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If your body produces antibodies after defeating a pathogen indefinitely, when an individual gets exposed to many pathogens throughout their life, will they have a larger antibody density in their blood? Is there a limit to this?
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Antibodies are made as you require them. They are made by lymphocytes, after an infection you havea low number lymphocytes called memory cells in your blood these can build the antibodies required if you are exposed to the pathogen again.
The original process of producing an antibody for an infection is a random process.
Immunity comes about because correct antibodies can be produced faster the second time you have an infection.
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[
"Even if the host does develop antibodies, protection might not be adequate; immunity might develop too slowly to be effective in time, the antibodies might not disable the pathogen completely, or there might be multiple strains of the pathogen, not all of which are equally susceptible to the immune reaction. However, even a partial, late, or weak immunity, such as a one resulting from cross-immunity to a strain other than the target strain, may mitigate an infection, resulting in a lower mortality rate, lower morbidity, and faster recovery.\n",
"Once a bacterium or virus overcomes the body's innate immune system, the host organism's acquired immune system will take over. This immune response is highly specific to pathogens and provides the host with long-lasting immunity against future infection by that specific pathogen. When lymphocytes recognize antigens presented on a pathogen's surface, they will secrete antibodies that bind to the pathogen and alert macrophages and natural killer cells. These cells target the pathogen itself, killing it or rendering it inactive. This process further produces memory B cell and memory T cells that allow long-lasting immunity to occur.\n",
"These antibodies will then act to destroy the parasites that circulate around the blood. However, from the several parasites present in the plasma, a small number of them will experience changes in their surface coats resulting in the formation of new VSGs. Thus, the antibodies produced by the immune system will no longer recognize the parasite leading to proliferation until new antibodies are created to combat the novel VSGs. Eventually the immune system will no longer be able to fight off the parasite due to the constant changes in VSGs and infection will arise.\n",
"The infectious dose of a pathogen is the number of cells required to infect the host. All pathogens have an infectious dose typically given in number of cells. The infectious dose varies by organism and can be dependent on the specific type of strain. Some pathogens can infect a host with only a few cells, while others require millions or billions.\n",
"Although there are many diverse pathogens, many of which are constantly mutating, it is a surprise that a majority of individuals remain free of infections. Thus, maintenance of health requires the body to recognize all pathogens (antigens they present or produce) likely to exist. This is achieved by maintaining a pool of immensely large (about 10) clones of B cells, each of which reacts against a specific epitope by recognizing and producing antibodies against it. However, at any given time very few clones actually remain receptive to their specific epitope. Thus, approximately 10 different epitopes can be recognized by all the B cell clones combined. Moreover, in a lifetime, an individual usually requires the generation of antibodies against very few antigens in comparison with the number that the body can recognize and respond against.\n",
"Infection with most pathogens does not result in death of the host and the offending organism is ultimately cleared after the symptoms of the disease have waned. This process requires immune mechanisms to kill or inactivate the inoculum of the pathogen. Specific acquired immunity against infectious diseases may be mediated by antibodies and/or T lymphocytes. Immunity mediated by these two factors may be manifested by:\n",
"In conclusion, if a pathogen is capable of overcoming various host defenses, recognizing a host cell for infection, and successfully replicating within a host tissue, then the pathogen is likely to possess tropism for that specific host.\n"
] |
why aren't there any laws limiting the use of plastic?
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Because people want plastic things, a lot. The innovation of plastic products completely changed the world. People in general don't want to stop using plastic.
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[
"Recycling, banning, and taxation fails to adequately reduce the pollution caused by plastic bags. An alternative to these policies would be to increase extended producer responsibility. In the US, under the Clinton presidency, the President's Council on Sustainable Development suggested EPR in order to target different participants in the cycle of a product's life. This can, however, make the product more expensive since the cost must be taken into consideration before being put on the market, which is why it is not widely used in the United States currently. Instead, there is banning or taxation of plastic bags, which puts the responsibility on the consumers. In the United States, EPR has not successfully been made mandatory, instead being voluntary. What has been recommended is a comprehensive program which combines taxation, producer responsibility, and recycling to combat pollution.\n",
"Due to their low cost, ease of manufacture, versatility, and imperviousness to water, plastics are used in a multitude of products of different scale, including paper clips and spacecraft. They have prevailed over traditional materials, such as wood, stone, horn and bone, leather, metal, glass, and ceramic, in some products previously left to natural materials.\n",
"The Canadian government has plans to ban single-use plastics as early as 2021, the list of items to be banned includes plastic straws, cotton swabs, stirrers, plates, cutlery as well as balloon sticks.\n",
"But subsequent ACC efforts to prevent adoption of municipal ordinances banning plastic bags have not been successful. Over ACC opposition, San Jose, California, in 2010 adopted California's strictest ban. The ordinance, in effect since 2012, prohibits supermarkets, pharmacies, corner shops and others from distributing single-use plastic bags, with fines for violations. Retailers can sell paper bags made of 40 percent recycled materials for 10 cents each, gradually increasing to 25 cents by 2014. In 2016, California voters approved a statewide ban on carry-out plastic bags.\n",
"It was reported that roughly 50% of plastics are being utilized in disposable manufacturing processes such as packaging, agricultural films, and disposables, while 20 to 25 % was used for long-term infrastructure like pipes, coating for cables and structured materials and the remainder is used for durable moderate life consumer goods such as electronics, furniture, and vehicles. In general, plastic is considered to be durable and non-biodegradable hence making them difficult to decompose for at least a few decades with some lasting over hundreds or thousands of years. Judging from the domestic environmental factors, even some degradable plastics may still exist for a considerable period of time due to their degradation rate which is also influenced by factors such as the exposure of UV, oxygen, and temperature, whereas biodegradable plastics require the need of adequate microorganisms. Therefore, the rate of degradation in landfills and terrestrial, marine environments would tend to vary. \n",
"The use of plastics continues to rise in our daily lives due to its convenience and cheap price. But the cost that is not obvious to many is the environmental and health impacts they are leaving behind.\n",
"On April 19, 2018, ahead of Earth Day, a proposal to phase out single-use plastics was announced during the meeting of the Commonwealth Heads of Government. This will include plastic drinking straws, which cannot be recycled and contribute to ocean deterioration, damaging ecosystems and wildlife. It is estimated that as of 2018, about 23 million straws are used and discarded daily in the UK. Plastic straws will be banned in England from April 2020. However, there will be exemptions for those who require plastic straws due to disability.\n"
] |
In "The Dialectic of Sex," Shulamith Firestone claims that childhood was essentially an invention of the 15th century, and that before that point male children were treated as adults and functioned perfectly well in adult society. Is this true?
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I'm not familiar with Firestone's book, but I've written a few times on childhood and adolescence in the premodern world here on AH.
* [Historiography of children and childhood](_URL_0_)
* [Is adolescence an invention of the 20th century?](_URL_1_) (This has more to do with teenage-hood as a distinct life stage)
Mentioned in the second post, Shahar and Hanawalt provide some of the clearest evidence that medieval boys, specifically, were not merely "little men." They show how boys (into teenagehood!) did spend some of their leisure time engaging in some activities practiced by men--but they were still excluded from some, and they still spent some of their time in children's/women's activities. Latin chroniclers also distinguish between youths and boys of "full maturity."
Parents writing letters to their sons at university (think ages 15-20) seem quite sure that those sons are not ready to be fully functioning adults, what with how they throw money away on frivolties and neglect their studies and brawl violently at bars.
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[
"Her book \"Meanings of Sex Difference in the Middle Age: Medicine, Science, and Culture\" (1993) was groundbreaking in its examination of sex and gender, and has deeply influenced subsequent scholarship. Cadden examines the discussions of sexual difference from Aristotle through the fourteenth century, revealing a wide range of ideas about sexual determination, reproductive roles and sexual pleasure. She finds multiple models of sexuality in writings throughout the middles ages. This challenged Thomas Laqueur's assertion in \"Making Sex: Body and Gender from the Greeks to Freud\" (1990) that male and female were seen as \"manifestations of a unified substratum\" before the 18th century. Cadden addressed medieval discourse in all its \"staggering complexity\", an \"interconnectedness of intellectual interests\" that was \"far from comforting\" in its diversity.\n",
"Informally, girls were faced with a knowledge void. Their elders did not share information with them. This silence led to the spreading of myths around women's sexuality, including that men were a representation of evil. As they grew older and closer to the age to marry, girls received more sexual education from friends, mothers, sisters, and future in-laws. The education explained the role of the husband. It also addressed the importance of a doctor for reproductive health. Largely though, young women were left to navigate in the dark, with little informal education. Few girls from economically disadvantaged families had access to texts that could provide them with additional information, not even in manuals designed for marriage preparation courses. For other parts of society, the use of marriage self-help books was common, and many people received their sex education from these. These marital guides about sex and conjugal rights were published for couples about to marry or recently married, providing information for men or women on sexual and reproductive health. They were written from a clinical perspective and amounted to self-help guides. They were intended to be read in the privacy of a person's home, correcting misinformation resulting from people not being able to discuss sexuality because it was culturally taboo. For upper-class men, sex education was generally informal and would often come from sex with prostitutes and with maids employed by their households.\n",
"According to Leah DeVun, a \"traditional Hippocratic/Galenic model of sexual difference – popularized by the late antique physician Galen and the ascendant theory for much of the Middle Ages – viewed sex as a spectrum that encompassed masculine men, feminine women, and many shades in between, including hermaphrodites, a perfect balance of male and female\". DeVun contrasts this with an Artistotelian view of intersex, which argued that \"hermaphrodites were not an intermediate sex but a case of doubled or superfluous genitals\", and this later influenced Aquinas.\n",
"Traditionally, adolescents in many cultures were not given any information on sexual matters, with the discussion of these issues being considered taboo. Such instruction, as was given, was traditionally left to a child's parents, and often this was put off until just before a child's marriage. The progressive education movement of the late 19th century, however, led to the introduction of \"social hygiene\" in North American school curricula and the advent of school-based sex education. Despite early inroads of school-based sex education, most of the information on sexual matters in the mid-20th century was obtained informally from friends and the media, and much of this information was deficient or of dubious value, especially during the period following puberty, when curiosity about sexual matters was the most acute. This deficiency was heightened by the increasing incidence of teenage pregnancies, particularly in Western countries after the 1960s. As part of each country's efforts to reduce such pregnancies, programs of sex education were introduced, initially over strong opposition from parent and religious groups.\n",
"Little is known of child sexuality before the Age of Enlightenment, but it is presumed (considering the number of servants needed to run great households and the simple design of ordinary homes) that many children would have observed sexual activity as a frequent and natural phenomenon. In the 19th century, with the arrival of industrialization and literacy, sexual repression appears to have become institutionalized and extra-marital activity generally criminalized to the point where newly married couples experienced difficulty in achieving consummation of their marriage.\n",
"In the 19th century, various women began to question the commonly accepted patriarchal interpretation of Christian scripture. One of the foremost of these was Sarah Grimké, who voiced skepticism about the ability of men to translate and interpret passages relating to the roles of the sexes without bias. She proposed alternative translations and interpretations of passages relating to women, and she applied historical and cultural criticism to a number of verses, arguing that their admonitions applied to specific historical situations, and were not to be viewed as universal commands.\n",
"\"The Dialectic of Sex\" is still used in many women's studies programs. Its recommendations, such as raising children in a gender neutral fashion, mirror the ideals Firestone set out to achieve in her heyday.\n"
] |
Is time dilation the same at every black-hole event horizon?
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Might I be able to also ask a question regarding black holes, their shape etc.?
From what I understand, there's a region on the edge of the event horizon is a photon sphere where photons moving on a tangent to this will become trapped in orbit.
However when I've seen pictures regarding black holes - particularly showing the 'corona' around the event horizon where light behind the hole is bending around it - it is shown as just that: a corona-like light with a void in the middle.
How can the photon sphere be just that - spherical - yet not actually show up as a mass of photons when viewed in xray /infra-red etc? Surely if these photons are in a sphere around the event horizon it would appear almost like a star, right?
|
[
"There are real phenomena that cause time dilation similar that of a stasis field. Extremely high velocities approaching light speed or immensely powerful gravitational fields such as those existing near the event horizons of black holes will cause time to progress more slowly. However, there is no known theoretical way of causing such time dilation independently of such conditions.\n",
"The increase in the time coordinate to infinity as one approaches the event horizon is why information could never be received back from any probe that is sent through such an event horizon. This is despite the fact that the probe itself can nonetheless travel past the horizon. It is also why the space-time metric of the black hole, when expressed in Schwarzschild coordinates, becomes singular at the horizon - and thereby fails to be able to fully chart the trajectory of an infalling probe.\n",
"When some probe (such as a light ray or an observer) approaches a black hole event horizon, its Schwarzschild time coordinate grows infinite. The outgoing null rays in this coordinate system have an infinite change in \"t\" on travelling out from the horizon. The tortoise coordinate is intended to grow infinite at the appropriate rate such as to cancel out this singular behaviour in coordinate systems constructed from it.\n",
"Also, in terms of physics, the term \"time horizon\" is also synonymous with event horizon, first identified in Stephen Hawking's A Brief History of Time. Hawking stated that the time horizon is the boundary that separates a black hole from other celestial bodies. Even time and light cannot escape once trapped in the black hole.\n",
"The time reversal of a black hole would be a hypothetical object known as a white hole. From the outside they appear similar. While a black hole has a beginning and is inescapable, a white hole has an ending and cannot be entered. The forward light-cones of a white hole are directed outward; and its backward light-cones are directed towards the center.\n",
"Stephen Hawking had shown earlier that the total horizon area of a collection of black holes always increases with time. The horizon is a boundary defined by light-like geodesics; it is those light rays that are just barely unable to escape. If neighboring geodesics start moving toward each other they eventually collide, at which point their extension is inside the black hole. So the geodesics are always moving apart, and the number of geodesics which generate the boundary, the area of the horizon, always increases. Hawking's result was called the second law of black hole thermodynamics, by analogy with the law of entropy increase, but at first, he did not take the analogy too seriously.\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"
] |
why is it so difficult for the medical community to give a straight answer about how much a procedure/appointment/etc. will cost?
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The doctors and nurses don't even *know* how much shit costs. They just say what work they've done & the billing department handles the prices.
Billing can't give you a straight answer because they have different rates for cash payments or insurance. Every insurance company negotiates a set of rates they'll pay for procedures but how much you're left paying depends on the terms of your insurance plan. Then, if you're poor, you might be able to negotiate an even *lower* price so the hospital can at least get *something* out of you.
The whole system is confusing and inefficient. Those inefficiencies only serve to drive costs up while making insurance companies rich. This is one of the many reasons that people think a single-payer system - where the government is the only insurer for everyone - would be superior.
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[
"The American Medical Association showed that asking simple single item questions, such as \"How confident are you in filling out medical forms by yourself?\", is a very effective and direct way to understand from a patient's point of view how they feel about interacting with their healthcare provider and understanding their health condition.\n",
"Physicians have difficulty explaining complicated medical concepts to their patients and patients have difficulty understanding complicated things which physicians tell them. One reasons for this is that a patient's visit to a physician is likely to be less than 15 minutes, and in any case, physicians are unable to spend the amount of time which patients that patients typically desire. Physicians use medical terms which patients do not understand, but which they would like to learn. There is consensus that patients should have shared decision making, which means that they make informed decisions about the direction of their health care in collaboration with their physician. Rich, educated, socially advantaged patients enjoy many more benefits of shared decision making than patients who have disadvantages in getting healthcare, including lower socioeconomic class or having a minority status.\n",
"It has been speculated and supported in data (from a report conducted in 1998) that the complete elimination of all waiting times is not ideal. When waiting lists arise through a prioritization process based on physician-determined medical urgency and the procedure's risk, (in contrast to patient's ability to pay or profitability for the physician), waiting lists can possibly help patients. It has been postulated that a system of immediate care can be detrimental for optimal patient outcomes, as unnecessary or unproven surgery might not be easily avoided if all patients are granted instant care.\n",
"An OR suite that puts up with excessive surgical times can schedule itself efficiently but still lose its financial shirt if many surgeons are slow, use too many instruments, or expensive implants, etc. These are all measured by the contribution margin per OR hr. The contribution margin per hour of OR time is the hospital revenue generated by a surgical case, less all the hospitalization variable labor and supply costs. Variable costs, such as implants, vary directly with the volume of cases performed.\n",
"Visits by specialist doctors or diagnostic tests are provided by the public hospitals or by conventional private ones, and if prescribed by the family doctor require only a copay (of the order of $40 for a visit without any diagnostic test) and are free for the poor. Waiting times are usually up to a few months in the big public facilities and up to a few weeks in the small conventional private facilities, though the referring doctor can shorten the waiting times of the more urgent cases by prioritising them. Patients, however, can opt for the \"free market\" option, provided by both public and private hospitals, which is paid completely out-of-pocket and has generally much shorter waiting times.\n",
"Several factors have been identified as contributing to its high performance, including its payment of doctors on a flat salary bais instead of fee-for-service (which tends to incentivize volume of care rather than quality); bundled payments for several common procedures (such as heart surgery and prenatal care) to shield patients and the system from paying for complications arising from the original service; establishing checklists of best practices for physicians to follow for specific conditions and procedures to ensure good outcomes for patients; and a robust electronic medical record system that minimizes duplication of treatments and tests. \n",
"Doctors perform surgery with the consent of the patient. Some patients are able to give better informed consent than others. Populations such as incarcerated persons, people living with dementia, the mentally incompetent, persons subject to coercion, and other people who are not able to make decisions with the same authority as a typical patient have special needs when making decisions about their personal healthcare, including surgery.\n"
] |
do programs like lumosity have any measurable benefit to cognitive abilities? or is it all just hype?
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Using Lumosity regularly makes you better at Lumosity. It might be of more benefit to your cognition than staring at a wall and picking your nose, but it's mostly hype and pseudoscience
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[
"Kable researches cognitive neuroscience. His work has suggested that an individual's approach to risk in decision making is correlated with the anatomical structure of the brain. Another of Kable's projects concluded that \"Brain Training\" using Lumosity software “appears to have no benefits in healthy young adults above those of standard video games.” Kable's team used functional magnetic resonance imaging (fMRI) to measure brain activation in the participants while they were performing executive function tasks. The measurements revealed no difference in brain activity between the Lumosity and control groups.\n",
"Several of Gazzaley's studies explore how cognitive abilities may be enhanced via engagement with custom designed video games, neurofeedback and TES. In 2009 he designed a video game, NeuroRacer, to enhance cognitive abilities of older adults. In a study published in 2013 as the cover story of Nature he showed that the multitasking nature of the game caused improvements in tasks outside of the game involving working memory and sustained attention.\n",
"Systolic arrays are therefore extremely good at artificial intelligence, image processing, pattern recognition, computer vision and other tasks which animal brains do so particularly well. Wavefront processors in general can also be very good at machine learning by implementing self configuring neural nets in hardware.\n",
"Systolic arrays are therefore extremely good at artificial intelligence, image processing, pattern recognition, computer vision and other tasks which animal brains do so particularly well. Wavefront processors in general can also be very good at machine learning by implementing self configuring neural nets in hardware.\n",
"fMRI and EEG studies have revealed that task difficulty is an important factor affecting neural efficiency. More intelligent individuals display neural efficiency only when faced with tasks of subjectively easy to moderate difficulty, while no neural efficiency can be found during difficult tasks. In fact, more able individuals appear to invest more cortical resources in tasks of high difficulty. This appears to be especially true for the Prefrontal Cortex, as individuals with higher intelligence displayed increased activation of this area during difficult tasks compared to individuals with lower intelligence. It has been proposed that the main reason for the neural efficiency phenomenon could be that individuals with high intelligence are better at blocking out interfering information than individuals with low intelligence.\n",
"A 2017 study examined the effect of HIIT on cognitive performance among a group of children (N=318). The authors show that HIIT is beneficial to cognitive control and working memory capacity when compared against \"a blend of board games, computer games, and trivia quizzes\" and that this effect is mediated by the BDNF polymorphism. They conclude that the study \"suggests a promising alternative to enhance cognition, via short and potent exercise regimens\".\n",
"It is the reverse of the ELIZA effect, which Sherry Turkle states is \"our more general tendency to treat responsive computer programs as more intelligent than they really are\": that is, anthropomorphism. \n"
] |
How was helium identified from the continuous spectrum of the sun?
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The sun's photosphere is cooler than the regions below it, creating absorption lines. If you point a spectrometer at the sun you don't get a continuous spectrum, you get a continuous spectrum superimposed with black lines where the particular wavelength was absorbed by the cooler upper atmosphere. Those absorption lines are in the exact place that emission lines are, so if we see absorption lines in the sun that we haven't been able to find a matching emission line then we know we have an element in the sun that we have yet to find and get emission lines for. Here is a picture of the whole visible wavelength spectrum of the sun _URL_0_
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[
"The first evidence of helium was observed on August 18, 1868, as a bright yellow line with a wavelength of 587.49 nanometers in the spectrum of the chromosphere of the Sun. The line was detected by French astronomer Jules Janssen during a total solar eclipse in Guntur, India. This line was initially assumed to be sodium. On October 20 of the same year, English astronomer, Norman Lockyer, observed a yellow line in the solar spectrum, which, he named the D because it was near the known D and D Fraunhofer line lines of sodium. He concluded that it was caused by an element in the Sun unknown on Earth. Lockyer and English chemist Edward Frankland named the element with the Greek word for the Sun, ἥλιος (\"helios\").\n",
"The published reports on the discovery of helium report, that helium was discovered by two scientists independently in 1868. French astronomer Jules Janssen observed helium emission lines on 18 August 1868 as a bright yellow line during a total solar eclipse in Guntur, India. On 20 October of the same year, English astronomer Norman Lockyer observed a yellow line in the solar spectrum. He took the observation in West Hampstead, United Kingdom.\n",
"Helium is named for the Greek Titan of the Sun, Helios. It was first detected as an unknown, yellow spectral line signature in sunlight, during a solar eclipse in 1868 by Georges Rayet, Captain C. T. Haig, Norman R. Pogson, and Lieutenant John Herschel, and was subsequently confirmed by French astronomer, Jules Janssen. Janssen is often jointly credited with detecting the element, along with Norman Lockyer. Janssen recorded the helium spectral line during the solar eclipse of 1868, while Lockyer observed it from Britain. Lockyer was the first to propose that the line was due to a new element, which he named. The formal discovery of the element was made in 1895 by two Swedish chemists, Per Teodor Cleve and Nils Abraham Langlet, who found helium emanating from the uranium ore, \"cleveite\". In 1903, large reserves of helium were found in natural gas fields in parts of the United States, which is by far the largest supplier of the gas today.\n",
"During early studies of the optical spectrum of the photosphere, some absorption lines were found that did not correspond to any chemical elements then known on Earth. In 1868, Norman Lockyer hypothesized that these absorption lines were caused by a new element that he dubbed \"helium\", after the Greek Sun god Helios. Twenty-five years later, helium was isolated on Earth.\n",
"The first known extreme helium star, HD 124448, was discovered in 1942 by Daniel M. Popper at the McDonald Observatory in Austin, Texas, USA. This star displayed no lines of hydrogen in its spectrum, but strong helium lines as well as the presence of carbon and oxygen. The second, PV Telescopii, was discovered in 1952, and by 1996 a total of 25 candidates had been found. (This list was narrowed to 21 by 2006.) A common characteristic of these stars is that the abundance ratio of carbon to helium is always in the range of 0.3 to 1%. This is despite wide variation of other abundance ratios in EHe stars.\n",
"BULLET::::- Helium: The French astronomer, Pierre Janssen observed the Solar eclipse of 18 August 1868 from Guntur in Madras State, British India. He discovered the first evidence of helium as a bright yellow line in the chromograph of the Sun\n",
"At first, it was hypothesized that the line might be due to an unknown element, which was named nebulium. A similar idea had led to the discovery of helium through analysis of the Sun's spectrum in 1868. While helium was isolated on Earth soon after its discovery in the spectrum of the Sun, \"nebulium\" was not. In the early 20th century, Henry Norris Russell proposed that, rather than being a new element, the line at 500.7 nm was due to a familiar element in unfamiliar conditions.\n"
] |
What would the ramifications of a lack of causality be?
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Unpredictability. The equations of motion lose existence and uniqueness. Given a certain initial condition at time t, there might not exist a solution to later time, or there might be infinite equally valid. Essentially the Universe doesn't know what to do with itself, and even if it does, there is no way of predicting anything even having knowledge of the equations of motion and initial condition. Physics is dead.
That loss of existence and uniqueness actually occurs has been studied for various cases, including the motion of a rigid ball in a spacetime with a wormhole allowing timetravel (see e.g. the works of Novikov & Thorne), or classical field theories in the presence of CTCs.
The exceptions are free theories, but these are boring, no actual physics can happen in them. As soon as you add interactions of any kind it's over.
Another sort of consideration comes from thermodynamics. We have a second law because our Universe has two temporal extremities with different entropies. So entropy increases when moving from one to the other; we call the low-entropy one the Big Bang and the direction of increasing entropy gives the arrow of time, and interesting stuff happens following the Universe in this direction.
If you have a region with CTCs where, say, you can think of time as a circle, there is no way of course for entropy to always increase in one direction. The most probable situation is to always have constant maximum entropy, that is thermal equilibrium.
|
[
"Causal determinism has a strong relationship with predictability. Perfect predictability implies strict determinism, but lack of predictability does not necessarily imply lack of determinism. Limitations on predictability could be caused by factors such as a lack of information or excessive complexity. \n",
"Some philosophers believe that causality may not exist if determinism is true, as causality is merely the observation that one event precedes another, or that there is a pattern throughout spacetime in which events of one similar type tend to correlate with events of another similar type (that is, the mass-energy distribution in spacetime has an information theoretic 'pattern' where car crashes tend to be correlated with injury, say). There may be no ultimate reason for why a chain of causality occurs the way that it does beyond the fact that a chain of causality exists. The fact that certain events seem to 'cause' other events is the recognition of a pattern in the structure of spacetime and the mass-energy that exists in spacetime, which is ultimately either due OR an instantiation of the laws of physics. Note: Stating that causality does not exist may be a bit misleading, as one would have to Define what is meant by 'causality' - it may be that causality is dependent upon counterfactual definiteness, that is, A causes B because, if A did NOT occur, then B would not occur (i.e.: A is necessary for B) AND because A is sufficient for B. It may be possible that causality is ultimately a meaningless concept (if one rejects counterfactual definiteness for instance), but that causal chains are still a valid concept (as they would merely be chains of events).\n",
"Causal reasoning may be activated almost automatically. However, inferences about cause and effect do not always demonstrate understanding of mechanisms underlying causality; causality has been described as \"cognitive illusion\". Much understanding of cause and effect is based on associations, without an understanding of how events are related to one another; this is known as the \"illusion of explanatory depth\".\n",
"Despite these subtleties, causality remains an important and valid concept in physical theories. For example, the notion that events can be ordered into causes and effects is necessary to prevent (or at least outline) causality paradoxes such as the grandfather paradox, which asks what happens if a time-traveler kills his own grandfather before he ever meets the time-traveler's grandmother. See also Chronology protection conjecture.\n",
"Causal oversimplification is a specific kind of false dilemma where conjoint possibilities are ignored. In other words, the possible causes are assumed to be \"A or B or C\" when \"A and B and C\" or \"A and B and not C\" (etc.) are not taken into consideration.\n",
"Causality, when defined expansively (as for instance in the \"mystic psychology\" book \"The Kybalion\", or in the platonic Kant-style Axiom of Causality), states that \"nothing can happen without being caused.\" Such an understanding of causality may be incompatible with synchronicity. Other definitions of causality (for example, the neo-Humean definition) are concerned only with the relation of cause to effect. As such, they are compatible with synchronicity. There are also opinions which hold that, where there is no external observable cause, the cause can be internal.\n",
"Philosophical efforts to understand causality extend back at least to Aristotle's discussions of the four causes. It was long considered that an effect preceding its cause is an inherent self-contradiction because, as 18th century philosopher David Hume discussed, when examining two related events, the cause, by definition, is the one that precedes the effect.\n"
] |
why do vodka sodas dehydrate me?
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The metabolism of alcohol requires the presence of water, and alcohol itself is a diuretic which results in less available water in your body.
Edit: To expand on this, the amount of water in your mixed drink is probably insufficient to hold off dehydration after your body has processed the alcohol. Everyone has an individual water requirement to maintain themselves. You may just not be reaching yours when you drink, and have to compensate by drinking more water in the morning.
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[
"In some countries, black-market or \"bathtub\" vodka is widespread because it can be produced easily and avoid taxation. However, severe poisoning, blindness, or death can occur as a result of dangerous industrial ethanol substitutes being added by black-market producers. In March 2007 in a documentary, BBC News UK sought to find the cause of severe jaundice among imbibers of a \"bathtub\" vodka in Russia. The cause was suspected to be an industrial disinfectant (Extrasept) – 95% ethanol but also containing a highly toxic chemical – added to the vodka by the illegal traders because of its high alcohol content and low price. Death toll estimates list at least 120 dead and more than 1,000 poisoned. The death toll is expected to rise due to the chronic nature of the cirrhosis that is causing the jaundice. However, there are also much higher estimates of the annual death toll (dozens or even hundreds of thousands of lives) produced by the vodka consumption in Russia.\n",
"Under Canadian regulations, Vodka is a potable alcoholic beverage created by treatment of grain spirit or potato spirit with charcoal, which renders the product without aroma, taste or distinctive character. \n",
"Vomiting excessive amounts of alcohol is an attempt by the body to prevent alcohol poisoning and death. Vomiting may also be caused by other drugs, such as opiates, or toxins found in some foods and plants. Food allergies and sensitivities, such as lactose intolerance, can cause vomiting.\n",
"The vodka's function is, ostensibly, to release flavors in the tomato that are normally inaccessible; using alcoholic beverages for this purpose is common in Italian cooking, although usually accomplished with wine. It is also an emulsifier, serving to keep the sauce stable, when normally the oil of the cream sauce would react with the acidic tomato sauce to separate from the water in both.\n",
"Vodka ( , ) is a clear distilled alcoholic beverage that originates from Poland and Russia. It is composed primarily of water and ethanol, but sometimes with traces of impurities and flavorings. Traditionally it is made by distilling the liquid from cereal grains or potatoes that have been fermented, though some modern brands use fruits or sugar as the base.\n",
"A vodka soda is a mix of one part vodka with about two parts or four parts club soda or naturally-flavored soda, served over large cubed ice in a highball glass, short tumbler, small cocktail glass. A squeeze of lemon or lime juice can also be added. Some variations of the vodka soda include cucumber and mint or raspberry and basil.\n",
"Metronidazole in combination with alcohol causes severe reactions such as vomiting and flushes in many patients. Tetracycline resorption is reduced by dairy products, antacids and other products containing calcium, magnesium, aluminium as well as iron.\n"
] |
why when running on a treadmill usually i'm really tired at 15 min mark, almost dead at 20 min, and ok at 30 min mark ?
|
It actually comes from where your body gets it's energy from. For the first 15-20 minutes your body is burning it's glycogen storage which comes from sugar. After your body has run out of its primary source of energy it runs on fumes until your body starts burning your fat storage. This doesn't kick in until around that 30 minute mark because your body has to turn that fat back into sugar for it to use which takes a while.
Source: avid runner for 10+ year and worked in a running store for almost 8 years and have had to explain this to people lots
|
[
"BULLET::::- Treadmill training – Many treadmills have programs set up that offer numerous different workout plans. One effective cardiovascular activity would be to switch between running and walking. Typically warm up first by walking and then switch off between walking for three minutes and running for three minutes.\n",
"BULLET::::- Some treadmill runners develop bad running habits that become apparent when they return to outdoor running. In particular a short, upright, bouncy gait may result from having no wind resistance and trying to avoid kicking the motor covering with the front of the foot.\n",
"Running on sand may result in slower times, approximately 30 seconds per mile more than the your usual pace, but others say the sand is easier than pavement running and great for long runs. In 2007, Stephen Baumgartner was the first runner to break the 3 hour mark finishing in 2 hours, 55 minutes, and 44 seconds.\n",
"In repeated sprints in hypoxia (RSH), athletes run short sprints under 30 seconds as fast as they can. They experience incomplete recoveries in hypoxic conditions. The exercise to rest time ratio is less than 1:4, which means for every 30 second all out sprint, there is less than 120 seconds of rest.\n",
"After the Wainwrights run, Birkinshaw suffered health problems diagnosed as chronic fatigue syndrome, saying in an article in \"Fell Runner\" in 2017 that he \"is not sure if he is fully recovered. 'Sometimes I have days when I feel completely normal. Other days I have some \"brain fog\" but it is nowhere near as bad as it was. ... I have done some longer harder runs and sometimes I have felt OK and sometimes I have really struggled. Basically I am happy with where I am. I might recover fully and be able to push it as hard and be as fast as before, but I might never get there. However, I can live a normal life and go out running every day.' \" In July 2018 he accompanied Kilian Jornet on a section of his record-breaking Bob Graham Round (Jornet completed in 12 hours 52 minutes, an hour below the previous record) and reported that \"although I have recovered from my Wainwrights round – which is now four years ago – I am still five to ten per cent slower than I was then.\"\n",
"Runners must train hard, because running on sand is very demanding on the human body. A difficult portion of the race is Hvide Sande, the sand here feels like deep snow. The timelimit for the marathon is 7 hours.\n",
"Tempo runs are typically run for 20 to 25 minutes at a 6 or 7 RPE. This exercise is “like an Oreo cookie, with the warmup and cooldown as the cookie, and a run at an effort at or slightly above your anaerobic threshold (the place where your body shifts to using more glycogen for energy) as the filling.\" What runners do here is warm up at a slow and steady pace, then run harder than they would on a normal distance jog for an allotted amount of time, and then do a cool down with a very similar speed to the warm up. \n"
] |
where did the term "fired" originate from?
|
[Etymology Online](_URL_0_) says it is recorded by 1885 (with out; 1887 alone) in American English. This probably is a play on the two meanings of discharge (v.): "to dismiss from a position," and "to fire a gun," influenced by the earlier general sense "throw (someone) out" of some place (1871). To fire out "drive out by or as if by fire" (1520s) is in Shakespeare and Chapman. Fired up "angry" is from 1824 (to fire up "become angry" is from 1798).
|
[
"The term \"feu\" (French for \"fire\" from the Latin \"focus\" meaning \"hearth\") meant, especially in the Middle Ages, the hearth, first in the strict sense (the place where the fire burns) and figuratively: the family home (cf. the expression \"without fire or place\") or the family itself. Very quickly, it was used as the basic unit for assessment, calculation, and collection of tax and it was called the \"feu fiscal\" meaning \"fire tax\".\n",
"Fire arrows were one of the earliest forms of weaponized gunpowder, being used from the 9th century onward. Not to be confused with earlier incendiary arrow projectiles, the fire arrow was a gunpowder weapon which receives its name from the translated Chinese term \"huǒjiàn\" (火箭), which literally means fire arrow. In China a 'fire arrow' referred to a gunpowder projectile consisting of a bag of incendiary gunpowder attached to the shaft of an arrow. Fire arrows are the predecessors of fire lances, the first firearm.\n",
"The English verb to \"burn\", attested since the 12th century, is a combination of Old Norse \"brenna\" \"to burn, light\", and two originally distinct Old English verbs: \"bærnan\" \"to kindle\" (transitive) and \"beornan\" \"to be on fire\" (intransitive), both from the Proto-Germanic root \"bren(wanan)\", perhaps from a Proto-Indo-European root \"bhre-n-u\", from base root \"bhereu-\" \"to boil forth, well up.\" In Dutch, \"(ver)branden\" mean \"to burn\", \"brandmerk\" a branded mark; similarly, in German, \"Brandzeichen\" means \"a brand\" and \"brandmarken\", \"to brand\".\n",
"The term \"firedog\" seems to arise from the perceived similarity of an andiron to a dog lying by the fire. In English, however, this form may also have been influenced by French: another French term for an andiron is \"chenet\", which originally meant 'little dog'.\n",
"The term \"flaming\" may originate from \"The Hacker's Dictionary\", which in 1983 defined it as \"\"to speak rabidly or incessantly on an uninteresting topic or with a patently ridiculous attitude\"\". The meaning of the word has diverged from this definition since then.\n",
"Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition.\n",
"BULLET::::- Fire arrow: One of the earliest weaponized forms of gunpowder was the fire arrow which received its name from the translated Chinese term \"huǒjiàn\" (火箭), which literally means fire arrow. In China a 'fire arrow' referred to a gunpowder projectile consisting of a bag of incendiary gunpowder attached to the shaft of an arrow from the 9th century onward. Later on solid fuel rockets utilizing gunpowder were used to provide arrows with propulsive force and the term \"fire arrow\" became synonymous with rockets in the Chinese language. In other languages such as Sanskrit 'fire arrow' (\"agni astra\") underwent a different semantic shift and became synonymous with 'cannon.' Fire arrows are the predecessors of fire lances, the first firearm.\n"
] |
What rank would a soldier have to be to avoid going 'over the top' in WWI?
|
That's a very interesting question, and relates a lot to a common perception that, once a certain level of authority is reached, the individual is less likely to participate in combat.
That is a very generalised view, of course, and as such not entirely correct. An army is a very rigid organization and must be tightly controlled and led. The closer that leadership is to the fighting, the more effective it can be. The balance, of course is to not expose high ranking leadership to the dangers of the front unnecessarily. Also, the larger formation one commands would dictate having to be further removed from the front on the basis of the scale of numbers a Division, Corps or Army commander would be dealing with.
There also lies a difference in the role of particular persons-what is known as "the Divisional Wedge"- which describes the ratio of those engaged in combat to those supporting combat operations. A Lt Col as a battalion commander would very likely advance with his men, while a Lieutenant assigned to General Headquarters might not ever hear a shot fired in anger. Likewise for NCO's. A farrier Corporal would be well removed from fighting, performing his job of shoeing horses, whilst a Sergeant in an infantry platoon would certainly see his fair share of the war.
Maj Gordon Corrigan illustrates that even high rank did not exempt one from the dangers of the war: "Altogether four British lieutenant generals, twelve major generals and eighty-one brigadier generals died or were killed between 1914-1918. A further 146 were wounded or taken prisoner. Whatever else the generals were doing, they were certainly not sitting in comfortable chateaux." *Mud, Blood and Poppycock* Cassell Press, 2003.
|
[
"BULLET::::- Many of the generals of World War I had experience in combat, but only from the days before trench warfare became widespread. Because of this, officers lacked the experience that in the past had made it viable to command troops from a distance.\n",
"During World War II, he served in the Royal Artillery, Royal Army Ordnance Corps, and Royal Electrical and Mechanical Engineers. He enlisted as a private (neglecting to inform the military about his degrees) but eventually reached the rank of major.\n",
"He was promoted to major during World War I and was commanding officer of the 2nd Battalion of the Bedfordshire Regiment, where at Festubert on 17 May 1915, when leading his men, he was killed just after he had left the jumping off trench.\n",
"During World War II, Cliff was commissioned as an officer in the United States Army. He served in the European theater, in the Third and Ninth Armies, earning four battle stars and a Bronze Star Medal with an oak leaf cluster. By the war's end, he was discharged as a lieutenant colonel.\n",
"Part of the problem was the Army's promotion system, which continued to cause problems into World War II. The rank a Regular Army officer might hold, and their official rank were not always the same. Thus a \"peacetime rank\" and a \"wartime\" rank differed. An officer might start the war as a lieutenant colonel, end the war as a major general, and then revert to being a lieutenant colonel after the war. Incidentally, pay was not necessarily tied to rank, but depended on time in service and an individuals official rank. In the small Regular Army of 1917, most officers were below the rank of colonel, and few serving in general officer billets actually were recognized by Congress as holding the rank of general, rather, they were \"breveted\" to the higher rank. Actual promotion required Congressional approval, the number of positions limited by law, and was based solely on seniority. Breveting allowed the Army to bypass these restrictions, for better or worse. Thus, the problem of promoting Sibert to brigadier general in the Engineer Corps and the subsequent trouble it caused.\n",
"During World War I in Britain, the minimum height for soldiers was . Thus thousands of men under this height were denied the ability to fight in the war. As a result of pressure to allow them entry, special \"Bantam Battalions\" were created composed of men who were to . By the end of the war there were 29 Bantam Battalions of about 1,000 men each. Officers were of normal size.\n",
"During World War I he served initially with the 80th Field Artillery Regiment, and then was a student at the U.S. Army Field Artillery School at Fort Sill, Oklahoma, where he was received promotion to the temporary rank of major but saw no service overseas as the war came to an end on November 11, 1918.\n"
] |
how do some people become the mod of dozens of subreddits?
|
You'd have to ask the people who made the decision to add them, we don't know. The thought process for each individual mod invite was probably different.
I'm not sure but it's also possible that they did stuff like CSS work. There are some people who do design and CSS stuff for lots of subreddits so they have mod powers, but they don't actually moderate much. We had /u/gavin19 on our staff here for a while while he helped us out with some stuff, for example, and we could have left him on if we wanted even though he never did any moddy work.
|
[
"Subreddits are overseen by moderators, Reddit users who earn the title by creating a subreddit or being promoted by a current moderator. These moderators are volunteers who manage their communities, set and enforce community-specific rules, remove posts and comments that violate these rules, and generally work to keep discussions in their subreddit on topic. Admins, by contrast, are paid to work for Reddit.\n",
"Mods take both an active position in forums by acting as the corporate client to provide services, as well as passively looking through the end user experience to monitor social media and quality assurance testing. In active mode, Mods moderate content, chat with customers, manage communities, protect child safety (approved by Safe Kids USA), monitor game experience, provide customer support, check for bugs, and manage social media accounts. Using a variety of Customer Relations Management systems, Mods work from anywhere in the world with secure internet access, enabling native-language services to be provided in 50+ languages and dialects during peak traffic and activity hours.\n",
"ModSquad is a global digital engagement services company based in the United States. The company currently has over 10,000 moderators in its network. ModSquad provides managed, on-demand customer service, content moderation, social media, and community management services and teams across online, e-commerce, in-game, in-app, and social media channels.\n",
"A subcontractor is a company or person who is hired by a general contractor (or prime contractor, or main contractor) to perform a specific task as part of the overall project and is normally paid for services provided to the project by the originating general contractor. While the most common concept of a subcontractor is in building works and civil engineering, the range of opportunities for subcontractor is much wider and it is possible that the greatest number now operate in the information technology and information sectors of business.\n",
"ModSpot is the main lobby area for \"ModNation Racers\". Players can meet up, race, and create and download content. The ModSpot contains Race Station which has Online Race, Quick Race, Split-Screen and Career (Story Mode), Creation Station, where players create their Mods, Karts and Tracks, and also share and shop points, Top Mods, Top Karts and Top Tracks, Coming Attractions to view upcoming DLC, Hot Lap where players can try to earn the best times on a track and a News Update screen. Players can start chats using text, voice or gestures.\n",
"Mods can be both useful to players and a means of self-expression. Three motivations have been identified by Olli for fans to create mods: to patch the game, to express themselves, and to get a foot in the door of the video game industry. However, it is very rare for even popular modders to make this leap to the professional video game industry. Poor suggests becoming a professional is not a major motivation of modders, noting that they tend to have a strong sense of community, and that older modders, who may already have established careers, are less motivated by the possibility of becoming professional than younger modders.\n",
"The purpose of Mod DB is to list the mods, files, tutorials and information of any games that are capable of being modded with user-made content. Community involvement is strongly encouraged, and any game mod with a website is allowed to post a screenshot gallery, news, and requests for help. Scott's intentions, from the beginning, were to get the community heavily involved in the creation and development of the website. To this end, the most active members were chosen as moderators and administrators. The core staff generally remain the same, while lower positions are heavily rotated among trainee moderators, and administrator candidates. The site's staff mostly act as chaperones or librarians, keeping appropriate content available to the public and featuring the more exceptional content.\n"
] |
What was the video-recording format in the USSR/Ex-socialist countries ? Was there an equivalent to VHS ?
|
I'm not an expert on The Soviet Union but I have a strong interest in and experience with tech. So a Soviet expert may be able to add a lot to the discussion. But to quickly answer your main question, the main format used popularly in the USSR was VHS and the VCR.
There were other forms of magnetic recording devices used mostly by professionals but I don't know much about them. You seem most interested in personal use though.
According to several US news articles the machines first appeared by being brought back by those who had travelled to the West. Demand for the devices began to grow and video parlors had opened by 1985 using the VHS format.
Here's a [link](_URL_0_) to a book called "Split Signals" by Ellen Propper Mickiewicz.
This book was published in 1988 and she wrote about television in the USSR during this time and has a section just on VCR production and usage. Highlighted is a reference to the Elektronika VM-12 which was one of the first Soviet produced VCRs.
Electronika is a brand name used to describe consumer products created by Soviet military industrial engineers. It's still in use today in Belarus. Although according to Mickiewicz the VM-12 was produced in Voronezh a Russian city south of Moscow.
Unfortunately I'm unaware of the ability of these Soviet produced machines to record as well as playback. The way Mickiewicz describes the machines it seems like the government wanted to be able to control what was available and supplant a growing black market for video watching with approved materials.
Links to contemporary news articles:
*[Chicago Tribune](_URL_1_) Discusses early use and has some pretty slanted views on Vodka vs Video as a hobby.
*[LA Times](_URL_2_) Discusses copy protection and privacy.
