Vacuum is space devoid of matter. The word stems from the Latin adjective vacuus for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists discuss ideal test results that would occur in a perfect vacuum, which they sometimes call "vacuum" or free space, use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is lower than atmospheric pressure; the Latin term in vacuo is used to describe an object, surrounded by a vacuum. The quality of a partial vacuum refers to how it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressure by around 20%. Much higher-quality vacuums are possible. Ultra-high vacuum chambers, common in chemistry and engineering, operate below one trillionth of atmospheric pressure, can reach around 100 particles/cm3.
Outer space is an higher-quality vacuum, with the equivalent of just a few hydrogen atoms per cubic meter on average in intergalactic space. According to modern understanding if all matter could be removed from a volume, it would still not be "empty" due to vacuum fluctuations, dark energy, transiting gamma rays, cosmic rays and other phenomena in quantum physics. In the study of electromagnetism in the 19th century, vacuum was thought to be filled with a medium called aether. In modern particle physics, the vacuum state is considered the ground state of a field. Vacuum has been a frequent topic of philosophical debate since ancient Greek times, but was not studied empirically until the 17th century. Evangelista Torricelli produced the first laboratory vacuum in 1643, other experimental techniques were developed as a result of his theories of atmospheric pressure. A torricellian vacuum is created by filling a tall glass container closed at one end with mercury, inverting it in a bowl to contain the mercury.
Vacuum became a valuable industrial tool in the 20th century with the introduction of incandescent light bulbs and vacuum tubes, a wide array of vacuum technology has since become available. The recent development of human spaceflight has raised interest in the impact of vacuum on human health, on life forms in general; the word vacuum comes from Latin, meaning'an empty space, void', noun use of neuter of vacuus, meaning "empty", related to vacare, meaning "be empty". Vacuum is one of the few words in the English language that contains two consecutive letters'u'. There has been much dispute over whether such a thing as a vacuum can exist. Ancient Greek philosophers debated the existence of a vacuum, or void, in the context of atomism, which posited void and atom as the fundamental explanatory elements of physics. Following Plato the abstract concept of a featureless void faced considerable skepticism: it could not be apprehended by the senses, it could not, provide additional explanatory power beyond the physical volume with which it was commensurate and, by definition, it was quite nothing at all, which cannot rightly be said to exist.
Aristotle believed that no void could occur because the denser surrounding material continuum would fill any incipient rarity that might give rise to a void. In his Physics, book IV, Aristotle offered numerous arguments against the void: for example, that motion through a medium which offered no impediment could continue ad infinitum, there being no reason that something would come to rest anywhere in particular. Although Lucretius argued for the existence of vacuum in the first century BC and Hero of Alexandria tried unsuccessfully to create an artificial vacuum in the first century AD, it was European scholars such as Roger Bacon, Blasius of Parma and Walter Burley in the 13th and 14th century who focused considerable attention on these issues. Following Stoic physics in this instance, scholars from the 14th century onward departed from the Aristotelian perspective in favor of a supernatural void beyond the confines of the cosmos itself, a conclusion acknowledged by the 17th century, which helped to segregate natural and theological concerns.
Two thousand years after Plato, René Descartes proposed a geometrically based alternative theory of atomism, without the problematic nothing–everything dichotomy of void and atom. Although Descartes agreed with the contemporary position, that a vacuum does not occur in nature, the success of his namesake coordinate system and more implicitly, the spatial–corporeal component of his metaphysics would come to define the philosophically modern notion of empty space as a quantified extension of volume. By the ancient definition however, directional information and magnitude were conceptually distinct. In the medieval Middle Eastern world, the physicist and Islamic scholar, Al-Farabi, conducted a small experiment concerning the existence of vacuum, in which he investigated handheld plungers in water, he concluded that air's volume can expand to fill available space, he suggested that the concept of perfect vacuum was incoherent. However, according to Nader El-Bizri, the physicist Ibn al-Haytham and the Mu'tazili theologians disagreed with Aristotle and Al-Farabi, they supported the existence of a void.
