get someone to kick the bucket is on the order of 2-5 Gy (joules per kg). Even using natural K metal (with a small % of K40), being surrounded by an infinite sphere wouldn't even come near a harmful dose. You'd need to separate out the K-40, then pile it around/in someone. I suspect you'd need on the order of a couple of Ci (1Ci = 3.7E10 Bq) to cause harm, which would require you refine ~10^6 - 10^7 kg of natural potassium. TL;DR: Ain't happening
|
[
"The radiation exposure from consuming a banana is approximately 1% of the average daily exposure to radiation, which is 100 banana equivalent doses (BED). The maximum permitted radiation leakage for a nuclear power plant is equivalent to 2,500 BED (250 μSv) per year, while a chest CT scan delivers 70,000 BED (7 mSv). A lethal dose of radiation is approximately 35,000,000 BED (3500 mSv). A person living from the Three Mile Island nuclear reactor received an average of 800 BED of exposure to radiation during the 1979 Three Mile Island accident.\n",
"The radiation exposure from consuming one banana is approximately 1% of the average daily exposure to radiation, or about 50 times less than a typical x-ray in a dental exam and 400 times less than taking a commercial flight across the United States.\n",
"It follows that the \"additional\" radiation exposure due to eating a banana lasts only for a few hours after ingestion, i.e. the time it takes for the normal potassium content of the body to be restored by the kidneys. The EPA conversion factor, on the other hand, is based on the mean time needed for the isotopic mix of potassium isotopes in the body to return to the natural ratio after being disturbed by the ingestion of pure K, which was assumed by EPA to be 30 days. If the assumed time of residence in the body is reduced by a factor of ten, for example, the estimated equivalent absorbed dose due to the banana will be reduced in the same proportion.\n",
"Bananas, like most organic material, naturally contain a certain amount of radioactive isotopes—even in the absence of any artificial pollution or contamination. The banana equivalent dose, defined as the additional dose a person will absorb from eating one banana, expresses the severity of exposure to radiation, such as resulting from nuclear weapons or medical procedures, in terms that would make sense to most people. This is approximately 78 nanosieverts - in informal publications one often sees this estimate rounded up to 0.1 μSv.\n",
"The dose uptake from ingested material is defined as committed dose, and in the case of the overall effect on the human body of the radioactive content of a banana, it will be the \"committed effective dose\". This is typically given as the net dose over a period of 50 years resulting from the intake of radioactive material.\n",
"According to the US Environmental Protection Agency (EPA), isotopically pure potassium-40 will give a committed dose equivalent of 5.02 nSv over 50 years per becquerel ingested by an average adult. Using this factor, one banana equivalent dose comes out as about 5.02 nSv/Bq × 31 Bq/g × 0.5 g ≈ 78 nSv = 0.078 μSv. In informal publications, one often sees this estimate rounded up to 0.1 μSv. The International Commission on Radiological Protection estimates a coefficient of 6.2 nSv/Bq for the ingestion of potassium-40, with this datum the calculated BED would be 0.096 μSv, closer to the standard value of 0.1 μSv.\n",
"The origins of the concept are uncertain, but one early mention can be found on the RadSafe nuclear safety mailing list in 1995, where Gary Mansfield of the Lawrence Livermore National Laboratory mentions that he has found the \"banana equivalent dose\" to be \"very useful in attempting to explain infinitesimal doses (and corresponding infinitesimal risks) to members of the public\". A value of 9.82×10 sieverts or about was suggested for a banana.\n"
] |
how is youtube a sustainable business model? if view count remains constant but video storage costs continue to increase, wouldn't this lead to a permanent loss?
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Storage costs are going down exponentially.
Every year the cost of storing 1 GB of data is half what it was the previous year.
YouTube loses money every time someone uploads a long video that nobody watches, but it doesn't matter because they make insanely high profits off of the top 1% of the most popular videos.
As long as YouTube is a good place for popular videos, the business model is sustainable.
If it turned into an unpopular site where people just uploaded their personal videos but nothing popular or viral ever went there, it'd lose money.
|
[
"In June 2009, \"BusinessWeek\" reported that, according to San Francisco-based IT consulting company RampRate, YouTube was far closer to profitability than previous reports, including the April 2009, projection by investment bank Credit Suisse estimating YouTube would lose as much as $470 million in 2009. RampRate's report pegged that number at no more than $174 million.\n",
"On January 22, 2018, the limit for Basic accounts was changed for the first time in 11 years. Accounts were limited to a lifetime video storage limit of 5 GB. Those which exceeded this limit prior to its implementation can keep uploaded videos online, but cannot upload new videos. The storage limit was implemented just two days after YouTube announced the demonetization of smaller channels, those with fewer than 1,000 lifetime subscribers and 4,000 annual hours of watch time, though Vimeo has yet to confirm that this directly caused the new limit.\n",
"The second view is e.g. taken by Christian Fuchs in his book \"Internet and Society\". He argues that YouTube is an example of a business model that is based on combining the gift with the commodity. The first is free, the second yields profit. The novel aspect of this business strategy is that it combines what seems at first to be different, the gift and the commodity. YouTube would give free access to its users, the more users, the more profit it can potentially make because it can in principle increase advertisement rates and will gain further interest of advertisers. YouTube would sell its audience that it gains by free access to its advertising customers.\n",
"Google did not provide detailed figures for YouTube's running costs, and YouTube's revenues in 2007 were noted as \"not material\" in a regulatory filing. In June 2008, a \"Forbes\" magazine article projected the 2008 revenue at $200 million, noting progress in advertising sales.\n",
"Although there are many websites that allow the upload of photographs and videos, digital preservation for the long-term is still an issue. There is a lack of confidence that such websites are capable of storing data for long periods of time (ex. 50 years) without data degradation or loss.\n",
"Google does not provide detailed figures for YouTube's running costs, and YouTube's revenues in 2007 were noted as \"not material\" in a regulatory filing. In June 2008, a \"Forbes\" magazine article projected the 2008 revenue at $200 million, noting progress in advertising sales. In January 2012, it was estimated that visitors to YouTube spent an average of 15 minutes a day on the site, in contrast to the four or five hours a day spent by a typical US citizen watching television. In 2012, YouTube's revenue from its ads program was estimated at $3.7 billion. In 2013 it nearly doubled and estimated to hit $5.6 billion according to eMarketer, while others estimated $4.7 billion. The vast majority of videos on YouTube are free to view and supported by advertising. In May 2013, YouTube introduced a trial scheme of 53 subscription channels with prices ranging from $0.99 to $6.99 a month. The move was seen as an attempt to compete with other providers of online subscription services such as Netflix and Hulu. In 2017, viewers on average watch YouTube on mobile devices for more than an hour every day.\n",
"To reduce the data rate without significantly reducing quality, the size of the GOP can be increased, the maximum data rate can be exceeded, and a different MPEG-2 quantization matrix can be used. These changes can be advantageous for those who want to either maximize video quality, or use fewer discs.\n"
] |
does *absolutely everyone* on the sidelines of an nfl game have a reason to be there?
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No. Some people including some family members and celebrities are occasionally allowed on the sidelines. Most of the people there are necessary though.
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[
"Residents choose teams around the country to support; David Carter, sports business professor at USC, compared area fans to \"the NFL's version of the United Nations\". Many are from elsewhere in the United States and tend to support teams from their previous cities. 10% of Los Angeles County residents who followed NFL Tweets followed the 49ers, 9% the Raiders, and 7% the Dallas Cowboys. In Orange County, the Chargers and Green Bay Packers were in second and third place. By contrast, in San Diego County 47% of NFL Twitter users followed the Chargers and no other team had more than 4.5%, despite the area having many loyal NFL fans of other teams (notably the Pittsburgh Steelers) due to the numerous military bases in the area.\n",
"The December 18, 1938, \"Dallas Morning News\" said \"Whether they play now on a team, used to play back in the day, follow the game closely or just quarterback from the grandstand occasionally, every American football enthusiast well knows how much that twelfth man in the stands means to any American football team. But that backing means unusually much in the traditional Thanksgiving game between the University of Texas and Texas A&M. With an uncertain monotony that has long since made game forecasters exceedingly skittish, these two win where their twelfth men help most.\" Thus, in this single instance, the term \"Twelfth Man\" was used to refer to the fans of both schools playing.\n",
"During home games, the attendance is announced to the crowd, along with the number of no-shows (the fans subsequently boo the no-shows). The fans are also known to chant \"IN-COM-PLETE!\" every time the visiting team throws an incomplete pass. The stadium's legendary home-field advantage is regarded as one of the best in the NFL, especially during the playoffs. The Broncos had the best home record in pro football over a 32-year span from 1974 to 2006 (191–65–1). Mile High Stadium was one of the NFL's loudest stadiums, with steel flooring instead of concrete, which may have given the Broncos an advantage over opponents, plus the advantage of altitude conditioning for the Broncos. In , the team moved into Invesco Field at Mile High, built next to the former site of the since-demolished Mile High Stadium. Sportswriter Woody Paige, along with many of Denver's fans, however, often refuse to call the new stadium by its full name, preferring to use \"Mile High Stadium\" because of its storied history and sentimental import. Additionally, \"The Denver Post\" had an official policy of referring to the stadium as simply \"Mile High Stadium\" in protest, but dropped this policy in 2004.\n",
"As with all sports leagues, there are a number of significant rivalries in the National Football League (NFL). Rivalries are occasionally created due to a particular event that causes bad blood between teams, players, coaches, or owners, but for the most part, they arise simply due to the frequency with which some teams play each other, and sometimes exist for geographic reasons.\n",
"Rivalries in the NFL are commonly recognized as such by fans and players alike. While many rivalries are well established, others are of more recent vintage, accepted as existing by the nature of the competition and history between the two teams. Other rivalries have fallen by the wayside due to league realignment and reduction in frequencies of meetings.\n",
"In the National Football League (NFL), there are few two-way players, as most offensive players do not play on defense and vice versa. A major concern is the possibility of injury when a player is \"overused.\"\n",
"In the National Football League backup players, particularly the quarterback, are seen on the sidelines carrying a clipboard. Football analysts often use the notion of \"carrying a clipboard\" as an object of derision indicating that said football player is not good enough to play on the field.\n"
] |
facebook scams. what do the accomplish by getting you to share a post?
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They are often designed to build up likes and followers then the owners of the page (usually located in a developing country not always though) will sell the page to scammers who can reach a giant audience (iPhone giveaways porn spam snake-oil weight loss solutions etc)
|
[
"Social networking sites have created issues among getting hired for jobs and losing jobs because of exposing inappropriate content, posting photos of embarrassing situations or posting comments that contain potentially offensive comments (e.g., racist, homophobic or defamatory comments), or even political comments that are contrary to those of the employer. There are works which recommend friends to social networking users based on their political opinions. Many people use social networking sites to express their personal opinions about current events and news issues to their friends. If a potential applicant expresses personal opinions on political issues or makes potentially embarrassing posts online on a publicly available social networking platform, employers can access their employees' and applicants' profiles, and judge them based on their social behavior or political views. According to \"Silicon Republic's\" statistics, 17,000 young people in six countries were interviewed in a survey. 1 in 10 people aged 16 to 34 have been rejected for a job because of comments made on an online profile. This shows the effects that social networks have had on people's lives. There have been numerous cases where employees have lost jobs because their opinions represented their companies negatively. In September 2013, a woman got fired over Facebook because she posted disruptive information about her company stating that military patrons should not receive special treatment or discounts. A manager of the company found her opinion online, disagreed with it, and fired her because it went against the company's mission statement. In November 2012, a woman posted a racist remark about the President of the United States and mentioned a possible assassination. She lost her job, and was put under investigation by the Secret Service.\n",
"There are several other risks that come with using social login tools. These logins are also a new frontier for fraud and account abuse as attackers use sophisticated means to hack these authentication mechanisms. This can result in an unwanted increase in fraudulent account creations, or worse; attackers successfully stealing social media account credentials from legitimate users. One such way that social media accounts are exploited is when users are enticed to download malicious browser extensions that request read and write permissions on all websites. These users are not aware that later on, typically a week or so after being installed, the extensions will then download some background Javascript malware from its command and control site to run on the user's browser. From then on, these malware infected browsers can effectively be controlled remotely. These extensions will then wait until the user logs into a social media or another online account, and using those tokens or credentials will sign up for other online accounts without the rightful user's express permission.\n",
"BULLET::::- Messages can be sent between Facebook participants through 'Facebook messages', which are not public, or 'wall postings', which can be viewed by anyone specified in the user's privacy controls. Posting messages which may be perceived as private, embarrassing, or inappropriate to a wall posting can create expectancy violations.\n",
"Facebook issued a statement stating: \"A like that doesn't come from someone truly interested in connecting with the brand benefits no one. If you run a Facebook page and someone offers you a boost in your fan count in return for money, our advice is to walk away – not least because it is against our rules and there is a good chance those likes will be deleted by our automatic systems. We investigate and monitor \"like-vendors\" and if we find that they are selling fake likes, or generating conversations from fake profiles, we will quickly block them from our platform.\" Andrea Faville reported that Alphabet Inc. companies, Google and YouTube, \"take action against bad actors that seek to game our systems.\" LinkedIn spokesman Doug Madey said buying connections \"dilutes the member experience violates their user agreement and can also prompt account closures.\" Chief executive and founder of Instagram, Kevin Systrom reports \"We've been deactivating spammy accounts from Instagram on an ongoing basis to improve your experience.\"\n",
"Facebook has also been a mode in which crowdsourcing can occur, as users typically ask a question in their status message hoping those that see it on his or her news feed will answer the question, or users may opt to use the poll option now available to obtain information from those within their friends network.\n",
"The group has been known to remove people from its Facebook group for challenging its message. It has removed members who disagreed with its leadership on certain issues and deleted messages that it found \"inappropriate.\" It also purged students from the group.\n",
"However, due to the privacy policy design, acquiring true information on Facebook is no trivial task. Often, Facebook users either refuse to disclose true information or set information only visible to friends, Facebook users who \"LIKE\" your page are also hard to be identified. To do online profiling of users and to cluster users, marketers and companies can and will access the following kinds of data: gender, the IP address and city of each user through the Facebook Insight page, who \"LIKED\" a certain user, a page list of all the pages that a person \"LIKED\" (transaction data), other people that a user follow (even if it exceeds the first 500, which we usually can not see)and all the publicly shared data.\n"
] |
how do web browsers work?
|
When you request _URL_0_, the server sends back a bunch of textual data. Plain text is boring to look at, so a simple markup language was created named html. The browsers job is to parse through the html and display it nicely. Some browsers display things differently than others (that's why many people hate internet explorer).
Requesting for a page can be very resource intensive on the browser (intensive in a very relative term). Most sites share similar layouts, so each request may be 95% of the same data (things like the header, footer). It doesn't make sense to request almost the same thing, so caching was invented. A browser stores commonly requested things locally on your computer. Caching improves the time for pages to load, since most of it is stored locally.
Offline browsing uses the cache to save complete pages. If all the content is saved onto your computer, then you don't need a connection to view it. Thus, offline viewing. Offline viewing is only practical for pages which have content that never changes. If the page depends on any user submission, then obviously it won't work.
A session is an exchange of information between the browser and the web application. They use 'cookies' to keep this information sorted. Cookies are nothing more than simple text files that your browser manages. Sessions and cookies are used alot in the internet, but for the average five year old, they keep you logged in for a specific time on a site. Cookies are the reason why you stay logged into Facebook on your computer. The cookie is stored only on your computer.
As for security, browsers don't do much. They can recognise certificates a site must have in order to be 'secure' (Called an SSL certificate). They can also recognize an invalid one too. They aren't smart enough to do much else though, that is left up to the user.
I hope this helps!
|
[
"A web browser is a software application for retrieving, presenting and traversing information resources on the World Wide Web. It further provides for the capture or input of information which may be returned to the presenting system, then stored or processed as necessary. The method of accessing a particular page or content is achieved by entering its address, known as a Uniform Resource Identifier or URI. This may be a web page, image, video, or other piece of content. Hyperlinks present in resources enable users easily to navigate their browsers to related resources.\n",
"A web browser (commonly referred to as a browser) is a software application for accessing information on the World Wide Web. Each individual web page, image, and video is identified by a distinct Uniform Resource Locator (URL), enabling browsers to retrieve these resources from a web server and display them on a user's device.\n",
"A \"web browser\" (commonly referred to as a \"browser\") is a software user agent for accessing information on the World Wide Web. To connect to a website's server and display its pages, a user needs to have a web browser program. This is the program that the user runs to download, format and display a web page on the user's computer.\n",
"Browser service or Computer Browser Service is a feature of Microsoft Windows to let users easily browse and locate shared resources in neighboring computers. This is done by aggregating the information in a single computer \"Browse Master\" (or \"Master Browser\"). All other computers contact this computer for information and display in the Network Neighborhood window.\n",
"A browser user interface (or BUI) is a method of interacting with an application, typically hosted on a remote device, via controls presented within a web browser. This is an alternative to providing controls via a separate application with a dedicated graphical user interface (GUI) or command-line interface (CLI).\n",
"By embedding a full-fledged web browser, such as the Internet Explorer or the Mozilla browser control, programs can retrieve the dynamic content generated by client-side scripts. These browser controls also parse web pages into a DOM tree, based on which programs can retrieve parts of the pages.\n",
"Internet Browser allows users to browse the web on the Wii U GamePad and/or the television screen. It functions as a multitasking application on the Wii U, so it can be used while another game or application is suspended in the background. The browser is primarily controlled using the Wii U GamePad's touchscreen, or with the analog stick to scroll through web pages and the D-pad to cycle through links on the page, similar to using a keyboard. It can play HTML 5 video and audio in websites such as YouTube and various other social media. The user can choose to hide the browser's view on the TV screen for privacy, which contains presentation effects such as the opening of stage curtains. The user can also choose between the Google and Yahoo! search engines. There is a text wrap option to automatically wrap text to the width of the screen at different zoom levels. Users can also create bookmarks, with each user having its own set of personal bookmarks. The browser supports up to six tabs simultaneously. Up to 32 pages can be stored into the browser's history before the older items start being replaced.\n"
] |
When the United States annexed the former territory of Mexico (California, Utah, Nevada, Arizona, New Mexico, Texas), why were the Spanish names of cities such as Los Angeles and San Francisco retained?
|
generally speaking, pre-existing towns or settlements weren't renamed, and san francisco is the exception. [according to the 1847 ordinance changing the name of the town,](_URL_0_) "yerba buena" was renamed "san francisco" to prevent confusion. [look, for instance, at this 1839 American map of the US and Mexico-- the settlement of yerba buena is mislabeled as "st. francisco,"](_URL_4_) but the other dots on the map of california generally correlate with their modern names. [see also this 1846 map,](_URL_1_) where most settlements (except for modern sacramento) have recognizable names-- and the settlement on san francisco bay is called "san francisco" by the cartographers rather than its proper name of "yerba buena."
there was no wholesale renaming. don't forget that a sizeable number of mexicans living in california flipped over to the american government during the mexican war. i'll turn it over to a previous post i made, detailing the chaotic conditions in mexico that led to californios going over to the american side:
[Copy-pasted from a previous reply](_URL_2_):
> [in addition to the internal warfare over control over the government, major portions of the country tried to secede.](_URL_3_) while the republic of the rio grande and the republic of yucatan never really got off the ground, texas managed to successfully beat back the mexican army and gained its independence in 1836.
> california was not excluded from this political turmoil, and several mexican governors ended up getting being violently removed-- california governors micheltorena, gutierrez and victoria were all deposed by violent revolt. mexico was doing so badly at the time that multiple former mexican governors of california actually were in favor of being annexed by foreign powers. the relative stability brought by the americans was welcomed by a significant portion of californio society, including mariano vallejo, the richest man in california. many of the rest, like former mexican governors andres pico and pio pico, ended up staying on after the switch to american control and remaining prominent citizens. (andres pico, for instance, was elected to the california legislature and served in the state militia after the americans took over.)
given this chaos, and the defection of large numbers of the californio elite, it's not surprising that the names stayed in place. i have a handy table of the spanish, english, and modern names of the places marked, too, from north to south.
Spanish name | English name (1846 map) | Modern city
---|---|----
Nueva Helvetia | New Helvetia | Overtaken by the adjacent City of Sacramento in the 1800s
Yerba Buena | San Francisco | San Francisco
Misión Santa Clara de Asís | Santa Clara | Santa Clara
Pueblo San José de Guadalupe | San Jose | San Jose
Monterey | Monterey | Monterey
Misión San Miguel Arcángel | San Miguel | San Miguel
Misión San Luis Obispo de Tolosa | San Luis Obispo | San Luis Obispo
Misión La Purísima Concepción | La Purissima | Lompoc (named after the local ranch rather than the mission)
Misión Santa Bárbara | Santa Barbara | Santa Barbara
Misión San Buenaventura | San Buenaventura | Ventura (but the official name is still San Buenaventura)
Misión San Fernando Rey de España | San Fernando | Mission Hills (neighborhood of Los Angeles); the City of San Fernando is less than a mile away
Pueblo de Nuestra Señora la Reina de los Ángeles del Río de Porciúncula | Pueblo de los Angelos | Los Angeles
Misión San Juan Capistrano | San Juan | San Juan Capistrano
Misión San Luis Rey de Francia | San Luis | Oceanside (mission seized by the U.S. Army until 1865 and fell into disuse)
Misión San Diego de Alcalá | San Diego | San Diego
|
[
"When the United States acquired the territory comprising Arizona and New Mexico by treaty with Mexico in 1848, those lands not already privately owned, including Spanish and Mexican land grants, nor reserved by treaty for the various Indian tribes, became a part of the \"public domain\" and open under various laws to settlement, purchase, and use.\n",
"When Mexico achieved its independence from the Kingdom of Spain and its Spanish Empire in 1821, what is now Arizona became part of its Territory of \"Nueva California,\" (\"New California\"), also known as \"Alta California\" (\"Upper California\"). Descendants of ethnic Spanish and mestizo settlers from the colonial years still lived in the area at the time of the arrival of later European-American migrants from the United States.\n",
"When the Spanish and Mexican territories were incorporated as part of the United States, their inhabitants automatically acquired American citizenship. Louisiana (which was Spanish between 1762 and 1800, when Spain gave back the territory to France) was ceded to the US by France in 1803, Florida was sold by Spain in 1819 and the Southwest passed to the US after the Mexican–American War (1846–48) by the terms of the Guadalupe Hidalgo Treaty, while Texas separated from Mexico in 1836 and was annexed by the United States on December 29, 1845.\n",
"When the United States acquired all of present-day Arizona as part of the Gadsden Purchase in 1853, the numerous Mexican mining and ranching settlements still in existence became part of the United States, and American settlers moved into the area.\n",
"The area remained under New Spain's control until September 28, 1821, when the first Mexican Empire claimed ownership. The area was also claimed by the Republic of Texas during this time until the end of the Mexican–American War in 1846–48. The Treaty of Guadalupe Hidalgo in 1848 established the United States as owner of this territory, and Las Cruces was founded in 1849 when the US Army laid out the town plans.\n",
"New Mexico, the new name for the region between Texas and California, became a US territory. The Senate struck out Article X of the Treaty of Guadalupe Hidalgo, which said that vast land grants in New Mexico (nearly always gifts by the local authorities to their friends) would all be recognized. The treaty promised to protect the ownership rights of the heirs of the land grants. The decision to strike down Article X eventually led to court cases in which the US removed millions of acres of land, timber, and water from Mexican-issued land grants and placed them back in the public domain. But, Correia points out that the lands involved had typically never been occupied or controlled by the men who had the grants; most were in Indian-controlled areas.\n",
"In 1825, Arizona was visited by its first non-Spanish Europeans, English trappers. In 1836, the Republic of Texas, which contained the easternmost of the Southwest United States, won its independence from Mexico. In 1845 the Republic of Texas was annexed by the United States, and immediately became a state, bypassing the usual territory phase. The new state still contained portions of what would eventually become parts of other states. In 1846, the Southwest became embroiled in the Mexican–American War, partly as a result of the United States' annexation of Texas. On August 18, 1846, an American force captured Santa Fe, New Mexico. On December 16 of the same year, American forces captured Tucson, Arizona, marking the end of hostilities in the Southwest United States. When the war ended with the Treaty of Guadalupe Hidalgo on February 2, 1848, the United States gained control of all of present-day California, Nevada and Utah, as well as the majority of Arizona, and parts of New Mexico and Colorado (the rest of present-day Colorado, and most of New Mexico had been gained by the United States in their annexation of the Republic of Texas). The final portion of the Southwestern United States came about through the acquisition of the southernmost parts of Arizona and New Mexico through the Gadsden Purchase in 1853.\n"
] |
Books on U.S.-Native American wars
|
I quite enjoyed: Jill Lepore, The Name of War: King Philip’s War and the Origins of American Identity (New York: Vintage Books, 1999).
It covers one of the earlier conflicts to take place and explores some of the different perspectives and sources on the conflict.
|
[
"Jacquin published 20 books, including: \"American Indians, The Indian Policy of the United States (1830–1890)\", and \"The American people: origins, immigration, ethnicity\". These are reference books on the history of Native Americans, including the blending of cultures and the initial conquest of the American West.\n",
"BULLET::::- Morrison, Kenneth M. \"Native Americans and the American Revolution: Historic Stories and Shifting Frontier Conflict.\" In Indians in American History: An Introduction, edited by Frederick E. Hoxie. Arlington Heights, Illinois: Harlan Davidson, 1988.\n",
"In each of the following chapters, Brown provides an in-depth description of a significant post-1860 event in American Western expansion or Native American eradication, focusing in turn on the specific tribe or tribes involved in the event. In his narrative, Brown primarily discusses such tribes as the Navajo Nation, Santee Dakota, Hunkpapa Lakota, Oglala Lakota, Cheyenne, and Apache people. He touches more lightly upon the subjects of the Arapaho, Modoc, Kiowa, Comanche, Nez Perce, Ponca, Ute, and Minneconjou Lakota tribes.\n",
"The History of the Indian Tribes of North America is a three-volume collection of Native American biographies and accompanying lithograph portraits originally published in the United States from 1836 to 1844 by Thomas McKenney and James Hall. The majority of the portraits were first painted in oil by Charles Bird King. McKenney was working as the US Superintendent of Indian Trade and would head the Office of Indian Affairs, both then within the War Department. He planned publication of the biographical project to be supported by private subscription, as was typical for publishing of the time.\n",
"BULLET::::- \"Wars over Buffalo: Stories vs. Stories on the Northern Plains,\" in \"Native Americans and the Environment: Perspectives on the Ecological Indian\", Michael Harkin and David Rich Lewis, eds. (Lincoln: University of Nebraska Press, 2007): 153-72\n",
"The book consists primarily of the tribal histories of seven different tribes. Among the incidents it depicts is the eradication of Praying Town Indians in the colonial period, despite their recent conversion to Christianity, because it was assumed that all Indians were the same. Her book brought to light the moral injustices enacted upon the Native Americans as it chronicled the ruthlessness of white settlers in their greed for land, wealth, and power.\n",
"His newest book,\"The War That Made America: A Short History of the French and Indian War\" (Viking) is a companion to the four-hour PBS series \"The War that Made America,\" which was broadcast January 18 and 25, 2006. The series and book were released to coincide with the 250th anniversary of the French and Indian War, organized by French and Indian War 250 Inc., as part of a collaborative effort with a variety of museums, historic sites and educational workshops spanning several states.\n"
] |
municipal fiber internet. is it funded by the government or is funded by taxes? or do you just pay for it like you would for any other service (i.e. comcast, xfinity, etc...)? how does a town go about getting it (that is if they are in a state that doesn't ban it)?
|
As the name suggests Municipal Fiber Internet is provided by the municipality (local government). The organization and funding of this is up to the municipality as is the same for any municipal utility like water, sewage and roads. It is not uncommon for the local taxes to pay for some of it however most strive for the utility to become fully self funded. Quite often the municipality only offers financial security to the endevour which is enough to get loans that will be paid back by the subscribers over the lifetime of the infrastructure.
|
[
"By 2013 commercial fiber optics based connections have become commonplace in major city areas usually distributed in house by VDSL2, speeds of 100/10 Mbit/s usually costing about €30/month, and often available by multiple competing ISPs offered in different packaging. More and more rural towns also have fiber available to residents by government supported and resident self organized projects.\n",
"LUS Fiber is a municipally owned subsidiary of Lafayette Utilities System providing Cable Television, Broadband Internet, and Telephone services to the citizens of Lafayette, Louisiana. It is notable for being the first municipally owned company providing Fiber-To-The-Home services in the state of Louisiana, and one of the first municipally owned FTTH companies in the country.\n",
"A fiber-optic backbone links the main buildings and offices. Some locations on the main campus also provide free public wifi. Students pay a one-time fee and have unlimited access throughout the entire semester. However, some students still opt to access the internet through any of the locally available service providers due to speed and filtering issues.\n",
"The traditional telephone companies have historically shown little to no interest in implementing fiber to the premises (FTTP). In 2005 this led 14 local and regional power companies to invest around 1 billion pounds between 2005 and 2013 in building a FTTP infrastructure from scratch. The power companies usually roll out fiber optic cables when they need to dig in an area due to works on subterranean power cables.\n",
"The public corporation also provides fiber optic broadband to private carriers through one of its subsidiary, PREPA Networks. PREPA is also studying the possibility of selling energy to the United States Virgin Islands with the installation of an underwater power cable between Fajardo and the island of St. Thomas—similar to the power cable with which it services its clients in the island municipalities of Vieques and Culebra.\n",
"Fiber-optic Internet access is rolled out on regional scale, encompassing part of a province or a municipality. Deployment is comparable to local-loop unbundling: one party invests in the physical network on which other parties can provide their services. At the end of 2010, fiber-optic Internet was available in 205 out of 408 municipalities. The number of homes passed was 714,600 from a total of 7.386 million.\n",
"Municipal broadband deployments are broadband Internet access services provided either fully or partially by local governments. Common connection technologies include unlicensed wireless (Wi-Fi, wireless mesh networks), licensed wireless (such as WiMAX), and fiber optic cable. Although many cities previously deployed Wi-Fi based solutions, municipal fiber-to-the-home networks are becoming more prominent because of increased demand for modern audio and video applications, which are increasing bandwidth requirements by 40% per year.\n"
] |
why do salt water and fresh water bodies stay seperate
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Land for the most part. Lakes are fed by rainfall, and they occur most often in mountain valleys. Rain falls down the mountainsides making creeks and rivers that feed into the lake, and the water has no where else to go. When rivers feed into the ocean the fresh water mixes and eventually becomes salt water. This influx of fresh water is offset by evaporation, which becomes clouds, which rains to create the fresh water in the first place.
|
[
"The presence of common salt, sodium chloride, helps to preserve salted fish, through inhibition of bacterial growth. When the solution of salt, or brine, is more concentrated—specifically, has a lower water potential—than the fluid of the fish tissue, osmosis will occur. Water molecules will pass from the fish tissue (higher water potential) into the brine (lower water potential) until the water molecules in these two solutions are evenly distributed. This is known as a hypertonic environment. Most bacteria cannot survive in such an environment, as their cells shrink and normal biological function cannot continue, eventually terminating in lysis. This lends the antiseptic properties, and hence preservational power, of salt.\n",
"Salting is used because most bacteria, fungi and other potentially pathogenic organisms cannot survive in a highly salty environment, due to the hypertonic nature of salt. Any living cell in such an environment will become dehydrated through osmosis and die or become temporarily inactivated.\n",
"Water bodies that are not highly concentrated in salts are referred to as 'fresh water' bodies. Fresh water may run through lakes, rivers and streams, to name a few; but it is most prominently found in the frozen state or as soil moisture or buried deep underground. Fresh water is not only important for the survival of humans, but also for the survival of all the existing species of animals, plants.\n",
"Salt is expensive to remove from water, and salt content is an important factor in water use (such as potability). Increases in salinity have been observed in lakes and rivers in the United States, due to common road salt and other salt de-icers in runoff.\n",
"Next consider the example of water with salt. The water surface is less salty than bulk, so whenever the water's surface area is increased, it is necessary to remove salt molecules from the new surface and push them into bulk. If the concentration of salt is increased a bit (raising the salt's chemical potential), it becomes harder to push away the salt molecules. Since it is now harder to create the new surface, the surface tension is higher. The general principle is:\n",
"Although all water bodies on the surface and in aquifers contain dissolved salts, the water must evaporate into the atmosphere for the minerals to precipitate. For this to happen, the water body must enter a restricted environment where water input into this environment remains below the net rate of evaporation. This is usually an arid environment with a small basin fed by a limited input of water. When evaporation occurs, the remaining water is enriched in salts, and they precipitate when the water becomes supersaturated.\n",
"Salt lakes form when the water flowing into the lake, containing salt or minerals, cannot leave because the lake is endorheic (terminal). The water then evaporates, leaving behind any dissolved salts and thus increasing its salinity, making a salt lake an excellent place for salt production. High salinity will also lead to a unique halophilic flora and fauna in the lake in question; sometimes, in fact, the result may be an absence or near absence of life near the salt lake.\n"
] |
Im interested in theory of pre-historic advanced civilizations is there any reading material that you could recommend?
|
Hey there!
You're right that it's not a commonly accepted theory, and for good reason. There's no evidence. Most arguments for it are based on "We don't know anything about this era.. So it could be?" This mentality hardly lends itself to any kind of scholarly research, which is based on making conclusions from observations. While I can recommend some good books in why the "lost ancient super-civ" trope is so prevalent in the West, or on what excavations reveal about the earth during the era of these hypothetical civs, if you would like, but I have never seen a book with anything resembling a scientific approach that takes ancient advanced civs seriously.
|
[
"In the book \"Did the Gods wear shoes\" the author explored the possible existence of prior civilizations. In his sequel \"They who came before us\" he provides the basis for that possibility. The book focuses on prehistoric mason works around the world. The author uses many detailed pictures along with personal observations to establish an alternative to mainstream historical believes. \n",
"Ancient science and technology is also a crucial theme. The book explores the great scientific advancement made in Ancient India investigating the technological literature and artifacts believed to be far more futuristic than present day gizmos. \"The Book Geeks\" review states that \"Satyarth Nayak has taken our rich ancient knowledge of science and converted it into a historical fiction\".\n",
"\"Obsolete objects in the literary imagination: ruins, relics, rarities, rubbish, uninhabited places, and hidden treasures\", text first published in Italian in 1993, is considered Francesco Orlando's magnum opus. Therein, he posits that the theoretical effort of defining literature is analogous to the passionate reading of texts in the Western tradition, from Antiquity to the 19th century.\n",
"Unrelated to the geography but important to some modelers is current evidence of ancient writing. They surmise, there are only two regions in the New World showing the high degree of ancient civilization required by the text of the Book of Mormon. One of these locations is centered in South America in the region once occupied by the Inca civilization. The other is centered in Mesoamerica in the region once occupied by the Maya and the Olmec civilizations. Of the two, only the civilizations in the Mesoamerican region are known to have had a sophisticated form of writing. One LDS researcher, however, points out that even though Central America bore a large population during the Book of Mormon time period, there is no evidence of a large population matching the description of Nephite civilization existing there. Therefore, \"Mesoamerican settings are not more favorable towards the Book of Mormon demographically, than Joseph Smith's American Israelite setting among the mound builders.\" As to the written language of the Nephite people, it was anticipated that their writing \"upon anything save it be upon plates must perish and vanish away ...\"\n",
"Apparently, they made little use of printed materials that could be read in a world without advanced technology. Most knowledge of history and the larger universe was therefore lost, the remainder preserved by oral tradition in \"Chants\" and stories.\n",
"Among his publications are \"The Great Libraries\" (2000), the five volumes \"History of the Library in Western Civilization\", Oak Knoll Press (2001-2013) and the \"Books and Ideas. The Library of Plato and of the Academy\", Oak Knoll Press (2013).\n",
"BULLET::::- \"Perspectives from the Past Primary Sources in Western Civilizations\". W.W. Norton & Company. New York – London. College Book, 2005 –Third Edition (Volume 2), pages 840 (Lyubov Sirota: pages 828 – 832)\n"
] |
how powerful does a nuclear warhead have to be to destroy our planet?
|
Planets are pretty big thing and pretty hard to destroy.
Even if you somehow managed to shatter a planet to pieces the pieces would just be drawn back to each other to reform a planet unless you pushed the pieces very, very hard away from each other.
There is a theory that Earth was impacted by a very large and fast object very early in its development and that the impact was energetic enough to push out a massive amount of molten rock and debris that eventually formed our moon.
That was literally an earth shattering kaboom and the planet still was only changed but not destroyed in the process.
Wikipedia says that the largest nuclear explosion ever was when the Russian tested their Tsar bomb. It was theoretical a 100 megaton bomb but they tested it at 50 mt which works out to be about 2.1×10^17 J.
Wikipedia also gives the energy released by the asteroid that killed all the dinosaurs (except birds) as 5×10^23 J. This means that impact was about 2 million times stronger than the strongest atomic bomb and while it certainly ruined the day for everyone a round at the time it didn't destroy the earth or kill all our ancestors (little furry things that they were).
Wikipedia also gives a value for the gravitational binding energy of Earth (which I assume would be needed to overcome to blast the planet apart) as 2×10^32 J. This would be 10^15 (a quadrillion) times higher than the largest nuclear explosion ever.
You can't really imagine a quadrillion times of anything with a human brain, but it is a lot. We can't scale up nuclear bombs that big.
So the Earth is safe from being blown apart by man made nuclear explosion.
That is good.
As the above value for the dinosaur killing impact shows we are probably also safe from completely destroying our own ecosphere on top of the planet. It is much more fragile than the planet itself, but it has survived explosions a million times bigger than anything we ever made and came out fine eventually.
So we won't kill the planet or life on earth.
Humanity is even more fragile than life on earth. The giant impact above killed of all land species bigger than a medium sized dog. That sort of thing would have a good chance of killing of humanity.
Even more fragile is human civilization. You don't need to kill of all humans with the explosion just make it big enough that the survivors will be bombed back into a stone age. That would be still too much for s ingle full yield tsar bomb, but the nuclear powers of the world have enough bombs to be able to confidently cause a collapse of human civilization, with a small but non-zero chance of total human extinction.
The earth will be fine. We won't.
|
[
"The second, a full-scale nuclear war, could consist of large numbers of nuclear weapons used in an attack aimed at an entire country, including military, economic, and civilian targets. Such an attack would almost certainly destroy the entire economic, social, and military infrastructure of the target nation, and would probably have a devastating effect on Earth's biosphere.\n",
"The idea is that the weapon would naturally contain a large kinetic energy because it moves at orbital velocities, around 8 kilometers per second in orbit and 3 kilometers per second or Mach 10 at impact. As the rod would reenter Earth's atmosphere it would lose most of the velocity, but the remaining energy would cause considerable damage. Some systems are quoted as having the yield of a small tactical nuclear bomb. These designs are envisioned as a bunker buster. As the name suggests, the 'bunker buster' is powerful enough to destroy a nuclear bunker. With 6–8 satellites on a given orbit, a target could be hit within 12–15 minutes from any given time, less than half the time taken by an ICBM and without the launch warning. Such a system could also be equipped with sensors to detect incoming anti-ballistic missile-type threats and relatively light protective measures to use against them (e.g. Hit-To-Kill Missiles or megawatt-class chemical laser).\n",
"BULLET::::- In \"Warhammer 40,000\", nuclear weapons are used to cause widespread damage to a planet (the methods collectively being called an \"Exterminatus\", a mass execution of a population through futuristic weapons) and in combat. The nukes must be properly arranged in orbit to create a global firestorm.\n",
"By surrounding a nuclear warhead with dozens of such rods, each rod could be independently aimed to shoot down an enemy missile. A single such warhead might be able to destroy 50 missiles in a radius of a around it. A small fleet of such warheads could seriously disrupt any Soviet attack.\n",
"The Department of Defense predicted that a Titan II missile could eventually carry a warhead with a 35 megaton yield, based on projected improvements. However, that warhead was never developed or deployed. This would have made this warhead one of the most powerful ever, with almost double the power-to-weight ratio of the B41 nuclear bomb.\n",
"The maximum yield of the W54 warhead used in the Special Atomic Demolition Munition (pictured) was 1 kt (1000 tonnes of TNT equivalent). This is actually larger and heavier than the US W48 nuclear shell at 155 mm (6.1 inches) in diameter and 846 mm (33.3 inches) long and weighing 53.5 kg (118 lb), which represents the smallest complete, self-contained physics package to be fielded and had a yield of 72 tonnes of TNT. Nuclear weapons designer Ted Taylor has alleged that a 105 mm (4.1 inch) diameter shell with a mass of 19 kg is theoretically possible. Conversely, reduction beyond the size of the W54 means that linear implosion designs must be employed and neutron reflectors dispensed with (\"bare core\"), so a much larger mass of fissile material is required and explosive yield is reduced dramatically. Taylor's figures represent the minimum size and mass to sustain a prompt criticality but the duration without tamper or neutron reflection would be short. The slope of exponential growth, estimated number of fissions, and specific fissile material are not recorded. Neptunium-236 is fissile and possesses the smallest and lightest critical mass, but isolation of the specific radionuclide makes it an impractical choice. Several other novel fissile materials are known, but U-235 and Pu-239 are the only practical options although two US tests using U-233 (critical mass some 32% less than U235) have taken place.\n",
"Hypothetically, if one were to assume that each side had 100 missiles, with 5 warheads each, and further that each side had a 95 percent chance of neutralizing the opponent's missiles in their silos by firing 2 warheads at each silo, then the side that strikes first can reduce the enemy ICBM force from 100 missiles to about 5 by firing 40 missiles with 200 warheads and keeping the remaining 60 missiles in reserve. Thus the destruction capability is greatly multiplied by MIRV, when the number of enemy silos does not significantly increase.\n"
] |
In the Americas, why are Spanish-speaking countries so small and numerous, but there are two enormous English-speaking countries?
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After Simon Bolivar drove out the Spanish in South America, he was briefly president of much of Spanish-speaking South America. His vision was for it to be a united country. Other political factions felt differently.
Further north, Mexico and Central America were briefly united after independence -- they were all administered as part of New Spain by the Spanish. Then, modern-day Central America was united as one country for a bit before breaking up into different countries like it is today.