*[Baltimore Sun](_URL_3_) Written by a Soviet immigrant to America, it has an interesting personal perspective on the format and the exchange of culture it allowed.
|
[
"The first video cassette recorder (VCR) to become available was the U-matic system, released in September 1971. U-matic was designed for commercial or professional television production use, and was not affordable or user-friendly for home videos or home movies. The first consumer-grade VCR to be released was the Philips N1500 VCR format in 1972, followed in 1975 by Sony's Betamax. This was quickly followed by the competing VHS format from JVC, and later by Video 2000 from Philips. Subsequently, the Betamax–VHS format war began in earnest. Other competitors, such as the Avco Cartrivision, Sanyo's V-Cord and Matsushita's \"Great Time Machine\" quickly disappeared.\n",
"Compact Video Cassette (CVC) was one of the first analog recording videocassette formats to use a tape smaller than its earlier predecessors of VHS and Betamax, and was developed by Funai Electronics of Japan for portable use. The first model of VCR for the format was the Model 212, introduced in 1980 by both Funai and Technicolor as they had created a joint venture to manufacture and introduce the format to the home movie market. The system, which included the VCR and a hand held video camera, was very small and lightweight for its time.\n",
"VHS (short for Video Home System) is a standard for consumer-level analog video recording on tape cassettes. Developed by Victor Company of Japan (JVC) in the early 1970s, it was released in Japan on September 9, 1976 and in the United States on August 23, 1977.\n",
"Video Cassette Recording (VCR) is an early domestic analog recording format designed by Philips. It was the first successful consumer-level home videocassette recorder (VCR) system. Later variants included the VCR-LP and Super Video (SVR) formats.\n",
"Although Video8 acquired a digital variant, Digital8, D-VHS was never adapted to a compact format, as the consumer camcorder industry moved on to small-format MiniDV tapes, then hard-drive- and DVD-based machines, and then solid-state storage.\n",
"Video 2000 (also known as V2000, with the tape standard Video Compact Cassette, or VCC) is a consumer videocassette system and analogue recording standard developed by Philips and Grundig to compete with JVC's VHS and Sony's Betamax video technologies. Designed for the PAL colour television standard (some models additionally handled SECAM), distribution of Video 2000 products began in 1979 exclusively in Europe, South Africa and Argentina and ended in 1988.\n",
"The videotape format war was a period of intense competition or \"format war\" of incompatible models of consumer-level analog video videocassette and video cassette recorders (VCR) in the late 1970s and the 1980s, mainly involving the Betamax and Video Home System (VHS) formats. VHS ultimately emerged as the preeminent format.\n"
] |
; why can't they just give the 12 boys and the football coach who were found in the cave in thailand oxygen masks so they can swim out? why do they need to teach them to dive or wait for the flood to recede?
|
There's a lot more to diving than just putting on a mask and swimming. For example, if one of the boys gets scared and holds his breath, then ascends, his lungs could rupture quite easily. They need to make sure that the boys can dive safely before they can use that as an escape method.
|
[
"On 23 June 2018, a group of twelve boys aged between 11 and 16, who went to explore Tham Luang Nang Non with their assistant football coach, aged 25, went missing. The group was found 10 days later. They were part of a local junior football team. The cave they entered became flooded. Thai Navy SEAL divers had been searching the caves ever since. Owing to heavy rain which further flooded the cave entrance, searches were periodically interrupted. Thai NAVY divers soon got help from American, Australian, British, and Chinese divers, military members, and emergency personnel.\n",
"In June and July 2018, a widely publicised cave rescue successfully extricated members of a junior football team trapped in Tham Luang Nang Non cave in Chiang Rai Province, Thailand. Twelve members of the team, aged eleven to sixteen, and their 25-year-old assistant coach entered the cave on 23 June after football practice. Shortly afterwards, heavy rains partially flooded the cave, trapping the group inside.\n",
"In 2018, twelve boys aged 11 to 16, all members of a junior association football team, and their 25-year-old male assistant coach were stranded in the cave for 18 days by a flood. They were rescued in a massive joint operation between the Thai government, the Thai military, and a group of international expert cave divers. British divers found them on a muddy ledge in darkness more than from the entrance nine days into their ordeal. The effort to save their lives was a global operation watched around the world. In all, 90 divers – 50 of whom were foreigners – helped to extract the group. An ex-navy diver, Saman Kunan, died during the mission because he ran out of air, having placed air tanks along the route to the boys.\n",
"4 July: The team was taught how to use a full face diving mask and breathing apparatus as none of the boys knew how to swim. Rescue teams worked on continuing to pumping water from the cave, they had already pumped out over 30 million gallons.\n",
"The local people and many Myanmar pilgrims enjoyed having a good swim at the entrance of the cave. The swallow water flows and cascade from the 600m deep cave. In turns, many locals from Pyin Oo Lwin develop shops with some local products such as wine and dried meat (satt tar chuak) and souvenirs to suit for visitors.\n",
"In June 2018 Harris was about to depart on a cave diving holiday to the Nullabor Plain when he and dive partner Craig Challen were requested by the Thai government, on the advice of British cave diving experts attempting to rescue twelve Thai children and their soccer coach who were trapped in the Tham Luang Nang Non cave system, to provide assistance with the rescue efforts.\n",
"They are not allowed to play with any kind of breathing apparatus during competitive play. However, some practice with scuba tanks. Majority of the players, who are called apnea divers, freedive often and have prepared accordingly.\n"
] |
- why is it so hard for companies doing political surveys to actually predict the elections?
|
Really? The _vast_ majority of polling is very accurate - we just only pay attention to it in the few situations where the polling was "wrong".
Polling is difficult because you are trying to take a small sample of people and extrapolate what you learn from them to a population as a whole. Ensuring that the sample is representative of the population is tricky, as is making sure that you get honest answers from those people.
Reputable pollsters work very hard to try to eliminate bias in their questions and their samples to make the results as accurate as possible, but they know that anytime you sample you won't get perfect results. That is why they also publish confidence intervals and margins of error - how accurate they feel the polling to be.
|
[
"In politics it is common to attempt to predict the outcome of elections via political forecasting techniques (or assess the popularity of politicians) through the use of opinion polls. Prediction games have been used by many corporations and governments to learn about the most likely outcome of future events.\n",
"Academic scholars have constructed models of voting behavior to forecast the outcomes of elections. These forecasts are derived from theories and empirical evidence about what matters to voters when they make electoral choices. The forecast models typically rely on a few predictors in highly aggregated form, with an emphasis on phenomena that change in the short-run, such as the state of the economy, so as to offer maximum leverage for predicting the result of a specific election.\n",
"A group of researchers at Wellesley College examined data from Google Trends and analyzed how effective a tool it could be in predicting U.S. Congressional elections in 2008 and 2010. In highly contested races where data for both candidates were available, the data successfully predicted the outcome in 33.3% of cases in 2008 and 39% in 2010. The authors conclude that, compared to the traditional methods of election forecasting, incumbency and New York Times polls, and even in comparison with random chance, Google Trends did not prove to be a good predictor of either the 2008 or 2010 elections. Another group has also explored possible implications for financial markets and suggested possible ways to combine insights from Google Trends with other concepts in technical analysis.\n",
"Everything from macroeconomic, microeconomic, market data from the future, machine-learning (artificial neural networks), and human behavioral studies have all been used to achieve better forecasts. Forecasts are used for a variety of purposes. Governments and businesses use economic forecasts to help them determine their strategy, multi-year plans, and budgets for the upcoming year. Stock market analysts use forecasts to help them estimate the valuation of a company and its stock.\n",
"With the advent of statistical techniques, electoral data have become increasingly easy to handle. It is no surprise, then, that election forecasting has become a big business, for polling firms, news organizations, and betting markets as well as academic students of politics.\n",
"The administering of public opinion polls for the 2009 presidential election was beset by numerous difficulties because of the lack of security, harsh geography, and lack of accurate demographic data, but analysts hoped that with improved sampling techniques the pre-election polls would be more predictive of the outcome than they were in 2004.\n",
"Surowiecki discusses the success of prediction markets. Similar to Delphi methods but unlike opinion polls, prediction (information) markets ask questions like, \"Who do you think will win the election?\" and predict outcomes rather well. Answers to the question, \"Who will you vote for?\" are not as predictive.\n"
] |
why is human diet so complex?
|
A big part is just convienece and choice. Animals with "higher" capacity for reason can figure out optimal ways to get food and therefore the option to be picky.
Most animals don't have the range primarily because they're both evolved to live in a certain area and they have a lower count of things that they're required to to on a day to day basis.
Most animals can be lumped into predator/prey and have diets that fit their lifestyle and activities accordingly.
Other animals, like our cousins the chimp which fall into both and have a wider range of day to day activities and behaviors, actually do have a pretty diverse diet. They eat lots of plants but they also eat eggs, honey, meat, etc.
Humans don't really "NEED" a diverse diet. We just choose to have one.
|
[
"Humans are omnivorous, capable of consuming a wide variety of plant and animal material. Varying with available food sources in regions of habitation, and also varying with cultural and religious norms, human groups have adopted a range of diets, from purely vegan to primarily carnivorous. In some cases, dietary restrictions in humans can lead to deficiency diseases; however, stable human groups have adapted to many dietary patterns through both genetic specialization and cultural conventions to use nutritionally balanced food sources. The human diet is prominently reflected in human culture, and has led to the development of food science.\n",
"The digestive abilities of anatomically modern humans, however, are different from those of pre-\"H. s. sapiens\" humans, which has been used to criticize the diet's core premise. During the 2.6 million year-long Paleolithic era, the highly variable climate and worldwide spread of human populations meant that humans were, by necessity, nutritionally adaptable. Supporters of the diet mistakenly presuppose that human digestion has remained essentially unchanged over time.\n",
"The evolutionary discordance is incomplete, since it is based mainly on the genetic understanding of the human diet and a unique model of human ancestral diets, without taking into account the flexibility and variability of the human dietary behaviors over time. Studies of a variety of populations around the world show that humans can live healthily with a wide variety of diets and that humans have evolved to be flexible eaters. Lactose tolerance is an example of how some humans have adapted to the introduction of dairy into their diet. While the introduction of grains, dairy, and legumes during the Neolithic revolution may have had some adverse effects on modern humans, if humans had not been nutritionally adaptable, these technological developments would have been dropped.\n",
"Due to the variety of environments inhabited, physiologies of the humans and human ancestors alive during the Paleolithic over 2.8 million years, we can’t ascribe a single set diet to any species, regional or cultural group. Increasing amounts of animal protein is viewed by some scientists as essential to the evolution of a larger human brain. Larger brain sizes required a greater caloric intake and the shift from earlier hominins is viewed as a generally greater reliance and shift to more animal protein (Aiello 2009). Meat eating was undoubtedly a factor in the increase in human brain size, but its importance in human diet cannot be assumed across all times and places, and is heavily dependent on the local environment. In colder climates meat might be necessary due to the decreased availability of plant based foods, and in hotter tropical climates a wider range of plants would be available.\n",
"Many specifics of the evolution of the human diet change regularly as new research and lines of evidence become available. Through the Paleolithic across the last 2.8 million years there has been a pattern of human and human ancestor’s biology adapting to an additionally available food source with resulting greater brain size, with the subsequent broadening and diversification of human diet. \"Homo habilis\" incorporated larger amounts of animal protein and fat into its diet, then as \"Homo erectus\" evolved it increased the breadth of its diet through fire and more advanced tool use. \"Homo sapiens\" in turn evolved the ability to consume cooked starch and marine life, which led to a further increase in brain size then greater technological diversification that ultimately allowed modern humans to adapt to a wide variety of ecological niches. The initial technological and biological adaptations each have knock on effects that allow a greater range of species to be used as food. This culminates in the Neolithic when suites of plants and animals are ultimately domesticated. In short, if there is a clear universal human Paleolithic diet, it is the use of fire to cook food.\n",
"Diet is an important area of study for bioarchaeologists because it can reveal many aspects of an individual and the population. The types of foods that were produced and eaten can yield information on how society was structured, on various settlement patterns, and on how healthy or unhealthy the population was.\n",
"Humans and other animals need a minimum intake of food energy to sustain their metabolism and to drive their muscles. Foods are composed chiefly of carbohydrates, fats, proteins, water, vitamins, and minerals. Carbohydrates, fats, proteins, and water represent virtually all the weight of food, with vitamins and minerals making up only a small percentage of the weight. (Carbohydrates, fats, and proteins comprise ninety percent of the dry weight of foods.) Organisms derive food energy from carbohydrates, fats and proteins as well as from organic acids, polyols, and ethanol present in the diet. Some diet components that provide little or no food energy, such as water, minerals, vitamins, cholesterol and insoluble fiber, may still be necessary to health and survival for other reasons. Water, minerals, vitamins, and cholesterol are not broken down (they are used by the body in the form in which they are absorbed) and so cannot be used for energy. Fiber cannot be completely digested by most animals, including humans, who can only extract 2 kcal/g of food energy. Ruminants can extract nearly 4 kcal/g from fiber because of the bacteria in their rumens.\n"
] |
What killed off the mega fauna?
|
Traditionally this has been ascribed either to the influence of humans on the environment or climate change, although occasionally disease has been tossed around as a hypothesis. Lately, many scientists have been siding with the climate change view.
[This study suggests otherwise.](_URL_0_) It would appear from global analysis of extinctions of megafauna over time that while most of these species had already survived numerous climatic shifts at the time of their demise, nearly all coincided with the earliest evidence of human presence in the area. It seems no accident that (large-bodied) mammoths survived later in North America, and were extinct within a few thousand years of humans reaching the continent.
Remember that most of the species that died off, the 'megafauna' were large creatures with metabolisms that required large amounts of food and had slow gestation and growth rates. Driving them to extinction by hunting wouldn't have required killing every single one, only enough to reduce the population by a little bit each year. The populations would have been particularly devastated if too many females were killed, as we see with modern day elephant populations. Also, the presence of a large population of humans foraging and gathering edible plant material might have reduced the amount of nutrition available to the animals, although I don't know if they would have been enough to have an impact on that or even ate the same vegetation. Certainly a systematic, if slow, reduction of the prey populations would have resulted in a decrease of large predators like dire wolves and cave lions, which probably suited the early humans just fine.
Another thing to note is that the extinction probably didn't happen very quickly. There would never have been a generation that saw the megafauna disappear. There would have been fewer and fewer mammoths each generation, until finally only grandpa remembered having seen one. The mammoths weren't literally all being slaughtered, they were just having more and more trouble finding mates and being able to maintain a sustainable population.
Hope that helps a bit. I'm not an expert on the topic, although I do follow it closely and know a fair bit about it. I've heard evidence supporting both cases and while I see this one as more likely, I don't deny that climate change may well and probably did add to the decrease in megafauna populations.
Interesting fact: the only continent with a diversity of sustainable megafauna populations is Africa, the continent on which humans evolved... Currently, biodiversity of large mammals is at a critical low, thanks to the Pleistocene extinctions. Ecosystems like the Siberian tundra and the American west are barely sustainable because of the absence of the megafauna that were once part of that equilibrium. At least I have read this several times, someone might be able to elaborate or correct me on that.
Edit: you tagged your question as biology, but it might be more accurately tagged as paleontology. I know the paleontology tag doesn't appear in the sidebar, but there is one!
|
[
"During the American megafaunal extinction event around 12,700YBP, 90genera of mammals weighing over became extinct. The extinction of the large carnivores and scavengers is thought to have been caused by the extinction of the megaherbivore prey upon which they depended. The cause of the extinction of the megafauna is debated but has been attributed to the impact of climate change, competition with other species including overexploitation by newly arrived human hunters, or a combination of both. One study proposes that several extinction models should be investigated because so little is known about the biogeography of the dire wolf and its potential competitors and prey, nor how all these species interacted and responded to the environmental changes that occurred at the time of extinction.\n",
"Mammalian megafauna once widespread in the MPA was driven to near extinction in the early 20th century. Some species have been successfully recovered since then — the population of white rhinoceros (\"Ceratotherium simum simum\") increased from less than 20 individuals in 1895 to more than 17,000 as of 2013. Other species are still dependent of fenced areas and management programs, including black rhinoceros (\"Diceros bicornis minor\"), African wild dog (\"Lycaon pictus\"), cheetah (\"Acynonix junatus\"), elephant (\"Loxodonta africana\"), and lion (\"Panthera leo\").\n",
"Continuing human hunting and environmental disturbance has led to additional megafaunal extinctions in the recent past, and has created a serious danger of further extinctions in the near future (see examples below). Direct killing by humans, primarily for meat, is the most significant factor in contemporary megafaunal decline.\n",
"The loss of species from ecological communities, defaunation, is primarily driven by human activity. This has resulted in empty forests, ecological communities depleted of large vertebrates. In the Quaternary extinction event, the mass die-off of megafaunal variety coincided with the appearance of humans, suggesting a human influence. One hypothesis is that humans hunted large mammals, such as the woolly mammoth, into extinction. The 2019 \"Global Assessment Report on Biodiversity and Ecosystem Services\" by IPBES states that the total biomass of wild mammals has declined by 82 percent since the beginning of human civilization.\n",
"Two main theories propose a cause for megafauna extinction - human impact and climate change. A study has been performed in which more than 700 \"Genyornis\" eggshell fragments were dated. Through this, it was determined that \"Genyornis\" declined and became extinct over a short period—too short for it to be plausibly explained by climate change. The authors considered this to be a very good indication that the entire mass extinction event in Australia was due to human activity, rather than climate change. A 2015 study collected egg shell fragments of \"Genyornis\" from around 200 sites that show burn marks. Analysis of amino acids in the egg shells showed a thermal gradient consistent with the egg being placed on an ember fire. The egg shells were dated to between 53.9 and 43.4 thousand years before present, suggesting that humans were collecting and cooking Genyornis eggs in the thousands of years before their extinction. A later study, however, suggests that the eggs actually belonged to the giant malleefowl, a species of extinct megapode.\n",
"There has been a debate as to the extent to which the disappearance of megafauna at the end of the last glacial period can be attributed to human activities by hunting, or even by slaughter of prey populations. Discoveries at Monte Verde in South America and at Meadowcroft Rock Shelter in Pennsylvania have caused a controversy regarding the Clovis culture. There likely would have been human settlements prior to the Clovis Culture, and the history of humans in the Americas may extend back many thousands of years before the Clovis culture. The amount of correlation between human arrival and megafauna extinction is still being debated: for example, in Wrangel Island in Siberia the extinction of dwarf woolly mammoths (approximately 2000 BCE) did not coincide with the arrival of humans, nor did megafaunal mass extinction on the South American continent, although it has been suggested climate changes induced by anthropogenic effects elsewhere in the world may have contributed.\n",
"Megafauna were once found on every continent of the world and large islands such as New Zealand and Madagascar, but are now almost exclusively found on the continent of Africa, with notable comparisons on Australia and the islands previously mentioned experiencing population crashes and trophic cascades shortly after the earliest human settlers. It has been suggested that the African megafauna survived because they evolved alongside humans. The timing of South American megafaunal extinction appears to precede human arrival, although the possibility that human activity at the time impacted the global climate enough to cause such an extinction has been suggested.\n"
] |
ip addresses, subnet masks and why some ip addresses can see others on the same network?
|
An IPv4 address is just 4 bytes; each number between the dots is in a range of 0 to 255.
Take 192.168.60.1
In binary that's 11000000.10101000.00111100.00000001.
Now take a subnet like 255.255.224.0
In binary that's 11111111.11111111.11110000.00000000
Notice how all of the bits are together? The part of the address that identifies the network are where the ones are. The part that describes the address on the network are where the zeros are. This is why it's called a subnet [mask](_URL_0_)
So, with our previous example
11000000.10101000.00111100.00000001 - IPv4 Address
11111111.11111111.11110000.00000000 - Subnet mask
11000000.10101000.00110000.00000000 - Network part (192.168.48.0)
00000000.00000000.00001100.00000001 - Node address of node on network
|
[
"Today, IP addresses are associated with a subnet mask. This was not required in a classful network because the mask was implied by the address itself; Any network device would inspect the first few bits of the IP address to determine the class of the address and thus its netmask.\n",
"The term \"subnet mask\" is only used within IPv4. Both IP versions however use the CIDR concept and notation. In this, the IP address is followed by a slash and the number (in decimal) of bits used for the network part, also called the \"routing prefix\". For example, an IPv4 address and its subnet mask may be and , respectively. The CIDR notation for the same IP address and subnet is , because the first 24 bits of the IP address indicate the network and subnet.\n",
"An IPv4 subnet mask consists of 32 bits; it is a sequence of ones (\"1\") followed by a block of zeros (\"0\"). The ones indicate bits in the address used for the network prefix and the trailing block of zeros designates that part as being the host identifier.\n",
"A network address is an identifier for a node or host on a telecommunications network. Network addresses are designed to be unique identifiers across the network, although some networks allow for local, private addresses or locally administered addresses that may not be unique. Special network addresses are allocated as broadcast or multicast addresses. These too are not unique.\n",
"Multiple client devices can appear to share an IP address, either because they are part of a shared hosting web server environment or because an IPv4 network address translator (NAT) or proxy server acts as an intermediary agent on behalf of the client, in which case the real originating IP address might be masked from the server receiving a request. A common practice is to have a NAT mask a large number of devices in a private network. Only the \"outside\" interface(s) of the NAT needs to have an Internet-routable address.\n",
"There is an exception to this rule for 31-bit subnet masks, which means the host identifier is only one bit long for two permissible addresses. In such networks, usually point-to-point links, only two hosts (the end points) may be connected and a specification of network and broadcast addresses is not necessary.\n",
"For IPv4, a network may also be characterized by its subnet mask or netmask, which is the bitmask that when applied by a bitwise AND operation to any IP address in the network, yields the routing prefix. Subnet masks are also expressed in dot-decimal notation like an address. For example, is the subnet mask for the prefix .\n"
] |
When accelerating close to c, the universe appears to contract. We see the universe as expanding. Is it possible that this is some related phenomenon and that the universe isn't actually expanding?
|
No, these are two different phenomena (which are, by the way, both accounted for in the mathematics, so aren't being mistaken for one another!). Two observers who are moving at different speeds will measure lengths differently - this is what you're referring to with contraction - but there's no such set-up in cosmology, we're essentially at rest (in our own reference frame) and watching galaxies and galaxy clusters move away from us in all directions.
|
[
"Since the Hubble \"constant\" is a constant only in space, not in time, the radius of the Hubble sphere may increase or decrease over various time intervals. The subscript '0' indicates the value of the Hubble constant today. Current evidence suggests that the expansion of the universe is accelerating (\"see\" Accelerating universe), meaning that, for any given galaxy, the recession velocity dD/dt is increasing over time as the galaxy moves to greater and greater distances; however, the Hubble parameter is actually thought to be decreasing with time, meaning that if we were to look at some \"fixed\" distance D and watch a series of different galaxies pass that distance, later galaxies would pass that distance at a smaller velocity than earlier ones.\n",
"Hubble provided evidence that the recessional velocity of a galaxy increases with its distance from the Earth, a property now known as \"Hubble's law\", despite the fact that it had been both proposed and demonstrated observationally two years earlier by Georges Lemaître. Hubble-Lemaître's Law implies that the universe is expanding. A decade before, the American astronomer Vesto Slipher had provided the first evidence that the light from many of these nebulae was strongly red-shifted, indicative of high recession velocities.\n",
"Another common source of confusion is that the accelerating universe does \"not\" imply that the Hubble parameter is actually increasing with time; since formula_21, in most accelerating models formula_22 increases relatively faster than formula_23, so H decreases with time. (The recession velocity of one chosen galaxy does increase, but different galaxies passing a sphere of fixed radius cross the sphere more slowly at later times.)\n",
"Cosmologists estimate that the acceleration began roughly 5 billion years ago. Before that, it is thought that the expansion was decelerating, due to the attractive influence of matter. The density of dark matter in an expanding universe decreases more quickly than dark energy, and eventually the dark energy dominates. Specifically, when the volume of the universe doubles, the density of dark matter is halved, but the density of dark energy is nearly unchanged (it is exactly constant in the case of a cosmological constant).\n",
"Current evidence suggests that the expansion rate of the universe is accelerating, which means that the second derivative of the scale factor formula_23 is positive, or equivalently that the first derivative formula_24 is increasing over time. This also implies that any given galaxy recedes from us with increasing speed over time, i.e. for that galaxy formula_25 is increasing with time. In contrast, the Hubble parameter seems to be decreasing with time, meaning that if we were to look at some fixed distance d and watch a series of different galaxies pass that distance, later galaxies would pass that distance at a smaller velocity than earlier ones.\n",
"The accelerating expansion of the universe is the observation that the expansion of the universe is such that the velocity at which a distant galaxy is receding from the observer is continuously increasing with time.\n",
"To determine if the expansion rate of the universe is speeding up or slowing down over time, cosmologists make use of the finite velocity of light. It takes billions of years for light from a distant galaxy to reach the Earth. Since the universe is expanding, the universe was smaller (galaxies were closer together) when light from distant galaxies was emitted. If the expansion rate of the universe is speeding up due to dark energy, then the size of the universe increases more rapidly with time than if the expansion were slowing down. Using supernovae, we cannot quite measure the size of the universe versus time. Instead we can measure the size of the universe (at the time the star exploded) and the distance to the supernova. With the distance to the exploding supernova in hand, astronomers can use the value of the speed of light along with the theory of General Relativity to determine how long it took the light to reach the Earth. This then tells them the age of the universe when the supernova exploded.\n"
] |
is space observation in real time?
|
everything you see is delayed. you seeing the sun is 8 minutes delayed. you watching the moon is 1.3seconds delayed. you looking at jupiter yesterday was 35-52minutes delayed. you looking at the North star 323 YEARS delayed. when you look thru a telescope at andromeda galaxy, you're looking 2.25 million years delayed
you reading this text on the screen is 0.0000000001 seconds delayed from when the computer monitor first displayed it.
|
[
"In each reference frame, an observer can use a local coordinate system (usually Cartesian coordinates in this context) to measure lengths, and a clock to measure time intervals. An event is something that happens at a point in space at an instant of time, or more formally a point in spacetime. The transformations connect the space and time coordinates of an event as measured by an observer in each frame.\n",
"One rationale behind the connection between time and space is that space is an easier concept to understand than time. Space is three dimensional and can be perceived directly using visual sensors, that is, we can physically see a space. In contrast time is one dimensional and can only be perceived indirectly, for example, by seeing that a person has aged, we can infer that time has passed however we do not physically see time. There are many other examples of spatial representations of time around the world such as clocks, calendars and hourglasses. \n",
"The concept of observing a subject from different points in space and time simultaneously (multiple or mobile perspective) \"\"to seize it from several successive appearances, which fused into a single image, reconstitute in time\"\" developed by Metzinger (in his article, \"Cubisme et tradition\", Paris Journal, 16 August 1911) and observed in \"La Femme au Cheval\" was not derived from Albert Einstein's theory of relativity, though it was certainly influenced in a similar way, through the work of Jules Henri Poincaré (particularly Science and Hypothesis). Poincaré's writings, unlike Einstein's, were well known leading up to 1912. Poincaré's widely read book, \"La Science et l'Hypothèse\", was published in 1902 (by Flammarion).\n",
"Experimental physicist Hartmut Grote of the Max Planck Institute in Germany states that although he is skeptical that the apparatus will successfully detect the holographic fluctuations, if the experiment is successful \"it would be a very strong impact to one of the most open questions in fundamental physics. It would be the first proof that space-time, the fabric of the universe, is quantized.\"\n",
"When making observations, scientists look through telescopes, study images on electronic screens, record meter readings, and so on. Generally, on a basic level, they can agree on what they see, e.g., the thermometer shows 37.9 degrees C. But, if these scientists have different ideas about the theories that have been developed to explain these basic observations, they may disagree about what they are observing. For example, before Albert Einstein's general theory of relativity, observers would have likely interpreted an image of the Einstein cross as five different objects in space. In light of that theory, however, astronomers will tell you that there are actually only two objects, one in the center and four different images of a second object around the sides. Alternatively, if other scientists suspect that something is wrong with the telescope and only one object is actually being observed, they are operating under yet another theory. Observations that cannot be separated from theoretical interpretation are said to be theory-laden.\n",
"Special relativity statements involving an \"observer\" are in some measure articulating a similar kind of impersonal relative direction. An \"observer\" is a \"perspective\" in that it is a context from which events in other inertial reference frames are evaluated but it is not the sort of perspective that a single particular person would have: it is not localized and it is not associated with a particular point in space, but rather with an entire inertial reference frame that may exist anywhere in the universe (given certain lengthy mathematical specifications and caveats.)\n",
"In a further development in his 1908 \"Space and Time\" lecture, Minkowski gave an alternative formulation of this idea that used a real time coordinate instead of an imaginary one, representing the four variables of space and time in coordinate form in a four dimensional real vector space. Points in this space correspond to events in spacetime. In this space, there is a defined light-cone associated with each point, and events not on the light-cone are classified by their relation to the apex as \"spacelike\" or \"timelike\". It is principally this view of spacetime that is current nowadays, although the older view involving imaginary time has also influenced special relativity.\n"
] |
Are there any cells in the human body that don't need oxygen?
|
Red blood cells! It actually makes quite a bit of sense, because red blood cells exist in order to transport oxygen, and if they required oxygen, they would be much less efficient in that endeavor.
|
[
"Oxygen is needed by almost all organisms for the purpose of generating ATP. It is also a key component of most other biological compounds, such as water, amino acids and DNA. Human blood contains a large amount of oxygen. Human bones contain 28% oxygen. Human tissue contains 16% oxygen. A typical 70-kilogram human contains 43 kilograms of oxygen, mostly in the form of water.\n",
"Nano sized oxygen carriers are used as a type of red blood cell substitutes, although they lack other components of red blood cells. They are composed of a synthetic polymersome or an artificial membrane surrounding purified animal, human or recombinant hemoglobin.\n",
"Since Ward & Brownlee's assertion that \"there is irrefutable evidence that oxygen is a necessary ingredient for animal life\", anaerobic metazoa have been found that indeed do metabolise without oxygen. Spinoloricus nov. sp., for example, a species discovered in the hypersaline anoxic L'Atalante basin at the bottom of the Mediterranean Sea in 2010, appears to metabolise with hydrogen, lacking mitochondria and instead using hydrogenosomes. Stevenson (2015) has proposed other membrane alternatives for complex life in worlds without oxygen. In 2017, scientists from the NASA Astrobiology Institute discovered the necessary chemical preconditions for the formation of azotosomes on Saturn's moon Titan, a world that lacks atmospheric oxygen. Independent studies by Schirrmeister and by Mills concluded that Earth's multicellular life existed prior to the Great Oxygenation Event, not as a consequence of it.\n",
"Lanza showed that it is feasible to generate functional oxygen-carrying red blood cells from human embryonic stem cells under conditions suitable for clinical scale-up. The blood cells could potentially serve as a source of \"universal\" blood.\n",
"One source of reactive oxygen under normal conditions in humans is the leakage of activated oxygen from mitochondria during oxidative phosphorylation. However, \"E. coli\" mutants that lack an active electron transport chain produced as much hydrogen peroxide as wild-type cells, indicating that other enzymes contribute the bulk of oxidants in these organisms. One possibility is that multiple redox-active flavoproteins all contribute a small portion to the overall production of oxidants under normal conditions.\n",
"In vertebrates, oxygen is taken into the body by the tissues of the lungs, and passed to the red blood cells in the bloodstream. Oxygen is then distributed to all of the tissues in the body and offloaded from the red blood cells to respiring cells. Hemoglobin then picks up carbon dioxide to be returned to the lungs. Thus, hemoglobin binds and offloads both oxygen and carbon dioxide at the appropriate tissues, serving to deliver the oxygen needed for cellular metabolism and removing the resulting waste product, CO.\n",
"In many invertebrates, these oxygen-carrying proteins are freely soluble in the blood; in vertebrates they are contained in specialized red blood cells, allowing for a higher concentration of respiratory pigments without increasing viscosity or damaging blood filtering organs like the kidneys.\n"
] |
What were the different techniques used for making swords across different cultures and time periods?
|
You're not the only one who loves swords! I was just saying the other day how much I miss the old *Highlander* TV series, but anyway... here's my quick round-up of posts discussing sword-making techniques. If anyone remembers any more, add the link as a reply & we'll create an entry in the "popular questions" wiki. - thx!
[How quickly did swords become too blunt to be effective during battle?](_URL_6_) (probably my all-time favourite post)
[what is the most effective sword/swordsmithing process that history has seen?](_URL_4_)
[Did any nation/culture even begin to approach the level of sword-making of Japan?](_URL_0_)
[What would be the primary differences between a cheap sword and an expensive sword, taking into account different time periods and methods of manufacture?](_URL_3_)
[Thursday Focus | Weaponry](_URL_1_)
[I just watched a NOVA episode on Ulfberht viking swords. There doesn't seem to be much about them elsewhere. Does anyone know a bit more about them, and maybe others like Ingelrii swords?](_URL_5_)
[Armor and/or weapon making resources? (Books, webpages, documentaries, articles?)](_URL_2_)
|
[
"Italian martial arts is the use of weapons (swords, daggers, walking stick and staff). Each weapon is the product of a specific historical era. The swords used in Italian martial arts range from the gladius of the Roman legionaries to swords which were developed during the renaissance, the baroque era and later. Short blades range from medieval daggers to the liccasapuni Sicilian duelling knife.\n",
"The art of sword making falls under the tradition of \"garzo\" (or blacksmithing), an art form that is used to make all metal implements such as swords, knives, chains, darts and so forth. Ceremonial swords are made and gifted to people who are honoured for their achievements. These swords are to be sported by men on all special occasions. Children, wear a traditional short knife known as the \"dudzom\". Terton Pema Lingpa, a religious treasure hunter from central Bhutan, was the most famous sword maker in Bhutan.\n",
"The development of Japanese swordsmanship as a component system of classical bujutsu created by and for professional warriors (bushi), begins only with the invention and widespread use of the Japanese sword, the curved, single-cutting-edged long sword.\n",
"Early Japanese iron-working techniques date back to the 3rd to 2nd century BCE. Japanese swordsmithing is of extremely high quality and greatly valued. These swords originated before the 1st century BCE and reached their height of popularity as the chief possession of warlords and \"samurai\". The production of a sword has retained something of the religious quality it once had in symbolizing the soul of the samurai and the martial spirit of Japan.Swordsmithing is considered a separate art form and moved beyond the craft it once started out as. \n",
"\"Native Sword Methods\" (K. \"Bon Kuk Geom Beop\" - 본국검법) is first identified in Korean legends of the Kingdom of Silla, one of the domains comprising \"The Three Kingdoms\" Period (37 BCE – 660 AD). The \"Yuji Sungnam\" relates a story of a seven-year-old boy from the Silla Kingdom who traveled across the Kingdom of Paekshe, demonstrating his \"sword dance\" (\"gummu\") and drawing large crowds. However, when finally summoned to perform his dance before the king, the boy ended his performance by plunging his sword into the king, killing him, and was, in turn, cut down by the king's retainers. In honor of the young boy's sacrifice, the Silla people created a masked sword dance resembling the boy's face.\n",
"The concept of wooden practice weapons is not limited to the historical european martial arts. Some Japanese martial arts involving swordsmanship, such as kenjutsu and iaido, use bokken or shinai as practice weapons. Eskrima, a martial art from the Philippines, also uses a type of rattan stick as a practice weapon in place of a blade. The martial art of singlestick is more or less entirely derived from the use of wasters as practice weapons in place of broadswords.\n",
"The swordsmiths of China are often credited with the forging technology that was carried to Korea and Japan, allowing swordsmiths in those places to create such weapons as the \"katana\". This technology included folding, inserting alloys, and differential hardening of the edge, which historically has been the most common technique around the world. While the Japanese would be more influenced by the Chinese \"dāo\" (single-edged swords of various forms), the early Japanese swords known as \"ken\" are often based on the \"jian\". One-sided \"jians\" from the Tang dynasty provided the basis for various Japanese forging styles and techniques. The Korean version of the \"jian\" is known as the \"geom\" or \"gum\", and these swords often preserve features found in Ming-era \"jian\", such as openwork pommels and sharply angled tips.\n"
] |
why do cities restrict the maximum height of structures?
|
There's quite a few reasons.
* Higher buildings mean a denser downtown core, causing greater traffic and possibly pollution issues as people come to work from bedroom communities and search for a place to park. So unless you have good public transport (which can be quite expensive to build if not in place already), concentrating things too much can be problematic.
* They block light and create major wind tunnels.
* They can go against the character of the place they're in. For example, some Caribbean island residents want to retain their island's quaintness and don't want to turn it into a mass of forty-story condo buildings so they have a "palm tree maximum height" rule.
* They can be more prone to safety problems like life-taking fires (e.g. 9-11) or earthquake response.
* The ground underneath them might not be suitably strong enough.
|
[
"Building height: 2.5 m (8' +/-) to 7.5 m (24' +/-) is common. Height is primarily limited by the capability of the wall panel to support the wind load. Height may be limited in narrow buildings due to shear capacity limit in the gable endwalls.\n",
"Among the restrictions in force within the zone is a ban on the construction of any structure exceeding in height, and that any new building which is located adjacent to a historically important structure must not exceed the height of the latter.\n",
"Height restriction laws sometimes become a point of contention in cities due to their use in regulating the growth of the housing supply. Fast growth of housing supply benefits renters by producing low prices and a lot of choice, while slow or no growth in housing supply benefits property owners by allowing them to charge higher prices. In this way, height restriction laws often become part of a class conflict even when their original purpose was innocuous.\n",
"Montreal places height-limits on skyscrapers so that they do not exceed the height of Mount Royal. The city forbids any building from reaching an elevation higher than or 223 metres above mean sea level. Above-ground height is further limited in most areas and only a few downtown land plots are allowed to exceed 120 metres in height. The limit is currently attained by 1000 de La Gauchetière and 1250 René-Lévesque, the latter of which is shorter, but built on higher ground. The only way to reach higher than 1000 de La Gauchetière while respecting this limit would be to build on the lowest part of downtown near Tour de la Bourse; the maximum height there would be approximately 210 metres.\n",
"Ultimately, though, it would not be height limits \"per se\" that restricted skyscrapers, but comprehensive zoning laws which would set up separate requirements for different parts of a city, and would regulate not only height, but also a building's volume, the percentage of the lot used, and the amount of light the building blocked, and would also encourage setbacks to reduce a building's bulk by allowing additional height per foot of setback – the exact amount depending on what zone the building was in. New York City was the first to do this, with the 1916 Zoning Resolution, which was prompted in good part by the construction of the Equitable Building in 1915, a 40-story building with straight sides and no setbacks, which raised fears of the downtown area becoming a maze of dark streets that never saw the sun. What was worse, at least to real estate interests, the building dumped 1.2 million square feet (111,000 m) of office space on what was a sluggish real estate market. To many in the real estate industry, the zoning law was an example of a \"reasonable restriction.\" \n",
"The Council on Tall Buildings and Urban Habitat defines skyscrapers as those buildings which reach or exceed in height. Others in the United States and Europe also draw the lower limit of a skyscraper at . \n",
"The first height limit ordinance in Los Angeles was enacted following the completion of the 13-story Continental Building, located at the southeast corner of Fourth and Spring streets. The purpose of the height limit was to limit the density of the city. There was great hostility to skyscrapers in many cities in these years, mainly due to the congestion they could bring to the streets, and height limit ordinances were a common way of dealing with the problem. In 1911, the city passed an updated height limit ordinance, establishing a specific limit of . Exceptions were granted for decorative towers such as those later built on the Eastern Columbia Building and United Artists Theatre, as well as the now-demolished Richfield Tower.\n"
] |
why are the soles of our feet so sensitive if they’re the main (and often only) point of contact with the ground?
|
Most likely because you wear shoes which keep your feet baby soft.
My kids go barefoot a lot and can walk across gravel without a problem.
|
[
"The soles of the feet are extremely sensitive to touch due to a high concentration of nerve endings, with as many as 200,000 per sole. This makes them sensitive to surfaces that are walked on, ticklish and some people find them to be erogenous zones.\n",
"The sole is a sensory organ by which we can perceive the ground while standing and walking. The subcutaneous tissue in the sole has adapted to deal with the high local compressive forces on the heel and the ball (between the toes and the arch) by developing a system of \"pressure chambers.\" Each chamber is composed of internal fibrofatty tissue covered by external collagen connective tissue. The septa (internal walls) of these chambers are permeated by numerous blood vessels, making the sole one of the most vascularized, or blood-enriched, regions in the human body.\n",
"As the skin texture under the soles of the feet can naturally endure high levels of strain, injuries demanding medical attention, such as lacerations or bruises, are rarely inflicted if certain precautions are observed by the executant. The undersides of the feet have therefore become a common target for corporal punishment in many cultures while basically different methods exist.\n",
"Friction ridge skin present on the soles of the feet and toes (plantar surfaces) is as unique in its ridge detail as are the fingers and palms (palmar surfaces). When recovered at crime scenes or on items of evidence, sole and toe impressions can be used in the same manner as finger and palm prints to effect identifications. Footprint (toe and sole friction ridge skin) evidence has been admitted in courts in the United States since 1934.\n",
"Patients with painful disorders of sensation (dysesthesia) of the soles of the feet may have a similar gait but do not have foot drop. Because of the extreme pain evoked by even the slightest pressure on the feet, the patient walks as if walking barefoot on hot sand.\n",
"Providing contact to the ground, the foot provides shock absorption and stability during stance. Additionally it influences gait biomechanics by its shape and stiffness. This is because the trajectory of the center of pressure (COP) and the angle of the ground reaction forces is determined by the shape and stiffness of the foot and needs to match the subject's build in order to produce a normal gait pattern. Andrysek (2010) found 16 different types of feet, with greatly varying results concerning durability and biomechanics. The main problem found in current feet is durability, endurance ranging from 16–32 months These results are for adults and will probably be worse for children due to higher activity levels and scale effects. Evidence comparing different types of feet and ankle prosthetic devices is not strong enough to determine if one mechanism of ankle/foot is superior to another. When deciding on a device, the cost of the device, a person's functional need, and the availability of a particular device should be considered.\n",
"Due to their position and function, feet are exposed to a variety of potential infections and injuries, including athlete's foot, bunions, ingrown toenails, Morton's neuroma, plantar fasciitis, plantar warts and stress fractures. In addition, there are several genetic disorders that can affect the shape and function of the feet, including a club foot or flat feet.\n"
] |
Did 13th century English knights fight on foot?
|
This answer focuses on the Anglo-Norman period, so earlier than the 13th century. But since OP was interested in English knights fighting on foot before the 14th century, I guess this will still be of interest.
In "Warfare under the Anglo-Norman Kings 1066-1135", Stephen Morrillo argues that combined arms tactics was central to many battles in this period, and also points out that sometimes dismounted knights played the part of the heavy infantry. In particular, dismounted knights appear in the Battle of Tinchebrai (1106), the Battle of Brémule (1119) and the Battle of Bourgthérolde (1124), although often along mounted knights and other infantry. Although the example of three battles seems to be quite small, considering the fact that battles were rare in this period (Morillo counts 7 battles, C. W. Hollister counts 5 battles of significance), this actually accounts for a significant number of Anglo-Norman battles.
So why did this dismounting occur? A knight on horseback can easily retreat, while a knight on foot has less chance of escaping a rout unharmed. Forced into this situation, a dismounted knight must either conquer or die. Indeed, this is often the reason given in the sources for the dismounting of knights. Dismounting has a psychological effect, helping to counteract the fear of harm and death that pervaded every battlefield. In particular, having the knights, the military elite, join the battle lines on foot seems to have been massively encouraging to the common infantry as well. Leaders would often be part of the dismounted to further boost morale. For example, King Henry I seemed to have been on foot in the Battle of Tinchebrai and Brémule, and at Bourgthérolde, Odo Borleng was dismounted with the knights under his command. In this case, dismounting can be done to reinforce and stiffen an existing infantry line, instead of making up the entire infantry line themselves.
As for how the Anglo-Norman army was able to put this into practice, Morillo argues that it stems from the relatively more centralized nature of Anglo-Norman government. He argues that the superiority of medieval cavalry actually stems from the inferior quality of medieval infantry, which requires cohesion brought about by a strong military tradition and/or professional training, both of which were hard to provide in medieval Western Europe. However, due to the more centralized nature of the Anglo-Norman realm and the professionalism of the Famillia Regis (the king's household), there was a strong core force of knights who could function as effective heavy infantry when dismounted.
On the other hand, in the article "Battles in England and Normandy, 1066-1154", Jim Bradbury argues that the dismounting of knights wasn't unique to the Anglo-Normans, but was in fact common in Western Europe. He cites several earlier examples of dismounted knights (such as the Battle of the Dyle in 891) and argues that it grew out of ordinary Frankish tactics, as part of the combined arms response (along with archers and mounted knights) to the threat of a cavalry charge.
This suggests that the practice of dismounting was not uncommon amongst English knights before the 14th century, an might not even be unique to the English. Dismounting was done as part of a wider combined arms battle plan, and deliberately organised. In these cases, the knights would've fought on foot even when not knocked off their horse, since their horse might not even be on the battlefield to begin with.