Using geometry, Ibn al-Haytham mathematically demonstrated that place is the imagined three-dimensional void between the inner surfaces of a containing body. According to Ahmad Dallal, Abū Rayhān al-Bīrūnī states that "there is no observable
The Hillsborough disaster was a fatal human crush during an FA Cup semi-final football match between Liverpool and Nottingham Forest at Hillsborough Stadium in Sheffield, England, on 15 April 1989. With 96 fatalities and 766 injuries, it remains the worst disaster in British sporting history; the crush occurred in the two standing-only central pens in the Leppings Lane stand, allocated to Liverpool supporters. Shortly before kick-off, in an attempt to ease overcrowding outside the entrance turnstiles, the police match commander, chief superintendent David Duckenfield, ordered exit gate C to be opened, leading to an influx of more supporters to the overcrowded central pens. In the days and weeks following the disaster, police fed false stories to the press suggesting that hooliganism and drunkenness by Liverpool supporters were the root causes of the disaster. Blaming of Liverpool fans persisted after the Taylor Report of 1990, which found that the main cause of the disaster was a failure of control by South Yorkshire Police.
Following the Taylor report, the Director of Public Prosecutions ruled there was no evidence to justify prosecution of any individuals or institutions. The disaster led to a number of safety improvements in the largest English football grounds, notably the elimination of fenced standing terraces in favour of all-seater stadiums in the top two tiers of English football; the first coroner's inquests into the Hillsborough disaster, completed in 1991, ruled all deaths that occurred that day to be accidental. Families rejected the original coroner's findings, their fight to have the matter re-opened persisted, despite Lord Justice Stuart-Smith concluding in 1997 there was no justification for a new inquiry. Private prosecutions brought by the Hillsborough Families Support Group against Duckenfield and his deputy Bernard Murray failed in 2000. In 2009, a Hillsborough Independent Panel was formed to review all evidence. Reporting in 2012, it confirmed Taylor's 1990 criticisms, while revealing new details about the extent of police efforts to shift blame onto fans, the role of other emergency services, the error of the first coroner's inquests.
The panel's report resulted in the previous findings of accidental death being quashed, the creation of new coroner's inquests. It produced two criminal investigations led by police in 2012: Operation Resolve to look into the causes of the disaster, by the Independent Police Complaints Commission to examine actions by police in the aftermath; the second coroner's inquests were held from 1 April 2014 to 26 April 2016. They ruled that the supporters were unlawfully killed due to grossly negligent failures by police and ambulance services to fulfil their duty of care to the supporters; the inquests found that the design of the stadium contributed to the crush, that supporters were not to blame for the dangerous conditions. Public anger over the actions of his force during the second inquests led the SYP chief constable David Crompton to be suspended following the verdict. In June 2017, six people were charged with various offences including manslaughter by gross negligence, misconduct in public office and perverting the course of justice for their actions during and after the disaster.
The Crown Prosecution Service subsequently dropped all charges against one of the defendants. Hillsborough Stadium in Sheffield, the home of Sheffield Wednesday, was selected by the Football Association as a neutral venue to host the FA Cup semi-final between Liverpool and Nottingham Forest football clubs. Kick-off was scheduled for 3:00 pm on 15 April, fans were advised to take up positions 15 minutes beforehand. At the time of the disaster, most English football stadiums had high steel fencing between the spectators and the playing field in response to both friendly and hostile pitch invasions. Hooliganism had affected the sport for some years, was virulent in England. From 1974, when these security standards were put in place, crushes occurred in several English stadiums. A report by Eastwood & Partners for a safety certificate for the stadium in 1978 concluded that although it failed to meet the recommendations of the Green Guide, a guide to safety at sports grounds, the consequences were minor.
It emphasised. Risks associated with confining fans in pens were highlighted by the Committee of Inquiry into Crowd Safety at Sports Grounds after the Bradford City stadium fire in May 1985, it made recommendations on the safety of crowds penned within fences, including that "all exit gates should be manned at all times... and capable of being opened from the inside by anyone in an emergency". Hillsborough hosted five FA Cup semi-finals in the 1980s. A crush occurred at the Leppings Lane end of the ground during the 1981 semi-final between Tottenham Hotspur and Wolverhampton Wanderers after hundreds more spectators were permitted to enter the terrace than could safely be accommodated, resulting in 38 injuries, including broken arms and ribs. Police believed there had been a real chance of fatalities had swift action not been taken, recommended the club reduce its capacity. In a post-match briefing to discuss the incident, Sheffield Wednesday chairman Bert McGee remarked: "Bollocks—no one would have been killed".