The reasons were different from place to place, but generally speaking, despite having the same language and some cultural similarities, there were too many different political factions, different local leaders who wanted power and not enough of a sense of national unity for these big federations to be workable in the long run.
|
[
"Spanish is spoken by approximately 35 million people. The United States has the world's fifth largest Spanish-speaking population, outnumbered only by Mexico, Colombia, Spain, and Argentina; other estimates put the United States at over 50 million, second only to Mexico. Throughout the Southwestern United States, long-established Spanish-speaking communities coexist with large numbers of more recent Hispanophone immigrants. Although many new Latin American immigrants are less than fluent in English, nearly all second-generation Hispanic Americans speak English fluently, while only about half still speak Spanish.\n",
"The most widely spoken language in the Americas is Spanish. The dominant language of Latin America is Spanish, though the most populous nation in Latin America, Brazil, speaks Portuguese. Small enclaves of French-, Dutch- and English-speaking regions also exist in Latin America, notably in French Guiana, Suriname, and Belize and Guyana respectively. Haitian Creole is dominant in the nation of Haiti, where French is also spoken. Native languages are more prominent in Latin America than in Anglo-America, with Nahuatl, Quechua, Aymara and Guaraní as the most common. Various other native languages are spoken with less frequency across both Anglo-America and Latin America. Creole languages other than Haitian Creole are also spoken in parts of Latin America.\n",
"The different varieties of the Spanish language spoken in the Americas are distinct from Peninsular Spanish and Spanish spoken elsewhere, such as in Africa and Asia. Linguistically, this grouping is somewhat arbitrary, akin to having a term for \"overseas English\" encompassing variants spoken in the United States, Canada, Australia, India, New Zealand and Ireland, but not the Island of Britain. There is great diversity among the various Latin American vernaculars, and there are no traits shared by all of them which are not also in existence in one or more of the variants of Spanish used in Spain. A Latin American \"standard\" does, however, vary from the Castilian \"standard\" register used in television and notably the dubbing industry.\n",
"Spanish is the official language in most Hispanic American countries, and it is spoken by the vast majority of the population. Native American languages are widely spoken in Peru, Guatemala, Bolivia, Paraguay and Mexico, and to a lesser degree, in Panama, Ecuador, Colombia, Venezuela, Argentina, and Chile amongst other countries. In some Hispanic American countries, the population of speakers of indigenous languages tend to be very small or even non-existent (e.g. Uruguay). Mexico is possibly the only country that contains the largest variety of indigenous languages than any other Hispanic American country, and the most spoken native language is Nahuatl.\n",
"The Spanish Empire left a huge linguistic, religious, political, cultural, and urban architectural legacy in the Western Hemisphere. With over 470 million native speakers today, Spanish is the second most spoken native language in the world, as result of the introduction of the language of Castile—Castilian, \"\"Castellano\"\" —from Iberia to Spanish America, later expanded by the governments of successor independent republics. In the Philippines, the Spanish–American War (1898) brought the islands under U.S. jurisdiction, with English being imposed in schools and Spanish becoming a secondary official language.\n",
"The United States of America has 41 million people aged five or older that speak Spanish at home, making Spanish the second most spoken language of the United States by far. Spanish is the most studied foreign language in the United States, with about six million students. With over 50 million native speakers, heritage language speakers and second language speakers, the United States now has the second largest Spanish-speaking population in the world after Mexico, although it is not an official language of the country. About half of all American Spanish speakers also assessed themselves as speaking English \"very well\" in the 2000 U.S. Census. This percentage increased to 57% in the 2013-2017 American Community Survey. The United States is among the Spanish-speaking countries that has its own Academy of the Spanish Language.\n",
"Other European languages spoken in Hispanic America include: English, by some groups in Puerto Rico; German, in southern Chile and portions of Argentina, Venezuela, and Paraguay; Italian, in Argentina, Venezuela, and Uruguay; Ukrainian, Polish, and Russian in Argentina; and Welsh, in southern Argentina.\n"
] |
why are eggs almost universally sold in packs of 12? what made farmers agree to sell this way?
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TLDR; Convenience, 1 shilling = 12 pennies, 1 egg = 1 penny. No need to make change.
Under a system that came to be known as English units, which was a combination of old Anglo-Saxon and Roman systems of measurement, eggs were sold by the dozen. It made sense to sell them that way because one egg could be sold for a penny or 12 for a shilling, which was equal to 12 pennies. That system held sway in the American colonies and persisted after the revolution, becoming part of the system known as U.S. customary units. Such units are used for consumer products and in industrial manufacturing.
The British have moved on, adopting a wholly new system of weights and measurements in 1824. But they still mostly sell eggs by the dozen.
Thus, in the United States, a vast majority of eggs are sold by the dozen, half-dozen and other multiples of 12. But in India and parts of Africa, it isn’t unusual to buy eggs by the piece, and in some countries they may be sold by 10s or 8s.
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[
"From the farmer's point of view, eggs used to be practically the same as currency, with general stores buying eggs for a stated price per dozen. Egg production peaks in the early spring, when farm expenses are high and income is low. On many farms, the flock was the most important source of income, though this was often not appreciated by the farmers, since the money arrived in many small payments. Eggs were a farm operation where even small children could make a valuable contribution.\n",
"The Egg Marketing Board was an agricultural marketing organization set up by the British government in December 1956 to stabilise the market for eggs due to a widespread collapse in sales. The Board purchased all the eggs produced in the UK, graded them to a national standard, and then marketed them to shops. Each eggshell was stamped with a small \"lion\" logo as a mark of quality that would be seen by the customer. Egg producers were paid according to the quality of their eggs, less a deduction based on the number of eggs sent to packhouses for administration and advertising. \n",
"In the UK, statistics from the Department for the Environment, Food and Rural Affairs (Defra) indicate that 50% of eggs produced in the UK throughout 2010 were from cages (45% from free-range, 5% from barns). \n",
"Egg yolks and whole eggs store significant amounts of protein and choline, and are widely used in cookery. Due to their protein content, the United States Department of Agriculture formerly categorized eggs as \"Meats\" within the Food Guide Pyramid (now MyPlate). Despite the nutritional value of eggs, there are some potential health issues arising from cholesterol content, salmonella contamination, and allergy to egg proteins.\n",
"The most commonly used bird eggs are those from the chicken, duck, and goose eggs. Smaller eggs, such as quail eggs, are used occasionally as a gourmet ingredient in Western countries. Eggs are a common everyday food in many parts of Asia, such as China and Thailand, with Asian production providing 59 percent of the world total in 2013.\n",
"Egg-laying chickens include the two groups, Bantams and Standards. Often raised as pets, Bantams are the smaller variety of chickens that require less space and feed. These smaller chickens provide smaller eggs, but still produce a large quantity of eggs. Standards rage from heavy to light breeds and produce the average sized eggs.\n",
"In 1977, American egg farmers also began work on an advertising campaign to increase demand for eggs – its first television commercial began airing in 1977, touting the nutritional benefits as \"The Incredible, Edible Egg\" featuring actor James Hampton. In 1993, the American Egg Board launched a new advertising campaign called \"I Love Eggs\", in which the campaign ran from 1993 to 1997. In 1998, the American Egg Board launched another advertising campaign called \"If it ain't eggs, it ain't breakfast, I love eggs\".\n"
] |
What's the advantage of having a long lifespan?
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Human bodies, especially our brains, take a very long time to develop. We "traded off" our speed of evolution in order to get a more complex body/mind.
Part of the reason that huge plants/animals have the longest life spans is so that they don't need as fast of a metabolism to grow to full size. A 1000-kg animal with a 1-year life cycle would have to eat several tons of food in a few months to become an adult. However, a 1000-kg animal with a 50-year life cycle only needs to eat enough food to maintain its current weight, plus a little bit extra for growth.
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[
"One prominent and very popular theory states that lifespan can be lengthened by a tight budget for food energy called caloric restriction. Caloric restriction observed in many animals (most notably mice and rats) shows a near doubling of life span from a very limited calorific intake. Support for the theory has been bolstered by several new studies linking lower basal metabolic rate to increased life expectancy. That is the key to why animals like giant tortoises can live so long. Studies of humans with life spans of at least 100 have shown a link to decreased thyroid activity, resulting in their lowered metabolic rate.\n",
"All of the biological organisms have a limited longevity, and different species of animals and plants have different potentials of longevity. Misrepair-accumulation aging theory suggests that the potential of longevity of an organism is related to its structural complexity. Limited longevity is due to the limited structural complexity of the organism. If a species of organisms has too high structural complexity, most of its individuals would die before the reproduction age, and the species could not survive. This theory suggests that limited structural complexity and limited longevity are essential for the survival of a species.\n",
"Various factors contribute to an individual's longevity. Significant factors in life expectancy include gender, genetics, access to health care, hygiene, diet and nutrition, exercise, lifestyle, and crime rates. Below is a list of life expectancies in different types of countries:\n",
"An issue that arises is whether we should build immense amounts of life that decays fast, or smaller, but still large, populations that last longer. Life-centered biotic ethics suggests that life should last as long as possible.\n",
"As discussed above, on an individual basis, a number of factors correlate with a longer life. Factors that are associated with variations in life expectancy include family history, marital status, economic status, physique, exercise, diet, drug use including smoking and alcohol consumption, disposition, education, environment, sleep, climate, and health care.\n",
"Longevity is a corollary of the existence bias: if existence is good, longer existence should be better. This thinking resembles quasi-evolutionary notions of \"survival of the fittest\", and also the augmentation principle in attribution theory.\n",
"Various species of plants and animals, including humans, have different lifespans. Evolutionary theory states that organisms that, by virtue of their defenses or lifestyle, live for long periods and avoid accidents, disease, predation, etc. are likely to have genes that code for slow aging, which often translates to good cellular repair. One theory is that if predation or accidental deaths prevent most individuals from living to an old age, there will be less natural selection to increase the intrinsic life span. That finding was supported in a classic study of opossums by Austad; however, the opposite relationship was found in an equally prominent study of guppies by Reznick.\n"
] |
Are animals aware of their own shadows and the shadows of other animals and objects?
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I think the best comparison would be to a mirror. It answers the same basic question but is more explicit. Most animals cannot recognize themselves in a mirror although there are a few exceptions, mostly birds and primates.
About half of all magpies, for example, are able to recognize themselves in the mirror. Interestingly enough, they also seem to know what they should look like and when something is different such as a yellow sticker placed on their feathers.
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[
"Mimicry and camouflage enable animals to appear to be other than they are. Prey animals may appear as predators, or \"vice versa\"; both predators and prey may be hard to see (crypsis), or may be mistaken for other objects (mimesis). In Batesian mimicry, harmless animals may appear to be distasteful or poisonous. In automimicry, animals may have eyespots in less important parts of the body than the head, helping to distract attack and increase the chance of survival.\n",
"The artist Abbott Handerson Thayer in his 1909 book \"Concealing-Coloration in the Animal Kingdom\" argued that animals were concealed by a combination of countershading and \"ruptive\" marks, which together \"obliterated\" their self-shadowing and their shape. Thayer explained that:\n",
"Many animals are highly sensitive to motion; for example, frogs readily detect small moving dark spots but ignore stationary ones. Therefore, motion signals can be used to defeat camouflage. Moving objects with disruptive camouflage patterns remain harder to identify than uncamouflaged objects, especially if other similar objects are nearby, even though they are detected, so motion does not completely 'break' camouflage.\n",
"Nocturnal creatures are having an arms race. Their weapons are not offensive or defensive, but espionage equipment. Some use night vision and take full advantage of the moon and the stars in low light, while others use fine-tuned smell and touch senses. There are animals whose ears are more sensitive than any microphone and creatures who observe their surroundings with three-dimensional sonars or electro-magnetic sensors. Some even produce light: a trap that attracts their prey to death.\n",
"Shadow lions live on the planet Maratha. Their fur absorbs all light so they are extremely difficult to see at night. They can 'see' heat, due to their ability to perceive the infra-red spectrum and follow it to catch their prey. In the dark, Ildirans separated from other Ildirans often mistake these creatures for the Shana Rei. They are ruthless carnivores which demonstrate no fear.\n",
"Most animals react to seeing their reflection as if encountering another individual they do not recognize. An experiment with capuchins shows that they react to a reflection as a strange phenomenon, but not as if seeing a strange capuchin.\n",
"In evolutionary biology, mimicry in vertebrates is mimicry by a vertebrate of some model (an animal, not necessarily a vertebrate), deceiving some other animal, the dupe. Mimicry differs from camouflage as it is meant to be seen, while animals use camouflage to remain hidden. Visual, olfactory, auditory, biochemical, and behavioral modalities of mimicry have been documented in vertebrates.\n"
] |
Other than living in a simulation, what other possible implications does this have?
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He published an article about this in *Physics World*, 2010:
[Symbols of Power: Adinkras and the Nature of Reality](_URL_0_)
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[
"Bostrom argues that \"if\" \"the fraction of all people with our kind of experiences that are living in a simulation is very close to one\", \"then\" it follows that we probably live in a simulation. Some philosophers disagree, proposing that perhaps \"Sims\" do not have conscious experiences the same way that unsimulated humans do, or that it can otherwise be self-evident to a human that they are a human rather than a Sim. Philosopher Barry Dainton modifies Bostrom's trilemma by substituting \"neural ancestor simulations\" (ranging from literal brains in a vat, to far-future humans with induced high-fidelity hallucinations that they are their own distant ancestors) for Bostrom's \"ancestor simulations\", on the grounds that every philosophical school of thought can agree that sufficiently high-tech neural ancestor simulation experiences would be indistinguishable from non-simulated experiences. Even if high-fidelity computer Sims are never conscious, Dainton's reasoning leads to the following conclusion: either the fraction of human-level civilizations that reach a posthuman stage and are able and willing to run large numbers of neural ancestor simulations is close to zero, or we are in some kind of (possibly neural) ancestor simulation.\n",
"Epistemologically, it is not impossible to tell whether we are living in a simulation. For example, Bostrom suggests that a window could \"pop up\" saying: \"You are living in a simulation. Click here for more information.\" However, imperfections in a simulated environment might be difficult for the native inhabitants to identify and for purposes of authenticity, even the simulated memory of a blatant revelation might be purged programmatically. Nonetheless, should any evidence come to light, either for or against the skeptical hypothesis, it would radically alter the aforementioned probability.\n",
"Simulation theory argues that mental simulations do not fully exclude the external information that surrounds the user. Rather that the mediated stimuli are reshaped into imagery and memories of the user in order to run the simulation. It explains why the user is able to form these experiences without the use of technology, because it points to the relevance of construction and internal processing.\n",
"BULLET::::- Simulation is a term that can be defined as a virtual representation of reality. For example, according to New Media and Visual Culture, virtually, things seem real based on experience, but they are not real because they have not actually happened. French theorist, Jean Baudrillard, believed that simulation was the modern stage of simulacrum.\n",
"Bostrom goes on to use a type of anthropic reasoning to claim that, \"if\" the third proposition is the one of those three that is true, and almost all people with our kind of experiences live in simulations, \"then\" we are almost certainly living in a simulation.\n",
"Live, Virtual, & Constructive (LVC) Simulation is a broadly used taxonomy for classifying Models and Simulation (M&S). However, categorizing a simulation as a live, virtual, or constructive environment is problematic since there is no clear division between these categories. The degree of human participation in a simulation is infinitely variable, as is the degree of equipment realism. The categorization of simulations also lacks a category for simulated people working real equipment.\n",
"They can help to understand the connections between factors and events and to examine their dynamics. Simulation is a process that represents a structure and change of a system. In simulation some aspects of reality are duplicated or reproduced, usually within the model. \n"
] |
What role did Persia and Persians play in Greek mythology?
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There are no Greek Myths relating to the Persians or Persia directly.
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[
"According to Herodotus, the Persians numbered 300,000 and were accompanied by troops from Greek city states that supported the Persian cause (including Macedonia, Thessaly and Thebes). Herodotus admits that no one counted the Greek allies of the Achaemenids, but he guesses that there were about 50,000 of them. Mardonius' troops consisted of not only Persians and Medes, but also Bactrians, Scythians, Indians, Boeotians, Locrians, Malians, Thessalians, Macedonians, Thracians, and 1,000 Phocians. Herodotus described the composition of the principal troops of Mardonius:\n",
"\"The Persians\" was popular in the Roman Empire and Byzantine Empire, who also fought wars with the Persians, and its popularity has endured in modern Greece. According to Anthony Podlecki, during a production at Athens in 1965 the audience \"rose to its feet en masse and interrupted the actors' dialogue with cheers.\"\n",
"Repeatedly defeated in battle by the Greeks, and plagued by internal rebellions which hindered their ability to fight the Greeks, after 450 BC Artaxerxes and his successors adopted a policy of divide-and-rule. Avoiding fighting the Greeks themselves, the Persians instead attempted to set Athens against Sparta, regularly bribing politicians to achieve their aims. In this way, they ensured that the Greeks remained distracted by internal conflicts, and were unable to turn their attentions to Persia. There was no open conflict between the Greeks and Persia until 396 BC, when the Spartan king Agesilaus briefly invaded Asia Minor; as Plutarch points out, the Greeks were far too busy overseeing the destruction of their own power to fight against the \"barbarians\".\n",
"Repeatedly defeated in battle by the Greeks, and plagued by internal rebellions that hindered their ability to fight the Greeks, after 449 BC, Artaxerxes I and his successors instead adopted a policy of divide-and-rule. Avoiding fighting the Greeks themselves, the Persians instead attempted to set Athens against Sparta, regularly bribing politicians to achieve their aims. In this way, they ensured that the Greeks remained distracted by internal conflicts, and were unable to turn their attentions to Persia. There was no open conflict between the Greeks and Persia until 396 BC, when the Spartan king Agesilaus briefly invaded Asia Minor; as Plutarch points out, the Greeks were far too busy overseeing the destruction of their own power to fight against the \"barbarians\".\n",
"In the 5th century, the Achaemenid Empire of Persia began a series of invasions against Ancient Greece. Because of this, some scholars believe that on most 5th-century Greek art, the Persians were shown allegorically, through the figure of centaurs and Amazons.\n",
"The Greco-Persian Wars had their roots in the conquest of the Greek cities of Asia Minor, and particularly Ionia, by the Achaemenid Persian Empire of Cyrus the Great shortly after 550 BC. The Persians found the Ionians difficult to rule, eventually settling for sponsoring a tyrant in each Ionian city. While Greek states had in the past often been ruled by tyrants, this was a form of arbitrary government that was on the decline. By 500 BC, Ionia appears to have been ripe for rebellion against these Persian clients. The simmering tension finally broke into open revolt due to the actions of the tyrant of Miletus, Aristagoras. Attempting to save himself after a disastrous Persian-sponsored expedition in 499 BC, Aristagoras chose to declare Miletus a democracy. This triggered similar revolutions across Ionia, extending to Doris and Aeolis, beginning the Ionian Revolt.\n",
"The Greco-Persian Wars had their roots in the conquest of the Greek cities of Asia Minor, and in particular Ionia, by the Persian Empire of Cyrus the Great shortly after 550 BC. The Persians found the Ionians difficult to rule, eventually settling for sponsoring a tyrant in each Ionian city. While Greek states had in the past often been ruled by tyrants, this was a form of government on the decline. By 500 BC, Ionia appears to have been ripe for rebellion against these Persian place-men. The simmering tension finally broke into open revolt due to the actions of the tyrant of Miletus, Aristagoras. Attempting to save himself after a disastrous Persian-sponsored expedition in 499 BC, Aristagoras chose to declare Miletus a democracy. This triggered similar revolutions across Ionia, and indeed Doris and Aeolis, beginning the Ionian Revolt.\n"
] |
Could someone explain the differences between and advantages/disadvantages of the different antiseptics? iodine vs alcohol vs peroxide, vs etc?
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[Here](_URL_0_) is a well-cited review of several antiseptics, including the ones you mentioned :)
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[
"BULLET::::- Iodine is usually used in an alcohol solution (called tincture of iodine) or as Lugol's iodine solution as a pre- and postoperative antiseptic. Some studies do not recommend disinfecting minor wounds with iodine because of concern that it may induce scar tissue formation and increase healing time. However, concentrations of 1% iodine or less have not been shown to increase healing time and are not otherwise distinguishable from treatment with saline. Novel iodine antiseptics containing povidone-iodine (an iodophor, complex of povidone, a water-soluble polymer, with triiodide anions I, containing about 10% of active iodine) are far better tolerated, do not negatively affect wound healing, and leave a deposit of active iodine, thereby creating the so-called \"remnant\", or persistent, effect. The great advantage of iodine antiseptics is their wide scope of antimicrobial activity, killing all principal pathogens and, given enough time, even spores, which are considered to be the most difficult form of microorganisms to be inactivated by disinfectants and antiseptics.\n",
"The use of some antimicrobials such as triclosan, is controversial because it may lead to antimicrobial resistance. The use of chlorine bleach and alcohol disinfectants does not cause antimicrobial resistance as it denatures the protein of the microbe upon contact.\n",
"In order to eliminate this problem, it is imperative to apply antiseptics at once. Hydrogen peroxide (a near-universal toxin) is not recommended for this task as it increases inflammation and impedes healing. Dressings with cadexomer iodine, silver, or honey have been shown to penetrate bacterial biofilms. Systemic antibiotics are not recommended in treating local infection in a pressure ulcer, as it can lead to bacterial resistance. They are only recommended if there is evidence of advancing cellulitis, bony infection, or bacteria in the blood.\n",
"Historically hydrogen peroxide was used for disinfecting wounds, partly because of its low cost and prompt availability compared to other antiseptics. It is now thought to inhibit healing and to induce scarring because it destroys newly formed skin cells. Only a very low concentration of HO can induce healing, and only if not repeatedly applied. Surgical use can lead to gas embolism formation. Despite this, it is still used for wound treatment in many countries but is also prevalent as a major first aid antiseptic in the United States.\n",
"Medical use of iodine compounds (i.e. as a contrast agent) can cause anaphylactic shock in highly sensitive patients, presumably due to sensitivity to the chemical carrier. Cases of sensitivity to iodine compounds should not be formally classified as iodine allergies, as this perpetuates the erroneous belief that it is the iodine to which patients react, rather than to the specific allergen. Sensitivity to iodine-containing compounds is rare but has a considerable effect given the extremely widespread use of iodine-based contrast media.\n",
"Practitioners of alternative medicine have advocated the use of hydrogen peroxide for various conditions, including emphysema, influenza, AIDS and cancer, although there is no evidence of effectiveness and in some cases it may even be fatal.\n",
"According to a 2011 review, there have been few studies on the efficacy of Proactiv. A 2011 \"Consumer Reports\" study compared Proactiv with two less expensive types of benzoyl peroxide, AcneFree and OXY Maximum, and found all three to be equally effective. The US Food and Drug Administration warned in 2014 that over-the-counter acne treatments can cause severe irritation, as well as rare but life-threatening allergic reactions.\n"
] |
how does "lottery wheeling" work?
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The only part of the Wikipedia article you need to pay attention to says that wheeling does not change the expectation value of the ticket. That means that the probability of paying more for the ticket than you win is still nearly 100% and the more you play, the more you are expected to lose.
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[
"Lottery wheeling (also known as lottery system, lottery wheel, lottery wheeling system) is used by individual players and syndicates to distribute a subset of the possible lottery numbers across multiple tickets to ensure that at least one of these tickets will contain a winning combination if several draws are in this subset. For example, in a pick 5 lottery, a lottery system with a subset of 9 selections and a \"3 if 3\" guarantee means that a 3-win payout is ensured when three of these 9 selections are among the five numbers drawn.\n",
"A lottery wheeling system acts as a single ticket in terms of a particular guarantee, but allows playing with a larger set of numbers than will be drawn in the lottery. In contrast, a single ticket in a pick 6 lottery guarantees a 4-win if four of the player's numbers are drawn from a subset of only the six selections on that ticket. A lottery system with, say, 10 selections and the same guarantee would require at least 20 tickets but ensures a 4-win if four of the player's numbers are drawn from a subset of ten selections. The term \"wheeling\" comes from the cyclic permutation method of construction, as in the following example: a \"pick 6, 9 numbers, 4 if 5\" guarantee system in 3 combinations, where the chosen subset are the integers 1 to 9:\n",
"Lottery Wheels were in use in Europe and imported to Canada and the USA in the 1970s. Wheeling systems usually try to guarantee a minimum number of wins given that draws fall in the set of the player's numbers. From a mathematical standpoint 'wheeling' has no impact on the expected value of a given ticket, but reduces the payout variance across all tickets, compared to making independent random selections for each ticket (from the same subset of winning numbers). Smoothing out the wins in this way is popular in syndicates. Wheeling can be bundled with lottery prediction software and other tools which supposedly improve the odds but are often based on the Gambler's Fallacy or plain misunderstanding or misrepresentation of statistics.\n",
"\"The Lottery\" pokes fun at the excitement surrounding the lottery held during the fall of 1731. In particular, Fielding mocks both those who sell or rent tickets and those who purchase the tickets. The portrayal of the ticket vendors emphasised the potential for deceit and the amount of scams that were possible. It also attacked how the vendors interacted with each other in a competitive spirit. Fielding expects that his audience understands how the lottery operated and focused on how gambling cannot benefit gamblers. \n",
"Lottery betting is the activity of predicting the results of a lottery draw and placing a wager on the outcome. Lottery betting (also known as lotto betting) is a form of online gambling, run by licensed betting firms, where players place bets on the outcome of lottery draws instead of buying physical or online tickets via official lottery operators. \n",
"The classic lottery is a drawing in which each contestant buys a combination of numbers. Each combination of numbers, or \"play\", is usually priced at $1. Plays are usually non-exclusive, meaning that two or more ticket holders may buy the same combination. The lottery organization then draws the winning combination of 5-8 numbers, usually from 1 to 50, using a randomized, automatic ball tumbler machine.\n",
"Lottery scheduling is a probabilistic scheduling algorithm for processes in an operating system. Processes are each assigned some number of lottery tickets, and the scheduler draws a random ticket to select the next process. The distribution of tickets need not be uniform; granting a process more tickets provides it a relative higher chance of selection. This technique can be used to approximate other scheduling algorithms, such as \n"
] |
How can I have 80 billion direct ancestors going back to just the 13th Century?
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You were made by 2 people, who were made by 4 people, who were made by 8 people... etc. Not including siblings.
|
[
"In 1994, near the Awash River in Ethiopia, Tim D. White found the then-oldest known human ancestor: 4.4 million-year-old \"Ar. ramidus\". A fossilized almost complete skeleton of a female hominin which he named \"Ardi\", it took nearly 15 years to safely excavate, preserve, and describe the specimen and to prepare publication of the event.\n",
"According to Behar et. al the woman who founded this line was estimated to have lived between 2,400 and 7,000 years ago. From a neolithic burial at the Bom Santo cave (near Lisbon/Portugal), however, we know that H10e has existed already at 3735 BCE ± 45 years. Hence H10e is at least 5,753 years old.\n",
"BULLET::::- 10,000–5,000 years ago (8,000–3,000 BC) Identical ancestors point: sometime in this period lived the latest subgroup of human population consisting of those that were all common ancestors of all present day humans, the rest having no present day descendants.\n",
"The oldest known ancestor is one Gillion de l'Annoit who lived in the 13th century. Many of his descendants were members of the Order of the Golden Fleece. They played a prominent role in Flanders during the Middle Ages. Different family branches, and lines existed, amongst the Lords of Beaurepaire, Clervaux, princes of Sulmona and Princes of Rheina-Wolbecq.\n",
"A 2013 study in \"Nature\" reported that DNA found in the 24,000-year-old remains of a young boy from the archaeological Mal'ta-Buret' culture suggest that up to one-third of indigenous Americans' ancestry can be traced back to western Eurasians, who may have \"had a more north-easterly distribution 24,000 years ago than commonly thought\" \"We estimate that 14 to 38 percent of Amerindian ancestry may originate through gene flow from this ancient population,\" the authors wrote. Professor Kelly Graf said,\n",
"Their historically attested male-line ancestors are known as far back as the 14th century. The earliest historical ancestor was the knight Birger Knutsson, also known as \"Birghe Trulle\". The earliest known generations held the estate of Bo in Småland, Sweden. Birger Birgersson, High Councillor of Sweden (d 1471), inherited Bergkvara castle from his half-brother.\n",
"A 2013 study in \"Nature\" reported that DNA found in the 24,000-year-old remains of a young boy from the archaeological Mal'ta-Buret' culture suggest that up to one-third of the indigenous Americans may have ancestry that can be traced back to western Eurasians, who may have \"had a more north-easterly distribution 24,000 years ago than commonly thought\". \"We estimate that 14 to 38 percent of Native American ancestry may originate through gene flow from this ancient population\", the authors wrote. Professor Kelly Graf said,\n"
] |
the difference between public and private sector labor unions
|
A public sector labor union is a union comprised of government workers. A private sector labor union is a union comprised of private employees.
The biggest difference is that public sector labor unions largely negotiate with other government employees or politicians for their contracts. Private sector employees negotiate with the company's counsel.
Private sector unions negotiate for a larger share of the profits they help create. Public sector unions negotiate for more tax funds. It is for this reason that even FDR (extremely liberal president) was highly against the idea of public sector unions.
|
[
"In the United States, labor relations in the private sector is regulated by the National Labor Relations Act. Public sector labor relations is regulated by the Civil Service Reform Act of 1978 and various pieces of state legislation. In other countries, labor relations might be regulated by law or tradition. \n",
"BULLET::::- Public employee unions represent workers. Since contract negotiations for these workers are dependent on the size of government budgets, this is the one segment of the labor movement that can actually contribute directly to the people with ultimate responsibility for its livelihood. While their giving pattern matches that of other unions, public sector unions also concentrate contributions on members of Congress from both parties who sit on committees that deal with federal budgets and agencies.\n",
"Private sector unions are regulated by the National Labor Relations Act (NLRA), passed in 1935 and amended since then. The law is overseen by the National Labor Relations Board (NLRB), an independent federal agency. Public sector unions are regulated partly by federal and partly by state laws. In general they have shown robust growth rates, because wages and working conditions are set through negotiations with elected local and state officials.\n",
"The National Labor Relations Act of 1935 authorized trade unions in the private sector to be established to represent employees in collective bargaining for wages and other benefits from employers. Frequently, unions also engage in political activity to support their goals by donating to political campaigns. These activities are paid for through fees and dues collected from its members. Some unions are also able to collect fees from non-members in the same workplace through agency shop or union equity agreements. Within the public sector (unions that include members working for state and local governments), which are governed by individual state laws, the use of such agreements had been previously allowed by the Supreme Court in \"Abood v. Detroit Board of Education\", , which determined that as long as such dues collected from non-members was used only for the union's purposes of collective bargaining, contract administration, and grievance adjustment, it did not violate the non-members' First Amendment of the United States Constitution. It was also determined in \"Marquez v. Screen Actors Guild Inc.\", , that private-sector unions have a duty of fair representation to all workers in a bargaining unit under the National Labor Relations Act, and that unions were allowed to negotiate agreements which state that \"membership\" was required as a condition of continued employment, even though the Taft-Hartley Act of 1947 had outlawed agreements requiring formal union membership. About 22 states have unions with these collective agreements in place that apply to their public sector workers.\n",
"Unions also strongly influence job security. Jobs that traditionally have a strong union presence such as many government jobs and jobs in education, healthcare and law enforcement are considered very secure while many non-unionized private sector jobs are generally believed to offer lower job security, although this varies by industry and country.\n",
"Public sector worker unions are governed by labor laws and labor boards in each of the 50 states. Northern states typically model their laws and boards after the NLRA and the NLRB. In other states, public workers have no right to establish a union as a legal entity. (About 40% of public employees in the USA do not have the right to organize a legally established union.)\n",
"Labor unions are legally recognized as representatives of workers in many industries in the United States. Their activity today centers on collective bargaining over wages, benefits, and working conditions for their membership, and on representing their members in disputes with management over violations of contract provisions. Larger unions also typically engage in lobbying activities and electioneering at the state and federal level.\n"
] |
given how hard it is to start and run a successful small business nowadays, how were so many immigrants able to come here with nothing, and and still start up businesses in the cities where they settled?
|
In the old days there were extremely few regulations, and they were not well enforced. If you wanted (for example) to buy some stuff and sell it retail from a wagon on the street, you could just start doing that.
|
[
"Immigrants have been linked to greater invention and innovation in the US. According to one report, \"immigrants have started more than half (44 of 87) of America's startup companies valued at $1 billion or more and are key members of management or product development teams in over 70 percent (62 of 87) of these companies.\" Foreign doctoral students are a major source of innovation in the American economy. In the United States, immigrant workers hold a disproportionate share of jobs in science, technology, engineering, and math (STEM): \"In 2013, foreign-born workers accounted for 19.2 percent of STEM workers with a bachelor's degree, 40.7 percent of those with a master's degree, and more than half—54.5 percent—of those with a Ph.D.\"\n",
"Many of these immigrants came to America expecting to work in the mines just long enough to save money, buy land, and return to the farming lifestyle they had known in Europe. Once they became part of the company-owned system, however, very few were able to escape the years of poverty and hardship that faced them.\n",
"Immigrants have been linked to greater invention and innovation in the US. According to one report, \"immigrants have started more than half (44 of 87) of America's startup companies valued at $1 billion dollars or more and are key members of management or product development teams in over 70 percent (62 of 87) of these companies.\" One analysis found that immigrant-owned firms had a higher innovation rate (on most measures of innovation) than firms owned by U.S.-born entrepreneurs. Research also shows that labor migration increases human capital. Foreign doctoral students are a major source of innovation in the American economy. In the United States, immigrant workers hold a disproportionate share of jobs in science, technology, engineering, and math (STEM): \"In 2013, foreign-born workers accounted for 19.2 percent of STEM workers with a bachelor's degree, 40.7 percent of those with a master's degree, and more than half—54.5 percent—of those with a Ph.D.\"\n",
"León Rodríguez, Director of U.S. Citizenship and Immigration Services at the time the International Entrepreneur Rule was published, stated, “America’s economy has long benefitted from the contributions of immigrant entrepreneurs, from Main Street to Silicon Valley”. Historically, immigrant entrepreneurs have played a pivotal role in developing the U.S. economy, particularly in the technology sector. In the years of 1998-2006, 14.76% of all patent applications in the United States had at least one immigrant involved as a lone or co-founder, with the majority of these patents having roots in California and New Jersey. In all American technology and engineering businesses created in the U.S. between 1995-2005, one-quarter of them had an immigrant as a key founder. In 2012, immigrant tech-founded companies employed over 550,000 people and generated close to 70 billion dollars in sales. Over 40% of current Fortune 500 companies were established by immigrants or children of immigrants. President Obama’s last State of the Union Address summarized the importance of international entrepreneurs in the US: “America is every immigrant and entrepreneur from Boston to Austin to Silicon Valley, racing to shape a better world. That’s who we are.”\n",
"As the nation matured, many new immigrants congregated in the cities, hoping to find work, especially along the coast, where the bulk of business was still being done. The number of professional longshoremen grew by thousands.\n",
"Immigrants were pushed out of their homelands by poverty or religious threats, and pulled to America by jobs, farmland and kin connections. They found economic opportunity at factories, mines and construction sites, and found farm opportunities in the Plains states.\n",
"According to one survey of the existing economic literature, \"much of the existing research points towards positive net contributions by immigrant entrepreneurs.\" Areas where immigrant are more prevalent in the United States have substantially more innovation (as measured by patenting and citations). Immigrants to the United States create businesses at higher rates than natives. According to a 2018 paper, \"first-generation immigrants create about 25% of new firms in the United States, but this share exceeds 40% in some states.\" Another 2018 paper links H-1B visa holders to innovation.\n"
] |
How long did it take to create marble sculptures? Weeks, months, or years?
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"Months to years, it depends". Many of the famous Renaissance sculptures took between one and three years. Almost three years for Michelangelo's David (september 13th 1501-early spring 1504), about two for Moses, and almost two for the Pietá (1498). Donatello spent more than two years on each of Zuccone, Saint George and Saint Mark, working with several assistants.
Sources: _URL_0_
"Donatello: Sculptor" by John Wyndham Pope-Hennessy
|
[
"The accounts of the construction of the Parthenon make it possible to know that the marble intended for the pediments began to be extracted from the quarries of Mount Pentelikon in 439-438 BC.; sculpture work starting the following year. The accounts also show that excavation and transportation expenses were annual. This could mean that different quarries would have been used each year to obtain the highest possible quality marble The last marble purchases in the quarries are recorded in 434 BC. In the logic of the construction of the building, the sculptures of the pediments had to be installed almost at the very end (before the installation of the roof), probably in 432 BC.\n",
"The extraction of Sivec marble can be dated back 500 BCE and earlier. Extraction flourished under the Roman period when the quarries near the ancient city of Stibera (today Prilep) produced stone for the production of Roman sculptures, as well as replicas of Greek original bronzes. These replicas went to Rome or to other parts of the empire.\n",
"By the classical period, roughly the 5th and 4th centuries, monumental sculpture was composed almost entirely of marble or bronze; with cast bronze becoming the favoured medium for major works by the early 5th century; many pieces of sculpture known only in marble copies made for the Roman market were originally made in bronze. Smaller works were in a great variety of materials, many of them precious, with a very large production of terracotta figurines. The territories of ancient Greece, except for Sicily and southern Italy, contained abundant supplies of fine marble, with Pentelic and Parian marble the most highly prized, along with that from modern Prilep in North Macedonia, and various sources in modern Turkey. The ores for bronze were also relatively easy to obtain. Marble was mostly found around the Parthenon and other major Greek buildings.\n",
"The bust took just over three months to carve. According to Chantelou's diary the process of selecting marble suitable marble blocks took several days to accomplish. While searching for a suitable block of marble to create the bust there was some discussion with members of the court about whether or not Bernini would make a full body statue or a bust. Once potential blocks of marble had been selected, Bernini began by taking drawings (none of which survive) and small clay models of the king. However, it seems that once he had done this initial work, Bernini chose to work only during sittings with the king. His pupil, Giulio Cartari, began work on carving down the chosen block of marble (and would later do much of the drapery work), and then Bernini took over, taking forty days to complete the work. He had hoped to have twenty sittings with the king during the final carving process, but in fact there were thirteen of around one hour each. The bust is modeled heavily after an earlier bust that Bernini made almost a decade prior of Francesco d'Este, the duke of Modena, and other than the fact that Louis' cloak was slightly longer horizontally a person would not be able to tell that one was of higher nobility.\n",
"During the exhibition, many people believed the sculpture to be made of marble, but in fact it was a fibreglass exhibition cast made originally for my exhibition at the Forte di Belvedere in Florence (1963), because of the difficulty of getting a very heavy bronze or marble on to the site. Therefore, so that it could be left as a permanent sculpture in Kensington Gardens, I produced a version in travertine marble which is a very lasting material.\"\n",
"Pliny the Elder, after having described the sculpture of the classical period notes: \"Cessavit deinde ars\" (\"then art disappeared\"). According to Pliny's assessment, sculpture declined significantly after the 121st Olympiad (296–293 BC). A period of stagnation followed, with a brief revival after the 156th (156–153 BC), but with nothing to the standard of the times preceding it.\n",
"The marble statue extant today dates to the late 1st century BC. The lost Greek original on which it is based is thought to have been bronze, and to have been executed around 300 BC, towards the beginning of the Hellenistic era. The provenance of the marble copy is unknown, but it was rediscovered, missing its head, in the early modern era. The head was restored, first in the 16th century and again in the 18th century (in which case the sculptor followed the earlier restoration fairly closely); the restored head was made to look over the shoulder, drawing further attention to the statue's bare buttocks, thereby contributing to its popularity. In the 17th and 18th centuries the statue was identified as Venus and associated with a temple to Aphrodite Kallipygos at Syracuse, discussed by Athenaeus in his \"Deipnosophists\". The statue was copied a number of times, including by Jean-Jacques Clérion and François Barois.\n"
] |
why do doctors flick syringes before injecting someone? is this just a thing they do in tv shows?
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They are checking for air bubbles. Injecting a air bubble into a blood vessel can easily kill a person.
|
[
"Modern use for syringes goes beyond the doctor’s office, hospitals or medical operating rooms. They have evolved into other industries such as for cooking when injecting liquids for fillers in certain foods. Other uses include printers, for re-filling of the cartridges which are often difficult to perform without the use of a syringe with more precise and accurate results. In addition, it can be used to inject glue and other products into places that cannot be reached by a human hand or any other device. They are also used in the sciences such as chemistry, biology and precision experiments where liquids can be dangerous to transport and insert with other devices. Most recently, they are also used to feed animals in zoos and centers of recovery when they are unable to drink it themselves. Its use has become indispensable in multiple areas and proof that her invention has changed all these fields for the better. \n",
"BULLET::::- Labyrinth (1991): A group of children find a discarded syringe and talk about what to do with it. The commercial ends with the message, \"Remember, if you find a needle tell somebody.\" Edited Feb. 14 1991. AGENCY: Cactus Productions Inc.\n",
"The medication is injected subcutaneously twice per day using a filled pen-like device (Byetta), or on a weekly basis with either a pen-like device or conventional syringe (Bydureon). The abdomen is a common injection site.\n",
"A medical aspirator is a suction machine used to remove mucus, blood, and other bodily fluids from a patient. They can be used during surgical procedures but an operating theater is generally equipped with a central system of vacuum tubes. Most aspirators are therefore portable, for use in ambulances and nursing homes, and can run on AC/DC or battery power. They consist of a vacuum pump, a\n",
"There are needle syringes designed to reload from a built-in tank (container) after each injection, so they can make several or many injections on a filling. These are not used much in human medicine because of the risk of cross-infection via the needle. An exception is the personal insulin autoinjector used by diabetic patients.\n",
"The clinician may first use a local anesthetic to numb the cervix. Then, the clinician may use instruments called \"dilators\" to open the cervix, or sometimes medically induce dilation with drugs. Finally, a sterile cannula is inserted into the uterus and attached via tubing to the pump. The pump creates a vacuum which empties uterine contents.\n",
"Medical syringes are sometimes used without a needle for orally administering liquid medicines to young children or animals, or milk to small young animals, because the dose can be measured accurately and it is easier to squirt the medicine into the subject's mouth instead of coaxing the subject to drink out of a measuring spoon.\n"
] |
the difference between single phase and three phase power
|
Both are forms of alternating current (AC)
Alternating current cycles from +120V to -120V, 60 times per second (assuming you live somewhere that uses 120V 60 Hz for mains power)
Single phase power means that all of the power in the wire alternates from +120V to -120V.
Three phase power has three wires, all alternating from +120 to -120, all at the same frequency, but they are offset from each other. Basically, when Phase 1 is at its peak, Phase 2 is in the middle, and Phase 3 is at the bottom. So in 3 phase, there's virtually always a wire at 120V or very close to it. It delivers a steady stream of power, and that makes it much more useful for higher electrical loads.
|
[
"Single-phase generator (also known as single-phase alternator) is an alternating current electrical generator that produces a single, continuously alternating voltage. Single-phase generators can be used to generate power in single-phase electric power systems. However, polyphase generators are generally used to deliver power in three-phase distribution system and the current is converted to single-phase near the single-phase loads instead. Therefore, single-phase generators are found in applications that are most often used when the loads being driven are relatively light, and not connected to a three-phase distribution, for instance, portable engine-generators. Larger single-phase generators are also used in special applications such as single-phase traction power for railway electrification systems.\n",
"A split-phase or single-phase three-wire system is a type of single-phase electric power distribution. It is the AC equivalent of the original Edison three-wire direct-current system. Its primary advantage is that it saves conductor material over a single-ended single-phase system, while only requiring a single phase on the supply side of the distribution transformer.\n",
"A single-phase load may be powered from a three-phase distribution transformer in two ways: by connection between one phase and neutral or by connection between two phases. These two give different voltages from a given supply. For example, on a 120/208 three-phase system, which is common in North America, the phase-to-neutral voltage is 120 volts and the phase-to-phase voltage is 208 volts. This allows single-phase lighting to be connected phase-to-neutral and three-phase motors to be connected to all three phases. This eliminates the need of a separate single phase transformer.\n",
"In electrical engineering, single-phase electric power is the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single-phase distribution is used when loads are mostly lighting and heating, with few large electric motors. A single-phase supply connected to an alternating current electric motor does not produce a rotating magnetic field; single-phase motors need additional circuits for starting (capacitor start motor), and such motors are uncommon above 10 kW in rating.\n",
"In electrical engineering, three-phase electric power systems have at least three conductors carrying alternating current voltages that are offset in time by one-third of the period. A three-phase system may be arranged in delta (∆) or star (Y) (also denoted as wye in some areas). A wye system allows the use of two different voltages from all three phases, such as a 230/400 V system which provides 230 V between the neutral (centre hub) and any one of the phases, and 400 V across any two phases. A delta system arrangement only provides one voltage magnitude, but it has a greater redundancy as it may continue to operate normally with one of the three supply windings offline, albeit at 57.7% of total capacity. Harmonic current in the neutral may become very large if nonlinear loads are connected.\n",
"Power and voltage are specified in the same way as single-phase systems. However, due to differences in what these terms usually represent in three-phase systems, the relationships for the derived units are different. Specifically, power is given as total (not per-phase) power, and voltage is line-to-line voltage.\n",
"The symmetric three-phase systems described here are simply referred to as \"three-phase systems\" because, although it is possible to design and implement asymmetric three-phase power systems (i.e., with unequal voltages or phase shifts), they are not used in practice because they lack the most important advantages of symmetric systems.\n"
] |
can smelling something be unhealthy? like if there's a very bad smell, is there anything dangerous about the act of smelling it?