Sources:
* Stephan Morillo, Warfare under the Anglo-Norman Kings 1066-1135
* Stephan Morillo, [The "Age of Cavalry" Revisited](_URL_0_)
* Jim Bradbury, Battles in England and Normandy, 1066-1154 (Part of "Anglo-Norman Warfare", edited by Matthew Strickland)
|
[
"Many knights during Medieval battles fought on foot. Attacks would be carried out on horseback only under favorable conditions. If the enemy infantry was equipped with polearms and fought in tight formations it was not possible to charge without heavy losses. A fairly common solution to this was for the men-at-arms to dismount and assault the enemy on foot, such as the way Scottish knights dismounted to stiffen the infantry \"schiltron\" or the English combination of longbowmen with dismounted men-at-arms in the Hundred Years' War. Another possibility was to bluff an attack, but turn around before impact. This tempted many infantrymen to go on the chase, leaving their formation. The heavy cavalry then turned around again in this new situation and rode down the scattered infantry. Such a tactic was deployed in the Battle of Hastings (1066).\n",
"According to the chroniclers, it was the foot soldiers who won the day. The knights, fighting on foot, were immobile and vulnerable. The battle swayed to and fro for several hours, and resembled a massacre. Henry caught an axe blow to the helmet in the initial phase of the battle, and had to be supported from the field; but later returned to fight with undiminished vigour.\n",
"In medieval times the foot soldiers varied from peasant levies to semi-permanent companies of mercenaries, foremost among them the Swiss, English, Aragonese and German, to men-at-arms who went into battle as well-armoured as knights, the latter of which at times also fought on foot.\n",
"In peacetime, knights often demonstrated their martial skills in tournaments, which usually took place on the grounds of a castle. Knights can parade their armour and banner to the whole court as the tournament commenced. Medieval tournaments were made up of martial sports called \"hastiludes\", and were not only a major spectator sport but also played as a real combat simulation. It usually ended with many knights either injured or even killed. One contest was a free-for-all battle called a \"melee\", where large groups of knights numbering hundreds assembled and fought one another, and the last knight standing was the winner. The most popular and romanticized contest for knights was the \"joust\". In this competition, two knights charge each other with blunt wooden lances in an effort to break their lance on the opponent's head or body or unhorse them completely. The loser in these tournaments had to turn his armour and horse over to the victor. The last day was filled with feasting, dancing and minstrel singing.\n",
"During the early Tudor rule in England, some knights still fought for honour and for the good, to protect women and the poor while some others ignored the ethos. There were fewer knights engaged in active warfare because battlefields during this century were generally the area of professional infantrymen, with less opportunity for knights to show chivalry. It was the beginning of the demise of the knight. The rank of knight never faded, but it was Queen Elizabeth I who ended the tradition that any knight could create another and made it exclusively the preserve of the monarch. Christopher Wilkins contends that Sir Edward Woodville, who rode from battle to battle across Europe and died in 1488 in Brittany, was the last knight errant who witnessed the fall of the Age of Chivalry and the rise of modern European warfare. When the Middle Ages were over, the code of chivalry was gone.\n",
"He and two other English knights challenged three French knights to a tourney in the marches between Boulogne and Calais ; and on 20 June 1390 he procured a safe-conduct through England for William de Douglas, who was coming to the English court with forty knights to a wager of battle with Clifford with reference to certain disputed lands.\n",
"At Valdevez, the primary combatants on both sides were mounted knights. It is unclear how the battle developed, but it is believed that in order to eliminate the possibility of a mêlée, each monarch selected knights for individual jousting matches, and the battle descended into a hastilude. The need to deal with an Almoravid invasion of the south of his territory may have forced Afonso of Portugal to accept a tournament. Valdevez exemplifies the tendency, noted by Philippe Contamine, of medieval battles between knights to descend \"into a sort of great tourney, half serious, half frivolous.\" At Arcos de Valdevez many prisoners were taken but few lives lost. Besides Ramiro Fróilaz, who is the only nobleman taken at Valdevez mentioned by name in the contemporary \"Chronica Adefonsi imperatoris\", the Portuguese may have captured Ponce Giraldo de Cabrera and the Traba brothers Fernando Pérez and Bermudo Pérez. The Portuguese succeeded in gaining the advantage, by the laws of chivalry of the time, and defeated the Leonese knights. Under these circumstances a peace was concluded and prisoners exchanged. An armistice was signed after the battle that eventually became the Treaty of Zamora.\n"
] |
how is a modern minted coin ever worth more than its face value, isn't that exactly what money is a guarantee that you money will be what it says it's worth?
|
....an official currency coinage is only ever worth exactly its face value.
are you thinking about those tv commercials for gold clad coins? those coins are produced by a company named National Mint or something stupid like that. those are collector scams. they're not worth anything.
|
[
"Coins of the United States dollar (aside from those of the earlier Continental currency) were first minted in 1792. New coins have been produced annually and they make up a valuable aspect of the United States currency system. Today, circulating coins exist in denominations of 1¢ (i.e. 1 cent or $0.01), 5¢, 10¢, 25¢, 50¢, and $1.00. Also minted are bullion (including gold, silver and platinum) and commemorative coins. All of these are produced by the United States Mint. The coins are then sold to Federal Reserve Banks which in turn are responsible for putting coins into circulation and withdrawing them as demanded by the country's economy.\n",
"When the Z$500 million mint was commissioned by President Robert Mugabe, it was argued that it would save the country US$50 million in foreign currency because it was costing the country 150 cents to import a 10-cent piece, for example.\n",
"The coins were struck in August 1925 in San Francisco, and were sold the following month. They did not sell as well as hoped: only some 150,000 of the authorized mintage of 300,000 were ever struck, and of that, nearly half went unsold and were melted. The coin is catalogued at between $200 and $1,300, though exceptional specimens have sold for more.\n",
"For most of history, coins were valued based on the precious metal they contain. Whether a coin was actually made by the party as claimed was of secondary importance compared to whether it contains the correct amount of metal – that is, correct weight and fineness (purity). Genuine appearance was simply a convenient shortcut to avoid time-consuming tests in everyday transactions.\n",
"A total of 25,000 coins were minted in March 1937 in at the Philadelphia Mint and were sold by the Commission at $1.75 per piece, a relatively high issue price for the time. Of the 25,000 coins minted, 20,978 were sold, with the 4,022 remaining pieces returned to the mint for melting.\n",
"With the mass production of currency, the production cost is weighed when minting coins. For example, it costs the United States Mint much less than 25 cents to make a quarter (a 25 cent coin), and the difference in production cost and face value (called seigniorage) helps fund the minting body. Conversely, a U.S. penny ($0.01) cost $0.015 to make in 2016.\n",
"The 1804 dollar is one of the rarest and most famous coins in the world. Its creation was the result of a simple bookkeeping error, but its status as a highly prized rarity has been established for nearly a century and a half. The silver dollars reported by the mint as being struck in 1804 were actually dated 1803. (With die steel being very expensive in the early 19th century, dies were used until they were no longer in working condition. This is why many early U.S. coins exhibit various kinds of die cracks, occlusions, cuds, clash marks, and other late-state die wear. Nearly every coin the U.S. struck from 1793 to 1825 has an example that was struck in a year other than that which it bears.) No dollars bearing the date 1804 were ever struck in 1804, though this was unknown to mint officials at the time the 1804 dollar came to be.\n"
] |
In what year and battle did the last recorded charge of knights in heavy armor occur? What conflict last saw widespread use of knights in heavy armor?
|
If you by "knights" mean armoured cavalry consisting solely of noblemen, then the charge of the Polish crown army consisting of mostly [Polish winged hussars](_URL_0_), although they had stopped wearing the wings at that time, in the Battle of [Kliszow 1702](_URL_1_). The Polish cavalry threw the Swedish cavalry into disorder and then charged the Swedish infantry twice, but was repulsed both times. The Swedish cavalry then attacked and drove the Poles from the field.
|
[
"One of the greatest distinguishing marks of the knightly class was the flying of coloured banners, to display power and to distinguish knights in battle and in tournaments. Knights are generally \"armigerous\" (bearing a coat of arms), and indeed they played an essential role in the development of heraldry. As heavier armour, including enlarged shields and enclosed helmets, developed in the Middle Ages, the need for marks of identification arose, and with coloured shields and surcoats, coat armoury was born. Armourial rolls were created to record the knights of various regions or those who participated in various tournaments.\n",
"From the 11th to 14th centuries when medieval jousting was still practised in connection to the use of the lance in warfare, armour evolved from mail (with a solid, heavy helmet, called a \"great helm\", and shield) to plate armour. By 1400, knights wore full suits of plate armour, called a \"harness\" (Clephan 28-29).\n",
"On Rhodes the Hospitallers, by then also referred to as the Knights of Rhodes, were forced to become a more militarised force, fighting especially with the Barbary pirates. They withstood two invasions in the 15th century, one by the Sultan of Egypt in 1444 and another by the Ottoman Sultan Mehmed the Conqueror in 1480 who, after capturing Constantinople and defeating the Byzantine Empire in 1453, made the Knights a priority target.\n",
"At the Battle of Grunwald in 1410, the major victory of the united Polish–Lithuanian army against the Teutonic Order, thirty Lithuanian regiments out of the total forty were flying the \"charging knight\" banner.\n",
"On 28 June 1519 in the village of Langeloh the last knights' battle in Europe - the Battle of Soltau - took place as part of the Hildesheim Diocesan Feud. A force of Hildesheim and Lüneburg troops destroyed the Brunswick-Welf army.\n",
"Tradition has it that they faced a force numbering between 1000 and 2000 men, although it was probably several thousand, with significant numbers of knights. Sir Gilbert de Greenlaw died at Harlaw and his tombstone at Kinkell Church gives an idea of how Mar's knights were equipped. Sir Gilbert carries a hand and a half sword and wears an open-faced bascinet helmet with a mail-reinforced arming doublet beneath plate armour. Mar's men also carried spears, maces and battle axes. Tradition has it that the black armour in the entrance hall of Aberdeen's Town House belonged to Robert Davidson, Provost of Aberdeen, who fell in the battle alongside most of the burgesses with him.\n",
"In the 11th century, French knights wore knee-length mail and carried long lances and swords. The Norman knights fielded at the Battle of Hastings were more than a match for English forces, and their victory simply cemented their power and influence. Between 1202 and 1343, France reduced England's holdings on the continent to a few small provinces through a series of conflicts including the Bouvines Campaign (1202-1214), the Saintonge War (1242) and the War of Saint-Sardos (1324). Improvements in armor over the centuries led to the establishment of plate armor by the 14th century, which was further developed more rigorously in the 15th century. However, by the late 14th century and the early 15th century, French military power declined during the first part of the Hundred Years' War. New weapons, including artillery, and tactics seemingly made the knight more of a sitting target than an effective battle force, but the often-praised longbowmen had little to do with the English success. Poor coordination or rough terrain led to bungled French assaults. The slaughter of knights at the Battle of Agincourt best exemplified this carnage. The French were able to field a much larger army of men-at-arms than their English counterparts, who had many longbowmen. Despite this, the French suffered about 6,000 casualties compared to a few hundred for the English because the narrow terrain prevented the tactical envelopments envisioned in recently discovered French plans for the battle. The French suffered a similar defeat at the Battle of the Golden Spurs against Flemish militia in 1302. When knights were allowed to effectively deploy, however, they could be more useful, as at Cassel in 1328 or, even more decisively, at Bouvines in 1214 and Patay in 1429.\n"
] |
Another military or logistics question, how does an army pass a mountain, whether it's supposedly impassable or passable?
|
They (typically. Some people tried some crazy things) just went through known passes, which is why mountains are such great natural defenses. If there are only a small number of passes the defending army knows exactly where their enemy is coming through and can wait for them. Many mountain passes (esp. high mountain passes) are not very wide, either, meaning that armies could only pass through slowly and with great care. It is a pretty dangerous business.
I've been talking about the Mongols too much in this sub recently, but they were going on a raid against Russia and decided to cross the Caucasus Mountains in the middle of the winter. Unfortunately there was only one real passable spot, at Derbent. So they had to "hire" (bribe/threaten) guides, but the guides were able to run up ahead and warn everyone on the other side of the mountain that the mongols were coming for an invasion. (Genghis Khan and the Mongol War Machine By Chris Peers). Don't worry, the Mongols win and then kill everyone and terrify all of the Russian Princes for years, but the Mongols also REALLY want to find a better way to get through (they eventually just take over the city of Derbent, which makes it easier).
|
[
"For the crossing of the mountains, the Army was divided into two main columns, the first, commanded by Captain General San Martín and supported by Brigadier Major Miguel Estanislao Soler and Brigadier Bernardo O'Higgins, would take the Los Patos Pass and the second, commanded by Colonel Juan Gregorio de las Heras, would take the Uspallata Pass, which at its highest reaches some twelve thousand feet above sea level. Because this second pass was more negotiable, the artillery was taken in the second column. \n",
"\"The mountain is in front of us and it is necessary to pass over it, with enormous force and patience. It's not enough just to contemplate it nor to sneak by it via secondary paths much less go backwards claiming that the mountain is not there.\"\n",
"Contrary to the common understanding, the crossing of the Andes was not the first time that a military expedition crossed the mountain range. The difference from previous operations was the size of the army, and that it had to be ready for combat right after the crossing. The army was divided in six columns, each taking a different path. Colonel Francisco Zelada in La Rioja took the Come-Caballos pass towards Copiapó. Juan Manuel Cabot, in San Juan, moved to Coquimbo. Ramón Freire and José León Lemos led two columns in the south. The bulk of the armies left from Mendoza. San Martín, O'Higgins and Soler led a column across the Los Patos pass, and Juan Gregorio de Las Heras another one across the Uspallata Pass.\n",
"Mountain ranges are of strategic importance since they often act as a natural border, and may also be the origin of a water source (e.g. Golan Heights – \"water conflict\"). Attacking a prepared enemy position in mountain terrain requires a greater ratio of attacking soldiers to defending soldiers than a war conducted on level ground. Mountains at any time of year are dangerous – lightning, strong gusts of wind, rock falls, avalanche, snow pack, ice, extreme cold, glaciers with their crevasses and the general uneven terrain and the slow pace of troop and material movement are all additional threats to combatants. Movement, reinforcements, and medical evacuation up and down steep slopes and areas where even pack animals cannot reach involves an enormous exertion of energy.\n",
"This is a path around the main peaks, with a distance of about and height gain and loss of over . It can be walked in one day, but more commonly takes two or three. It can also be used to join different ascent and descent routes. The route does not require technical climbing.\n",
"Mountains, for example, can block off certain areas, making it unnecessary to station troops within the inaccessible area. This deployment strategy can be applied with other formidable environmental features as well, such as forests and mountains. In the former instance, dense vegetation can provide concealment for tactical movements such as setting up an ambush. In the latter, the elevation can provide an advantage to soldiers using projectile weapons, such as arrows or artillery pieces. Elevation itself is perhaps the most well-known example of terrain advantage, with gravity working to the advantage of the more elevated party.\n",
"The mountain is often climbed as a traverse from the Feliksjoch (West), to the Lisjoch (East) or vice versa. The traverse consists mostly of a narrow, snow-covered ridge, with some scrambling over rocks. In good conditions, this route is fairly easy and objectively safe, however in bad snow conditions and/or bad visibility, the ridge can be challenging because of large, sometimes double, cornices, mainly on the southern side of the ridge.\n"
] |
how does a pro gamer make a living after he / she retires?
|
It's a bit of a tough question to answer as the pro gaming industry hasn't delivered that many retirements so far.
However, if they follow a gathering based on not just their skill, but also their personality, they could complete a full career by Twitch (subscriptions, ads, donations) and YouTube (ads, sponsorships, Patreon), even if they can no longer compete at -the- top level.
Or their knowledge on games could indeed land them a job in a gaming company.
In my opinion it can be compared to "normal" sports in this regard, as sports knowledge (- > coach, manager...) or personality (media personality) can allow you to continue your career even after retirement from actual top level competition.
|
[
"In Career mode, the game puts the player in responsibility of a workshop where they must complete tasks that involve modifying pre-built computers, (e.g. removing viruses, adding new parts) or outright building a brand new computer to earn in-game cash, which can be spent on purchasing brand new parts, including computer cases, motherboards, and new processors. As the player completes tasks, the player earns a certain amount of experience points. When a certain amount of experience is reached, the player levels up, in turn unlocking newer, and often, more advanced parts. When ordering computer parts, the player is given the choice to choose between different dates of delivery, the shorter the delivery time, the more cash the player has to pay. The game offers 3 choices: same day delivery, next-day delivery, and 3 to 5 day delivery, for which the player pays an extra 100 dollars, 30 dollars or 10 dollars respectively. A calendar reminds the player of when their parts will arrive. \n",
"According to a report from FOMOS (online professional game media), he's living a life as an ordinary staff member of a company, but he said that he could return to the professional game field after the release of \"\".\n",
"A Winner Never Quits is a 1986 television film based on the true story of baseball player Pete Gray, the first one-armed man ever to play major league baseball, hired in 1943 as a \"freak attraction\" and wartime morale-booster by the Memphis Chicks, Class-A minor league ball club.\n",
"Professional gamers, or \"pro gamers\", are often associated with gaming teams and/or broader gaming associations. Teams like FaZe Clan, OpTic Gaming, Evil Geniuses, Team SoloMid, Cloud9, Fnatic, Mineski, Counter Logic Gaming, SK Telecom T1, Splyce, Team EnVyUs, and Natus Vincere consist of several professionals. In addition to prize money from tournament wins, players may also be paid a separate team salary. Team sponsorship may cover tournament travel expenses or gaming hardware. Prominent esports sponsors include companies such as Logitech and Razer. Teams feature these sponsors on their website, team jerseys and on their social media, in 2016 the biggest teams have social media followings of over a million. Associations include the Korean e-Sports Association (KeSPA), the International e-Sports Federation (IeSF), the British esports Association, and the World esports Association (WESA).\n",
"Only players who are no longer active are listed here. This list does not include active players, or free agents who have not yet retired (such players are listed below). A player is considered \"inactive\" if he has not played baseball for one year or has announced his retirement.\n",
"Perhaps because of these cultural differences, many expatriate baseball players don't last very long in NPB. Even star players often return home after five or six seasons. Of American expatriate baseball players in Japan, the longest tenures in NPB belong to Tuffy Rhodes (a total of 13 seasons in NPB), Wally Yonamine (12 seasons), Leron Lee (11 seasons), and Leon Lee and Greg Wells (10 seasons each).\n",
"An entry-level programmer can make, on average, over $66,000 annually only if they are successful in obtaining a position in a medium to large video game company. An experienced game-development employee, depending on his or her expertise and experience, averaged roughly $73,000 in 2007. Indie game developers may only earn between $10,000 and $50,000 a year depending on how financially successful their titles are.\n"
] |
how do spam telemarketers make money since almost everyone just hangs up?
|
With VOIP and cheap offshore labor, it costs virtually nothing to make those calls - partly *because* no one answers, or hangs up immediately. If you make 10,000 calls - that's every number in an exchange - and get three or four bites, you've made money.
|
[
"BULLET::::- Telemarketing fraud takes a number of forms; much like mail fraud, solicitations for the sale of goods or investments which are worthless or never delivered and requests for donations to unregistered charities are not uncommon. Callers often prey upon sick, Disability and elderly persons; scams in which a caller attempts to obtain banking or credit card information also frequently occur. One other variant involves calling a number of business offices, asking for model numbers of various pieces of office equipment in use (such as photocopiers) and sending unsolicited shipments of supplies for the machines, and then billing the victims at artificially inflated prices.\n",
"BULLET::::- Office supply scam – A very common scam where a telemarketer will target business managers responsible for purchasing office supplies, falsely representing their identity and the cost of office supplies – the most popular being toner. The caller might mislead a company’s employees into thinking that an order for office supplies has already been placed, either by an existing or former colleague, and that they are calling to chase up a signature for the order form to help them keep complete records. The company is then invoiced for unwanted, and overpriced, stationery and office supplies.\n",
"The organization has engaged telemarketers at very large costs in the past. In one instance, the ADA entered into contract with InfoCision, a telemarketing firm that works closely with nonprofits, whereby only 15% of the expected funds raised would be given to the ADA with the other 85% being kept by the telemarketing firm. Furthermore, the telemarketers were instructed to lie to prospective donors regarding how much of their donation will go to the ADA.\n",
"Telemarketing has been negatively associated with various scams and frauds, such as pyramid schemes, and with deceptively overpriced products and services. Fraudulent telemarketing companies are frequently referred to as \"telemarketing boiler rooms\" or simply \"boiler rooms\". Telemarketing is often criticized as an unethical business practice due to the perception of high-pressure sales techniques during unsolicited calls. Telemarketers marketing telephone companies may participate in telephone slamming, the practice of switching a customer's telephone service without their knowledge or authorization.\n",
"Telemarketing (sometimes known as inside sales, or telesales in the UK and Ireland) is a method of direct marketing in which a salesperson solicits prospective customers to buy products or services, either over the phone or through a subsequent face to face or Web conferencing appointment scheduled during the call. Telemarketing can also include recorded sales pitches programmed to be played over the phone via automatic dialing.\n",
"Telemarketing is marketing communication via telephone. There are two types of telemarketing: outbound and inbound. Outbound telemarketing is used by organizations to reach out to potential customers, generate sales, make appointments with salespeople and introduce new products. Inbound telemarketing is where people call the organization to complain or inquire about products. Both outbound and inbound can be used as a customer service strategy to boost sales and receive suggestions for improvement. Advantages of telemarketing include targeted communications, flexible and direct interaction between the organization and the customer, it can be an effective personal selling partner and it is cost effective compared to face-to-face contact. A disadvantage is that call centres are usually used to handle outbound and inbound telemarketing, which need to be implemented, managed and financed.\n",
"Plugola is the illicit business practice of endorsing a product or service on radio or television for personal gain, without the consent of the network or stations. “Pluggers” have been known to accept bribes of money, alcohol, or free products and services. This contrasts greatly from commercial sponsorship because the benefits of the endorsement go to the individual talent or programmers, while the stations and networks receive no revenue.\n"
] |
since inflammation in the body causes numerous fatal diseases(cancer,heart disease, etc.),why can't we just pop a few nsaids like ibuprofen every day and be on our healthy way?
|
Taking too many NSAIDs gives you stomach ulcers for starters. There's lots of side effects to antiinflammatories.
|
[
"Inflammation has many possible causes, including irritation by environmental substances, physical trauma, and infection such as bacterial, viral, or fungal. Some of these infections are sexually transmitted diseases.\n",
"Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, can cause flares of inflammatory bowel disease in approximately 25% of patients. These flares tend to occur within one week after starting regular use of the NSAID. In contrast, acetaminophen (paracetamol) and aspirin appear to be safe. Celecoxib (Celebrex), a cox-2 inhibitor, also appears to be safe, at least in short-term studies of patients in remission and on medication for their Crohn's disease.\n",
"Nonsteroidal anti-inflammatory drugs (NSAID) are effective in relieving the pain associated with venous inflammation and were found in a randomized trial to significantly decrease extension and/or recurrence of superficial vein thrombosis.\n",
"Certain drugs or exogenous chemical compounds are known to affect inflammation. Vitamin A deficiency causes an increase in inflammatory responses, and anti-inflammatory drugs work specifically by inhibiting the enzymes that produce inflammatory eicosanoids. Certain illicit drugs such as cocaine and ecstasy may exert some of their detrimental effects by activating transcription factors intimately involved with inflammation (e.g. NF-κB).\n",
"Some drugs, including rheumatoid arthritis drugs that work by blocking tumor necrosis factor-alpha (an inflammation-causingcytokine), raise the risk of activating a latent infection due to the importance of this cytokine in the immune defense against TB.\n",
"When attributed to peptic inflammation, use of nonsteroidal anti-inflammatory drugs (NSAIDs) and selective serotonin reuptake inhibitors (SSRIs) are commonly implicated. These drugs can interfere with the stomach's natural defenses against the strongly acidic environment, causing damage to the mucosa that can result in bleeding. Therefore, it is recommended that these class of drugs be taken with food or on a full stomach. Other causes of inflammation may be due to severe gastroesophageal reflux disease, \"Helicobacter pylori\" gastritis, portal hypertensive gastropathy or malignancy.\n",
"Common causes include the bacteria \"Helicobacter pylori\" and non-steroidal anti-inflammatory drugs (NSAIDs). Other less common causes include tobacco smoking, stress due to serious illness, Behcet disease, Zollinger-Ellison syndrome, Crohn disease and liver cirrhosis, among others. Older people are more sensitive to the ulcer-causing effects of NSAIDs. The diagnosis is typically suspected due to the presenting symptoms with confirmation by either endoscopy or barium swallow. \"H. pylori\" can be diagnosed by testing the blood for antibodies, a urea breath test, testing the stool for signs of the bacteria, or a biopsy of the stomach. Other conditions that produce similar symptoms include stomach cancer, coronary heart disease, and inflammation of the stomach lining or gallbladder inflammation.\n"
] |
How did the Roman people handle military defeats?
|
How would we know what an "average citizen" thought? Every text we have is produced by the elite class. Whether people lost friends or family is impossible to know in the specifics.
We do know that military disaster did not affect the political careers of the generals involved. Rosenstein in *Imperatores Victi* demonstrates very well that statistically military defeat had little or no impact on the further career of a general. Losing, as long as you got out alive, simply didn't matter.
On the personal level, among the elite, we do have evidence for friends and family grieving for loved ones. Both Catullus and Propertius write about that. Logically you would by extension think the "average citizen" would have similar feelings. There might be stele that can give more of a middle class view of the matter, but I don't know them and I don't have the resources to get them right now.
|
[
"Rome was a war-faring nation and was accustomed to setbacks. However, the recent string of defeats ending in the calamity at Arausio was alarming for all the people of Rome. The defeat left them not only with a critical shortage of manpower and lost military equipment, but also with a terrifying enemy camped on the other side of the now-undefended Alpine passes. In Rome, it was widely thought that the defeat was due to the arrogance of Caepio rather than to a deficiency in the Roman Army, and popular dissatisfaction with the ruling classes grew.\n",
"Despite their formidable reputation and host of victories Roman armies were not invincible. Romans \"produced their share of incompetents\" who led Roman armies into catastrophic defeats. Nevertheless, it was generally the fate of even the greatest of Rome's enemies, such as Pyrrhus and Hannibal, to win the battle but lose the war. The history of Rome's campaigning is, if nothing else, a history of obstinate persistence overcoming appalling losses.\n",
"In their battles against a wide variety of opponents, Rome's ruthless persistence, greater resources and stronger organization wore down their opponents over time. Rome's massive manpower supply was the foundation of this approach. Opponents could be relentlessly weakened and exhausted over the long run. In Spain, resources were thrown at the problem until it yielded over 150 years later—a slow, harsh grind of endless marching, constant sieges and fighting, broken treaties, burning villages and enslaved captives. As long as the Roman Senate and its successors were willing to replace and expend more men and material decade after decade, victory could be bought through a strategy of exhaustion.\n",
"A prime example of Roman loss in battle was the Battle of Teutoburg Forest in AD 9, where three entire legions led by Publius Quinctilius Varus were destroyed by Arminius, leader of the Cherusci, an apparent Roman ally. Augustus retaliated by dispatching Tiberius and Drusus to the Rhineland to pacify it, which had some success although the battle of AD 9 brought the end to Roman expansion into Germany. Roman general Germanicus took advantage of a Cherusci civil war between Arminius and Segestes; they defeated Arminius, who fled that Battle of Idistaviso in AD 16 but was killed later in 21 due to treachery.\n",
"In \"The Complete Roman Army\" (2003) Adrian Goldsworthy, a British military historian, sees the causes of the collapse of the Roman Empire not in any 'decadence' in the make-up of the Roman legions, but in a combination of endless civil wars between factions of the Roman Army fighting for control of the Empire. This inevitably weakened the army and the society upon which it depended, making it less able to defend itself against the growing numbers of Rome's enemies. The army still remained a superior fighting instrument to its opponents, both civilized and barbarian; this is shown in the victories over Germanic tribes at the Battle of Strasbourg (357) and in its ability to hold the line against the Sassanid Persians throughout the 4th century. But, says Goldsworthy, \"Weakening central authority, social and economic problems and, most of all, the continuing grind of civil wars eroded the political capacity to maintain the army at this level.\" Goldsworthy set out in greater detail his theory that recurring civil wars during the late fourth and early fifth centuries contributed to the fall of the West Roman Empire (395-476), in his book \"The Fall of the West: The Slow Death of the Roman Superpower\" (2009).\n",
"Rome's military secured Rome's territory and borders, and helped to impose tribute on conquered peoples. Rome's armies had a formidable reputation; but Rome also \"produced [its] share of incompetents\" and catastrophic defeats. Nevertheless, it was generally the fate of Rome's greatest enemies, such as Pyrrhus and Hannibal, to win early battles but lose the war.\n",
"Singular conclusions on ancient warfare challenged historiography in so far as he tried to show that the figures for armies in antiquity were inflated in the original sources, and that, contrary to what is stated in most writings, the winner in a battle usually had more troops than the loser. Consequently, he gave completely different interpretations to some of the most famous battles in history, like Marathon, Gaugamela, and Zama by concluding that Rome's vaunted advantage over \"barbarians\" rested, not so much in their discipline and refined tactics, but rather in their superior logistical support. The Romans were able to raise and maintain huge armies on the field, while the \"barbarians\" were unable to match their numbers.\n"
] |
the difference between iphone and android, and the pro's and con's of each.
|
Things Android phones can do *without* being rooted (the same level of permission you currently have on the iPhone):
* Change the keyboard input. [8pen](_URL_1_), [SwiftKey](_URL_0_), and [Swype](_URL_9_) are some good examples.
* Use any appstore or download apps directly from web pages. The [Amazon AppStore](_URL_10_) even has one free (as in, a 100% discounted) app every day.
* Put widgets on your home screen, like the HTC clock/weather widgets, calendar widgets, [gReader](_URL_2_) widgets, and battery management/service widgets for turning on/off features like 4G, WiFi, GPS and Bluetooth.
* Explore your filesystem with apps like [ASTRO File Manager](_URL_3_).
* *Admittedly there are fewer games out for Android than iPhone* (in surveys a while back, a statistically significant percentage of people said they got an iPhone primarily for the games) but there is a great family of video game console emulators like [SNESoid](_URL_4_) for the Super NES, NESoid for the NES, and GENSoid for the Sega Genesis among others.
Things you can do *with* a rooted phone:
* Install a custom ROM (an operating system like OSX or Windows 7) like [CM7](_URL_5_).
* Underclock/overclock the processor to improve battery live or improve performance.
* Use your phone as a wireless hotspot without paying the extra $25/month for the service.
* Create comprehensive recovery files (backups) with [Clockwork Mod](_URL_6_). Additionally backup, freeze and delete apps on your phone through [Titanium Backup](_URL_7_).
No iPhone supports 4G, at least one Android phone now supports Netflix, and Android is [open source](_URL_8_).
But Steve Jobs and Apple will always be the king of "it just works." So if you want to sacrifice all/most of those features to never have to learn a phone that you'll probably be owning for the next 1 or 2 years, Apple might be the phone for you. I just wanted to enumerate all of the reasons why Android phones are for me.
If it's any credit to Apple, their products have definitely been successful at bringing space-age technology to the baby boomers.
|
[
"The iPhone runs an operating system known as iOS (formerly iPhone OS). It is a variant of the Darwin operating system core found in macOS. Also included is the \"Core Animation\" software component from Mac OS X v10.5 Leopard. Together with the graphics hardware (and on the iPhone 3GS, OpenGL ES 2.0), it is responsible for the interface's motion graphics. The iPhone comes with a set of bundled applications developed by Apple, and supports downloading third-party applications through the App Store.\n",
"iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that presently powers many of the company's mobile devices, including the iPhone, iPad, and iPod Touch. It is the second most popular mobile operating system globally after Android.\n",
"To further differentiate features between iPhones and iPads, iOS 13 is now specific to the iPhone and iPod touch, and Apple has rebranded the tablet oriented platform with its own operating system, iPadOS.\n",
"iOS (formerly named iPhone OS) was created by Apple Inc. It has the second largest installed base worldwide on smartphones, but the largest profits, due to aggressive price competition between Android-based manufacturers. It is closed source and proprietary, and is built on the open source Darwin operating system. The iPhone, iPod Touch, iPad and second or third-generation Apple TV all use iOS, which is derived from macOS.\n",
"Google countered to this investigation that their practices with Android were no different with how Apple, Inc. or Microsoft bundles their own proprietary apps on their respective iOS and Windows Phone, and that OEMs were still able to distribute Android-based phones without the Google suite of apps.\n",
"Like the iPhone, with which it shares a development environment the iPad only runs its own software, software downloaded from Apple's App Store, and software written by developers who have paid for a developer's license on registered devices. The iPad runs almost all third-party iPhone applications, displaying them at iPhone size or enlarging them to fill the iPad's screen. Developers may also create or modify apps to take advantage of the iPad's features, and there are onemillion apps optimized for the iPad, . Application developers use iOS SDK for developing applications for iPad. The iPad originally shipped with a customized iPad-only version of iPhone OS, dubbed v3.2. On September 1, it was announced the iPad would get iOS 4.2 by November 2010; to fulfill this Apple released iOS 4.2.1 to the public on November 22.\n",
"The iPad runs on iOS, which was created for the iPhone and iPod Touch. The first iPad was released in 2011. Although built on the same underlying Unix implementation as MacOS, its user interface is radically different. iOS is designed for fingers and has none of the features that required a stylus on earlier tablets. Apple introduced multi-touch gestures, such as moving two fingers apart or together to zoom in or out, also termed \"pinch to zoom\". iOS is built for the ARM architecture.\n"
] |
Considering all types of movement we're subjected to, how fast are we actually traversing through space at any given point in time?
|
what is the reference point?
this question is asked all the time and it's always the same..
1. Do a search this has been asked before
2. What exactly are we calling our fixed reference point? (the entire universe is in flux)
|
[
"With current technology severely limiting the velocity of space travel, however, the differences experienced in practice are minuscule: after 6 months on the International Space Station (ISS) (which orbits Earth at a speed of about 7,700 m/s) an astronaut would have aged about 0.005 seconds less than those on Earth. The cosmonauts Sergei Krikalev and Sergei Avdeyev both experienced time dilation of about 20 milliseconds compared to time that passed on Earth.\n",
"Heytesbury and others mathematically determined the distance covered by a body undergoing uniformly accelerated motion (today solved by integration), stating that \"a moving body uniformly acquiring or losing that increment [of speed] will traverse in some given time a [distance] completely equal to that which it would traverse if it were moving continuously through the same time with the mean degree [of speed]\".\n",
"Since the action is proportional to the length of the particle's worldline (in other words its trajectory in spacetime), this route illustrates that finding the stationary action is akin to finding the trajectory of shortest or largest length in spacetime. Correspondingly, the equations of motion of the particle are akin to the equations describing the trajectories of shortest or largest length in spacetime, \"geodesics\".\n",
"The rate of change of velocity is called acceleration, and the rate of change of momentum is called force. To reach a given velocity, one can apply a small acceleration over a long period of time, or one can apply a large acceleration over a short time. Similarly, one can achieve a given impulse with a large force over a short time or a small force over a long time. This means that for manoeuvring in space, a propulsion method that produces tiny accelerations but runs for a long time can produce the same impulse as a propulsion method that produces large accelerations for a short time. When launching from a planet, tiny accelerations cannot overcome the planet's gravitational pull and so cannot be used.\n",
"Gravity has a large influence on walking speed, muscle activity patterns, gait transitions and the mechanics of locomotion, which means that the kinematics of locomotion in space need to be studied in order to optimize movements in that environment.\n",
"We can assume that I'm moving, not in space, but only just in time. Transitional corridor so narrow! Do not overtake, not to lag behind, just went through stops moving. When I stop moving, stepping over me ... Holt is not – there are only fellow travelers!\n",
"If one's goal is simply to \"reach space\", for example in competing for the Ansari X Prize, horizontal motion is not needed. In this case the lowest required delta-v, to reach 100 km altitude, is about 1.4 km/s. Moving slower, with less free-fall, would require more delta-v.\n"
] |
why does spain have strong, independent cultures (i.e. basque, catalonia) while other european nations seem to be more culturally and linguistically uniform?
|
While I don't disagree with your question, let me find you some examples which invalidate it:
- Belgium is part French part Dutch, different languages, different traditions, different cultures.
- Yugoslavia, but that was only a stable country under Tito.
- Turkey and its Kurdistan part.
- UK (or was it GB?) and Scotland and Northern-Ireland.
- The former east and west parts of Germany, still cultural very different.
- Czech and Slovakia were split up in the late 1990s IIRC.
- Italy and Sicily.
|
[
"However, some traits of the Spanish spoken in Spain are exclusive to that country, and for this reason, courses of Spanish as a second language often neglect them, preferring Mexican Spanish in the United States and Canada whilst European Spanish is taught in Europe. Spanish grammar and to a lesser extent pronunciation can vary sometimes between variants.\n",
"Spain is a Western country. Almost every aspect of Spanish life is permeated by its Roman heritage, making Spain one of the major Latin countries of Europe. Spanish culture is marked by strong historic ties to Catholicism, which played a pivotal role in the country's formation and subsequent identity. Spanish art, architecture, cuisine, and music have been shaped by successive waves of foreign invaders, as well as by the country's Mediterranean climate and geography. The centuries-long colonial era globalised Spanish language and culture, with Spain also absorbing the cultural and commercial products of its diverse empire.\n",
"However, unlike in other European countries such as France, where regional languages were spoken in rural areas or less developed regions, two important regional languages of Spain were spoken in some of the most industrialized areas, which, moreover, enjoyed higher levels of prosperity, in addition to having their own cultures and historical consciousness. These were the Basque Country and Catalonia. This gave rise to peripheral nationalisms along with Spanish nationalism.\n",
"Spain's multi-cultural richness beginning in the era of Umayyad dynasty rule in that land (711-1031) was one of the main reasons why European scholars were traveling to study there as early as the end of the 10th century. As the Arabic-speaking rulers who initially came in 711 intermingled and intermarried with local populations, the co-existence of Arabic, Hebrew, Latin, and the local Romance vernacular had seen the emergence of new pidgin vernaculars and bilingual song forms, as well as the creation of new bodies of literature in Arabic and Hebrew. The environment bred multi-lingualism. This era saw the development of a large community of Arabic-speaking Christians (known as Mozarabs) who were available to work on translations. But translating efforts were not methodically organized until Toledo was reconquered by Christian forces in 1085. The new rulers inherited vast libraries containing some of the leading scientific and philosophical thought not only of the ancient world, but of the Islamic east, the cutting edge of scientific discourse of the era—and it was all largely in Arabic.\n",
"The existence of multiple distinct cultures in Spain allows an analogy to be drawn to the United Kingdom. Using the term Spanish for someone of Spanish descent would then be expected to be equivalent to using Briton to describe someone descending from some part of the United Kingdom. Cultures within the United Kingdom, such as English, Irish, Scottish, and Welsh, would then correspond in this analogy to cultures within Spain such as Castilian, Catalan, Galician and Basque among others. In contrast with Spain, because of centuries of gradual and mutual consolidation across the Iberian Peninsula, such distinctions tend to be blurred. It is a subtle, yet important, distinction.\n",
"According to some, derived from the fact that almost all Spaniards are Catholic, and Spain remains to this day one of the most homogeneous Western countries, Spanish Judeophobia reflects a national obsession with religious and ethnic unity which is based on the conception of an imaginary \"internal enemy\" plotting the downfall of the Catholic religion and the traditional social order. However, this assumption clashes with the fact that 21st-century Spain is one of the most secularized countries in Europe, with only 3% of Spaniards considering religion as one of their three most important values and thus not linking it to their national or personal identity. Furthermore, in modern Spain there is not an \"internal enemy\" scare but in far-right circles, which are more often focused against Muslim immigration as well as Catalan and Basque separatism, way more visible phenomena. Modern antisemitic-like attitudes in Spain are actually related to the perceived abusive policies of the State of Israel against Palestinians and in the international scene rather than to any kind of religious or identity obsession, and it has been defined by Jewish authors as an \"antisemitism without antisemites.\"\n",
"Folk and popular dance and music also varies greatly among Hispanics. For instance, the music from Spain is a lot different from the Hispanic American, although there is a high grade of exchange between both continents. In addition, due to the high national development of the diverse nationalities and regions of Spain, there is a lot of music in the different languages of the Peninsula (Catalan, Galician and Basque, mainly). See, for instance, Music of Catalonia or Rock català, Music of Galicia, Cantabria and Asturias, and Basque music. Flamenco is also a very popular music style in Spain, especially in Andalusia. Spanish ballads \"romances\" can be traced in Argentina as \"milongas\", same structure but different scenarios.\n"
] |
why do guys insist on sending unsolicited dick pictures. does that ever really work?
|
Men are very visual creatures, and quick to arouse. A man can go from no arousal to immediately turned on just with a quick flash of a girl's boobs. As a result of this nature, many men don't grasp that women don't work the same way, and aren't interested much in seeing a dick unless already aroused.
Combine that with the general negative effect that arousal tends to have on your ability to make good decisions, and you have horny men sending what they think are arousing pictures to someone who is in no mood for them.
|
[
"\"Snuff\" follows three men who are waiting to immortalize themselves into pornography history as they wait to bed Cassie Wright, a former porn queen who has fallen into harder times. Each chapter follows a different guy (Mr. 600, Mr. 72, and Mr. 137), as well as Sheila, the female wrangler who dictates who is the next to be filmed with Cassie Wright. As the three men wait, each starts to divulge their true reasons for wanting to be filmed, as well as discuss the sordid history of Cassie Wright and her reason for suddenly dropping out of the pornography industry for a year. As backgrounds, secrets, and would-be children start to appear, the tensions in the room start to rise and in the end the true secrets of her comeback, and who really is Cassie Wright's porn child, are the last things any of them suspect.\n",
"Also, Chase faces some personal troubles after a full-frontal nude photo of him, photoshopped to make his penis look much shorter than it is, is posted on his own social networking website. His password (which was unsafely set to 'password') is changed as well, so he is unable to modify the contents himself. He suspects one of the girls he had sex with after a wedding (episode 8, \"Small Sacrifices\") has taken the photo out of revenge for his lack of interest the morning after. He tracks down all the girls but each of them professes their innocence. In the end, he remembers that the sister of one of the girls he slept with was in the same room that night. When he goes and looks for her it appears he already chatted with her one time. She tells him that he seemed like a nice guy but when she told him she didn't do sex after one date, he ran. After that she felt he needed a lesson. She eventually gives him the new password, so Chase can finally repair his own profile. Chase then apologizes and asks her on a real date without sex, to which she happily declines.\n",
"It transfers to Pete, at a photo shoot. The photographer takes a cell phone from his coworker and takes pictures with it, and prompts Pete to show his penis, making it look like Pete took them (in reference to real cell phone photos leaked from Pete's cell phone after he took them to send to his girlfriend). Several teenage girls are outraged after they see the pictures and realize Pete has a small penis.\n",
"The lack of attribution for Unsplash photos has been the subject of controversy among photography circles, due to some companies using free Unsplash photography for profit without compensating the photographers. Unsplash itself has stated that it does not support the practice.\n",
"\"Dick in a Box\" is the debut single by American comedy troupe The Lonely Island, featuring singer Justin Timberlake. The song and music video debuted on \"Saturday Night Live\" as an \"SNL\" Digital Short on December 16, 2006. The video depicts two early-1990s R&B ballad singers Andy (Andy Samberg) and Raif (Timberlake) crooning a holiday song about making a gift for their girlfriends of their penises wrapped in boxes (strategically placed) topped with bows.\n",
"During the first week of April 2009, the United States Postal Service announced that they were unwilling to deliver promotional postcards made for \"Look\". The postcard advertisements depict a man with his boxers around his ankles in the midst of sexual intercourse with a woman in a generic mail room setting, as captured on a hidden camera. The nudity in the image is not blatant but the postal service has characterized the content as obscene. The postcard image is headlined by the caption: \"It is LEGAL for your company to get permission to install HIDDEN CAMERAS IN THE WORKPLACE!\"\n",
"Peter confronts Kris with this revelation, but she yet again denies everything and states that the photo is a means for single office women like her to discourage male co-workers from hitting on them. (Note: throughout the entire film, whenever Kris is caught in a lie about her past or work, she makes up a whole new lie on the spur of the moment to replace or patch up the old lie). Peter, however, refuses to believe her anymore. He is now aware that Kris is a master manipulator and sociopath, but also aware that he will never be able to prove that Kris was responsible for all the deaths and incidents at the company nor will she ever admit to any wrongdoing. Peter decides to remove Kris the old fashioned way: he fires Kris and orders her detained until the police can escort her out.\n"
] |
how did early man manage to drink the recommended 2 litres of water a day without access to clean water and remain strong enough to maintain his active lifestyle?
|
The recommended two litres of water a day is junk science invented by drinks manufacturers to sell more products. Actual scientists say you should drink when thirsty, and not drink when not thirsty (unless you are sick or actually dehydrated).
Clean water was difficult to find, and at first humans settled wherever they could find fresh water. Later, they learned how to dig wells, giving them access to more fresh water.
Of course, by our standards, the water wasn't exactly clean. But people had immune systems to cope: being exposed to all the common pathogens very early in life helped give people the immunity they needed.
It was still possible to pick up parasites through the water, though, so it wasn't totally safe, and infant mortality in particular was very high. But the human race compensated for that by not having birth control in those days: those that did survive childhood could usually go on to live long and relatively healthy lives (the average life expectancy of around 40 is so low because of the high infant mortality, and because of constant wars and battles).
This is where beer comes in. Beer is mentioned in Ancient Egypt, although it was quite different from modern beer. Essentially, it was liquid bread, with a much lower alcohol content than we're used to now, so it could be given to children. In mediaeval Europe it was an important supplement to a peasant's diet (the belief that beer is considered a "foodstuff" in Bavaria is a complete urban myth, but not an implausible one). The process of brewing the beer killed off most of the germs and parasites, and the alcohol killed off the rest.