The incident nonetheless prompted Sheffield Wednesday to alter the layout at the Leppings Lane end, dividing the terrace into three separate pens to restrict sideways movement. This 1981 change and other changes to the stadium invalidated the stadium's safety certificate; the safety certificate was never renewed and the stated capacity of the stadium was never changed. The terrace was divided into five pens when the
A jack, screwjack or jackscrew is a mechanical device used as a lifting device to lift heavy loads or to apply great forces. A mechanical jack employs a screw thread for lifting heavy equipment. A hydraulic jack uses hydraulic power; the most common form is a car jack, floor jack or garage jack, which lifts vehicles so that maintenance can be performed. Jacks are rated for a maximum lifting capacity. Industrial jacks can be rated for many tons of load; the personal name Jack, which came into English usage around the thirteenth century as a nickname form of John, came in the sixteenth century to be used as a colloquial word for'a man'. From here, the word was'applied to things which in some way take the place of a lad or man, or save human labour'; the first attestation in the Oxford English Dictionary of jack in the sense'a machine portable, for lifting heavy weights by force acting from below' is from 1679, referring to'an Engine used for the removing and commodious placing of great Timber.' Scissor car jacks use mechanical advantage to allow a human to lift a vehicle by manual force alone.
The jack shown at the right is made for a modern vehicle and the notch fits into a hard point on a unibody. Earlier versions have a platform to lift on a vehicle's axle. Electrically operated car scissor jacks are powered by 12 volt electricity supplied directly from the car's cigarette lighter receptacle; the electrical energy is used to power these car jacks to lower automatically. Electric jacks require less effort from the motorist for operation. A house jack called a screw jack, is a mechanical device used to lift buildings from their foundations for repairs or relocation. A series of jacks is used and wood cribbing temporarily supports the structure; this process is repeated. The house jack can be used for jacking carrying beams that have settled or for installing new structural beams. On the top of the jack is a cast iron circular pad that the jacking post rests on; this pad moves independently of the house jack so that it does not turn as the acme-threaded rod is turned with a metal rod.
This piece tilts slightly, but not enough to render the post dangerously out of plumb. In 1838 William Joseph Curtis filed a British patent for a hydraulic jack. In 1851, inventor Richard Dudgeon was granted a patent for a "portable hydraulic press" - the hydraulic jack, a jack which proved to be vastly superior to the screw jacks in use at the time. Hydraulic jacks are used for shop work, rather than as an emergency jack to be carried with the vehicle. Use of jacks not designed for a specific vehicle requires more than the usual care in selecting ground conditions, the jacking point on a vehicle, to ensure stability when the jack is extended. Hydraulic jacks are used to lift elevators in low and medium rise buildings. A hydraulic jack uses a liquid, incompressible, forced into a cylinder by a pump plunger. Oil is used since it is self stable; when the plunger pulls back, it draws oil out of the reservoir through a suction check valve into the pump chamber. When the plunger moves forward, it pushes the oil through a discharge check valve into the cylinder.
The suction valve ball opens with each draw of the plunger. The discharge valve ball opens when the oil is pushed into the cylinder. At this point the suction ball within the chamber is forced shut and oil pressure builds in the cylinder. In a floor jack a horizontal piston pushes on the short end of a bellcrank, with the long arm providing the vertical motion to a lifting pad, kept horizontal with a horizontal linkage. Floor jacks include castors and wheels, allowing compensation for the arc taken by the lifting pad; this mechanism provides a low profile when collapsed, for easy maneuvering underneath the vehicle, while allowing considerable extension. A bottle jack or whiskey jack is a jack which resembles a bottle in shape, having a cylindrical body and a neck. Within is a vertical lifting ram with a support pad of some kind fixed to the top; the jack may work by screw action. In the hydraulic version the hydraulic ram emerges from the body vertically by hydraulic pressure provided by a pump either on the baseplate or at a remote location via a pressure hose.