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Yes. Stuff like paint- and glue fumes can be highly toxic.
I don't think that "regular" bad smells like rotting fish or excrement are dangerous even in large quantities, but both foster a myriad of harmful microbes so the smell is evolution telling you to stay away.
|
[
"Phantosmia (olfactory hallucinations), smelling an odor that is not actually there, and parosmia (olfactory illusions), inhaling a real odor but perceiving it as different scent than remembered, are distortions to the sense of smell (olfactory system) that, in most cases, are not caused by anything serious and usually go away on their own in time. It can result from a range of conditions such as nasal infections, nasal polyps, dental problems, migraines, head injuries, seizures, strokes, or brain tumors. Environmental exposures are sometimes the cause as well, such as smoking, exposure to certain types of chemicals (e.g., insecticides or solvents), or radiation treatment for head or neck cancer. It can also be a symptom of certain mental disorders such as depression, bipolar disorder, intoxication or withdrawal from drugs and alcohol, or psychotic disorders (e.g., schizophrenia). The perceived odors are usually unpleasant and commonly described as smelling burned, foul spoiled, or rotten.\n",
"Merciful anosmia is a condition in which the person is unaware of a foul smell emanating from his own nose. This condition is seen in atrophic rhinitis. In atrophic rhinitis, the turbinates, venous sinusoids, seromucinous glands and nerves undergo atrophy, resulting in a foul smelling discharge. As the nerve fibres sensing smell are also atrophied, the patient is unable to appreciate the foul smell.\n",
"“Imagine the worst, most foul thing you have ever smelled. An overpowering mix of rotting meat, old socks that haven’t been washed for weeks – topped off with the pungent waft of an open sewer. . .Imagine being covered in the stuff as it is liberally sprayed from a water cannon. Then imagine not being able to get rid of the stench for at least three days, no matter how often you try to scrub yourself clean.”\n",
"Other symptoms may be reported and are claimed to be related to the cause of the odor, such as malfunction of the anal sphincter, a skin disease, \"diseased womb\", stomach problems or other unknown organic disease. Excessive washing in ORS has been reported to cause the development of eczema.\n",
"Smell disorders can result in the inability to detect environmental dangers such as gas leaks, toxins, or smoke. In addition to safety, nutritional and eating habits can also be affected. There is a loss of appetite because of unpleasant flavor and fear of failing to recognize and consuming spoiled food. A decreased or distorted sense of smell therefore results in a decreased quality of life. Distortions are believed to have a greater negative impact on people than the complete loss of smell because they are constantly reminded of the disorder and the distortions have a greater effect on eating habits.\n",
"Scientists have long thought that smelling one's own breath odor is often difficult due to acclimatization, although many people with bad breath are able to detect it in others. Research has suggested that self-evaluation of halitosis is not easy because of preconceived notions of how bad we think it should be. Some people assume that they have bad breath because of bad taste (metallic, sour, fecal, etc.), however bad taste is considered a poor indicator.\n",
"Although all individuals with ORS believe they have an odor, in some cases the individual reports they cannot perceive the odor themselves. In the latter cases, the belief arises via misinterpretation of the behavior of others or with the rationale that a disorder of smell which prevents self detection of the odor (i.e. anosmia) exists. In the cases where the non-existent odor can be detected, this is usually considered as phantosmia (olfactory hallucination). Olfactory hallucination can be considered the result of the belief in an odor delusion, or the belief a result of the olfactory hallucination. In one review, the individual with ORS was unreservedly convinced that he or she could detect the odor themselves in 22% of cases, whilst in 19% there was occasional or intermittent detection and in 59% lack of self-detection was present.\n"
] |
My great uncle enrolled in the Charlemagne Waffen SS Division, is there online ressources I could check to find out what happened to him ?
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Hi, hopefully someone can drop by to help with something more specific, but you might find these resources helpful : the sub has a wiki for finding military records [here](_URL_0_). You might also try x-posting to /r/genealogy for more tips.
|
[
"Gottlob Christian Berger (16 July 1896 – 5 January 1975) was a senior German Nazi official who held the rank of \"SS-Obergruppenführer und General der Waffen-SS\" (lieutenant general), and was the chief of the SS Main Office responsible for \"Schutzstaffel\" (SS) recruiting during World War II. Following the war, he was convicted as a war criminal, spending a total of six-and-a-half years in prison. Serving in the German Army during World War I, he was wounded four times and awarded the Iron Cross First Class. Immediately after the war, he was a leader of the \"Einwohnerwehr\" militia in his native North Württemberg. He joined the Nazi Party in 1922, but lost interest in right-wing politics during the 1920s, training and working as a physical education teacher.\n",
"Her book traces the lives of the three Himmler brothers (the eldest was Gebhard Himmler), the sons of a respected secondary school headmaster in Munich. Gebhard served in the German Army in World War I, but Heinrich, who at 18 was still an officer cadet when the war ended, was too young to see frontline service. Katrin Himmler speculates that it was frustration at this and envy of his brother that led Heinrich to join the extreme right-wing Freikorps in 1919. In the Freikorps he served under Ernst Röhm and was thus led into the Nazi Party.\n",
"Gustav Krukenberg (8 March 1888 – 23 October 1980) was a high-ranking member of the Waffen-SS and commander of the SS Charlemagne Division and the remains of the SS Division Nordland during the Battle of Berlin in April 1945. After Krukenberg surrendered to Soviet Red Army troops, he was tried, convicted and sentenced to prison by a Soviet court. He was released from prison after serving 11 years and died on 23 October 1980 in Germany.\n",
"Richard Landwehr is the author of numerous books about the Waffen-SS, its non-German volunteers in particular, providing revisionist and apologetic accounts of these men and their battles. He has been producing the magazine \"Siegrunen\" on the same topic for over 30 years. Landwehr has written for the Journal for Historical Review (JHR) which is published by the Institute for Historical Review, an American Holocaust denial organization.\n",
"Desiderius Hampel (20 January 1895 – 11 January 1981) was a \"SS-Brigadeführer und Generalmajor der Waffen-SS\" during World War II who commanded the 13th \"Waffen\" Mountain Division of the SS \"Handschar\" (1st Croatian) and was possibly awarded the Knight's Cross of the Iron Cross (\"Ritterkreuz\"), the highest award in the military and paramilitary forces of Nazi Germany during World War II. After the war the Yugoslavian government asked for his extradition to charge him with war crimes, but he managed to escape from a British internment camp.\n",
"Schönhuber attended Gymnasium in Munich and gained his Abitur in 1942. As a nineteen-year-old he was a member of the Hitler Youth and a member of the Nazi Party. He voluntarily joined the Waffen-SS and was deployed at the front. He has claimed to have been an instructor and translator for the French \"Charlemagne\" brigade. As a SS-\"Unterscharführer\", he gained a second class Iron Cross.\n",
"Otto Weidinger (27 May 1914 – 10 January 1990) was a member of the Waffen-SS in Nazi Germany and a regimental commander in the SS Division Das Reich during World War II. In this capacity, he was involved in the Oradour massacre in France in June 1944. He was the author of a revisionist account of the division's history, produced under the auspices of HIAG, a Waffen-SS lobby group in post-war West Germany.\n"
] |
Feyman diagrams and gauge bosons?
|
Yes, the axis represents time. Feynman diagrams are not a literal depiction of what’s happening, so the fact that the positron arrow looks like it’s pointing backward in time doesn’t mean that any particle is literally moving backward in time.
The gluons are the gauge bosons of the strong force, and the photon is the gauge boson of the EM force. Beta decay is a weak process, so the virtual particle here is one of the weak bosons (W^(+/-) and Z).
|
[
"Gauge theories are important as the successful field theories explaining the dynamics of elementary particles. Quantum electrodynamics is an abelian gauge theory with the symmetry group U(1) and has one gauge field, the electromagnetic four-potential, with the photon being the gauge boson. The Standard Model is a non-abelian gauge theory with the symmetry group U(1) × SU(2) × SU(3) and has a total of twelve gauge bosons: the photon, three weak bosons and eight gluons.\n",
"The term bolometer is also used in particle physics to designate an unconventional particle detector. They use the same principle described above. The bolometers are sensitive not only to light but to every form of energy.\n",
"The use of spectrophotometers spans various scientific fields, such as physics, materials science, chemistry, biochemistry, Chemical Engineering, and molecular biology. They are widely used in many industries including semiconductors, laser and optical manufacturing, printing and forensic examination, as well in laboratories for the study of chemical substances. Spectrophotometry is often used in measurements of enzyme activities, determinations of protein concentrations, determinations of enzymatic kinetic constants, and measurements of ligand binding reactions. Ultimately, a spectrophotometer is able to determine, depending on the control or calibration, what substances are present in a target and exactly how much through calculations of observed wavelengths.\n",
"A gauge theory like electromagnetism is defined by a gauge field, which associates a group element to each path in space time. For infinitesimal paths, the group element is close to the identity, while for longer paths the group element is the successive product of the infinitesimal group elements along the way.\n",
"In particle physics, a gauge boson is a force carrier, a bosonic particle that carries any of the fundamental interactions of nature, commonly called forces. Elementary particles, whose interactions are described by a gauge theory, interact with each other by the exchange of gauge bosons—usually as virtual particles.\n",
"In mathematics, the Weierstrass M-test is a test for determining whether an infinite series of functions converges uniformly and absolutely. It applies to series whose terms are functions with real or complex values, and is analogous to the comparison test for determining the convergence of series of real or complex numbers.\n",
"This article describes the mathematics of the Standard Model of particle physics, a gauge quantum field theory containing the internal symmetries of the unitary product group . The theory is commonly viewed as containing the fundamental set of particles – the leptons, quarks, gauge bosons and the Higgs particle.\n"
] |
Why is it that high current is dangerous but high voltage (to a certain limit) is not as dangerous?
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We can be killed by 0.01A across the heart. An amp is quite a lot really. When you are electrocuted, what kills you is amperage across the heart. Enough amperage and it interferes with the heart's natural electrical signals, stopping it.
Voltage and amperage are two different aspects of the same thing. Think of it in terms of water flow, where voltage is water pressure, and amperage is the actual amount of flowing water. A squirt gun may squirt water faster than a river can flow, but a river obviously has a lot more water overall.
Voltage and Amperage have a linear relationship with Resistance. You feed something a certain number of amps, and the resistance will determine the voltage that makes it through. Feed it a certain number of volts and the resistance will determine the amount of amps that make it through. Resistance, in our water analogy is like the nozzle to a hose, where you can have a wide nozzle that gives out a lot of water slowly (low resistance = low voltage high amperage), or you can have a small nozzle that shoots a small amount of water out really quickly (high resistance = high voltage, low amperage)
So anyway, if a shock travels through your heart, and the voltage is high enough to overcome the resistance, and the amperage across the heart is over 10mA, it can interrupt your heart's electrical signals, causing cardiac arrest.
Sorry if I explained this like an ELI5, but if you want further reading try [here](_URL_0_) and [here](_URL_1_).
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[
"A high voltage is not necessarily dangerous if it cannot deliver substantial current. The common static electric sparks seen under low-humidity conditions always involve voltage well above 700 V. For example, sparks to car doors in winter can involve voltages as high as 20,000 V. Also, physics demonstration devices such as Van de Graaff generators and Wimshurst machines can produce voltages approaching one million volts, yet at worst they deliver a brief sting. That is because the number of electrons involved is not high. These devices have a limited amount of stored energy, so the average current produced is low and usually for a short time, with impulses peaking in the 1 A range for a nanosecond. During the discharge, these machines apply high voltage to the body for only a millionth of a second or less. So a low current is applied for a very short time, and the number of electrons involved is very small.\n",
"The current may, if it is high enough and is delivered at sufficient voltage, cause tissue damage or fibrillation which can cause cardiac arrest; of AC (rms, 60 Hz) or of DC at high voltage can cause fibrillation. A sustained electric shock from AC at 120 V, 60 Hz is an especially dangerous source of ventricular fibrillation because it usually exceeds the let-go threshold, while not delivering enough initial energy to propel the person away from the source. However, the potential seriousness of the shock depends on paths through the body that the currents take. If the voltage is less than 200 V, then the human skin, more precisely the stratum corneum, is the main contributor to the impedance of the body in the case of a macroshock—the passing of current between two contact points on the skin. The characteristics of the skin are non-linear however. If the voltage is above 450–600 V, then dielectric breakdown of the skin occurs. The protection offered by the skin is lowered by perspiration, and this is accelerated if electricity causes muscles to contract above the let-go threshold for a sustained period of time.\n",
"In electrical power systems \"low voltage\" most commonly refers to the mains voltages as used by domestic and light industrial and commercial consumers. \"Low voltage\" in this context still presents a risk of electric shock, but only a minor risk of electric arcs through the air.\n",
"Voltages over approximately 50 volts can usually cause dangerous amounts of current to flow through a human being who touches two points of a circuit—so safety standards, in general, are more restrictive around such circuits. The definition of \"extrahigh voltage\" (EHV) again depends on context. In electric power transmission engineering, EHV is classified as voltages in the range of 345,000 - 765,000 volts. In electronics systems, a power supply that provides greater than 275,000 volts is called an \"EHV Power Supply\", and is often used in experiments in physics.\n",
"BULLET::::- Current. The higher the current, the more likely it is lethal. Since current is proportional to voltage when resistance is fixed (ohm's law), high voltage is an indirect risk for producing higher currents.\n",
"Electricity is hazardous: an electric shock from a current as low as 35 milliamps is sufficient to cause fibrillation of the heart in vulnerable individuals. Even a healthy individual is at risk of falling from a high structure due to loss of muscle control. Higher currents can cause respiratory failure and result in extensive and life-threatening burns. The first recorded human fatality occurred in 1879 when a stage carpenter in Lyon, France touched a 250 volt wire. The lack of any visible sign that a conductor is energised, even at high voltages, makes electricity a particular hazard.\n",
"The health hazard of an electric current flowing through the body depends on the amount of current and the length of time for which it flows, not merely on the voltage. However, a high voltage is required to produce a high current through the body. This is due to the relatively high resistance of skin when dry, requiring a high voltage to pass through. The severity of a shock also depends on whether the path of the current includes a vital organ. \n"
] |
Why do we not perceive the expansion of the universe?
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We're not growing larger. Space inside our bodies is expanding, yes, but our cells aren't "anchored" to this space. They're anchored to each other. If you spread your arms wide, your fingertips are continuously moving towards each other at the same rate that new space is appearing within you.
Imagine this: Take two lego bricks, put them together and lay them on a rubber surface. Then stretch the surface. The lego bricks don't separate, because they're joined together tightly and the rubber surface isn't pulling on them enough to separate them.
That is why you're not getting bigger, your journey to work isn't getting longer, and you don't have more stairs to climb every day: all those things are bound together like your lego bricks. But when you consider two galaxies that are far apart and not really bound together in any way, that is like two separate lego bricks on your rubber mat. The distance between these grows larger as you stretch the mat.
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[
"The expansion of the universe reaches an infinite degree in finite time, causing expansion to accelerate without bounds. This acceleration necessarily passes the speed of light (since it involves expansion of the universe itself, not particles moving within it), causing more and more objects to leave our observable universe faster than its expansion, as light and information emitted from distant stars and other cosmic sources cannot \"catch up\" with the expansion. As the observable universe expands, objects will be unable to interact with each other via fundamental forces, and eventually the expansion will prevent any action of forces between any particles, even within atoms, \"ripping apart\" the universe.\n",
"The expansion of the universe is the increase of the distance between two distant parts of the universe with time. It is an intrinsic expansion whereby \"the scale of space itself changes\". The universe does not expand \"into\" anything and does not require space to exist \"outside\" it. Technically, neither space nor objects in space move. Instead it is the metric governing the size and geometry of spacetime itself that changes in scale. Although light and objects within spacetime cannot travel faster than the speed of light, this limitation does not restrict the metric itself. To an observer it appears that space is expanding and all but the nearest galaxies are receding into the distance.\n",
"However, because the expansion of the universe is accelerating, it is projected that most galaxies will eventually cross a type of cosmological event horizon where any light they emit past that point will never be able to reach us at any time in the infinite future, because the light never reaches a point where its \"peculiar velocity\" towards us exceeds the expansion velocity away from us (these two notions of velocity are also discussed in Comoving and proper distances#Uses of the proper distance). The current distance to this cosmological event horizon is about 16 billion light-years, meaning that a signal from an event happening at present would eventually be able to reach us in the future if the event was less than 16 billion light-years away, but the signal would never reach us if the event was more than 16 billion light-years away.\n",
"The expansion of space is sometimes described as a force which acts to push objects apart. Though this is an accurate description of the effect of the cosmological constant, it is not an accurate picture of the phenomenon of expansion in general. For much of the universe's history the expansion has been due mainly to inertia. The matter in the very early universe was flying apart for unknown reasons (most likely as a result of cosmic inflation) and has simply continued to do so, though at an ever-decreasing rate due to the attractive effect of gravity.\n",
"At a fundamental level, the expansion of the universe is a property of spatial measurement on the largest measurable scales of our universe. The distances between cosmologically relevant points increases as time passes leading to observable effects outlined below. This feature of the universe can be characterized by a single parameter that is called the scale factor which is a function of time and a single value for all of space at any instant (if the scale factor were a function of space, this would violate the cosmological principle). By convention, the scale factor is set to be unity at the present time and, because the universe is expanding, is smaller in the past and larger in the future. Extrapolating back in time with certain cosmological models will yield a moment when the scale factor was zero; our current understanding of cosmology sets this time at 13.799 ± 0.021 billion years ago. If the universe continues to expand forever, the scale factor will approach infinity in the future. In principle, there is no reason that the expansion of the universe must be monotonic and there are models where at some time in the future the scale factor decreases with an attendant contraction of space rather than an expansion.\n",
"Whether our universe is ever-expanding depends on the amount and properties of matter, but there is too little visible matter around us to explain the behavior we can see—over 90% of the universe consists of the missing mass or dark matter, which Krauss termed \"the fifth essence.\" In this book Krauss demonstrates how the dark matter problem is now connected with two widely discussed areas in the modern cosmology: the ultimate fate of the universe and the cosmological constant. He also discusses an antigravity force that may explain recent observations of a permanently expanding universe.\n",
"An expanding universe generally has a cosmological horizon, which, by analogy with the more familiar horizon caused by the curvature of Earth's surface, marks the boundary of the part of the Universe that an observer can see. Light (or other radiation) emitted by objects beyond the cosmological horizon in an accelerating universe never reaches the observer, because the space in between the observer and the object is expanding too rapidly.\n"
] |
does a house ever finish settling?
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Short answer: no
Long answer: I believe it is never settled because it's the materials of the house expanding due to the heat of the day and then contracting when it's cooling down at night
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[
"The old house, dating from the Revolutionary War-era, turns out to be structurally unsound and has to be torn down before the previous owner's $6,000 mortgage is paid off. The Blandingses hire architect Henry Simms (Reginald Denny) to design and supervise the construction of the new home for $18,000 ($187,000 in 2017 dollars). From the original purchase to the new house's completion, a long litany of unforeseen troubles and setbacks, including digging a well, beset the hapless Blandingses and delay their moving-in date. On top of all this, at work Jim is assigned the task of coming up with a slogan for \"WHAM\" Brand Ham, an advertising account that has destroyed the careers of previous account executives assigned to it. Jim also suspects that Muriel is cheating on him with Bill Cole after Bill slept at the Blandingses' alone in the house with Muriel one night due to a violent thunderstorm.\n",
"The house was empty for six years, while the developers sold off various parcels of land, particularly the orchards and paddocks. However, before the final carve-up of the estate could be undertaken, the leader of the consortium, Sir Thomas Bent, died and the property was put on the market in 1910.\n",
"The maker of the settle is unknown; it is believed to be either Harland and Fisher, who had made earlier pieces of furniture for Burges, or John Walden, who made the guest bedroom furniture for the Tower House.\n",
"On 27 September 2005, the London Borough of Southwark decided that rather than spend £350 million updating the estate to basic living standards, it would order its demolition and replace the dwellings with modern houses controlled by a housing association. The plan involves increasing the density of housing from the current 2,700 units to 4,900. 2,288 units would remain social housing and the remainder would be for sale. The sale of these units is planned to fund the whole scheme.\n",
"problems of the surviving Master's House mean that it's on Historic England's Heritage at Risk register as 'very bad'. In 2018 it was announced that after laying unused and covered up for \"almost four decades\" £530,000 would be allocated to the site to use it for supported housing, preserving the older buildings in their current condition as best as possible.\n",
"Some of the redeveloped houses, built in 1986, were judged to be at risk of subsidence in 2009. The tenants were evacuated and the buildings were finally demolished in 2015 after standing empty for 6 years and becoming an eyesore. The only option left to the Council was to demolish the homes for £230,000 and then to make a park.\n",
"In 1998 the house was bought for £360,000 by a couple who intended to restore it with friends. Part-restoration of some areas was completed in 2002. After having parted ways, the remaining owner, Jeannie Wilkins, unable to afford further restoration works and upkeep, placed the 17-bedroom house, with of land, up for sale with a price of £1,695,000 however it is estimated it would take at least £500,000 to make it habitable.\n"
] |
in the shell sort algorithm, why are the numbers 1,4,10,23,57,132,301,701,1750 used? they seem to be ambiguous and are really confusing me...
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Shell sort partitions the data. The exact partition is not that important, but the properties of the partition (i.e. "gap sequence") do affect the runtime.
"Gonnet and Baeza-Yates observed that Shellsort makes the fewest comparisons on average when the ratios of successive gaps are roughly equal to 2.2."
You need to have some numbers to do the partition, so those numbers are one set that is known to work well, but you can change them and it will still work.
_URL_0_
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[
"Shellsort is a generalization of insertion sort that allows the exchange of items that are far apart. The idea is to arrange the list of elements so that, starting anywhere, considering every \"h\"th element gives a sorted list. Such a list is said to be \"h\"-sorted. Equivalently, it can be thought of as \"h\" interleaved lists, each individually sorted. Beginning with large values of \"h\", this rearrangement allows elements to move long distances in the original list, reducing large amounts of disorder quickly, and leaving less work for smaller \"h\"-sort steps to do. If the list is then \"k-sorted\" for some smaller integer \"k\", then the list remains \"h\"-sorted. Following this idea for a decreasing sequence of \"h\" values ending in 1 is guaranteed to leave a sorted list in the end.\n",
"Shellsort, also known as Shell sort or Shell's method, is an in-place comparison sort. It can be seen as either a generalization of sorting by exchange (bubble sort) or sorting by insertion (insertion sort). The method starts by sorting pairs of elements far apart from each other, then progressively reducing the gap between elements to be compared. Starting with far apart elements, it can move some out-of-place elements into position faster than a simple nearest neighbor exchange. Donald Shell published the first version of this sort in 1959. The running time of Shellsort is heavily dependent on the gap sequence it uses. For many practical variants, determining their time complexity remains an open problem.\n",
"\"Shellsort\" was invented by Donald Shell in 1959. It improves upon insertion sort by moving out of order elements more than one position at a time. The concept behind Shellsort is that insertion sort performs in time, where k is the greatest distance between two out-of-place elements. This means that generally, they perform in \"O\"(\"n\"), but for data that is mostly sorted, with only a few elements out of place, they perform faster. So, by first sorting elements far away, and progressively shrinking the gap between the elements to sort, the final sort computes much faster. One implementation can be described as arranging the data sequence in a two-dimensional array and then sorting the columns of the array using insertion sort.\n",
"Shellsort, discovered by Donald Shell in 1959, is a comparison sort which divides a list to be sorted into sublists and sorts them separately. The sorted sublists are then merged, reconstituting a partially-sorted list. This process repeats a number of times (the number of passes). The difficulty of analyzing the complexity of the sorting process is that it depends on the number formula_2 of keys to be sorted, on the number formula_89 of passes and the increments governing the scattering in each pass; the sublist is the list of keys which are the increment parameter apart. Although this sorting method inspired a large number of papers, only the worst case was established. For the average running time, only the best case for a two-pass Shellsort and an upper bound of formula_90 for a particular increment sequence for three-pass Shellsort were established. A general lower bound on an average formula_89-pass Shellsort was given which was the first advance in this problem in four decades. In every pass, the comparison sort moves a key to another place a certain distance (a path length). All these path lengths are logarithmically coded for length in the correct order (of passes and keys). This allows the reconstruction of the unsorted list from the sorted list. If the unsorted list is incompressible (or nearly so), since the sorted list has near-zero Kolmogorov complexity (and the path lengths together give a certain code length) the sum must be at least as large as the Kolmogorov complexity of the original list. The sum of the path lengths corresponds to the running time, and the running time is lower-bounded in this argument by formula_92. This was improved in to a lower bound of \n",
"BULLET::::- \"The value of a row\", if each entry is considered a decimal place (and numbers larger than 9 carried over accordingly), is a power of 11 ( , for row ). Thus, in row 2, becomes 11, while in row five becomes (after carrying) 161,051, which is 11. This property is explained by setting in the binomial expansion of , and adjusting values to the decimal system. But can be chosen to allow rows to represent values in \"any\" base.\n",
"255 is a special number in some tasks having to do with computing. This is the maximum value representable by an eight-digit binary number, and therefore the maximum representable by an unsigned 8-bit byte (the most common size of byte, also called an octet), the smallest common variable size used in high level programming languages (bit being smaller, but rarely used for value storage). The range is 0 to 255, which is 256 total values.\n",
"The meaning of \"small enough\" depends on the size of the type that is used as the hashed value. For example, in Java, the hash code is a 32-bit integer. Thus the 32-bit integer codice_1 and 32-bit floating-point codice_2 objects can simply use the value directly; whereas the 64-bit integer codice_3 and 64-bit floating-point codice_4 cannot use this method.\n"
] |
Why are British colonies in the Caribbean so homophobic?
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I feel this is a loaded question as Montserrat, the Cayman Islands, the British Virgin Islands and the Turks and Caicos Islands all consider homosexual activity perfectly legal. So perhaps the question should more focus on why Jamaica itself is so homophobic as being a British Colony past or present seems to not be a variable in the conversation. From what I can briefly turn up, it seems the compounded problem of poverty, lack of education, disease (HIV) and masculinity issues all tied in with religion.
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[
"All other colonials not already resident in the UK or the Crown Dependencies lost the rights of abode and work in the UK when the Act went into force. This caused anger in the affected colonies as the Act, which resulted from the desire to prevent ethnic-Chinese people in Hong Kong with UK and Colonies Citizenship from migrating to the UK prior to the planned 1997 hand-over of the colony to China, was seen as racist, especially as those colonials in affected colonies who possessed a qualifying connection to the UK sufficient to retain either British citizenship or a \"right to remain\" (in the UK) notification in their BDTC passports were usually white. The former colonials also objected to being described as \"dependent\", especially in Bermuda, which had been self-reliant virtually since 1612, and largely self-governed since 1620. This resentment was exacerbated when full British citizenship was returned to Gibraltarians, ensuring that those from territories perceived as having negligible non-white populations retained free movement into the UK, with rights of abode and work, as did many of the whites in the remaining \"coloured\" colonies. Most non-whites in those remaining territories, by contrast, could only enter the UK as short-term visitors (with a date stamped in their passports by which they must exit) or with difficult-to-obtain entry clearances.\n",
"Islands in the Commonwealth Caribbean adopted British buggery laws; however these laws were not as strictly regulated in the Caribbean as in the United Kingdom up until the Victorian era. Prior to this era, recounts were made of the island's British occupants engaging in sodomy, which may correlate with the fact that the first colonists were mostly men. The slave communities in Jamaica and the rest of the British Caribbean were made up of men and women from West Africa, the men being more sought after by slave owners.\n",
"Barbados along with many other Caribbean nations was once part of the British Empire, between 1627 and 1966 the Island was under British rule, and it retained more of a 'British' identity compared to the other surrounding nations. Barbados was often referred to as \"Little England\" by its inhabitants as well as neighbours. The result of this close bond between the two nations is that the UK proves the most popular destination for Barbadian emigrants who then find it much easier to settle into society than many other English and non-English speaking immigrant groups. Leading on from British colonial rule in Barbados, one of the island nation's most popular pastimes is playing cricket (a sport introduced and still played by the British). The culture of the Barbadian community in the UK is also heavily influenced by West African cultures, due to traditions dating back to the slave trade generation.\n",
"In the USA, Canada, and the UK, the non-Anglophone Caribbean community is mixed with many from the Anglophone Caribbean community. Some cases of segregation have arisen among West Indian people, however, which causes a commonly found rivalry between people from the larger island of Jamaica and those from the smaller \"Smallie\" islands of the Southern Caribbean. From the 1960s to the 1980s, many Jamaicans would not associate with someone from Trinidad/Barbados/Grenada, and vice versa. Tensions between the regions originate from the days of slavery, as both regions blame each other for \"selling them out\" to Europeans. During the 1960s-1980s, this racial tension reached a high point as many Caribbean people were discouraged from intermingling with those from other nations. They were even encouraged to marry only their \"own people\", that is, Jamaican man with a Jamaican woman, Trinidadian man with a Trinidadian woman and so forth.\n",
"The Caribbean island of Montserrat has experienced British rule for centuries. British control was established in 1632 and to this day it remains an overseas territory of the United Kingdom. This in itself makes it easy for the overseas British citizens to migrate to the UK with few problems. \n",
"Due to prolonged colonial contact with Portugal, the Netherlands and Britain, Sri Lanka has had a long history of intermarriage between locals and colonists. Originally these people were known as Mestiços, literally \"mixed people\" in Portuguese; today they are collectively classified as Burghers. The Sri Lankan Civil War prompted numerous Burghers to flee the island. Most of them settled in Europe, the Americas, Australia and New Zealand.\n",
"Homophobia in Jamaica is bolstered by the contemporary association of homosexuality with colonization, and by extension, of homophobia with anti-colonialism. Scholar Wayne Marshall describes that, in Jamaica, acts of homosexuality are believed to be “decadent products of the West” and “are thus to be resisted alongside other forms of colonization, cultural or political.” This sentiment is most strongly demonstrated in Jamaican dancehall hit “Dem Bow” by Shabba Ranks, in which homosexuality is violently condemned alongside a call for the “freedom for Black people.” This is despite extensive evidence of normalized queerness in pre-colonial Africa, in addition to evidence that colonialism actually introduced homophobia to African societies.\n"
] |
Why is angular momentum one-sided even if a spinning object is symmetrical?
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It is convention only, to allow scientists to talk to each other without having to describe which coordinate system they are using every time. Let me explain.
The direction of the angular momentum of an object doesn't mean anything by itself. What matters is that when object A with angular momentum interacts with object B with angular momentum, that the angular momentum is conserved. Then, you can know how the objects will be acting afterwards. The reason we use these conventions, is that you don't always want to start back at the very beginning. Say you know how a certain experiment will end up, and then you want to move on. You can start with "this experiment will lead to an angular momentum in the +z direction" and move on, without having to describe what that means.
If instead we used a left hand rule, but used it consistently throughout all calculations, everything would work out just the same.
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[
"Like linear momentum, angular momentum is vector quantity, and its conservation implies that the direction of the spin axis tends to remain unchanged. For this reason, the spinning top remains upright whereas a stationary one falls over immediately.\n",
"If two or more axes have the same direction, the axis with higher symmetry is shown. Higher symmetry means that the axis generates a pattern with more points. For example, rotation axes 3, 4, 5, 6, 7, 8 generate 3-, 4-, 5-, 6-, 7-, 8-point patterns, respectively. Improper rotation axes , , , , , generate 6-, 4-, 10-, 6-, 14-, 8-point patterns, respectively. If a rotation and a rotoinversion axis generate the same number of points, the rotation axis should be chosen. For example, the combination is equivalent to . Since generates 6 points, and 3 generates only 3, should be written instead of (not , because already contains the mirror plane \"m\"). Analogously, in the case when both 3 and axes are present, should be written. However we write , not , because both 4 and generate four points. In the case of the combination, where 2, 3, 6, , and axes are present, axes , , and 6 all generate 6-point patterns, but the latter should be used because it is a rotation axis — the symbol will be .\n",
"We have supposed that the rigid body rotates around an arbitrary point. We should prove that the spin angular velocity previously defined is independent of the choice of origin, which means that the spin angular velocity is an intrinsic property of the spinning rigid body. (Note the marked contrast of this with the \"orbital\" angular velocity of a point particle, which certainly \"does\" depend on the choice of origin.)\n",
"The angular velocity vector also points along the axis of rotation in the same way as the angular displacements it causes. If a disk spins counterclockwise as seen from above, its angular velocity vector points upwards. Similarly, the angular acceleration vector points along the axis of rotation in the same direction that the angular velocity would point if the angular acceleration were maintained for a long time.\n",
"A twist represents the velocity of a rigid body as an angular velocity around an axis and a linear velocity along this axis. All points in the body have the same component of the velocity along the axis, however the greater the distance from the axis the greater the velocity in the plane perpendicular to this axis. Thus, the helicoidal field formed by the velocity vectors in a moving rigid body flattens out the further the points are radially from the twist axis.\n",
"In classical mechanics, the angular momentum of a particle possesses not only a magnitude (how fast the body is rotating), but also a direction (either up or down on the axis of rotation of the particle). Quantum mechanical spin also contains information about direction, but in a more subtle form. Quantum mechanics states that the component of angular momentum measured along any direction can only take on the values \n",
"The angular momentum of a rotating body is proportional to its mass and to how rapidly it is turning. In addition, the angular momentum depends on how the mass is distributed relative to the axis of rotation: the further away the mass is located from the axis of rotation, the greater the angular momentum. A flat disk such as a record turntable has less angular momentum than a hollow cylinder of the same mass and velocity of rotation.\n"
] |
why does scanning take so long if photocopying or taking a photo of something is so quick?
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Because you have a cheap scanner. Cheap scanners are slow. Expensive high end scanners are very fast.
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[
"The scanning techniques are generally slower in acquiring images, due to the scanning process. As a result, efforts are being made to greatly improve the scanning rate. Like all scanning techniques, the embedding of spatial information into a time sequence opens the door to uncertainties in metrology, say of lateral spacings and angles, which arise due to time-domain effects like specimen drift, feedback loop oscillation, and mechanical vibration.\n",
"Today, it is possible to scan documents of different dimensions and formats in the same flow, scan colour documents, sort them physically and read data from them using OCR and barcode technologies during the scanning process. Processing speed has also significantly increased.\n",
"If this search takes more than a second or so, a progress dialog shows the scanning process taking place. This dialog can easily be confused with an Explorer copy operation; however, no files are being copied or moved.\n",
"conducted at a higher rate (700 words per minute and above) than normal reading for comprehension (around 200–230 wpm), and results in lower comprehension rates, especially with information-rich reading material. Scanning is the process where one actively looks for information using a mind-map (organizing information in a visually hierarchical manner that showcases the interrelatedness of the information for better retrievability) formed from skimming. These techniques are used by meta-guiding your eyes. Scanning includes the main point as well as headings and important information.\n",
"Whilst scanning with document cameras may have a quick reaction time, large amounts of batch scanning of even, unstapled documents is more efficient with an ADF scanner. There are challenges which face this kind of technology regarding external factors (such as lighting) which may have influence on the scan results. The way in which these issues are resolved strongly depends on the sophistication of the product and how it deals with these issues.\n",
"Scanning backs operate more like an image scanner for paper: they have a linear array of sensors that is moved across the image area to scan the image one row of pixels at a time. Scanning backs are primarily used in large format view cameras.\n",
"The scanning speed of an AFM is also a limitation. Traditionally, an AFM cannot scan images as fast as an SEM, requiring several minutes for a typical scan, while an SEM is capable of scanning at near real-time, although at relatively low quality. The relatively slow rate of scanning during AFM imaging often leads to thermal drift in the image making the AFM less suited for measuring accurate distances between topographical features on the image. However, several fast-acting designs were suggested to increase microscope scanning productivity including what is being termed videoAFM (reasonable quality images are being obtained with videoAFM at video rate: faster than the average SEM). To eliminate image distortions induced by thermal drift, several methods have been introduced.\n"
] |
why do heroin users have to switch veins? what does the heroin do to “kill” the vein?
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It's not the heroin. It's poking the same spot with a needle over and over again without giving it enough time to heal. It can get more complicated where if you *do* give it time to heal after you've abused it too much it will develop scar tissue which makes it harder to inject there.
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[
"After injecting herself with heroin using a syringe, the user will extract approximately 5 ccs of blood from her vein, which another user will inject into her vein. It is unclear if there is enough heroin in the small volume of injected blood to get high or if the high that many users claim is a result of traces of the heroin that had been injected by the user, or if the high is simply the result of the placebo effect. Sharing blood in this manner carries a very high risk of transmitting viruses such as hepatitis and HIV, which are prevalent among injection drug users in East Africa.\n",
"Heroin is commonly cut with quinine, caffeine, dimethocaine, procaine, lactose, inositol, dextrose, mannitol, and starch. Other opioids are sometimes sold as heroin or cut with heroin. Fentanyl sold as or laced into heroin has made the news in the past due to the numerous fatalities it causes when it appears on the market. Recently, Fentanyl and close analogues have been produced in pure powder form for very cheap. Dealers may cut with or sell heroin with Fentanyl due to the street cost of Fentanyl versus the cost of heroin. The potency of such mixtures (especially if made carelessly) can be far above that of pure heroin, and users frequently overdose due to this.\n",
"This method of intake significantly decreases or eliminates certain risks of heroin use, such as the transmission of HIV, hepatitis, and other diseases through needle sharing, the introduction of skin bacteria to the blood stream due to non-sterile injection, and the stress that injection puts on veins cannot occur. Additionally, a small puff can be inhaled as a method of gauging the strength of the heroin. This may protect users from overdosing. Finally, the lungs can act to filter out adulterants that otherwise would pass directly into the bloodstream. One of the most common of these adulterants, talc, has an apparently greater potential to damage the lungs (as well as other organs, such as the kidneys) when present in the bloodstream, than when inhaled.\n",
"Another popular route to intake heroin is insufflation (snorting), where a user crushes the heroin into a fine powder and then gently inhales it (sometimes with a straw or a rolled-up banknote, as with cocaine) into the nose, where heroin is absorbed through the soft tissue in the mucous membrane of the sinus cavity and straight into the bloodstream. This method of administration redirects first-pass metabolism, with a quicker onset and higher bioavailability than oral administration, though the duration of action is shortened. This method is sometimes preferred by users who do not want to prepare and administer heroin for injection or smoking, but still experience a fast onset. Snorting heroin becomes an often unwanted route, once a user begins to inject the drug. The user may still get high on the drug from snorting, and experience a nod, but will not get a rush. A \"rush\" is caused by a large amount of heroin entering the body at once. When the drug is taken in through the nose, the user does not get the rush because the drug is absorbed slowly rather than instantly.\n",
"Ingestion does not produce a rush as forerunner to the high experienced with the use of heroin, which is most pronounced with intravenous use. While the onset of the rush induced by injection can occur in as little as a few seconds, the oral route of administration requires approximately half an hour before the high sets in. Thus, with both higher the dosage of heroin used and faster the route of administration used, the higher potential risk for psychological addiction.\n",
"Injection, also known as \"slamming\", \"banging\", \"shooting up\", \"digging\" or \"mainlining\", is a popular method which carries relatively greater risks than other methods of administration. Heroin base (commonly found in Europe), when prepared for injection, will only dissolve in water when mixed with an acid (most commonly citric acid powder or lemon juice) and heated. Heroin in the east-coast United States is most commonly found in the hydrochloride salt form, requiring just water (and no heat) to dissolve. Users tend to initially inject in the easily accessible arm veins, but as these veins collapse over time, users resort to more dangerous areas of the body, such as the femoral vein in the groin. Users who have used this route of administration often develop a deep vein thrombosis. Intravenous users can use a various single dose range using a hypodermic needle. The dose of heroin used for recreational purposes is dependent on the frequency and level of use: thus a first-time user may use between 5 and 20 mg, while an established addict may require several hundred mg per day. As with the injection of any drug, if a group of users share a common needle without sterilization procedures, blood-borne diseases, such as HIV/AIDS or hepatitis, can be transmitted.\n",
"Smaller veins may collapse as a consequence of too much suction being used when pulling back against the plunger of the syringe to check that the needle is in the vein. This will pull the sides of the vein together and, especially if they are inflamed, they may stick together causing the vein to block. Removing the needle too quickly after injecting can have a similar effect.\n"
] |
how are things n% water?
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Heat it until the water evaporates, check its mass before and after and calculate the percentage
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[
"Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water. The quantity “1 ppm” can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution. When working with aqueous solutions, it is common to assume that the density of water is 1.00 g/mL. Therefore, it is common to equate 1 kilogram of water with 1 L of water. Consequently, 1 ppm corresponds to 1 mg/L and 1 ppb corresponds to 1 μg/L.\n",
"A study published in \"The Spokesman-Review\" on May 6, 1909, by City bacteriologist, Frank Rose found only seven or eight germs per cubic centimeter of water. As a standard, \"water that contains 100 germs per cubic centimeter is considered comparatively pure\".\n",
"Water () is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the \"universal solvent\" and the \"solvent of life\". It is the most abundant substance on Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe.\n",
"BULLET::::- virtual water - the volume of water required to produce a commodity or service. First coined by Professor J.A. Allan of the University of London in the early 1990s, though this is now more widely known as cf. embedded (embodied) water.\n",
"Water is a chemical substance that is composed of hydrogen and oxygen and is vital for all known forms of life. In typical usage, \"water\" refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor, or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large bodies of water, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds, and precipitation. Oceans hold 97% of surface water, glaciers, and polar ice caps 2.4%, and other land surface water such as rivers, lakes, and ponds 0.6%. Additionally, a minute amount of the Earth's water is contained within biological bodies and manufactured products.\n",
"Water is amphoteric, meaning that it can exhibit properties of an acid or a base, depending on the pH of the solution that it is in; it readily produces both and ions. Related to its amphoteric character, it undergoes self-ionization. The product of the activities, or approximately, the concentrations of and is a constant, so their respective concentrations are inversely proportional to each other.\n",
"Category 1 Water - Refers to a source of water that does not pose substantial threat to humans and classified as \"clean water\". Examples are broken water supply lines, tub or sink overflows or appliance malfunctions that involves water supply lines.\n"
] |
Why do shadows "kiss"?