Basically, a combination of humans not actually needing as much water as the Coca-Cola Corp wants you to believe, a more robust immune system, and the discovery of the brewing process.
|
[
"A typical person will lose minimally two to maximally four liters of water per day under ordinary conditions, and more in hot, dry, or cold weather. Four to six liters of water or other liquids are generally required each day in the wilderness to avoid dehydration and to keep the body functioning properly. The U.S. Army survival manual does not recommend drinking water only when thirsty, as this leads to underhydrating. Instead, water should be drunk at regular intervals. Other groups recommend rationing water through \"water discipline\".\n",
"According to the WHO, each human being requires a bare minimum of 20 litres of fresh water per day for basic hygiene; this equals 7.3 cubic metres (about 255 ft) per person, per year. Based on the availability, access and development of water supplies, the specific usage figures vary widely from country to country, with developed nations having existing systems to treat water for human consumption, and deliver it to every home. At the same time however, some nations across Latin America, parts of Asia, South East Asia, Africa and the Middle East either do not have sufficient water resources or have not developed these or the infrastructure to the levels required. This occurs for many varied reasons. It has resulted in conflict and often results in a reduced level or quantity of fresh water per capita consumption; this situation leads toward disease, and at times, to starvation and death.\n",
"Living away from drinking water supplies often requires some form of portable water treatment process. These can vary in complexity from the simple addition of a disinfectant tablet in a hiker's water bottle through to complex multi-stage processes carried by boat or plane to disaster areas.\n",
"A human being can survive an average of three to five days without the intake of water. The issues presented by the need for water dictate that unnecessary water loss by perspiration be avoided in survival situations. The need for water increases with exercise.Since the human body is composed of up to 78% water, it should be no surprise that water is higher on the list than fire or food. Ideally, a person should drink about a gallon of water per day. Many lost persons perish due to dehydration, and/or the debilitating effects of water-born pathogens from untreated water.\n",
"Provision of adequate food and water was a major logistical problem. Water was brought in each day by trucks from supply areas one to two hours away. Water was rationed to 10–15 liters per person per day in the camp and 50–60 liters per hospitalized patient/day).\n",
"As Garrison-Quartermaster Lt. William Hume put it, \"the inhabitants owe nothing to the British Government for the small supply of water they have had for 150 years ... it would appear that from our conquest in 1704 down to within the last 15 years, nothing was done to collect water or to increase the supply, nothing whatsoever.\" The Commission concluded that the existing water supply was \"bad, deficient, and costly\", that drainage was \"defective\" to \"very bad\" and that sanitation was \"most offensive and dangerous to health\" for the 16,000 inhabitants and 6,000–7,000 members of the garrison. The water allowances per head were so low that it was \"just as if the garrison were in a state of siege\" and were \"utterly incommensurate to the soldiers' wants in such a climate.\" A chemical analysis of the water supply showed that it had an \"extraordinary\" amount of impurities, including excessive amounts of organic matter, nitrates and chlorides. This indicated that sea water and sewage had infiltrated the town's supply of drinking water. The findings led to the old Spanish aqueduct and wells being closed down permanently as it was realised that they posed a severe hazard to public health.\n",
"Until the 1950s, water was carried by hand from the local wells. Buckets of water were carried a few miles by the local children for washing and drinking purposes. The most famous of these wells was known as \"Crennans well\" which produced a very high quality of drinking water. The miners small three roomed cottages which could be homes to ten plus people were thatched with rushes or reeds from the local area, sanitation did not exist, transport to Mass shopping and visiting was either by foot or by horse/donkey or \"jennit\" and cart.\n"
] |
Does smoke have weight?
|
Smoke has weight, yes, but that experiment is no way to find it. For example, try it with a piece of magnesium instead of a cigarette. If you burn magnesium, it gives off some smoke, and at the end the ashes are actually **heavier** than the original piece of magnesium. How? Burning is just rapid oxidation, and what's left is magnesium oxide, which contains oxygen from the air, which has mass. Burning takes mass out of the air and adds it to the ashes and the smoke, and the proposed experiment doesn't take that into account.
Much of a cigarette burning is carbon, so when that oxidises it becomes carbon dioxide (or monoxide), both of which are gasses which dissipate away. Do they count as part of the smoke? Probably not, but they do in that experiment.
I don't know how to formulate an experiment to weigh smoke, but the experiment given in the film is flawed.
Edit: Also, because this way of thinking about fire seems so intuitively reasonable, it was pretty much our best scientific model of it for a long time. They called it [phlogiston theory](_URL_0_).
|
[
"Cigarette smoking for weight loss is a weight control method whereby one consumes tobacco, often in the form of cigarettes, to decrease one's appetite. The practice dates to early knowledge of nicotine as an appetite suppressant.\n",
"There is much controversy concerning whether smokers are actually thinner than nonsmokers. Some studies have shown that smokers—including long term and current smokers—weigh less than nonsmokers, and gain less weight over time. Conversely, certain longitudinal studies have not shown correlation between weight loss and smoking at least among young persons. Accordingly, while the connection between nicotine and appetite suppression, as well as other physiological responses to nicotine consumption, has been established, whether these chemical and biological reactions translate to smokers being thinner than nonsmokers (at least concerning certain age groups), is still debated. Age may act as a compounding factor in some of these studies. Essentially, a causal relationship has not been explicitly established between physiological effects of nicotine and epidemiological findings about weight among smokers and nonsmokers.\n",
"While most adults do not smoke for weight control, studies have shown that associations between tobacco use, being thin and desire for weight control do influence adolescents in terms of smoking behavior. Research demonstrates that adolescent girls that strongly value being thin are more likely to initiate smoking. Additionally, girls already engaged in risky behavior for weight control are at increased odds to begin smoking as well.\n",
"In short, smoking is harmful in that it contributes to low birth weight which has higher mortality than normal birth weight, but other causes of low birth weight are generally \"more\" harmful than smoking.\n",
"Smoking has a significant effect on an individual's weight. Those who quit smoking gain an average of 4.4 kilograms (9.7 lb) for men and 5.0 kilograms (11.0 lb) for women over ten years. However, changing rates of smoking have had little effect on the overall rates of obesity.\n",
"Tobacco smoke may be grouped into a particulate phase (trapped on a glass-fiber pad, and termed \"TPM\" (total particulate matter)) and a gas/vapor phase (which passes through such a glass-fiber pad). \"Tar\" is mathematically determined by subtracting the weight of the nicotine and water from the TPM. However, several components of tobacco smoke (e.g., hydrogen cyanide, formaldehyde, phenanthrene, and pyrene) do not fit neatly into this rather arbitrary classification, because they are distributed among the solid, liquid and gaseous phases.\n",
"Several studies have been conducted over the past decade examining this issue in depth. While it has generally been found that white females are more apt to smoke to lose weight, one study found that smoking to lose or control weight is not limited to white females, but is prevalent across racial and gender boundaries. Within all racial groups, it was found that weight concerns and negative body perceptions were a significant factor in an adolescent's decision to smoke. The relationship between weight and smoking amongst young men was only statistically significant in white or mixed race groups.\n"
] |
how do you perform cpr and give compressions to a person who has fractured his chest bones?
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In a situation when a person actually needs CPR a beating heart takes precedence over anything else even a fractured sternum/ribs. if the ribs puncture your lung and give you a pneumothorax, they can still fix you up later, but if the heart stop beating only for 5 minutes your brain cells will start to become necrotic right away (with the hippocampus being the most vulnerable).
Source: took a CPR class in med school, asked the same question that was my instructor answer.
|
[
"BULLET::::- Cardiopulmonary Resuscitation (CPR) A series of chest compressions and ventilations that try to circulate blood containing oxygen throughout the body to vital organs in an attempt to resuscitate a victim. A lifeguard performing CPR on an adult should use two hands on the chest, with the ring finger of the bottom hand lined up with the nipple. The chest compressions should consist of thirty compressions to 2 rescue breaths with a depth of at least 2 inches but no more than 2.4 inches. For a child the hands should be placed the same way as an adult, however, chest compressions should be about two inches. The rate at which the compressions should be is 100–120 compressions per minute for both child and adult. For an infant, the hand placement should be two fingers at the center of the chest, again just below the nipple line. The depth of compressions should be about one and a half inches with compressions being 30:2. The rate of compressions should be 100–120 compressions per minute. The chest compressions to ventilation's ratio changes from 30:2 to 15:2 for a child and infant during two rescuer CPR.\n",
"CPR involves chest compressions for adults between and deep and at a rate of at least 100 to 120 per minute. The rescuer may also provide artificial ventilation by either exhaling air into the subject's mouth or nose (mouth-to-mouth resuscitation) or using a device that pushes air into the subject's lungs (mechanical ventilation). Current recommendations place emphasis on early and high-quality chest compressions over artificial ventilation; a simplified CPR method involving chest compressions only is recommended for untrained rescuers. In children, however, only doing compressions may result in worse outcomes, because in children the problem normally arises from a respiratory, rather than cardiac problem. Chest compression to breathing ratios is set at 30 to 2 in adults.\n",
"Bystanders without medical training who see an individual suddenly collapse should call for help and begin chest compressions immediately. The American Heart Association currently supports \"Hands-only\"™ CPR, which advocates chest compressions without rescue breaths for teens or adults. This is to minimize the reluctance to start CPR due to concern for having to provide mouth-to-mouth resuscitation.\n",
"Cardiopulmonary resuscitation is a particularly well-known heroic measure; vigorous chest compressions often result in fracturing one or more of the patient's ribs, but since the alternative is certain death, the technique is accepted as necessary.\n",
"A resuscitative thoracotomy (sometimes referred to as an emergency department thoracotomy (EDT), trauma thoracotomy or, colloquially, as \"cracking the chest\") is a thoracotomy performed to resuscitate a major trauma patient who has sustained severe thoracic or abdominal trauma and who has entered cardiac arrest because of this. The procedure allows immediate direct access to the thoracic cavity, permitting rescuers to control hemorrhage, relieve cardiac tamponade, repair or control major injuries to the heart, lungs or thoracic vasculature, and perform direct cardiac massage or defibrillation. For most persons with thoracic trauma the procedure is not necessary; only 15% of those with thoracic injury require the procedure.\n",
"Cardiopulmonary resuscitation (CPR) is an emergency procedure that combines chest compressions often with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is in cardiac arrest. It is recommended in those who are unresponsive with no breathing or abnormal breathing, for example, agonal respirations.\n",
"For adults with cardiac arrest, compression-only (hands-only or cardiocerebral resuscitation) CPR which involves chest compressions without artificial ventilation is recommended as the method of choice for the untrained rescuer or those who are not proficient as it is easier to perform and instructions are easier to give over a phone. In adults with out-of-hospital cardiac arrest, compression-only CPR by the lay public has an equal or higher success rate than standard CPR. It is hoped that the use of compression-only delivery will increase the chances of the lay public delivering CPR.\n"
] |
Why did the Japanese attack the United States to bring the US into WW2? Were they completely the aggressors or had some US policy given them reasons to attack?
|
For about 40 years the US and Japan had been on a collision course. A whole host of factors made it so that the nations and populations felt each other was a natural foe, and that when war came it would be particularly brutal.
To go through a few:
1. Residual Colonialism clashing with Japan's desire to make good its industrialization and ascendancy. The US and UK were still committed to the "Open Door Policy" and Western domination of Chinese and nearby markets, while Japan sought a greater sphere of influence itself after smashing Russian power in 1905, and proving itself able to be a colonial power in its own right.
2. Race based policy and rhetoric on both sides. California for instance had some particularly heavy handed anti Asian policies,a nd immigration was severely limited. And deeply held beliefs that immigrants owed allegiance to the Emperor over Washington. Meanwhile 3 generations of Japanese were fed the nationalist narrative of the Yamato Race, one people focused on greatness brought together under the Divine Emperor, and who would replace the Colonial powers as the new dominant power of the Asian peoples.
3. The feelings of dishonor and anger over the Naval Treaties. In the 20's and 30's at the Washington and London Conferences Japan was pressured into accepting a 5:5:3 ratio in Battleships and in general naval tonnage compared to the US and UK. That was seen not as a recognition of global vs regional interests, but as a move to hinder the growth of the rising sun of Japan. There was then national rage and mourning when multiple unfinished battleships were taken from the dockyards and scuttled.
4. Progressive tightening of economic screws by FDR. When Japanese officers in Manchuria repeatedly either acted without prior approval or created crisis, Japan found itself in its long awaited move to conquer China. In response FDR went through a series of restriction to prevent the US from feeding the war machine for a conflict he was against. Items such as scrap metal were not allowed to be sold to Japanese customers. Finally Oil was embargoed, and this then would have either forced an end to the war, or the IJA and IJN would have ground to a halt.
5. Prevailing thought on how to fix that weakness was to snatch up the Dutch East Indies, and Malaysia from the Netherlands and the UK. However the US controlled Philippines stood in the way, and even without a direct attack the fear was that the US would come to its allies aid, and either way a general war would commence.
So the key becomes, with a smaller navy, how do you secure the resources needed to wage war, while also fighting off an enemy fleet equal your own?
From that problem was born the plan to attack pearl Harbor and try to remove one of those considerations for a time. Thus the war would go A. Knock the USN off balance and freeze them B. Seize the resources you need to keep going in the South pacific. C. Prepare a string of Islands through the Pacific to use as bastions to bleed the USN when it did come to fight, then a giant climactic battle could be joined to sink the rest of them. D. Then hopefully the US would be tired of war and open negotiations which would leave Japan with the territory it needed to be resource independent.
Excellent Sources: War Plan Ornage by Edward S. Miller
Pacific Crucible by Ian W. Toll
and Shattered Sword by Parshall and Tully
|
[
"In late 1941, Japan's government, led by Prime Minister and General Hideki Tojo, decided to break the US-led embargo through force of arms. On December 7, 1941, the Imperial Japanese Navy launched a surprise attack on the American fleet at Pearl Harbor, Hawaii. This brought the US into World War II on the side of the Allies. Japan then successfully invaded the Asian colonies of the United States, the United Kingdom, and the Netherlands, including the Philippines, Malaya, Hong Kong, Singapore, Burma, and the Dutch East Indies.\n",
"The decision by Japan to attack the United States remains controversial. Study groups in Japan had predicted ultimate disaster in a war between Japan and the U.S., and the Japanese economy was already straining to keep up with the demands of the war with China. However, the U.S. had placed an oil embargo on Japan and Japan felt that the United States' demands of unconditional withdrawal from China and non-aggression pacts with other Pacific powers were unacceptable. Facing an oil embargo by the United States as well as dwindling domestic reserves, the Japanese government decided to execute a plan developed by the military branch largely led by Osami Nagano and Isoroku Yamamoto to bomb the United States naval base in Hawaii, thereby bringing the United States to World War II on the side of the Allies. On September 4, 1941, the Japanese Cabinet met to consider the war plans prepared by Imperial General Headquarters, and decided:\n",
"The United States and Britain had imposed an oil embargo on Japan, threatening to stop the Japanese war effort, but the European colonial powers were weakening and suffering early defeats in the war with Germany; only the US Pacific Fleet stood in the way of seizing the oil-rich Dutch East Indies. Because of this, Japan's focus was ultimately directed to the south, leading to its decision to launch the attack on Pearl Harbor on 7 December of that year. Despite plans being carried out for a potential war against the USSR (particularly contingent on German advances towards Moscow), the Japanese would never launch an offensive against the Soviet Union. In 1941, the two countries signed agreements respecting the borders of Mongolia and Manchukuo and pledging neutrality towards each other. In the closing months of World War II, the Soviet Union would annul the Neutrality Pact and invade the Japanese territories in Manchuria, northern Korea, and the southern part of Sakhalin island.\n",
"On 7 December 1941, the Empire of Japan entered the war by attacking the British colony of Malaya and the American naval base at Pearl Harbor. Four days later, Germany declared war on the United States, bringing the Americans into the European conflict. The United States military favoured Operation Sledgehammer, a cross-channel invasion of German-occupied France. Such a move was opposed by the British, who acknowledged the military weakness of the Allies to undertake such an endeavour, especially as the British Army would have to provide the main force for such an operation. In July 1942, the Anglo-Americans met in London and agreed that Operation Roundup, Sledgehammer's successor, would be postponed and joint operations would begin in North Africa.\n",
"On 1 August 1941, the United States, angered by Japanese atrocities in the second Sino-Japanese War, imposed an oil embargo on Japan. This led to the Attack on Pearl Harbor, getting the United States to join the Allies in World War 2. The U.S. government provided military, logistical and other aid to the Chinese Nationalist Party (KMT) army led by Chiang Kai-shek in its campaign against the Japanese, until the Japanese surrender to the United States in August 1945. This surrender brought to an end the Japanese Puppet state of Manchukuo and the Japanese-dominated Wang Jingwei regime.\n",
"An attack by Japan on the U.S. could not guarantee the U.S. would declare war on Germany. After such an attack, American public anger would be directed at Japan, not Germany, just as happened. The Tripartite Pact (Germany, Italy, Japan) called for each to aid another in defense; Japan could not reasonably claim America had attacked Japan if she struck first. For instance, Germany had been at war with the UK since 1939, and with the USSR since June 1941, without Japanese assistance. There had been a serious, if low-level, naval war going on in the Atlantic between Germany and the U.S. since summer of 1941, as well. Nevertheless, it was only Hitler's declaration of war on 11 December, unforced by treaty, that brought the U.S. into the European war.\n",
"In 1940 U.S. President Roosevelt sanctioned Japan to punish it for invading China and southern Indochina under the Export Control Act. He later imposed sanctions under the Trading With the Enemy Act in 1941. Some claim that this was the reason for the attack on Pearl Harbor later in 1941. Sanctions were lifted in 1946. Japan was deeply unpopular for the surprise attack on Pearl Harbor. Because Japan was the reason for the United States to have to enter WW2, and due to the fact many Americans wanted to stay out of European wars during both wartime periods, Japanese assets that the Japanese acquired before 1946 were confiscated and sold off.\n"
] |
how did we figure out that burning rocks would make metal?
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Metal working is *way* past caveman times.
We figured out fire, and we figured out how to make *hot* fire (which we needed to make strong pottery, which we needed for storage because we figured out agriculture which, incidentally, meant we needed to figure out writing).
A lot of this is, necessarily, speculative, but the likely scenario is someone put some metal in a hot fire and noticed it melted. Possibly people found free-lying metal deposits, or someone had rocks with a high degree of iron impurities.
A lot of stuff like this happens *by accident*, and then possibly someone *eventually* thinks of something to do with it.
|
[
"The traditional method of cracking rock was fire-setting, which involved heating the rock with fire to expand it. Once the rock was heated by fire it was quenched with water to break it. Fire-setting was one of the most effective rock breaking methods until 1867 when Alfred Nobel invented dynamite.\n",
"The constructive process used was the ancient one described by Diodorus Siculus. It consisted of stacking a pile of lumber against the rocky wall, and setting it on fire. The rock, burned by the flames, underwent a first process of calcination, after which it cracking and shattering gradually fragmented. The miners thereupon flooded the rock with large masses of a boiling water solution and vinegar thrown with force to disintegrate it even internally. At that point, the rock became sufficiently friable to be successfully attacked by hammers and picks that were forcefully inserted and acted in the cracks that had come to form earlier. \n",
"An early major use of blasting to remove rock occurred in 1843 when the British civil engineer William Cubitt used 18,000 lbs of gunpowder to remove a 400 foot high chalk cliff near Dover as part of the construction of the South Eastern Railway. About 400,000 cubic yards of chalk was displaced in an exercise that it was estimated saved the company six months time and £7,000 in expense.\n",
"The standard method for blasting rocks was to drill a hole to a considerable depth and deposit a charge of gunpowder at the further end of the hole and then fill the remainder of the hole with clay or some other soft mineral substance, well rammed, to make it as tight as possible. A wire laid in the hole during this process was then removed and replaced with a train of gunpowder. This train was ignited by a slow match, often consisting simply of brown paper smeared with grease, intended to burn long enough to allow the person who fires it enough time to reach a place of safety.\n",
"BULLET::::- Hard rocks containing ore veins such as quartzite were formerly broken down using fire-setting, which involved heating the rock face with a wood fire, then quenching with water to induce crack growth. It is described by Diodorus Siculus in Egyptian gold mines, Pliny the Elder, and Georg Agricola.\n",
"Agricola described mining methods which are now obsolete, such as fire-setting, which involved building fires against hard rock faces. The hot rock was quenched with water, and the thermal shock weakened it enough for easy removal. It was a dangerous method when used underground, and was made redundant by explosives.\n",
"The conversion of minerals to metal by means of fire was a process accompanied by rituals, magic formulas, and chanting to bring about the “birth of the metal.” At the foundation of a kiln at Palatca formed by a burnt out clay fireplace and several slabs of whetstone laid one on top of the other, probably round in shape, a clay vessel had been deposited. Close to the workshop, a large ritual area has been explored. Receptacles with offerings were placed in multiple hypostases next to ore-refining items (hand-mills, bronze items, ash, coal, etc.), underneath or on top of the whetstone slabs, head down or head up.\n"
] |
How did gunpowder weapons change siege tactics?
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They ended up not changing the strategic nature of siege warfare that much at all, except perhaps making the defender even stronger then they had been in previous centuries (how much so varies). Siege tactics, however, changed much more - but less than you'd expect.
There was a brief period from about the late 14th century to the early 15th century in which advanced cannon (corned powder, bronze barrels, iron shot) were sufficiently new that they let badly-built castles fall quickly, but it was fairly soon after their introduction that defensive countermeasures were introduced.
But even without those countermeasures, writers of the era noted that *the defender will always bring more guns to bear*. Any castle or fortification is going to be able to outrange and outgun any attacker, as the attacker will only have so many cannon that he can bring into firing range. When you combine this with how incredibly close the attacker needs to bring his weapons to have any effect on the massive walls, this creates a situation that is hugely tilted to the defender's advantage.
Defensive tactics became concerned with overlapping fields of fire, angled walls to deflect cannon balls, and secondary defenses to fall back too. The attacker would have to fight their way up a horrific outer killzone in which any given approach would have the defender's full firepower focused on them (usually by constructing trenches and earthworks inch by inch in a process that might take weeks or months), try their best to knock out the defender's well protected guns near the section of wall they sought to breach (if they didn't, any attack would be blown to shreds), make at least three breaches in the wall, and then launch a simultaneous assault - one that was usually unsuccessful.
[A comparison of pre and post gunpowder "ideal" fortifications from David Eltis' *The Military Revolution in Sixteenth Century Europe.*](_URL_1_)
It was unsuccessful because the defender at this point would have built the famous "semi-circle" around the breach points - a massed amount of artillery, arquebusiers, musketeers, and pikemen with their weapons aimed at the small breach in the wall and ensconced safely behind cover. When the enemy troops charged in, everyone would fire. And keep firing. Once the smoke cleared, the pikemen would charge the disoriented enemy and rout them - and the process would begin again.
Even the most outdated of castles could be decently well defended in this situation, by allowing the attacker to breach the walls and killing him when he got in. Custom designed fortifications were even more impossible to take - I'd recommend reading up on the Second Siege of Rhodes and the Siege of Malta to see exactly what faced an attacker who assaulted a fortified position with a determined defender.
**Bibliography:**
Eltis, David. *The Military Revolution in Sixteenth Century Europe.* New York: I.B. Tauris Publishers, 1998. Print.
Hall, Bert. *Weapons & Warfare in Renaissance Europe.* London: The Johns Hopkins Press Ltd., 1997. Print.
**Other comments:**
> It's my understanding that cannons were around before handheld gunpowder weapons, and were used in Europe as far back as the 1300s, so I'm hoping there must be some examples of sieges using these weapons.
A common opinion, but it's actually unclear. The current historiography has "handheld" (two man) weapons as the first to emerge, which makes sense when you think of how complicated it is to cast the barrel for/successfully use large gunpowder weapons.
> On a related note, I'm also interested in learning about military strategy and tactics from the introduction of gunpowder weapons up until the 1800s, so are there any books or other resources that would help me out? I'm looking for a fairly general overview of how gunpowder changed warfare, especially in Europe, and while I appreciate that this is a very big field I'm quite keen to learn about it, so any books or other resources would be a great help.
Ha, I came to this subreddit with almost the exact same question about 8 months ago. After I had learned a lot about the subject, [I answered my own question here] (_URL_0_) along with some other ones that I had. You might be interested.
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[
"The introduction of gunpowder affected the conduct of war significantly. Though employed by the English as early as the Battle of Crécy in 1346, firearms initially had little effect in the field of battle. It was through the use of cannons as siege weapons that major change was brought about; the new methods would eventually change the architectural structure of fortifications.\n",
"The introduction of gunpowder from the Asia at the end of this period revolutionized warfare. Formations of musketeers, protected by pikemen came to dominate open battles, and the cannon replaced the trebuchet as the dominant siege weapon.\n",
"Until the invention of gunpowder-based weapons (and the resulting higher-velocity projectiles), the balance of power and logistics definitely favored the defender. With the invention of gunpowder, the traditional methods of defence became less and less effective against a determined siege.\n",
"Until the invention of gunpowder-based weapons (and the resulting higher-velocity projectiles), the balance of power and logistics definitely favored the defender. With the invention of gunpowder, cannon and mortars and howitzers (in modern times), the traditional methods of defense became less effective against a determined siege.\n",
"A torsion siege engine is a type of artillery that utilizes torsion to launch projectiles. They were initially developed by the ancient Greeks, specifically Philip II of Macedon and Alexander the Great, and used through the Middle Ages until the development of gunpowder artillery in the 14th century rendered them obsolete.\n",
"In the latter half of the 17th century, the French engineer Sébastien Le Prestre de Vauban introduced a more systematic and scientific approach to attacking gunpowder fortresses, in a time when many field commanders \"were notorious dunces in siegecraft.\" Careful sapping forward, supported by enfilading ricochets, was a key feature of this system, and it even allowed Vauban to calculate the length of time a siege would take. He was also a prolific builder of bastion forts, and did much to popularize the idea of \"depth in defence\" in the face of cannon. These principles were followed into the mid-19th century, when changes in armaments necessitated greater depth defence than Vauban had provided for. It was only in the years prior to World War I that new works began to break radically away from his designs.\n",
"In the latter half of the 17th century, the French engineer Vauban introduced a more systematic and scientific approach to attacking gunpowder fortresses, in a time when many field commanders \"were notorious dunces in siegecraft.\" Careful sapping forward, supported by enfilading ricochet fire, was a key feature of this system, and it even allowed Vauban to calculate the length of time a siege would take. He was also a prolific builder of star forts, and did much to popularize the idea of \"depth defense\" in the face of cannon. These principles were followed into the mid-19th century, when changes in armaments necessitated greater depth defense than Vauban had provided for. It was only in the years prior to World War I that new works began to break radically away from his designs.\n"
] |
Palestine to Israel
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Do you mean, why did the State of Israel call itself “Israel” and not “Palestine”? The end of the British mandate on 14 May coincided precisely with the declaration of the State of Israel, which was made that evening. A few minutes later the United States recognized Israel. Recognition from other countries would arrive in the coming hours and days.
Other than that I’m not sure I understand the question?
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[
"The League of Nations assigned Palestine as a mandate to the UK in 1920. The British tried, but failed to stop large-scale Jewish immigration into the mandate. Britain returned it to UN control in 1947 and the UN divided Palestine into a Jewish state and an Arab state. Israel came into existence on May 14, 1948, fought off the Arab neighbors, and became a power in the region.\n",
"Although there is no State of Palestine, the Palestinian Territories have no specific, stand alone civil rights legislation that protects LGBT people from discrimination or harassment. While hundreds of gay Palestinians are reported to have fled to Israel because of the hostility they face in Palestine, they have also been subject to house arrest or deportation by Israeli authorities, on account of the inapplicability of the law of asylum to areas or nations in which Israel is in conflict. \n",
"Israel–Palestine relations refers to the political, security, economical and other relations between the State of Israel and the State of Palestine (as well as with the preceding Palestinian National Authority and earlier Palestinian Liberation Organization). Israel and the PLO began to engage in the late 1980s and early 1990s in what became to be the Israeli–Palestinian peace process, culminated with the Oslo Accords in 1993. Shortly after, the Palestinian National Authority was established and during the next 6 years formed a network of economic and security connections with Israel, being referred to as a fully autonomous region with self-administration. In the year 2000, the relations severely deteriorated with the eruption of the Second Intifada – a rapid escalation of the Israeli–Palestinian conflict. The events calmed down in 2005, with only partial reconciliation and cease fire. The situation became more complicated with the split of the Palestinian Authority in 2007, the violent split of Fatah and Hamas factions, and Hamas' takeover of the Gaza Strip. The Hamas takeover resulted in a complete rift between Israel and the Palestinian faction in the Gaza Strip, cancelling all relations except limited humanitarian supply.\n",
"In Palestine, there was a surge in attacks against the British mandate and occupation by Zionist organisations such as Irgun and the Stern Gang after the British attempted to limit Jewish immigration into Palestine. British military and other forces eventually withdrew in 1948 and the State of Israel was established on 14 May.\n",
"On 29 November the United Nations General Assembly voted to partition Palestine into an Arab state and a Jewish state (with Jerusalem becoming an international enclave). Amid public rejoicing in Jewish communities in Palestine, the Jewish Agency accepted the plan. The Palestinian Arab leadership and the Arab League rejected the decision and announced that they would not abide by it. Civil conflict between the Arabs and Jews in Palestine ensued immediately.\n",
"The Jewish Agency promised to the UN before 1948 that Palestinian Arabs would become full citizens of the State of Israel, and the Israeli declaration of independence invited the Arab inhabitants of Israel to \"full and equal citizenship\". In practice, Israel does not grant citizenship to the refugees, as it does to those Arabs who continue to reside in its borders. The 1947 Partition Plan determined citizenship based on residency, such that Arabs and Jews residing in Palestine but not in Jerusalem would obtain citizenship in the state in which they are resident. Professor of Law at Boston University Susan Akram, Omar Barghouti and Ilan Pappé have argued that Palestinian refugees from the envisioned Jewish State were entitled to normal Israeli citizenship based on laws of state succession.\n",
"Israel and the Palestine Liberation Organization signed the Gaza–Jericho Agreement, which established the Palestinian National Authority, a governing body for the interim period pending final status negotiations.\n"
] |
If measurement causes the wavefunction to collapse, and everything is constantly interacting with everything else in the universe via gravity, why haven't all wavefunctions collapsed all the time?
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Crudely, wavefunction collapse means the following. You allow your quantum system S to interact with a set of degrees of freedom M. The interaction entangles the state of S with the state of M, so that the probability distribution of some observable OS of S are correlated with observable OM of M. But perhaps you don't care about OM and only want the marginal distribution for OS. Averaging over OM produces an effective collapse: the probabilities governing future behavior of S now behave as though, at the time of interaction with M, OS took various values with probability set by the Born rule. This is what you would expect from classical probability theory, but differs from quantum mechanics because it eliminates the effects of interference between quantum mechanical amplitudes.
So, you might think that everything is interacting with gravity, and we don't care about the state of the gravitational field, so why doesn't averaging over it classicalize all probabilities? The reason is that gravity is weak: interactions with gravitons are rare. The quantum systems we look at are affected by gravity in the sense that their motion is influenced by the background gravitational field, but they are very unlikely to change the state of that field by entangling with a graviton.
|
[
"The measurement problem in quantum mechanics is the problem of how (or \"whether\") wave function collapse occurs. The inability to observe such a collapse directly has given rise to different interpretations of quantum mechanics and poses a key set of questions that each interpretation must answer.\n",
"The cluster of phenomena described by the expression \"wave function collapse\" is a fundamental problem in the interpretation of quantum mechanics, and is known as the measurement problem. The problem is deflected by the Copenhagen Interpretation, which postulates that this is a special characteristic of the \"measurement\" process. Everett's many-worlds interpretation deals with it by discarding the collapse-process, thus reformulating the relation between measurement apparatus and system in such a way that the linear laws of quantum mechanics are universally valid; that is, the only process according to which a quantum system evolves is governed by the Schrödinger equation or some relativistic equivalent.\n",
"However, neither the posited reality nor the proven and extraordinary accuracy of the wave function and quantum mechanics at small scales can imply or reasonably suggest the existence of a single wave function for the entire universe. Quantum mechanics breaks down wherever gravity becomes significant, because nothing in the wave function, or in quantum mechanics, predicts anything at all about gravity. And this is obviously of great importance on larger scales.\n",
"BULLET::::2. The measurement problem, which relates to what we call wavefunction collapse – the collapse of a quantum state into a definite measurement (i.e. a specific eigenstate of the wavefunction). The debate on whether this collapse actually occurs is a central problem in interpreting quantum mechanics.\n",
"In 1927, Werner Heisenberg used the idea of wave function reduction to explain quantum measurement. Nevertheless, it was debated, for if collapse were a fundamental physical phenomenon, rather than just the epiphenomenon of some other process, it would mean nature was fundamentally stochastic, i.e. nondeterministic, an undesirable property for a theory. \n",
"Some argue that the concept of the collapse of a \"real\" wave function was introduced by Heisenberg and later developed by John von Neumann in 1932. However, Heisenberg spoke of the wavefunction as representing available knowledge of a system, and did not use the term \"collapse\" per se, but instead termed it \"reduction\" of the wavefunction to a new state representing the change in available knowledge which occurs once a particular phenomenon is registered by the apparatus (often called \"measurement\").\n",
"In many-worlds, the subjective appearance of wavefunction collapse is explained by the mechanism of quantum decoherence, and this is supposed to resolve all of the correlation paradoxes of quantum theory, such as the EPR paradox and Schrödinger's cat, since every possible outcome of every event defines or exists in its own \"history\" or \"world\".\n"
] |
glass is not biodegradable, and will perhaps take even longer to decompose than plastic. why isn't it made out to be as big of an issue as plastic?
|
I believe that the answer lies in the fact that, if you crush up glass to extremely fine fragments, it is essentially sand. Plastic, as it breaks down, continues to float, pollute, and also mimics small water-borne organisms that larger organisms feed upon. Broken glass (sand) sinks, and essentially returns to the lifecycle of a rock.
|
[
"This composition of bioactive glass is comparatively soft in comparison to other glasses. It can be machined, preferably with diamond tools, or ground to powder. Bioglass has to be stored in a dry environment, as it readily absorbs moisture and reacts with it. Bioglass 45S5 is the first formulation of an artificial material that was found to chemically bond with bone. One of its main medical advantages is its biocompatibility, seen in its ability to avoid an immune reaction and fibrous encapsulation. Its primary application is the repair of bone injuries or defects too large to be regenerated by the natural process.\n",
"It was reported that roughly 50% of plastics are being utilized in disposable manufacturing processes such as packaging, agricultural films, and disposables, while 20 to 25 % was used for long-term infrastructure like pipes, coating for cables and structured materials and the remainder is used for durable moderate life consumer goods such as electronics, furniture, and vehicles. In general, plastic is considered to be durable and non-biodegradable hence making them difficult to decompose for at least a few decades with some lasting over hundreds or thousands of years. Judging from the domestic environmental factors, even some degradable plastics may still exist for a considerable period of time due to their degradation rate which is also influenced by factors such as the exposure of UV, oxygen, and temperature, whereas biodegradable plastics require the need of adequate microorganisms. Therefore, the rate of degradation in landfills and terrestrial, marine environments would tend to vary. \n",
"When these materials are commercially available, a significant benefit is expected due to their inherent biodegradable properties since it is wood. These materials are significantly more biodegradable than glass and plastics. Transparent wood it is also shatterproof. On the other hand, concerns may be relevant due to the use of non-biodegradable plastics for long lasting purpose, such as in building.\n",
"Compared with lucrative recycling of metal, and similar to the low value of glass, plastic polymers recycling is often more challenging because of low density and low value. There are also numerous technical hurdles to overcome when recycling plastic.\n",
"Bioactive glass offers good osteoconductivity and bioactivity, it can deliver cells and is biodegradable. This makes it an excellent candidate to be used in tissue engineering applications. Although this material is known to be brittle, it is still used extensively to enhance the growth of bone since new forms of bioactive glasses are based on borate and borosilicate compositions. Bioglass can also be doped with varying quantities of elements like copper, zinc, or strontium which can allow the growth and formation of healthy bone. The formation of neocartilage can also be induced with bioactive glass by using an in vitro culture of chondrocyte-seeded hydrogels and can serve as a subchondral substrate for tissue-engineered osteochondral constructs.\n",
"Glass can be recycled in the form of bottles and jars which are crushed down and then melted. Glass can be recycled infinitely because it does not lose any of its quality. It uses a lot less energy, fewer raw materials and produces less CO2 than manufacturing glass from scratch. The main difficulty with recycling glass is the need to remove the unwanted materials that contaminate it and avoiding the mixing of different colours.\n",
"Although biodegradable and degradable plastics have helped reduce plastic pollution, there are some drawbacks. One issue concerning both types of plastics is that they do not break down very efficiently in natural environments. There, degradable plastics that are oil-based may break down into smaller fractions, at which point they do not degrade further.\n"
] |
what is net nuetrality? what is being for it? against it? do we have it? trying ti get it?
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John Oliver made a video a few years back and one weeks ago that touches on the subject well. Basically with net neutrality, everybody's internet speed gets treated equally regardless of what websites, browsers, etc. you use.
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[
"Network neutrality (also net neutrality, Internet neutrality, or net equality) is the principle that Internet service providers and governments should treat all data on the Internet equally, not discriminating or charging differentially by user, content, site, platform, application, type of attached equipment, or mode of communication. Advocates of net neutrality have raised concerns about the ability of broadband providers to use their last mile infrastructure to block Internet applications and content (e.g. websites, services, and protocols), and even to block out competitors. Opponents claim net neutrality regulations would deter investment into improving broadband infrastructure and try to fix something that isn't broken. In April 2017, a recent attempt to compromise net neutrality in the United States is being considered by the newly appointed FCC chairman, Ajit Varadaraj Pai. The vote on whether or not to abolish net neutrality was passed on December 14, 2017, and ended in a 3-2 split in favor of abolishing net neutrality.\n",
"In the United States, net neutrality, the principle that Internet service providers (ISPs) treat all data on the Internet the same, and not discriminate, has been an issue of contention between network users and access providers since the 1990s. To elucidate the term \"net neutrality\", one can apply a metaphor that was given and illustrated by Michael Goodwin: In his illustration, he illustrates ISPs as the driveway that connects a home to the vast network of destinations on the internet, and net neutrality is the principle that prevents ISPs from slowing some traffic or charging a premium fee for other traffic.\n",
"In the United States, net neutrality, the principle that Internet service providers (ISPs) treat all data on the Internet the same, and not discriminate, has been an issue of contention between network users and access providers since the 1990s. To elucidate the term \"net neutrality\", one can apply a metaphor that was given and illustrated by Michael Goodwin: In his illustration, he illustrates ISPs as the driveway that connects a home to the vast network of destinations on the internet, and net neutrality is the principle that prevents ISPs from slowing some traffic or charging a premium fee for other traffic.\n",
"net 30 is a term that most business and municipalities (federal, state, and local) use in the United States. net 10 and net 15 are widely used as well, especially for contractors and service-oriented business (as opposed to those that deal with tangible goods) . Net 60 is not used as frequently due to its longer payment term.\n",
"Critics of net neutrality argue that data discrimination is desirable for reasons like guaranteeing quality of service. Bob Kahn, co-inventor of the Internet Protocol, called the term net neutrality a slogan and opposes establishing it, but he admits that he is against the fragmentation of the net whenever this becomes excluding to other participants. Vint Cerf, Kahn's co-founder of the Internet Protocol, explains the confusion over their positions on net neutrality, \"There’s also some argument that says, well you have to treat every packet the same. That’s not what any of us said. Or you can’t charge more for more usage. We didn’t say that either.\"\n",
"Net Neutrality is a term used by Tim Wu, an American lawyer from Columbia, that describes a major worry that permitting a monopoly in the Internet Service Provider or ISP could allow a major shift in the market that would give absolute power to broadband companies over internet applications. In January 2018 the Federal Communications Commission released an order titled \"Restoring Internet Freedom\" that calls for regulations to be removed from Obama era legislature that put into place rules to protect the average consumer from slow, overpriced and inaccessible internet connection. The order erases the need for total transparency from internet service providers to discourage unfair pricing and practices such as blocking or strangling lawful internet trafficking in favor of other sponsored or paid traffic from a third party.\n",
"La Quadrature du Net (\"Squaring of the Net\" in French) is a French advocacy group that promotes digital rights and freedoms of citizens. It advocates for French and European legislation to respect the founding principles of the Internet, most notably the free circulation of knowledge. \"La Quadrature du Net\" engages in public-policy debates concerning, for instance, freedom of speech, copyright, regulation of telecommunications and online privacy.\n"
] |
If autonomous cars become the norm, how much time and gas would we save on a typical weekly commute?
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I can't answer our question, but I can add some more sources of waste that would be eliminated by self-driving cars.
In theory, you would not longer need to stop at intersections. The computer algorithm could very quickly work out a way to get everyone through [with nobody stopping](_URL_0_).
In cases where the roadways are clear, there would be no traffic. The cars could communicate and get out of each-others' way so that none of them would need to brake or swerve unexpectedly.
The fuel costs of sitting at lights and sitting in traffic would be effectively eliminated.
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[
"Manually driven vehicles are reported to be used only 4–5% of the time, and being parked and unused for the remaining 95–96% of the time. Autonomous vehicles could, on the other hand, be used continuously after it has reached its destination. This could dramatically reduce the need for parking space. For example, in Los Angeles, 14% of the land is used for parking alone, equivalent to some 17,020,594 square meters. This combined with the potential reduced need for road space due to improved traffic flow, could free up tremendous amounts of land in urban areas, which could then be used for parks, recreational areas, buildings, among other uses; making cities more livable.\n",
"The world is currently experiencing the fastest wave of urbanization in human history, leading to unprecedented levels of traffic congestion. Superpedestrian’s vehicle technology was developed in direct response to rising urban populations and urban transportation demand. The current average car in the U.S. carries only 1.55 people per vehicle, but occupies enough road space to fit five. Many people assume that self-driving cars in the future will be used as shared vehicles, but research shows it is unlikely that autonomous vehicles will be shared for the majority of the time. Even with a steep discount in the price of a ride, surveys show only 52% of riders will be willing to share an autonomous vehicle. As a result, we are unlikely to meet future transportation needs without turning to micro-mobility - one-to-two person vehicles that enable individualized trips while taking up less road space.\n",
"The advantages of this technology are potentially enormous. Well-coordinated fully automatic driving will be much more efficient, with reduction in traffic jams and road accidents, which cost trillions per year in the US alone. Efficiency will also reduce energy consumption and thus pollution and climate change.\n",
"Car-sharing services address the longer-term solutions to consumer needs for better fuel savings and fewer traffic tie-ups and parking nightmares, to complement the environmental benefit of more open space and reduction of greenhouse gases. They may be thought of as a \"time-sharing\" system for cars. Consumers who drive less than 7,500 miles a year and do not need a car for work can save thousands of dollars annually by joining one of the many services springing up, including Zipcar (East Coast), I-GO Car (Chicago), and Hour Car (Twin Cities).\n",
"By reducing the (labor and other) cost of mobility as a service, automated cars could reduce the number of cars that are individually owned, replaced by taxi/pooling and other car-sharing services. This would also dramatically reduce the size of the automotive production industry, with corresponding environmental and economic effects. Assuming the increased efficiency is not fully offset by increases in demand, more efficient traffic flow could free roadway space for other uses such as better support for pedestrians and cyclists.\n",
"Self-driving cars are potentially beneficial to the environment. They can be programmed to navigate the most efficient route and reduce idle time, which could result in less fossil fuel consumption and greenhouse gas (GHG) emissions. The same could be said true for the heavy machinery used in the heavy industry. AI can see the path clearly, whereas humans are prone to occasional errors.\n",
"96.03% of occupied households had at least one motor vehicle, and 75.49% had two or more vehicles. For those employed, the average travel time to work was 36 minutes. 14.76% had travel times to work of 60 minutes or more.\n"
] |
considering how contagious vomiting bugs are like norovirus, why aren’t we always sick with them?
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Most extreme pathogens are caught early by food manufacturers. All of them are required to have up to date HACCP plans, food safety plans, and as of 2018 putting more emphasis on CoA of raw materials and doing due diligence on them. Check out the recalls. Almost all of these are 100% voluntary and require a lot effort and oversight. Look at blue bell. They got hit with listeria twice and after 8 years they are only just now coming back to the size they once were.
_URL_0_
Basic fact is that food companies, most of the time, catch these nasties before you get them. Of course norovirus is special because a sick worker at a tacobell wont take time off and then everything they look at is contaminated. Its rare that this happens and only spreads so far before everyone is healed. Also the immunity of norovirus varies from person to person but is usually a short amount of time.
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[
"Noroviruses are transmitted directly from person to person (62–84% of all reported outbreaks) and indirectly via contaminated water and food. They are extremely contagious, and fewer than twenty virus particles can cause an infection (some research suggests as few as five). Transmission can be aerosolized when those stricken with the illness vomit, and can be aerosolized by a toilet flush when vomit or diarrhea is present; infection can follow eating food or breathing air near an episode of vomiting, even if cleaned up. The viruses continue to be shed after symptoms have subsided and shedding can still be detected many weeks after infection.\n",
"Viruses (particularly rotavirus) and the bacteria \"Escherichia coli\" and \"Campylobacter\" species are the primary causes of gastroenteritis. There are, however, many other infectious agents that can cause this syndrome including parasites and fungus. Non-infectious causes are seen on occasion, but they are less likely than a viral or bacterial cause. Risk of infection is higher in children due to their lack of immunity. Children are also at higher risk because they are less likely to practice good hygiene habits. Children living in areas without easy access to water and soap are especially vulnerable.\n",
"The virus is unable to infect humans in the way it does insects, because human stomachs are acid-based and NPV requires an alkaline digestive system in order to replicate. It is possible for the virus crystals to enter human cells, but not to replicate to the point of causing illness.\n",
"Rotavirus, norovirus, adenovirus, and astrovirus are known to cause viral gastroenteritis. Rotavirus is the most common cause of gastroenteritis in children, and produces similar rates in both the developed and developing world. Viruses cause about 70% of episodes of infectious diarrhea in the pediatric age group. Rotavirus is a less common cause in adults due to acquired immunity. Norovirus is the cause in about 18% of all cases.\n",
"Although they are considered harmless, some cases of myiasis caused by the larvae of this insect are reported in the literature, at the nasal, intestinal and urinary levels but are often associated with very poor sanitary conditions and bad hygiene habits.\n",
"The most commonly encountered strains of ANTI have only subtle effects, and thus can exist and spread indefinitely without being noticed until an antivirus application is run. Due to a bug in the virus, it cannot spread if MultiFinder is running, which prevents it from infecting System 7 and later versions of Mac OS as well as System 5 and 6 running MultiFinder.\n",
"Symptoms often include vomiting, fever, and aches, and may include diarrhea. Bouts of vomiting can be repeated with an extended delay in between, because even if infected food was eliminated from the stomach in the first bout, microbes, like bacteria, (if applicable) can pass through the stomach into the intestine and begin to multiply. Some types of microbes stay in the intestine, some produce a toxin that is absorbed into the bloodstream, and some can directly invade deeper body tissues.\n"
] |
why are credit cards and credit so important? what's wrong with just a debt card?
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Debit cards are fine, you just don't build credit with them. You're using cash you actually have in an account, as opposed to using a credit line.