With a single action piston the lift range is somewhat limited, so its use for lifting vehicles is limited to those with a high clearance. For lifting structures such as houses the hydraulic interconnection of multiple vertical jacks through valves enables the distribution of forces while enabling close control of the lift; the screw version of the bottle jack works by turning a large nut running on the threaded vertical ram at the neck of the body. The nut has gear teeth and is turned by a bevel gear spigotted to the body, the bevel gear being turned manually by a jack handle fitting into a square socket; the ram may have a second screwed ram within it. Bottle jacks may be used to lift a variety of objects. Typical uses include the repair of automobiles and house foundations. Larger, heavy-duty models may be known as a barrel jack; this type of jack is best used for short vertical lifts. Blocks may be used to repeat the operation. An air hydraulic jack is a hydraulic jack, actuated by compressed air - for example, air from a compressor - instead of human work.
This eliminates the need for the user to actuate the hydraulic mechanism, saving effort and i
Co-sleeping is a practice in which babies and young children sleep close to one or both parents, as opposed to in a separate room. Co-sleeping individuals sleep in sensory proximity to one another, where the individual senses the presence of others; this sensory proximity can either be triggered by touch, taste, or noise. Therefore, the individuals can be a few centimeters away or on the other side of the room and still have an effect on the other, it is standard practice in many parts of the world, is practiced by a significant minority in countries where cribs are used. Bed-sharing, a practice in which babies and young children sleep in the same bed with one or both parents, is a subset of co-sleeping. Co-bedding refers to infants sharing the same bed. There are conflicting views on bed-sharing safety and health compared to using a separate infant bed; the American Academy of Pediatrics does encourage room-sharing in its policy statement regarding SIDS prevention, but it recommends against bed-sharing with infants.
Recent legal rulings suggest that bed-sharing has been attributed as a factor of unintentional infant suffocation. For instance, parents under the influence of drugs or alcohol and whose children died while bed-sharing have been charged and, at times, prosecuted with manslaughter in several US states. Bed-sharing is standard practice in many parts of the world outside of North America and Australia, in the latter areas a significant minority of children have shared a bed with their parents at some point in childhood. One 2006 study of children age 3–10 in India reported 93% of children bed-sharing while a 2006 study of children in Kentucky in the United States reported 15% of infants and toddlers 2 weeks to 2 years engage in bed-sharing. Bed-sharing was practiced in all areas up to the 19th century, until the advent of giving the child his or her own room and the crib. In many parts of the world, bed-sharing has the practical benefit of keeping the child warm at night. Bed-sharing has been recently re-introduced into Western culture by practitioners of attachment parenting.
Proponents hold that bed-sharing saves babies' lives, promotes bonding, enables the parents to get more sleep and facilitates breastfeeding. Older babies can breastfeed during the night without waking their mother. Opponents argue, they cite concerns that a parent may smother the child or promote an unhealthy dependence of the child on the parent. In addition, they contend that this practice may interfere with the parents' own relationship, by reducing both communication and sexual intercourse at bedtime, argue that modern-day bedding is not safe for co-bedding; because children become accustomed to behaviors learned in early experiences, bed-sharing in infancy will increase the likelihood of these children to crawl into their parent's bed in ages past infancy. Health care professionals disagree about bed-sharing techniques and ethics; the U. S. Consumer Product Safety Commission and the American Academy of Pediatrics discourage bed-sharing because of the risk of suffocation or strangulation, but some pediatricians and breast-feeding advocates have opposed this position.
One study reported mothers getting more sleep and breast-feeding by co-sleeping than other arrangements. Parents experience less exhaustion with such ease in feeding and comforting their child by reaching over to the child; as a result, co-sleeping increases the responsiveness of parents to their child's needs. It has been argued that co-sleeping evolved over five million years, that it alters the infant's sleep experience and the number of maternal inspections of the infant, that it provides a beginning point for considering unconventional ways of helping reduce the risk of sudden infant death syndrome. Stress hormones are lower in mothers and babies who co-sleep the balance of the stress hormone cortisol, the control of, essential for a baby's healthy growth. In studies with animals, infants who stayed close to their mothers had higher levels of growth hormones and enzymes necessary for brain and heart growth; the physiology of co-sleeping babies is more stable, including more stable temperatures, more regular heart rhythms, fewer long pauses in breathing than babies who sleep alone.