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This is because the sun is an "extended" light source, as opposed to a point light source. Because of this, there is an area called the [penumbra](_URL_1_), where the shadowing object creates a partial shadow. When two penumbras meet, it makes the "kissing" darker shadow.
See also [Shadow Blister Effect](_URL_0_)
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[
"Rather than depicting death as a winged angel the sculptor instead chose a skeleton. The eroticism of the kiss is hard to escape - the sculpture shows youth welcoming death as a partner. The sculpture is at once romantic and horrifying, which leads to the varying views of the people that view it. It attracts and repels at once, the urge to touch combines with the desire to flee.\n",
"Movement helps give the shadows character and brings them to life. Some shadows are performed with accessories attached to the hands or fingers to achieve movements or images not applicable to hands alone.\n",
"However, it has been argued that the act of kissing a persons forehead is not romantic. Instead such an act is purely neutral and should not be used when trying to transfer feelings of emotion, lust, love, or so on. It's been said to lack certain qualities that make other kisses more romantic and therefore should not be thought of as a gesture for expressing non-platonic love. It is even stated that the kiss is used as a means of imposing distance in certain situations.\n",
"\"The Kiss\" is an oil painting on canvas, measuring . It depicts a couple surrounded by darkness, with only a sliver of daylight showing through a window which is mostly covered by a curtain. They hold an embrace as they seemingly merge into one, their faces a single, featureless shape. Art critic Roberta Smith notes that Munch favored \"long, somewhat slurpy brush strokes that were more stained than painted\".\n",
"Throughout history, a kiss has been a ritual, formal, symbolic or social gesture indicating devotion, respect or greeting. It appears as a ritual or symbol of religious devotion. For example, in the case of kissing a temple floor, or a religious book or icon. Besides devotion, a kiss has also indicated subordination or, nowadays, respect.\n",
"Shadow Kiss is a vampire novel written by Richelle Mead. It is the third novel in the \"Vampire Academy\" series, and was preceded by \"Frostbite\". The release of the book pushed the Vampire Academy series into the \"New York Times\" Best Seller list for the first time, making its debut at #4. \"Shadow Kiss\" continues the story of the main character, Rose Hathaway and her education in becoming a Guardian.\n",
"\"Kissing You\" (or \"I'm Kissing You\") is a song by British singer Des'ree. It was written by the singer with Timothy Atack for Baz Luhrmann's 1996 film \"Romeo + Juliet\". The song was included on the film's soundtrack album and Des'ree's third studio album, \"Supernatural\" (1998). A pop ballad set in the key of A minor, the record uses a simple instrumentation consisting only of piano and string instruments. \"Kissing You\" featured in \"Romeo + Juliet\" when the title characters meet at a ball. The song was well received by critics for its emotional melody and toned-down production. First released as a single in Australia on 24 February 1997, it appeared on the ARIA Singles Chart and the UK Singles Chart. A music video accompanied the single, which included scenes from \"Romeo + Juliet\".\n"
] |
how usa is one of top polluters in most sources but is consistently ranked relatively favorably (in the middle) for how polluted it is?
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A lot of it is just how big the US is and how much the population and industrial centers are spread out.
If I have a country that is 100 square miles and pollutes x amount, and a country that is 1000 square miles and pollutes 5x amount, the second country pollutes 5 times as much as the first country but said pollution is spread out over 10 times the area, so would likely be only half as polluted.
Oversimplified but still pretty accurate. The USA is the third largest country by area behind Russia and Canada and ahead of china.
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[
"According to the WHO, India has14 out of the 15 most polluted cities in the world in terms of PM 2.5 concentrations. Other Indian cities that registered very high levels of PM2.5 pollutants are Delhi, Patna, Agra, Muzzaffarpur, Srinagar, Gurgaon, Jaipur, Patiala and Jodhpur, followed by Ali Subah Al-Salem in Kuwait and a few cities in China and Mongolia. \n",
"Agricultural nonpoint source (NPS) pollution is the largest source of water quality impairments throughout the U.S., based on surveys by state environmental agencies. NPS pollution is not subject to discharge permits under the federal Clean Water Act (CWA). EPA and states have used grants, partnerships and demonstration projects to create incentives for farmers to adjust their practices and reduce surface runoff.\n",
"In years to come, the public would achieve greater ways of accessing the information that corporations with excess pollutants withheld. The Toxic 100 is a form of newer information which is a list that includes one hundred companies industrial air polluters in the United States that are ranked by the quantity of pollution they produce and the toxicity of the pollutants. This data is determined by the Political Economy Research Institute (PERI) and calculated with factors such as winds carrying the pollution, height of smokestacks, and how much it impacts nearby communities.\n",
"A study jointly conducted by Indian Institute of Technology, Delhi (IIT-D) and Central Pollution Control Board (CPCB) reveals that Angul district is among the top ten most polluted Indian cities where the pollution level reached to a 'very alarmingly' level.\n",
"It has been ranked 2 in the year 2008 among the most polluted places in the world, mainly due to its poor air and water quality caused by nearby industrial sites. People who have been living in the town have a lot of complaints about their health due to the pollution emissions happening almost every night from chemical factories. As of 2018, the pollution has come down significantly.The City has a particular area called Square which is about 1.7km where most of the people hangout. It comprises 11 wards.\n",
"Community activists and environmental scholars, have effectively argued that major industrial polluters, like Exide, have been able to release massive amounts of pollution by exploiting goverment inaction regarding poor and minority populations that often live near these major sources of pollution. Specifically, it has been proposed that Exide, which is controlled by affluent white men, is continuously protected by local regulatory agencies so that the company has little responsibility in low-income, minority communities. For example, at a South Coast Air Quality Management District (SCAQMD) board hearing, the mayor of Maywood, Oscar Magana, thought that the Department of Toxic Substances Control and the SCAQMD, would have closed the Exide plant in Vernon much sooner if it had been placed in Beverly Hills, or any other affluent, predominantly white community.\n",
"4.Delhi is now considered the most polluted city in the world, according to the Brookings Institute, while at least two-and-a-half million premature deaths are blamed on poor air quality across the country as a whole.\n"
] |
the waco siege.
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a ups driver was delivering packages to the compound and one broke open showing weapons, inert grenades and black powder. UPS reported this to the sheriff who contacted the ATF. This info along with reports of automatic fire from the compound led to sucspision that the Brach Davidians were illegally modifying weapons to be fully automatic. The ATF got a search warrant and prepared a raid. The Davidians knew the raid was coming. During the raid shots were fired but it is still debated who shot first. During the ensuing firefight, 4 ATF agents were killed 16 wounded and 5 Davidians killed, but the compound was not successfully breached which led to the siege and the FBI taking over. Eventually the FBI tried to gas them out using tear gas, during this fire broke out in the compound which spread rapidly. 76 Davidians were killed in the fire and 9 escaped
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[
"The Waco siege was the siege of a compound belonging to the religious sect Branch Davidians, carried out by American federal and Texas state law enforcement, as well as the U.S. military, between February 28 and April 19, 1993. The Branch Davidians were led by David Koresh and were headquartered at Mount Carmel Center ranch in the community of Axtell, Texas, 13 miles (21 kilometers) east-northeast of Waco. Suspecting the group of stockpiling illegal weapons, the Bureau of Alcohol, Tobacco, and Firearms (ATF) obtained a search warrant for the compound and arrest warrants for Koresh and a select few of the group's members.\n",
"The Waco siege has been the subject of numerous documentary films and books. The first film was a made-for FBI and television docudrama film, \"\", which was made during the siege, before the April 19 assault on the church, and presented the initial firefight of February 28, 1993 as an ambush. The film's writer, Phil Penningroth, has since disowned his screenplay as pro-ATF \"propaganda\".\n",
"The Siege of Fort Vincennes (also known as the Siege of Fort Sackville or the Battle of Vincennes) was a Revolutionary War frontier battle fought in present-day Vincennes, Indiana won by a militia led by American commander George Rogers Clark over a British garrison led by Lieutenant Governor Henry Hamilton. Roughly half of Clark's militia were Canadien volunteers sympathetic to the American cause. After a daring wintertime march, the small American force was able to force the British to surrender the fort and in a larger frame the Illinois territory.\n",
"The Siege of San José del Cabo, from January to February 1848, was a prolonged battle of the Mexican–American War in which Mexican militia besieged a smaller force of American marines, sailors and Californio militia. The final engagement during the battle involved half of the American garrison, and a landing party from a reinforcing warship, which successfully lifted the siege.\n",
"The Siege of Béxar (or Béjar) was an early campaign of the Texas Revolution in which a volunteer Texian army defeated Mexican forces at San Antonio de Béxar (now San Antonio, Texas, US). Texians had become disillusioned with the Mexican government as President and General Antonio Lopez de Santa Anna's tenure became increasingly dictatorial. In early October, 1835, Texas settlers gathered in Gonzales to stop Mexican troops from reclaiming a small cannon. The resulting skirmish, known as the Battle of Gonzales, launched the Texas Revolution. Men continued to assemble in Gonzales and soon established the Texian Army. Despite a lack of military training, well-respected local leader General Stephen F. Austin was elected commander.\n",
"BULLET::::- February 28, 1993: Waco siege: Bureau of Alcohol, Tobacco and Firearms agents raided the Branch Davidian compound in Waco, Texas, with a warrant to arrest leader David Koresh on federal firearms violations. Four agents and 5 Davidians died in the raid.\n",
"The siege was defended against by a group of local insurgents commanded by Colonel . This siege is considered one of the most important battles of the second phase of the Mexican War for Independence.\n"
] |
Napoleonic Era and Uniforms (Nit-Picky Questions)
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So, there's a million questions. It would be beneficial if you reworded your question for a single question and ask a few over a few days.
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[
"In 1828, the greyish-blue trousers worn during the later stages of the Napoleonic Wars were replaced by dark blue \"Oxford mixture\" trousers for winter wear. White duck trousers were worn in summer until 1845. Although the fantastic profusion of gold and silver lace on officers' uniforms was checked, decorations for other ranks' uniforms such as fringed epaulettes, lace and badges became heavier and more ornate. The false-fronted \"Belgic\" shako, made famous by depictions of the Battle of Waterloo, was replaced soon after the Napoleonic Wars by a flaring, \"bell-topped\" shako. In the 1840s, the tapering \"Albert\" shako, with peaks both fore and aft, was adopted. Guards units wore the towering bearskin adopted after Waterloo, while most Highland regiments wore the 'feather bonnet', decorated with ostrich plumes. On campaign in India, the low-crowned \"Kilmarnock\" forage cap was often worn, sometimes with a white cloth cover that shaded the neck and the back of the head from the sun. The infamous leather stock, designed to force the wearer to keep his head erect, was retained until 1855. Trimming it down, or even soaping it to reduce the discomfort to the wearer, was a disciplinary offence.\n",
"French style uniform and court dress were common during the early stage of the Tanzimat modernization period. After the French defeat in the Franco-Prussian War, which forced the Ottoman government to search for other role models, German and British style uniforms became popular. During World War I, the officer uniforms were mainly based on the German model. The Crimean War was the first war effort in which the modern army took part, profiling itself as a decent force.\n",
"The ornamental peak of the military uniform was reached in the early 19th century in Western Europe. Sometimes the Napoleonic Wars are identified as being the acme of colourful and ornate uniforms, but actually the several decades of relative peace that followed were a time of even more decorative styles and embellishments. The Napoleonic soldier on campaign was likely to present a shabby and nondescript appearance as unsuitable peacetime dress quickly deteriorated or was replaced with whatever local substitutes were available. Until later on in the century dyes were primitive and different batches of uniforms worn by the same unit might present differing shades, especially after exposure to rain and sun. The white uniforms popular amongst many armies through the 18th and early 19th centuries soiled easily and had to be pipeclayed to retain any semblance of cleanliness. Green as worn by Jäger and Rifle regiments proved particularly prone to fading until suitable chemical dyes were devised in the 1890s. British soldiers were known for their striking red clothing (hence the name \"Redcoats\"). This was actually a fairly dull shade of madder red until the general adoption of scarlet for tunics in the 1870s. The American industrial revolution began in the Blackstone Valley, of Massachusetts and Rhode Island, with early textiles, from 1791. Among the earliest manufacturers of US military uniforms was the Capron Mills at Uxbridge, Massachusetts from 1820.\n",
"Until the middle of the 19th century only officers and warrant officers in the Royal Navy wore regulated uniforms. Through the 18th century to the Napoleonic Wars navy officers had a form of dress broadly resembling that of army officers, though in dark blue with white facings. In the early 19th century Royal Navy officers developed a more distinctive form of uniform comprising (in full dress) a cocked hat, dark blue coatee with white collar and cuffs, dark blue or white trousers, or breeches.\n",
"The first fifteen years of this century influenced the appearance of military uniforms until the 1850s. In particular, some French uniforms – notably those of the cavalry regiments of the Imperial Guard – are considered as being amongst the most striking and distinctive of the time. The cost of the French uniforms varied widely, going from 200-250 francs for a line infantryman's outfit to 2000 francs for a cuirassier's uniform. Cavalrymen of the Guard had no fewer than 10 different uniforms. One justification for the expensive parade dresses of the Guard was that they would \"lead the people of the conquered nations to regard the French uniforms with unreserved astonishment\". As a general trend France and other European states replaced their bicornes by feathered shakos or crested helmets\n",
"BULLET::::- Uniformes militaires des troupes françoises et étrangères l'Infanterie Cavalerie Dragons et Hussards. French eighteenth-century army uniforms, which Spanish uniforms of that period—such as those of the Royal University Militias—resembled.\n",
"France followed Prussia's lead, introducing a tunic for their line infantry in 1845. In 1851, the US Army introduced a long type of tunic which they called a \"frock coat\". The British eventually followed suit in 1855, their initial French-style double breasted tunic being replaced by a single breasted version in the following year. The tunic became almost universal military wear; at the start of the twentieth century, when the need for some kind of concealment became apparent, armies changed to drab coloured uniforms, the British and Americans in 1902, the Germans in 1910. In the British Army, the tunic continued as a field uniform until the introduction of Battle Dress in 1938; the tunic continues to be worn for formal and ceremonial occasions.\n"
] |
what is the evolutionary benefit to a species, such as the praying mantis, to have the female kill the male after copulation?
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By eating the male, the female gains a lot of nutrients, which will enable her to have healthier and stronger offspring. In this way, there is a higher chance that the genes of both the male and the female are carried on.
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[
"Copulation in a monogynous male is a sacrificial system. They not only cause genital damage to themselves but in many cases die during copulation spontaneously such as \"Argiope aurantia\" or are cannibalized by the female. This can be observed in many spider species such as the red back spider which consumes the male either during or right after copulation if the male is not quick enough to escape. The size and age of the female play a role on whether or not the male was able to escape. They usually were not successful in the attempt to escape if the female was older and heavier making her much more dominant than the male. Another factor on the survival or demise of the male is the duration of the copulation. If there is a high copulation time the chances of him being eaten are much higher. If the copulation has a duration of ten seconds or more the chances of him being eaten are much greater than those that jump off before ten seconds. Monogyny increases a male's chance of paternity when there is a male biased ratio in the population. When males make up a large majority of the population, the likelihood of finding multiple females is slim. Thus the males will mate with the first female they encounter. Mate guarding her from other males is more beneficial than looking for another female because the odds of meeting another female in a male biased population are against him.\n",
"Copulation is injurious for the female beetle. The male possesses penile spines which damage the female reproductive tract. The female may forcefully kick the male during copulation, ending the mating. It is possible that male may benefit from harming the female because the injury could reduce matings or mating success with other males, or increase her egg production. When the female is experimentally prevented from kicking the male (by removal of the hind legs), matings continued for longer than usual, and injury increased. However, the amount of time before she became receptive again and the rate of oviposition were not affected. This suggests that penile spines do not increase the reproductive success of males, and it is suspected that the spines do not increase reproductive success for either sex, and may have no adaptive value.\n",
"In other species males voluntarily self-amputate a pedipalp prior to mating and thus the mutilation is not driven by sexual cannibalism. This has been hypothesized to be due to an increased fitness advantage of half or full eunuchs. Upon losing a pedipalp males experience a significant decrease in body weight that provides them with enhanced locomotor abilities and endurance, enabling them to better search for a mate and mate-guard after mating. This is referred to as the \"gloves-off\" theory.\n",
"Males of the \"Pisaura mirabilis\" species feign death to avoid being cannibalized by a female prior to copulation. When males feign death, their success in reproduction depends on the level of aggressiveness the female displays. Research has shown that in the \"Nephilengys livida\" species, female aggressiveness had no effect on the likelihood of her cannibalizing a potential mate; male aggressiveness and male-male competition determined which male the female cannibalized. Males with aggressive characteristics were favored and had more chance of mating with a female.\n",
"A wide range of reproductive strategies have been noted in ant species. Females of many species are known to be capable of reproducing asexually through thelytokous parthenogenesis. Secretions from the male accessory glands in some species can plug the female genital opening and prevent females from re-mating. Most ant species have a system in which only the queen and breeding females have the ability to mate. Contrary to popular belief, some ant nests have multiple queens, while others may exist without queens. Workers with the ability to reproduce are called \"gamergates\" and colonies that lack queens are then called gamergate colonies; colonies with queens are said to be queen-right.\n",
"As with most mantis species, \"S. viridis\" males are frequently the victims of sexual cannibalism. A female produces an ootheca within a few days of mating and can produce several before she ends her lifecycle. Each ootheca produces up to 300 nymphs when it hatches. This species has also been noted to have reproduced parthenogenically.\n",
"Pharaoh ant copulation, like that of many social insects, is harmful to the female. The penis valve contains sharp teeth, which latch onto a thick, soft cuticular layer in the female. This method of copulation too has an evolutionary basis. The teeth ensure sex lasts long enough for sufficient sperm transfer. Also, the pain caused to the female may, in some ways, lessen her desire to mate again.\n"
] |
if someone is on death row and has a medical issue causing them the die sooner than their execution date, why would they be given medical help?
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Up until the moment the executioner turns the key, the state must provide care for their convicted felons. The logic behind this is that up until that last moment, the execution is not 100% certain. There are years of appeals, and the governor might still pardon the convicted at the last moment. Also, allowing someone to die from a disease without treatment can be considered as cruel and unusual punishment.
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[
"Physicians can cause a patient's death \"actively\" (for example, by administering a fatal drug) or \"passively\" (by withholding food, water, or medical care that would prolong life). This option may be offered to patients who are terminally ill and are severely disabled or in great pain with no hope of recovery. If the patient is unable to communicate or consent, sometimes family members may be asked to decide. This option is called \"euthanasia,\" \"assisted suicide,\" or \"mercy killing.\"\n",
"It would also have been the case that various individuals would have died as a result of the unsanitary conditions of their imprisonment, but again this is not recorded within the number of executions.\n",
"A person can be declared legally dead after they are exposed to \"imminent peril\" and fail to return—as in a plane crash, as portrayed in the movie \"Cast Away\". In these cases courts generally assume the person was killed, even though the usual waiting time to declare someone dead has not elapsed. Sentell also says, \"The element of peril accelerates the presumption of death.\" This rule was enacted after the attack on the World Trade Center, so that authorities could release death certificates. Although people presumed dead sometimes turn up alive, it is not as common as it used to be. In one case where this occurred, a man named John Burney disappeared in 1976 while having financial problems, and later reappeared in December 1982. His company and wife had already received the death benefits—so, on returning, the life insurance company sued him, his wife, and his company. In the end, the court ruled Burney's actions fraudulent.\n",
"If clinical death is expected due to terminal illness or withdrawal of supportive care, often a Do Not Resuscitate (DNR) or \"no code\" order is in place. This means that no resuscitation efforts are made, and a physician or nurse may pronounce legal death at the onset of clinical death.\n",
"However, there have been no executions since 23 June 1976, although death sentences were handed down continuously by the High and Supreme Courts for murder and drug trafficking convictions. These were automatically commuted to life in prison. The government decided to reinstate capital punishment in 2004 for cases of rape, drug trafficking and murder after the assassination of High Court judge Sarath Ambepitiya. Perjury that results in execution of an innocent person, treason, armed robbery, some military offences and certain crimes committed with the use of a gun (such as kidnapping, extortion, human trafficking, assault on a public servant) can also result in the death penalty.\n",
"Amnesty also reports allegations of abuse of suspects during these interrogations. There are reports of physical abuse, sleep deprivation and denial of food, water and use of a toilet. One of its biggest criticisms is that inmates usually remain for years (and sometimes decades) on death row without ever actually being informed of the date of their execution prior to the date itself, so inmates suffer due to the uncertainty of not knowing whether or not any given day will be their last. According to Amnesty International, the intense and prolonged stress means many inmates on death row have poor mental health, suffering from the so-called death row phenomenon. The failure to give advanced notice of executions has been stated by the United Nations Human Rights Committee to be incompatible with articles 2, 7 and 10 of the International Covenant on Civil and Political Rights.\n",
"There is concern over large numbers of deaths among inmates. Notably 5 prisoners died over one month in autumn 2017, 4 believed to be by suicide. Deborah Coles of Inquest said, “The fact these deaths occurred within days of arrival at the prison when prisoners are known to be most vulnerable, raise concerns about the processes for identifying and managing risk.”\n"
] |
it's common knowledge that exercising regularly and pushing yourself is good for your health and heart, but how does that logic work that the harder you work your heart, the healthier it becomes, instead of wearing it out?
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The human body is a fascinating thing. It has been developed to be able to adapt to different lifestyles. When working out, you are essentially telling your body that for your lifestyle, you require stronger muscles. The body has learned to oblige to this, thus makes muscles stronger by adding more protein to the muscle cells (contrary to popular belief, the muscles do not gain more cells, the cells get more muscle protein, and become bigger in the process).
If strong muscles are no longer needed for your lifestyle, the body will adapt to that as well, making you lose muscle.
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[
"Physical health is also something that needs to be worked on daily, whether it is exercise, healthy eating, or relaxation. states that blood pressure, heart rate, and respiration rate will all decrease when one is relaxed. This means that a person's heart does not beat as fast and their breathing is shallow, helping one's body have time to rest. This will reduce the extra stress that these things can do to the body if they are over worked. Muscle tension will decrease. If one's muscle tension is decreased they are not burning up extra energy that they may need later in the day. Metabolism can also decrease; this is mostly seen in hibernation and sleep and that gives the body extra time to rest and focus on other aspect that it needs to. This could be seen as a good or bad thing, depending on the overall quality of health. People who practice relaxation have said to be able to tolerate pain better both mentally and physically.\n",
"Regular exercise makes these systems more efficient by enlarging the heart muscle, enabling more blood to be pumped with each stroke, and increasing the number of small arteries in trained skeletal muscles, which supply more blood to working muscles. Exercise improves not just the respiratory system but the heart by increasing the amount of oxygen that is inhaled and distributed to body tissue. A 2005 Cochrane review demonstrated that physical activity interventions are effective for increasing cardiovascular fitness.\n",
"If your doctor deems it necessary, a stress TTE may be performed. This can be accomplished by either exercising on a bike or treadmill, or by medicine given through an IV along with a contrast agent to make your bodily fluids show up brighter. This allows a comparison between your heart at rest and your heart when it is beating at a faster rate. (Transthoracic Echocardiogram, n.d.)\n",
"Physical fitness has proven to result in positive effects on the body's blood pressure because staying active and exercising regularly builds up a stronger heart. The heart is the main organ in charge of systolic blood pressure and diastolic blood pressure. Engaging in a physical activity raises blood pressure. Once the subject stops the activity, the blood pressure returns to normal. The more physical activity that one engages in, the easier this process becomes, resulting in a more ‘fit’ individual. Through regular physical fitness, the heart does not have to work as hard to create a rise in blood pressure, which lowers the force on the arteries, and lowers the overall blood pressure.\n",
"In most cases, the specific reason that exercise is not tolerated is of considerable significance when trying to isolate the cause down to a specific disease. Dysfunctions involving the pulmonary, cardiovascular or neuromuscular systems have been frequently found to be associated with exercise intolerance, with behavioural causes also playing a part.\n",
"Studies have shown that exercise reduces stress. Exercise effectively reduces fatigue, improves sleep, enhances overall cognitive function such as alertness and concentration, decreases overall levels of tension, and improves self-esteem. Because many of these are depleted when an individual experiences chronic stress, exercise provides an ideal coping mechanism. Despite popular belief, it is not necessary for exercise to be routine or intense in order to reduce stress. As little as five minutes of aerobic exercise can begin to stimulate anti-anxiety effects. Further, a 10-minute walk may have the same psychological benefits as a 45-minute workout, reinforcing the assertion that exercise in any amount or intensity will reduce stress.\n",
"When it comes to explicitly alternating mental and physical exercise sections, proponents rationalize that physical activity induces an elevated heart-rate and increases in stress, which mimics conditions in which athletes need their mental skills the most. It is believed that these conditions make training more functional and there is some limited scientific evidence supporting effectiveness because of this type of approach. \n"
] |
How much variety is there between single celled organisms? Would two of my red blood cells be completely identical down to the smallest measure?
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Two different questions really. Red blood cells aren't organisms. 1) Vast. 2) Potentially, but unlikely
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[
"All white blood cells are nucleated, which distinguishes them from the anucleated red blood cells and platelets. Types of leukocytes can be classified in standard ways. Two pairs of broadest categories classify them either by structure (granulocytes or agranulocytes) or by cell lineage (myeloid cells or lymphoid cells). These broadest categories can be further divided into the five main types: neutrophils, eosinophils, basophils, lymphocytes, and monocytes. These types are distinguished by their physical and functional characteristics. Monocytes and neutrophils are phagocytic. Further subtypes can be classified.\n",
"A typical human red blood cell has a disk diameter of approximately 6.2–8.2 µm and a thickness at the thickest point of 2–2.5 µm and a minimum thickness in the centre of 0.8–1 µm, being much smaller than most other human cells. These cells have an average volume of about 90 fL with a surface of about 136 μm, and can swell up to a sphere shape containing 150 fL, without membrane distension.\n",
"A cell type is a classification used to distinguish between morphologically or phenotypically distinct cell forms within a species. A multicellular organism may contain a number of widely differing and specialized cell types, such as muscle cells and skin cells in humans, that differ both in appearance and function yet are genetically identical. Cells are able to be of the same genotype, but different cell type due to the differential regulation of the genes they contain. Classification of a specific cell type is often done through the use of microscopy (such as those from the cluster of differentiation family that are commonly used for this purpose in immunology). Recent developments in single cell RNA sequencing facilitated classification of cell types based on shared gene expression patterns. This has led to the discovery of many new cell types in e.g. mouse cortex, hippocampus, dorsal root ganglion and spinal cord.\n",
"The red blood cell membrane comprises a typical lipid bilayer, similar to what can be found in virtually all human cells. Simply put, this lipid bilayer is composed of cholesterol and phospholipids in equal proportions by weight. The lipid composition is important as it defines many physical properties such as membrane permeability and fluidity. Additionally, the activity of many membrane proteins is regulated by interactions with lipids in the bilayer.\n",
"Among dividing cells, there are multiple levels of cell potency, the cell's ability to differentiate into other cell types. A greater potency indicates a larger number of cell types that can be derived. A cell that can differentiate into all cell types, including the placental tissue, is known as \"totipotent\". In mammals, only the zygote and subsequent blastomeres are totipotent, while in plants, many differentiated cells can become totipotent with simple laboratory techniques. A cell that can differentiate into all cell types of the adult organism is known as \"pluripotent\". Such cells are called meristematic cells in higher plants and embryonic stem cells in animals, though some groups report the presence of adult pluripotent cells. Virally induced expression of four transcription factors Oct4, Sox2, c-Myc, and Klf4 (Yamanaka factors) is sufficient to create pluripotent (iPS) cells from adult fibroblasts. A multipotent cell is one that can differentiate into multiple different, but closely related cell types. Oligopotent cells are more restricted than multipotent, but can still differentiate into a few closely related cell types. Finally, unipotent cells can differentiate into only one cell type, but are capable of self-renewal. In cytopathology, the level of cellular differentiation is used as a measure of cancer progression. \"Grade\" is a marker of how differentiated a cell in a tumor is.\n",
"The size of cells has been found to vary based on the type of \"Tetraspora\" species and the type of climatic zone the species is found in. On average the diameter of species in the genus \"Tetraspora\" ranges from 6-13 μm, with the species in the tropics usually being the smallest (6-9 μm), followed by the temperate zone species (6-14 μm), and the polar species (7.5-13 μm). The difference in cell size therefore also impacts sizes of the colonies, but sizes of colonies also vary with whether the cells are residing in stagnant or flowing water. In stagnant water, colonies may range from 5–10 cm in length, while in flowing water, colonies may reach lengths up to 50 cm. In addition to impacting colony size, the type of water (stagnant or free flowing) also impacts the morphology of the colonies. Most macroscopic colonies of \"Tetraspora\" are cylindrical in nature, but in stagnant water colonies may appear as short sacs and clubs with thalli that resemble balloons. Flowing water colonies on the other hand, tend to form narrow cylindrical structures with the thalli also being more or less cylindrical and sometimes can be lightly rounded at the sheaths.\n",
"Using this method, Fulwyler found that human white blood cells formed three distinct peaks when their volumes were plotted on a histogram, and by microscopically examining cells from each peak, he determined that the smallest-volume peak predominantly contained lymphocytes, the intermediate-volume peak contained neutrophils, and the largest-volume peak contained a mixture of granulocytes and monocytes. Fulwyler's technique was applied by other researchers to generate automated neutrophil counts, although counts for other cell types were not reliable due to the low number of cells counted. In 1983, the Coulter S Plus system, a commercial analyzer that produced a three-part differential of neutrophils, monocytes and lymphocytes based on cell size histograms, was introduced. The principle of identifying white blood cells by their sizes is still used in many hematology analyzers, although other techniques are used to improve discrimination between white blood cell types.\n"
] |
Sickle Cell Anemia and UVR / Melanin Evolution Correlation?
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It is because the sickle cell hemoglobin gene when it is heterozygous (meaning only one copy of one of your chromosomes and the other chromosome has a normal hemoglobin) protects against malaria. Since malaria is much more prevalent in tropical locations and so is darker skin, the sickle cell trait is selected for by evolution. In colder climates, where the population tends to have lighter skin and malaria is absent or very rare, there is no selective pressure to have the sickle cell trait and hence the disease is very uncommon.
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[
"The most important genetic alteration associated with poor prognosis in uveal melanoma is inactivation of BAP1, which most often occurs through mutation of one allele and subsequent loss of an entire copy of chromosome 3 (monosomy 3) to unmask the mutant copy. Because of this function in inactivation of BAP1, monosomy 3 correlates strongly with metastatic spread Where BAP1 mutation status is not available, gains on chromosomes 6 and 8 can be used to refine the predictive value of the monosomy 3 screen, with gain of 6p indicating a better prognosis and gain of 8q indicating a worse prognosis in disomy 3 tumors. In rare instances, monosomy 3 tumors may duplicate the BAP1-mutant copy of the chromosome to return to a disomic state referred to as isodisomy. Thus, isodisomy 3 is prognostically equivalent to monosomy 3, and both can be detected by tests for chromosome 3 loss of heterozygosity. Monosomy 3, along with other chromosomal gains, losses, amplifications, and LOH, can be detected in fresh or paraffin-embedded samples by virtual karyotyping.\n",
"Viewed broadly then, biological and environmental factors interact with a person's genes in ways which may increase or decrease the risk for developing schizoaffective disorder; exactly how this happens (the biological mechanism) is not yet known. Schizophrenia spectrum disorders, of which schizoaffective disorder is a part, have been increasingly linked to advanced paternal age at the time of conception, a known cause of genetic mutations. The physiology of people diagnosed with schizoaffective disorder appears to be similar, but not identical, to that of those diagnosed with schizophrenia and bipolar disorder; however, human neurophysiological function in normal brain and mental disorder syndromes is not fully understood.\n",
"The most important genetic alteration associated with poor prognosis in uveal melanoma is loss of an entire copy of Chromosome 3 (Monosomy 3), which is strongly correlated with metastatic spread. Gains on chromosomes 6 and 8 are often used to refine the predictive value of the Monosomy 3 screen, with gain of 6p indicating a better prognosis and gain of 8q indicating a worse prognosis in disomy 3 tumors. In rare instances, monosomy 3 tumors may duplicate the remaining copy of the chromosome to return to a disomic state referred to as isodisomy. Isodisomy 3 is prognostically equivalent to monosomy 3, and both can be detected by tests for chromosome 3 loss of heterozygosity.\n",
"Further evidence for a non-genetic etiology of diseases like schizophrenia, Ewald also points out, comes from concordance studies on identical twins, which measure the percentage of identical twins who both develop a disease. A concordance of 100% indicates a primarily genetic disease, which is not really influenced by environmental factors like infection, nutrition, or toxins. Huntington's disease, for example, has a concordance rate of 100%, indicating a predominately genetic etiology. However, when the concordance rate is lower, this indicates environmental factors like infectious microbes or toxin exposure are playing a causal role. Schizophrenia's concordance is approximately 35-60%, suggesting, says Ewald, that microbes are etiologically involved. Another example is breast cancer: Ewald notes that in the case of identical twins, when one twin develops breast cancer, the other twin has only a 10% to 20% chance of developing the disease, and this concordance rate of just 20% again indicates that environmental factors like infectious microbes or toxins are likely playing large causal roles in breast cancer.\n",
"Albinism may manifest itself as oculocutaneous (OCA) or just ocular (OA). There occur at least ten different types of OCA and four types of OA. OCA refers to a group of autosomal recessive disorders in which melanin is reduced or even absent leading to pale skin with increased risk of skin cancer. OCA1 is caused due to mutations in tyrosinase gene affecting its catalytic or synthetic activity. OCA2 is a condition where \"TYR\" gene is not mutated but the P polypeptide is. Mutational defects in TRP-1 protein leads to OCA3.\n",
"Mutations in the OCA2 gene cause a disruption in the normal production of melanin; therefore, causing vision problems and reductions in hair, skin, and eye color. Oculocutaneous albinism caused by mutations in the OCA2 gene is called oculocutaneous albinism type 2. The prevalence of OCA type 2 is estimated at 1/38,000-1/40,000 in most populations throughout the world, with a higher prevalence in the African population of 1/3,900-1/1,500. Other diseases associated with the deletion of the OCA2 gene are Angelman syndrome (light-colored hair and fair skin) and Prader-Willi syndrome (unusually light-colored hair and fair skin). With both these syndromes, the deletion often occurs in individuals with either syndrome.\n",
"The molecular defects in XP cells result in a greatly elevated induction of mutations in sun-exposed skin of affected individuals. This increased mutation frequency probably accounts for the pigmentation changes and the skin cancers. Examination of mutations in the p53 gene in tumors from XP patients reveal p53 mutations characteristic of UV exposure in the majority of tumors As with all genetic disorders, genetic counseling and psychological support is appropriate for the families to discuss probability of occurrence in future pregnancies, feelings of isolation and concern about career prospects. Although there is no cure for xeroderma pigmentosum. The most common fate for individuals with XP is early death from cancer.\n"
] |
why is it that when my battery dies on my iphone it takes 10 minutes to turn back on while connected to a charger?
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Apple makes sure that the phone is charged to a minimum % (3%-5%?) before it turns on, to make sure it doesn't die again when you unplug it.
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[
"If a battery has been completely discharged (e.g. the car lights were left on overnight) and next is given a fast charge for only a few minutes, then during the short charging time it develops only a charge near the interface. The battery voltage may rise to be close to the charger voltage so that the charging current decreases significantly. After a few hours this interface charge will spread to the volume of the electrode and electrolyte, leading to an interface charge so low that it may be insufficient to start a car.\n",
"Consider a battery that has been completely discharged (such as occurs when leaving the car lights on overnight, a current draw of about 6 amps). If it then is given a fast charge for only a few minutes, the battery plates charge only near the interface between the plates and the electrolyte. In this case the battery voltage might rise to a value near that of the charger voltage; this causes the charging current to decrease significantly. After a few hours this interface charge will spread to the volume of the electrode and electrolyte; this leads to an interface charge so low that it may be insufficient to start the car. As long as the charging voltage stays below the gassing voltage (about 14.4 volts in a normal lead–acid battery), battery damage is unlikely, and in time the battery should return to a nominally charged state.\n",
"It is powered by a 5100 mAh battery, one of the highest-capacity batteries in its class, which can give up to three days of battery backup in normal use. It has a physical power saver switch, which extends battery life and reverse charging feature. This phone works with a 24W quick charger that can rapidly charge the battery. Rapid charge function will only be utilized when the phone is turned off completely.\n",
"Critics of this phone state that its battery lasts for only two days even in stand-by mode and then needs to be recharged. Also, at the beginning of its production, the phone was said to sometimes hang or switch off. This was fixed in later versions of firmware.\n",
"It also comes with Battery Care, Sony's proprietary charging algorithm, that controls the charging process of the phone through machine learning. It recognizes the user's charging habits for a certain period and automatically adjusts itself to the pattern, for example an overnight charge, by stopping the initial charging to about 90 percent, and then continuing it until full from where it left off the next day. This effectively prevents the unnecessary damage to the battery's cells from excessive heat and current due to overcharging, further increasing the battery's life span.\n",
"The Xperia XZ2 also comes with Battery Care, Sony's proprietary charging algorithm that controls the charging process of the phone through machine learning. It recognizes the user's charging habits for a certain period and automatically adjusts itself to the pattern, for example an overnight charge, by stopping the initial charging to about 80-90 percent, and then continuing it until full from where it left off the next day. This effectively prevents the unnecessary damage to the battery's cells from excessive heat and current due to overcharging, further increasing the battery's life span.\n",
"The phone shipped with an extra battery and extra stylus. The supplied power cable could be used as a travel charger or to plug into the included cradle, which could charge the phone and an extra battery simultaneously. Despite two batteries, the phone needed to be plugged in regularly. Swapping charged batteries would eventually result in a phone reset---a complete loss of user data.\n"
] |
What is happening during the onset, peak and duration of a local anesthetic?
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Local anesthetics, like lidocaine, work by stabilizing the membrane of cells. What this means is that they reversibly decrease the rate of depolarization and repolarization of excitable membranes. One such type of membrane is the cell membrane of pain-sensing neurons. By blocking the ability of the nerve membrane to depolarize, the local anesthetic blocks the ability of the nerve to send a signal to the brain, thereby eliminating the sensation of pain while the anesthetic effects are active. They do this mainly by inhibiting sodium influx into the cells by blocking sodium-specific voltage-gated channels.
To really understand this, you'll have to review how nerves actually transmit signals. Then you'll be able to see how blocking a part of that cascade we can stop the signal transmission.
Hope this helps, feel free to message me if you have further questions.
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[
"Induction of anesthesia is facilitated by diffusion of an inhaled anesthetic drug into the brain and spinal cord. Diffusion throughout the body proceeds until the drug's partial pressure within the various tissues is equivalent to the partial pressure of the drug within the lungs. Healthcare providers can control the rate of anesthesia induction and final tissue concentrations of the anesthetic by varying the partial pressure of the inspired anesthetic. A higher drug partial pressure in the lungs will drive diffusion more rapidly throughout the body and yield a higher maximum tissue concentration. Respiratory rate and inspiratory volume will also effect the promptness of anesthesia onset, as will the extent of pulmonary blood flow.\n",
"The immediate time after anesthesia is called emergence. Emergence from general anesthesia or sedation requires careful monitoring because there is still a risk of complication. Nausea and vomiting are reported at 9.8% but will vary with the type of anesthetic and procedure. There is a need for airway support in 6.8%, there can be urinary retention (more common in those over 50 years of age) and hypotension in 2.7%. Hypothermia, shivering and confusion are also common in the immediate post-operative period because of the lack of muscle movement (and subsequent lack of heat production) during the procedure.\n",
"Like other local anesthetics belonging in the amide group trimecaine decreases the cell membrane permeability, causes depolarization and shortens the action potential. Anesthetic effect starts in 15 minutes and remains 60–90 minutes. Its biological half-life is ca. 90 minutes. 10% of trimecaine is excreted unchanged (90% as its metabolites). It passes through the hematoencephalic and placental barriers.\n",
"In dentistry, the most commonly used local anesthetic is lidocaine (also called xylocaine or lignocaine), a modern replacement for procaine (also known as novocaine). Its half-life in the body is about 1.5–2 hours. Other local anesthetic agents in current use include articaine (also called septocaine or ubistesin), bupivacaine (a long-acting anesthetic), Prilocaine (also called Citanest), and mepivacaine (also called Carbocaine or Polocaine). A combination of these may be used depending on the situation. Most agents come in two forms: with and without epinephrine (adrenaline) or other vasoconstrictor that allow the agent to last longer. This controls bleeding in the tissue during procedures. Usually the case is classified using the ASA Physical Status Classification System before any anesthesia is given.\n",
"Local anesthesia is an anesthetic drug (which can be given as a shot, spray, or ointment) that numbs only a small, specific area of the body (for example, a foot, hand, or patch of skin). With local anesthesia, a person is awake while sedated. Local anesthesia lasts for a short period of time and is often used for minor outpatient procedures (when patients come in for surgery and can go home that same day). For someone having outpatient surgery in a clinic or doctor's office (such as the dentist or dermatologist), this anesthetic is likely used. The medicine can numb the area during the procedure and for a short time afterwards to help control post-surgery discomfort. \n",
"The dose of local anesthesia is often reduced when a patient has any systemic health implications or habits which may cause an interference. From time to time the local anaesthetic itself should be reduced (therefore reducing the maximum dose). This is particularly done when alcoholism, anaemia (if using Prilocaine), anorexia, bradycardia or GORD is concerned. On other occasions the vasoconstrictor used (often adrenaline) must be reduced when an individual suffers from angina, bradycardia, chronic bronchitis, cardia disarrhythmia, COPD or glaucoma. These include drug abuse, calcium channel blocker containing medications, beta blocker medications or liver disease as this impairs the metabolism.\n",
"The developmental phase is defined as the time between the initial exposure to the causative agent or incident, until the onset of clinical signs. It generally lasts 24–60 hours, and is the best time to treat a laminitis episode. Clinical laminitis may be prevented if cryotherapy (icing) is initiated during the developmental phase.\n"
] |
why does ukip have so many meps as opposed to other government positions?
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UKIP supporters really, really, *really* hate the EU.
Most everyone else just doesn't care about MEPs.
So UKIP voters are more energized in European elections than the general public.