Credit is important because at some point in life, you will invariably need money you don't have. For example, you may need to take out a loan for a house, finance a car, etc. If you're doing business in an individual capacity or as the representative of a company, it also helps to have a good credit score for much the same reason. A bank is more likely to lend to a business if its guarantors have good credit.
For my part, I think it's advisable to build credit to a point where you can shred the cards and go cash-only in like in ye olden tymes. I've read studies saying you spend (waste) less money that way, and nothing's quite as baller as paying for everything in bills like a prohibition-era gangster.
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[
"Declines in credit card debt are often misinterpreted because they fail to include information about charge-offs. The possible causes for a decline in credit card debt are consumers paying down their debt, credit card companies writing charged-off debt off their books, or a combination of the two. Inclusion of charged-off debt can therefore significantly impact debt trends and the characterization of a nation's financial health. For example, the $10.3 billion decrease in outstanding credit card debt in Q3 2010 relative to the previous quarter might at first glance seem to be a significant consumer pay down. However, considering that the Q3 credit card charge-off rate was $16.9 billion, consumers actually increased their overall debt by $6.6 billion during this quarter.\n",
"This fact has necessitated the need for almost every citizen to have a credit card. However, many credit cards companies manage their perception to make sure that people continue to need credit cards, and control their perception so that many people do not fully understand what they are getting into. However, the fact that the average household in the United States is in over fifteen thousand dollars worth of debt never reaches the widespread public. Instead, they publicize how they will help if a card gets stolen, or that they have the lowest interest percentage compared to the other major competitors. But no company tells their customers that the promoted interest rate more than doubles if they do not pay the minimum balance on time. For instance, Discover's interest rate increases to 18.99% after the first minimum balance is not paid on time.\n",
"Secured credit cards are an option to allow a person with a poor credit history or no credit history to have a credit card which might not otherwise be available. They are often offered as a means of rebuilding one's credit. Fees and service charges for secured credit cards often exceed those charged for ordinary non-secured credit cards. For people in certain situations, (for example, after charging off on other credit cards, or people with a long history of delinquency on various forms of debt), secured cards are almost always more expensive than unsecured credit cards.\n",
"It is then not surprising why credit cards are the major source of payments for consumers in e-commerce. They provide a remedy that reverses all transactions when a fraudulent use has occurred, or when there is a violation of the contract terms. However this method has limitations; it offers one single remedy (the return of the payment), and not all disputes imply a breach of contract or fraud.\n",
"Sources of credit such as credit cards enable overspending by allowing consumers to spend beyond their income. Financial counselors advise indebted consumers to avoid buying goods on credit and even to cut up their credit cards.\n",
"This opinion has stood in stark contrast to the ever-increasing U.S. consumers’ love of credit cards, and their increasing debt. In 2012, those consumers had an average 3.7 cards and an unpaid balance of over $5,600. Meanwhile, credit card debt totaled nearly $800 billion.\n",
"According to a 2004 \"Healthcare Financial Management\" web page, credit card debt comprises seventy percent of the accounts sold to debt buyers, followed by automobile loans, telecommunications debt and retail accounts. \n"
] |
Does pollen carry or assist the spread of illness?
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Pollen can act as a significant vector for viruses (_URL_0_ you can only see the abstract, but that's enough to know that pollen is a viral vector), however pollen doesn't actually increase the amount of pathogenic particles leaving someone with a transferable disease unless they are allergic.
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[
"The pollen which causes hay fever varies from person to person and from region to region; generally speaking, the tiny, hardly visible pollens of wind-pollinated plants are the predominant cause. Pollens of insect-pollinated plants are too large to remain airborne and pose no risk.\n",
"Dunbar devised techniques for collecting pure pollen, because sample contamination had previously led to unverifiable results. He developed methodologies for testing patients' sensitivity to certain pollens by minuscule exposure to pollen via their eyes or nasal passages, By using high-quality lab techniques, he was able to eliminate a number of theories about \"hay fever\" that were current in the late 1800s. Dunbar determined that it was the dried cat saliva on cat hair that caused the allergic reaction. With regard to grass pollen, Dunbar identified the albumin fraction as the active toxin, discovered changes in the blood that accompanied exposure to the pollen, and was able to grade individual's relative susceptibility to each type of pollen. Much of his work on allergies is summed up in his 1913 publication \"The present state of knowledge of hay fever\".\n",
"Nasal allergy to pollen is called pollinosis, and allergy specifically to grass pollen is called hay fever. Generally, pollens that cause allergies are those of anemophilous plants (pollen is dispersed by air currents.) Such plants produce large quantities of lightweight pollen (because wind dispersal is random and the likelihood of one pollen grain landing on another flower is small), which can be carried for great distances and are easily inhaled, bringing it into contact with the sensitive nasal passages.\n",
"Bee pollen has been touted by herbalists as a treatment for a variety of medical conditions, but there is no good evidence that bee pollen has any health benefits other than as a source of nutrition. Potential risks of consuming bee pollen include contamination by fungal mycotoxins, pesticides, or toxic metals. Bee pollen is safe for short term use, but for those with pollen allergies, allergic reactions may occur (shortness of breath, hives, swelling, and anaphylaxis). Bee pollen is not safe for pregnant women and should not be used during breastfeeding. The Food and Drug Administration has warned against the use of some bee pollen products because they are adulterated with unapproved drugs including sibutramine and phenolphthalein.\n",
"The type of allergens in the pollen is the main factor that determines whether the pollen is likely to cause hay fever. For example, pine tree pollen is produced in large amounts by a common tree, which would make it a good candidate for causing allergy. It is, however, a relatively rare cause of allergy because the types of allergens in pine pollen appear to make it less allergenic. Instead the allergen is usually the pollen of the contemporary bloom of anemophilous ragweed (\"Ambrosia\"), which can drift for many miles. Scientists have collected samples of ragweed pollen 400 miles out at sea and 2 miles high in the air. A single ragweed plant can generate a million grains of pollen per day.\n",
"In 2005, a team of scientists led by the National Institute of Beekeeping in Bologna, Italy, found pollen obtained from seeds dressed with imidacloprid contain significant levels of the insecticide, and suggested the polluted pollen might cause honey bee colony death. Analysis of maize and sunflower crops originating from seeds dressed with imidacloprid suggest large amounts of the insecticide will be carried back to honey bee colonies. Sublethal doses of imidacloprid in sucrose solution have also been documented to affect homing and foraging activity of honey bees. Imidacloprid in sucrose solution fed to bees in the laboratory impaired their communication for a few hours. Sublethal doses of imidacloprid in laboratory and field experiment decreased flight activity and olfactory discrimination, and olfactory learning performance was impaired.\n",
"Allergic rhinitis triggered by the pollens of specific seasonal plants is commonly known as \"hay fever\", because it is most prevalent during haying season. However, it is possible to have allergic rhinitis throughout the year. The pollen that causes hay fever varies between individuals and from region to region; in general, the tiny, hardly visible pollens of wind-pollinated plants are the predominant cause. Pollens of insect-pollinated plants are too large to remain airborne and pose no risk. Examples of plants commonly responsible for hay fever include:\n"
] |
How did scientists recreate the 1918 Influenza Virus?
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Scientists were able to determine the genetic sequence of the 1918 virus using samples from a woman who had died of the virus and was buried in permafrost. Then, they used the sequence to rebuild the virus, likely by expressing the genome within a cell, which would produce viral proteins that assembled into infectious viruses. This was done in 2005 by the CDC. The primary goal of recreating this virus is to study what made it more deadly than current viruses, as well as what made it a pandemic. There is also a hypothesis that it is safer to work with, because it has similarities to the H1N1 virus that many people were exposed to or inoculated against in 2009, and thus would not act like a pandemic flu if it were released accidentally. Hopefully, this is never tested and remains a hypothesis.
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[
"In early 2004, David Lipman, Lone Simonsen, Steven Salzberg, and a consortium of other scientists wrote a proposal to begin sequencing large numbers of influenza viruses at The Institute for Genomic Research (TIGR). Prior to this project, only a handful of flu genomes were publicly available. Their proposal was approved by the National Institutes of Health (NIH), and would later become the IGSP. New technology development led by Elodie Ghedin began at TIGR later that year, and the first publication describing 100 influenza genomes appeared in 2005 in the journal Nature \n",
"The February 6, 2004 edition of \"Science\" magazine reported that two research teams, one led by Sir John Skehel, director of the National Institute for Medical Research in London, another by Professor Ian Wilson of The Scripps Research Institute in San Diego, had managed to synthesize the hemagglutinin protein responsible for the flu outbreak of 1918. They did this by piecing together DNA from a lung sample from an Inuit woman buried in the Alaskan tundra and a number of preserved samples from American soldiers of the First World War. The teams had analyzed the structure of the gene and discovered how subtle alterations to the shape of a protein molecule had allowed it to move from birds to humans with such devastating effects.\n",
"Starting in the late 1940s, Hirst carried out pioneering research into the genetics of animal viruses. His team built on Frank Macfarlane Burnet's work on recombination in influenza virus, carrying out a series of experiments that led Hirst to conclude in 1962 that influenza's genome must consist of several separate fragments, \"a truly revolutionary idea at the time,\" according to R. Walter Schlesinger and Allan Granoff. Influenza viruses are now known to have eight such segments, and the segmentation of its genome facilitates the exchange of segments between different influenza viruses, causing antigenic shift which can result in pandemics. Segmented genomes are also found in many other viruses.\n",
"The first influenza virus to be isolated was from poultry, when in 1901 the agent causing a disease called \"fowl plague\" was passed through Chamberland filters, which have pores that are too small for bacteria to pass through. The etiological cause of influenza, the virus family Orthomyxoviridae, was first discovered in pigs by Richard Shope in 1931. This discovery was shortly followed by the isolation of the virus from humans by a group headed by Patrick Laidlaw at the Medical Research Council of the United Kingdom in 1933. However, it was not until Wendell Stanley first crystallized tobacco mosaic virus in 1935 that the non-cellular nature of viruses was appreciated.\n",
"Although the duo had perhaps isolated the influenza virus (which they nevertheless referred to as an atypical bacterium called Bacterium pneumosintes), other researchers could not reproduce their results.\n",
"An effort to recreate the 1918 flu strain (a subtype of avian strain H1N1) was a collaboration among the Armed Forces Institute of Pathology, the USDA ARS Southeast Poultry Research Laboratory and Mount Sinai School of Medicine in New York City. The effort resulted in the announcement (on 5 October 2005) that the group had successfully determined the virus's genetic sequence, using historic tissue samples recovered by pathologist Johan Hultin from a female flu victim buried in the Alaskan permafrost and samples preserved from American soldiers.\n",
"In a series of papers the team published the complete genome of the 1918 influenza virus. The work was funded by the Veteran's Administration and the Department of Defense. The completion of the genome in 2005 was numbered among the “breakthroughs of the year” by \"Science\" and was elected as \"paper of the year\" by \"Lancet \".\n"
] |
what does hydrogen peroxide do to earwax chemically that makes it easier to remove?
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It doesn't do anything chemically to the earwax, other than possibly diluting it. It works mechanically. The bubbles help loosen the wax. The bubbles are caused by an enzyme called catalase that exists in the dead skin cells in the wax. This enzyme rapidly breaks down the hydrogen peroxide, releasing bubbles of oxygen.
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[
"Hydrogen peroxide - urea is mainly used as a disinfecting and bleaching agent in cosmetics and pharmaceuticals. As a drug, this compound is used in some preparations for the whitening of teeth. It is also used to relieve minor inflammation of gums, oral mucosal surfaces and lips including canker sores and dental irritation, and to emulsify and disperse earwax.\n",
"Hydrogen peroxide can be used as an oxidizing mouthwash (e.g. Peroxyl, 1.5%). It kills anaerobic bacteria, and also has a mechanical cleansing action when it froths as it comes into contact with debris in mouth. It is often used in the short term to treat acute necrotising ulcerative gingivitis. Side effects with prolonged use might occur, including hypertrophy of the lingual papillae.\n",
"A 1979 double-blind crossover study suggests that hydrogen peroxide, which is released during the use of this product, may prevent or retard colonization and multiplication of anaerobic bacteria, such as those that inhabit oral wounds.\n",
"A recent double-blind crossover study suggests that hydrogen peroxide, which is released during the use of this product, may prevent or retard colonization and multiplication of anaerobic bacteria, such as those that inhabit oral wounds.\n",
"Hydrogen peroxide is seen as an environmentally safe alternative to chlorine-based bleaches, as it degrades to form oxygen and water and it is generally recognized as safe as an antimicrobial agent by the U.S. Food and Drug Administration (FDA).\n",
"The majority of hydrogen peroxide solutions are 3% hydrogen peroxide. This enables the solution to break down any proteins that coat the contacts after a long period of use. Hydrogen peroxide is always used alongside a neutralizing product. The intention is to prevent the hydrogen peroxide from contact with the eye, which could damage the corneal cells in the epithelium. While this would not result in permanent damage, it can cause an intense burn that can linger even after an eye rinse. Burned cells heal very quickly once the natural tear film is restored.\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"
] |
growing plants indoors with non-solar light...help understanding plant needs / physics
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Hahaha, c'mon man, just say it. "I'm growing pot, help plz?"
Even if you aren't though, you might just want to go to /r/trees and ask for growing tips. Same function really.
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[
"When planning an indoor garden it is important to choose plants with light requirements that are conducive in homes. To maximize a plants sun exposure, place it in a room that receives high amounts of natural light. Artificial lights are an alternative if the natural lighting in a room is insufficient, and they can help plants reach their maximum growth potential. Indoor plants thrive on consistency. Stable temperatures (65–75 degrees Fahrenheit), consistent lighting, and regular watering are all beneficial for indoor plants.\n",
"Grow lights either attempt to provide a light spectrum similar to that of the sun, or to provide a spectrum that is more tailored to the needs of the plants being cultivated. Outdoor conditions are mimicked with varying colour, temperatures and spectral outputs from the grow light, as well as varying the intensity of the lamps. Depending on the type of plant being cultivated, the stage of cultivation (e.g. the germination/vegetative phase or the flowering/fruiting phase), and the photoperiod required by the plants, specific ranges of spectrum, luminous efficacy and colour temperature are desirable for use with specific plants and time periods.\n",
"Plants grown under HPS lights tend to elongate from the lack of blue/ultraviolet radiation. Modern horticultural HPS lamps have a much better adjusted spectrum for plant growth. The majority of HPS lamps while providing good growth, offer poor color rendering index (CRI) rendering. As a result, the yellowish light of an HPS can make monitoring plant health indoors more difficult. CRI isn't an issue when HPS lamps are used as supplemental lighting in greenhouses which make use of natural daylight (which offsets the yellow light of the HPS).\n",
"In tests conducted by Philips Lighting on LED grow lights to find an optimal light recipe for growing various vegetables in greenhouses, they found that the following aspects of light affects both plant growth (photosynthesis) and plant development (morphology): light intensity, total light over time, light at which moment of the day, light/dark period per day, light quality (spectrum), light direction and light distribution over the plants. However it's noted that in tests between tomatoes, mini cucumbers and bell peppers, the optimal light recipe was not the same for all plants, and varied depending on both the crop and the region, so currently they must optimize LED lighting in greenhouses based on trial and error. They've shown that LED light affects disease resistance, taste and nutritional levels, but as of 2014 they haven't found a practical way to use that information.\n",
"The three most common varieties of artificial lighting for indoor growing are high-intensity discharge lamps (the most prevalent for this application being: sodium-vapor lamps for flowering and metal halide lamps for growing), compact fluorescent lamps, and traditional fluorescent lamps. Full spectrum indoor LED grow lights are becoming more common in grow rooms due to their low energy requirements and very low heat output.\n",
"Grow lights are used for horticulture, indoor gardening, plant propagation and food production, including indoor hydroponics and aquatic plants. Although most grow lights are used on an industrial level, they can also be used in households.\n",
"While sunlight is not always easily controlled by the gardener, it is an important element of garden design. The amount of available light is a critical factor in determining what plants may be grown. Sunlight will, therefore, have a substantial influence on the character of the garden. For example, a rose garden is generally not successful in full shade, while a garden of hostas may not thrive in hot sun. As another example, a vegetable garden may need to be placed in a sunny location, and if that location is not ideal for the overall garden design goals, the designer may need to change other aspects of the garden.\n"
] |
flight, how does it work?
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Ever stuck your hand out a car window and tilted it? You feel a force pushing your hand up or down, this is Lift. Lift counteracts Weight from gravity and enables flight.
While the shape of the wing provides some lift, the majority of it comes from the angle that the wing is going into the wind at (angle of attack). If you want to go up then you tilt the nose up, if you want to go down you tilt the nose down just like angling your hand out the car window.
But tilting your hand also creates a force which pushes it backwards, this is called Drag. To counteract drag you need Thrust which we get from engines that drive propellers or giant fans(jet engines).
And those are the four basic forces of flight - Lift, Weight, Drag, and Thrust. If you've got enough Lift to overcome your Weight then you can fly but it generally takes high speed to generate that lift so you need enough Thrust to overcome the Drag.
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[
"Flight is the process by which an object moves through an atmosphere (or beyond it, as in the case of spaceflight) without contact with the surface. This can be achieved by generating aerodynamic lift associated with propulsive thrust, aerostatically using buoyancy, or by ballistic movement.\n",
"Flight is the process by which an object moves through or beyond the sky (as in the case of spaceflight), whether by generating aerodynamic lift, propulsive thrust, aerostatically using buoyancy, or by ballistic movement, without any direct mechanical support from the ground. The engineering aspects of flight are studied in aerospace engineering which is subdivided into aeronautics, which is the study of vehicles that travel through the air, and astronautics, the study of vehicles that travel through space, and in ballistics, the study of the flight of projectiles. While human beings have been capable of flight via hot air balloons since 1783, other species have used flight for significantly longer. Animals, such as birds, bats, and insects are capable of flight. Spores and seeds from plants use flight, via use of the wind, as a method of propagating their species.\n",
"Takeoff is the phase of flight in which an aircraft goes through a transition from moving along the ground (taxiing) to flying in the air, usually starting on a runway. For balloons, helicopters and some specialized fixed-wing aircraft (VTOL aircraft such as the Harrier), no runway is needed. Takeoff is the opposite of landing.\n",
"For aircraft that take off horizontally, this usually involves starting with a transition from moving along the ground on a runway. For balloons, helicopters and some specialized fixed-wing aircraft (VTOL aircraft such as the Harrier), no runway is needed. Takeoff is the opposite of landing.\n",
"Successful air navigation involves piloting an aircraft from place to place without getting lost, not breaking the laws applying to aircraft, or endangering the safety of those on board or on the ground. Air navigation differs from the navigation of surface craft in several ways; Aircraft travel at relatively high speeds, leaving less time to calculate their position en route. Aircraft normally cannot stop in mid-air to ascertain their position at leisure. Aircraft are safety-limited by the amount of fuel they can carry; a surface vehicle can usually get lost, run out of fuel, then simply await rescue. There is no in-flight rescue for most aircraft. Additionally, collisions with obstructions are usually fatal. Therefore, constant awareness of position is critical for aircraft pilots.\n",
"Flight occurs when a decision is taken after the problem goes away. This happens when problems are attached to choice opportunities for a period of time and exceed the energy of their respective decision makers to stay focused on the problem. The original problem may then move to another choice arena. Examples are tabling, or sending decisions to subcommittees, where the problems may not get attached to solutions.\n",
"Landing is the last part of a flight, where a flying aircraft or spacecraft (or animals) returns to the ground. When the flying object returns to water, the process is called alighting, although it is commonly called \"landing\" and \"touchdown\" as well. A normal aircraft flight would include several parts of flight including taxi, takeoff, climb, cruise, descent and landing.\n"
] |
how does fat and energy work? how is it that you burn fat by exercising, but you can have fat and still be out of energy. if i just stop eating, why isn't it that i can be full of energy until my body is out of fat?
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This will be a little complicated.
Fat is energy, but it's not immediately usable as energy; since cells are the smallest living unit, fat has to be broken down into parts that the cells can use before it is actually usable. Of course, breaking down molecules takes time, as well.
Breaking down the fat releases the usable parts (glucose) into the bloodstream. Your body automatically tries to keep the blood glucose level steady. Why? Because too much blood glucose is inefficient; too little blood glucose is dangerous.
So when you exercise, you are using up blood glucose. Once the level gets too low, your body will start breaking things down to bring the levels back up. It starts with carbohydrates, because those are easily broken down into glucose. Once those are almost gone, then it starts breaking down the fats. If the fats are running out, then it will turn to proteins and muscle. Light exercise will burn up the carbohydrates. Strenuous or extended exercise will start burning up fats. Flight-or-fight, life-or-death situations will most likely cut into your muscles and proteins.
Because of this order of energy consumption, your body doesn't like to use too much energy. It doesn't like to start burning up fat, because that is the "reserve" energy that the body can use before it goes into full panic mode (burning muscle).
So when you exercise a lot, your body will grudgingly start breaking up fat. That's why you have to do a lot of strenuous exercise to lose fat; you have to force the body to use its reserve energy.
The other side of this coin is energy storage. After a meal, when your blood is full of glucose, your body will start storing the energy away for a rainy day. Your body will start turning the extra blood glucose into fats, and storing those fats away for later use. That's why you don't have a huge burst of energy after a meal; all that extra glucose that you are digesting is being turned into fats.
|
[
"Adipose tissue, commonly known as fat, is a depository for energy in order to conserve metabolic homeostasis. As the body takes in energy in the form of glucose, some is expended, and the rest is stored as glycogen primarily in the liver, muscle cells, or fat.\n",
"The body's primary source of energy is glucose; however, when all the glucose in the body has been expended, a normal body digests fats. Individuals with a fatty-acid metabolism disorder are unable to metabolize this fat source for energy, halting bodily processes. Most individuals with a fatty-acid metabolism disorder are able to live a normal active life with simple adjustments to diet and medications.\n",
"When the body is expending more energy than it is consuming (e.g. when exercising), the body's cells rely on internally stored energy sources, such as complex carbohydrates and fats, for energy. The first source to which the body turns is glycogen (by glycogenolysis). Glycogen is a complex carbohydrate, 65% of which is stored in skeletal muscles and the remainder in the liver (totaling about 2,000 kcal in the whole body). It is created from the excess of ingested macronutrients, mainly carbohydrates. When glycogen is nearly depleted, the body begins lipolysis, the mobilization and catabolism of fat stores for energy. In this process fats, obtained from adipose tissue, or fat cells, are broken down into glycerol and fatty acids, which can be used to generate energy. The primary by-products of metabolism are carbon dioxide and water; carbon dioxide is expelled through the respiratory system.\n",
"Diet itself helps to increase calorie burning by boosting metabolism, a process further enhanced while gaining more lean muscle. An aerobic exercise program can burn fat and increase the metabolic rate.\n",
"Fat is an important foodstuff for many forms of life, and fats serve both structural and metabolic functions. They are a necessary part of the diet of most heterotrophs (including humans) and are the most energy dense, thus the most efficient form of energy storage.\n",
"Ordinarily, the body responds to reduced energy intake by burning fat reserves and consuming muscle and other tissues. Specifically, the body burns fat after first exhausting the contents of the digestive tract along with glycogen reserves stored in liver cells and after significant protein loss . After prolonged periods of starvation, the body uses the proteins within muscle tissue as a fuel source.\n",
"With use, muscles consume energy derived from both fat and glycogen. Due to the large size of leg muscles, walking, running, and cycling are the most effective means of exercise to reduce body fat. Exercise affects macronutrient balance. During moderate exercise, equivalent to a brisk walk, there is a shift to greater use of fat as a fuel. To maintain health, the American Heart Association recommends a minimum of 30 minutes of moderate exercise at least 5 days a week.\n"
] |
how does accutane exactly work, what does it do with the body system, and why do results vary from person to person?
|
The Accutane molecule is similar in shape to Vitamin A. It stops sebaceous glands from working. Think of it as turning off the faucet that pumps the gunk into the acne. It doesn't work for everyone because it doesn't work for every time of acne. It works best for the big nodular acne, because that is mostly caused by overproduction from sebaceous glands. Other types of acne have different causes.
I don't quite understand what you mean by it affecting the body system.
I hope this helps.
|
[
"The substance acts on mucus membranes, restoring the physiological clearance mechanisms of the respiratory tract (which play an important role in the body’s natural defence mechanisms) through several mechanisms, including breaking up phlegm, stimulating mucus production, and stimulating synthesis and release of surfactant by type II pneumocytes. Surfactant acts as an anti-glue factor by reducing the adhesion of mucus to the bronchial wall, in improving its transport and in providing protection against infection and irritating agents.\n",
"Troxipide enhances mucosal blood flow, which is the secondary defense barrier of gastric mucosa that supplies nutrients and oxygen to the epithelium, and removes, dilutes and neutralizes toxic substances that have diffused into the mucosa from the lumen. The increment in mucosal blood flow with troxipide is more pronounced in the gastric antrum than in the gastric corpus.\n",
"Estradiol can be taken by a variety of different routes of administration. These include oral, buccal, sublingual, intranasal, transdermal (gels, creams, patches), vaginal (tablets, creams, rings, suppositories), rectal, by intramuscular or subcutaneous injection (in oil or aqueous), and as a subcutaneous implant. The pharmacokinetics of estradiol, including its bioavailability, metabolism, biological half-life, and other parameters, differ by route of administration. Likewise, the potency of estradiol, and its local effects in certain tissues, most importantly the liver, differ by route of administration as well. In particular, the oral route is subject to a high first-pass effect, which results in high levels of estradiol and consequent estrogenic effects in the liver and low potency due to first-pass hepatic and intestinal metabolism into metabolites like estrone and estrogen conjugates. Conversely, this is not the case for parenteral (non-oral) routes, which bypass the intestines and liver.\n",
"Estradiol can be taken by a variety of different routes of administration. These include oral, buccal, sublingual, intranasal, transdermal (gels, creams, patches), vaginal (tablets, creams, rings, suppositories), rectal, by intramuscular or subcutaneous injection (in oil or aqueous), and as a subcutaneous implant. The pharmacokinetics of estradiol, including its bioavailability, metabolism, biological half-life, and other parameters, differ by route of administration. Likewise, the potency of estradiol, and its local effects in certain tissues, most importantly the liver, differ by route of administration as well. In particular, the oral route is subject to a high first-pass effect, which results in high levels of estradiol and consequent estrogenic effects in the liver and low potency due to first-pass hepatic and intestinal metabolism into metabolites like estrone and estrogen conjugates. Conversely, this is not the case for parenteral (non-oral) routes, which bypass the intestines and liver.\n",
"Estradiol can be taken by mouth, held under the tongue, as a gel or patch that is applied to the skin, in through the vagina, by injection into muscle or fat, or through the use of an implant that is placed into fat, among other routes.\n",
"Estradiol can be taken by mouth, held under the tongue, as a gel or patch that is applied to the skin, in through the vagina, by injection into muscle or fat, or through the use of an implant that is placed into fat, among other routes.\n",
"Rectal administration uses the rectum as a route of administration for medication and other fluids, which are absorbed by the rectum's blood vessels, and flow into the body's circulatory system, which distributes the drug to the body's organs and bodily systems.\n"
] |
What really happened in melee combat?
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It really varies wildly based on culture, time, technology, organization, numbers, etc. Despite being from a post-gunpowder era, I feel you might be interested in a clash of pikes.
Drawing from my study, the early 16th century, if serious combat was joined it was likely to be a clash of equally matched pike formations. If one side had a serious advantage due to flanking, supporting gunfire, or other factors then the combat was likely to end quickly in a rout or retreat (or massacre). Otherwise, you'd have the famous "bad war" or "push of pike".
While one side might brace to receive a charge, it was more common for both to charge as soon as they were close enough to try and gain an advantage in the ensuing melee. The two formations would slam together, and pikes would pierce people and throw them to the ground. The armored front ranks might fare surprisingly well, but the pikes would reach back to the greener troops behind the first few ranks who would have less complete suits of plate and slice into their flesh. The formations would push and shove against each other in a horrid mass of pikes, men, and mud as the earth beneath their feet stirred into dust. Soldiers further back would try and drag their wounded friends away from the melee, and humanely dispatch mortally wounded enemies with a quick thrust of a sidearm (dagger or sword), but there was serious risk of being trampled to death if wounded.
Additional pike formations might join the clash or create others nearby, but eventually enough time would pass that auxiliary infantry would be able to join, or they might have already been attached to the formation. These are dedicated troops that are meant to turn the tide in a push of pike, and whichever formation had included more of them would have a serious advantage. Soldiers of the Holy Roman Empire might bring along two-handed swordsmen, who would try to hack their way into the enemy formation or (maybe) cut the enemy's pikes into pieces. The Swiss would have their halberdiers join their pikemen in pushing, but the halberds could be drawn backwards and forwards to saw through armor and into men's bodies. The Spanish would send fighter in plate armor, steel shields, and nimble swords to slip past/under/to the side of enemy pikes and stab at the men in the formation - even sliding/wriggling over the ground if it was muddy enough.
This screaming, cursing, struggling mass of men would continue shoving against each other until one side had enough and fled, often dropping their pikes in the process, or disengaged and retreated. This could be caused by flank attacks by cavalry or other infantry, the soldiers suffering too much psychological trauma to go on, or point blank arquebus and/or crossbow fire breaking their cohesion. Officers would seek to prevent this by quickly directing troops to gaps, keeping an eye out for flankers or missile troops, and rallying the troops to keep fighting.
During these battles, small units of arquebusiers or crossbowmen would often be intermingled with the formation and fire point blank into the enemy's faces. In the Battle of Ceresole, the French included an entire line of arquebusiers right behind the first rank of Swiss pikemen. They caused a dreadful slaughter among the opposing Landschneckt, but must have not enjoyed it when the lines met. Regardless, bullets and crossbow bolts would be flying into the front ranks and flanks, who would trust to luck and their armor to deflect the worst of the damage.
You can see how critical morale would be in this kind of warfare - a single man dropping his pike and fleeing could be enough to start a rout. "Bad war" was deeply feared by all soldiers, and pike formations tried their best to ensure that the clash was on terms that was very favorable to them - but the realities of combat meant that matched encounters of pikes occurred in most major battles.
|
[
"Melee combat is split into two phases. In the first phase, the player approaches an enemy and attempts to punch them, as with most beat 'em up games. If the player successfully hits the enemy, the game enters attack mode. If the player misses and is instead attacked themselves, the game enters defense mode. Both modes are identical insofar as the player must enter a sequence of button presses before the timer runs out. If they do so correctly, they will successfully attack or block the enemy. If they run out of time or press the wrong buttons, they will be attacked or blocked themselves. Players can also push enemies away and attempt to flee from combat, and they can attempt to avoid combat altogether by sneaking up behind enemies and knocking them out.\n",
"Melee tournaments can include a number of combatants taking to the field. Especially at large events such as Pennsic War, combats may include wars, where large number of participants can take the field at once, and these may include archers, artillery and fortifications. Sometimes, novelty combat may occur, where for instance, the fighters take the form of chess pieces.\n",
"The Melee mode tosses the players into an arena with any number of the computer-controlled races (but no ships like the players' except those of the players themselves). In Melee, it is \"every man for himself,\" with the computer-controlled races even fighting each other. Alliances and truces can be formed between players, but nothing is binding. Once a player enters the arena, they are there until they die; nothing else returns them to the main menu. Upon dying, if the player still has lives remaining, they may reenter the arena if they wish. Destroying the computer-controlled ships in this mode simply \"spawns\" more ships to fight.\n",
"Melee combat is simultaneous and determined by opposed D6 rolls, modified by the character's Combat value and situational modifiers such as outnumbering or a surprise bonus (called ambush bonus in the rules). Beating an opponent means that he must recoil one base away or fall down; doubling an opponent's score (e.g., an 8 to 4)means that the opponent is killed; and tripling the opponent's score (e.g., a 9 to 3) means that he is gruesomely killed and all friends witnessing his death must make a morale roll.\n",
"\"Melee\" was an arena combat game where each player generated a character by purchasing Strength, Dexterity and equipment as part of a point-based character creation system, and then these characters fought via a tactical combat system that used six-sided dice.\n",
"Melee, or hand-to-hand combat, occurred most often after the tight formation of the phalanx dispersed. This fighting was also often referred to as dorarismos, meaning \"spear-fighting\" because the hoplites would use small swords in the fighting. One example of melee combat is described by Herodotus during a battle at Thermopylae. Herodotus reports that after the Spartans had lost their spears and swords during the dorarismos, they continued fighting \"with their hands and teeth.\"\n",
"The melee combat system consists of using everything as a weapon, most of the items in the game can be used, as some weapons are very effective, but others are comedically inefficient, in addition weapons constantly break forcing the player to constantly use different weapons. \"Dead Rising 2\" introduced a \"Combo Weapons\" system, where the player can combine certain items into more powerful weapons, some of which are over-the-top, such as a lightsaber, made by combining a flashlight with jewelry. \"Dead Rising 3\" enhanced the mechanic by introducing \"Combo Vehicles\" allowing players to combine items with vehicles and even vehicles with other vehicles to make more powerful vehicles, for instance a motorcycle with a chainsaw creates the \"slicecycle\", a motorcycle with two chainsaws at the sides.\n"
] |
What burns during re-entry?
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There is not burning from reentry, but heat to the point where the air becomes ionized and a plasma, and the material is red hot and begins to vaporize.
What is occurring is shock heating, or heat due to change in pressure. It is known that when a gas expands, it cools, and in the same way, when it is compressed it heats up.
On several miles a second projectiles, the pressure will be so extreme that temperatures reach thousands of degrees.
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[
"The most important first action is to stop the burning process. The source of the burn should promptly be removed (or the patient removed from the source). If the person is on fire, he/she must be told to stop, drop and roll, or extinguish the fire by covering them with heavy blanket, wool, coat, or rug. Burning clothing should be removed as should all jewelry that could act as a tourniquet as swelling occurs, but burned clothing stuck to the skin must not be removed. Cooling the burn with cold running water has been shown to be beneficial if accomplished within 30 minutes of the injury. The pain or inflammation can then be effectively treated using acetaminophen (paracetamol), or ibuprofen. Ice, butter, cream and ointment cannot be used since they can worsen the burn.\n",
"Recovery efforts were slowed as crews tested burned debris for environmental contaminants such as asbestos, volatile organic compounds, heavy metals, arsenic, dioxins, and other hazardous materials that may have burned or spread in the fire.\n",
"The emergency services arrived on the scene soon after the blaze started, but were for a long time held back by the force of the flames, which they were only able to contain, not extinguish. The fire did not stop burning for at least a day, and there were fears it might spread to the nearby central petroleum depot at Nsiam, although this was avoided. For days, a column of black smoke hung over the area of the blast.\n",
"Leaving a fire unattended can be dangerous. Any number of accidents might occur in the absence of people, leading to property damage, personal injury or possibly a wildfire. Ash is a good insulator, so embers left overnight only lose a fraction of their heat. It is often possible to restart the new day's fire using the embers.\n",
"Burn-in is the process by which components of a system are exercised prior to being placed in service (and often, prior to the system being completely assembled from those components). This testing process will force certain failures to occur under supervised conditions so an understanding of load capacity of the product can be established.\n",
"BULLET::::7. \"Out of the Ashes\" (Two 1-hour parts) - A previous contractor hired by the homeowners insurance company to repair the home after an electrical fire leaves behind incomplete and substandard work. Mike and crew arrive and, after completely gutting the home, find they must remove asbestos insulation from the basement and do a full toxic-waste remediation caused by leakage from a heating-oil tank left buried in the back yard.\n",
"Clean agents extinguish fire by displacing oxygen (CO or inert gases), removing heat from the combustion zone (Halotron-1, FE-36, Novec 1230) or inhibiting the chemical chain reaction (Halons). They are referred to as clean agents because they do not leave any residue after discharge which is ideal for protecting sensitive electronics, aircraft, armored vehicles and archival storage, museums, and valuable documents.\n"
] |
how are there different "types" of spicy sensations from eating spicy food?
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Because there are different compounds interacting with different receptors.
Peppers have capsaicin, which triggers the same receptors as hot temperature receptors.
Wasabi and mustards have isothiocyanates, a different compound. They are also short lived due to not being oily and volatile, meaning they can easily be washed away, or they evaporate away.
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[
"Gustatory sweating refers to thermal sweating induced by the ingestion of food. The increase in metabolism caused by ingestion raises body temperature, leading to thermal sweating. Hot and spicy foods also leads to mild gustatory sweating in the face, scalp and neck: capsaicin (the compound that makes spicy food taste \"hot\"), binds to receptors in the mouth that detect warmth. The increased stimulation of such receptors induces a thermoregulatory response.\n",
"There is a general belief that eating spicy food and chili pepper in particular heats up passion, but as Jon Bonné says in an article on MSNBC, \"it's a big leap from heat in the mouth to heat between the sheets.\" The penile shape Bonné signals is confirmed by Michael Albertson and Ellen Albertson in their book \"Temptations: Igniting the Pleasure and Power of Aphrodisiacs\": the pepper is what \"he looks like...This very hot Latin lover likes to brag about his size and heat. (What man doesn't?)\" Another name for peter pepper is \"the Chilli Willy peppers\". The uniquely shaped chilis have won a few awards, including the right to be called \"The Most Pornographic Pepper\" by \"Organic Gardening Magazine\".\n",
"Substances such as ethanol and capsaicin cause a burning sensation by inducing a trigeminal nerve reaction together with normal taste reception. The sensation of heat is caused by the food's activating nerves that express TRPV1 and TRPA1 receptors. Some such plant-derived compounds that provide this sensation are capsaicin from chili peppers, piperine from black pepper, gingerol from ginger root and allyl isothiocyanate from horseradish. The piquant (\"hot\" or \"spicy\") sensation provided by such foods and spices plays an important role in a diverse range of cuisines across the world—especially in equatorial and sub-tropical climates, such as Ethiopian, Peruvian, Hungarian, Indian, Korean, Indonesian, Lao, Malaysian, Mexican, New Mexican, Singaporean, Southwest Chinese (including Szechuan cuisine), Vietnamese, and Thai cuisines.\n",
"Although the consumption of spicy food can cause pain, people in many cultures ascribe a high hedonic value to it. Psychologist Paul Rozin puts forth the idea of \"benign masochism\", a learned tendency that overrides the typically aversive stimuli because of the risk-taking or thrill-seeking associated with overcoming pain.\n",
"This particular sensation, called chemesthesis, is not a taste in the technical sense, because the sensation does not arise from taste buds, and a different set of nerve fibers carry it to the brain. Foods like chili peppers activate nerve fibers directly; the sensation interpreted as \"hot\" results from the stimulation of somatosensory (pain/temperature) fibers on the tongue. Many parts of the body with exposed membranes but no taste sensors (such as the nasal cavity, under the fingernails, surface of the eye or a wound) produce a similar sensation of heat when exposed to hotness agents. Asian countries within the sphere of, mainly, Chinese, Indian, and Japanese cultural influence, often wrote of pungency as a fifth or sixth taste.\n",
"A number of vanilloids, most notably capsaicin, bind to the transient receptor potential vanilloid type 1 (TRPV1) receptor, an ion channel which naturally responds to noxious stimuli such as high temperatures and acidic pH. This action is responsible for the burning sensation experienced after eating spicy peppers.\n",
"Flavor is perceived by the combination of the sense of taste, sense of smell, and the trigeminal nerve (CN V). The gustatory system is responsible for differentiation between sweet, sour, salty, bitter, and umami. The olfactory system recognizes the odorants as they pass to the olfactory epithelium via a retronasal pathway. This explains why we can identify a variety of flavors in spite of only having five types of taste receptors. The trigeminal nerve senses texture, pain, and temperature of food. For example, the cooling effect of menthol or the burning sensation of spicy food.\n"
] |
How is it that humans can learn vocal language to virtually perfect speech yet still be illiterate?
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Most of this is because the mapping of symbols on the page to sounds is arbitrary. When speaking you're mapping sounds to meaning. This is something you brain has specifically evolved to handle.
For written text we've invented some arbitrary symbols, we've decided that they map to specific phonemes (or they map in a context dependant manner). Mapping shapes on a page to sounds/words and then mapping that to meaning is something you specifically have to learn. It's an additional skill above and beyond learning to speak a language and you need to learn it. I can speak a number of things in Thai and Korean but I literally have no idea what those things look like on the page nor have any understanding of what sounds their lettering represents.
Alongside this many, many people have dyslexia or related issues with written comprehension which make learning to read non-trivial for them.
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[
"One of the fundamental problems in the study of speech is how to deal with noise. This is shown by the difficulty in recognizing human speech that computer recognition systems have. While they can do well at recognizing speech if trained on a specific speaker's voice and under quiet conditions, these systems often do poorly in more realistic listening situations where humans would understand speech without relative difficulty. To emulate processing patterns that would be held in the brain under normal conditions, prior knowledge is a key neural factor, since a robust learning history may to an extent override the extreme masking effects involved in the complete absence of continuous speech signals.\n",
"Speaking is the default modality for language in all cultures. Humans' first recourse is to encode our thoughts in sound — a method which depends on sophisticated capacities for controlling the lips, tongue and other components of the vocal apparatus.\n",
"Speech synthesis has long been a vital assistive technology tool and its application in this area is significant and widespread. It allows environmental barriers to be removed for people with a wide range of disabilities. The longest application has been in the use of screen readers for people with visual impairment, but text-to-speech systems are now commonly used by people with dyslexia and other reading difficulties as well as by pre-literate children. They are also frequently employed to aid those with severe speech impairment usually through a dedicated voice output communication aid.\n",
"A communication disorder interferes with the ability to produce clearly understandable speech. There can be many different causes, such as nerve degeneration, muscle degeneration, stroke, and vocal cord injury. The modern method to deal with speaking disabilities has been to provide a text interface for a speech synthesizer for complete vocal disability. This can be a great improvement for people that have been limited to the use of a throat vibrator to produce speech since the 1960s.\n",
"Karl Wernicke also used postmortem studies to link specific areas of the brain with speech production. However his research focused more on patients who could speak, however their speech made little sense and/or had trouble understanding spoken words or sentences.\n",
"Specialists theorize that the spoken word can be difficult for some gifted children because they have the added task of translating the complex ideas in their heads into language that others of similar age can understand. This process can lead to abnormal hesitation when speaking, stuttering, and frustration on the part of the child.\n",
"Deaf children do not acquire speech the same as hearing children because they cannot hear the language spoken around them. In normal language acquisition, auditory comprehension precedes the development of language. Without auditory input, a person with prelingual deafness is forced to acquire speech visually through lip-reading. Acquiring spoken language through lip-reading alone is challenging for the deaf child because it does not always accurately represent speech sounds. The likelihood of a deaf child successfully learning to speak is based on a variety of factors including: ability to discriminate between speech sounds, a higher than average non-verbal IQ, and a higher socioeconomic status. Despite being fitted with hearing aids or provided with oral instruction and speech therapy at a young age, prelingually deaf children are unlikely to ever develop perfect speech and speech-reception skills. Some researchers conclude that deaf children taught exclusively through spoken language appear to pass through the same general stages of language acquisition as their hearing peers but without reaching the same ultimate level of proficiency. Spoken language that may develop for prelingually deaf children is severely delayed.\n"
] |
how do furnaces work?
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fire from natural gas (or whatever the gas source is) being pushed through the vents via a blower fan
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[
"An industrial furnace is an equipment used to provide heat for a process or can serve as reactor which provides heats of reaction. Furnace designs vary as to its function, heating duty, type of fuel and method of introducing combustion air.\n",
"The furnace is initially loaded with the material to be fused, which is introduced into the crucible from the charge door. Once the loading is completed, current is sent to the electrodes, which generate an electrical arc between them. The arc produces heat which is transmitted to the material to be melted through thermal radiation heat transfer, which is why the furnace is referred to as an indirect or radiant arc device. During the process, the charge door can be reopened to introduce into the crucible further amounts of scrap and cast iron. When all the material has been melted, it undergoes a first refining before it is poured out from the taphole. \n",
"An industrial furnace or direct fired heater, is an equipment used to provide heat for a process or can serve as reactor which provides heats of reaction. Furnace designs vary as to its function, heating duty, type of fuel and method of introducing combustion air. However, most process furnaces have some common features.\n",
"The puddling furnace is a metalmaking technology used to create wrought iron or steel from the pig iron produced in a blast furnace. The furnace is constructed to pull the hot air over the iron without the fuel coming into direct contact with the iron, a system generally known as a reverberatory furnace or open hearth furnace. The major advantage of this system is keeping the impurities of the fuel separated from the charge.\n",
"Furnaces which are constructed in a pit and extend to floor level or slightly above are called pit furnaces. Workpieces can be suspended from fixtures, held in baskets or placed on bases in the furnace. Pit furnaces are suited to heating long tubes, shafts and rods by holding them in a vertical position. This manner of loading provides minimal distortion.\n",
"The \"casthouse\" at the bottom half of the furnace contains the bustle pipe, water cooled copper tuyeres and the equipment for casting the liquid iron and slag. Once a \"taphole\" is drilled through the refractory clay plug, liquid iron and slag flow down a trough through a \"skimmer\" opening, separating the iron and slag. Modern, larger blast furnaces may have as many as four tapholes and two casthouses. Once the pig iron and slag has been tapped, the taphole is again plugged with refractory clay.\n",
"BULLET::::- A furnace can be used either to provide heat to a building or used to melt substances such as glass or metal for further processing. A blast furnace is a particular type of furnace generally associated with metal smelting (particularly steel manufacture) using refined coke or similar hot-burning substance as a fuel, with air pumped in under pressure to increase the temperature of the fire. A blacksmith uses a temporarily blown furnace, the smith's heart to heat iron to a glowing red to yellow temperature.\n"
] |
Would it be possible for Jupiter and/or Saturn to ignite?
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If you did mean set on fire as in a spark causing the hyrdrogen to ignite, no. Oxygen is required for hydrogen to combust, and the composition of Jupiter as far as we're aware contains only a very small amount oxygen.
Also although not a very scientific approach, considering that it's 4.5billion years old now, if it were possible for it to spontaneously combust it probably would have done by now anyway.
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[
"BULLET::::- In the anime \"Heroic Age\", Jupiter is destroyed when a high-powered energy gun is used to knock the moon Io out of orbit. Io plummets into the atmosphere and ignites it, and intervention by the Silver and Bronze fleets leads to a cataclysmic explosion.\n",
"BULLET::::- \"Heroic Age\" (2007), anime. Jupiter is destroyed when a high-powered energy gun is used to knock Io out of orbit. It plummets into the atmosphere and ignites it, and intervention by the Silver and Bronze fleets leads to a cataclysmic explosion.\n",
"BULLET::::- In the PlayStation RPG Final Fantasy VII, Jupiter is destroyed by a comet during Sephiroth's super nova spell sequence. The comet darts through Jupiter, creating a large hole, and causing the planet to implode.\n",
"The astronomer and author Tom Van Flandern held that Phaeton exploded through some internal mechanism. In his \"Exploded Planet Hypothesis 2000\", he lists possible reasons for its explosion: a runaway nuclear reaction of uranium in its core, a change of state as the planet cooled down creating a density phase change, or through continual absorption of heat in the core from gravitons.\n",
"BULLET::::- Explosion on the Sun – An explosion on the surface of Sun causes a temperature rise on Earth and Venus. The Venusian president is contacted by Dr. Duncan, who has been causing the explosions by firing a freighter of beryllium into the Sun. He threatens to release further charges unless Earth and Venus send weapons and robots to Ganymede. (DVD Disc 4)\n",
"The force of the explosion on Jupiter was thousands of times more powerful than the suspected comet or asteroid that exploded over the Tunguska River Valley in Siberia in June 1908. (This would be approximately 12,500–13,000 Megatons of TNT, over a million times more powerful than the bomb dropped on Hiroshima.)\n",
"At Saturn they find the Sun-tap station on Iapetus and, wary of booby traps, drop an H-bomb on it. At Uranus the Sun-tap station sits on Oberon and again they wipe it out with a bomb. Then they head toward Pluto, figuring that they will hit the Sun-tap station at Neptune on their way home. They soon overtake the half-ruined Plutonian ship, which hits \"Magellan\" with an energy bolt that nearly cripples the ship, but then Burl obliterates the alien completely with an atomic blast.\n"
] |
steam trading cards, gems, mystery cards, etc...
|
**Steam Trading Cards are virtual cards earned by playing games on Steam. Sets of cards can be turned into game badges and tradable Steam community items.**
**Once you’ve collected a set of cards you can craft them into a game badge. Like the current badges, they are tied to your account and are shown on your profile. Unlike the current badges, crafting game badges earns you marketable items like emoticons, profile backgrounds, and coupons.**
**Level up your badge by collecting the set again and earning more items.**
**All badges now have XP which contributes to your Steam Level, a summary of your badge collection. You can view someone’s Steam Level by hovering over their avatar. Leveling up earns you non-tradable items like profile showcases, extra friends list slots, and more.**
|
[
"Steam Trading Cards are a digital commodity issued by Valve Corporation for use on its digital distribution platform, Steam. Steam Trading Cards are a non-physical analogue of conventional trading cards, which are periodically granted to Steam users for playing games, fulfilling tasks, or by random chance. Cards can be \"crafted\" to acquire Steam-centric awards such as emoticons or profile backgrounds, traded to other Steam users, or sold through the Steam Community Market for store credit.\n",
"Like their physical counterparts, Steam Trading Cards are a collectible commodity which are routinely traded, bought, and sold. Supported games each have their own set of trading cards, which typically incorporate game art in their designs. After collecting a full set of trading cards, the user has the option to \"craft\" the cards, permanently removing them from their Steam inventory in exchange for a game-themed emoticon, profile background, profile badge, and an amount of Steam \"XP\". XP can be used to increase a profile's level, which unlocks more profile customization options, increases the friend limit cap, and raises the probability of \"booster pack\" trading card drops.\n",
"Since their introduction in 2013, Steam Trading Card sets have been integrated into over 7,000 games. The developer revenue gained through trading card sales has attracted undesirable attention from \"asset flippers\"; developers who release low-quality games onto Steam solely to profit from their trading cards. In a series of blog posts, Valve condemned this behavior, calling such games \"fake games\", and claimed that trading card farming was responsible for damaging the Steam storefront.\n",
"As Steam Trading Cards afforded developers a means to generate revenue beyond game sales, trading cards soon became one of the driving forces behind \"asset flipping\", the process by which Steam games are cheaply and quickly made, often with store-bought assets and minimal differences between each other, in the hopes of netting profit through trading card sales. In an April 2017 joint conference with game commentators Jim Sterling and John \"TotalBiscuit\" Bain, Valve agreed that a large portion of games on Steam only existed to \"mill\" cards for profit, with Valve labeling these asset flips as \"fake games\". In May 2017, Valve claimed that these \"fake games\" harmed Steam by feeding \"faux data\" into the storefront's algorithm, which resulted in asset flips being granted a disproportionate amount of storefront exposure relative to the number of people actually playing them. To counter this, Valve implemented a \"confidence metric\" system, wherein trading cards can only drop for games which pass a sales threshold.\n",
"Steam Trading Cards are distributed through several methods; if a game has a trading card set, playing that game will periodically grant the player trading cards until a threshold is met. For most games, this threshold is reached once the user has received half the number of cards required for a full set. For free to play games, cards won't drop until the player makes a purchase associated with that game. \"Booster packs\", which contain a random assortment of three cards from a game, will periodically drop for users who have hit the drop threshold.\n",
"In the years prior to the introduction of Steam Trading Cards, Valve implemented multiple features into Steam to facilitate the trading, buying, and selling of virtual goods. Steam Trading was introduced in 2011, which allows users to trade virtual game items between each other. During the 2011 Steam Winter Sale, users could complete objectives in select games to receive virtual \"coal\" which could then be redeemed for prizes, a progenitor to the system that would later be utilized for Steam Trading Cards. The Steam Community Market was introduced in late 2012, which enables Steam users to buy and sell virtual goods with store credit.\n",
"Wizards of the Coast LLC (often referred to as WotC or simply Wizards) is an American publisher of games, primarily based on fantasy and science fiction themes, and formerly an operator of retail stores for games. Originally a basement-run role-playing game publisher, the company popularized the collectible card game genre with \"\" in the mid-1990s, acquired the popular \"Dungeons & Dragons\" role-playing game by purchasing the failing company TSR, and further increased its success by publishing the licensed \"Pokémon Trading Card Game\". The company's corporate headquarters are located in Renton, Washington in the United States.\n"
] |
how is your normal facial expression decided?
|
Genetics, Stressers and muscle memory.
Genes is the first thing, you can't change these this can cause things from your skin, your face shape and where fat wants to reside.
Stressers like age, sun damage and sleep deprivations as well as allergic reactions affect the look of your face beyond genetics.
And muscle memory affects your expression based off of how your face usually is, doing it's best to give them impression the majority of the time. Usually people have a resting face that is mostly expressionless, but it might have a hint of excitement or a hint of disgust for example that gives the impression of a happy person or a "Resting Bitchy Face". It doesn't recessarily mean if you're angry all the time you will get an angry resting face, it just means that facial expressions can overtime affect your resting face.
|
[
"Facial expressions are vital to social communication between humans. They are caused by the movement of muscles that connect to the skin and fascia in the face. These muscles move the skin, creating lines and folds and causing the movement of facial features, such as the mouth and eyebrows. These muscles develop from the second pharyngeal arch in the embryo. The temporalis, masseter, and internal and external pterygoid muscles, which are mainly used for chewing, have a minor effect on expression as well. These muscles develop from the first pharyngeal arch.\n",
"Facial expressions are signals that we make by moving our facial muscles on our face. Facial expressions generally signify an emotional state, and each emotional state and/or state of mind has a specific facial expression, many of which are universally used around the world. Without seeing someone's facial expression, one would not be able to see if the other person is crying, happy, angry, etc. Furthermore, facial expressions enable us to further comprehend what is going on during situations that are very difficult and/or confusing.\n",
"Facial expressions are produced to express a reaction to a situation or event or to evoke a response from another individual or individuals. They are signals of emotion and social intent. People make faces in response to \"direct audience effects\" when they are watching sports, discussing politics, eating or smelling, in pain, and see or hear something humorous. While one may have the same emotional reaction to a particular situation, he or she is more likely to express this emotion via a facial expression if they are in a social situation. Smiles, in particular, are \"evolved signaling displays [that] are the result of selective pressures for conspicuous, stereotyped, and redundant communication\". Smiling is a visual signal that requires eye contact from the recipient to the one smiling and is intended to communicate a feeling of happiness and joy. In an experiment by Alan Fridlund, smiling occurred least when one was watching a video alone, then more often when a person was alone watching the video but believed a friend was performing another task, even more often when that person believed a friend was simultaneously watching the video somewhere else, and most often when one was watching a movie with a friend physically present. This evidence shows that even if someone has the same internal reaction to a stimulus (like a movie), they are more likely to externalize these feelings when surrounded by peers or under the assumption that peers are engaged in the same activity.\n",
"Facial expression is integral when expressing emotions through the body. Combinations of eyes, eyebrow, lips, nose, and cheek movements help form different moods of an individual (example happy, sad, depressed, angry, etc.).\n",
"A facial expression is one or more motions or positions of the muscles beneath the skin of the face. According to one set of controversial theories, these movements convey the emotional state of an individual to observers. Facial expressions are a form of nonverbal communication. They are a primary means of conveying social information between humans, but they also occur in most other mammals and some other animal species. (For a discussion of the controversies on these claims, see Fridlund and Russell & Fernandez Dols.)\n",
"Facial expressions, more than anything, serve as a practical means of communication. With all the various muscles that precisely control mouth, lips, eyes, nose, forehead, and jaw, human faces are estimated to be capable of more than ten thousand different expressions. This versatility makes non-verbals of the face extremely efficient and honest, unless deliberately manipulated. In addition, many of these emotions, including happiness, sadness, anger, fear, surprise, disgust, shame, anguish and interest are universally recognized.\n",
"Facial expression is used in sign languages to convey specific meanings. In American Sign Language (ASL), for instance, raised eyebrows combined with a slightly forward head tilt indicate that what is being signed is a yes/no question. Lowered eyebrows are used for wh-word questions. Facial expression is also used in sign languages to show adverbs and adjectives such as distance or size: an open mouth, squinted eyes, and tilted back head indicate something far while the mouth pulled to one side and the cheek held toward the shoulder indicate something close, and puffed cheeks mean very large. It can also show the manner in which something is done, such as carelessly or routinely. Some of these expressions, also called non-manual signs, are used similarly in different sign languages while others are different from one language to another. For example, the expression used for 'carelessly' in ASL means 'boring or unpleasant' in British Sign Language.\n"
] |
How much of their forces did germany devote to the eastern front in WWI?
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By February 1916 the Germans had c. 50 divisions on the eastern front; by September of that year, the number had risen to c. 70 divisions. When the Treaty of Brest-Litovsk was signed, there were 1.5 million German troops in the East, of which 500 000 were shifted to the Western Front by the spring of 1918, starting already in late 1917.
|
[
"On the Eastern Front the volunteers and conscripts in the \"Ostlegionen\" comprised a fighting force equivalent of 30 German divisions by the end of 1943. By mid-1944 upwards of 600,000 troops of the Eastern Legions/Troops were assembled under the command of General Ernst-August Köstring, stemming mostly from the periphery of the Soviet empire; they consisted of non-Slavic Muslim minorities like the Turkestanis, the Volga Tatars, Northern Caucasians, and Azerbaijanis, as well as Georgians and Armenians. The overall effectiveness of Nazi Germany's military collaborators was described by one German commander as one-fifth good, one-fifth bad, and three-fifths inconsistent.\n",
"During World War II, the army covered the border around Blagoveshchensk and sent reinforcements to the active forces fighting on the Eastern Front. Following the beginning of Operation Barbarossa, the German invasion of the Soviet Union, on 22 June 1941, a directive dated 25 June transferred the 59th Tank and 69th Motorized Divisions by rail to the Eastern Front. On 28 June the 31st SmAD departed for the Eastern Front, and remaining units, including the 3rd Fighter Aviation Regiment, were made directly subordinate to the Air Force (VVS) of the 2nd KA. In August the 95th Mixed Aviation Division was formed in the VVS of the 2nd KA; it became the 95th Fighter Aviation Division (IAD) by 1 September. \n",
"The Red Army provided the largest land force in the Allied victory in the European theatre of World War II, and its invasion of Manchuria assisted the unconditional surrender of Imperial Japan. During operations on the Eastern Front, it accounted for 75–80% of casualties the Wehrmacht and Waffen-SS suffered during the war and ultimately captured the Nazi German capital, Berlin.\n",
"For the operation, the Germans used four armies along with a large portion of their total tank strength on the Eastern Front. On 1 July, the 9th Army of Army Group Centre based in the northern side of the salient contained 335,000 men (223,000 combat soldiers); in the south, the 4th Panzer Army and Army Detachment \"Kempf\", of Army Group South, had 223,907 men (149,271 combat soldiers) and 100,000–108,000 men (66,000 combat soldiers) respectively. The 2nd Army, that held the western side of the salient contained an estimated 110,000. In total, the German forces had a total strength of 777,000–779,000 men, and the three attacking armies contained 438,271 combat soldiers. Army Group South was equipped with more armoured vehicles, infantry and artillery than the 9th Army of Army Group Center. The 4th Panzer Army and Army Detachment \"Kempf\" had 1,377 tanks and assault guns, while the 9th Army possessed 988 tanks and assault guns.\n",
"In 1918, the German Army in the east was the most powerful force in the region. Even more importantly, it was not only undefeated, it was victorious (in contrast to the German Army on the western front). However the commander of the German forces in the east, Max Hoffmann, a chief negotiator in the Treaty of Brest-Litovsk, was facing increasing difficulties. He believed, rightly, that his army was the only stabilising influence over the Eastern Europe. Yet with the disintegration of Austria-Hungary, rise of Bolsheviks in the east and various independent governments between the former frontline and Germany, the former \"Oberkommando-Ostfront\" (or \"Ober-Ost\") occupation zone became a thin line to nowhere, connected only to still-German Prussia. The deteriorating situation in Germany, facing the threat of civil war, eventually forced Hoffman to begin to retreat westwards, to Germany, in December 1918. Demoralized officers and mutinous soldiers abandoned their garrisons \"en masse\" and returned home. Only a limited number of units still retained any combat strength.\n",
"The Germans tried again in 1943 to regain the momentum in the Eastern Front by launching a massive pincer movement at the Kursk salient where 1/6th of all Soviet forces were deployed. The spearheads would be the German 9th Army and the 2nd Panzer Army from the north and the 4th Panzer Army along with Army Detachment Kempf from the south. The Soviets believed the heaviest blow would come from the north and massively reinforced the sector directly opposite 9th Army. By July 1943, the 9th Army had become the largest army ever fielded by the Germans even surpassing the much vaunted 6th Army with 335,000 men along with 600 tanks.\n",
"The Allied forces were now large, despite the Russian exit from the war due to the Treaty of Brest-Litovsk in March 1918. Greece and its army (9 divisions) were fully committed to the Entente, while 6,000 Czech and Slovak former prisoners of war held on the Italian front were re-armed, re-organized, and transferred to the Macedonian front to fight for the Entente. The Bulgarians had also increased their army during 1917, and in total manpower, the two sides were roughly equal battalions vs. battalions, plus ten German battalions). However, as 1918 progressed, it was clear that the Entente had momentum the Central Powers lacked. Russian defeat had yielded no meaningful benefit to the Central Powers. The Ottoman Empire faced progressive loss of Arab lands. In Austria-Hungary, non-German and non-Hungarian parts of the multinational empire grew more openly restive. On the Western Front, intense German spring offensives had not defeated France, while American deployment was increasingly effective. Though Bulgaria and the United States were not at war with each other, German victory over the United States appeared conceptually infeasible. Finally, and most importantly for Bulgaria, almost all of its territorial war aims were already achieved, but as World War I was not merely a third Balkan War, Bulgaria could not quit. Alongside its partners, Bulgaria continued to suffer high casualties and civilian privation, including food shortages, seemingly to achieve the unrealized objectives of its allies. As a constitutional monarchy, Bulgaria depended on the consent of its people to keep fighting, while stress and discontent with the war grew.\n"
] |
hypodermic needle model.
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The magic bullet theory is that for the every person in the world when effected by a specific message will have a specific reaction.
The general concept was that if a person was presented with advertising or propaganda they would react in a specific way as a passive participant in the process, being immediately effected by the information. Or your message is fired like a magic bullet into the person brain.
The theory is generally considered disproved by studies of election results which showed the marketing and propaganda effect different audience and groups differently even though the marketing was the same. People who were subject to propaganda were often not effected by the material and were more effect by the attitude of their social group when choosing who to vote for.
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[
"The hypodermic needle model (known as the hypodermic-syringe model, transmission-belt model, or magic bullet theory) is a model of communication suggesting that an intended message is directly received and wholly accepted by the receiver. The model was originally rooted in 1930s behaviorism and largely considered obsolete for a long time, but big data analytics-based mass customization has led to a modern revival of the basic idea.\n",
"The actual placement of the needle electrode can be difficult and depends on a number of factors, such as specific muscle selection and the size of that muscle. Proper needle EMG placement is very important for accurate representation of the muscle of interest, although EMG is more effective on superficial muscles as it is unable to bypass the action potentials of superficial muscles and detect deeper muscles. Also, the more body fat an individual has, the weaker the EMG signal. When placing the EMG sensor, the ideal location is at the belly of the muscle: the longitudinal midline. The belly of the muscle can also be thought of as in-between the motor point (middle) of the muscle and the tendonus insertion point.\n",
"Needle spacing, or pitch, limited the width of the embroidered design. The spacing between the needles is known as rapport. The unit for measuring spacing was the French inch (1.08 English inch). Standard spacing was known as 4/4 rapport. Machines with 3/4, 4/4, and 6/4 were typical. Theses machines had 342, 228, and 156 needles per row. Wider needle spacing and thus larger designs could be produced by removing some of the needles.This was known as 6/4, 12/4, or 16/4 rapport.\n",
"The phrasing \"hypodermic needle\" is meant to give a mental image of the direct, strategic, and planned infusion of a message into an individual. But as research methodology became more highly developed, it became apparent that the media had selective influences on people.\n",
"Hypodermic needles are normally made from a stainless-steel tube through a process known as tube drawing where the tube is drawn through progressively smaller dies to make the needle. The needles are designed with the same general features, including a barrel, plunger, needle and cap. The end of the needle is bevelled to create a sharp pointed tip, letting the needle easily penetrate the skin.\n",
"Needle aspiration biopsy is done with the rapid stabbing motion of the hand guiding a needle tipped syringe and the rapid sucking motion applied to the syringe. It is a method used to diagnose tumor deep in the skin or lymph nodes under the skin. The cellular aspirate is mounted on a glass slide and immediate diagnosis can be made with proper staining or submitted to a laboratory for final diagnosis. A fine needle aspirate can be done with simply a small bore needle and a small syringe (1 cc) that can generate rapid changes in suction pressure. Fine needle aspirate can be used to distinguish a cystic lesion from a lipoma. Both the surgeon and the pathologist must be familiar with the method of procuring, fixing, and reading of the slide. Many centers have dedicated teams used in the harvest of fine needle aspirate.\n",
"The fourth type of needle is a hybrid needle. It is a straight needle with a point on one end and a flexible strand on the other end with a stopper, such as a large lightweight bead, at the end. This type of needle allows a larger project to be worked at one time than a straight needle, while folding up quickly and more compactly for travel.\n"
] |
[Human Body] Is it possible to feel pain that is not actually there?
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Yes. The simplest example would be phantom limb syndrome. There are no nerves to stimulate in this situation. Phantom limb is considered neuropathic pain, but we still don't quite fully understand the mechanism behind it.
Beyond that there are disorders that can lead to allodynia. This is when you experience pain from normally non-noxious stimuli such as a breeze. It is thought to be due to a central process in the brain. Allodynia is most notably implicated in migraines and fibromylagia.
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[
"Pain is an aversive sensation and feeling associated with actual, or potential, tissue damage. It is widely accepted by a broad spectrum of scientists and philosophers that non-human animals can perceive pain, including pain in amphibians.\n",
"There are two main types of pain that we experience in our bodies: pain caused by damage of body tissue and pain caused by nerve damage. Nociceptive pain serves as a warning or signal for tissue damage and works to preserve the body’s equilibrium and functionality. This pain is signaled by the interworkings of both the peripheral and central nervous systems. Another type of pain, known as neuropathic pain, is caused by a direct problem or disease that affects the nerves in the central nervous system.\n",
"The possibility that non-human animals may be capable of perceiving pain has a long history. Initially, this was based around theoretical and philosophical argument, but more recently has turned to scientific investigation.\n",
"It is postulated that most such beings also feel pain, but this is a projection – empathy. Some philosophers, notably René Descartes, denied it entirely, even for such higher mammals as dogs or primates like monkeys; Descartes considered intelligence a pre-requisite for the feeling of pain.\n",
"Congenital insensitivity to pain (CIP), also known as congenital analgesia, is one or more rare conditions in which a person cannot feel (and has never felt) physical pain. The conditions described here are separate from the HSAN group of disorders, which have more specific signs and cause. Because feeling physical pain is vital for survival, CIP is an extremely dangerous condition. It is common for people with the condition to die in childhood due to injuries or illnesses going unnoticed. Burn injuries are among the more common injuries.\n",
"Nociception (physiological pain) signals nerve-damage or damage to tissue. The three types of pain receptors are cutaneous (skin), somatic (joints and bones), and visceral (body organs). It was previously believed that pain was simply the overloading of pressure receptors, but research in the first half of the 20th century indicated that pain is a distinct phenomenon that intertwines with all of the other senses, including touch. Pain was once considered an entirely subjective experience, but recent studies show that pain is registered in the anterior cingulate gyrus of the brain. The main function of pain is to attract our attention to dangers and motivate us to avoid them. For example, humans avoid touching a sharp needle, or hot object, or extending an arm beyond a safe limit because it is dangerous, and thus hurts. Without pain, people could do many dangerous things without being aware of the dangers.\n",
"Although there are numerous definitions of pain, almost all involve two key components. First, nociception is required. This is the ability to detect noxious stimuli which evoke a reflex response that rapidly moves the entire animal, or the affected part of its body, away from the source of the stimulus. The concept of nociception does not imply any adverse, subjective \"feeling\" – it is a reflex action. An example in humans would be the rapid withdrawal of a finger that has touched something hot – the withdrawal occurs before any sensation of pain is actually experienced.\n"
] |
why do some things need 4 aaa batteries instead of fewer number of a stronger battery? example: why use 4 aaa when one might be able to use 2aa.
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AA are not "stronger" than AAA, they just have more power reserve.
They both put out the same voltage though AA can probably do so at a higher amperage if required.
By arranging the batteries in different combinations of parallel and series you can get different combinations of "power" (voltage) or battery life (mAh).
|
[
"AAA batteries are most often used in small electronic devices, such as TV remote controls, MP3 players and digital cameras. Devices that require the same voltage, but have a higher current draw, are often designed to use larger batteries such as the AA battery type. AA batteries have about three times the capacity of AAA batteries. With the increasing efficiency and miniaturization of modern electronics, many devices that previously were designed for AA batteries (remote controls, cordless computer mice and keyboards, etc.) are being replaced by models that accept AAA battery cells.\n",
"An AAA or triple-A battery is a standard size of dry cell battery commonly used in low-drain portable electronic devices. A zinc–carbon battery in this size is designated by IEC as \"R03\", by ANSI C18.1 as \"24\", by old JIS standard as \"UM 4\", and by other manufacturer and national standard designations that vary depending on the cell chemistry.\n",
"As of 2007, AAA batteries accounted for 24% of alkaline primary battery sales in the United States. In Japan as of 2011, 28% of alkaline primary batteries sold were AAA. In Switzerland as of 2008, AAA batteries totaled 30% of primary battery sales and 32% of secondary battery sales.\n",
"Aqueous Li-ion batteries have been of great interest for military use due to their safety and durability. Unlike the high voltage yet volatile non-aqueous Li-ion batteries, aqueous Li-ion batteries have the potential to serve as a more reliable energy source on the battlefield, because external damage to the battery would not diminish performance or cause it to explode. In addition, they are less heavy than traditional batteries and can be manufactured in different shapes, allowing for lighter gear and more efficient placement.\n",
"AA batteries are common in portable electronic devices. An AA battery is composed of a single electrochemical cell that may be either a primary battery (disposable) or a rechargeable battery. Several different chemistries are used for their construction. The exact terminal voltage, capacity and practical discharge rates depend on cell chemistry; however, devices designed for AA cells will usually only take 1.2-1.5 V unless specified by the manufacturer.\n",
"The GP2X requires 2 AA-sized batteries if not running from an external power supply. Due to the high current drain, standard alkaline batteries will not function for very long in the GP2X; NiMH or lithium batteries are recommended.\n",
"Often, a CR-V3 battery is a single cell based on a non-rechargeable lithium battery chemistry, with a nominal voltage of 3 V (the same as 2 alkaline AA batteries). Because both lithium and lithium-ion chemistries offer higher energy density than NiMH rechargeable batteries or even alkaline batteries, a CR-V3 battery is designed to last much longer than a pair of AA batteries.\n"
] |
Would a black hole really appear as a sphere like in Interstellar?
|
The science advisor for interstellar was Kip Thorne, who just shared the Nobel Prize in Physics for his modelling of the gravitational waveform emitted by two merging black holes. He had the movie studio run a relativistic ray tracing code to generate the images of the black hole (given a small accretion disk in place around it). The simulation was the most detailed of its type ever made, and resulted in the publication of 2 academic papers. It did not include magneto-hydrodynamic modelling of the material in the disc, and left out some effects such as doppler boosting, doppler shifting, and gravitational redshifting, but the Einstein ring around the black hole is entirely a result of the light travel paths around the black hole in accordance with GR.
So yes!
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[
"For non-rotating black holes, the photon sphere is a sphere of radius 3/2 \"r\". There are no stable free fall orbits that exist within or cross the photon sphere. Any free fall orbit that crosses it from the outside spirals into the black hole. Any orbit that crosses it from the inside escapes to infinity or falls back in and spirals into the black hole. No unaccelerated orbit with a semi-major axis less than this distance is possible, but within the photon sphere, a constant acceleration will allow a spacecraft or probe to hover above the event horizon.\n",
"The photon sphere is a spherical boundary of zero thickness in which photons that move on tangents to that sphere would be trapped in a circular orbit about the black hole. For non-rotating black holes, the photon sphere has a radius 1.5 times the Schwarzschild radius. Their orbits would be dynamically unstable, hence any small perturbation, such as a particle of infalling matter, would cause an instability that would grow over time, either setting the photon on an outward trajectory causing it to escape the black hole, or on an inward spiral where it would eventually cross the event horizon.\n",
"BULLET::::- In \"\", a supermassive black hole can be seen in the background of space with Astrophysical jets emitted from its poles as Samus' gunship descends to Planet SR388 indicating that the home world of the Metroids and X Parasites is near enough from the center of its or another galaxy for the black hole to be visible from space. However the exact distance from it is unclear given its supermassive size may make it appear closer than it actually is.\n",
"A surface on which light can orbit a black hole is called a photon sphere. The Kerr solution has infinitely many photon spheres, lying between an inner one and an outer one. In the nonrotating, Schwarzschild solution, with \"a\"=0, the inner and outer photon spheres degenerate, so that there is only one photon sphere at a single radius. The greater the spin of a black hole, the farther from each other the inner and outer photon spheres move. A beam of light traveling in a direction opposite to the spin of the black hole will circularly orbit the hole at the outer photon sphere. A beam of light traveling in the same direction as the black hole's spin will circularly orbit at the inner photon sphere. Orbiting geodesics with some angular momentum perpendicular to the axis of rotation of the black hole will orbit on photon spheres between these two extremes. Because the space-time is rotating, such orbits exhibit a precession, since there is a shift in the formula_28 variable after completing one period in the formula_29 variable.\n",
"Any object whose radius is smaller than its Schwarzschild radius is called a black hole. The surface at the Schwarzschild radius acts as an event horizon in a non-rotating body (a rotating black hole operates slightly differently). Neither light nor particles can escape through this surface from the region inside, hence the name \"black hole\".\n",
"While the basic space-like passage of a static black hole cannot be traversed, the Penrose diagrams for solutions representing rotating and/or electrically charged black holes illustrate these solutions' inner event horizons (lying in the future) and vertically oriented singularities, which open up what is known as a time-like \"wormhole\" allowing passage into future universes. In the case of the rotating hole, there is also a \"negative\" universe entered through a ring-shaped singularity (still portrayed as a line in the diagram) that can be passed through if entering the hole close to its axis of rotation. These features of the solutions are, however, not stable and not believed to be a realistic description of the interior regions of such black holes; the true character of their interiors is still an open question.\n",
"The photon sphere is located farther from the center of a black hole than the event horizon. Within a photon sphere, it is possible to imagine a photon that begins at the back of your head, orbiting the black hole, only then to be intercepted by your eyes, allowing you to see the back of your head.\n"
] |
Would I move in opposite direction in space if I pushed smaller object then me ?
|
Yes. If you give the bowling ball momentum in one direction, you will have the same momentum in the opposite direction. This is the same principle that allows rockets to work: exhaust goes in one direction, rocket goes in the other.
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[
"Since the object's velocity vector is constantly changing direction, the moving object is undergoing acceleration by a centripetal force in the direction of the center of rotation. Without this acceleration, the object would move in a straight line, according to Newton's laws of motion.\n",
"In physics, action at a distance is the concept that an object can be moved, changed, or otherwise affected without being physically touched (as in mechanical contact) by another object. That is, it is the nonlocal interaction of objects that are separated in space.\n",
"BULLET::::- Attackers may move one space forward (from their perspective) toward the citadel, or one space left or right on the same ring exclusively. The space being moved into must be vacant with the exception of the citadel which can already be occupied by a fellow attacker. Attackers may not move backwards (from their perspective) or away from the citadel.\n",
"The personal space or Kinesphere is the space around us within reaching possibilities of the limbs without changing one's place. We can use a large area around us (Far Reach Kinesphere) when we use big movements, especially with our limbs. Or we can use a small area (Near Reach Kinesphere) when we move only within near reach of ourselves. In between is called Mid Reach Kinesphere.\n",
"BULLET::::- Defenders can move one space forward (from their perspective) which is away from the citadel, or backward (from their perspective) which is towards the citadel, but they may not move into the citadel (this rule may also imply that a defender on the second ring cannot perform a capturing leap over an attacker on the first ring, and land on the citadel). They may also move left or right any number of unoccupied spaces on the same ring, but if moving into a space in the Neutral Zone, the defender must stop and end its turn. This prevents the defender from indefinitely moving around the ring.\n",
"An object moving in a circular motion—such as a satellite orbiting the Earth—is accelerating due to the change of direction of motion, although its speed may be constant. In this case it is said to be undergoing \"centripetal\" (directed towards the center) acceleration.\n",
"BULLET::::- if the velocity is straight outward from the axis, the Coriolis force is against the direction of local rotation. (In the tower example, a ball launched upward would move toward the west.)\n"
] |
Historically speaking, Ukraine wasn't where it is now. It's in what used to belong to Crimea. What's the logic behind Ukraine's placement after the fall of the USSR?
|
I'm no expert so I don't have any answer, but could you clarify what you're talking about a little? If I look at some easy-to-find sources (wikipedia, etc.) on the history of Ukraine, I'm not seeing anything that looks like this:
> Ukraine was in a completely different part of Europe than we think of today (That is to say, more towards central-eastern Europe)
Borders have changed a bit of course, but everything I saw seemed to be situated around the western/central regions of modern Ukraine. Maybe you have a map illustrating what you mean?
This might just be me not finding good sources, of course - I've not spent so long looking, and most searches for "historical Ukraine" and the like are just full of information about historical sites within Ukraine...
|
[
"From 1922 until 1991, \"Ukraine\" (also \"the Ukraine\") was the name of the territory of the Ukrainian Soviet Socialist Republic (Украї́нська Радя́нська Соціалісти́чна Респу́бліка, \"Ukrayins'ka Radyans'ka Sotsialistychna Respublika\") within the Soviet Union (annexed by Germany as Reichskommissariat Ukraine during 1941–1944).\n",
"Crimea was previously under Russian control from 1783 until 1954 (punctuated by short periods during political upheavals and wars), when it was transferred, within the USSR, to the Ukrainian SSR. Later, following a referendum on 20 January 1991, it was upgraded to the status of an autonomous republic within the Ukrainian SSR. When the Soviet Union collapsed in 1991 and Ukraine became an independent country, Crimea remained part of the newly independent Ukraine.\n",
"After the dissolution of the Soviet Union in 1991, Ukraine became its own unitary state, however, also containing regions heavily populated by Russians. This caused a few rebellions throughout the eastern parts of the nation, taking place in the self-declared republics of the Donetsk People's Republic, the Luhansk People's Republic, and the peninsula of Crimea. Crimea is disputed by both Ukraine and the Russian Federation. Many nations oppose Russia's annexation of Crimea.\n",
"The territory of modern Ukraine has been inhabited since 32,000 BC. During the Middle Ages, the area was a key centre of East Slavic culture, with the powerful state of Kievan Rus' forming the basis of Ukrainian identity. Following its fragmentation in the 13th century, the territory was contested, ruled and divided by a variety of powers, including Lithuania, Poland, Austria-Hungary, the Ottoman Empire and Russia. A Cossack republic emerged and prospered during the 17th and 18th centuries, but its territory was eventually split between Poland and the Russian Empire, and finally merged fully into the Russian-dominated Soviet Union in the late 1940s as the Ukrainian Soviet Socialist Republic. In 1991, Ukraine gained its independence from the Soviet Union in the aftermath of its dissolution at the end of the Cold War. Before its independence, Ukraine was typically referred to in English as \"The Ukraine\", but most sources have since moved to drop \"the\" from the name of Ukraine in all uses.\n",
"The Ukrainian SSR was a founding member of the United Nations, although it was legally represented by the All-Union state in its affairs with countries outside of the Soviet Union. Upon the Soviet Union's dissolution and \"perestroika\", the Ukrainian SSR was transformed into the modern nation-state and renamed itself to Ukraine.\n",
"Beginning in the late 18th century most of Ukraine was first part of the Russian Empire. Afterwards, Western Ukraine was part of the Austro-Hungarian Empire and then passed to the Second Polish Republic until the 1939 Soviet invasion of Poland. Ukraine then joined the Soviet Union (both the Russian SSR and the Ukrainian SSR united into the Soviet Union from 1922) until Ukraine declared independence from the Soviet Union on 24 August 1991. Independent Ukraine originally maintained strong ties with Russia, and as such Ukraine's economy became integrated with the Russian economy.\n",
"The idea of Ukraine as borderland crept into the English language at some point. Therefore, while Ukraine was part of the Soviet Union, Anglophones referred to the Ukrainian SSR as \"The Ukraine\". However, since the fall of the Soviet Union, the officially recognized name is simply \"Ukraine\". The definite article may imply that it is a land or general geographic area with unidentified borders.\n"
] |
how do cameras focus, and why does the background get blurry?
|
This will work better if you're nearsighted, but should work even if you're not. Look at something in the distance that's blurry because it's far away. Now squint--see how, for a little moment, it's easier to see because you're squinting? Cameras essentially focus by 'squinting' -- adjusting the lens so that the focus is on something different.
|
[
"Photographs taken with this technique are characterized by blurred streaks emanating from the center of the photograph. The effect is nearly identical to a motion blur image in which the camera is traveling towards the subject. For this reason the zoom burst is typically used to create an impression of motion towards the subject.\n",
"Because the effect is caused by the relative motion between the camera, and the objects and scene, motion blur may be avoided by panning the camera to track those moving objects. In this case, even with long exposure times, the objects will appear sharper, and the background more blurred.\n",
"During a scanning cycle, the picture doesn’t follow the input signal. This does not allow the eye to refresh and can lead to blurring during motion sequences, also the transition is visible between frames because the backlight is constantly illuminated, adding to display motion blur.\n",
"A special case occurs when the camera is moved during exposure while keeping it pointed at a moving target, so as to hold its projection on the recording medium steady. The stationary environment (usually mainly background, but possibly also some foreground) then is subjected to ICM and appears streaked in the final image.\n",
"Camcorders use accelerometers for image stabilization, either by moving optical elements to adjust the light path to the sensor to cancel out unintended motions or digitally shifting the image to smooth out detected motion. Some stills cameras use accelerometers for anti-blur capturing. The camera holds off capturing the image when the camera is moving. When the camera is still (if only for a millisecond, as could be the case for vibration), the image is captured. An example of the application of this technology is the Glogger VS2, a phone application which runs on Symbian based phones with accelerometers such as the Nokia N96. Some digital cameras contain accelerometers to determine the orientation of the photo being taken and also for rotating the current picture when viewing.\n",
"Long lenses also make it easier to blur the background more, even when the depth of field is the same; photographers will sometimes use this effect to defocus the background in an image to \"separate\" it from the subject. This background blurring is often referred to as bokeh by photographers.\n",
"Motion blur is caused when either the camera or the subject moves during the exposure. This causes a distinctive streaky appearance to the moving object or the entire picture (in the case of camera shake).\n"
] |
why does the human body become dependant on drugs that are not natural to it?
|
It depends a lot on the drug as to what's happening in the body, but two general reactions is that the drug either induces a standard process in the body, or replaces a hormone in the body. In either case, the body learns to stop inducing or producing whatever process the drug supplements because it saves the body energy (which is the body's ultimate goal).
When someone stops taking the drug, the body freaks out because it's suddenly missing a critical process. The withdrawal symptoms are the body reacting to this missing process and attempting to get things started again.
People can die because some processes are necessary for life and the body dies without it or without proper care when it stops.
|
[
"Drugs (especially opioids and stimulants) can change the motivational patterns of a person and lead to desocialization and degradation of personality. Acquisition of the drugs some times involves black market activities and leads to criminal social circle.\n",
"Why do humans seek out and at times even develop addictions to drugs that harm them? A number of attempts have been made to understand drug use and addiction from an evolutionary perspective. Evolutionary models of drug use are unique in that they emphasize the effect drugs had on fitness over human evolution.\n",
"Researchers suggest that because variation in drug use susceptibility is in part due to genetic factors, drug consumption could potentially be a costly and honest signal of biological quality. The hypothesis being that humans engage in substance use despite health costs in part to evidence that they can afford to do so. To test the effects substance use had on indicators of mating success researchers tested the effect an individual's fluctuating asymmetry had on the propensity/likelihood to use drugs and found no significant results.\n",
"The idea that the effect of a drug in the human body is mediated by specific interactions of the drug molecule with biological macromolecules, (proteins or nucleic acids in most cases) led scientists to the conclusion that individual chemicals are required for the biological activity of the drug. This made for the beginning of the modern era in pharmacology, as pure chemicals, instead of crude extracts of medicinal plants, became the standard drugs. Examples of drug compounds isolated from crude preparations are morphine, the active agent in opium, and digoxin, a heart stimulant originating from Digitalis lanata. Organic chemistry also led to the synthesis of many of the natural products isolated from biological sources.\n",
"An example is often portrayed in drug addiction. When a person uses a substance for the first time and receives a positive outcome, they are likely to repeat the behavior due to the reinforcing consequence. Over time, the person's nervous system will also develop a tolerance to the drug. Thus only by increasing dosage of the drug will provide the same satisfaction, making it dangerous for the user.\n",
"The action of drugs on the human body is called pharmacodynamics, and what the body does with the drug is called pharmacokinetics. The drugs that enter the human tend to stimulate certain receptors, ion channels, act on enzymes or transporter proteins. As a result, they cause the human body to react in a specific way.\n",
"In \"Drugs in American Society\", Goode argued that the effect of a drug is dependent on the societal context in which it is taken. Thus, in one society (or social context) a particular drug may be a depressant, and in another it may be a stimulant.\n"
] |
The Eagle Nebula - what would it currently look like?
|
Unless this is *very* recent news (i.e., the last day or so), then I don't think it's true. There hasn't been a supernova in the Milky Way for some time -- [they average at just a couple per century](_URL_0_) -- which is an interesting problem in itself.
You should be fine using the HST image.
|
[
"The Eagle Nebula (catalogued as Messier 16 or M16, and as NGC 6611, and also known as the Star Queen Nebula and The Spire) is a young open cluster of stars in the constellation Serpens, discovered by Jean-Philippe de Chéseaux in 1745–46. Both the \"Eagle\" and the \"Star Queen\" refer to visual impressions of the dark silhouette near the center of the nebula, an area made famous as the \"Pillars of Creation\" imaged by the Hubble Space Telescope. The nebula contains several active star-forming gas and dust regions, including the aforementioned Pillars of Creation.\n",
"The Eagle Nebula is part of a diffuse emission nebula, or H II region, which is catalogued as IC 4703. This region of active current star formation is about 7000 light-years distant. A spire of gas that can be seen coming off the nebula in the northeastern part is approximately 9.5 light-years or about 90 trillion kilometers long.\n",
"The nebula is approximately 8,000 years old. It is approximately circular in cross-section with a little visible internal structure. It was formed from the outflow of material from the stellar wind of the central star as it evolved along the asymptotic giant branch. The nebula is arranged in three concentric shells, with the outermost shell being about 20–30% larger than the inner shell. The owl-like appearance of the nebula is the result of an inner shell that is not circularly symmetric, but instead forms a barrel-like structure aligned at an angle of 45° to the line of sight.\n",
"The Owl Nebula (also known as Messier 97, M97 or NGC 3587) is a planetary nebula located approximately 2,030 light years away in the constellation Ursa Major. It was discovered by French astronomer Pierre Méchain on February 16, 1781. When William Parsons, 3rd Earl of Rosse, observed the nebula in 1848, his hand-drawn illustration resembled an owl's head. It has been known as the Owl Nebula ever since.\n",
"The Southern Crab Nebula or Hen 2-104 is a nebula in the constellation Centaurus. The nebula is several thousand light years from Earth, and its central star is a symbiotic Mira variable - white dwarf pair. It is named for its resemblance to the Crab Nebula, which is in the northern sky.\n",
"South of the Eagle Nebula on the border with Sagittarius is the eclipsing binary W Serpentis, whose primary is a white giant that is interacting with the secondary. The system has been found to contain an accretion disk, and was one of the first discovered Serpentids, which are eclipsing binaries containing exceptionally strong far-ultraviolet spectral lines. It is suspected that such Serpentids are in an earlier evolutionary phase, and will evolve first into double periodic variables and then classical Algol variables. Also near the Eagle Nebula is the eclipsing Wolf–Rayet binary CV Serpentis, consisting of a Wolf–Rayet star and a hot O-type subgiant. The system is surrounded by a ring-shaped nebula, likely formed during the Wolf–Rayet phase of the primary. The eclipses of the system vary erratically, and although there are two theories as to why, neither of them is completely consistent with current understanding of stars.\n",
"The Saturn Nebula or NGC 7009 is a planetary nebula in the constellation Aquarius. It appears as a greenish-yellowish hue in a small amateur telescope. It was discovered by William Herschel on September 7, 1782, using a telescope of his own design in the garden at his home in Datchet, England, and was one of his earliest discoveries in his sky survey. The nebula was originally a low-mass star that ejected its layers into space, forming the nebula. The central star is now a bright white dwarf star of apparent magnitude 11.5. The Saturn Nebula gets its name from its superficial resemblance to the planet Saturn with its rings nearly edge-on to the observer. It was so named by Lord Rosse in the 1840s, when telescopes had improved to the point that its Saturn-like shape could be discerned. William Henry Smyth said that the Saturn Nebula is one of Struve's nine \"Rare Celestial Objects.\"\n"
] |
why is southern europe relatively lush compared to the deserts of north africa when they are both next to the mediterranean?
|
Okay, so the comments so far only are only partially correct but the main reason is persistent high pressure which results in subsidence. There is a concept referred to as a [Hadley cell](_URL_0_) which is a basic description of how the atmosphere circulates. Essentially, the equator is hot and the poles are cold. Hot air rises and cold air sinks because cold air is more dense. To generalize, air from the equator moves toward the poles and air at the poles moves toward the equator. But it's not that simple since we are dealing with three dimensions as well as the Coriolis effect (sometimes incorrectly referred to as the Coriolis force) not to mention a variation in topography and surface cover (water vs bare land vs heavy vegetation). In any case, as you can see in the image, the Hadley cells near the equator depict air rising at the equator, moving poleward, and then decending at around 30ish degrees latitude. This descending air is key because as air descends, it heats up due to compression (more air pressure at the surface than aloft). The warmer air gets, the more water vapor it can carry. Now, there is such a thing called relative humidity...which is basically how much water vapor a body of air is holding vs. how much it could hold before producing precipitation. Since the water vapor content of the descending air does not change (because air of different temperatures and humidity tends not to mix very easily), the relative humidity goes down. To put it another way, say the air is 50 degrees F and has 100 units of water vapor, and it can hold 1000 units of water vapor at that temperature. In this case, there would be 10% relative humidity. Now, when that air sinks, it might heat up to say, 100 degrees F and since it is warmer, it can hold more water vapor (say, 10,000 units) so the RH would be 1%. Of course those numbers are completely fictional, but it illustrates the concept.