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[
"UKIP had 24 MEPs elected at the 2014 European elections, which was its highest tally to date. By the time of the 2019 elections, it had three MEPs following multiple defections. It won no seats in those elections and there are now no UKIP MEPs in the European Parliament.\n",
"In the 2009–14 parliament, UKIP ranked 76th out of 76 for attendance, took part in 61% of votes, and had three of the six lowest attending MEPs, which led to criticism from other parties and ex-UKIP MEPs that low participation may damage British interests. Between July 2014 and May 2015, its 23 MEPs maintained their record as the least active, participating on average in only 62.29% of votes. In response to criticism of low participation by UKIP MEPs in the EU Parliament, Farage has said that \"Our objective as MEPs is not to keep voting endlessly for more EU legislation and to take power away from Westminster.\"\n",
"UKIP supporters are sometimes nicknamed \"kippers\". In May 2017, in response to large defections from the party, Goodwin said \"Former Kippers did not walk but literally sprinted over to the Conservatives.\"\n",
"UKIP's support has been particularly weak in Scotland, where it has no representatives in the devolved parliament. UKIP fielded candidates at the Scottish Parliament election on 5 May 2011, when its platform included a commitment to keep the Scottish Parliament in Edinburgh, while replacing the separately-elected Members of the Scottish Parliament with the Members of the House of Commons elected in Scotland.\n",
"MEPs sit in a parliament with less powers over certain subjects than national parliaments (health and education, law & order or defence), but significant power over economic matters (e.g. environmental standards, consumer protection, trade, employment law). Yet their public profile in their home state is typically lower than that of national parliamentarians, especially because national media in many countries tend to report much less often about debates and votes in the European Parliament than in their national Parlament, a trend that is shifting since recently.\n",
"As a result of its hard Eurosceptic approach, UKIP does not recognise the legitimacy of the European Parliament, and under Sked's leadership refused to take any of the EP seats that it won. This changed after 1997, when the party decided that its elected representatives would take such seats to publicise its anti-EU agenda.\n",
"UKIP gained its first elected MP with Douglas Carswell winning the seat of Clacton by 12,404 votes on 9 October 2014. His 21,113 votes (59.75%) represented a 44% swing from the Conservative party, from whom Carswell had defected, his resignation having triggered the Clacton by-election.\n"
] |
- why is, what seems like rape so prevalent in the animal kingdom?
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Because most animals don't have morals. Humanity has gotten to a point of intelligence and society that we don't need to allow ourselves to just procreate willy-nilly.
Cats, dogs, and other animals rape as part of procreation because they don't have the morals, the intelligence, the sense of caring for others, that says "maybe they don't want sex".
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[
"It has been noted that behavior resembling rape in humans is observed in the animal kingdom, including ducks and geese, bottlenose dolphins, and chimpanzees. Indeed, in orangutans, close human relatives, copulations of this nature may account for up to half of all observed matings. Such behaviors, referred to as 'forced copulations', involve an animal being approached and sexually penetrated as it struggles or attempts to escape. These observations of forced sex among animals are not controversial. What is controversial is the interpretation of these observations and the extension of theories based on them to humans. \"Thornhill introduces this theory by describing the sexual behavior of scorpionflies. In which the male may gain sex from the female either by presenting a gift of food during courtship or without a nuptial offering, in which case force is necessary to restrain her.\"\n",
"It is hypothesized that rape is homologous to similar behavior in other animals. \"Human rape appears not as an aberration but as an alternative gene-promotion strategy that is most likely to be adopted by the 'losers' in the competitive, harem-building struggle. If the means of access to legitimate, consenting sex is not available, then a male may be faced with the choice between force or genetic extinction.\"\n",
"Rape and sexual violence are also prevalent in South Africa because of confusion about what is to be regarded as rape. Certain acts of sexual coercion may not be legally distinguishable. While the criminal offense of rape is condemned by the society, many rapes or sexual assaults might not be recognized as such and thus are not thought to be unacceptable behavior.\n",
"A rape is a traditional territorial sub-division of the county of Sussex in England, formerly used for various administrative purposes. Their origin is unknown, but they appear to predate the Norman Conquest. Historically the rapes formed the basis of local government in Sussex.\n",
"Thornhill and Palmer's \"A Natural History of Rape\" investigates the evolutionary causes of sexual coercion, particularly of rape, and suggests that such behaviour is a result of sexual selection, rather than Darwinian natural selection.\n",
"The 'rape as a by-product' explanation holds that rape behaviour evolved as a by-product of other psychological adaptations in men to obtain many mates. This adaptation not only leads to rape but a number of other behaviours including overrating female sexual interest, a desire for sexual variety, coercion, and sexual arousal which is not dependent on the consent of mate.\n",
"Researchers have attempted to explain the high rate of rape in South Africa and have connected it to the traditional and cultural norms embedded within the society. Certain norms like the belief of rape myths, the inequality between men and women, and the need to express their dominance made the rape appear justified to the assailants. Many began raping when they were young teenagers for entertainment, reflecting the notion that rape is a pastime for young men and boys.\n"
] |
why don't vending machines keep their change topped up from the money people put in?
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Filtering a coin box and setting it up so that it can provide change is possible, but requires a more expensive model of vending machine. Most vendors are willing to pay for a cheaper model because guess what, people are still going to use it.
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[
"Vendors have a wide variety of machines to choose from. The selection of a machine is important because it can affect sales, time spent servicing the machine, willingness of locations to allow placement of the machine, and a variety of other factors affecting overall profits. Like a car, once a vending machine is placed in service, its resale value drops dramatically. This is especially true for machines that were overpriced to begin with.\n",
"Often, they can have the existing vending machines removed and get permission to install their own machines by promising to lower prices, stock the machine with the manager's favorite candies, or provide better service (e.g. servicing the machine the same day if a coin jam or bill validator becomes jammed).\n",
"Demand for new machines has declined due to increased use of credit cards and the conversion of casinos to coinless Ticket-In, Ticket-Out technology for their slot machines, but some industries still require machines to wrap and sort the large volume of coins that are taken in.\n",
"The newspaper vending machines began to lose popularity as many newspapers switched to online distribution, and as newspaper prices rose; as most vending machines are completely mechanical with no moving parts, few of them have paper currency validators which need some kind of electrical power to work, requiring multiple quarters or dollar coins to be inserted. This is especially true for Sunday newspapers (for example, the Sunday \"New York Times\" costing $6 nationally and requiring 24 quarters in a vending machine), which see machines go unfilled by some papers due to the bulk of those editions reducing the number of copies that can possibly be sold. By 2009, various artists and inventors had begun working on re-purposing the boxes.\n",
"Operation of bulk vending equipment is usually fairly straightforward for the consumer, involving placing the appropriate coin or coins in the machine and turning a knob or pulling a lever. If candy in a machine is low, however, and it appears unevenly distributed, the customer may wish to rock or whack the machine in order to knock some candy into the candy wheel, which is located in the bottom of the canister in the center. Depending on the design of the machine, though – which usually involves a wheel making a one-third turn with every vend – it may already be too late to ensure that the next vend bears fruit. A distinguishing feature of bulk vending is that the items are dispensed at random, so it is usually impossible to choose which item comes out of the machine next. A child trying to get a complete set of baseball cards, for instance, may end up with several duplicates; hence, the introduction of \"trading cards\" and similarly themed products, with the idea that consumers will trade the duplicates with one another.\n",
"For operators, soda/snack machines have the advantage that many locations recognize the need for such machines. Many locations will, in fact, take the initiative to contact a vending company to request installation of a machine. Moreover, companies recognize the difficulty in moving these machines and are less likely to request removal, unless the operator does a poor job of servicing the machine. Almost all soda and snack machines have vend counters that track how many items are sold, making it difficult for an employee to steal money. The machines themselves, being large and heavy, are difficult to steal without drawing attention, compared to most bulk vending machines. \n",
"A change machine is a vending machine that accepts large denominations of currency and returns an equal amount of currency in smaller bills or coins. Typically these machines are used to provide coins in exchange for paper currency, in which case they are also often known as bill changers.\n"
] |
What did ancient teenagers do for fun?
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You mean a 'really' ancient civilisation such as the Greeks or the Egyptians, or will a more recent example do?
Roman teenagers from the 17th/18th/early-19th centuries grew up in the street and the society they lived in was rife with violence. Every *rione* (ward) of the city usually had a long-standing rivalry with another, and these neighbourhoods' identities were very strong; for example, the people from Trastevere despised Monti, the *monticiani* hated Trastevere with a passion, everbody hated the Ghetto and so on.
Thus many teenagers and their friends often formed what we'd call neighbourhood gangs, but - and this is an important point - there was no extorsion or racketeering going on: these hot-headed youths spent their days fighting the other youngsters from different neighbourhoods. These 'battles' often took place in the Roman Forum and were known as *battaglie a rocci* - stone fights, whose ammuniton was provided by the nearby ruins. Knife, sword (more precisely the *saracca*, a type of sabre) and even slingshot duels were also extremely common among young people, to the point that hospitals regularly received people with related wounds... especially during or after the Carnevale, as recalled by father Bresciani in his *Edmondo, o dei costumi del popolo romano*; an astounding number of youngsters died because of such forms of 'entertainment'.
Hostarias, or pubs, were the quintessential meeting place for your average Roman and were also the kind of place in which brawls were much too common; these youngsters, but also their older counterparts, lived a honour-based lifestyle in which even the minor offences had to be 'settled' - you're looking at someone the wrong way? Snickering at that guy a table over? Then you're looking for *rogna*, or trouble. As mentioned earlier, Jews were also made the object of such 'innocuous' pastimes... when outside the Ghetto, they had to wear a yellow ribbon on their hats and were easily recognisable: many a youngster took one of them during the Carnevale and [made him/her roll down the Capitoline Hill inside a barrel](_URL_0_). Other forms of 'entertainment' during such a festivity was the *corsa dei barberi*, during which wild horses were made to run through the via del Corso and contestants had to stop them with their bare hands. Perhaps unsurprisignly, too many young people died this way.
Card and dice games were *extremely* popular, and more often than not source of disputes... many of which ended up badly for the losing party. Favourite games were the *morra*, *faraone*, and the like but itinerant puppet theatres, the most famous of which belonged to the vitriolic Ghetanaccio, were popular as well; these often narrated the histories of fol poems such as the Meo Patacca. Finally, attending public execution (which were particulary cruel back then) was a popular pastime for both young and old people; *mazzolature* - during which the prisoner's head was smashed on a stone pedestal with the help of a hammer - quarterings and decapitations were also an occasion for social gathering exactly the same way a market or the hostaria were.
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[
"In Ancient Iran, youths under 24 years of age received thorough training in the sport of their time which included miming, horsemanship, polo, dart throwing, wrestling, boxing, archery, and fencing. They were taught under conditions of severe hardship so that when the need arose they could endure the adverse conditions of war such as hunger, thirst, fatigue, heat, cold, etc.\n",
"Relationships between adults and youths, both male and female, were practiced historically dating back to at least antiquity, when they were reported among a number of cultures, among which the Celtic, the Persian and the Greek. The best documented, and perhaps the most formalized, the Greek tradition has become emblematic of erotic relations between men and adolescent boys, known as pederasty.\n",
"The rite of passage undergone by Greek youths in the tribal prehistory of Greece evolved into the commonly known form of Greek pederasty after the rise of the city-state, or \"polis\". Greek boys no longer left the confines of the community, but rather paired up with older men within the confines of the city. These men, like their earlier counterparts, played an educational and instructive role in the lives of their young companions; likewise, just as in earlier times, they shared a sexual relationship with their boys. Penetrative sex, however, was seen as demeaning for the passive partner, and outside the socially accepted norm. In ancient Greece, sex was generally understood in terms of penetration, pleasure, and dominance, rather than a matter of the sexes of the participants. For this reason, pederasty was not considered to be a homosexual act, given that the ‘man’ would be taking on a dominant role, and his disciple would be taking on a passive one. When intercourse occurred between two people of the same gender, it still wasn't entirely regarded as a homosexual union, given that one partner would have to take on a passive role, and would therefore no longer be considered a ‘man’ in terms of the sexual union.\n",
"In certain states in Ancient Greece, such as Sparta and Crete, adolescent boys were expected to enter into a mentoring relationship with an adult man, in which they would be taught skills pertaining to adult life, such as hunting, martial arts and fine arts.\n",
"It was a norm in Ancient Greece for athletes to exercise and compete in the nude. In ancient Sparta, the Gymnopaedia was a yearly celebration during which naked youths displayed their athletic and martial skills through the medium of dancing. In antiquity even before the Classical era, e.g. on Minoan Crete, athletic exercise played an important part in daily life.\n",
"The youth of Rome had several forms of athletic play and exercise, such as jumping, wrestling, boxing, and racing. In the countryside, pastimes for the wealthy also included fishing and hunting. The Romans also had several forms of ball playing, including one resembling handball. Dice games, board games, and gamble games were popular pastimes. Women did not take part in these activities. For the wealthy, dinner parties presented an opportunity for entertainment, sometimes featuring music, dancing, and poetry readings. Plebeians sometimes enjoyed similar parties through clubs or associations, but for most Romans, recreational dining usually meant patronizing taverns. Children entertained themselves with toys and such games as leapfrog.\n",
"The Oldest Man is a strong example of slapstick comedy and clown acting, as the character typically performs exaggerated physical stunts and often injures himself comically in the process. For example, playing the grandfather character to Marion, Conway takes a drastically slow tumble down the stairs in one \"As the Stomach Turns\" sketch, aired Oct. 20, 1976, or in “The Oldest Torturer” sketch, aired Dec. 6, 1975, he slowly burns himself with a hot iron.\n"
] |
why do egg-whites foam when we whisk them and do not when there is just a very tiny amount of egg yolk in it?
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The foam form the whites is formed by proteins from the protein-rich egg-white. The yolk contains fats that destroy the protein foam (also called an emulsion). You can try this by mixing in a tiny amount of cooking oil into the egg-whites: it will have the same lack-of-foam effect as a tiny amount of yolk.
|
[
"The physical stress of beating egg whites can create a foam. Two types of physical stress are caused by beating them with a whisk, the first of which occurs as the whisk drags the liquid through itself, creating a force that unfolds the protein molecules. This process is called denaturation. The second stress comes from the mixing of air into the whites, which causes the proteins to come out of their natural state. These denatured proteins gather together where the air and water meet and create multiple bonds with the other unraveled proteins, and thus become a foam, holding the incorporated air in place, because the proteins consist of amino acids; some are hydrophilic (attracted to water) and some are hydrophobic (repelled by water). This process is called coagulation.\n",
"Typically an egg is poached just to the point where the white is no longer runny and the yolk is beginning to harden around the edges. Some people say creating a whirlpool helps with poaching eggs because it helps the egg stay together, wrapping the white around the yolk.\n",
"Similar to whipping egg whites, foaming is reduced in the presence of lipid contamination (grease, egg yolk, etc.). Foam depends on the ability of the surfactant (saponins in soapberries, denatured proteins in egg whites) molecules to bind with each other and create a hydrophobic interaction at the interface. When lipids are present, they interfere with this interaction and reduce the viscoelasticity of the foam.\n",
"Egg white proteins have many uses in baking, one of which is the ability to create and maintain a foam. Whipping incorporates air throughout the egg whites, as well as denaturing or unfolding the proteins to create thinner protein molecules. Overrun, similar to lightness, describes the amount of air pushed into the foam. In terms of an angel food cake, overrun is the increase in volume from the original volume caused by the inclusion of air. The overrun of an egg white foam ranges from 500 to 800%. This means that whipping 100 mL of egg whites would result in 500 mL - 800 mL of air incorporated into the foam. During whipping, protein adsorption allows for rapid foam formation. Adsorption is the ability to spontaneously form a very thin layer on a surface. The denatured proteins move to the air/water interface to create the cell walls of the air bubbles. Cell wall formation occurs when the denatured proteins aggregate, forming an extremely thin network or film. Many interactions between the proteins and the interface are possible, including hydrogen bonding, electrostatic interactions, disulfate bonds, and Van der Waals interactions. A cake made with egg yolks would not be as light and airy because they have a lower foaming ability than egg whites.\n",
"Eggshell color is caused by pigment deposition during egg formation in the oviduct and may vary according to species and breed, from the more common white or brown to pink or speckled blue-green. Generally, chicken breeds with white ear lobes lay white eggs, whereas chickens with red ear lobes lay brown eggs. Although there is no significant link between shell color and nutritional value, often there is a cultural preference for one color over another (see 'Color of eggshell', below). Brown eggs have significantly higher incidence of blood spots due to candling being less effective.\n",
"When beating egg whites, they are classified in three stages according to the peaks they form when the beater is lifted: soft, firm, and stiff peaks. Overbeaten eggs take on a dry appearance, and eventually collapse. Egg whites do not beat up correctly if they are exposed to any form of fat, such as cooking oils or the fats contained in egg yolk.\n",
"BULLET::::- If so, that may explain why the patches from which monotremes secrete milk are hairy. It is easier to spread moisture and other substances over the egg from a broad, hairy area than from a small, bare nipple.\n"
] |
how do we not run out of telephone numbers?
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How did you get that figure? Did you do 10 factorial or something? Isn't it as simple as 10^10?
Edit: you did do 10!, that's for a combination of things that exclude what's already been used and can't be used again. So a line of x amount of people has x! Combinations, you can use it that way because there can't be 2 tims, but phone numbers can have 2 7s
|
[
"This is the process whereby a telephone subscriber whose telephone line is maintained by one company, usually a former monopoly provider (e.g. BT), can choose to have some of their calls automatically routed across a different telephone company's network (e.g. Talk Talk) without needing to enter a special code or special equipment.\n",
"In some parts of the United States, especially northeastern states such as Pennsylvania served by Verizon Communications, the ten-digit number must be dialed. If the call is not local, the call fails unless the dialed number is preceded by digit 1. Thus:\n",
"Currently, these numbers are mostly used as the termination points for non-geographic numbers, and by some automated systems such as alarms. As such they are not usually meant to be directly dialled. These numbers have been problematic as some mobile phone operators in the UK do not allow access to these ranges, and there may also be difficulty accessing these numbers from outside the UK.\n",
"A telephone number serves as an address for switching telephone calls using a system of destination code routing. Telephone numbers are entered or dialed by a calling party on the originating telephone set, which transmits the sequence of digits in the process of signaling to a telephone exchange. The exchange completes the call either to another locally connected subscriber or via the PSTN to the called party. Telephone numbers are assigned within the framework of a national or regional telephone numbering plan to subscribers by telephone service operators, which may be commercial entities, state-controlled administrations, or other telecommunication industry associations.\n",
"A telephone number is a sequence of digits assigned to a fixed-line telephone subscriber station connected to a telephone line or to a wireless electronic telephony device, such as a radio telephone or a mobile telephone, or to other devices for data transmission via the public switched telephone network (PSTN) or other public and private networks.\n",
"In small countries or areas, the full telephone number is used for all calls, even in the same area. This has traditionally been the case in small countries and territories where area codes have not been required. However, there has been a trend in many countries towards making all numbers a standard length, and incorporating the area code into the subscriber's number. This usually makes the use of a trunk code obsolete.\n",
"Single number means that the mobile phone and the desk phone share an extension number. So only one phone number need be given out to receive calls on either a mobile or desk phone. But the cell phone likely still has its own number, it’s just that one need not give it out to anyone. To make business calls from a cell phone, one dials an access number at the office, gets a new dial tone, and then dials the destination number. This allows taking advantage of corporate least-cost-routing, and shows the office number on the caller ID display of the called person.\n"
] |
What memorials/monuments, if any, has the USA donated to other countries that is not about the US in anyway.
|
I think that the Marshall Plan was a pretty swell thing for the U.S. to do. It's not a commemorative statue, but you could probably find a list of many public projects that were completed as a result of the money. Almost all of the money was given in the form of grants and European countries, to my knowledge, were only asked to pay for the administrative costs of the program. We spent $13 billion on Europe, which was about 5 percent of our 1948 GDP. That's a *lot* of money in grants.
Edit: Just for further comparison, in 2012, the equivalent project would cost around $754 billion, as a percent of GDP.
|
[
"American War Memorials Overseas (AWMO) was founded in 2008 and is a non-profit corporation working to document, promote, and preserve non-government supported War Memorials honoring Americans outside of the United States. American War Memorials Overseas is a 501(c)(3) nonprofit corporation and as such is entirely dependent on donated funds.\n",
"The U.S. federal government, via the American Battle Monuments Commission, cares for 24 overseas cemeteries and 25 memorials. They have neither the authority nor the resources to care for thousands of other sites honoring Americans worldwide.\n",
"We still do not have a national memorial in Washington, D.C. to honor the Americans who sacrificed with their lives during World War I. On this eve of Veterans Day, I call upon the American people and the world to help me in asking our elected officials to pass the law for a memorial to World War I in our nation's capital. These are difficult times, and we are not asking for anything elaborate. What is fitting and right is a memorial that can take its place among those commemorating the other great conflicts of the past century. On this 92nd anniversary of the armistice, it is time to move forward with honor, gratitude, and resolve.\n",
"Another memorial to the US servicemen was unveiled in Washington, D.C., on 14 June 2006, at the National World War II Memorial. After the unveiling, it was moved temporarily to the Embassy of Australia in Washington, D.C. Because embassies are considered foreign soil, the Bakers Creek Memorial Association (USA) petitioned American lawmakers to relocate the memorial. After several years of negotiation, a dedication ceremony took place on 11 June 2009 at the Selfridge Gate entrance to Arlington National Cemetery on Fort Myer, Virginia.\n",
"The area of ground on which the memorial is situated was given as a gift to the United States of America by the people of The United Kingdom. (Though property ownership was transferred to the federal government of the United States, the area remains under the sovereignty of the United Kingdom.) It is maintained by the Kennedy Memorial Trust, which also sponsors educational scholarships for British students to attend university in the United States.\n",
"On September 21, 2015, United States Senator Moran of Kansas introduced a bill to the United States Congress to designate the memorial as the \"National Memorial to Fallen Educators\". Should the bill pass by both the U.S. House of Representatives and Senate, the memorial would then be signed by the President of the United States, and the memorial would not become a part of the National Park Service and no federal funds would be used.\n",
"On September 21, 2015, United States Senator Moran of Kansas introduced a bill to the United States Congress to designate the memorial as the \"National Memorial to Fallen Educators\". Should the bill pass by both the U.S. House of Representatives and Senate, the memorial would then need to be signed by the President of the United States. The memorial would not become a part of the National Park Service, nor would it receive Federal funding.\n"
] |
What exactly was the Battle of Actium?
|
Not to discourage any further answers but while you wait you'll probably enjoy these older posts:
[What was Mark Antony's intention when he gave Rome's lands to Egypt in 34BC? And why did it take Rome two years to start a war against him?](_URL_6_)
[What were some of the rumors about Cleopatra during the civil war between Octavian and Mark Anthony?](_URL_3_)
[What positive things did Cleopatra do in her reign?](_URL_4_)
[Did Augustus order the death of Caesarion or wanted to bring him first to the triumph like he pretended with Cleopatra, Caesarion's mother?](_URL_2_)
[What happened to the Ptolemaic Egyptian bureaucracy after the Romans took over?](_URL_1_)
[Were the trappings of the office of pharoah maintained in any way in Roman Egypt?](_URL_5_)
[What was the religion of Egypt like after Cleopatra and before Christianity?](_URL_0_)
By /u/cleopatra_philopater
|
[
"The Battle of Actium was the decisive confrontation of the Final War of the Roman Republic, a naval engagement between Octavian and the combined forces of Mark Antony and Cleopatra on 2 September 31 BC, on the Ionian Sea near the promontory of Actium, in the Roman province of Epirus Vetus in Greece. Octavian's fleet was commanded by Marcus Vipsanius Agrippa, while Antony's fleet was supported by the power of Queen Cleopatra of Ptolemaic Egypt.\n",
"The Battle of Asculum took place in 279 BC between the Roman Republic under the command of the consuls Publius Decius Mus and Publius Sulpicius Saverrio and the forces of king Pyrrhus of Epirus. The battle took place during the Pyrrhic War, after the Battle of Heraclea of 280 BC, which was the first battle of the war. There exist accounts of this battle by three ancient historians: Dionysius of Halicarnassus, Plutarch and Cassius Dio. Asculum was in Lucanian territory, In southern Italy.\n",
"The Battle of Dyrrachium (or Dyrrhachium) on 10 July 48 BC was a battle during Caesar's Civil War that took place near the city of Dyrrachium (in what is now Albania). It was fought between Julius Caesar and an army led by Gnaeus Pompey who had the backing of the majority of the Roman Senate. The battle was a victory for Pompey, albeit not a decisive one. The battle preceded the Battle of Pharsalus which was the decisive battle of the Civil War.\n",
"The Battle of Philippi was the final battle in the Wars of the Second Triumvirate between the forces of Mark Antony and Octavian (of the Second Triumvirate) and the leaders of Julius Caesar's assassination, Marcus Junius Brutus and Gaius Cassius Longinus in 42 BC, at Philippi in Macedonia. The Second Triumvirate declared this civil war ostensibly to avenge Julius Caesar's assassination in 44 BC, but the underlying cause was a long-brewing conflict between the so-called Optimates and the so-called Populares.\n",
"The Battle of Canusium was a three-day engagement between the forces of Rome and Carthage. It took place in Apulia during the spring of 209 BC, the tenth year of the Second Punic War. A larger Roman offensive, of which it was a part, aimed to subjugate and to punish cities and tribes that had abandoned the alliance with Rome after the Battle of Cannae, and to narrow the base of the Carthaginian leader, Hannibal, in southern Italy.\n",
"The Battle of Tifernum (297 BC) was an important battle of the Third Samnite War, fought in 297 BC near Città di Castello (next to Perugia, in what is now central Italy), in which the Romans overcame a determined Samnite army. The result would lead to the decisive Battle of Sentinum, which granted Rome the domination of central Italy.\n",
"The Battle of Asculum was fought in 89 BC during the Social War between Rome and its former Italian allies. The Romans were led by C. Pompeius Strabo, and were victorious over the rebels. The future Consul Publius Ventidius was said to have been captured as a youth at this battle and displayed in a Triumph at Rome.\n"
] |
seeing as video/picture quality is constantly increasing (1080p, 4k etc..), is there a limit to the quality that the human eye can notice a difference?
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Theres alot of conversation about this actually...
You really need to focus on DPI, since 1080p is very different on a 20" tv vs an 80".
But then it matters how far away it is, and how good your vision is...
Some would say we already eclipsed that limit with 1080p tvs at normal viewing distances. Yet... its trivial for a person to identify a 4k vs 1080p tv. Could they be seeing other advantages? better color? better source content? or is it something more than just how many rods and cones we have in our eyeball?
|
[
"However, in any situation where standard-definition video cameras are used, the quality is going to be poor because the maximum pixel resolution of the image chips in most of these devices is 320,000 pixels (analogue quality is measured in TV lines but the results are the same); they generally capture horizontal and vertical fields of lines and blend them together to make a single frame; the maximum frame rate is normally 30 frames per second.\n",
"The human visual system has a limited ability to discern improvements in resolution when picture elements are already small enough or distant enough from the viewer. At some home-viewing distances and current TV sizes, HD resolution is near the limits of resolution for the eye and increasing resolution to 4K has little perceptual impact, if consumers are beyond the critical distance (Lechner distance) to appreciate the differences in pixel count between 4K and HD. One exception to note is that even if resolution surpasses the resolving ability of the human eye, there is still an improvement in the way the image appears due to higher resolutions reducing spatial aliasing.\n",
"However, bandwidth benefits only apply to an analog or \"uncompressed\" digital video signal. With digital video compression, as used in all current digital TV standards, interlacing introduces additional inefficiencies. EBU has performed tests that show that the bandwidth savings of interlaced video over progressive video is minimal, even with twice the frame rate. I.e., 1080p50 signal produces roughly the same bit rate as 1080i50 (aka 1080i/25) signal, and 1080p50 actually requires less bandwidth to be perceived as subjectively better than its 1080i/25 (1080i50) equivalent when encoding a \"sports-type\" scene.\n",
"A 1998 Sun Microsystems paper on the limits of human vision and video display systems uses a different constraint value of approximately ½ an arc minute (or 30 arc seconds), when estimating the saturation point for the human visual system. With 30 arc seconds as the constraint, the view angle necessary to see all the detail provided by an HDTV with a 1080p resolution drops to approximately 16.1 degrees. Furthermore, several academic articles have challenged the notion that 1 arcminute of resolution is the typical resolving power of the human eye, suggesting that on average, we can resolve detail smaller than that. Also, there is the issue of vernier acuity, which is the eye's ability to detect an offset between 2 lines and stereoacuity, which is the ability to discriminate depth by the use of both eyes. Vernier acuity and stereoacuity are cited as being detected with only a 2–4 arc second degree of separation. Ultimately all of the various types of acuity play a part in how we see things and more importantly, how we perceive what we are witnessing. The complexities of the human visual system and the relationship between different types of acuity are not yet fully understood. Thus, depending on which human visual system constraints are applied, viewing angles calculations will vary to some degree, especially when technological constraints are factored in.\n",
"Because of its 480x480 resolution, SVCD picture quality is more than double that of VCD. On the downside, this increase in picture resolution sacrifices video length capacity by over 50%. Because of this, titles released on SVCD had to come on twice the number of discs.\n",
"Just as standard definition video with a high contrast MTF is only possible with oversampling, so HD television with full theoretical sharpness is only possible by starting with a camera that has a significantly higher resolution, followed by digitally filtering. With movies now being shot in 4k and even 8k video for the cinema, we can expect to see the best pictures on HDTV only from movies or material shot at the higher standard. However much we raise the number of pixels used in cameras, this will always remain true in absence of a perfect optical spatial filter. Similarly, a 5-megapixel image obtained from a 5-megapixel still camera can never be sharper than a 5-megapixel image obtained after down-conversion from an equal quality 10-megapixel still camera. Because of the problem of maintaining a high contrast MTF, broadcasters like the BBC did for a long time consider maintaining standard definition television, but improving its quality by shooting and viewing with many more pixels (though as previously mentioned, such a system, though impressive, does ultimately lack the very fine detail which, though attenuated, enhances the effect of true HD viewing).\n",
"Resolution in pixels is not the only measure of image quality. A larger sensor with the same number of pixels generally produces a better image than a smaller one. One of the most important differences is an improvement in image noise. This is one of the advantages of digital SLR (single-lens reflex) cameras, which have larger sensors than simpler cameras (so-called point and shoot cameras) of the same resolution.\n"
] |
how do studios get to film in places as dense as new york without interrupting business and traffic, while also not being interrupted during filming?
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I've got 10+ years working in the industry, my father was a camera operator and my grandfather was a Director/Producer of stage, TV and Film.
The studio, via the production coordinator/manager, makes an agreement with the city, and they provide Police assistance to close down the area the crew wants to film in. Sometimes they simply use squad cars to block off the area, other times they use small, lightweight barriers, it depends a bit on how large and busy an area they need to close off. The city gets a huge fee to cover their costs (and a little extra) and businesses in the closed area are given a compensation for lost income.
The city usually has stipulations on timing, and they generally try to avoid letting crews use any tremendously busy areas during normal business hours, especially in places like Times Square and the corner of Hollywood and Highland, which are huge thoroughfares for traffic and also cater to huge numbers of tourists who will be blocked from spending their money while filming is ongoing. However, this isn't a non-negotiable policy, if there's enough money on the table and the blockage will only be for a few hours, it can happen. Because of the cost and logistics, they usually try to expedite the process and be in and out as quickly as possible.
It's also worth noting that soundstages and backlots around the world have a nice collection of extremely convincing recreations of certain areas, so there are many cases where they simply use a 2nd unit crew to get exterior footage of the actual area, and then film the rest of the scene on a lot or in a stage. Also, green screens - see the Times Square footage in the 2nd Spiderman, per another user's response.
|
[
"While filming on busy New York City streets presents countless challenges, the unit has, over the years, developed a strong working relationship with the film industry. The unit makes an effort to ensure that New York City remains a popular location for filming.\n",
"The New York City Transit Authority denied permission to film on its property, including background shots, but the filmmakers shot them anyway. In order to get the necessary footage, cinematographer Gerald Hirschfeld and his son rode the subway and surreptitiously shot the moving background with a camera hidden in a cardboard box. \n",
"When the film industry began shooting films in New England with frequency in the early 2000s, old warehouses and office buildings were used for filming due to a lack of infrastructure in the region, leading to several groups of developers coming forward with plans to build full service studios.\n",
"The film was shot on location in Nevada. It pioneered the use of Introvision, a system that allows actors to walk in and out of photographs instead of sets. It was used to create the headquarters for the private army. \"It's an absolutely phenomenal system,\" said the film's producer, Al Ruddy of Introvision. \"There's no way you can get the quality and the speed of delivery at this cost.\"\n",
"The studio zone itself, as well as the lack of motion picture production companies and experienced personnel outside the zone, made it expensive to film on location, since movie studios had to bring everything needed from Los Angeles. In turn, anyone who wanted to start a career in the entertainment industry had to move to Los Angeles to break into the studio zone.\n",
"The film's setting proved to be a potential problem for Carpenter, who needed to create a decaying, semidestroyed version of New York City on a shoe-string budget.The film's production designer Joe Alves and he rejected shooting on location in New York City because it would be too hard to make it look like a destroyed city. Carpenter suggested shooting on a movie back lot, but Alves nixed that idea \"because the texture of a real street is not like a back lot.\" They sent Barry Bernardi, their location manager (and associate producer), \"on a sort of all-expense-paid trip across the country looking for the worst city in America,\" producer Debra Hill remembers.\n",
"Filmmakers responded to the open access and additional services. According to HBO executive Bruce Richmond, \"Location shoots, especially in a city the scale of New York, have their complexities, so you always want an engaged mayor's office. That's exactly what we've seen with Mayor Bloomberg's team.\"\n"
] |
why do large amounts of flammable material in a small space explode (ex: gasoline can) when ignited instead of just lighting on fire and burning like wood
|
Burning causes things to expand, heat up and release gases. if its in an enclosed space such as a pipe, grenade casing, gas can, etc... then the pressure from these reactions builds up causing the big bada boom.
|
[
"When this mixture of fuel and air is ignited, especially in a confined space such as a warehouse or silo, a significant increase in pressure is created, often more than sufficient to demolish the structure. Even materials that are traditionally thought of as nonflammable (such as aluminum), or slow burning (such as wood), can produce a powerful explosion when finely divided, and can be ignited by even a small spark.\n",
"In fighting a fire at a directly vertical spewing wellhead, high explosives, such as dynamite were used to create a blast wave that pushes the burning fuel and local atmospheric oxygen away from the well. (This is a similar principle to blowing out a candle.) The flame is removed and the fuel can continue to spill out without igniting. Generally, explosives were placed within 55 gallon drums, the explosives surrounded by fire retardant chemicals, and then the drums are wrapped with insulating material with a horizontal crane being used to bring the drum as close to the burning area as possible.\n",
"Mixtures of dispersed combustible materials (such as gaseous or vaporised fuels, and some dusts) and air will burn only if the fuel concentration lies within well-defined lower and upper bounds determined experimentally, referred to as flammability limits or explosive limits. Combustion can range in violence from deflagration through detonation.\n",
"The properties of some ignitable liquids make them dangerous accelerants. Many ignitable liquids have high vapor pressures, low flash points and a relatively wide range between their upper and lower explosive limit. This allows ignitable liquids to ignite easily, and when mixed in a proper air-fuel ratio, readily explode. Many arsonists who use generous amounts of gasoline have been seriously burned or killed igniting their fire.\n",
"Highly concentrated sources of oxygen promote rapid combustion. Oxygen itself is not flammable, but the addition of concentrated oxygen to a fire greatly increases its intensity, and can aid the combustion of materials (such as metals) which are relatively inert under normal conditions. Fire and explosion hazards exist when concentrated oxidants and fuels are brought into close proximity; however, an ignition event, such as heat or a spark, is needed to trigger combustion. A well-known example of an accidental fire accelerated by pure oxygen occurred in the Apollo 1 spacecraft in January 1967 during a ground test; it killed all three astronauts. A similar accident killed Soviet cosmonaut Valentin Bondarenko in 1961.\n",
"In the case of a firebox explosion, these typically occur after a burner flameout. Oil fumes, natural gas, propane, coal, or any other fuel can build up inside the combustion chamber. This is especially of concern when the vessel is hot; the fuels will rapidly volatize due to the temperature. Once the lower explosive limit (LEL) is reached, any source of ignition will cause an explosion of the vapors.\n",
"The properties of some ignitable liquids make them dangerous fuels. Many ignitable liquids have high vapor pressures, low flash points and a relatively wide range between their upper and lower explosive limit. This allows ignitable liquids to ignite easily, and when mixed in a proper air-fuel ratio, readily explode. Many arsonists who use generous amounts of gasoline have been seriously burned or killed igniting their fire.\n"
] |
warm fronts
|
Warm air moves to an area where there is already cold air.
As the warm air moves into the new area, it gets pushed up on top of the cold air.
Unlike cold fronts, the weather at warm fronts tends to be stable. In other words, as the warm air rises and cools, it becomes dense enough that it's not going to continue rising and rising.
Because of this, warm fronts tend to have lots of "stratus" types of cloud, that means layers of cloud (rather than big, bumpy clouds), and a warm front would normally be associated with persistent drizzle and rain (whereas cold fronts create lumpy "cumulous" clouds, and are associated with heavy rain showers).
|
[
"A warm front is a density discontinuity located at the leading edge of a homogeneous warm air mass, and is typically located on the equator-facing edge of an isotherm gradient. Warm fronts lie within broader troughs of low pressure than cold fronts, and move more slowly than the cold fronts which usually follow because cold air is denser and less easy to remove from the Earth's surface. This also forces temperature differences across warm fronts to be broader in scale. \n",
"Warm fronts are at the leading edge of a homogeneous warm air mass, which is located on the equatorward edge of the gradient in isotherms, and lie within broader troughs of low pressure than cold fronts. A warm front moves more slowly than the cold front which usually follows because cold air is denser and harder to remove from the Earth's surface.\n",
"Warm fronts mark the position on the Earth's surface where a relatively warm body of air has displaced colder air. The temperature increase is located on the equatorward edge of the gradient in isotherms, and lies within broader low pressure troughs than is the case with cold fronts. Warm fronts move more slowly than do the cold fronts because cold air is denser, and harder to displace from the Earth's surface. This causes temperature differences across warm fronts to be broader in scale. The warm air mass overrides the cold air mass and temperature changes occur at higher altitudes before those at the surface. Clouds ahead of the warm front are mostly stratiform and rainfall gradually increases as the front approaches. Fog can also occur preceding a warm front passage. Clearing and warming is usually rapid after the passage of a warm front. If the warm air mass is unstable, mixing of the warm moist air will produce thunderstorms that are embedded among the stratiform clouds ahead of the front, and after frontal passage, thundershowers may continue. On weather maps, the surface location of a warm front is marked with a red line of half circles pointing in the direction of travel.\n",
"Warm fronts occur where warm air pushes out a previously extant cold air mass. The warm air overrides the cooler air and moves upward dud . Warm fronts are followed by extended periods of light rain and drizzle due to the fact that, after the warm air rises above the cooler air (which remains on the ground), it gradually cools due to the air's expansion while being lifted, which forms clouds and leads to precipitation.\n",
"A warm front is also defined as the transition zone where a warmer air mass is replacing a cooler air mass. Warm fronts generally move from southwest to northeast. If the warmer air originates over the ocean, it is not only warmer but also more moist than the air ahead of it.\n",
"A cold front's location is at the leading edge of the temperature drop-off, which in an isotherm analysis shows up as the leading edge of the isotherm gradient, and it normally lies within a sharp surface trough. Cold fronts can move up to twice as fast as warm fronts and produce sharper changes in weather, since cold air is denser than warm air and rapidly lifts the warm air as the cold air moves in. Cold fronts are typically accompanied by a narrow band of showers and thunderstorms. On a weather map, the surface position of the cold front is marked with the symbol of a blue line of triangles/spikes (pips) pointing in the direction of travel, at the leading edge of the cooler air mass.\n",
"Cold fronts form when a cooler air mass moves into an area of warmer air in the wake of a developing extratropical cyclone. The warmer air interacts with the cooler air mass along the boundary, and usually produces precipitation. Cold fronts often follow a warm front or squall line. Very commonly, cold fronts have a warm front ahead but with a perpendicular orientation. In areas where cold fronts catch up to the warm front, the occluded front develops. Occluded fronts have an area of warm air aloft. When such a feature forms poleward of an extratropical cyclone, it is known as a trowal, which is short for TRough Of Warm Air aLoft. A cold front is considered a warm front if it begins to retreat ahead of the next extratropical cyclone along the frontal boundary, and called a stationary front if it stalls.\n"
] |
How did Einstein 'discover' time-dilation?
|
It was pretty well established by then that light acts like a wave. Now any other wave that we know about needs a medium to propagate through: ocean waves need water, sound waves need air. It was natural to assume that light needed a medium too, which they called the 'ether', but every experimental attempt to prove its existence failed miserably. The consequence of it having no medium means that there is no preferred frame for light, which given this and Maxwell's equations, means that the speed of light is constant for any observer. (As opposed to, say, me throwing a ball on a train: if I'm on the train I see it moving slowly, if you're off the train, you see it moving at the speed of the train plus the speed of the ball. If it was a photon, we'd BOTH see it moving at 3x10^8 m/s... weird but true). Time dilation and length contraction both come out of the math when you start formalizing these postulates, as in the Lorentz Transformations. Hope that helps - feel free to ask for clarification, and I'll do my best =]
|
[
"Einstein subsequently (1907) suggested an experiment based on the measurement of the relative frequencies of light perceived as arriving from a light source in motion with respect to the observer, and he calculated the additional Doppler shift due to time dilation. This effect was later called \"transverse Doppler effect\" (TDE), since such experiments were initially imagined to be conducted at right angles with respect to the moving source, in order to avoid the influence of the longitudinal Doppler shift. Eventually, Herbert E. Ives and G. R. Stilwell (referring to time dilation as following from the theory of Lorentz and Larmor) gave up the idea of measuring this effect at right angles. They used rays in longitudinal direction and found a way to separate the much smaller TDE from the much bigger longitudinal Doppler effect. The experiment was performed in 1938 and it was reprised several times (see, e.g.). Similar experiments were conducted several times with increased precision, for example by Otting (1939), Mandelberg \"et al.\" (1962),\n",
"There is a great deal of observable evidence for time dilation in special relativity and gravitational time dilation in general relativity, for example in the famous and easy-to-replicate observation of atmospheric muon decay. The theory of relativity states that the speed of light is invariant for all observers in any frame of reference; that is, it is always the same. Time dilation is a direct consequence of the invariance of the speed of light. Time dilation may be regarded in a limited sense as \"time travel into the future\": a person may use time dilation so that a small amount of proper time passes for them, while a large amount of proper time passes elsewhere. This can be achieved by traveling at relativistic speeds or through the effects of gravity.\n",
"Albert Einstein's special theory of relativity (and, by extension, the general theory) predicts time dilation that could be interpreted as time travel. The theory states that, relative to a stationary observer, time appears to pass more slowly for faster-moving bodies: for example, a moving clock will appear to run slow; as a clock approaches the speed of light its hands will appear to nearly stop moving. The effects of this sort of time dilation are discussed further in the popular \"twin paradox\". These results are experimentally observable and affect the operation of GPS satellites and other high-tech systems used in daily life.\n",
"The transverse Doppler effect and consequently time dilation was directly observed for the first time in the Ives–Stilwell experiment (1938). In modern Ives-Stilwell experiments in heavy ion storage rings using saturated spectroscopy, the maximum measured deviation of time dilation from the relativistic prediction has been limited to ≤ 10. Other confirmations of time dilation include Mössbauer rotor experiments in which gamma rays were sent from the middle of a rotating disc to a receiver at the edge of the disc, so that the transverse Doppler effect can be evaluated by means of the Mössbauer effect. By measuring the lifetime of muons in the atmosphere and in particle accelerators, the time dilation of moving particles was also verified. On the other hand, the Hafele–Keating experiment confirmed the twin paradox, \"i.e.\" that a clock moving from A to B back to A is retarded with respect to the initial clock. However, in this experiment the effects of general relativity also play an essential role.\n",
"Time dilation by the Lorentz factor was predicted by several authors at the turn of the 20th century. Joseph Larmor (1897), at least for electrons orbiting a nucleus, wrote \"... individual electrons describe corresponding parts of their orbits in times shorter for the [rest] system in the ratio :formula_1\". Emil Cohn (1904) specifically related this formula to the rate of clocks. In the context of special relativity it was shown by Albert Einstein (1905) that this effect concerns the nature of time itself, and he was also the first to point out its reciprocity or symmetry. Subsequently, Hermann Minkowski (1907) introduced the concept of proper time which further clarified the meaning of time dilation.\n",
"On June 30, 1905 (published September 1905) Einstein published what is now called special relativity and gave a new derivation of the transformation, which was based only on the principle on relativity and the principle of the constancy of the speed of light. While Lorentz considered \"local time\" to be a mathematical stipulation device for explaining the Michelson-Morley experiment, Einstein showed that the coordinates given by the Lorentz transformation were in fact the inertial coordinates of relatively moving frames of reference. For quantities of first order in \"v/c\" this was also done by Poincaré in 1900, while Einstein derived the complete transformation by this method. Unlike Lorentz and Poincaré who still distinguished between real time in the aether and apparent time for moving observers, Einstein showed that the transformations concern the nature of space and time.\n",
"Einstein (1907a) proposed a method for detecting the transverse Doppler effect as a direct consequence of time dilation. And in fact, that effect was measured in 1938 by Herbert E. Ives and G. R. Stilwell (Ives–Stilwell experiment). And Lewis and Tolman (1909) described the reciprocity of time dilation by using two light clocks A and B, traveling with a certain relative velocity to each other. The clocks consist of two plane mirrors parallel to one another and to the line of motion. Between the mirrors a light signal is bouncing, and for the observer resting in the same reference frame as A, the period of clock A is the distance between the mirrors divided by the speed of light. But if the observer looks at clock B, he sees that within that clock the signal traces out a longer, angled path, thus clock B is slower than A. However, for the observer moving alongside with B the situation is completely in reverse: Clock B is faster and A is slower. Also Lorentz (1910–1912) discussed the reciprocity of time dilation and analyzed a clock \"paradox\", which apparently occurs as a consequence of the reciprocity of time dilation. Lorentz showed that there is no paradox if one considers that in one system only one clock is used, while in the other system two clocks are necessary, and the relativity of simultaneity is fully taken into account.\n"
] |
why does a weak am/fm radio signal result in a consistent static/fuzzy sound while a weak satellite radio signal results in intermittent high quality sound?