TL;DR...air is generally descending over the sahara due to persistent high pressure. Descending air heats up adiabatically and causes RH to drop. Therefore, there is a major deficit of precipitation year round.
|
[
"In Europe, some Mediterranean areas have a steppe-like vegetation, such as central Sicily in Italy, southern Portugal, parts of Greece in the southern Athens area, and central-eastern Spain, especially the southeastern coast (around Murcia), and places cut off from adequate moisture due to rain shadow effects such as Zaragoza.\n",
"The climate of Africa is a range of climates such as the equatorial climate, the tropical wet and dry climate, the tropical monsoon climate, the semi-desert climate (semi-arid), the desert climate (hyper-arid and arid), and the subtropical highland climate. Temperate climates are rare across the continent except at very high elevations and along the fringes. In fact, the climate of Africa is more variable by rainfall amount than by temperatures, which are consistently high. African deserts are the sunniest and the driest parts of the continent, owing to the prevailing presence of the subtropical ridge with subsiding, hot, dry air masses. Africa holds many heat-related records: the continent has the hottest extended region year-round, the areas with the hottest summer climate, the highest sunshine duration, and more.\n",
"The northern half of Africa is occupied by the world's most extensive hot, dry region, the Sahara Desert. Some deserts are also occupying much of southern Africa : the Namib and the Kalahari. Across Asia, a large annual rainfall minimum, composed primarily of deserts, stretches from the Gobi Desert in Mongolia west-southwest through western Pakistan (Balochistan) and Iran into the Arabian Desert in Saudi Arabia. Most of Australia is semi-arid or desert, making it the world's driest inhabited continent. In South America, the Andes mountain range blocks Pacific moisture that arrives in that continent, resulting in a desertlike climate just downwind across western Argentina. The drier areas of the United States are regions where the Sonoran Desert overspreads the Desert Southwest, the Great Basin and central Wyoming.\n",
"The northern portion of the Maghreb region of northwestern Africa has a Mediterranean climate, separated from the Sahara Desert, which extends across North Africa, by the Atlas Mountains. In the eastern Mediterranean the Sahara extends to the southern shore of the Mediterranean, with the exception of the northern fringe of the peninsula of Cyrenaica in Libya, which has a dry Mediterranean climate.\n",
"Southern Europe's most emblematic climate is that of the Mediterranean climate, which has become a typically known characteristic of the area, which is due to the large subtropical semi-permanent centre of high atmospheric pressure found, not in the Mediterranean itself, but in the Atlantic Ocean, the Azores High. The Mediterranean climate covers Portugal, Southern and Eastern Spain, Southern France, Monaco, Italy, Greece, coastal Croatia, Albania, as well as the Mediterranean islands. Those areas of Mediterranean climate present similar vegetations and landscapes throughout, including dry hills, small plains, pine forests and olive trees.\n",
"The main natural vegetation cover in Europe is mixed forest. The conditions for growth are very favourable. In the north, the Gulf Stream and North Atlantic Drift warm the continent. Southern Europe could be described as having a warm, but mild climate. There are frequent summer droughts in this region. Mountain ridges also affect the conditions. Some of these (Alps, Pyrenees) are oriented east-west and allow the wind to carry large masses of water from the ocean in the interior. Others are oriented south-north (Scandinavian Mountains, Dinarides, Carpathians, Apennines) and because the rain falls primarily on the side of mountains that is oriented towards the sea, forests grow well on this side, while on the other side, the conditions are much less favourable. Few corners of mainland Europe have not been grazed by livestock at some point in time, and the cutting down of the pre-agricultural forest habitat caused disruption to the original plant and animal ecosystems.\n",
"North Africa and Southern Europe face each other across the Mediterranean Sea. Most of the southern areas of North Africa are cut off by the vast inhospitable Sahara desert. Therefore, the coastal areas have many resources to support the needs of large armies and the moderate-to-hot climate makes the movement of forces across vast stretches of land very feasible. North Africa has been the source of both cultural and economic interactions as well as military rivalries that became famous wars in history.\n"
] |
I've heard that the Ancient Romans saw large penises as a sign of barbarism. To what extent is this the case?
|
In general, the surviving sculptures, vases, and writings describing male beauty in the Greco-Roman world depict the ideal of beauty for men (especially young men) as being hairless, thin, athletic, and with a small penis with a tapering foreskin. Large penises are most often found on satyrs, ugly old men, and barbarians, which suggests that they were viewed as grotesque, comical, and outlandish. In his study *Greek Homosexuality*, Kenneth Dover writes:
> In caricature and in the representation of satyrs a penis of great
size, even of preposterous size, is very common, and it is a reasonable
conclusion (though not, I admit, an inescapable conclusion) that if a
big penis goes with a hideous face, and a small penis with a handsome
face, it is the small penis which was admired.
As for why this would be the case, we can only speculate, but *Greek Homosexuality* does a good job of arguing why and how Greco-Roman conceptions of sexuality were not the same as modern conceptions of sexual orientation. Sexuality was considered more fluid, especially in the case of sexual relationships between older men and adolescent boys, which were not seen to make either of the participants exclusively homosexual. Therefore a standard of male beauty evolved around what these older men desired in younger men, which tended to be a slim, hairless, somewhat feminine physique with a small penis, rather than a more virile or well-endowed standard based around, for example, female sexual pleasure or desire. It was the older men who largely ran Greek and Roman society, and who created and patronized most of the art and literature, so it is their concept of male beauty which we know about.
A PDF of *Greek Homosexuality* is [here](_URL_0_). I pulled that quote from page 126.
EDIT: I realize this answer is mostly about the Greeks when OP asked about the Romans, but from what I've heard the Romans had similar views on penis size as the Greeks, and *Greek Homosexuality* was the best academic source I could find about ancient Mediterranean dick size preferences.
|
[
"Nonetheless, there are indications that the Greeks had an open mind about large penises. A statue of the god Hermes with an exaggerated penis stood outside the main gate of Athens and in Alexandria in 275 BC, a procession in honor of Dionysus hauled a 180-foot phallus through the city and people venerated it by singing hymns and reciting poems. The Romans, in contrast to the Greeks, seem to have admired large penises and large numbers of large phalli have been recovered from the ruins of Pompeii. Depictions of Priapus were very popular in Roman erotic art and literature. Over eighty obscene poems dedicated to him have survived.\n",
"Perceptions of penis size are culture-specific. Some prehistoric sculptures and petroglyphs depict male figures with exaggerated erect penises. Ancient Egyptian cultural and artistic conventions generally prevented large penises from being shown in art, as they were considered obscene, but the scruffy, balding male figures in the Turin Erotic Papyrus are shown with exaggeratedly large genitals. The Egyptian god Geb is sometimes shown with a massive erect penis and the god Min is almost always shown with an erection.\n",
"The ancient Greeks believed that small penises were ideal. Scholars believe that most ancient Greeks probably had roughly the same size penises as most other Europeans, but Greek artistic portrayals of handsome youths show them with inordinately small, uncircumcised penises with disproportionately large foreskins, indicating that these were seen as ideal. Large penises in Greek art are reserved exclusively for comically grotesque figures, such as satyrs, a class of hideous, horse-like woodland spirits, who are shown in Greek art with absurdly massive penises. Actors portraying male characters in ancient Greek comedy wore enormous, fake, red penises, which dangled underneath their costumes; these were intended as ridiculous and were meant to be laughed at.\n",
"In addition to repeatedly described anal intercourse, oral sex was common. A graffito from Pompeii is unambiguous: \"Secundus is a fellator of rare ability\" (\"Secundus felator rarus\"). In contrast to ancient Greece, a large penis was a major element in attractiveness. Petronius describes a man with a large penis in a public bathroom. Several emperors are reported in a negative light for surrounding themselves with men with large sexual organs.\n",
"Various perceptions of the vagina have existed throughout history, including the belief it is the center of sexual desire, a metaphor for life via birth, inferior to the penis, unappealing to sight or smell, or vulgar. These views can largely be attributed to sex differences, and how they are interpreted. David Buss, an evolutionary psychologist, stated that because a penis is significantly larger than a clitoris and is readily visible while the vagina is not, and males urinate through the penis, boys are taught from childhood to touch their penises while girls are often taught that they should not touch their own genitalia, which implies that there is harm in doing so. Buss attributed this as the reason many women are not as familiar with their genitalia, and that researchers assume these sex differences explain why boys learn to masturbate before girls and do so more often.\n",
"According to Hodges, ancient Greek aesthetics of the human form considered circumcision a mutilation of a previously perfectly shaped organ. Greek artwork of the period portrayed penises as covered by the foreskin (sometimes in exquisite detail), except in the portrayal of satyrs, lechers, and barbarians. This dislike of the appearance of the circumcised penis led to a decline in the incidence of circumcision among many peoples that had previously practiced it throughout Hellenistic times.\n",
"It is likely that the cases he described were actually hypospadias, a condition in which the urinary meatus is on the underside of the penis. Neither condition has been shown to have a higher frequency in Jews or Muslims.\n"
] |
why does my dog smell differently when he comes inside from the cold?
|
The air oxidizes the oils in his fur, changing the way it smells to us. It happens to people too. Try smelling yourself before and after you spend some time in a windy area.
|
[
"Dogs, as with all mammals, have natural odors. Natural dog odor can be unpleasant to dog owners especially when dogs are kept inside the home, as some people are not used to being exposed to the natural odor of a non-human species living in proximity to them. Dogs may also develop unnatural odors as a result of skin disease or other disorders or may become contaminated with odors from other sources in their environment.\n",
"The dog jumps back into the icy water and after he returns frozen in a block of ice and thaws himself out in the fireplace, his cold returns. Pepé tries to get rid of him again with his smell, but fails. The dog then goes over to get a bottle of perfume and sprays it over himself and Pepé. Unable to stand the smell of perfume, Pepé runs off outside, jumps into the icy water and returns to thaw himself out in the fireplace, at which point he catches a cold himself. The pair finally agree to live with the colds and each other since neither can get rid of the other, and as they sneeze, they both say \"Gesundheit!\".\n",
"The American Kennel Club (AKC) breed standard for the Vizsla states that the coat should be short, smooth, dense, and close-lying, without a woolly undercoat. The Vizsla is totally unsuited to being kept outside since, unlike most other breeds, it does not have an undercoat. They are self-cleaning dogs and infrequently need to be bathed, if ever, and have little noticeable \"dog smell\" detectable by humans. After several forays into lakes and streams they will develop an aroma that is a weaker version of the 'wet dog' smell. A quick bath and this odor will vanish.\n",
"Skunks and dogs often have aggressive encounters and a dog may be sprayed by a skunk. This results in an over-powering musky acrid odor that remains apparent in the 'skunked' dog's coat for many days or even weeks until steps are taken to neutralize the odor.\n",
"The wet nose of dogs is useful for the perception of direction. The sensitive cold receptors in the skin detect the place where the nose is cooled the most and this is the direction a particular smell that the animal just picked up comes from.\n",
"Pepé tries in vain to make the dog go away with his stench. However, thanks to his cold, the dog can't smell a thing. After being forced out, Pepé throws the dog a note which reads: WARNING! A COLD CAN BE FATAL! SEE YOUR DOCTOR NOW! The dog hurriedly phones a Dr. Gesundheit, and Pepé promptly appears in disguise as the doctor. He tries putting a mustard plaster on the dog's nose and ripping it off, which doesn't work. Pepé next tries a steam machine, which after several tries, works, ridding the dog of his cold. Pepé now successfully gets rid of his unwanted guest with his stench.\n",
"A dog's fur depends on its use. Freight dogs should have dense, warm coats to hold heat in, and sprint dogs have short coats that let heat out. Most sled dogs have a double coat, with the outer coat keeping snow away from the body, and a waterproof inner coat for insulation. In warm weather, dogs may have problems regulating their body temperature and may overheat. Their tails serve to protect their nose and feet from freezing when the dog is curled up to sleep. They also have a unique arrangement of blood vessels in their legs to help protect against frostbite.\n"
] |
What causes black holes to have an upper limit to their rotational speed?
|
The *intuitive* reason is that angular momentum has an associated rotational energy. This energy increases the mass of the black hole (through E = Mc^(2)).
Now, if you fix the total mass M, increasing the spin J then increases the fraction of M that is due to this rotational energy, and decreases the fraction of "normal", or "bare" mass (mass it would have if not rotating).
At a certain point, the bare mass becomes zero and M is entirely due to the rotation. This is an extremal Kerr hole. If you continue increasing J then the bare mass must become negative, which means the BH has become superextremal. Superextremal BHs are unstable and are impossible to create. Intuitively because negative mass is impossible.
Thus, for any given total mass, there is an upper bound on the spin which is given by the extremal black hole. Normal black holes satisfying the bound are called subextremal.
|
[
"In this way, rotational energy is extracted from the black hole, resulting in the black hole being spun down to a lower rotational speed. The maximum amount of energy is extracted if the split occurs just outside the event horizon and if particle C is counter-rotating to the greatest extent possible.\n",
"A rotating black hole can produce large amounts of energy at the expense of its rotational energy. This happens through the Penrose process in the black hole's ergosphere, an area just outside its event horizon. In that case a rotating black hole gradually reduces to a Schwarzschild black hole, the minimum configuration from which no further energy can be extracted, although the Kerr black hole's rotation velocity will never quite reach zero.\n",
"Rotating black holes are surrounded by a region of spacetime in which it is impossible to stand still, called the ergosphere. This is the result of a process known as frame-dragging; general relativity predicts that any rotating mass will tend to slightly \"drag\" along the spacetime immediately surrounding it. Any object near the rotating mass will tend to start moving in the direction of rotation. For a rotating black hole, this effect is so strong near the event horizon that an object would have to move faster than the speed of light in the opposite direction to just stand still.\n",
"Qualitatively, frame-dragging can be viewed as the gravitational analog of electromagnetic induction. An \"ice skater\", in orbit over the equator and rotationally at rest with respect to the stars, extends her arms. The arm extended toward the black hole will be torqued spinward. The arm extended away from the black hole will be torqued anti-spinward. She will therefore be rotationally sped up, in a counter-rotating sense to the black hole. This is the opposite of what happens in everyday experience. If she is already rotating at a certain speed when she extends her arms, inertial effects and frame-dragging effects will balance and her spin will not change. Due to the Principle of Equivalence gravitational effects are locally indistinguishable from inertial effects, so this rotation rate, at which when she extends her arms nothing happens, is her local reference for non-rotation. This frame is rotating with respect to the fixed stars and counter-rotating with respect to the black hole. A useful metaphor is a planetary gear system with the black hole being the sun gear, the ice skater being a planetary gear and the outside universe being the ring gear. This can also be interpreted through Mach's principle.\n",
"A rotating black hole has two photon spheres. As a black hole rotates, it drags space with it. The photon sphere that is closer to the black hole is moving in the same direction as the rotation, whereas the photon sphere further away is moving against it. The greater the angular velocity of the rotation of a black hole, the greater the distance between the two photon spheres. Since the black hole has an axis of rotation, this only holds true if approaching the black hole in the direction of the equator. If approaching at a different angle, such as one from the poles of the black hole to the equator, there is only one photon sphere. This is because approaching at this angle the possibility of traveling with or against the rotation does not exist.\n",
"As a black hole rotates, it twists spacetime in the direction of the rotation at a speed that decreases with distance from the event horizon. This process is known as the Lense–Thirring effect or frame-dragging. Because of this dragging effect, an object within the ergosphere cannot appear stationary with respect to an outside observer at a great distance unless that object were to move at faster than the speed of light (an impossibility) with respect to the local spacetime. The speed necessary for such an object to appear stationary decreases at points further out from the event horizon, until at some distance the required speed is that of the speed of light.\n",
"If the complete rotational energy formula_12 of a black hole is extracted, for example with the Penrose process, the remaining mass cannot shrink below the irreducible mass. Therefore, if a black hole rotates with the spin formula_13, its total mass-equivalent formula_1 is higher by a factor of formula_15 in comparison with a corresponding Schwarzschild black hole where formula_1 is equal to formula_17. The reason for this is that in order to get a static body to spin, energy needs to be applied to the system. Because of the mass–energy equivalence this energy also has a mass-equivalent, which adds to the total mass-energy of the system, formula_1.\n"
] |
How did arabic women dress during the abbasid caliphate?
|
The actual cultural dress? No idea. But they were definitely not dressed like belly dancers. The average Muslim woman would have covered the majority of her body other than her face, hands, and feet. Muslim males would have covered the same area except for manual laborers who might have taken their shirt off while working. The actual outfits might have varied from place to place within the Abbassid caliphate but that is what would have been covered by free women in the major cities.
Of course, in distant lands controlled by the Abbassids, you could have any range of dress. I think ibn Battuta mentions in his travels to Africa that he was shocked by how much skin women showed. However, the fact that he was shocked by it shows how rare it would have been in central Abbassid lands.
|
[
"Muslim Turkish-Cypriot women wore traditional Islamic headscarves. When leaving their homes, Muslim Cypriot women would cover their faces by pulling a corner of the headscarf across their nose and mouth, a custom recorded as early as 1769.\n",
"In contrast to the earlier era of the Prophet Muhammad and the Rashidun Caliphate, women in Umayyad and Abbasid society were absent from all arenas of the community's central affairs. While their early Muslim forbearers led men into battle, started rebellions, and played an active role in community life, as demonstrated in the Hadith literature, Abbasid women were ideally kept in seclusion. Conquests had brought enormous wealth and large numbers of slaves to the Muslim elite. The majority of the slaves were women and children, many of whom had been dependents or harem-members of the defeated Sassanian upper classes. In the wake of the conquests an elite man could potentially own a thousand slaves, and ordinary soldiers could have ten people serving them.\n",
"In the specific context of women, the Qur'an at 24:31 speaks of covering women's \"ornaments\" from strangers outside the family. This latter verse of the Qur'an represents the institution of a new public modesty: when the pre-Islamic Arabs went to battle, Arab women seeing the men off to war would bare their breasts to encourage them to fight; or they would do so at the battle itself, as in the case of the Meccan women led by Hind at the Battle of Uḥud. This type of behaviour is commonly seen by Islamic scholars and the broader Muslim public alike as emblematic of a state of spiritual ignorance (\"al-Jāhiliyyah\").\n",
"This partially changed in the Middle Ages after the arrival of the Turkic nomadic tribes from Central Asia, whose women didn't wear headscarves. However, after the Safavid centralization in the 16th century, the headscarf became defined as the standard head dress for women in urban areas all around the Iranian Empire. Exceptions to this were seen only in the villages and among nomadic tribes, such as Qashqai. Covering the whole face was rare among the Iranians and was mostly restricted to local Arabs and local Afghans. Later, during the economic crisis in the late 19th century under the Qajar dynasty, the poorest urban women could not afford headscarves. In the early 20th century, Iranians associated not covering the hair as something rural, nomadic, poor and non-Iranian.\n",
"Many Arab Historians claim that the Pre- and Post-Islamic Arabs of the Hejaz region such as the Quraish, Ansar, Qahtanites, Kindites, Nabateans, Qedarites, Adnanites, Himyarites, Lakhmids, Ghassanids, Arabian Jews and others used to wear the turban, as opposed to the Keffiyeh which is popular today in the Arabian peninsula.\n",
"By the 19th century, upper-class urban Muslim and Christian women in Egypt wore a garment which included a head cover and a \"burqa\" (muslin cloth that covered the lower nose and the mouth). The name of this garment, \"harabah\", derives from early Christian and Judaic religious vocabulary, which may indicate the origins of the garment itself. Up to the first half of the twentieth century, rural women in the Maghreb and Egypt put on a form of \"niqab\" when they visited urban areas, \"as a sign of civilization\".\n",
"Hind bint ‘Utbah was an Arab woman in the late 6th and early 7th centuries who converted to Islam. She took part in the Battle of Yarmouk in 636, fighting the Romans and encouraging the male soldiers to join her.\n"
] |
how can humans survive a partial beheading?
|
If that spinal cord isn’t cut, you won’t die instantly. Granted, you won’t live long with a severed carotid without immediate medical attention (even then it’s a crap shoot).
|
[
"Immurement (from Latin \"im-\" \"in\" and \"murus\" \"wall\"; literally \"walling in\") is a form of imprisonment, usually for life, in which a person is placed within an enclosed space with no exits. This includes instances where people have been enclosed in extremely tight confinement, such as within a coffin. When used as a means of execution, the prisoner is simply left to die from starvation or dehydration. This form of execution is distinct from being buried alive, in which the victim typically dies of asphyxiation.\n",
"BULLET::::- Excarnation is the practice of removing the flesh from the corpse without interment. The Zoroastrians have traditionally left their dead on Towers of Silence, where the flesh of the corpses is left to be devoured by vultures and other carrion-eating birds. Alternatively, it can also mean butchering the corpse by hand to remove the flesh (also referred to as \"defleshing\").\n",
"Whoever is taken prisoner are either used as living incubators in for the Klum's young that inevitably painfully kills the victims, dissected, or forcibly converted into \"human loudspeakers,\" urging humans to surrender into so called \"conservatories\". Very few manage to escape.\n",
"The Mishnah taught that there are 248 parts in a human body, and each one of these parts can render impure by contact, carrying, or being under the same roof when they have upon them flesh sufficient that they could heal if still connected to a living person. But if they do not have sufficient flesh upon them, these individual parts can render impure only by contact and carrying but cannot render impure by being under the same roof (although a mostly intact corpse does).\n",
"Incapacitation is a way to prevent the commission of a crime. An offender punished with death, banishment, imprisonment or mutilation prevents them from being able to repeat an offense permanently or temporarily. Manu urges the king to cut off the offending limb of a thief to prevent them from stealing again. In the case of cutting off a limb it has both a preventative effect and ensures that the same crime will not be committed again.\n",
"Animals or humans may be buried alive accidentally on the mistaken assumption that they are dead, or intentionally as a form of torture, murder, or execution. It may also occur with consent of the victim as a part of a stunt, with the intention to escape.\n",
"Flaying of humans is used as a method of torture or execution, depending on how much of the skin is removed. This is often referred to as \"flaying alive\". There are also records of people flayed after death, generally as a means of debasing the corpse of a prominent enemy or criminal, sometimes related to religious beliefs (e.g. to deny an afterlife); sometimes the skin is used, again for deterrence, esotheric/ritualistic purposes, etc. (e.g. scalping).\n"
] |
What are the differences between a mole and a freckle?
|
Both are types of what are known as *melanocytic lesions* - basically areas with a greater amount of production of melanin than the rest of the skin. Melanin is the pigment that is responsible for difference in skin tone and also the colour of moles and freckles.
Melanin is produced by cells called *melanocytes*. The difference between freckles and moles is as follows:
**In freckles** - no increased number of melanocytes, just an increased amount of melanin
**In moles** - increased number of melanocytes AND an increased amount of melanin
Moles (AKA melanocytic naevi) can arise as either a hamartoma (birth mark) or as a neoplasm (an acquired mole, usually benign [non-cancerous]).
Moles can also be one of three types, depending on their location in the skin:
**Junctional** - flat and brown/black in colour
**Intradermal** - raised. Most are flesh-coloured (i.e. no pigmentation)
**Compound** - slightly raised, brown/black in colour. Think of them as a combination of junctional and intradermal
Hope that helps!
|
[
"Mole-Stache (a play on mole and moustache) is an orange mole-like alien with a British accent and a yellow moustache that can be used in a variety of ways that include serving as an extra set of hands or as a makeshift propeller. While Molestache first appeared in \"Outbreak\" while Blukic and Driba were trying to fix the Omnitrix, Ben got to better utilize the form in \"Breakpoint\" when he defeats Fistrick. \n",
"Freckles are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion. Freckles do not have an increased number of the melanin-producing cells, or melanocytes, but instead have melanocytes that overproduce melanin granules (melanosomes) changing the coloration of the outer skin cells (keratinocytes). As such, freckles are different from lentigines and moles, which are caused by accumulation of melanocytes in a small area.\n",
"The term \"mole\" is especially and most properly used for \"true moles\" of the Talpidae family in the order Eulipotyphla, which are found in most parts of North America, Asia, and Europe, although it may also refer to unrelated mammals of Australia and southern Africa that have convergently evolved the \"mole\" body plan. The term is not applied to all \"talpids\"; e.g., desmans and shrew-moles differ from the common definition of \"mole\".\n",
"While many groups of burrowing animals (pink fairy armadillos, tuco-tucos, mole rats, mole crickets, and mole crabs) have developed close physical similarities with moles due to convergent evolution, two of these are so similar to true moles, they are commonly called and thought of as \"moles\" in common English, although they are completely unrelated to true moles or to each other. These are the golden moles of southern Africa and the marsupial moles of Australia. While difficult to distinguish from each other, they are most easily distinguished from true moles by shovel-like patches on their noses, which they use in tandem with their abbreviated forepaws to swim through sandy soils.\n",
"The trichome is a glandular structure on the ventral surface of the third abdominal segment. It produces a secretion that is attractive to ants and which paralyses them. In addition to this, there are glandular patches on the front few abdominal segments, and these patches, but not the trichome, are also present in nymphs of this species.\n",
"According to the American Academy of Dermatology, the most common types of moles are skin tags, raised moles and flat moles. Benign moles are usually brown, tan, pink or black (especially on dark-colored skin). They are circular or oval and are usually small (commonly between 1–3 mm), though some can be larger than the size of a typical pencil eraser (5 mm). Some moles produce dark, coarse hair. Common mole hair removal procedures include plucking, cosmetic waxing, electrolysis, threading and cauterization.\n",
"This mole grows to a total length of with a tail of about . It is adapted for underground life; the body is cylindrical, the fore-feet are spade-like, the nails are flattened and the eyes are small. The short, dense, dorsal pelage is brownish-grey with a metallic sheen and the underparts are silvery-yellow, with a grey patch on the chest. The bare skin on the muzzle and the feet is yellowish. The short tail is well-covered with hair.\n"
] |
Do any wild organisms have a symbiotic relationship with another to babysit their young?
|
There are functional relationships where one species invests itself in raising the young of another, although the examples I'm familiar with are completely one-sided, which makes them parasitic and not symbiotic. Consider for instance the cuckoo, which will lay its eggs in another birds nest and just ... leave. The other bird cannot tell the difference between its eggs/chicks and the cuckoos, and will raise the cuckoo chick as its own. In return, [the cuckoo chick grows quite fast, is robust, and will kick the hosts chicks out of the nest until it alone remains. Definitely not symbiotic](_URL_5_), but you've got the "species A raising the offspring of species B" side of things.
You suggest the existence of hollow plant nurseries that want fertilizer. Those sort-of exist. There are actually quite a few of those in different unrelated plant lineages such as the south/central american orchid [*Myrmecophila tibicinis*](_URL_2_), southeast asian plants of the genera [*Myrmecodia*](_URL_4_) (these might as well be called pre-fabbed ant nests) and [*Squamellaria*](_URL_3_) as well as [*Acacia cornigera*](_URL_0_) in Africa. Those that I know of are ant-hosting specialists aka ["myrmekophytes"](_URL_1_), and the relationship varies from full grown symbiosis to mutualism. The ants nest inside the plant and patrol the surface, providing protection from parasitic insects and (to some extent) from grazing. Their dejections may also provide nutrients, although the extent to which that matters may vary from one species-couple to the next. The plant provides shelter, and in some cases food through extrafloral nectaries. However, the plant's relationship is with the ant colony as a whole, and not just the young, so it's not quite what you asked for in that respect.
I've also heard of (but have no direct knowledge of) a so-called "babysitting symbiosis" between two species of brittle stars (see: [Fourgon, D., Jangoux, M., & Eeckhaut, I. (2007). Biology of a “babysitting” symbiosis in brittle stars: analysis of the interactions between Ophiomastix venosa and Ophiocoma scolopendrina. Invertebrate Biology, 126(4), 385-395.](_URL_6_)) It doesn't sound as involved as the term "babysitting" would suggest.
|
[
"Most sexually reproducing animals spend their lives as diploid, with the haploid stage reduced to single-cell gametes. The gametes of animals have male and female forms—spermatozoa and egg cells. These gametes combine to form embryos which develop into a new organism.\n",
"Exposed eggs are typically and readily eaten by other pupfish of the same species if not laid in an inconspicuous area, while mobile fry are ignored unless adults are very hungry. Furthermore, though pupfish may engage in filial cannibalism, males have been observed using olfactory cues to distinguish between eggs fertilized by themselves and those fertilized by other males. This has been considered analogous to the defensive behavior of avian victims of nest parasitism, wherein they will reject alien eggs. Similarly, pupfish eggs are typically only consumed by females that do not spawn them; these two factors, coupled with the fact that males show sexual preference towards larger (and therefore more fecund) females, are consistent with parents maximizing the chances of offspring survival.\n",
"At least some species of scolecomorphids give birth to live young, retaining the eggs inside the females' bodies until they hatch into fully formed offspring, without the presence of a free-living larval stage.\n",
"Ovoviviparous animals are similar to viviparous species in which there is internal fertilization and the young ones are born alive, but differ in that there is no placental connection and the unborn young ones are nourished by egg yolk; the mother's body does provide gas exchange (sharks and rays). \n",
"All sexually reproducing life, including both plants and animals, produces gametes. The male gamete cell, sperm, is usually motile whereas the female gamete cell, the ovum, is generally larger and sessile. The male and female gametes combine to produce the zygote cell. In multicellular organisms the zygote subsequently divides in an organised manner into smaller more specialised cells, so that this new individual develops into an embryo. In most animals the embryo is the sessile initial stage of the individual life cycle, and is followed by the emergence (that is, the hatching) of a motile stage. The zygote or the ovum itself or the sessile organic vessel containing the developing embryo may be called the egg.\n",
"Ascidians are almost all hermaphrodites and each has a single ovary and testis, either near the gut or on the body wall. In some solitary species, sperm and eggs are shed into the sea and the larvae are planktonic. In others, especially colonial species, sperm is released into the water and drawn into the atria of other individuals with the incoming water current. Fertilization takes place here and the eggs are brooded through their early developmental stages. Some larval forms appear very much like primitive chordates with a notochord (stiffening rod) and superficially resemble small tadpoles. These swim by undulations of the tail and may have a simple eye, an ocellus, and a balancing organ, a statocyst.\n",
"Fertilisation is similar to that of the Collembola where the male deposits a spermatophore on the ground. This is taken up by a female, who then lays her eggs in clumps in rotting vegetation or in crevices in the soil. Some species are known to guard their eggs and young. Young diplurans resemble adults. Moulting continues throughout life and an adult may moult up to 30 times during its lifespan of about a 1 year. Hapljapyx are predatory carnivores and use their cerci to capture prey.\n"
] |
Can a wave's wavelength be smaller than Planck length? And why?
|
No one knows the answer to this question.
The Planck length just represents the scale at which our current models break down, the scale at which a theory that combines gravity and quantum mechanics will be needed. What the new models that work at that scale will tell us about physics at that scale or smaller is an open question.
|
[
"Whether objects heavier than the Planck mass (about the weight of a large bacterium) have a de Broglie wavelength is theoretically unclear and experimentally unreachable; above the Planck mass a particle's Compton wavelength would be smaller than the Planck length and its own Schwarzschild radius, a scale at which current theories of physics may break down or need to be replaced by more general ones.\n",
"The reciprocal of the Planck time, which is Planck frequency, can be interpreted as an upper bound on the frequency of a wave. This follows from the interpretation of the Planck length as a minimal length, and hence a lower bound on the wavelength.\n",
"A wave consists of successive troughs and crests, and the distance between two adjacent crests or troughs is called the wavelength. Waves of the electromagnetic spectrum vary in size, from very long radio waves the size of buildings to very short gamma rays smaller than atom nuclei. Frequency is inversely proportional to wavelength, according to the equation:\n",
"There is a minimum possible wavelength, given by twice the equilibrium separation \"a\" between atoms. Any wavelength shorter than this can be mapped onto a wavelength longer than 2\"a\", due to the periodicity of the lattice. This can be thought as one consequence of Nyquist–Shannon sampling theorem, the lattice points are viewed as the \"sampling points\" of a continuous wave.\n",
"Louis de Broglie postulated that all particles with a specific value of momentum \"p\" have a wavelength \"λ = h/p\", where \"h\" is Planck's constant. This hypothesis was at the basis of quantum mechanics. Nowadays, this wavelength is called the de Broglie wavelength. For example, the electrons in a CRT display have a De Broglie wavelength of about 10 m. To prevent the wave function for such a particle being spread over all space, de Broglie proposed using wave packets to represent particles that are localized in space. The spatial spread of the wave packet, and the spread of the wavenumbers of sinusoids that make up the packet, correspond to the uncertainties in the particle's position and momentum, the product of which is bounded by Heisenberg uncertainty principle.\n",
"If the obstruction dimensions are much smaller than the wavelength of the incident plane wave, the wave is essentially unaffected. For example, low frequency (LF) broadcasts, also known as long waves, at about 200 kHz has a wavelength of 1500 m and is not significantly affected by most average size buildings, which are much smaller.\n",
"There is a \"minimum possible\" wavelength, given by the equilibrium separation \"a\" between atoms. Any wavelength shorter than this can be mapped onto a wavelength longer than \"a\", due to effects similar to that in aliasing.\n"
] |
if companies like samsung and apple pay (m/b)illions in "patent wars" about violating design patents, how can companies easily create identical iphone or samsung device knockoffs commonly seen on ebay and amazon?
|
They aren't in serious competition, for one; those are entirely different price points.
Also, China.
|
[
"A \"patent war\" between Samsung and Apple started when the latter claimed that the original Galaxy S Android phone copied the interfaceand possibly the hardwareof Apple's iOS for the iPhone 3GS. There was also smartphone patents licensing and litigation involving Sony Mobile, Google, Apple Inc., Samsung, Microsoft, Nokia, Motorola, HTC, Huawei and ZTE, among others. The conflict is part of the wider \"patent wars\" between multinational technology and software corporations. To secure and increase market share, companies granted a patent can sue to prevent competitors from using the methods the patent covers. Since the 2010s the number of lawsuits, counter-suits, and trade complaints based on patents and designs in the market for smartphones, and devices based on smartphone OSes such as Android and iOS, has increased significantly. Initial suits, countersuits, rulings, license agreements, and other major events began in 2009 as the smartphone market stated to grow more rapidly by 2012.\n",
"To secure and increase market share, companies granted a patent can sue to prevent competitors from using the methods the patent covers. Since 2010 the number of lawsuits, counter-suits, and trade complaints based on patents and designs in the market for smartphones, and devices based on smartphone OSes such as Android and iOS, has increased significantly.\n",
"Another study claiming that software patents are of the same importance to small and medium enterprises and large companies, has been described as misleading and as using a flawed methodology, but the results have nevertheless been quoted by politicians.\n",
"Second, the consequence of leaking patents and industrial designs could be devastating. One of the examples is the series of ongoing lawsuits between Apple and Samsung regarding the design of smartphones and tablet computers. \n",
"BULLET::::- There has been a lack of empirical evidence to suggest that patents have any positive effect on innovation, and furthermore, the system primarily “encourage[s] failing monopolists to inhibit competition by blocking innovation.”\n",
"Some have claimed that there are a few oddities with Samsung's U.S. Patent discussed by Hogan during the interview, specifically that the '460 patent has only one claim. Most US patents have between 10 - 20 separate claims, most of which are dependent claims. This patent was filed as a division of an earlier application, possibly in anticipation of litigation, which may explain the reduced number of claims. The specifics of this patent have not been discussed in the Groklaw review or the McKeown review because most believe that the foreman misspoke when he mentioned the number of the patent in question; a more detailed interview with the BBC made it clear that the patent(s) relevant to the prior art controversy were owned by Apple, not Samsung, meaning that his mention of the \"460 patent\" was a mistake.\n",
"The smartphone wars or smartphone patents licensing and litigation refers to commercial struggles among smartphone manufacturers including Sony Mobile, Google, Apple Inc., Samsung, Microsoft, Nokia, Motorola, Huawei, LG Electronics, ZTE and HTC, by patent litigation and other means. The conflict is part of the wider \"patent wars\" between technology and software corporations. The patent wars occurred because a finished smartphone might involve hundreds of thousands of patents.\n"
] |
How would people get phone messages during the 1930's?
|
Not a silly question. There were two types of calls that could be made during this time: person-to-person and station-to-station. If you had a specific person you wanted to talk to you would request a person-to-person call. You wouldn't be billed for the long distance charges until that person came to the phone. This was metered by having the operator on the line with you until the person you wanted came to the phone. Station-to-station calls were made when you didn't really care about who you talked to and one could leave a message with the person who answered if it was intended for a specific person.
Interestingly, person-to-person calls are still available though I don't think anyone uses them anymore. If you look at AT & T's [rates for operator assisted calls](_URL_0_) it shows why one might have hesitated to use this service. The prices were much higher for person-to-person. The upside was you'd likely get billed for fewer minutes.
An interesting note about billing.. the way that billing worked back in the early days of cross country calling was that it was billed in three-minute increments. I have an advertisement from 1927 from a magazine (unfortunately I don't know what magazine as it was just the single page when it was given to me) that says that a call from San Francisco to New York was $9 per billing segment. If you take inflation into account that would be around $120 or $40 per minute today! Clearly you had to be very well to makes calls of this type for personal reasons.
Now regarding privacy, when working with the telegraph and telephone companies at the time there were often a number of people involved in the loop. With telegraphs there was someone on the sending and receiving end who were privy to your communications. With phone calls it was very easy for the operators along the route to listen in, though it wasn't really standard operating practice to do so. The employees of whatever company was employed were of course supposed to keep everything in confidence but you can imagine this wasn't always the case.
That's not to say that privacy wasn't a concern. There's a documented case of a tenant trying to break a lease when they discovered their calls were being listened to. A judge in the 10th District Municipal Court of New York City ruled that it was legal for the lease to be broken. (New York Times, Dec. 1, 1907, p. C12) Relatively early on there were concerns from the financial industry about telephone privacy as well. (See a letter published in the New York Times, Apr. 22, 1916, p. 10) It wasn't really until the advent of Direct Distance Dialing in the 1950s and 1960s that one could feel relatively secure in an operator not listening in on their calls.
|
[
"In the call-box system developed in 1872, a customer would ring the telegraph office for a messenger who would then speed to the customer's door to pick up a handwritten message and return to the telegraph office to have it sent electrically to its destination.\n",
"The Second World War made military use of radio telephony links. Hand-held radio transceivers have been available since the 1940s. Mobile telephones for automobiles became available from some telephone companies in the 1940s. Early devices were bulky, consumed large amounts of power, and the network supported only a few simultaneous conversations. Modern cellular networks allow automatic and pervasive use of mobile phones for voice and data communications.\n",
"Telephones were first set up by Dr. George Fox in the 1880s for quick communication between his home office and a drug store, enabling him to order prescriptions to be delivered by buggy in a moment's notice. Growing to 52 lines in 1894, it increased twofold to 120 by the next year, and surged to 2,346 by 1921 (36 percent of the population at the time).\n",
"The concept dates to the early radio era: a December 1924 BBC 5NG Nottingham phone-in programme is described in a 1925 Radio Times article: \"listeners ... enjoyed the novelty of hearing their own voices taking part\". A prior attempted phone-in to a BBC 2LO London programme \"led to such a rush on the telephones that the Post Office had to intervene\".\n",
"A messenger call has been used in countries in which home telephones are unusual, and before the great boom in cell phones in the early 21st century. A messenger, usually a boy, would go to the recipient’s location to advise him or her to come to a central location at a designated time to receive a phone call.\n",
"Commercialization of the telephone began in 1876, with instruments operated in pairs for private use between two locations. Users who wanted to communicate with persons at multiple locations had as many telephones as necessary for the purpose. Alerting another user of the desire to establish a telephone call was accomplished by whistling loudly into the transmitter until the other party heard the alert. Bells were soon added to stations for signaling, so an attendant no longer needed to wait for the whistle.\n",
"For nearly one hundred years, there were few innovations or advances in telephone services. Voicemail was the result of innovations in telephone products and services made possible by developments in computer technology during the 1970s. These innovations began with the Motorola Pageboy, a simple \"pager\" or \"beeper\" introduced in 1974 that was generally offered in conjunction with answering services that handled busy / no-answer overloads and after hours calls for businesses and professionals. Operators wrote down a caller's message, sent a page alert or \"beep\" and when the party called back, an operator dictated the message.\n"
] |
Why is the weight of a molecule in atomic mass units not exactly equal to the sum of the protons and neutrons?
|
/u/RobusEtCeleritas has a good explanation. It is also important to know that the masses of atoms are measured in amu (atmic mass units), where 1 amu is 1/12 the mass of a carbon 12 atom. This takes into account some of the binding energy that was brought up, but not every atom has the same binding energy per nucleon (protons and neutrons) so essentially no atoms besides carbon 12 will have an integer number mass in amu.
|
[
"The sum of the atomic number \"Z\" and the number of neutrons, \"N\", gives the mass number \"A\" of an atom. Since protons and neutrons have approximately the same mass (and the mass of the electrons is negligible for many purposes) and the mass defect of nucleon binding is always small compared to the nucleon mass, the atomic mass of any atom, when expressed in unified atomic mass units (making a quantity called the \"relative isotopic mass\"), is within 1% of the whole number \"A\".\n",
"Whereas the mass number simply counts the total number of neutrons and protons and is thus a natural (or whole) number, the atomic mass of a single atom is a real number giving the mass of a particular isotope (or \"nuclide\") of the element, expressed in atomic mass units (symbol: u). In general, the mass number of a given nuclide differs in value slightly from its atomic mass, since the mass of each proton and neutron is not exactly 1 u; since the electrons contribute a lesser share to the atomic mass as neutron number exceeds proton number; and (finally) because of the nuclear binding energy. For example, the atomic mass of chlorine-35 to five significant digits is 34.969 u and that of chlorine-37 is 36.966 u. However, the atomic mass in u of each isotope is quite close to its simple mass number (always within 1%). The only isotope whose atomic mass is exactly a natural number is C, which by definition has a mass of exactly 12 because u is defined as 1/12 of the mass of a free neutral carbon-12 atom in the ground state.\n",
"The mass in daltons of an atom is numerically close to the number of nucleons \"A\" in its nucleus. It follows that the molar mass of a compound (grams per mole) is also numerically close to the average number of nucleons per molecule. However, the mass of an atomic-scale object is affected by the binding energy of the nucleons in its atomic nuclei, as well as the mass and binding energy of the electrons. Therefore, this equality holds only for the carbon-12 atom in the stated conditions, and will vary for other substances. For example, the mass of one unbound atom of the common hydrogen isotope (hydrogen-1, protium) is , the mass of one free neutron is , and the mass of one hydrogen-2 (deuterium) atom is . In general, the difference (mass defect) is less than 0.1%; except for hydrogen (about 0.8%), helium-3 (0.5%), lithium (0.25%) and beryllium (0.15%).\n",
"The large majority of an atom's mass comes from the protons and neutrons that make it up. The total number of these particles (called \"nucleons\") in a given atom is called the mass number. It is a positive integer and dimensionless (instead of having dimension of mass), because it expresses a count. An example of use of a mass number is \"carbon-12,\" which has 12 nucleons (six protons and six neutrons).\n",
"For example, the atomic mass unit (1 u) is defined as 1/12 of the mass of a C atom—but the atomic mass of a H atom (which is a proton plus electron) is 1.007825 \"u\", so each nucleon in C has lost, on average, about 0.8% of its mass in the form of binding energy.\n",
"The atomic mass (\"m\") is the mass of an atom. Its unit is the unified atomic mass unit (symbol: u, or Da) where 1 unified atomic mass unit is defined as of the mass of a single carbon-12 atom, at rest. The protons and neutrons of the nucleus account for nearly all of the total mass of atoms, with the electrons and nuclear binding energy making minor contributions. Thus, the atomic mass measured in u has nearly the same value as the mass number.\n",
"The actual mass of an atom at rest is often expressed using the unified atomic mass unit (u), also called dalton (Da). This unit is defined as a twelfth of the mass of a free neutral atom of carbon-12, which is approximately . Hydrogen-1 (the lightest isotope of hydrogen which is also the nuclide with the lowest mass) has an atomic weight of 1.007825 u. The value of this number is called the atomic mass. A given atom has an atomic mass approximately equal (within 1%) to its mass number times the atomic mass unit (for example the mass of a nitrogen-14 is roughly 14 u). However, this number will not be exactly an integer except in the case of carbon-12 (see below). The heaviest stable atom is lead-208, with a mass of .\n"
] |
What race was Attila?
|
Do you mean what race *would* be Attila today? Race as we know it today is an early modern construct that wouldn't have played the same role in his life, akin to saying was he a Christian or a Muslim.
|
[
"Attila (; fl. c. 406–453), frequently called Attila the Hun, was the ruler of the Huns from 434 until his death in March 453. He was also the leader of a tribal empire consisting of Huns, Ostrogoths, and Alans among others, in Central and Eastern Europe.\n",
"Attila grew up in a rapidly changing world. His people were nomads who had only recently arrived in Europe. They crossed the Volga river during the 370s and annexed the territory of the Alans, then attacked the Gothic kingdom between the Carpathian mountains and the Danube. They were a very mobile people, whose mounted archers had acquired a reputation for invincibility, and the Germanic tribes seemed unable to withstand them. Vast populations fleeing the Huns moved from Germania into the Roman Empire in the west and south, and along the banks of the Rhine and Danube. In 376, the Goths crossed the Danube, initially submitting to the Romans but soon rebelling against Emperor Valens, whom they killed in the Battle of Adrianople in 378. Large numbers of Vandals, Alans, Suebi, and Burgundians crossed the Rhine and invaded Roman Gaul on December 31, 406 to escape the Huns. The Roman Empire had been split in half since 395 and was ruled by two distinct governments, one based in Ravenna in the West, and the other in Constantinople in the East. The Roman Emperors, both East and West, were generally from the Theodosian family in Attila's lifetime (despite several power struggles).\n",
"Attila the Hun has had many depictions in popular culture. Many of these depictions either portray him as a great ruler or a ruthless conqueror. Attila has also appeared in numerous German and Norse epics, under the names Etzel and Atli, both with completely different personas. His sudden death remains a fascinating unsolved mystery.\n",
"Kim argues that the war after the death of Attila was actually a rebellion of the western half of the Hunnic empire, led by Ardaric, against the eastern half, led by Ellac as leader of the Akatziri Huns. He further argues that Ardaric, in common with the other leaders of the Gepids, was actually a Hun and not of Germanic origin; he notes that bones from the Gepid period frequently show Asiatic features among the ruling elite. He also notes that Gepid rule in the Carpathian Basin appears to have differed little from that of the Huns. Ardaric's grandson Mundo is identified in sources both as a Hun and as a Gepid. Kim explains the fact that Ardaric's kingdom was identified as a Gepid rather than a Hunnic kingdom from the fact that the western part of the Hunnic empire had been almost entirely Germanic in population.\n",
"The attila is an elaborately braided Hungarian shell-jacket or short coat, decorated with lace and knots. Historically it was part of the uniform of the Hungarian cavalry known as hussars (or huszárs). It was a part of the everyday wear of rural men as well as members of the nobility and officials.\n",
"The Hun hordes of Attila, who invaded and conquered much of Europe in the 5th century, may have been Turkic and descendants of the Xiongnu. Some scholars argue that the Huns were one of the earlier Turkic tribes, while others argue that they were of Mongolic origin.\n",
"Attila himself is said to have claimed the titles \"Descendant of the Great Nimrod\", and \"King of the Huns, the Goths, the Danes, and the Medes\"—the last two peoples being mentioned to show the extent of his control over subject nations even on the peripheries of his domain.\n"
] |
why are canker sores, ingrown toenails, and splinters so excrutiatingly painful?
|
Hands, feet, the face, the mouth and the external genitals have a very large number of nerve endings that give a high level of the sense of touch in those parts. Other parts of the body are a lot less sensitive. Some internal organs sense no physical pain at all. It's pretty easy to see why the body has evolved this way: a good sense of touch in the hands and feet is required for climbing trees, peeling fruit, working with tools etc., and being able to accurately feel and taste what you're chewing on can also be the difference between life and death. That the pain caused by a splinter is disproportionate to the problem may be just an evolutionary side-effect.
|
[
"They tend to be painful due to the pressure applied to the nail bed and plate. They can involve destruction of the nail bed. These lesions are not true osteochondromas, rather it is a reactive cartilage metaplasia. The reason it occurs on the dorsal aspect is because the periosteum is loose dorsally but very tightly adherent volarly.\n",
"Symptoms of an ingrown nail include pain along the margins of the nail (caused by hypergranulation that occurs around the aforementioned margins), worsening of pain when wearing tight footwear, and sensitivity to pressure of any kind, even the weight of bedsheets. Bumping of an affected toe can produce sharp and even excruciating pain as the tissue is punctured further by the nail. By the very nature of the condition, ingrown nails become easily infected unless special care is taken early to treat the condition by keeping the area clean. Signs of infection include redness and swelling of the area around the nail, drainage of pus and watery discharge tinged with blood. The main symptom is swelling at the base of the nail on the ingrowing side (though it may be both sides).\n",
"Another implication of tinea pedis, especially for older adults or those with vascular disease, diabetes mellitus, or nail trauma, is onychomycosis of the toenails. Nails become thick, discolored, and brittle, and often onycholysis (painless separation of nail from nail bed) occurs.\n",
"Nails can dry out, just like skin. They can also peel, break, and be infected. Toe infections, for instance, can be caused or exacerbated by dirty socks, specific types of aggressive exercise (long-distance running), tight footwear, and walking unprotected in an unclean environment. Common organisms causing nail infections include yeasts and molds (particularly dermatophytes).\n",
"Leukonychia striata, transverse leukonychia, or Mees' lines are a whitening or discoloration of the nail in bands or \"stria\" that run parallel the lunula (nail base). This is commonly caused by physical injury or disruption of the nail matrix. Common examples include excessive biting or tapping of the nails, trauma or injury from accidents involving doors or windows, and extensive use of manicure. It may also occur in great toenails as a result of trauma from footwear. Alternatively, the condition can be caused by heavy metal poisoning, most commonly by lead. Finally, it can be caused by cirrhosis of the liver or chemotherapy.\n",
"TLP is a harmless problem. These bumps can become notably red or white and are quite tender for up to several days. While the cause of TLP is not known with certainty, most experts feel that local accidental trauma (rubbing, scraping or biting) is a major factor; however, contact reactions to things like certain foods have also been suggested. Lie bumps are not contagious and the discomfort is relatively minor. Typically these lesions heal within a few days with no treatment, though a doctor may refer a patient to an oral pathologist in prolonged cases.\n",
"Epidermophyton is a genus of fungus causing superficial and cutaneous mycoses, including \"E. floccosum\", and causes tinea corporis (ringworm), tinea cruris (jock itch), tinea pedis (athlete’s foot), and tinea unguium (fungal infection of the nail bed).\n"
] |
What is the reason for China's relatively modest nuclear arsenal? Why is China the only nuclear weapons state to have given an unqualified security assurance to non-nuclear-weapon states?
|
Under the theory of nuclear deterrence, most nuclear weapons states have little reason to build beyond that quantity of warheads. It's enough to effectively destroy any country. That's one reason why most nuclear weapons states stop near the 300 mark. The US and Russia are the exception because of their massive arms race during the Cold War.