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The simple answer is that AM/FM is an analog signal, which you can "kind of" pick up. Think of analog as a scale of 100-0 with the quality increasing or decreasing as you move from the transmitter.
Satellite radio is a digital signal. Think 1 or 0. It's either there, or it's not. The same holds true for satellite TV, where in a severe storm your picture will be perfect right up until it cuts out into nothingness.
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[
"Reception of RF signals is sensitive to the size of obstruction in the path between the transmitter and the receiver. Generally speaking, if the size exceeds the wavelength the reception is interrupted. Since the wavelength is inversely proportional to frequency, it follows than that the higher frequency broadcast is more sensitive to objects between the transmitter and receiver. If the transmitter and the receiver were at the opposite sides of a hill, MW radio signals may be received, but UHF TV signals won’t be received at all. That’s why translators are mostly employed for VHF and UHF broadcasting (television and FM radio).\n",
"Random noise has a \"triangular\" spectral distribution in an FM system, with the effect that noise occurs predominantly at the highest audio frequencies within the baseband. This can be offset, to a limited extent, by boosting the high frequencies before transmission and reducing them by a corresponding amount in the receiver. Reducing the high audio frequencies in the receiver also reduces the high-frequency noise. These processes of boosting and then reducing certain frequencies are known as pre-emphasis and de-emphasis, respectively.\n",
"BULLET::::- Audio equipment associated with radio transmitters, particularly transceivers in two way radios, such as Citizens band, FRS, which have automatic gain control (AGC) or squelch noise control. Malfunctions in the AGC or squelch circuits, which have long time constants, can cause low frequency oscillation. Another possible cause, sometimes in combination with the first, is leakage of the strong radio frequency (RF) signal from the transmitter into the receiver audio sections, which can cause quenching oscillations. This is a RFI problem, caused by inadequate shielding or filtering to keep the RF out.\n",
"Very high frequency radio waves can be refracted by inversions, making it possible to hear FM radio or watch VHF low-band television broadcasts from long distances on foggy nights. The signal, which would normally be refracted up and away from the ground-based antenna, is instead refracted down towards the earth by the temperature-inversion boundary layer. This phenomenon is called tropospheric ducting. Along coast lines during Autumn and Spring, due to multiple stations being simultaneously present because of reduced propagation losses, many FM radio stations are plagued by severe signal degradation causing them to sound scrambled.\n",
"Frequency modulation generates high quality audio and greatly reduces the amount of noise on the channel when compared with amplitude modulation. Early broadcasters used amplitude modulation because it was easier to generate than frequency modulation and because the receivers were simpler to make. The electronics theory indicated that a frequency modulated signal would have infinite bandwidth; for an amplitude modulated signal, the bandwidth is approximately twice the highest modulating frequency.\n",
"The reason that preemphasis is needed is that the process of detecting a frequency-modulated signal in a receiver produces a noise spectrum that rises in frequency (a so-called \"triangular\" spectrum). Without preemphasis, the received audio would sound unacceptably noisy at high frequencies, especially under conditions of low carrier-to-noise ratio, i.e., during fringe reception conditions. Preemphasis increases the magnitude of the higher signal frequencies, thereby improving the signal-to-noise ratio. At the output of the discriminator in the FM receiver, a deemphasis network restores the original signal power distribution.\n",
"The service area from a VHF or UHF radio transmitter extends to just beyond the optical horizon, at which point signals start to rapidly reduce in strength. Viewers living in such a \"deep fringe\" reception area will notice that during certain conditions, weak signals normally masked by noise increase in signal strength to allow quality reception. Such conditions are related to the current state of the troposphere.\n"
] |
why are anarchists and nihilists put on the same political wing as socialist and communists?
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If you look at it economically, anarchism has strong ties to socialist/communist theory. Anarchists are pretty misunderstood, it's not all about no rules and complete chaos. Early anarchists believed that you should grow food, and whatever extra you had you should give to your neighbours for free, and vice versa. This idea is basically the opposite of capitalism, where you pretty much want to make as much money as you can off of your extra food. That is just one example of policy why it is on the left, rather than the right.
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[
"Some forms of anarcho-communism such as insurrectionary anarchism are strongly influenced by egoism and radical individualism, believing anarcho-communism is the best social system for the realisation of individual freedom. Hence, most anarcho-communists view anarcho-communism itself as a way of reconciling the opposition between the individual and society. Furthermore, post-left anarchists like Bob Black went as far as to argue that \"communism is the final fulfillment of individualism. [...] The apparent contradiction between individualism and communism rests on a misunderstanding of both. [...] Subjectivity is also objective: the individual really is subjective. It is nonsense to speak of \"emphatically prioritizing the social over the individual,\" [...]. You may as well speak of prioritizing the chicken over the egg. Anarchy is a \"method of individualization.\" It aims to combine the greatest individual development with the greatest communal unity\". Indeed, Max Baginski has argued that property and the free market are just other \"spooks\", what Stirner called to refer mere illusions, or ghosts in the mind, writing: \"Modern Communists are more individualistic than Stirner. To them, not merely religion, morality, family and State are spooks, but property also is no more than a spook, in whose name the individual is enslaved — and how enslaved! [...] Communism thus creates a basis for the liberty and Eigenheit of the individual. I am a Communist because I am an Individualist. Fully as heartily the Communists concur with Stirner when he puts the word take in place of demand — that leads to the dissolution of property, to expropriation. Individualism and Communism go hand in hand\". Peter Kropotkin argued that \"Communism is the one which guarantees the greatest amount of individual liberty — provided that the idea that begets the community be Liberty, Anarchy [...]. Communism guarantees economic freedom better than any other form of association, because it can guarantee wellbeing, even luxury, in return for a few hours of work instead of a day's work\". \"Dielo Truda\" similarly argued that \"[t]his other society will be libertarian communism, in which social solidarity and free individuality find their full expression, and in which these two ideas develop in perfect harmony\". In \"My Perspectives\" of \"Willful Disobedience\" (2: 12), it was argued as such: \"I see the dichotomies made between individualism and communism, individual revolt and class struggle, the struggle against human exploitation and the exploitation of nature as false dichotomies and feel that those who accept them are impoverishing their own critique and struggle\".\n",
"Some forms of anarcho-communism such as insurrectionary anarchism are egoist and strongly influenced by radical individualism, believing that anarchist communism does not require a communitarian nature at all. Most anarcho-communists view anarchist communism as a way of reconciling the opposition between the individual and society.\n",
"Some forms of anarchist communism such as insurrectionary anarchism are strongly influenced by egoism and radical individualism, believing anarcho-communism is the best social system for the realization of individual freedom. Most anarcho-communists view it as a way of reconciling the opposition between the individual and society.\n",
"The term left anarchism is sometimes used synonymously with libertarian socialism, left-libertarianism, or social anarchism. More traditional anarchists typically discourage the concept of left-wing theories of anarchism on grounds of redundancy and that it lends legitimacy to the notion that anarchism is compatible with capitalism or nationalism.\n",
"While many anarchists (especially those involved in the anti-globalization movement) continue to see themselves as a leftist movement, some thinkers and activists believe it is necessary to re-evaluate anarchism's relationship with the traditional left. Like many radical ideologies, most anarchist schools of thought are to some degree sectarian. There is often a difference of opinion within each school about how to react to, or interact with, other schools. Many anarchists draw from a wide range of political perspectives, such as the Zapatista Army of National Liberation, the Situationists, ultra-leftists, autonomist Marxism and various indigenous cultures.\n",
"Left-libertarians like social and individualist anarchists, libertarian Marxists and left-wing market anarchists argue in favor of libertarian socialist theories such as communism, mutualism and syndicalism. Daniel Guérin writes that \"anarchism is really a synonym for socialism. The anarchist is primarily a socialist whose aim is to abolish the exploitation of man by man. Anarchism is only one of the streams of socialist thought, that stream whose main components are concern for liberty and haste to abolish the State\".\n",
"Owing to the many anarchist schools of thought, anarchism can be divided into two or more categories, the most used being individualist anarchism vs. social anarchism. Other categorizations may include green anarchism and/or left and right anarchism. Terms like anarcho-socialism or socialist anarchism are rejected by most anarchists since they generally consider themselves socialists of the libertarian tradition and are seen as unnecessary and confusing when not used as synonymous with libertarian or stateless socialism vis-à-vis authoritarian or state socialism, but they are nevertheless used by anarcho-capitalist theorists and scholars who recognize anarcho-capitalism to differentiate between the two, or what is otherwise known as social anarchism. Since anarchism has been historically identified with the socialist and anti-capitalist movement, with the main divide being between anti-market anarchists who support some form of decentralised economic planning and pro-market anarchists who support free-market socialism, anarchists reject anarcho-capitalism as a form of individualist anarchism and reject categorizations such as left and right anarchism (anarcho-capitalism and national-anarchism), seeing anarchism as a libertarian socialist and radical left-wing or far-left ideology. Schools of thought like anarcha-feminism, anarcho-pacifism, anarcho-primitivism, anarcho-transhumanism and green anarchism, among others, can have different economic views and be either part of individualist anarchism or social anarchism.\n"
] |
How long does it take for plant cells to grow?
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This varies greatly from plant to plant, and it will vary based on the conditions. You also need to define 'grow' because cells can expand or divide to grow.
Plants that perform C4 photosynthesis (like grasses) tend to expand and divide rapidly under the right conditions, while plants that perform CAM photosynthesis (like cacti) will grow slower in an attempt to conserve water. There are [genes](_URL_0_) in some cultivars of rice that helps it keep itself above water when the paddy floods by rapidly growing to stay above water.
Many plants will halt growth if the conditions aren't right, and try to ride out the problem. Some plants will rapidly grow if they arn't getting enough sunlight in a sort of last-ditch effort not to die.
There really isn't a simple answer to your question, sorry.
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[
"Growing cells require synthesis of new nucleotides, membranes and protein components. These materials can be obtained from carbon metabolism (e.g. glucose metabolism) or from peripheral metabolism. The enhanced flux observed in abnormally growing cells is brought about by high glucose uptake.\n",
"Plants grow from fresh falling seeds. Although they germinate easily, it might take 10–15 years for them to grow into the flowering size. They flower between September and December, peaking in October (spring in New Zealand).\n",
"Tobacco BY-2 cells are nongreen, fast growing plant cells which can multiply their numbers up to 100-fold within one week in adequate culture medium and good culture conditions. This cultivar of tobacco is kept as a cell culture and more specifically as cell suspension culture (a specialized population of cells growing in liquid medium, they are raised by scientists in order to study a specific biological property of a plant cell). In cell suspension cultures, each of the cells is floating independently or at most only in short chains in a culture medium. Each of the cells has similar properties to the others. The model plant system is comparable to HeLa cells for human research. Because the organism is relatively simple and predictable it makes the study of biological processes easier, and can be an intermediate step towards understanding more complex organisms. They are used by plant physiologists and molecular biologists as a model organism.\n",
"The growth cycle is between (min-max) 90–170 days and under optimal conditions the cycle is about 120–150 days to pod maturity. Flowers appear 40–60 days after planting. 30 days after pollination the pod reaches maturity and during another 55 days the seeds fully develop.\n",
"The duration of the growth period is varying and conditional. The plant will continue to grow after flowering and will continue for as long as suitable temperatures and soil moisture endure. Seeds germinate and grow quickly, and some early-flowering types flower within 6 weeks. It spreads rapidly on appropriate soils, even in situations of heavy grazing pressure.\n",
"The growing cycle varies from 150 to 360 days, depending on the genotype, altitude and environmental conditions. Phenological phases are: emergence, first true leaf, formation of the raceme on the central stem, flowering, podding, pod ripening, and physiological maturity.\n",
"Also called the \"stretch\", this takes one day to two weeks. Most plants spend 10–14 days in this period after switching the light cycle to 12 hours of darkness. Plant development increases dramatically, with the plant doubling or more in size. (See reproductive development below.) Production of more branches and nodes occurs during this stage, as the structure for flowering grows. The plant starts to develop bracts/bracteoles where the branches meet the stem (nodes). Pre-flowering indicates the plant is ready to flower.\n"
] |
How thin is the surface of a bubble?
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Short Answer: Somewhere around 50-500 nano meters, depending on where you measure the bubble's thickness.
Long Answer: This can be measured using a very clever natural phenomenon, [thin-flim interference](_URL_0_).
So a bubble has two sides, the outside and the inside. Light coming from the sun hits the outside layer of the bubble, because light travels different speeds in a medium some of the light is reflected off of the outer layer of the bubble while most goes through it. This is a property of the index of refraction of a material, a small portion of light incident on a material with a different index of refraction that the lights original medium will reflect back.
The portion that goes through the outer layer then contacts the inner layer, again a change in the index of refraction causes some light to reflect back. So now we have two different rays of light that are exactly twice the thickness of a bubble out of phase from each other.
Now depending on the particular thickness of the bubble at that certain point the observer will likely see some color appear. This color occurs from what is called constructive and destructive interference. Destructive interference is when two waves that are 180 degrees out of phase come in contact with each other, this destroys the wave and no light is seen. Constructive interference is when two waves of the either 0 or 360 degrees out of phase come in contact with each other, this creates brighter light.
What we are seeing as color in the bubble is exactly a measurement of the thickness of that bubble. Say the color is purple and has a wavelength of 400nm. This means that the thickness of the bubble must be around 200nm, because the second beam of reflected light will constructively interfere if it travels and extra 400nm (in and back out) and destructively interfere if it travels any other distance.
Some discrepancies in the accuracy of the measurement occur when you include the light traveling at an angle into the bubble, but you get the idea.
This is also why thin layers of oil on water make rainbow colors. There are lots of uses of the phenomenon, such as infrared protective layering on the front of expensive camera lenses...
|
[
"A 1 mm bubble has negligible extra pressure. Yet when the diameter is ~3 µm, the bubble has an extra atmosphere inside than outside. When the bubble is only several hundred nanometers, the pressure inside can be several atmospheres. One should bear in mind that the surface tension in the numerator can be much smaller in the presence of surfactants or contaminants. The same calculation can be done for small oil droplets in water, where even in the presence of surfactants and a fairly low interfacial tension formula_4 = 5–10 mN/m, the pressure inside 100 nm diameter droplets can reach several atmospheres. Such nanoemulsions can be antibacterial because the large pressure inside the oil droplets can cause them to attach to bacteria and simply merge with them, swell them, and \"pop\" them.\n",
"The bubble chamber is similar to a cloud chamber, both in application and in basic principle. It is normally made by filling a large cylinder with a liquid heated to just below its boiling point. As particles enter the chamber, a piston suddenly decreases its pressure, and the liquid enters into a superheated, metastable phase. Charged particles create an ionization track, around which the liquid vaporizes, forming microscopic bubbles. Bubble density around a track is proportional to a particle's energy loss.\n",
"Bubble chambers are similar to cloud chambers, both in application and in basic principle. A chamber is normally made by filling a large cylinder with a liquid heated to just below its boiling point. As particles enter the chamber, a piston suddenly decreases its pressure, and the liquid enters into a superheated, metastable phase. Charged particles create an ionization track, around which the liquid vaporizes, forming microscopic bubbles. Bubble density around a track is proportional to a particle's energy loss. Bubbles grow in size as the chamber expands, until they are large enough to be seen or photographed. Several cameras are mounted around it, allowing a three-dimensional image of an event to be captured.\n",
"Bubble chambers are similar to cloud chambers, both in application and in basic principle. A chamber is normally made by filling a large cylinder with a liquid heated to just below its boiling point. As particles enter the chamber, a piston suddenly decreases its pressure, and the liquid enters into a superheated, metastable phase. Charged particles create an ionization track, around which the liquid vaporizes, forming microscopic bubbles. Bubble density around a track is proportional to a particle's energy loss. Bubbles grow in size as the chamber expands, until they are large enough to be seen or photographed. Several cameras are mounted around it, allowing a three-dimensional image of an event to be captured.\n",
"Bubble chambers are similar to cloud chambers, both in application and in basic principle. A chamber is normally made by filling a large cylinder with a liquid heated to just below its boiling point. As particles enter the chamber, a piston suddenly decreases its pressure, and the liquid enters into a superheated, metastable phase. Charged particles create an ionization track, around which the liquid vaporizes, forming microscopic bubbles. Bubble density around a track is proportional to a particle's energy loss. Bubbles grow in size as the chamber expands, until they are large enough to be seen or photographed. Several cameras are mounted around it, allowing a three-dimensional image of an event to be captured.\n",
"Bubble chambers are similar to cloud chambers, both in application and in basic principle. A chamber is normally made by filling a large cylinder with a liquid heated to just below its boiling point. As particles enter the chamber, a piston suddenly decreases its pressure, and the liquid enters into a superheated, metastable phase. Charged particles create an ionization track, around which the liquid vaporizes, forming microscopic bubbles. Bubble density around a track is proportional to a particle's energy loss. Bubbles grow in size as the chamber expands, until they are large enough to be seen or photographed. Several cameras are mounted around it, allowing a three-dimensional image of an event to be captured.\n",
"The bubbles can be as small as 6 millimeters (1/4 inch) in diameter, to as large as 26 millimeters (1 inch) or more, to provide added levels of shock absorption during transit. The most common bubble size is 1 centimeter. In addition to the degree of protection available from the size of the air bubbles in the plastic, the plastic material itself can offer some forms of protection for the object in question. For example, when shipping sensitive electronic parts and components, a type of bubble wrap is used that employs an anti-static plastic that dissipates static charge, thereby protecting the sensitive electronic chips from static which can damage them. One of the first widespread uses of bubble wrap was in 1960, shipping the new IBM 1401 computers to buyers. Most customers had never seen this packing material before.\n"
] |
Did Romans really have those feathered things on top of their helmets? If so, why?
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The "feathered thing" is called a crest and its usage depends on the time period:
In the days of the early republic, it was not common.
During the late republic (post 3rd century B.C.) it was very common among legionaries.
After the reforms by Augustus, only centurions were wearing crests.
In the later empire, they seem to be abandoned altogether.
|
[
"The origin of these very elaborate helmets is uncertain but appears not to have been Rome. Various origins have been suggested, including a theory that they came from Rome's eastern provinces. They were produced from the early 1st century AD through to the mid-3rd century. Although they are relatively light, they appear to have been worn in battle as well as for display purposes. One such helmet was found at the site of the Battle of the Teutoburg Forest, where three Roman legions were wiped out by Germans in 9 AD. It was perhaps worn by an officer or standard-bearer who intended its imposing appearance to intimidate his enemies on the battlefield.\n",
"Finds of Roman inspired Spangenhelm type helmets in Germanic chieftain graves, also tell us that the Germanics were in awe of Roman culture (generally speaking). We know that the Romans used this kind of helmet, amongst other sources from the Column of Trajan in Rome, on which Roman legionaries are depicted, wearing helmets. Stephen V. Granscay writes:\n",
"There is some limited evidence of such decorative motifs being used on actual helmets in the ancient world, but these may have functioned as ceremonial rather than functional objects. Attic helmets decorated with wings of sheet bronze were worn by the Samnites and other Italic peoples before their conquest by Rome. A number of such helmets have been excavated and can be seen in various museums.\n",
"The helmet was made of sheet bronze, and was of the Coolus style, a type used by both Gallic Warriors and Roman Legionaries, with a bowl shape and a flared beck to protect the back of the head and neck. This type of helmet was common on the continent, but is not commonly seen in Britain, though this may simply be due to the lack of finds from this era.\n",
"In the Roman Republic, the Montefortino helmet was the first stage in the development of the galea, derived from Celtic helmet designs. Similar types are to be found in Spain, Gaul, and into northern Italy. Surviving examples are generally found missing their cheek pieces (probably because they were made of a perishable material which has not survived, e.g., leather) though a pair of holes on each side of the helmet from which these plates would have hung tend to be clearly identifiable, and examples which do include cheek pieces show clearly how these holes were used. \n",
"Helmets like that which the Gevninge fragment once adorned served both as utilitarian equipment and as displays of status. Examples from Northern Europe during the Nordic Iron Age and Viking Age are rare. This may partly suggest a failure to survive a millennium underground or perhaps a failure to be recognised after excavation: the plainer Anglo-Saxon and Roman helmets from Shorwell and Burgh Castle were initially misidentified as pots. The extreme scarcity nevertheless suggests that they were never deposited in great numbers, and that they signified the importance of those wearing them. In the Anglo-Saxon poem \"Beowulf\", a story about kings and nobles that partly takes place in Denmark, helmets are mentioned often, and in ways that indicate their significance. The dying words of Beowulf, whose own pyre is stacked with helmets, are used to bestow a gold collar, byrnie, and gilded helmet to his follower Wiglaf.\n",
"Helmets made entirely of bronze were also used, while some of them had large cheek guards, probably stitched or riveted to the helmet, as well as an upper pierced knot to hold a crest. Small holes all around the cheek guards and the helmet's lower edge were used for the attachment of internal padding. Other types of bronze helmets were also used. During the late Mycenaean period, additional types were also used such as horned helmets made of strips of leather.\n"
] |
how is something scientifically proven to be a fact?
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Scientists don't tend to use the word "fact" for any generalized statement.
I dropped a ball from the top of a 100-meter building and I measured that it took 4.9 seconds to reach the ground. That's a *fact*. It's evidence consistent with the theory objects on Earth fall with an acceleration of approximately 9.8 meters per second squared.
The theory of gravity is our complete understanding of gravity based on all of the evidence we've collected. It takes into account things like wind resistance, so a feather falls more slowly than a brick. It takes into account the masses of the various objects involved, and it also takes into account Einstein's theory of relativity, which changes what happens pretty dramatically when the velocities involved are large.
The most important thing about a scientific theory, to me, is that it makes useful predictions. It says that given a certain situation, here's how to apply the theory to predict the outcome.
If it's right, it's a useful theory.
You can disbelieve the theory of gravity all you want, but that doesn't make it any less useful. If you can find a counterexample - some evidence that it's wrong under a certain set of circumstances, then the theory *must* change to incorporate that new evidence, if it can be reliably reproduced and the current theory is inconsistent with it.
In the case of 1+1=2, that's one of those things where as long as we all agree on the definitions of numbers and addition and equals, it's definitely true, but there are other scenarios where it's not true (like one cloud plus another cloud equals one larger cloud).
We don't talk about 1+1=2 just as an exercise, we talk about it because it's useful. We have problems to solve and math helps us get at the answer. If the answer we get is wrong then it's not very useful and then there'd be no point!
|
[
"In science, a \"fact\" is a repeatable careful observation or measurement (by experimentation or other means), also called empirical evidence. Facts are central to building scientific theories. Various forms of observation and measurement lead to fundamental questions about the scientific method, and the scope and validity of scientific reasoning.\n",
"Fact is often used by scientists to refer to experimental or empirical data or objective verifiable observations. \"Fact\" is also used in a wider sense to mean any theory for which there is overwhelming evidence.\n",
"While the phrase \"scientific proof\" is often used in the popular media, many scientists have argued that there is really no such thing. For example, Karl Popper once wrote that \"In the empirical sciences, which alone can furnish us with information about the world we live in, proofs do not occur, if we mean by 'proof' an argument which establishes once and for ever the truth of a theory.\" Albert Einstein said:\n",
"In scientific research evidence is accumulated through observations of phenomena that occur in the natural world, or which are created as experiments in a laboratory or other controlled conditions. Scientific evidence usually goes towards supporting or rejecting a hypothesis.\n",
"Scientific evidence consists of observations and experimental results that serve to support, refute, or modify a scientific hypothesis or theory, when collected and interpreted in accordance with the scientific method.\n",
"Scientific evidence is evidence which serves to either support or counter a scientific theory or hypothesis. Such evidence is expected to be empirical evidence and interpretation in accordance with scientific method. Standards for scientific evidence vary according to the field of inquiry, but the strength of scientific evidence is generally based on the results of statistical analysis and the strength of scientific controls.\n",
"Apart from the fundamental inquiry into the nature of scientific fact, there remain the practical and social considerations of how fact is investigated, established, and substantiated through the proper application of the scientific method. Scientific facts are generally believed independent of the observer: no matter who performs a scientific experiment, all observers agree on the outcome.\n"
] |
feces being a major source of harmful germs,how is it the lower intestine isn't chronically infected.
|
The vast majority of the bacteria in your colon are (mostly) harmless organisms that have evolved to live with us. The high populations of these bacteria tend to suppress the growth of other, harmful bacteria. Think of an apartment building with 100 units. 98 of them are already occupied by quiet residents. Even if the other 2 units are occupied by hooligans, they can't cause a lot of trouble and that trouble can't spread.
Now these bacteria aren't completely harmless. The very common E. coli bacteria causes infections ranging from mild (simple urinary tract infections) to life threatening (sepsis of the blood) if it gets somewhere it isn't supposed to be.
When we kill off the friendly bacteria, sometimes less savory ones take their place. A bowel infection known as C. difficile colitis is typically caused when antibiotics kill off the benign bacteria, leaving it behind. And some bacteria are just bad actors (like Salmonella or Shigella) and can cause infections even in healthy colons.
The colon itself as another poster noted is resistant to invasion from most gut microbes.
|
[
"An infarcted or dead intestinal segment is a serious medical problem because of the fact that intestines contain non-sterile contents within the lumen. Although the fecal content and high bacterial loads of the intestine are normally safely contained, progressive ischemia causes tissue breakdown and inevitably leads to bacteria spreading to the bloodstream. Untreated bowel infarction quickly leads to life-threatening infection and sepsis, and may be fatal. \n",
"Feces (or faeces) are the solid or semisolid remains of food that could not be digested in the small intestine. Bacteria in the large intestine further break down the material. Feces contain a relatively small amount of metabolic waste products such as bacterially altered bilirubin, and the dead epithelial cells from the lining of the gut.\n",
"Each gram of human feces contains approximately ~100 billion () bacteria. These bacteria may include species of pathogenic bacteria, such as \"Salmonella\" or \"Campylobacter\", associated with gastroenteritis. In addition, feces may contain pathogenic viruses, protozoa and parasites. Fecal material can enter the environment from many sources including waste water treatment plants, livestock or poultry manure, sanitary landfills, septic systems, sewage sludge, pets and wildlife. If sufficient quantities are ingested, fecal pathogens can cause disease. The variety and often low concentrations of pathogens in environmental waters makes them difficult to test for individually. Public agencies therefore use the presence of other more abundant and more easily detected fecal bacteria as indicators of the presence of fecal contamination.\n",
"There are numerous zoonotic pathogens shed in feline feces, such as Campylobacter and Salmonella spp; ascarids (e.g., Toxocara cati); hookworms (Ancylostoma spp); and the protozoan parasites Cryptosporidium spp, Giardia spp, and T gondii. Contaminated soil is an important source of infection for humans, herbivores, rodents, and birds and several studies suggest that pet feces contribute to bacterial loading of streams and coastal waters.\n",
"Uropathogenic \"E. coli\" from the gut is the cause of 80–85% of community-acquired urinary tract infections, with \"Staphylococcus saprophyticus\" being the cause in 5–10%. Rarely they may be due to viral or fungal infections. Healthcare-associated urinary tract infections (mostly related to urinary catheterization) involve a much broader range of pathogens including: \"E. coli\" (27%), \"Klebsiella\" (11%), \"Pseudomonas\" (11%), the fungal pathogen \"Candida albicans\" (9%), and \"Enterococcus\" (7%) among others. Urinary tract infections due to \"Staphylococcus aureus\" typically occur secondary to blood-borne infections. \"Chlamydia trachomatis\" and \"Mycoplasma genitalium\" can infect the urethra but not the bladder. These infections are usually classified as a urethritis rather than urinary tract infection.\n",
"Animal intestines contain a large population of gut flora. In humans, the four dominant phyla are Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. They are essential to digestion and are also affected by food that is consumed. Bacteria in the large intestine perform many important functions for humans, including breaking down and aiding in the absorption of fermentable fiber, stimulating cell growth, repressing the growth of harmful bacteria, training the immune system to respond only to pathogens, producing vitamin B, and defending against some infectious diseases. \"Probiotics\" refers to the idea of deliberately consuming live bacteria in an attempt to change the bacterial population in the large intestine, to the health benefit of the host human or animal. \"Prebiotic (nutrition)\" refers to the idea that consuming a bacterial energy source such as soluble fiber could support the population of health-beneficial bacteria in the large intestine. There is not yet a scientific consensus as to health benefits accruing from probiotics or prebiotics.\n",
"In the large intestine the passage of food is slower to enable fermentation by the gut flora to take place. Here water is absorbed and waste material stored as feces to be removed by defecation via the anal canal and anus.\n"
] |
What led to Sulla's retirement after being declared dictator for life?
|
The sources are particularly lousy for this: the wretched Appian on the one hand, and on the other Plutarch, more interested in the morbid details of his wasting disease than any politics. Scullard and Keaveney both argued that Sulla simply got tired and decided that he'd done enough to ensure a return to Republican form. Sulla retired to Cumae, into a Campania that he had essentially remade from the ground up in the aftermath of the ravages of the Social War. It was a pleasant place, to be sure, and I don't think there's anything wrong with believing that Sulla went there purely because he wanted to relax and indulge in the proclivities which he seemed to cultivate.
But I don't think that's right. I don't think Sulla was "done," and in fact the actions of Sulla in some ways provided a rough draft for how the *principes* would elevate themselves above the machinery of the Republic later, starting with his protege Pompey. Striking coins with his image while he still lived (a no-no in the *mos maiorum*), not to mention the giant equestrian statue of himself in the forum, both suggest Sulla had grand designs. He left off the dictatorship in 81 and held the consulship in 80, probably thinking he was secure enough in his position to do away with the more odious form of authority. His old rival Marius had held consecutive consulships in the past, and Sulla might have had something like that in mind in lieu of the dictatorship. If so, it never came to pass. I think the old madman was probably gently ushered out by the younger Sullani, Pompey in particular, and convinced to let others have a turn. He could have fought on, and there were plenty of Sullan veterans in Italia that he could have stirred up, but he seems to have just simply got too tired. I don't like modern claims that he was "forced out" or the like. Nobody ever forced Cornelius Sulla to do anything. It was most likely a combination of satisfaction with his life's work, fatigue and sickness, and the gentle, careful, but insistent advice of his young proteges.
Check out Jenkins' little article, "Sulla's Retirement," 1994. See also, for a modern and interesting look at Sulla, Santangelo's *Sulla, the Elites, and the Empire* Brill 2007.
|
[
"In 79 BC, Sulla resigned his dictatorship, re-established consular government and, after serving as consul in 80 BC, retired to private life. In a manner that the historian Suetonius thought arrogant, Julius Caesar would later mock Sulla for resigning the Dictatorship—\"Sulla did not know his political ABC's\". He died later in 78 BC and was accorded a state funeral. \n",
"Sulla resigned his dictatorship in 80 BC, was elected Consul one last time, and died in 78 BC. While he thought that he had firmly established aristocratic rule, his own career had illustrated the fatal weaknesses in the constitution. Ultimately, it was the army, and not the senate, which dictated the fortunes of the state.\n",
"Most authorities hold that a dictator could not be held to account for his actions after resigning his office, the prosecution of Marcus Furius Camillus for misappropriating the spoils of Veii being exceptional, as perhaps was that of Lucius Manlius Capitolinus in 362, which was dropped only because his son, Titus, threatened the life of the tribune who had undertaken the prosecution. However, some scholars suggest that the dictator was only immune from prosecution during his term of office, and could theoretically be called to answer charges of corruption.\n",
"With his reforms enacted, Sulla resigned as Dictator and retired to private life in 79 BC, dying the next year in 78 BC. Without his continued presence in Rome, Sulla's reforms were soon undone. Gnaeus Pompey Magnus and Marcus Licinius Crassus, two of Sulla's former lieutenants, were elected Consuls for the year 70 BC and quickly dismantled most of Sulla's constitution. While the Senate continued to be the primary organ of the Republican government with the magistrates subveriant to its will, the Tribunes regained the powers Sulla had stripped from the office.\n",
"Near the end of 81 BC, Sulla, true to his traditionalist sentiments, resigned his dictatorship, disbanded his legions and re-established normal consular government. He stood for office (with Metellus Pius) and won election as consul for the following year, 80 BC. He dismissed his lictors and walked unguarded in the Forum, offering to give account of his actions to any citizen. In a manner that the historian Suetonius thought arrogant, Julius Caesar would later mock Sulla for resigning the dictatorship.)\n",
"The \"imperium\" of the other magistrates was not vacated by the nomination of a dictator. They continued to perform the duties of their office, although subject to the dictator's authority, and continued in office until the expiration of their year, by which time the dictator had typically resigned. It is uncertain whether a dictator's \"imperium\" could extend beyond that of the consul by whom he was nominated; Mommsen believed that his \"imperium\" would cease together with that of the nominating magistrate, but others have suggested that it could continue beyond the end of the civil year; and in fact there are several examples in which a dictator appears to have entered a new year without any consuls at all, although some scholars doubt the authenticity of these \"dictator years\".\n",
"After various violent political turnovers while Sulla was on campaign in the East, he returned in 82 BC. After winning a second civil war and purging the Republic of thousands of his \"enemies\" (many of whom were targeted for their wealth), he forced the Assemblies to make him dictator for the settling of the constitution, with an indefinite term. Sulla attempted to concentrate political power into the Senate and the aristocratic assemblies, whilst trying to reduce the obstructive and legislative powers of the tribune and Plebeian council.\n"
] |
what are ghz and what do they mean when it comes to computer specs?
|
Hz is a measure of frequency- the number of times something happens per second. If something has a frequency of 3GHz, it means that it happens three billion times per second.
In the case of computers, that's the speed of its internal clock. A single operation in a computer can take multiple steps, and the clock speed tells you how long it gives each step to complete. A simple operation, like addition, might only take 1 clock tick to complete, while a more complex operation like trig functions, can take over 100.
Clock speed by itself doesn't mean much. You can use it to directly compare processors of the same series (so you can compare a 4th gen Core i5 with another 4th gen Core i5 processor), but different series of processors take different amounts of time to complete each operation, and a 3GHz processor that can finish a task in 100 clock cycles is faster than a 4GHz processor that takes 200 cycles to do the same work.
|
[
"BULLET::::- On August 31, 2011, in Austin, Texas, AMD achieved a Guinness World Record for the \"Highest frequency of a computer processor\": 8.429 GHz. The company ran an 8-core FX-8150 processor with only one active module (two cores), and cooled with liquid helium. The previous record was 8.308 GHz, with an Intel Celeron 352 (one core).\n",
"The processor line has models running at clock speeds from 1.0 GHz to 2.26 GHz . The models with lower frequencies were either low voltage or ultra-low voltage CPUs designed for improved battery life and reduced heat output. The 718 (1.3 GHz), 738 (1.4 GHz), and 758 (1.5 GHz) models are low-voltage (1.116 V) with a TDP of 10 W, while the 723 (1.0 GHz), 733 (1.1 GHz), and 753 (1.2 GHz) models are ultra-low voltage (0.940 V) with a TDP of 5 W.\n",
"BULLET::::- The Intel Core i7-975 Extreme Edition was considered the world's fastest desktop processor (until the i7-980x) by a review from Hot Hardware. It runs at a clock rate of 3.33 GHz with Turbo Boost clock rates running the processor up 3.46 GHz with all four cores put at work and 3.6 GHz with a single core at work. The processor was overclocked to 4.1 GHz while keeping a 50 °C (122 °F) core temperature with the stock cooling unit.\n",
"The Celeron M 523 (933 MHz ULV), M 520 (1.6 GHz), M 530 (1.73 GHz), 530 (1.73 GHz), 540 (1.86 GHz), 550 (2.0 GHz), 560 (2.13 GHz), 570 (2.26 GHz) are single-core 65 nm CPUs based on the \"Merom\" Core 2 architecture. They feature a 533 MT/s FSB, 1 MB of L2 cache (half that of the low end Core 2 Duo's 2 MB cache), XD-bit support, and Intel 64 technology, but lack SpeedStep and Virtualization Technology. Two different processor models are used with identical part numbers with the same part numbers, single-core Merom-L with 1 MB cache and dual-core Merom with 4 MB L2 cache that have the extra cache and core disabled. Celeron M 523, M 520 and M 530 are Socket M based, while Celeron 530 through 570 (without M) are for Socket P. January 4, 2008 marked the discontinuation of Merom CPUs.\n",
"A second generation 65 nm CMOS design contains 167 processors with dedicated fast Fourier transform (FFT), Viterbi decoder, and video motion estimation processors; 16 KB shared memories; and long-distance inter-processor interconnect. The programmable processors can individually and dynamically change their supply voltage and clock frequency. The chip is fully functional. Processors operate up to 1.2 GHz at 1.3 V which is believed to be the highest clock rate fabricated processor designed in any university. At 1.2 V, they operate at 1.07 GHz and 47 mW when 100% active. At 0.675 V, they operate at 66 MHz and 608 μW when 100% active. This operating point enables 1 trillion MAC or arithmetic logic unit (ALU) ops/sec with a power dissipation of only 9.2 watts. Due to its MIMD architecture and fine-grain clock oscillator stalling, this energy efficiency per operation is almost perfectly constant across widely varying workloads, which is not the case for many architectures.\n",
"The processor has 10.4 million transistors, is manufactured by BAE Systems using either 250 or 150 nm process and has a die area of 130 mm². It operates at 110 to 200 MHz. The CPU itself can withstand 200,000 to 1,000,000 Rads and temperature ranges between −55 and 125 °C.\n",
"The family of microcontrollers are 16-bit, however they do have some 32-bit operations. The processors operate at 16, 20, 25, and 50 MHz, and is separated into 3 smaller families. The HSI (high speed input) / HSO (high speed output) family operates at 16 and 20 MHz, and the EPA (event processor array) family operates at all of the frequencies.\n"
] |
Do rockets use fossil fuels? Is there danger of running out of rocket fuel as we deplete oil reserves in the next 50-200 years? If so, are there alternative fuels that have the necessary power to take us into space?
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We are in no danger of running out of liquid oxygen or liquid hydrogen, as they can be extracted from water. You can make a workable rocket with just those fuels, although a big fat first stage full of low density hydrogen has penalties.
Realistically, if absolute supply of kerosene or methane is an issue, we'll be too far gone to have the technical infrastructure to support spaceflights.
Helium is the real supply danger. It's irreplaceable as a pressurant and coolant and it is a nonrenewable resource. It's plentiful in space, but in limited supply on earth.
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[
"energy). In chemical rockets, unburned fuel or oxidizer represents the loss of chemical potential energy, which reduces the specific energy. However, most rockets run fuel-rich mixtures, which result in lower theoretical exhaust velocities.\n",
"Since solid-fuel rockets can remain in storage for a long time without much propellant degradation, and the fact that they almost always launch reliably, they have been frequently used in military applications such as missiles. The lower performance of solid propellants (as compared to liquids) does not favor their use as primary propulsion in modern medium-to-large launch vehicles customarily used to orbit commercial satellites and launch major space probes. Solids are, however, frequently used as strap-on boosters to increase payload capacity or as spin-stabilized add-on upper stages when higher-than-normal velocities are required. Solid rockets are used as light launch vehicles for low Earth orbit (LEO) payloads under 2 tons or escape payloads up to .\n",
"The exhaust gases produced by rocket propulsion systems, both in Earth's atmosphere and in space, can adversely effect the Earth's environment. Some hypergolic rocket propellants, such as hydrazine, are highly toxic prior to combustion, but decompose into less toxic compounds after burning. Rockets using hydrocarbon fuels, such as kerosene, release carbon dioxide and soot in their exhaust. However, carbon dioxide emissions are insignificant compared to those from other sources; on average, the United States consumed gallons of liquid fuels per day in 2014, while a single Falcon 9 rocket first stage burns around of kerosene fuel per launch. Even if a Falcon 9 were launched every single day, it would only represent 0.006% of liquid fuel consumption (and carbon dioxide emissions) for that day. Additionally, the exhaust from LOx- and LH2- fueled engines, like the SSME, is almost entirely water vapor. NASA addressed environmental concerns with its canceled Constellation program in accordance with the National Environmental Policy Act in 2011. In contrast, ion engines use harmless noble gases like xenon for propulsion.\n",
"Rocket fuel consists of solid, liquid and gel state fuels for propulsion. In order to power rockets, a fuel and an oxidiser are mixed within the combustion chamber, producing a high energy propulsive exhaust as thrust. The main uses for rocket fuel are for space shuttle boosters in order to propel the craft out of the atmosphere, or for missiles. Solid rocket propellant does not degrade in long-term storage and remains reliable on combustion. This allows munitions to remain loaded and fired when needed, which is highly regarded for military use. Once ignited, solid rocket propellants cannot be shutdown. The fuel and the oxidiser are stored within a metal casing. Once ignited, the fuel burns from the centre of the solid compound towards the edges of the metal casing. Burn rates and intensity are manipulated by the changing of the shape of a channel between the fuel and the casing shell. Two varieties of solid rocket fuel propellants exist. These include homogeneous and composite solid rocket fuels. These fuels are characteristically dense, stable at ordinary temperatures and easily storable. Liquid fuels are more controllable than solid rocket fuels, and can be shutoff after ignition and restarted, as well as offering greater thrust control. Liquid propellants are stored in two parts in an engine, as the fuel in one tank and an oxidiser in another. These liquids are mixed in the combustion chamber and ignited. Hypergolic fuel is mixed and ignites spontaneously, requiring no separate ignition. Liquid fuel compounds include petroleum, hydrogen and oxygen.\n",
"Boeing has suggested a non-extractive propellant depot, or \"space gas station,\" which accumulates material launched from the planet at low cost, allowing future lunar missions without the need for large launch vehicles like the Saturn V. MIT has recently proposed a similar plan which would store emergency fuel reserves left over from lunar missions.\n",
"Because they can be more energetic than the potential energy that chemical fuel allows for, some laser or microwave powered rocket concepts have the potential to launch vehicles into orbit, single stage. In practice, this area is not possible with current technology.\n",
"Beginning April 2006 there were some criticisms on the feasibility of the original ESAS study. These mostly revolved around the use of methane-oxygen fuel. NASA originally sought this combination because it could be \"mined\" in situ from lunar or martian soil – something that could be potentially useful on missions to these celestial bodies. However, the technology is relatively new and untested. It would add significant time to the project and significant weight to the system. In July, 2006, NASA responded to these criticisms by changing the plan to traditional rocket fuels (liquid hydrogen and oxygen for the LSAM and hypergolics for the CEV). This has reduced the weight and shortened the project's timeframe.\n"
] |
when a hard drive sets aside space for a download, what is it filled with before it actually receives the data that takes up the space?