Source:
The Spread of Nuclear Weapons by Kenneth Waltz and Scott Sagan has a lot on this topic
|
[
"In 2004, China stated that \"among the nuclear-weapon states, China ... possesses the smallest nuclear arsenal,\" implying China has fewer than the United Kingdom's 200 nuclear weapons. Several non-official sources estimate that China has around 400 nuclear warheads. However, U.S. intelligence estimates suggest a much smaller nuclear force than many non-governmental organizations.\n",
"Unlike the United States and Russia where strategic nuclear forces are enumerated by treaty limits and subject to verification, China, a nuclear power since 1964, is not subject to these requirements but currently has a triad structure smaller in size than Russia and the United States. China's nuclear force is closer in number and capability to France or the United Kingdom, making it much smaller than that of the United States or Russia. Their nuclear force is mainly land-based missiles which include ICBMs, IRBMs, tactical ballistic missiles, and cruise missiles. Unlike the US and Russia, China stores an abundance of their missiles in massive underground tunnel complexes; U.S. Representative Michael Turner referring to 2009 Chinese media reports said \"This network of tunnels could be in excess of 5,000 kilometers (3,110 miles) and is used to transport nuclear weapons and forces. The Chinese Army Newsletter calls this system of tunnels the Underground Great Wall of China. China's nuclear warheads are believed to be stored in a central storage facility and not with the launchers.\n",
"China is one of the five nuclear weapons states (NWS) recognized by the Nuclear Non-Proliferation Treaty, which China ratified in 1992. China is the only NWS to give an unqualified security assurance to non-nuclear-weapon states:\n",
"The development of nuclear weapons by the Republic of China has been a contentious issue, as it had been triggered by PRC's first nuclear test in 1964. The U.S., hoping to avoid escalating tensions in the Taiwan Strait, has continually opposed arming the Republic of China with nuclear weapons after 1979. Accordingly, the Republic of China adheres to the principles of the nuclear Non-Proliferation Treaty and has stated that it does not intend to produce nuclear weapons, on an official basis. Past nuclear research by the ROC makes it a \"threshold\" nuclear state.\n",
"According to French newspaper \"Le Monde\", the Chinese nuclear doctrine is to maintain a nuclear force allowing it to deter and respond to a nuclear attack. However, new evolutions show that China could allow use of its nuclear arsenal in more situations.\n",
"China's nuclear forces, in combination with the PLA's conventional forces, served to deter both nuclear and conventional attacks on the Chinese lands. Chinese leaders pledged to not use nuclear weapons first (\"no first use\"), but pledged to absolutely counter-attack with nuclear weapons if nuclear weapons are used against China. China envisioned retaliation against strategic and tactical attacks and would probably strike countervalue rather than counterforce targets. The combination of China's few nuclear weapons and technological factors such as range, accuracy, and response time limited the effectiveness of nuclear strikes against counterforce targets. China has been seeking to increase the credibility of its nuclear retaliatory capability by dispersing and concealing its nuclear forces in difficult terrain, improving their mobility, and hardening its missile silos.\n",
"The number of nuclear warheads in China's arsenal is a state secret. There are varying estimates of the size of China's arsenal. China is estimated by the Federation of American Scientists to have an arsenal of about 260 total warheads as of 2015, which would make it the second smallest nuclear arsenal amongst the five nuclear weapon states acknowledged by the Treaty on the Non-Proliferation of Nuclear Weapons. According to some estimates, the country could \"more than double\" the \"number of warheads on missiles that could threaten the United States by the mid-2020's\".\n"
] |
monte carlo simulation and markov chain or more specifically the setting up of the data.
|
> BUT if you have a - day, theres a i dunno + 10% bonus that it will be a - day tomorrow too.
Then it isn't a Markov chain. A Markov chain's defining property is that the future evolution of the system depends *only* on its current state - it is "memoryless". You could still do a Monte Carlo simulation, since those are much more general.
|
[
"Monte Carlo simulation provides the capability, through sensitivity analysis, to identify single or chains of events. These chains of events can be identified by analyzing the correlations between the main project parameters, such as project duration or cost, and the event chains. These are called “critical events” or “critical chains of events”. By identifying critical events or critical chains of events, we can identify strategies to minimize their negative effects: Avoid, Transfer, Mitigate, or Accept. Event and event chain ranking is performed for all risk categories (schedule-related and non-schedule) as part of one process. Integrated risk probability, impact and score can be calculated using weights for each risk category.\n",
"In statistics, Markov chain Monte Carlo (MCMC) methods comprise a class of algorithms for sampling from a probability distribution. By constructing a Markov chain that has the desired distribution as its equilibrium distribution, one can obtain a sample of the desired distribution by observing the chain after a number of steps. The more steps there are, the more closely the distribution of the sample matches the actual desired distribution.\n",
"Kinetic Monte Carlo (KMC) is a form of computer simulation in which atoms and molecules are allowed to interact at given rate that could be controlled based on known physics. This simulation method is typically used in the micro-electrical industry to study crystal surface growth, and it can provide accurate models surface morphology in different growth conditions on a time scales typically ranging from micro-seconds to hours. Experimental methods such as Scanning Electron Microscopy (SEM), X-ray diffraction, and Transmission Electron Microscopy (TEM), and other computer simulation methods such as Molecular Dynamics (MD), and Monte Carlo (MC) simulation are widely used.\n",
"Markov chain Monte Carlo (MCMC) is a flexible procedure designed to fit a variety of Bayesian models. It is the underlying method used in computational software such as the LaplacesDemon R Package and WinBUGS. The advancements and developments of these types of statistical software have allowed for the growth of Bayes by offering ease of calculation. This is achieved by the generation of samples from the posterior distributions, which are then used to produce a range of options or strategies which are allocated numerical weights. MCMC obtains these samples and produces summary and diagnostic statistics while also saving the posterior samples in the output. The decision maker can then assess the results from the output data set and choose the best option to proceed.\n",
"The kinetic Monte Carlo (KMC) method is a Monte Carlo method computer simulation intended to simulate the time evolution of some processes occurring in nature. Typically these are processes that occur with known transition rates among states. It is important to understand that these rates are inputs to the KMC algorithm, the method itself cannot predict them.\n",
"Once events and event chains are defined, quantitative analysis using Monte Carlo simulation can be performed to quantify the cumulative effect of the events. Probabilities and impacts of risks assigned to activities are used as input data for Monte Carlo simulation of the project schedule. In most projects it is necessary to supplement the event based variance with uncertainties as distributions related to duration, start time, cost, and other parameters.\n",
"Interacting Markov chain Monte Carlo methodologies are a class of mean field particle methods for obtaining random samples from a sequence of probability distributions with an increasing level of sampling complexity. These probabilistic models include path space state models with increasing time horizon, posterior distributions w.r.t. sequence of partial observations, increasing constraint level sets for conditional distributions, decreasing temperature schedules associated with some Boltzmann-Gibbs distributions, and many others. In principle, any Markov chain Monte Carlo sampler can be turned into an interacting Markov chain Monte Carlo sampler. These interacting Markov chain Monte Carlo samplers can be interpreted as a way to run in parallel a sequence of Markov chain Monte Carlo samplers. For instance, interacting simulated annealing algorithms are based on independent Metropolis-Hastings moves interacting sequentially with a selection-resampling type mechanism. In contrast to traditional Markov chain Monte Carlo methods, the precision parameter of this class of interacting Markov chain Monte Carlo samplers is \"only\" related to the number of interacting Markov chain Monte Carlo samplers. These advanced particle methodologies belong to the class of Feynman-Kac particle models, also called Sequential Monte Carlo or particle filter methods in Bayesian inference and signal processing communities. Interacting Markov chain Monte Carlo methods can also be interpreted as a mutation-selection genetic particle algorithm with Markov chain Monte Carlo mutations.\n"
] |
What is the significance in electric and magnetic components of EM radiation being right angles to one another?
|
The components of the electric and magnetic fields are different in different inertial reference frames.
But they can be written in terms of an object called the [electromagnetic field tensor](_URL_0_), which is relatively straightforward to transform between frames.
From this tensor you can construct two invariant quantities, which are the same in **all** inertial frames.
In Gaussian units, they are (**B**^(2) - **E**^(2)) and **E∙B**.
For an electromagnetic wave, it turns out that *both* of these quantities are zero. And since they're invariants, they're zero **in all inertial frames**.
The second one specifically is relevant to your question. If the dot product of two nonzero vectors is zero, they are perpendicular to each other. This means that the electric and magnetic fields in an EM wave are perpendicular **in all inertial frames**. The fact that they're perpendicular in one frame implies that they're perpendicular in all frames.
I'm not sure if this is what you're looking for when you say "significance", but it's an interesting fact nonetheless.
|
[
"Both of these EMFs, despite their apparently distinct origins, are described by the same equation, namely, the EMF is the rate of change of magnetic flux through the wire. (This is Faraday's law of induction, see below.) Einstein's special theory of relativity was partially motivated by the desire to better understand this link between the two effects. In fact, the electric and magnetic fields are different facets of the same electromagnetic field, and in moving from one inertial frame to another, the solenoidal vector field portion of the \"E\"-field can change in whole or in part to a \"B\"-field or \"vice versa\".\n",
"In electrodynamics, linear polarization or plane polarization of electromagnetic radiation is a confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation. See \"polarization\" and \"plane of polarization\" for more information.\n",
"Electromagnetic radiation consists of an electric (E) and magnetic (B) field that oscillate perpendicular to one another and to the propagating direction, a transverse wave. While linearly polarized light occurs when the electric field vector oscillates only in one plane, circularly polarized light occurs when the direction of the electric field vector rotates about its propagation direction while the vector retains constant magnitude. At a single point in space, the circularly polarized-vector will trace out a circle over one period of the wave frequency, hence the name. The two diagrams below show the electric vectors of linearly and circularly polarized light, at one moment of time, for a range of positions; the plot of the circularly polarized electric vector forms a helix along the direction of propagation (k). For left circularly polarized light (LCP) with propagation towards the observer, the electric vector rotates counterclockwise. For right circularly polarized light (RCP), the electric vector rotates clockwise.\n",
"In electromagnetic induction, emf can be defined around a closed loop of conductor as the electromagnetic work that would be done on an electric charge (an electron in this instance) if it travels once around the loop. For a time-varying magnetic flux linking a loop, the electric potential scalar field is not defined due to a circulating electric vector field, but an emf nevertheless does work that can be measured as a virtual electric potential around the loop.\n",
"The two magnetic fields are usually chosen to be perpendicular to each other as this maximizes the NMR signal strength. The frequencies of the time-signal response by the total magnetization (M) of the nuclear spins are analyzed in NMR spectroscopy and magnetic resonance imaging. Both use applied magnetic fields (B) of great strength, often produced by large currents in superconducting coils, in order to achieve dispersion of response frequencies and of very high homogeneity and stability in order to deliver spectral resolution, the details of which are described by chemical shifts, the Zeeman effect, and Knight shifts (in metals). The information provided by NMR can also be increased using hyperpolarization, and/or using two-dimensional, three-dimensional and higher-dimensional techniques.\n",
"Similarly to XMCD, EMCD is a difference spectrum of two EELS spectra taken in a magnetic field with opposite helicities. Under appropriate scattering conditions virtual photons with specific circular polarizations can be absorbed, giving rise to spectral differences. The largest difference is expected between the case where one virtual photon with left circular polarization and one with right circular polarization are absorbed. By closely analyzing the difference in the EMCD spectrum, information can be obtained on the magnetic properties of the atom, such as its spin and orbital magnetic moment.\n",
"In the case of the same linearly polarized antenna, this is the plane containing the magnetic field vector (sometimes called the H aperture) and the direction of maximum radiation. The magnetizing field or \"H\" plane lies at a right angle to the \"E\" plane. For a vertically polarized antenna, the H-plane usually coincides with the horizontal/azimuth plane. For a horizontally polarized antenna, the H-plane usually coincides with the vertical/elevation plane.\n"
] |
Is riding a bike muscle memory?
|
**Edit, Source:** [I am on a course to acquire one of these in Physical Education.](_URL_0_) ~~There's no way to compare it to American qualifications, so I wouldn't bother trying if I were you.~~
> If there's a corresponding track, it would have to be closer to [Advanced Placement](_URL_2_) level courses offered in high school. These courses are not offered to every high school student, and generally only the top students even attempt to take these classes. The coursework is more rigorous and standardized than ordinary high school classes. At the end of AP classes, a standardized test is given, and if you score high enough you receive credit that is transferable to colleges and universities.)
~[the_longest_troll](_URL_1_)
***
Yes and yes.
You know how "riding a bike" is built up of different things that come together to create the act itself, as a whole? These are "sub-routines", they make up the Executive Motor Programme, or skill, which is what riding a bike is.
Novices will begin at the cognitive stage of learning, it won't be "muscle memory", you're just figuring this out.
Then you get better and you kinda get it, you know when you still fuck up in sport but you also manage some pretty decent stuff? That's associative. Regarding riding a bike you're still not in the "muscle memory" sort of league, you'll want to keep both hands on the handlebars, etc, but you're not useless. To be honest, this stage isn't as evident with riding a bike. You don't go straight from Cognitive to Autonomous, but the lines between the stages (Cognitive --- > Associative --- > Autonomous) are more blurry.
Then you have the mastery of the skill which occurs through constant practice of it. Here you can just *do*, you don't even need to think about it (ever get in your car and then just arrive at your destination with no memory of getting there? That's because you're so good at it, you don't need to give it your full attention, so to speak). This is what you're talking about about, this is when you've "grooved" the skill so it means instinctive. I've not ridden a bike in years (my old one broke, can't afford a new one), I'll still be able to get on one and ride as if I'd been riding this whole time. It's a EMP that has been committed to my Long-Term Memory, it isn't going anywhere because LTM is, theoretically, unlimited.
Kinesthesis. It's one of the senses that most people forget and plays a big part in balance. For instance, stand on one leg. Now close your eyes. You can feel yourself making sure you don't lose your balance, right? It's involuntary but it is something you also have control over.
|
[
"Muscle memory is a form of procedural memory that involves consolidating a specific motor task into memory through repetition, which has been used synonymously with motor learning. When a movement is repeated over time, a long-term muscle memory is created for that task, eventually allowing it to be performed without conscious effort. This process decreases the need for attention and creates maximum efficiency within the motor and memory systems. Examples of muscle memory are found in many everyday activities that become automatic and improve with practice, such as riding a bicycle, typing on a keyboard, entering a PIN, playing a musical instrument, poker, martial arts or even dancing.\n",
"Muscle memory has been used to describe the observation that various muscle-related tasks seem to be easier to perform after previous practice, even if the task has not been performed for a while. It is as if the muscles “remember”. The term could relate to tasks as disparate as playing the clarinet and weight-lifting, i.e., the observation that strength trained athletes experience a rapid return of muscle mass and strength even after long periods of inactivity.\n",
"The mechanisms implied for the muscle memory suggest that it mainly related to strength training, and a 2016 study conducted at Karolinska Institutet in Stockholm, Sweden, failed to find a memory effect of endurance training. \n",
"Recumbent cycles offer the possibility of combined hand and foot power inputs, and thus the potential for a full-body workout, and the option for persons with a weak or missing leg(s) to power a cycle. In one recumbent tricycle design the user makes the two front wheels change direction by shifting his center of weight, and moves forward by rotating the rear wheel. There are also hybrids between a handcycle, a recumbent bike and a tricycle; these bikes enable cycling by use of legs, despite a spinal cord injury\n",
"BULLET::::- Muscle memory – the retention in the brain of memories of certain muscle movements, often enabling those specific movement to be duplicated in the future. Also termed motor learning, it is a form of procedural memory that involves consolidating a specific motor task into memory through repetition. When a movement is repeated over time, a long-term muscle memory is created for that task, eventually allowing it to be performed without conscious effort. This process decreases the need for attention and creates maximum efficiency within the motor and memory systems. Examples of muscle memory are found in many everyday activities that become automatic and improve with practice, such as riding a bicycle, typing on a keyboard, rote typing in a bank personal identification number (PIN), playing a melody or phrase on a musical instrument, playing video games, or performing different algorithms for a Rubik's Cube.\n",
"BULLET::::- Muscle memory – the retention in the brain of memories of certain muscle movements, often enabling those specific movement to be duplicated in the future. Also termed motor learning, it is a form of procedural memory that involves consolidating a specific motor task into memory through repetition. When a movement is repeated over time, a long-term muscle memory is created for that task, eventually allowing it to be performed without conscious effort. This process decreases the need for attention and creates maximum efficiency within the motor and memory systems. Examples of muscle memory are found in many everyday activities that become automatic and improve with practice, such as riding a bicycle, typing on a keyboard, rote typing in a bank personal identification number (PIN), playing a melody or phrase on a musical instrument, playing video games, or performing different algorithms for a Rubik's Cube.\n",
"Bicycles are often used by people seeking to improve their fitness and cardiovascular health. In this regard, cycling is especially helpful for those with arthritis of the lower limbs who are unable to pursue sports that cause impact to the knees and other joints. Since cycling can be used for the practical purpose of transportation, there can be less need for self-discipline to exercise.\n"
] |
what it that feeling of horrible burning when water goes up your nose when diving into a pool or just taking a shower and reaching down for something?
|
The main reason why water burns when it goes up your nose is because the salinity of the water does not match the salinity of the cells in your body. The salinity of freshwater is much lower than your body, so when water gets into your nose and into your sinuses, some of the cells that line the sinus and nasal cavities burst open and die because they rapidly suck in water - like overfilling a water balloon. Your body responds by rapidly secreting mucus to coat the remaining cells and protect them from the water.
This whole thing involves three steps: (1) osmosis of water into the nasal cells; (2) many cells burst (cell lysis), and (3) the responds by releasing mucus.
[Link](_URL_0_)
|
[
"Some warning signs that occur include pain, burning and numbness at the place of infection. Also people with the disease experience sleeplessness, headaches, irritability, difficulty swallowing and throat spasms. They may experience fear of water (hydrophobia).\n",
"Erythema ab igne (EAI), also known as hot water bottle rash, is a skin condition caused by long-term exposure to heat (infrared radiation). Prolonged thermal radiation exposure to the skin can lead to the development of reticulated erythema, hyperpigmentation, scaling and telangiectasias in the affected area. Some people may complain of mild itchiness and a burning sensation, but often, unless a change in pigmentation is seen, it can go unnoticed.\n",
"For individuals not previously exposed to OC effects, the general feelings after being sprayed can be best likened to being \"set alight.\" The initial reaction should the spray be directed at the face, is the completely involuntary closing of the eyes (sometimes described as leading to a disconcerting sensation of the eyelids \"bubbling and boiling\" as the chemical acts on the skin), an instant sensation of the restriction of the airways and the general feeling of sudden and intense, searing pain about the face, nose, and throat. Coughing almost always follows the initial spray.\n",
"Because of vigorous reaction of quicklime with water, quicklime causes severe irritation when inhaled or placed in contact with moist skin or eyes. Inhalation may cause coughing, sneezing, labored breathing. It may then evolve into burns with perforation of the nasal septum, abdominal pain, nausea and vomiting. Although quicklime is not considered a fire hazard, its reaction with water can release enough heat to ignite combustible materials.\n",
"The uncomfortable sensation of breathing in the ammonia-like fumes has been described as \"the head 'exploding', the eyes 'watering' and intense irritation of the nasal passages\" – such that the initial headache was quickly forgotten.\n",
"That night, Fanshawe has a nightmare where he goes to the bathroom to get a drink, only to find that the water in the cup is cloudy and contaminated. Hearing the water in the bathtub stop dripping, Fanshawe turns around, only to be terrified by a shadowy figure lurking in the darkness wearing a skull mask.\n",
"Inhalation, the most common route of exposure, causes a burning pain and irritation throughout the respiratory tract, nosebleed (epistaxis), laryngitis, sneezing, coughing, vomiting, difficult breathing (dyspnea), and in severe cases of exposure, can cause fatal pulmonary edema, pneumonitis, or respiratory failure. Ingestion results in severe pain, nausea, vomiting, and tissue damage. The results of eye exposure can range from stinging, burning pain and strong irritation to blistering and scarring of the cornea, along with blepharospasm, lacrimation, and edema of the eyelids and periorbital area. The eyes can swell shut, which can keep the eyes safe from further exposure. The most severe consequences of eye exposure to lewisite are globe perforation and blindness. Generalised symptoms also include restlessness, weakness, hypothermia and low blood pressure.\n"
] |
What are the pros and cons of HDL, LDL, and omega-3 fatty acids? (Also what are omega-3 fatty acids?)
|
Hi there.
After digestion, your lipids are packed into droplets known as chylomicrons. From there, they are transported to the liver and re-packaged as lipoproteins (containing cholesterol, triglycerides, fatty acid etc).
So as these lipoproteins, fresh from the liver, transport fatty acids, cholesterol and triglycerides around the body via the circulatory system. They start off as VLDL (Very low-density lipoproteins) and as they move around the body, depositing and distributing fatty acids and cholesterol, they come into contact with HDL which in turn removes part of their core (triglycerides) via breakdown of lipids. Also, the high triglycerides content in VLDL is exchanged for cholesterol with HDL.
So after the exchange of triglycerides and cholesterol with HDL, VLDL is changed into LDL. LDL has a high cholesterol content due to this process. As it moves around the body, distributing cholesterol and triglycerides, some of the cholesterol are distributed onto the walls of the blood vessels. As time passes, this cholesterol deposition will increase in size due to more cholesterol being deposited. Another term for this mass of cholesterol is plaque. Inflammatory responses from the body will cause this plaque to be formed and eventually break off. This often resets in heart attack if the plaque is large enough to enter and clog up the coronary artery.
Pros of LDL:
- distribute triglycerides, cholesterol, lipids etc around the body for functioning
- helps to regulate the body's lipid balance (homeostasis)
Cons of LDL:
- may result in cardiovascular diseases when in excess
- too much of LDL can also bring by obesity, hypertension, diabetes mellitus (II) etc
HDL are deployed by the liver to collect back cholesterol, and also to exchange these cholesterol for triglycerides with VLDL as mentioned earlier on. Basically, HDL acts as a cleaning agent in the system, clearing some of the cholesterol that may result in cardiovascular disease in the body and in particular, the circulatory system.
Pros of HDL:
- Cleans up the circulatory system of cholesterol
- Helps regulate the balance of lipids
Cons of HDL:
- Not too sure
|
[
"Omega-3 fatty acids are polyunsaturated fatty acids (PUFAs) that are essential for proper brain and cognitive development. They also play a large role in the production of anti-inflammatory eicosanoids, which has been shown to reduce the risk of cardiovascular disease and other inflammatory diseases. There are three types of omega-3 fatty acids; namely alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Alpha-linoleic acid is an essential fatty acid, and is the form that is most common and widespread of the omega-3 fatty acids. Vegan sources of ALA include plant oils, nuts, flaxseed (linseed), and soy. While DHA and EPA are very important and have major implications in cognition, they are not considered essential as dogs are able to synthesize them from ALA. However, the conversion rate is relatively low, and supplementation of DHA and EPA is often helpful. Sources of DHA and EPA are also generally less widespread, and although most of the market sources of these PUFAs are from fish and fish oil, they can be sourced from algae for a vegan formulation.\n",
"The omega-3 fatty acids are a key nutrient in cognition for felines. They are essential for felines as they cannot be synthesized naturally and must be obtained from the diet. Omega-3 fatty acids that support brain development and function are alpha-linolenic acid, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Fish oils, fish and other marine sources provide a very rich source of DHA and EPA. Alpha-linolenic acid can be acquired from oils and seeds.\n",
"The omega-3 fatty acids are a key nutrient in cognition for felines. They are essential for felines as they cannot be synthesized naturally and must be obtained from the diet. Omega-3 fatty acids that support brain development and function are alpha-linolenic acid, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Fish oils, fish and other marine sources provide a very rich source of DHA and EPA. Alpha-linolenic acid can be acquired from oils and seeds.\n",
"Omega-3 fatty acids may also be used as a treatment for bipolar disorder, particularly as a supplement to medication. An initial clinical trial by Stoll et al. produced positive results. However, since 1999 attempts to confirm this finding of beneficial effects of omega-3 fatty acids in several larger double-blind clinical trials have produced inconclusive results. It was hypothesized that the therapeutic ingredient in omega-3 fatty acid preparations is eicosapentaenoic acid (EPA) and that supplements should be high in this compound to be beneficial. A 2008 Cochrane systematic review found limited evidence to support the use of Omega-3 fatty acids to improve depression but not mania as an adjunct treatment for bipolar disorder.\n",
"BULLET::::- Fat intake: Consuming high amounts of certain fats including saturated fats, trans fats and omega-6 fatty acids likely contributes to AMD, while monounsaturated fats are potentially protective. In particular, omega-3 fatty acids may decrease the risk of AMD.\n",
"Although omega-3 fatty acids, which are polyunsaturated fatty acids (PUFA), are a popular treatment for children with ASD, there is very little high-quality scientific evidence supporting their effectiveness, and further research is needed.\n",
"Omega-3 carboxylic acids (Epanova) is an FDA approved prescription medication used alongside a low fat and low cholesterol diet that lowers high triglyceride (fat) levels in adults with very high levels. This was the third class of fish oil-based drug to be approved for use as a drug. The first approval was granted in the US came in 2014. These fish oil drugs are similar to fish oil dietary supplements but the ingredients are better controlled and have been tested in clinical trials.\n"
] |
how does the air stay so hot in the nighttime when the sun isn’t even out? and how is it that the sun makes the temperature only like 5-10 degrees warmer during the daytime in the summer?
|
The same reason the inside of an oven doesn't return to room temperature the instant you turn it off. Both the atmosphere and the ground absorb heat during the daytime. It takes time for this heat to dissipate after the sun sets. Furthermore, and this answers some of the second part of your question as well, air doesn't stay in one place. There are both local and global weather phenomenon that move air around, so warm air can be coming from elsewhere on the planet. As for your claim that it's only 5-10 degrees (I assume you mean Fahrenheit) cooler at night, that's your personal observation in your specific location for a short period of time, not fact. There are tons of historical weather records from all over the world at different times of year and different points in history that show the actual daily, weekly, monthly, and seasonal highs and lows, and I think you'll find there's a ton of variation.
|
[
"BULLET::::- Due to the thin atmosphere, the temperature difference between day and night is much larger than on Earth, typically around 70 °C (125 °F). However, the day/night temperature variation is much lower during dust storms when very little light gets through to the surface even during the day, and instead warms the middle atmosphere.\n",
"When the sun warms the ground, it will warm some features more than others (such as rock faces or large buildings), and these set off thermals which rise through the air. Sometimes these may be a simple rising column of air; more often, they are blown sideways in the wind and will break off from the source, with a new thermal forming later.\n",
"Temperature variations are closely correlated with direct sunlight. The sun quickly warms the ground by a few degrees, which in turn warms the air close to the ground. This air cools to reach equilibrium with the mean air temperature very quickly when the sky becomes overcast. The layer of air within half a metre of the ground in the valleys also exhibit different temperatures at night to the air layer above it. During the clear nights of the dry season, the ground cools quickly cooling the air next to it. This leads to katabatic winds from the ridges into the valleys resulting in the valley bottoms being colder than the higher ridges flanking them. Baker found that the Teleki valley was regularly 2 °C colder at night than the surrounding ridges. This has forced plants such as the senecios and lobellias to be tall to avoid key parts freezing, as freezing is lethal for plants.\n",
"When the sun is in its northern declination northerly places will heat up and it will be cold towards the south. Then the northern air will expand in a southerly direction because of the heat due to the contraction of the southern air. Therefore most of the summer winds are merits and most of the winter winds are not.\n",
"Because of its temperature, the atmosphere emits infrared radiation. For example, on clear nights Earth's surface cools down faster than on cloudy nights. This is because clouds (HO) are strong absorbers and emitters of infrared radiation. This is also why it becomes colder at night at higher elevations.\n",
"The slow night-time cooling of a home after its external brick wall has been heated by the sun is one example of thermal lag. Thermal lag is the reason the high temperatures in summer continue to increase after the summer solstice (in this case, it is termed seasonal lag), and it is the reason a day's high temperature peaks in the afternoon instead of when the Sun is at its peak (12 noon).\n",
"At and near the poles, the Sun never rises very high above the horizon, even in summer, which is one of reasons why these regions of the world are consistently cold in all seasons (others include the effect of albedo, the relative increased reflection of solar radiation of snow and ice). Even at the summer solstice, when the Sun reaches its highest point above the horizon at noon, it is still only 23.5° above the horizon at the poles. Additionally, as one approaches the poles the apparent path of the Sun through the sky each day diverges increasingly from the vertical. As summer approaches, the Sun rises and sets become more northerly in the north and more southerly in the south. At the poles, the path of the Sun is indeed a circle, which is roughly equidistant above the horizon for the entire duration of the daytime period on any given day. The circle gradually sinks below the horizon as winter approaches, and gradually rises above it as summer approaches. At the poles, apparent sunrise and sunset may last for several days.\n"
] |
When does a comet stop moving?
|
You can think of a comet entering our solar system as a ball rolling down a hill. As it gets closer and closer to the sun, it'll speed up more and more. When it heads away from the sun, it'll be slowing down, like a ball going uphill. This is because of the effect of the sun's gravity. It won't otherwise come to a stop, per se. It'll be in some sort of orbit.
It is, however, possible for something else to change that orbit. For example, Jupiter has redirected comets into new orbits when comets have passed too close to it.
|
[
"Each time a comet swings by the Sun in its orbit, some of its ice vaporizes and a certain amount of meteoroids will be shed. The meteoroids spread out along the entire orbit of the comet to form a meteoroid stream, also known as a \"dust trail\" (as opposed to a comet's \"gas tail\" caused by the very small particles that are quickly blown away by solar radiation pressure).\n",
"If a comet is traveling fast enough, it may leave the Solar System. Such comets follow the open path of a hyperbola, and as such they are called hyperbolic comets. To date, comets are only known to be ejected by interacting with another object in the Solar System, such as Jupiter. An example of this is thought to be Comet C/1980 E1, which was shifted from a predicted orbit of 7.1 million years around the Sun, to a hyperbolic trajectory, after a 1980 close pass by the planet Jupiter.\n",
"Comets sometimes may disappear because of orbital derangement from an ellipse to a parabola or a hyperbola. Sir Isaac Newton showed that a body controlled by the Sun moves in a conic section—that is, an ellipse, a parabola or a hyperbola. Because the latter two are open curves, a comet which pursued such a path would go off into space never to reappear. A derangement of orbit from closed to open curve has doubtless happened often.\n",
"A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred metres to tens of kilometres across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times the Earth's diameter, while the tail may stretch one astronomical unit. If sufficiently bright, a comet may be seen from the Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures.\n",
"As it enters the atmosphere of Earth, Diana remarks that the comet is slowing down, \"as if it's coming in for a landing.\" As she tells Ryland the co-ordinates of where the comet's trajectory will land it, Dennis states that it is near Mount Rainier, their \"back yard.\" Arriving at the landing spot of the comet, a multitude of cameramen and reporters have set up. Diana looks on as the comet slowly comes in to land, hovering over a lake and causing ripples to form in the water. While emitting a sound, the comet begins to shrivel and lose its cohesion. Seconds later, the ball of light explodes, sending a shock-wave that knocks over the onlookers. Returning to their feet, they discover the comet is gone, and thousands of people have appeared.\n",
"It is now believed that some of the dust, icy chunks, and other material coming off the ends of the comet are moving slowly enough to be captured by even the weak gravity of the comet. This material then falls back into the lowest point—the middle.\n",
"Occasionally, the shower intensifies when the planets steer the one-revolution dust trail of the comet into Earth's path, an event that happens about once every 60 years. This results in an April Lyrid meteor outburst. The one-revolution dust trail is dust that has completed one orbit: the stream of dust released in the return of the comet prior to the current 1862 return. This mechanism replaces earlier ideas that the outbursts were due to a cloud of dust moving in a 60-year orbit. In 1982, amateur astronomers counted 90 April Lyrids per hour at the peak and similar rates were seen in 1922. A stronger storm of up to 700 per hour occurred in 1803, observed by a journalist in Richmond, Virginia:\n"
] |
why is it racist to do an asian accent but not racist to to a british or an australian etc. one
|
If you are a white American, it is because that is the same race. Brits and Australians speak the same language as you, just with different accents. An Asian has learned your language even though it is not their native tongue, and you would be mocking them.
|
[
"In response to the issue, Bollywood star Amitabh Bachchan turned down an honorary doctorate from the Queensland University of Technology. Fellow Indian actor, Aamir Khan, has condemned the attacks, stating that, \"[It is] most disturbing to hear about racist attacks on Indians living in Australia. Quite a shame. While this doesn't mean that all Australians are racists, the frequency and seriousness of such attacks, I think, calls for an extra ordinary reaction from the Australian authorities, and while we want action to be taken by authorities in Australia, equally we should remember all the various crimes against foreigners who visit India.\"\n",
"Another form of discrimination towards British Indians is stereotyping, one example is British Asians stereotyped as being the majority of newsagent and convenience store shopkeepers, the stereotype \"Paki shop\"; and also making up a majority of doctors. This stereotype was made fun of in the television and radio sketches of Goodness Gracious Me by four British Indian comedy actors. In the comedy sketch Little Britain, a British Indian character called Meera continuously receives racist comments from weight loss advisor Marjorie Dawes who always makes it known that she does not understand a word of what Meera says, although it is completely obvious to the surrounding people and the viewer.\n",
"This isn't to say that the people are necessarily racist or have bad intentions with these umbrella groupings—it's more of a symptom of a history of relatively little immigration from East Asian countries until the 21st century, combined with relatively little amounts of travel to Asian countries on the part of the Spaniards until recent times. Spain had been, to some extent, a closed country, even though it is opening up a lot more now these days, with a lot more Spaniards who travel and work in Asian countries, especially China. As Kim says in the blog post, “it’s not racism. It’s ignorance about Asian cultures.” \n",
"I am proud of my white skin, just as a Chinese is proud of his yellow skin, a Japanese of his brown skin, and the Indians of their various hues from black to coffee-coloured. Anybody who is not proud of his race is not a man at all. And any man who tries to stigmatize the Australian community as racist because they want to preserve this country for the white race is doing our nation great harm... I reject, in conscience, the idea that Australia should or ever can become a multi-racial society and survive.\n",
"I am proud of my white skin, just as a Chinese is proud of his yellow skin, a Japanese of his brown skin, and the Indians of their various hues from black to coffee-coloured. Anybody who is not proud of his race is not a man at all. And any man who tries to stigmatize the Australian community as racist because they want to preserve this country for the white race is doing our nation great harm... I reject, in conscience, the idea that Australia should or ever can become a multi-racial society and survive.\n",
"I am proud of my white skin, just as a Chinese is proud of his yellow skin, a Japanese of his brown skin, and the Indians of their various hues from black to coffee-coloured. Anybody who is not proud of his race is not a man at all. And any man who tries to stigmatize the Australian community as racist because they want to preserve this country for the white race is doing our nation great harm... I reject, in conscience, the idea that Australia should or ever can become a multi-racial society and survive.\n",
"I am proud of my white skin, just as a Chinese is proud of his yellow skin, a Japanese of his brown skin, and the Indians of their various hues from black to coffee-coloured. Anybody who is not proud of his race is not a man at all. And any man who tries to stigmatize the Australian community as racist because they want to preserve this country for the white race is doing our nation great harm... I reject, in conscience, the idea that Australia should or ever can become a multi-racial society and survive.\n"
] |
why are so many of the world's greatest classic rock bands from england? what were the influences at that time and when did their rising popularity start to decline?
|
Two reasons.
1. The Beatles. They were HUGE, and seemingly came from nowhere. They became the most popular band in history, and inspired many small time bands and musicians in England to try and go big as well.
2. Empire. GB used to basically rule the world, and a lot of the world took up parts of British culture because of it. This probably allowed a band like the Beatles to have success a lot faster, as most of the world was already attuned to the British taste in music and art.
|
[
"At the same time, rock and roll was played in Britain after 1955. The British product has generally been considered less successful than the American version of the genre at the time, and made very little international or lasting impact. However, it was important in establishing British youth and popular music culture and was a key factor in subsequent developments that led to the British Invasion of the mid-1960s. Since the 1960s some stars of the genre, most notably Cliff Richard, have managed to sustain very successful pop careers and there have been periodic revivals of this form of music.\n",
"In parts the 20th century, influences from the music of the United States became dominant in popular music. Following this was the explosion of the British Invasion, while subsequent notable movements in British music include the new wave of British heavy metal and Britpop. The United Kingdom has one of the world's largest music industries today, with many British musicians having influenced modern music.\n",
"In general, early British rock and roll was a second-class product and made little impact on the American market, where British acts before 1963 were almost unknown. In Britain too their significance was limited. British rhythm and blues bands like the Rolling Stones and the Yardbirds deliberately turned away from rock and roll towards its sources in America, and even the subsequent generation of beat bands that owed much more to rock and roll, frequently covered songs by American artists like Chuck Berry, but rarely used material from British acts. Early British rock and roll was undoubtedly an inspiration and influence on the instrumentation and shape of the beat music that spearheaded the British Invasion, but it had to be changed significantly into something new and vital in order to have any impact outside of its own borders.\n",
"The emergence of American rock and roll as a major international force in popular music in the mid-1950s led to its emulation in Britain, which shared a common language and many cultural connections. The British product has generally been considered inferior to the American version of the genre, and made very little international or lasting impact. However, it was important in establishing British youth and popular music culture and was a key factor in subsequent developments that led to the 'British Invasion' of the mid-1960s. Since the 1960s some stars of the genre, most notably Cliff Richard, have managed to sustain very successful careers and there have been periodic revivals of this form of music.\n",
"The success of UK artists in the US during the early 2010s led to some claiming a new British Invasion was taking place, as British musicians took their largest ever share of the US album charts year-on-year between 2011 (11.7% of US market), 2012 (13.7% of US market), 2013 and 2014. Notable British musicians achieving global success at the beginning of the 2010s include One Direction, Little Mix, Adele and Mumford & Sons.\n",
"Some British rock bands that began their careers in the British Invasion 60s, notably The Rolling Stones, The Who and The Kinks, also developed their own particular styles and expanded their international fan base during 1970s, but would be joined by new acts in new styles and subgenres.\n",
"By the latter half of the decade British music was declining in popularity in the United States. Oasis and Blur were not considered phenomenons but one-hit wonders stateside. Various Electronica styles were less well received in America then at home while genres that were popular in the United States such as nu metal were not picked up by UK artists. British \"quirkiness\" and regional sensibilities that once were considered strengths there were now considered weakness by the increasingly oligarchic American music industry that was interested in marketing to young teens.\n"
] |
Does the pull of gravity increase or decrease as you approach the center of a mass?
|
I assume when you say "approach the CoM", you mean drilling a borehole.
The [Shell Theorem](_URL_0_) states that it decreases. Assuming the body in question is radially uniform, the gravity at a point inside the body is equal to the gravity pull as if the mass above you (i.e. the "shell" of earth above you) didn't exist.
For instance, if you were 10km inside earth, the surface gravity there would be equal as if the first 10km of earth was "shaved" off, and you were standing on said shaved earth. Hope that made sense.
|
[
"The acceleration due to gravity depends on the gravity of the mass, which rests inside of the object. The gravity decreases at longer distance between centers of mass. The acceleration due to gravity furthermore is influenced by the rotation of the earth. As centrifugal force increases at longer earth's axis distance, thus centrifugal force is highest at the equator and lowest the poles.\n",
"In the gravity field due to a point mass or spherical mass, for a uniform rod oriented in the direction of gravity, the tensile force at the center is found by integration of the tidal force from the center to one of the ends. This gives , where is the standard gravitational parameter of the massive body, is the length of the rod, is rod's mass, and is the distance to the massive body. For non-uniform objects the tensile force is smaller if more mass is near the center, and up to twice as large if more mass is at the ends. In addition, there is a horizontal compression force toward the center.\n",
"As gravitational pull increases, the magnet's acceleration as it falls will tend to increase, except to the extent that the damping coefficient the magnet is experiencing (as a result of the conductor) increases, combined with the extent that the \"velocity\" of the magnet \"also\" increases – a magnet moving or falling quickly will have its acceleration (i.e., its increase in speed as it falls) reduced more than one moving or falling more slowly, and this effect on acceleration will be even more pronounced if the damping coefficient of the conductor is high.\n",
"In the absence of other forces, gravity results in a constant downward acceleration of every freely moving object. Near Earth's surface the acceleration due to gravity is and the gravitational force on an object of mass \"m\" is . It is convenient to imagine this gravitational force concentrated at the center of mass of the object.\n",
"where formula_8 is the acceleration due to gravity, formula_9 is the horizontal distance from the rear axle to the center of mass, and formula_4 is the vertical distance from the ground to the center of mass. Thus the minimum acceleration required is directly proportional to how far forward the center of mass is located and inversely proportional to how high it is located.\n",
"Figure 3 is a graph showing how gravitational force declines with distance. In this graph, the attractive force decreases in proportion to the square of the distance, while the slope relative to value decreases in direct proportion to the distance. This is why the gradient or tidal force at any point is inversely proportional to the cube of the distance.\n",
"where is the gravitational constant and is the mass of the body. As long as the total force is nonzero, this equation has a unique solution, and it satisfies the torque requirement. A convenient feature of this definition is that if the body is itself spherically symmetric, then lies at its center of mass. In general, as the distance between and the body increases, the center of gravity approaches the center of mass.\n"
] |
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