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Logically, the filesystem is told to reserve the physical space for the new file.
Physically, the space of a hard drive that are reserved still contain whatever data was last in that space.
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[
"When data is deleted from storage devices, the references to the data are removed from the directory structure. The space can then be used, or overwritten, with data from other files or computer functions. The deleted data itself is not immediately removed from the physical drive and often exists as a number of disconnected fragments. This data, so long as it is not overwritten, can be recovered.\n",
"The hardware on the drive tells the actuator arm where it is to go for the relevant track and the compressed information is then sent down to the head which changes the physical properties, optically or magnetically for example, of each byte on the drive, thus storing the information. A file is not stored in a linear manner, rather, it is held in the best way for quickest retrieval.\n",
"If the data of a file fits in the space allocated for pointers to the data, this space can conveniently be used. For example, ext2 and its successors stores the data of symlinks (typically file names) in this way, if the data is no more than 60 bytes (\"fast symbolic links\").\n",
"The nearline storage system knows on which volume (cartridge) the data resides, and usually asks a robot to retrieve it from this physical location (usually: a tape library or optical jukebox) and put it into a tape drive or optical disc drive to enable access by bringing the data it contains online. This process is not instant, but it only requires a few seconds.\n",
"When a new file or directory is created, ext2 must decide where to store the data. If the disk is mostly empty, then data can be stored almost anywhere. However, clustering the data with related data will minimize seek times and maximize performance.\n",
"As a general rule, formatting a disk leaves most if not all existing data on the disk medium; some or most of which might be recoverable with special tools. Special tools can remove user data by a single overwrite of all files and free space.\n",
"File data storage was two-level: files could be either currently on disk, or, if the system was low on disk space they could be automatically relegated to magnetic tape. If an attempt was made to access a currently off line file the job would be suspended and the operators requested to load the appropriate tape. When the tape was made available the file would be brought back to disk and the job resumed.\n"
] |
subjective vs. objective
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Subjective is a judgement or experience. Objective is a reliably reproducible measurement. Both can be scientific. A good example is flavor versus chemistry.
A cherry is tangy, sweet. That's a subjective statement because everyone experiences flavor in a different way, but it's still important to science to characterize the properties of a cherry.
A cherry contains an average of 0.4 grams of fructose. That's an objective statement because we've distilled some measurement from an analysis.
|
[
"Some have argued that the distinction between objective and subjective assessments is neither useful nor accurate because, in reality, there is no such thing as \"objective\" assessment. In fact, all assessments are created with inherent biases built into decisions about relevant subject matter and content, as well as cultural (class, ethnic, and gender) biases.\n",
"The subjective theory of value is a theory of value that believes that an item’s value depends on the consumer. This theory states that an item’s value is not dependent on the labor that goes into a good, or any inherent property of the good. Instead, the subjective theory of value believes that a good’s value depends on the consumers wants and needs. The consumer places a value on an item by determining the marginal utility, or additional satisfaction of one additional good, of that item and deciding what that means to them.\n",
"The subjective standard and objective standard are legal standards for knowledge or beliefs of a defendant in a criminal law case. An objective standard of reasonableness requires the finder of fact to view the circumstances from the standpoint of a hypothetical reasonable person, absent the unique particular physical and psychological characteristics of the defendant. A subjective standard of reasonableness asks whether the circumstances would produce an honest and reasonable belief in a person having the particular mental and physical characteristics of the defendant, such as their personal knowledge and personal history, when the same circumstances might not produce the same in a general reasonable person.\n",
"The subjective theory of value presents what it sees as a solution to this paradox by arguing that value is not determined by individuals choosing between entire abstract classes of goods, such as all the water in the world versus all the diamonds in the world; rather an acting individual is faced with the choice between definite quantities of goods, and the choice made by such an actor is determined by which good of a specified quantity will satisfy the individual's highest subjectively ranked preference, or most desired end.\n",
"Assessment (either summative or formative) is often categorized as either objective or subjective. Objective assessment is a form of questioning which has a single correct answer. Subjective assessment is a form of questioning which may have more than one correct answer (or more than one way of expressing the correct answer). There are various types of objective and subjective questions. Objective question types include true/false answers, multiple choice, multiple-response and matching questions. Subjective questions include extended-response questions and essays. Objective assessment is well suited to the increasingly popular computerized or online assessment format.\n",
"The subjective theory of value is a theory of value which advances the idea that the value of a good is not determined by any inherent property of the good, nor by the amount of labor necessary to produce the good, but instead value is determined by the importance an acting individual places on a good for the achievement of his desired ends. The modern version of this theory was created independently and nearly simultaneously by William Stanley Jevons, Léon Walras, and Carl Menger in the late 19th century.\n",
"Moral realism is the view that there are mind-independent, and therefore objective, moral facts that moral judgments are in the business of describing. This combines a cognitivist view about moral judgments (that they are belief-like mental states in the business of describing the way the world is), a view about the \"existence\" of moral facts (that they do in fact exist), and a view about the \"nature\" of moral facts (that they are objective: independent of our cognizing them or our stance towards them). This contrasts with expressivist theories of moral judgment (\"e.g.\", Stevenson, Hare, Blackburn, Gibbard), error-theoretic/fictionalist denials of the existence of moral facts (\"e.g.\", Mackie, Richard Joyce, and Kalderon), and constructivist or relativist theories of the nature of moral facts (\"e.g.\", Firth, Rawls, Korsgaard, Harman).\n"
] |
Do we have any concept of "infinite" I terms of time and space?
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_URL_0_
> We now know (as of 2013) that the universe is flat with only a 0.4% margin of error. This suggests that the Universe is infinite in extent; [...] All we can truly conclude is that the Universe is much larger than the volume we can directly observe.
_URL_1_
> The size of the Universe is unknown; it may be infinite.
But
> how can it truly be without an end?
To imagine *that* it might be so is easy: Just look at e.g. Natural Numbers ([0,] 1, 2, 3, ...) - they go on without end, so why shouldn't something physical (like the size of space) be infinite (= go on forever)?
To imagine this infinity itself is probably forever impossible, but whenever I try to create a mental image of "Goes on forever. No, no just until that point - even further. And further.", I seem to find a new, more "correct" image of infinite space. Maybe I am re-using previous such mental images in the new one, like subroutines in a computer program. This can maybe never lead to an actual imagination of an infinite spatial stretch, but it feels like something new and awesome whenever I find a bigger mental image of this.
The actual question might be: Why should we be able to create mental images for everything that exists in reality? Maybe it just has to be accepted that reality is beyond our ability to mentally describe it (except by symbols and concepts). But don't let that discourage you from trying.
> When it comes to time, I know that we estimate the universe to be about 13.7 billion years old. I know we don't have a understanding of what was before that,
Well, that's an interesting problem, and I must admit that my musings in this regard might be unfit for /r/AskScience, but I dare write them anyway:
We (Mankind.) have found principles that reality follows, e.g. Quantum Mechanics, General Relativity etc. - and before we had found those, we had simpler, less accurate concepts of the principles that reality follows, and we had *more* of those because we didn't know yet what their underlying principle was. I'm saying that we had found a lot of small boxes, but nowadays we have a few larger boxes that each holds a lot of those earlier boxes. We keep searching for TheOneBoxToRuleThemAll™, the principle that all of reality follows.
But in the same way, when we look back further in time, we see a conceptually simpler and simpler universe. Our search for "the all-concept" and our search for what was at the beginning of the universe is a very similar one, it's ultimately looking for the same answer: What is reality ultimately really?
My take regarding the beginning of time is that the closer we'd get with our understanding to that point, the more we'd look at the all-unification of all things, the all-principle, and this would - my opinion - ultimately describe even what time is. Even what logic / cause & effect is. If that were so, then the beginning of time would be a singularity not just of space/matter/energy but also of all meanings. The question "what was before" would in this way not even have a meaning.
Just think of it this way: At some point in our mental journey to get closer to the root of the universe, we might find the explanation of what time is and how it works. And then? Well, and then there logically is no "before" any more.
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[
"Aristotle also distinguished \"things infinite in respect of divisibility\" (such as a unit of space that can be mentally divided into ever smaller units while remaining spatially the same) from things (or distances) that are infinite in extension (\"with respect to their extremities\").\n",
"The basic premise proceeds from the assumption that the probability of a world coming into existence exactly like our own is nonzero. If space and time are infinite, then it follows logically that our existence must recur an infinite number of times.\n",
"One such argument was based upon Aristotle's own theorem that there were not multiple infinities, and ran as follows: If time were infinite, then as the universe continued in existence for another hour, the infinity of its age since creation at the end of that hour must be one hour greater than the infinity of its age since creation at the start of that hour. But since Aristotle holds that such treatments of infinity are impossible and ridiculous, the world cannot have existed for infinite time.\n",
"Kraft made a distinction between time and eternity writing that \"the finite can never obtain eternity, but it can obtain an infinite time, (Aevum) or a time with beginning but without end.\" The infinite by contrast has permanence (\"sempiternité\")\".\n",
"The term is named after the German mathematician Richard Dedekind, who first explicitly introduced the definition. It is notable that this definition was the first definition of \"infinite\" that did not rely on the definition of the natural numbers (unless one follows Poincaré and regards the notion of number as prior to even the notion of set). Although such a definition was known to Bernard Bolzano, he was prevented from publishing his work in any but the most obscure journals by the terms of his political exile from the University of Prague in 1819. Moreover, Bolzano's definition was more accurately a relation that held between two infinite sets, rather than a definition of an infinite set \"per se\".\n",
"\"Only the Pythagoreans place the infinite among the objects of sense (they do not regard number as separable from these), and assert that what is outside the heaven is infinite. Plato, on the other hand, holds that there is no body outside (the Forms are not outside because they are nowhere), yet that the infinite is present not only in the objects of sense but in the Forms also. (Aristotle)\"\n",
"A full exposition of Philoponus' several arguments, as reported by Simplicius, can be found in Sorabji. One such argument was based upon Aristotle's own theorem that there were not multiple infinities, and ran as follows: If time were infinite, then as the universe continued in existence for another hour, the infinity of its age since creation at the end of that hour must be one hour greater than the infinity of its age since creation at the start of that hour. But since Aristotle holds that such treatments of infinity are impossible and ridiculous, the world cannot have existed for infinite time.\n"
] |
how does trade between countries work in terms of currency? if country a buys millions of dollars worth of commodities from country b, how do they pay? do they give them cash? gold? bank transfer?
|
Think of countries as regular companies for this case.
Countries don't really buy things - it's state companies that are run (more or less) like private companies, think of train networks requiring trains, power grids require generators, water networks needing pumps, etc. - when they buy something - and it doesn't matter if its domestic or foreign - they'll agree on a price (and a currency - especially in countries with weak local currencies, a strong foreign currency is actually agreed upon even on domestic deals) with the seller.
On longer running deals, most companies (state or private owned doesn't matter) then pay some insurance to have their exchange rate fixed (especially if the exchange rate between the local and foreign currency is more volatile) so they'll pay the same amount in their local currency for the foreign product over a longer amount of time.
|
[
"By an accounting identity, Country A's NCO is always equal to A's Net Exports, because the value of net exports is equal to the amount of capital spent abroad (i.e. outflow) for goods that are imported in A. It is also equal to the net amount of A's currency traded in the foreign exchange market over that time period. The value of exports (bananas, ice cream, clothing) produced in country A is always matched by the value of reciprocal payments of some asset (cash, stocks, real estate) made by buyers in other countries to the producers in country A. This value is also equal to the total amount of A's currency traded in the foreign exchange market over that year, because essentially the buyers in other countries trade in their assets (e.g. foreign currency) to convert to equivalent amount in A's currency, and use this amount to pay for A's export products.\n",
"In a fixed exchange-rate system, a country’s central bank typically uses an open market mechanism and is committed at all times to buy and/or sell its currency at a fixed price in order to maintain its pegged ratio and, hence, the stable value of its currency in relation to the reference to which it is pegged. To maintain a desired exchange rate, the central bank during a time of private sector net demand for the foreign currency, sells foreign currency from its reserves and buys back the domestic money. This creates an artificial demand for the domestic money, which increases its exchange rate value. Conversely, in the case of an insipient appreciation of the domestic money, the central bank buys back the foreign money and thus adds domestic money into the market, thereby maintaining market equilibrium at the intended fixed value of the exchange rate.\n",
"A commodity currency is a name given to some currencies that co-move with the world prices of primary commodity products, due to these countries' heavy dependency on the export of certain raw materials for income.\n",
"In the simplified case of two countries and two commodities, terms of trade is defined as the ratio of the total export revenue a country receives for its export commodity to the total import revenue it pays for its import commodity. In this case the imports of one country are the exports of the other country. For example, if a country exports 50 dollars' worth of product in exchange for 100 dollars' worth of imported product, that country's terms of trade are 50/100 = 0.5. The terms of trade for the other country must be the reciprocal (100/50 = 2). When this number is falling, the country is said to have \"deteriorating terms of trade\". If multiplied by 100, these calculations can be expressed as a percentage (50% and 200% respectively). If a country's terms of trade fall from say 100% to 70% (from 1.0 to 0.7), it has experienced a 30% deterioration in its terms of trade. When doing longitudinal (time series) calculations, it is common to set a value for the base year to make interpretation of the results easier.\n",
"Currency for international travel and cross-border payments is predominantly purchased from banks, foreign exchange brokerages and various forms of bureaux de change. These retail outlets source currency from the inter-bank markets, which are valued by the Bank for International Settlements at 5.3 trillion US dollars per day. The purchase is made at the spot contract rate. Retail customers will be charged, in the form of commission or otherwise, to cover the provider's costs and generate a profit. One form of charge is the use of an exchange rate that is less favourable than the wholesale spot rate. The difference between retail buying and selling prices is referred to as the bid–ask spread.\n",
"The main participants in this market are the larger international banks. Financial centers around the world function as anchors of trading between a wide range of multiple types of buyers and sellers around the clock, with the exception of weekends. Since currencies are always traded in pairs, the foreign exchange market does not set a currency's absolute value but rather determines its relative value by setting the market price of one currency if paid for with another. Ex: US$1 is worth X CAD, or CHF, or JPY, etc.\n",
"Under the gold standard, a country’s government declares that it will exchange its currency for a certain weight in gold. In a pure gold standard, a country’s government declares that it will freely exchange currency for actual gold at the designated exchange rate. This \"rule of exchange” allows anyone to enter the central bank and exchange coins or currency for pure gold or vice versa. The gold standard works on the assumption that there are no restrictions on capital movements or export of gold by private citizens across countries.\n"
] |
counterfeit vs fake vs forgery for items
|
A forgery usually refers to a *specific* item, like a signature or an original painting. If you were two see two identical copies of the same original painting, you could conclude that forgery has occurred merely from the fact that there are two of them. You still might need an expert to tell which one is the forgery, though.
Counterfeit is for *categories* of goods, and usually means that the thing being faked is the *origin*, not the good itself. Counterfeit is often, but not always, related to IP infringement.
If you make a purse, that's fine. If you make a purse and call it a Louis Vuitton, then it's a counterfeit because Louis Vuitton didn't make it (regardless if it's good quality or otherwise identical!). If Louis Vuitton licenses you to make LV-brand apparel, then that same purse is now not counterfeit anymore. In contrast to forgery, there's nothing inherently suspicious about seeing a dozen identical Louis Vuitton purses.
Bank notes are also counterfeit, because the thing being faked is who made them. The country issuing them is what gives them the legal weight to be considered money. So what you're faking is the issuing authority, and the good itself only incidentally.
Counterfeiting banknotes may also require forgery because there's signatures and art. Also, *financial instruments* can be forged: things like checks and deposit slips and authorizations.
"Fake" is a pretty loose term. I'm not sure it's well-defined.
|
[
"Sometimes, forgery is the method of choice in defrauding a bank. There are three main types of cheque forgery: (a) Counterfeit. This is a cheque that has been created on non-bank paper to look genuine. It relates to a genuine account. (b) Forged signature. The cheque is genuine, but the signature is not that of the account holder. (c) Fraudulently altered. In this case a genuine cheque has been made out by the genuine customer but it has been altered by a fraudster, typically by altering the recipient’s name or by adding words and/or digits in order to inflate the amount. In England and Wales, section 64 of the Bills of Exchange Act of 1882 provides that where a bill or an acceptance is materially altered without the assent of all parties liable on the bill, the bill is made void except when used against a party who has himself made, authorised or assented to the alteration, and subseqeunt endorsers.\n",
"Forgery is a white-collar crime that generally refers to the false making or material alteration of a legal instrument with the specific intent to defraud anyone (other than himself or herself). Tampering with a certain legal instrument may be forbidden by law in some jurisdictions but such an offense is not related to forgery unless the tampered legal instrument was actually used in the course of the crime to defraud another person or entity. Copies, studio replicas, and reproductions are not considered forgeries, though they may later become forgeries through knowing and willful misrepresentations. \n",
"There are essentially three varieties of art forger. The person who actually creates the fraudulent piece, the person who discovers a piece and attempts to pass it off as something it is not, in order to increase the piece's value, and the third who discovers that a work is a fake, but sells it as an original anyway.\n",
"Art forgery is the creating and selling of works of art which are falsely credited to other, usually more famous artists. Art forgery can be extremely lucrative, but modern dating and analysis techniques have made the identification of forged artwork much simpler.\n",
"The Forgery and Counterfeiting Act 1981 (c 45) is an Act of the Parliament of the United Kingdom which makes it illegal to make fake versions of many things, including legal documents, contracts, audio and visual recordings, and money of the United Kingdom and certain \"protected coins\". It replaces the Forgery Act 1913, the Coinage Offences Act 1936 and parts of the Forgery Act 1861. It implements recommendations made by the Law Commission in their report on forgery and counterfeit currency.\n",
"A forgery is essentially concerned with a produced or altered object. Where the prime concern of a forgery is less focused on the object itself – what it is worth or what it \"proves\" – than on a tacit statement of criticism that is revealed by the reactions the object provokes in others, then the larger process is a hoax. In a hoax, a rumor or a genuine object planted in a concocted situation, may substitute for a forged physical object.\n",
"To counterfeit means to imitate something authentic, with the intent to steal, destroy, or replace the original, for use in illegal transactions, or otherwise to deceive individuals into believing that the fake is of equal or greater value than the real thing. Counterfeit products are fakes or unauthorized replicas of the real product. Counterfeit products are often produced with the intent to take advantage of the superior value of the imitated product. The word \"counterfeit\" frequently describes both the forgeries of currency and documents, as well as the imitations of items such as clothing, handbags, shoes, pharmaceuticals, aviation and automobile parts, watches, electronics (both parts and finished products), software, works of art, toys, and movies.\n"
] |
How do you defend the purpose of Medieval History?
|
I don't actually feel as if I need to defend medieval history for its social relevance - the fact that I enjoy studying it is really enough for me. It should be obvious that medieval history presents special problems of understanding, in particular in relation to the number of sources, and I have always liked grappling with these.
I also don't buy the distinction you seem to be making between history which "has direct implications... and directly affects what occurs today" and that which doesn't. This is partly because I believe that the medieval period genuinely does affect today - you could think about the roots of the British constitution and legal system in terms of Magna Carta (1215); or the development of the English language via Middle English including the cultural legacy of the medieval period via Chaucer; or the way in which we link modern events to [those from medieval society](_URL_0_); or the ways that [modern culture](_URL_1_) draws on medieval tropes. Drawing this sort of distinction reduces history to a monocausal discipline which just considers immediate context, and I don't think that actually captures the past very well.
I'm also not sure how compelling a justification the one you use is. For one thing, I really don't think that people reading history necessarily apply the lessons of the past to the present - this is a bit crudely determinist for me.
A good introduction to the value of medieval history is Marcus Bull's *Thinking Medieval*.
|
[
"Medieval period oriented living history groups and reenactors focus on recreating civilian or military life in period of the Middle Ages. It is very popular in Eastern Europe. The goal of the reenactor and their group is to portray an accurate interpretation of a person who credibly could exist at a specific place at a specific point in time while at the same time remaining approachable to the public. Examples of living history activities include authentic camping, cooking, practicing historical skills and trades, and playing historical musical instruments or board games.\n",
"The book begins with a lengthy history of war crimes beginning with the \"knightly chivalry\" of the medieval period. These rules were put into place in order to minimize unnecessary cruelties during the course of warfare. The rules protected civilian populations from massacre and the needless spread of disease. Thus, the blanket of immunity that protects soldiers from being held criminally responsible for murder committed during the course of warfare had to be carefully balanced so as to discourage wartime atrocities.\n",
"A typical military confrontation in medieval times was for one side to lay siege to an opponent's castle. When properly defended, they had the choice whether to assault the castle directly or to starve the people out by blocking food deliveries, or to employ war machines specifically designed to destroy or circumvent castle defenses.\n",
"The book's third group of essays analyzes the rationale of self-defence as a justification for targeted killing. Washburn University School of Law professor Craig Martin writes in \"Going Medieval: Targeted Killing, Self-Defense and the Jus ad Bellum Regime\" that self-defence is not an appropriate rationale for targeted killing because such a justification is restricted to conflicts between state actors. University of Tulsa School of Law professor Russell Christopher writes in \"Imminence in Justified Targeted Killing\" that self-defence should be ruled out as a suitable position in several examples of potential conflict. He critiques arguments by governments including the United Kingdom and the United States that self-defense can be used as a rationalization of action against imminent danger. Western Washington University emeritus philosophy professor Phillip Montague says in an essay titled \"Defending Defensive Targeted Killings\" that use of this tactic against combatants can be seen as defensible and justified acts against terrorism or those who assist terrorist organizations.\n",
"These fortifications evolved over the course of the Middle Ages, the most important form being the castle, a structure which has become almost synonymous with the Medieval era in the popular eye. The castle served as a protected place for the local elites. Inside a castle they were protected from bands of raiders and could send mounted warriors to drive the enemy from the area, or to disrupt the efforts of larger armies to supply themselves in the region by gaining local superiority over foraging parties that would be impossible against the whole enemy host.\n",
"The Medieval Siege Society frequently performs at heritage sites around the UK and beyond, The Medieval Siege Society was formed in 1993 by a group of re-enactors and archers with an interest in Medieval reenactment and living history.\n",
"Medieval Scenarios and Recreations, Inc., known simply as MSR, is an educational non-profit Living History organization dedicated to the education, understanding and appreciation of the Middle Ages. The structure for this activity revolves around the Kingdom of Acre (\"pronounced AC-R\").\n"
] |
why do we still need sunscreen? why haven't we as humans adapted to the heat of the sun after all this time?
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> Why haven't we as humans adapted to the heat of the sun after all this time?
It's not the heat that's the problem. It's ultraviolet light, which damages cells and can lead to skin cancer. And we *have* adapted. Tanning is our body's response to excess sunlight, and it helps reduce (but does *not* eliminate) sun-related damage.
But skin cancer from sun exposure generally happens late enough in life that it has no impact on someone's ability to reproduce, and if it doesn't affect our ability to reproduce, then there is no evolutionary pressure to change it (i.e. pretty much no one who is more prone to UV-influenced cancer is dying before they can have children).
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[
"Sunlight has been shown to be beneficial in some skin conditions and enables the body to make vitamin D, but with the increased awareness of skin cancer, wearing of sunscreen is now part of the culture. Sun exposure prompts the body to produce nitric oxide that helps support the cardiovascular system and the feelgood brain-chemical serotonin.\n",
"Medical organizations such as the American Cancer Society recommend the use of sunscreen because it aids in the prevention of squamous cell carcinomas. Many sunscreens do not block UVA radiation, which does not cause sunburn but can increase the rate of melanoma and photodermatitis, so people using sunscreens may be exposed to high UVA levels without realizing it. The use of broad-spectrum (UVA/UVB) sunscreens can address this concern. Diligent use of sunscreen can also slow or temporarily prevent the development of wrinkles and sagging skin.\n",
"Sunscreen—Sunscreen is more transparent once applied to the skin and also has the ability to protect against UVA/UVB rays, although the sunscreen's ingredients have the ability to break down at a faster rate once exposed to sunlight, and some of the radiation is able to penetrate to the skin. In order for sunscreen to be more effective it is necessary to consistently reapply and use one with a higher sun protection factor.\n",
"A 2013 study concluded that the diligent, everyday application of sunscreen can slow or temporarily prevent the development of wrinkles and sagging skin. The study involved 900 white people in Australia and required some of them to apply a broad-spectrum sunscreen every day for four and a half years. It found that people who did so had noticeably more resilient and smoother skin than those assigned to continue their usual practices.\n",
"Sunscreen is effective and thus recommended to prevent melanoma and squamous-cell carcinoma. There is little evidence that it is effective in preventing basal-cell carcinoma. Other advice to reduce rates of skin cancer includes avoiding sunburning, wearing protective clothing, sunglasses and hats, and attempting to avoid sun exposure or periods of peak exposure. The U.S. Preventive Services Task Force recommends that people between 9 and 25 years of age be advised to avoid ultraviolet light.\n",
"Sunscreens are products commonly known by their capacity of protecting skin against sunburns. The active components present in sunscreens can vary, thus affecting the mechanism of protection against UV light, which can be done through absorption or reflection of UV energy. As UV light can cause mutations by DNA damaging, sunscreen is considered an antimutagenic compound as it blocks the action of the UV light to induce mutagenesis in cells, basically the sunscreen inhibit the penetration of the mutagen.\n",
"Sunscreen appears to be effective in preventing melanoma. In the past, use of sunscreens with a sun protection factor (SPF) rating of 50 or higher on exposed areas were recommended; as older sunscreens more effectively blocked UVA with higher SPF. Currently, newer sunscreen ingredients (avobenzone, zinc oxide, and titanium dioxide) effectively block both UVA and UVB even at lower SPFs. Sunscreen also protects against squamous cell carcinoma, another skin cancer.\n"
] |
Why does water turn yellow when electric current passes through it for some time?
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It's a physical reaction, not chemical, the electricity is causing it not an interaction of chemicals. Ions (atoms missing bits) come off the anode (positive side). If you leave wires connected to a battery in water for long enough you'll see one of them will eventually disintegrate. That's why you see metal for out doors that is anodized or galvanized . They put a metal coating that will degrade by giving up ions preventing the underlying metal from degradation.
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[
"Water attenuates light due to absorption which varies as a function of frequency. In other words, as light passes through a greater distance of water color is selectively absorbed by the water. Color absorption is also affected by turbidity of the water and dissolved material.\n",
"BULLET::::- Pure water is nearly colorless. However, it does absorb slightly more red light than blue, giving large volumes of water a bluish tint; increased scattering of blue light due to fine particles in the water shifts the blue color toward green, for a typically cyan net color.\n",
"In 2012, Johan Pettersson earned the Ig Nobel Prize in Chemistry for discovering why residents of some new houses in Anderslöv saw their hair turn green. He found that hot water left in pipes overnight peeled copper from them, leading to very high copper levels in the water.\n",
"Some solutions, like copper(II)chloride in water, change visually at a certain concentration because of changed conditions around the coloured ion (the divalent copper ion). For copper(II)chloride it means a shift from blue to green, which would mean that monochromatic measurements would deviate from the Beer–Lambert law.\n",
"Whitewater is formed in a rapid, when a river's gradient increases enough to generate so much turbulence that air is entrained into the water body, that is, it forms a bubbly or aerated and unstable current; the frothy water appears white. The term is also loosely used to refer to less turbulent, but still agitated, flows.\n",
"BULLET::::- Particles in water can scatter light. The Colorado River is often muddy red because of suspended reddish silt in the water. Some mountain lakes and streams with finely ground rock, such as glacial flour, are turquoise. Light scattering by suspended matter is required in order that the blue light produced by water's absorption can return to the surface and be observed. Such scattering can also shift the spectrum of the emerging photons toward the green, a color often seen when water laden with suspended particles is observed.\n",
"The experiment observed the light produced by relativistic electrons in the water created by neutrino interactions. As relativistic electrons travel through a medium, they lose energy producing a cone of blue light through the Cherenkov effect, and it is this light that is directly detected.\n"
] |
if i keep the calories down but it's all mtn dew & chocolate & chips, will i lose weight or stay fat from all the sugar?
|
If you eat fewer calories than you use, you lose weight.
If all those calories come from soda, chocolate, and chips, you lose other things. Like muscle mass, hair, and vital signs.
|
[
"While you don't need to limit the sugars found naturally in whole, unprocessed foods like fresh fruit, eating too much added sugar found in many processed foods can increase your risk for heart disease, obesity, cavities and Type 2 diabetes. The American Heart Association recommends women limit added sugars to no more than 100 calories, or 25 grams, and men limit added sugars to no more than 155 calories, or about 38.75 grams, per day. Currently, Americans consume an average of 355 calories from added sugars each day.\n",
"The USDA's recommended daily intake (RDI) of added sugars is less than 10 teaspoons per day for a 2,000-calorie diet. High caloric intake contributes to obesity if not balanced with exercise, with a large amount of exercise being required to offset even small but calorie-rich food and drinks.\n",
"Excessive consumption of large quantities of any energy-rich food, such as chocolate, without a corresponding increase in activity to expend the associated calories, can cause weight gain and possibly lead to obesity. Raw chocolate is high in cocoa butter, a fat which is removed during chocolate refining and then added back in varying proportions during the manufacturing process. Manufacturers may add other fats, sugars, and milk, all of which increase the caloric content of chocolate.\n",
"The suggested link between obesity and excess fructose consumption, as opposed to the excess consumption of any high-calorie food, is controversial. In March 2015 the World Health Organization recommended that free sugars comprise no more than ten percent of daily intake, and preferably no more than five percent (around six teaspoons or 25 grams).\n",
"Numerous agencies in the United States recommend reducing the consumption of all sugars, including HFCS, without singling it out as presenting extra concerns. The Mayo Clinic cites the American Heart Association's recommendation that women limit the added sugar in their diet to 100 calories a day (~6 teaspoons) and that men limit it to 150 calories a day (~9 teaspoons), noting that there is not enough evidence to support HFCS having more adverse health effects than excess consumption of any other type of sugar. The United States departments of Agriculture and Health and Human Services recommendations for a healthy diet state that consumption of all types of added sugars be reduced.\n",
"One hundred grams of brown sugar contains 377 Calories (nutrition table), as opposed to 387 Calories in white sugar (link to nutrition table). However, brown sugar packs more densely than white sugar due to the smaller crystal size and may have more calories when measured by volume.\n",
"The World Health Organization has advised reducing intake of free sugars, such as monosaccharides and disaccharides that are added to beverages by manufacturers, cooks, or consumers. Studies have supported WHO's guidance as well. A 2006 clinical trial found that when over weight or obese adults replaced caloric beverages with water or noncaloric beverages for 6 months, they averaged weight losses of 2–2.5%. In addition, The Obesity Society recommends minimizing children's intake of sugar-sweetened beverages.\n"
] |
Let's be honest: Is interstellar/intergallactic space travel possible at all?
|
You are pretty much correct in your analysis.
Long-term generation ships using nuclear pulse propulsion (or similar) could perhaps reach another star, but that technology is too far away to even say how far away it is.
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[
"Intergalactic travel is hypothetical manned or unmanned travel between galaxies. Due to the enormous distances between our own galaxy the Milky Way and even its closest neighbors—hundreds of thousands to millions of light-years—any such venture would be far more technologically demanding than even interstellar travel. Intergalactic distances are roughly a hundred-thousandfold (five orders of magnitude) greater than their interstellar counterparts.\n",
"Intergalactic travel involves spaceflight between galaxies, and is considered much more technologically demanding than even interstellar travel and, by current engineering terms, is considered science fiction.\n",
"Interstellar travel is the term used for crewed or uncrewed travel between stars or planetary systems. Interstellar travel will be much more difficult than interplanetary spaceflight; the distances between the planets in the Solar System are less than 30 astronomical units (AU)—whereas the distances between stars are typically hundreds of thousands of AU, and usually expressed in light-years. Because of the vastness of those distances, interstellar travel would require a high percentage of the speed of light; huge travel time, lasting from decades to millennia or longer. \n",
"BULLET::::7. The distance between planets makes interstellar travel impractical, particularly because of the amount of energy that would be required for interstellar travel using conventional means, (According to a NASA estimate, it would take 7 joules of energy to send the current space shuttle on a one-way, 50 year, journey to the nearest star, an enormous amount of energy) and because of the level of technology that would be required to \"circumvent\" conventional energy/fuel/speed limitations using exotic means such as Einstein-Rosen Bridges as ways to shorten distances from point A to point B.(see Faster-than-light travel).\n",
"For both crewed and uncrewed interstellar travel, considerable technological and economic challenges need to be met. Even the most optimistic views about interstellar travel see it as only being feasible decades from now. However, in spite of the challenges, if or when interstellar travel is realised, a wide range of scientific benefits is expected.\n",
"Looking beyond the Milky Way, there are at least 2 trillion other galaxies in the observable universe. The distances between galaxies are on the order of a million times farther than those between the stars. Because of the speed of light limit on how fast any material objects can travel in space, intergalactic travel would either have to involve voyages lasting millions of years, or a possible faster than light propulsion method based on speculative physics, such as the Alcubierre drive. There are, however, no scientific reasons for stating that intergalactic travel is impossible in principle.\n",
"While it takes light approximately 2.54 million years to traverse the gulf of space between Earth and, for instance, the Andromeda Galaxy, it would take a much shorter amount of time from the point of view of a traveler at close to the speed of light due to the effects of time dilation; the time experienced by the traveler depending both on velocity (anything less than the speed of light) and distance traveled (length contraction). Intergalactic travel for humans is therefore possible, in theory, from the point of view of the traveller.\n"
] |
If we never see objects fall into black holes due to time dilation, how do black holes gain mass?
|
It's a somewhat tricky question, actually.
From the point of view of the infalling particle, time doesn't slow down at all as it approaches the horizon; in fact, it doesn't feel anything special at the horizon at all, and it continues to fall in as normal.
To the outside, however, it's true that infalling matter appears to accrue on the surface of the black hole, and this is fine: the exterior gravitational field of a black hole of mass M is the same as that of a black hole with mass m1 surrounded by a shell of mass M-m1 on the horizon. As far as we're concerned, it doesn't matter if the matter falls in through the horizon or asymptotically reaches it because you'll get the same gravitational field either way.
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[
"As predicted by general relativity, the presence of a mass deforms spacetime in such a way that the paths taken by particles bend towards the mass. At the event horizon of a black hole, this deformation becomes so strong that there are no paths that lead away from the black hole.\n",
"To a distant observer, clocks near a black hole would appear to tick more slowly than those further away from the black hole. Due to this effect, known as gravitational time dilation, an object falling into a black hole appears to slow as it approaches the event horizon, taking an infinite time to reach it. At the same time, all processes on this object slow down, from the view point of a fixed outside observer, causing any light emitted by the object to appear redder and dimmer, an effect known as gravitational redshift. Eventually, the falling object fades away until it can no longer be seen. Typically this process happens very rapidly with an object disappearing from view within less than a second.\n",
"As more mass is accumulated, equilibrium against gravitational collapse reaches its breaking point. The star's pressure is insufficient to counterbalance gravity and a catastrophic gravitational collapse occurs in milliseconds. The escape velocity at the surface, already at least 1/3 light speed, quickly reaches the velocity of light. No energy nor matter can escape: a black hole has formed. All light will be trapped within an event horizon, and so a black hole appears truly black, except for the possibility of Hawking radiation. It is presumed that the collapse will continue.\n",
"If a black hole is very small, the radiation effects are expected to become very strong. A black hole with the mass of a car would have a diameter of about 10 m and take a nanosecond to evaporate, during which time it would briefly have a luminosity of more than 200 times that of the Sun. Lower-mass black holes are expected to evaporate even faster; for example, a black hole of mass 1 TeV/\"c\" would take less than 10 seconds to evaporate completely. For such a small black hole, quantum gravitation effects are expected to play an important role and could hypothetically make such a small black hole stable, although current developments in quantum gravity do not indicate this is the case.\n",
"Claims of intermediate mass black holes have been met with some skepticism. The heaviest objects in globular clusters are expected to migrate to the cluster center due to mass segregation. As pointed out in two papers by Holger Baumgardt and collaborators, the mass-to-light ratio should rise sharply towards the center of the cluster, even without a black hole, in both M15 and Mayall II.\n",
"If the mass of the remnant exceeds about (the Tolman–Oppenheimer–Volkoff limit), either because the original star was very heavy or because the remnant collected additional mass through accretion of matter, even the degeneracy pressure of neutrons is insufficient to stop the collapse. No known mechanism (except possibly quark degeneracy pressure, see quark star) is powerful enough to stop the implosion and the object will inevitably collapse to form a black hole.\n",
"A lower limit to the mass of the central black hole can be calculated using the Eddington luminosity. This limit arises because light exhibits radiation pressure. Assume that a black hole is surrounded by a disc of luminous gas. Both the attractive gravitational force acting on electron-ion pairs in the disc and the repulsive force exerted by radiation pressure follow an inverse-square law. If the gravitational force exerted by the black hole is less than the repulsive force due to radiation pressure, the disc will be blown away by radiation pressure.\n"
] |
why does traveling to new places generally make people happy?
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1. Humans have an instinctive desire to explore. Following our instincts feels good.
2. It distracts us from our usual daily concerns, which aren't visible there.
3. We don't have so many chores or work to do when on vacation.
|
[
"The new travelers have traveled the world, they have seen the classic sites. Staying at a Western hotel is not attractive enough, and they are excited by the prospect of experiencing the authentic local way of life: to go fishing with a local fisherman, to eat the fish with his family, to sleep in a typical village house. These tourists or travelers, are happy to know that while doing so they promote the economic well-being of those same people they spend time with.\n",
"Because of the Return to Sail opportunities, the young people get the sense of being part of something special and they look forward to coming back and doing it all again every year. These ongoing relationships, both with the Trust and the friends they have made over many different trips, are crucial in a young person being able to picture a bright future and having the increasing confidence to pursue that future. 30% of young people have attended more than four trips.\n",
"They travel all over the world to meet local youngsters and study the things young people like about a location such as sex, drugs, fashions and nightlife. In an attempt to \"change the formula of \"The Travel Show\"\" they want to make it funny and show that they don't care about the usual things a tourist cares about like history and architecture.\n",
"A new life experience meeting new people in a new place, and exploring the cultural heritage and natural environment unseen elsewhere, the members search for real beauty and happiness on foreign soil. The members travel to foreign countries to experience \"real happiness\" with locals. Unlike typical vacations, they live like locals and experience what a day in their life is like. Members must provide for themselves as no support from staff is given. The members experience the essence of culture, food, music, nature, and lifestyle while surviving on their own in the foreign country. This program is a differentiated real variety program providing affection and enlightenment to viewers.\n",
"“Travel makes the world look new, and when the world looks new, our brains work harder,” Kleon explains. Constraints can also act favorably – bad winters or summers can force you to be indoors and work on your projects.\n",
"A new form of travel emerged—Romantic travel—which focused on developing \"taste\", rather than acquiring objects, and having \"enthusiastic experiences\". \"History of a Six Weeks' Tour\" embodies this new style of travel. It is a specifically Romantic travel narrative because of its enthusiasm and the writers' desire to develop a sense of \"taste\". The travellers are open to new experiences, changing their itinerary frequently and using whatever vehicles they can find. For example, at one point in the journal, Mary Shelley muses:\n",
"These travelers see the journey as more than just tourism and take the trips in order to heal themselves and the world. Part of this may involve rituals involving (supposedly) leaving their bodies, possession by spirits (channelling), and recovery of past life memories. The travel is considered by many scholars as transcendental, a life learning process or even a self-realization metaphor.\n"
] |
how the conversion rates between currencies are decided. who, or what, decides these?
|
It works kind of like the stock market. Look up forex trading for details.
But basically a bunch of people make and take offers to trade one currency for another, and the rates those people are willing to trade at determine the exchange rate.
|
[
"Convertibility of a currency determines the ability of an individual, corporation or government to convert its local currency to another currency or vice versa with or without central bank/government intervention. Based on the above restrictions or free and readily conversion features, currencies are classified as:\n",
"The currency conversion software calculates the rates as decimal point numbers with typically 4 decimals after the comma. Some may calculate the conversion rates with more decimals internally but only 4 are displayed. This is related to precision, software internalization (i18n) and how the Forex (foreign exchange) market works, where most conversions have 4 decimal places, although some currency pairs also have 5. Most currency converters use up to 4.\n",
"A conversion factor is used to change the units of a measured quantity without changing its value. The unity bracket method of unit conversion consists of a fraction in which the denominator is equal to the numerator, but they are in different units. Because of the identity property of multiplication, the value of a quantity will not change as long as it is multiplied by one. Also, if the numerator and denominator of a fraction are equal to each other, then the fraction is equal to one. So as long as the numerator and denominator of the fraction are equivalent, they will not affect the value of the measured quantity.\n",
"Currency converters aim to maintain real-time information on current market or bank exchange rates, so that the calculated result changes whenever the value of either of the component currencies does. They do so by connecting to a database of current currency exchange rates. The frequency at which currency converters update the exchange rates they use varies: Yahoo currency converter updates its rates every day, while Convert My Money every hour.\n",
"Each conversion factor is chosen based on the relationship between one of the original units and one of the desired units (or some intermediary unit), before being re-arranged to create a factor that cancels out the original unit. For example, as \"mile\" is the numerator in the original fraction and formula_3, \"mile\" will need to be the denominator in the conversion factor. Dividing both sides of the equation by 1 mile yields formula_4, which when simplified results in the dimensionless formula_5. Multiplying any quantity (physical quantity or not) by the dimensionless 1 does not change that quantity. Once this and the conversion factor for seconds per hour have been multiplied by the original fraction to cancel out the units \"mile\" and \"hour\", 10 miles per hour converts to 4.4704 meters per second.\n",
"In terms of percentage changes (to a close approximation, under low growth rates), the percentage change in a product, say XY, is equal to the sum of the percentage changes %ΔX + %ΔY). So, denoting all percentage changes as per unit of time, \n",
"While metrication describes the adoption by different countries of a common system of decimalised metric measurements, countries generally have their own currencies. The decimalisation of currencies is the process of converting each country's currency from its previous non-decimal denominations to a decimal system, with one basic unit of currency and one or more sub-units, such that the number of sub-units in one basic unit is a power of 10, most commonly 100). The decimalisation process for individual countries is described below.\n"
] |
how does alka-seltzer work?
|
Stomach acid isn't there to break down your food, its primary role is to destroy bacteria in anything you just ate. The enzymes in your small intestine are responsible for most of the digestion.
Heartburn is caused by stomach acid finding its way up, and out of your stomach where it attacks the lining of your esophagus. Alka seltzer relieves heartburn by neutralizing that acid.
|
[
"It was developed by head chemist Maurice Treneer. Alka-Seltzer is marketed for relief of minor aches, pains, inflammation, fever, headache, heartburn, stomachache, indigestion, acid reflux and hangovers, while neutralizing excess stomach acid. It was launched in 1931.\n",
"Alka-Seltzer is an effervescent antacid and pain reliever first marketed by the Dr. Miles Medicine Company of Elkhart, Indiana, United States. Alka-Seltzer contains three active ingredients: aspirin (acetylsalicylic acid) (ASA), sodium bicarbonate, and anhydrous\n",
"In organic chemistry, keto–enol tautomerism refers to a chemical equilibrium between a keto form (a ketone or an aldehyde) and an enol (an alcohol). The keto and enol forms are said to be tautomers of each other. The interconversion of the two forms involves the movement of an alpha hydrogen atom and the reorganisation of bonding electrons; hence, the isomerism qualifies as tautomerism.\n",
"Fehling's solution is a chemical reagent used to differentiate between water-soluble carbohydrate and ketone functional groups, and as a test for reducing sugars and non-reducing sugars, supplementary to the Tollens' reagent test. The test was developed by German chemist Hermann von Fehling in 1849. But the solution has a drawback as it cannot differentiate between benzaldehyde and acetone. \n",
"An alkylation unit is one of the conversion processes used in petroleum refineries. It is used to convert isobutane and low-molecular-weight alkenes (primarily a mixture of propene and butene) into alkylate, a high octane gasoline component. The process occurs in the presence of a strong acting acid such as sulfuric acid or hydrofluoric acid (HF) as catalyst. Depending on the acid used, the unit takes the name of SAAU (Sulphuric Acid Alkylation Unit) or HFAU (Hydrofluoric Acid Alkylation Unit).\n",
"Alkylation is the transfer of an alkyl group from one molecule to another. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion or a carbene (or their equivalents). An alkyl group is a piece of a molecule with the general formula CH, where \"n\" is the integer depicting the number of carbons linked together. For example, a methyl group (\"n\" = 1, CH) is a fragment of a methane molecule (CH). Alkylating agents use selective alkylation by adding the desired aliphatic carbon chain to the previously chosen starting molecule. This is one of many known chemical syntheses. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character.\n",
"Selexol is the trade name for an acid gas removal solvent that can separate acid gases such as hydrogen sulfide and carbon dioxide from feed gas streams such as synthesis gas produced by gasification of coal, coke, or heavy hydrocarbon oils. By doing so, the feed gas is made more suitable for combustion and/or further processing. It is made up of dimethyl ethers of polyethylene glycol.\n"
] |
how does the opening bottle of wine in a shoe work?
|
Liquids don't compress. Holding the bottle upside down and striking the heel sends shockwaves through the bottle, which terminate in the spongey cork, causing it to move. Since it can't move into the liquids, it moves out of the neck.
|
[
"Wine bottle openers are required to open wine bottles that are stoppered with a cork. They are slowly being supplanted by the screwcap closure. There are many different inceptions of the wine bottle opener ranging from the simple corkscrew, the screwpull lever, to complicated carbon dioxide driven openers. The most popular is the wine key, sommelier knife or \"waiter's friend\" which resembles a pocket knife and has a small blade for cutting foil and a screw with a bottle brace.\n",
"This tool is used by businesses that need to open a large volume of wine efficiently and without waste or breakage. It is a large brass tubular device, fixed at a 45° angle to the bar, with a lever pivoted halfway and extending towards the user. The bottle's neck is inserted firmly in the lower aperture of the tube and the lever pulled down firmly and steadily to the bottom. This drives a corkscrew into the cork at a regular depth each time. When the lever is returned to its original position it extracts the cork. When the bottle is removed pull the lever to expose the cork at the bottom, it loosens the cork and returns the lever firmly to its starting position, whereupon the cork will then fall out.\n",
"Research in the late 1990s suggested that the ideal orientation for wine bottles is at a slight angle, rather than completely horizontal. This allows the cork to maintain partial contact with the wine in order to stay damp but also keeps the air bubble formed by a wine's ullage at the top rather than in the middle of the bottle if the wine is lying on its side. Keeping the ullage near the top, it has been argued, allows for a slower and more gradual oxidation and maturation process. This is because the pressure of the air bubble that is the ullage space rises and falls depending on temperature fluctuation. When exposed to higher temperatures the bubble's pressure increases (becomes positive relative to the air outside of the bottle), and if the wine is tilted at an angle, this compressed gas will diffuse through the cork and not harm the wine. When the temperature falls the process reverses.\n",
"Under most use, a bottle opener functions as a second-class lever: the fulcrum is the far end of the bottle opener, placed on the top of the crown, with the output at the near end of the bottle opener, on the crown edge, \"between\" the fulcrum and the hand: in these cases, one pushes \"up\" on the lever.\n",
"Although cork was historically chosen to seal wine bottle for other reasons (including its inert nature, impermeability, flexibility, sealing ability, and resilience), cork's poisson's ratio of zero provides another advantage. As the cork is inserted into the bottle, the upper part which is not yet inserted does not expand in diameter as it is compressed axially. The force needed to insert a cork into a bottle arises only from the friction between the cork and the bottle due to the radial compression of the cork. If the stopper were made of rubber, for example, (with a Poisson ratio of about 1/2), there would be a relatively large additional force required to overcome the radial expansion of the upper part of the rubber stopper.\n",
"The ullage level of a wine bottle is sometimes described as the \"fill level\". This describes the space between the wine and the bottom of the cork. During the bottling process, most wineries strive to have an initial ullage level of between 0.2–0.4 inches (5–10mm). As a cork is not a completely airtight sealant, some wine is lost through the process of evaporation and diffusion. As a wine ages in the bottle, the amount of ullage will continue to increase unless a wine is opened, topped up and recorked. If the wine is stored on its side, in contact with the cork, some wine will also be lost by absorption into the cork with longer corks having the potential to absorb more wine (and thus create more ullage) than shorter corks.\n",
"BULLET::::- It makes the bottle easier to clean prior to filling with wine. When a stream of water is injected into the bottle and impacts the punt, it is distributed throughout the bottom of the bottle and removes residues.\n"
] |
Why are many diseases that are potentially lethal to animals harmless to humans (and vice versa)?
|
A couple points:
1) yes, the tree of life contains a wide spectrum of immune systems. The innate immune system (macrophages, granulocytes e.g. neutrophils, complement proteins, etc) varies across the animal clade. The adaptive immune system (T and B lymphocytes and the lymphoid organs) also become increasingly complex as you move from primitive to complex animals as well. Check out [this review](_URL_1_) ([pdf](_URL_5_)). Simple things like physical barriers also play a role. Our skin is tough plating of keratinized cells, exposed to the air and thus is quite dry. We are much less susceptible to fungal infections as a result (unless the skin is always kept moist, e.g. like in a shoe, allowing athlete's foot to take root). Amphibians, which are usually thin-skinned and wet, making some [fungal infections lethal to them](_URL_0_).
2) viruses, which rely on host cells to replicate and survive, are always specific for a surface receptor of some kind to invade a cell. If this receptor is absent, the virus cannot invade from outside. Viruses that can cross from one animal to another (influenza, which can infect all sorts of mammals and birds) can do so because the receptors it requires evolved back before our last common ancestor. Think about that for a second: if the flu can infect a bird and a human, it must be able to infect any other animal (that hasn't since lost these receptors) that also came from that last common ancestor. Snakes arose from that ancestor, too, so snakes should be able to get the flu, right? [Yep. They can.](_URL_2_)
3) bacteria aren't usually dependent on host cells so much as they need the right environment. Some hosts simply cannot provide the right environment for bacteria to live. Ectothermic animals like small reptiles don't keep their body temps where some bacteria grow best, but we do. Other bacteria don't grow well at high heat, so we're safer from them. In fact, this is why we have fevers when we get sick.
4) advanced parasites require very specific aspects of host biology to reproduce. [Malaria](_URL_3_) is a great example: it is adapted to live in the GI tract, then the salivary glands, of a biting mosquito. After injection into a host's blood stream, it requires erythrocytes to reproduce. Without complex interactions between the parasite and its host (which induce [complex changes in parasite biology](_URL_4_)), the parasite can't reproduce. The malaria parasite simply cannot interact with non-host physiology in a way that lets it reproduce. This is just one example of parasite/host specificity- the world of parasites is filled with far more complex examples.
Hope that answers your question!
|
[
"Susceptible animals include cattle, water buffalo, sheep, goats, pigs, antelope, deer, and bison. It has also been known to infect hedgehogs and elephants; llamas and alpacas may develop mild symptoms, but are resistant to the disease and do not pass it on to others of the same species. In laboratory experiments, mice, rats, and chickens have been artificially infected, but they are not believed to contract the disease under natural conditions. Humans are rarely infected.\n",
"While this species is most frequently found in water and plants and is also found on animal and human skin, it is not a frequent human pathogen. Cases of \"C. albidus\" infection have increased in humans during the past few years, and it has caused ocular and systemic disease in those with immunoincompetent systems, for example, patients with AIDS, leukemia, or lymphoma. While systemic infections have been found with increasing regularity in humans, it is still relatively rare in animals. The administration of amphotericin B in animals has been successful, but in humans, the treatment usually has poor results.\n",
"In the 21st century billions of animals have been exposed to cruelty, for human’s benefit, in the United States and dozens of other countries worldwide through animal testing of consumer products. Laboratories sticking painful eye irritants into restrained rabbit’s eyes to test an eye product and cats being forced to have brain electrocutions to test for neurological pharmaceutical drugs are just two of hundreds of products tested on animals according to PETA (peta.org). Animals don’t have to be used for human’s wants. Scientists Burch and Russell created the 3Rs: reduction, refinement and replacement to further anti-vivisection. In these 3 Rs alternative successful approaches to testing consumer products have been created. Alternatives like in vitro, computer simulations, cell and tissue samples, and mannequins are reducing the millions of sentient animals forced into cruel and painful experiments worldwide.\n",
"Moreover, human health is endangered by unregulated trade in wild animals that can spread and pass on viruses and zoonotic diseases. SARS and Avian Influenza, for example, were transferred by wild animals to human beings. The lack of health standards within the trade chains increase the transmission of diseases to people, who come into contact with trafficked live or deceased animals.\n",
"Third, successful animals must not pose an obvious significant risk to human health and safety. Animals perceived as grave threats will incur the extreme ire of humans and be under constant threat of humans seeking to eliminate them.\n",
"Mammals susceptible to secondary poisoning include humans, with infants and small children being the most susceptible. Pets such as cats and dogs, as well as wild birds, also face significant risk of secondary poisoning.\n",
"A disadvantage is that any contact with pathogens may be fatal. This is because the animals have no protective bacterial microbiota on the skin or in the intestine or respiratory tract, and because they have no natural immunity to common infections as they have never been exposed to them.\n"
] |
How can exoplanets in systems whose planes do not allow transits visible to earth be detected?
|
There's a lot more methods to detect exoplanets. I'll summarize them :
1. Transit Photometry as you said. This detects only a tiny fraction of the exoplanets since you need aligned systems there could be tens of thousands of planets not seen because of misalignment. However this is the most successful technique right now with over 3000 detection (next best being radial velocity at around 750 detections).
2. Radial Velocity : The radial velocity method, also known as Doppler spectroscopy, is the most effective method for locating extrasolar planets with existing technology. The radial velocity method relies on the fact that a star does not remain completely stationary when it is orbited by a planet. It moves, ever so slightly, in a small circle or ellipse, responding to the gravitational tug of its smaller companion. When viewed from a distance, these slight movements affect the star's normal light spectrum. If the star is moving towards the observer, then its spectrum would appear slightly shifted towards the blue; if it is moving away, it will be shifted towards the red. Using highly sensitive spectrographs, we can track a star's spectrum, searching for periodic shifts towards the red, blue, and back again. The spectrum appears first slightly blue-shifted, and then slightly red-shifted. If the shifts are regular, repeating themselves at fixed intervals of days, months, or even years, it means that the star is moving ever so slightly back and forth - towards the Earth and then away from it in a regular cycle. This, in turn, is almost certainly caused by a body orbiting the star, and if it is of a low enough mass its a planet.
3. Microlensing : Microlensing is the only known method capable of discovering planets at truly great distances from the Earth. Whereas radial velocity searches look for planets in our immediate galactic neighborhood, up to 100 light years from Earth, and transit photometry can potentially detect planets at a distance of hundreds of light-years, microlensing can find planets orbiting stars near the center of the galaxy, thousands of light-years away. when the light emanating from a star passes very close to another star on its way to an observer on Earth, the gravity of the intermediary star will slightly bend the light rays from the source star, causing the two stars to appear farther apart than they normally would. If the source star is positioned not just close to the intermediary star when seen from Earth, but precisely behind it, this effect is multiplied. Light rays from the source star pass on all sides of the intermediary, or "lensing" star, creating what is known as an "Einstein ring". Even the most powerful Earth-bound telescope cannot resolve the separate images of the source star and the lensing star between them, seeing instead a single giant disk of light, where a star had previously been. The resulting effect is a sudden dramatic increase in the brightness of the lensing star. If a planet is positioned close enough to the lensing star so that it crosses one of the two light streams emanating from the source star, the planet's own gravity bends the light stream and temporarily produces a third image of the source star. When measured from Earth, this effect appears as a temporary spike of brightness, lasting several hours to several days, superimposed upon the regular pattern of the microlensing event. Such spikes are the telltale signs of the presence of a planet.
4. Astrometry : *Astrometry* is the method that detects the motion of a star by making precise measurements of its position on the sky. This technique can also be used to identify planets around a star by measuring tiny changes in the star's position as it wobbles around the center of mass of the planetary system. However, the precision required to detect a planet orbiting a star using this technique is extremely difficult to achieve and for this reason only one planet has been discovered by this method, although astrometry has been used to make follow-up observations for planets detected via other methods.
5. Direct Imaging : Direct imaging of exoplanets is extremely difficult, and in most cases impossible. Being small and dim planets are easily lost in the brilliant glare of the giant stars they orbit. Nevertheless, even with existing telescope technology there are special circumstances in which a planet can be directly observed.
For further reading see : [_URL_1_](_URL_1_) (you can see exact detection statistics here) and [_URL_0_](_URL_0_)
|
[
"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 the mass of a planet, and rule out other phenomena that can mimic the presence of a planet transiting a star, candidate transiting planets are followed up with the radial velocity method of detecting extrasolar planets.\n",
"When an exoplanet passes in front of the host star, a small dip in the light received from the star may be observed. The transit method is currently the most successful and responsive method for detecting exoplanets. This effect, also known as occultation, is proportional to the square of the planet's radius. If a planet and a moon passed in front of a host star, both objects should produce a dip in the observed light. A planet–moon eclipse may also occur during the transit, but such events have an inherently low probability.\n",
"The transit method also makes it possible to study the atmosphere of the transiting planet. When the planet transits the star, light from the star passes through the upper atmosphere of the planet. By studying the high-resolution stellar spectrum carefully, one can detect elements present in the planet's atmosphere. A planetary atmosphere, and planet for that matter, could also be detected by measuring the polarization of the starlight as it passed through or is reflected off the planet's atmosphere.\n",
"Present day searches for exoplanets are insensitive to exoplanets located at the distances from their host star comparable to the semi-major axes of the gas giants in the Solar System, greater than about 5 AU. Surveys using the radial velocity method require observing a star over at least one period of revolution, which is roughly 30 years for a planet at the distance of Saturn. Existing adaptive optics instruments become ineffective at small angular separations, limiting them to semi-major axes larger than about 30 astronomical units. The high contrast of the Gemini Planet Imager at small angular separations will allow it to detect gas giants with semi-major axes of 5–30 astronomical units.\n",
"The transit method can be used to discover exoplanets. As a planet eclipses/transits its host star it will block a portion of the light from the star. If the planet transits in-between the star and the observer the change in light can be measured to construct a light curve. Light curves are measured with a charged-coupled device. The light curve of a star can disclose several physical characteristics of the planet and star, such as, density. Multiple transit events must be measure to determine the characteristics which tend to occur at regular intervals if the others only one planet. Multiple planets orbiting the same host star can cause Transit Time Variations(TTV). TTV is cause by the gravitational forces of all orbiting bodies acting upon each other. The probability of seeing a transit from Earth is low, however. The probability is given by the following equation.\n",
"The moderate number of exoplanets discovered by Corot (32 during the 6 years of operation), is explained by the fact that a confirmation should absolutely be provided by ground-based telescopes, before any announcement is made. Indeed, in the vast majority of cases, the detection of several transits does not mean the detection of a planet, but rather that of a binary star system, either one that corresponds to a grazing occultation of a star by the other, or that the system is close enough to a bright star (the CoRoT target) and the effect of transit is diluted by the light of this star; in both cases the decrease in brightness is low enough to be compatible with that of a planet passing in front of the stellar disk. To eliminate these cases, one performs observations from the ground using two methods: radial velocity spectroscopy and imaging photometry with a CCD camera. In the first case, the mass of the binary stars is immediately detected and in the second case one can expect to identify in the field the binary system near the target star responsible for the alert: the relative decline of brightness will be greater than the one seen by Corot which adds all the light in the mask defining the field of measurement. In consequence, the COROT exoplanet science team has decided to publish confirmed and fully characterized planets only and not simple candidate lists. This strategy, different from the one pursued by the Kepler mission, where the candidates are regularly updated and made available to the public, is quite lengthy. On the other hand, the approach also increases the scientific return of the mission, as the set of published COROT discoveries constitute some of the best exoplanetary studies carried out so far.\n",
"There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like stars have an \"Earth-sized\" planet in the habitable zone. Assuming there are 200 billion stars in the Milky Way, it can be hypothesized that there are 11 billion potentially habitable Earth-sized planets in the Milky Way, rising to 40 billion if planets orbiting the numerous red dwarfs are included.\n"
] |
Why do we as humans often times feel he need to feed wild animals such as birds and fish when we get nothing in return?
|
Bear with me on this:
When our ancestors moved down from the trees and started to live in social groups out in the open this put selective pressure towards developing altruistic behavior. Some evolutionary biologists such as Robert Trivers argue that in humans this altruistic system is regulated by emotional dispositions. Altruism as a strategy makes sense for human-human interactions, whether we're talking symmetry-based altruism, attitudinal altruism or any other reciprocity mechanism. In this case let's focus on symmetry-based altruism with no cost to the giver, for example sharing the leftovers of a kill after you and your family are full instead of letting the remainder of it rot. There is no cost to you in sharing but you might get something in return later if you're nice and give the leftovers away to someone else. Fine and dandy. But how would this make sense for human-animal interactions? First consider that in the case above there is no cost to this behavior. Secondly we must assume that the emotional dispositions triggering the behavior isn't reserved for human-human interactions but in fact also apply in human-animal interactions. Seeing as there are no cost to sharing your spoils with animals there is also no selective pressure against this behavior. Now you may object to the assumption above stating that the emotional dispositions triggering the behavior isn't reserved for human-human interactions, but consider this: We find baby animals cute because there have been and is strong selective pressure towards bonding with our infant offspring. Recognizing infantile features in our children triggers this bonding, but a "side effect" of this mechanism is that infantile traits in animals also triggers a part of this system. We can assume the same has happened with our empathy, it was developed because of human-human social dynamics so we feel empathy for each other, but a "side effect" is that we also feel empathy for animals.
So then it follows that we feed animals because we feel compassionate towards them, and we feel compassionate towards them because there is selective pressure towards maintaining compassion and empathy in human-human interactions and no selective pressure against it from feeding animals with our surplus. It is likely that Ogg wouldn't feed the animals if he him self or his family were hungry, and so the extent of our compassion towards animals follows the same pattern as for human-human interactions, which is strongly regulated.
TLDR: Simpler explanation: we feel sorry for the hungry animals so we feed them or we feel good when we help them so we feed them. We feel this way for animals because we feel this way for each other. Biological Market Theory offer an explanation for why we feel this way and how these strategies developed over time as a result of natural selection.
|
[
"It is common for animals (even those like hummingbirds that have high energy needs) to forage for food until satiated, and then spend most of their time doing nothing, or at least nothing in particular. They seek to \"satisfice\" their needs rather than obtaining an optimal diet or habitat. Even diurnal animals, which have a limited amount of daylight in which to accomplish their tasks, follow this pattern. Social activity comes in a distant third to eating and resting for foraging animals. When more time must be spent foraging, animals are more likely to sacrifice time spent on aggressive behavior than time spent resting. Extremely efficient predators have more free time and thus often appear more lazy than relatively inept predators that have little free time. Beetles likewise seem to forage lazily due to a lack of foraging competitors. On the other hand, some animals, such as pigeons and rats, seem to prefer to respond for food rather than eat equally available \"free food\" in some conditions.\n",
"\"It is the duty of man to accustom himself to show kindness, compassion, and consideration to his fellow creatures. When we therefore treat considerately even the animals given for our use, and withdraw not from them some of the fruits of what their labor obtains for us, we educate our soul thereby to be all the kinder to our fellow men, and accustom ourselves not to withhold from them what is their due, but to allow them to enjoy with us the result of that to which they have contributed\" (par. 601).\n",
"Food is sought mainly on the ground where a large range of items are taken, such as insects, mollusks and other invertebrates (even from shallow water), grains, especially rice and it also searches among refuse for suitable food items left by humans. It appears to take less carrion than other species but will if the opportunity arises, and will also take eggs and nestlings.\n",
"The pets left behind in homes are often left without food or water. Some do not survive because of the lack of resources and are found dead when realtors or banks enter the premises. The animals are put in harm's way, and it is often believed it is done as a way to retaliate against those who took the home away.\n",
"need, we can measure the importance of a resource as perceived by the animals. Animals will be most highly motivated to interact with resources they absolutely need, highly motivated for resources that they perceive as most improving their welfare, and less motivated for resources they perceive as less important. Furthermore, Argument by analogy indicates that as with humans, it is more likely that animals will experience negative affective states (e.g. frustration, anxiety) if they are not provided with the resources for which they show high motivation.\n",
"Second, these animals are not tied to eating a specific type of food. For example, lynx do not thrive in human impacted environments because they rely so heavily on snowshoe hares. In contrast, raccoons have been very successful in urban landscapes because they can live in attics, chimneys, and even sewers, and can sustain themselves with food gained from trashcans and discarded litter. \n",
"How birds are without worry is also an open question. Fowler argues that it is because they are creatures of instinct. They follow the natural laws laid out by God without choice or deviation. If humans were equally as focused upon following the commands of God without hesitation we too would be without worry and anxiety. Nolland notes that this reference to animals doesn't fully reflect biological reality. There are many creatures that store and save food, and there are also many animals that die from starvation.\n"
] |
Can animals really predict disaster ahead?
|
The seizure sniffing dogs are a legit thing. They're a form of service animal that are *very* highly trained. I saw one assisting his "owner" (for lack of a better word in this context). About a minute before the guy started to seize, the dog did something (I didn't notice the signal, but apparently the guy did) to indicate that the seizure was about to start, the guy let me know what was about to happen and took a moment to roll his wheelchair over to an area with low foot traffic. The dog then kept guard on him for about a minute and a half while the seizure was happening, picked up the guy's dropped water bottle and put it back in his lap and gently nuzzled his hand once the seizure was ending. So, yeah, anecdotal, but totally legit.
As for animals detecting earthquakes, there was a really interesting segment on River Monsters where a Japanese scientist was studying the Nomazu catfish for signs of responses preceding earthquakes. Apparently, they will swim away from the bottom of the lake preceding an earthquake. I'm not sure how scientifically accurate the study was, as the fish were in tanks, but the implication and (presented) evidence seemed pretty strong to me.
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[
"For centuries there have been anecdotal accounts of anomalous animal behavior preceding and associated with earthquakes. In cases where animals display unusual behavior some tens of seconds prior to a quake, it has been suggested they are responding to the P-wave. These travel through the ground about twice as fast as the S-waves that cause most severe shaking. They predict not the earthquake itself — that has already happened — but only the imminent arrival of the more destructive S-waves.\n",
"Animals are also affected by their physical death, changes in food supply and changes in the microenvironment, the degree of survival differing with each affected category. For example, the physical numbers of bird populations were largely reduced by Hurricane Gilbert, but recovered quickly, while the populations that lived in forests with foliage damage took longer to recover. The effects of hurricanes on animals and their environment is significant, but the extent is unknown because of the multiple plant species and soil quality that influence the research of the ecology after a Hurricane.\n",
"The questionnaire asked whether dogs or other animals behaved strangely prior to the earthquake, whether there was a noticeable difference in the rise or fall of the water level in wells, and how many buildings had been destroyed and what kind of destruction had occurred. The answers have allowed modern Portuguese scientists to reconstruct the event with precision.\n",
"For Rupert Sheldrake's book \"Dogs That Know When Their Owners Are Coming Home\", Brown researched reports of animals anticipating earthquakes. Summarizing this research, Brown wrote \"Etho-Geological Forecasting\", which was published by Oxford University. Brown subsequently appeared on television programs about unusual animals: \"Extraordinary Cats\" for PBS \"Nature\", and the \"Psychic Animals\" episode of \"Animal X\" for the BBC and the Discovery Channel.\n",
"BULLET::::- \"The world is stranger than we can imagine and surprises are inevitable in science. Thus we found, for example, that pesticides increase pests, antibiotics can create pathogens, agricultural development creates hunger, and flood control leads to flooding. But some of these surprises could have been avoided if the problems had been posed big enough to accommodate solutions in the context of the whole.\" - Dr. Richard Levins\n",
"Existential risks pose unique challenges to prediction, even more than other long-term events, because of observation selection effects. Unlike with most events, the failure of a complete extinction event to occur in the past is not evidence against their likelihood in the future, because every world that has experienced such an extinction event has no observers, so regardless of their frequency, no civilization observes existential risks in its history. These anthropic issues can be avoided by looking at evidence that does not have such selection effects, such as asteroid impact craters on the Moon, or directly evaluating the likely impact of new technology.\n",
"Animal sentinels must have measurable responses to the hazard in question, whether that is due to the animal's death, disappearance, or some other determinable aspect. Many of these species are ideally unendangered and easy to handle. It is important that the species' range overlap with the range being studied. Often the ideal species is determined by the characteristics of the hazard.\n"
] |
What is the correlation between decibels and sound waves?
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I believe your confusion comes from thinking of decibels as being units used to measure sound waves. They aren't. The units typically used to measure sound waves are either micropascals RMS (for amplitude/pressure) or watts/meter^2 (for intensity). Decibels are, in general, just a convenient way to represent *ratios* that can vary over many [orders of magnitude](_URL_0_). In the specific case of sound pressure levels in air the decibels represent the ratio of the RMS pressure of the sound wave in question to the "reference level" which is by convention 20 uPa RMS.
So for example when someone says a sound is 60 dB they typically mean 60 dB re 20 uPa RMS which means that the pressure is 1,000 times greater than the reference level, or 20 millipascals RMS. That means that if you had a tiny and very sensitive pressure gauge and you watched the variation in pressure as the sound wave passed the reading on the pressure gauge would average out to 20 millipascals RMS.
|
[
"Sound is measured based on the amplitude and frequency of a sound wave. Amplitude measures how forceful the wave is. The energy in a sound wave is measured in decibels (dB), the measure of loudness, or intensity of a sound; this measurement describes the amplitude of a sound wave. Decibels (dB) are expressed in a logarithmic scale. On the other hand, pitch describes the frequency of a sound and is measured in hertz (Hz). \n",
"Probably the most common usage of \"decibels\" in reference to sound level is dB SPL, sound pressure level referenced to the nominal threshold of human hearing: The measures of pressure (a field quantity) use the factor of 20, and the measures of power (e.g. dB SIL and dB SWL) use the factor of 10.\n",
"The fraction of sound absorbed is governed by the acoustic impedances of both media and is a function of frequency and the incident angle. Size and shape can influence the sound wave's behavior if they interact with its wavelength, giving rise to wave phenomena such as standing waves and diffraction.\n",
"Sound that is perceptible by humans has frequencies from about 20 Hz to 20,000 Hz. In air at standard temperature and pressure, the corresponding wavelengths of sound waves range from to . Sometimes speed and direction are combined as a velocity vector; wave number and direction are combined as a wave vector.\n",
"The oscillations of sound waves can often be characterized in terms of \"frequency\". \"Pitches\" are usually associated with, and thus quantified as, \"frequencies\" (in cycles per second, or hertz), by comparing the sounds being assessed against sounds with pure tones (ones with periodic, sinusoidal waveforms). Complex and aperiodic sound waves can often be assigned a \"pitch\" by this method.\n",
"The amplitude of sound waves and audio signals (which relates to the volume) conventionally refers to the amplitude of the air pressure in the wave, but sometimes the amplitude of the displacement (movements of the air or the diaphragm of a speaker) is described. The logarithm of the amplitude squared is usually quoted in dB, so a null amplitude corresponds to −∞ dB. Loudness is related to amplitude and intensity and is one of the most salient qualities of a sound, although in general sounds can be recognized independently of amplitude. The square of the amplitude is proportional to the intensity of the wave.\n",
"Because many signals have a very wide dynamic range, signals are often expressed using the logarithmic decibel scale. Based upon the definition of decibel, signal and noise may be expressed in decibels (dB) as\n"
] |
Why does a wood stove burn more vigorously when the door is slightly ajar than when fully open?
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It's air pressure. When the stove is completely open, air pressure is roughly equalized so oxygen being burned is immediately replenished. When the door is only slightly open, the fire is using up the oxygen in the oven causing an area of low pressure, so the atmosphere outside of the oven "rushes in" to attempt to equalize. So the fire is getting more oxygen dumped onto it, feeding it more oxygen to burn.
|
[
"The wood is very dense and produces a hot flame when burned, which functions as an excellent source of heat for barbecues and wood-burning stoves. However, the wood is not desirable for wood fireplaces because the heat causes popping, thereby increasing the risk of house fires.\n",
"The system is more efficient than a fireplace, because the rate of combustion (and therefore the heat output) can be regulated by restricting the airflow into the firebox. Moreover, the air required for combustion does not have to pass through the interior of the building, which reduces cold drafts. Finally, because the firebox is not open to the interior, there is no risk of filling the interior with smoke.\n",
"Fireplace inserts are invariably made from cast iron or steel and most have self-cleaning glass doors that allow the flames of the fire to be viewed while the insulated doors remain closed, making the fire more efficient. This makes use of an \"air wash\" system whereby clean air is directed across the interior surface of the glass and thus prevents the buildup of deposits.\n",
"Burning wood fuel in an open fire is both extremely inefficient (0-20%) and polluting due to low temperature partial combustion. In the same way that a drafty building loses heat through loss of warm air through poor sealing, an open fire is responsible for large heat losses by drawing very large volumes of warm air out of the building.\n",
"The primary advantage of hardwoods are that they tend to contain more potential energy than the same volume of a softwood, thus increasing the amount of potential heat that can be stacked into one stoveload. Hardwood tends to form and maintain a bed of hot coals, which release lower amounts of heat for a long time. Hardwoods are ideal for long, low burns, especially in stoves with a poor ability to sustain a low burn, or in mild weather when high heat output is not required.\n",
"In a conventional stove, when wood is added to a hot fire, a process of pyrolysis or destructive distillation begins. Gases (or volatiles) are evolved which are burned above the solid fuel. These are the two distinct processes going on in most solid fuel appliances. In obsolete stoves without secondary combustion, air had to be admitted both below and above the fuel to attempt to increase combustion and efficiency. The correct balance was difficult to achieve in practice, and many obsolete wood-burning stoves only admitted air above the fuel as a simplification. Often the volatiles were not completely burned, resulting in energy loss, chimney tarring, and atmospheric pollution.\n",
"Fireplace inserts are popular with people who have an existing open fireplace and chimney, since they significantly improve both fuel efficiency and heat output while also providing an attractive focal point to a room. The disadvantages when compared to a free standing wood burning stove are that they are more expensive to install and depend upon there being a usable fireplace and chimney in the first place.\n"
] |
Did any ancient civilisation ever actually build the kinds of complex mechanical puzzles you see in popular fiction like Indiana Jones, Tomb Raider, Uncharted, National Treasure etc?
|
Hi, you may be interested in a couple of posts from [the FAQ](_URL_2_):
* [Were the tombs of South American civilizations the booby-trapped nightmare we see in entertainment?](_URL_1_) - South & amp; Central America, Egypt
* [Many fantasy/historical computer games and RPGs feature "dungeons", ie a large labyrinthian set of tunnels, rooms, traps etc. Is there any historical basis for dungeons?](_URL_0_) - various labyrinths & amp; catacombs
If you have follow-up questions, since these posts are archived, just ask here & tag the user's username to notify them
|
[
"The oldest known mechanical puzzle also comes from Greece and appeared in the 3rd century BCE. The game consisted of a square divided into 14 parts, and the aim was to create different shapes from these pieces. In Iran \"puzzle-locks\" were made as early as the 17th century (AD).\n",
"Eblong likened the game's puzzle design to games such as \"Zork Grand Inquisitor\", \"Myst\", and \"Traitors Gate\" though noted that puzzles are completed by doing chemistry experiments rather than using spells, in-universe mythology or technological gizmos respectively. Metzomagic praised the game's graphics and musical score, and deemed it harder than its sister games Physicus and Bioscopia. Adventure Gamers thought the concept was admirable and was interesting in playing the sequel.\n",
"Complex mechanical devices are known to have existed in Hellenistic Greece, though the only surviving example is the Antikythera mechanism, the earliest known analog computer. It is thought to have come originally from Rhodes, where there was apparently a tradition of mechanical engineering; the island was renowned for its automata; to quote Pindar's seventh Olympic Ode:\n",
"BULLET::::1. All of the puzzles in the game reference real, albeit esoteric, references to various cultures and archeological history and studies. A common example would be the exploration of the pyramids in Egypt along with the mythology that surrounds them, but uncommonly known examples were chosen over better-known ones. Mark's overseas duties in the U.S. Army (retired Major) combined with a year of historical research enhanced the puzzles that must be solved to finish the game.\n",
"This genre is set in an alternate universe in which civilizations during the Ancient era have access to advanced fantastic Bronze-Age (bronzepunk) or Iron-Age (ironpunk) technology. This would potentially lead to a less-isolated retro-futurist Greece that was never conquered or a retro-futurist Roman Empire that never fell. Prime examples would be the mechanical wonders in films like \"Jason and the Argonauts\" (1963) and \"Clash of the Titans\" (1981) or the \"God of War\" video game series. High-technology in such works is rare (usually a \"one-off\" by a genius philosopher or a hand-crafted \"trade secret\" product made by workshops of artificiers) but potentially indistinguishable from miracles or magic. Another example is the retro-futuristic blend of Imperial Rome and 1930s Fascist Italy in Julie Taymor's \"Titus\" (1999). There are motor vehicles, radios, and simple firearms, but war is still waged by armor-clad troops with swords and spears. \n",
"The next known occurrence of puzzles is in Japan. In 1742 there is a mention of a game called \"Sei Shona-gon Chie No-Ita\" in a book. Around the year 1800 the Tangram puzzle from China became popular, and 20 years later it had spread through Europe and America.\n",
"Once Barwood and Falstein completed the rough outline of the story, Barwood wrote the actual script, and the team began to conceive the puzzles and to design the environments. The Atlantean artifacts and architecture devised by lead artist William Eaken were made to resemble those of the Minoan civilization, while the game in turn implies that the Minoans were inspired by Atlantis. Barwood intended for the Atlantean art to have an \"alien\" feel to it, with the machines seemingly operating on as yet unknown physics rather than on magic. The backgrounds were first pencil sketched, given a layer of basic color and then converted and touched up with 256-colors. Mostly they were mouse-drawn with Deluxe Paint, though roughly ten percent were paintings scanned at the end of the development cycle. As a consequence of regular design changes, the images often had to be revised by the artists. Character animations were fully rotoscoped with video footage of Steve Purcell for Indiana's and Collette Michaud for Sophia's motions. The main art team that consisted of Eaken, James Dollar and Avril Harrison was sometimes consulted by Barwood to help out with the more graphical puzzles in the game, such as a broken robot in Atlantis.\n"
] |
What can we make using the 6 elements in the /r/askscience logo?
|
Pretty much none. Neon is a noble gas which won't form compounds with much and definitely not with all of these at any reasonable energy. You might be able to squeeze everything but Ne onto some long molecule all as substituted atoms, but even that would be a stretch. The only compound that sticks out containing two of these is potassium iodide though I'm sure cerium/scandium iodide are kicking around and maybe a few arsenic compounds as well.
|
[
"The company takes its name from scandium, the 21st element of the periodic table, alloys of which are used to make golf clubs and fishing rods. Element 21 claims that their use of scandium improves performance compared with that of other commonly used metals.\n",
"The symbols of chemical elements are evenly spaced along the top edge of the facade in the side wings of the Chemistry Faculty building. The 24 characters - heavily stylized abbreviations of the symbols of chemical elements - have been divided into 4 groups of 6 symbols each. The non-metals were placed on the west wing, while metals on the east one.\n",
"Another common symbol of the five elements is the \"gorintō\", a stone tower of modest size used mainly in Buddhist temples and cemeteries. It is composed from bottom to top of a cube, a sphere, a triangle, a crescent and something resembling a lotus flower, shapes that also have the meaning described above.\n",
"The IUPAC's rules for naming organic and inorganic compounds are contained in two publications, known as the \"Blue Book\" and the \"Red Book\", respectively. A third publication, known as the \"Green Book\", describes the recommendations for the use of symbols for physical quantities (in association with the IUPAP), while a fourth, the \"Gold Book\", contains the definitions of a large number of technical terms used in chemistry. Similar compendia exist for biochemistry (the \"White Book\", in association with the IUBMB), analytical chemistry (the \"Orange Book\"), macromolecular chemistry (the \"Purple Book\") and clinical chemistry (the \"Silver Book\"). These \"color books\" are supplemented by shorter recommendations for specific circumstances that are published periodically in the journal \"Pure and Applied Chemistry\".\n",
"The article was based on an award-winning exhibit that was assembled by Jay and Marieli Roe (a.k.a. Dr. John Westel Rowe, an organic chemist in Wisconsin, and his wife Marieli Rowe), and shown during the 1987–1990 period. The 24 elements named are: Al, Sb, C, Co, Cu, Au, Hf, Fe, Pb, Mg, Mo, Ni, Nb, Pd, Pt, Re, Ag, Ta, Sn, Ti, W, V, Zn and Zr.\n",
"Asterisk is a core component in many commercial products and open-source projects. Some of the commercial products are hardware and software bundles, for which the manufacturer supports and releases the software with an open-source distribution model.\n",
"The current logo of eltrece originated in 1994, consisting of a 12-pointed sun that in turn consists of four colored elements - violet, red, orange and yellow - intertwined around an open center and arranged from right to left. The company responsible for the realization and aesthetic renovations of the current badge is the American company C & G Partners, under the coordination of Artear's communication and image area.\n"
] |
When 'unlikely' animals tolerate the company of each other, what is happening at a psychological level?
|
A polite reminder. This is AskScience. No layman speculation, no guessing, no anecdotes, no jokes. Please check the sidebar if you're unsure whether your answer should be here or not.
|
[
"In real life situations, animals (including humans) have to cope with stresses generated within their own species, during their interactions with conspecifics, especially due to recurrent struggles over the control of limited resources, mates and social positions (Bjorkqvist, 2001; Rohde, 2001; Allen & Badcock, 2003).\n",
"Cooperative behavior of many animals can be understood as an example of the prisoner's dilemma. Often animals engage in long term partnerships, which can be more specifically modeled as iterated prisoner's dilemma. For example, guppies inspect predators cooperatively in groups, and they are thought to punish non-cooperative inspectors.\n",
"Self-validating reduction applies beyond the human sphere as well. For example, wild animals who were not originally hostile or wary become that way upon being hunted. Scientific research on other animals that tends to avoid calling on their social instincts, in the name of objectivity, may in fact drive them away and actually induce an avoidance of humans that then is taken to be an objective and independent fact about them. Highly confined and managed animals under \"factory farming\" can be reduced to a state of social and physical dysfunction that seems to be their \"inherent character\", as Douglass puts it, thus making their treatment less morally troubling, and thereby making them more available for further reduction in turn.\n",
"An interesting area of research in this context concerns the similarities between our relationships and those of animals, whether animals in human society (pets, working animals, even animals grown for food) or in the wild. One idea is that as people or animals perceive a social relationship as important to preserve, their \"conscience\" begins to respect that former \"other\", and urge actions that protect it. Similarly, in complex territorial and cooperative breeding bird communities (such as the Australian magpie) that have a high degree of etiquettes, rules, hierarchies, play, songs and negotiations, rule-breaking seems tolerated on occasions not obviously related to survival of the individual or group; behaviour often appearing to exhibit a touching gentleness and tenderness.\n",
"Interspecific competition may occur when individuals of two separate species share a limiting resource in the same area. If the resource cannot support both populations, then lowered fecundity, growth, or survival may result in at least one species. Interspecific competition has the potential to alter populations, communities and the evolution of interacting species. An example among animals could be the case of cheetahs and lions; since both species feed on similar prey, they are negatively impacted by the presence of the other because they will have less food, however they still persist together, despite the prediction that under competition one will displace the other. In fact, lions sometimes steal prey items killed by cheetahs. Potential competitors can also kill each other, in so-called 'intraguild predation'. For example, in southern California coyotes often kill and eat gray foxes and bobcats, all three carnivores sharing the same stable prey (small mammals).\n",
"Animals have two types of effects, direct and indirect, on a mental health spectrum including biological, psychological, and social responses, further targeting marked symptoms of PTSD (i.e., re-experiencing, avoidance, changes in beliefs/feelings, and hyperarousal). Direct effects of animals include a decrease in anxiety and blood pressure while indirect effects result in increased social interactions and overall participation in everyday activities.\n",
"Other animal activities may be misinterpreted due to the frequency and context in which animals perform the behaviour. For example, domestic ruminants display behaviours such as mounting and head-butting. This often occurs when the animals are establishing dominance relationships and are not necessarily sexually motivated. Careful analysis must be made to interpret what animal motivations are being expressed by those behaviours.\n"
] |
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