Besides physical developmental advantages, co-sleeping may promote long-term emotional health. In long-term follow-up studies of infants who slept with their parents and those who slept alone, the children who co-slept were happier, less anxious, had higher self-esteem, were less to be afraid of sleep, had fewer behavioral problems, tended to be more comfortable with intimacy, were more independent as adults; some parents pose threats to infants due to their behaviors and conditions, such as smoking or drinking taking drugs, a history of skin infections, obesity, or any other specific risk-increasing traits. In addition, there are certain dangerous behaviors that increase SIDS and should be avoided whether placing a baby in a crib or co-sleeping: infants should always sleep on their backs on a firm surface, mattresses should intersect the bedframe there should be no stuffed animals or soft toys near the baby, blankets should be light, a baby's head should never be covered, other SIDS risk factors should be avoided.
Co-sleeping deaths in Texas reached at least 182 in the 2013-2014 fiscal year, which ends on August 31
Effect of spaceflight on the human body
Venturing into the environment of space can have negative effects on the human body. Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton. Other significant effects include a slowing of cardiovascular system functions, decreased production of red blood cells, balance disorders, eyesight disorders and changes in the immune system. Additional symptoms include fluid redistribution, loss of body mass, nasal congestion, sleep disturbance, excess flatulence; the engineering problems associated with leaving Earth and developing space propulsion systems have been examined for over a century, millions of man-hours of research have been spent on them. In recent years there has been an increase in research on the issue of how humans can survive and work in space for extended and indefinite periods of time; this question requires input from the physical and biological sciences and has now become the greatest challenge facing human space exploration.
A fundamental step in overcoming this challenge is trying to understand the effects and impact of long-term space travel on the human body. In October 2015, the NASA Office of Inspector General issued a health hazards report related to space exploration, including a human mission to Mars. On 12 April 2019, NASA reported medical results, from the Astronaut Twin Study, where one astronaut twin spent a year in space on the International Space Station, while the other twin spent the year on Earth, which demonstrated several long-lasting changes, including those related to alterations in DNA and cognition, when one twin was compared with the other. Many of the environmental conditions experienced by humans during spaceflight are different from those in which humans evolved; the immediate needs for breathable air and drinkable water are addressed by a life support system, a group of devices that allow human beings to survive in outer space. The life support system supplies air and food, it must maintain temperature and pressure within acceptable limits and deal with the body's waste products.
Shielding against harmful external influences such as radiation and micro-meteorites is necessary. Some hazards are difficult to mitigate, such as weightlessness defined as a microgravity environment. Living in this type of environment impacts the body in three important ways: loss of proprioception, changes in fluid distribution, deterioration of the musculoskeletal system. On 2 November 2017, scientists reported that significant changes in the position and structure of the brain have been found in astronauts who have taken trips in space, based on MRI studies. Astronauts who took longer space trips were associated with greater brain changes. In October 2018, NASA-funded researchers found that lengthy journeys into outer space, including travel to the planet Mars, may damage the gastrointestinal tissues of astronauts; the studies support earlier work that found such journeys could damage the brains of astronauts, age them prematurely. In March 2019, NASA reported that latent viruses in humans may be activated during space missions, adding more risk to astronauts in future deep-space missions.
Space medicine is a developing medical practice that studies the health of astronauts living in outer space. The main purpose of this academic pursuit is to discover how well and for how long people can survive the extreme conditions in space, how fast they can re-adapt to the Earth's environment after returning from space. Space medicine seeks to develop preventative and palliative measures to ease the suffering caused by living in an environment to which humans are not well adapted. During takeoff and reentry space travelers can experience several times normal gravity. An untrained person can withstand about 3g, but can blackout at 4 to 6g. G-force in the vertical direction is more difficult to tolerate than a force perpendicular to the spine because blood flows away from the brain and eyes. First the person experiences temporary loss of vision and at higher g-forces loses consciousness. G-force training and a G-suit which constricts the body to keep more blood in the head can mitigate the effects.
Most spacecraft are designed to keep g-forces within comfortable limits. The environment of space is lethal without appropriate protection: the greatest threat in the vacuum of space derives from the lack of oxygen and pressure, although temperature and radiation pose risks; the effects of space exposure can result in ebullism, hypoxia and decompression sickness. In addition to these, there is cellular mutation and destruction from high energy photons and sub-atomic particles that are present in the surroundings. Decompression is a serious concern during the extra-vehicular activities of astronauts. Current EMU designs take this and other issues into consideration, have evolved over time. A key challenge has been the competing interests of increasing astronaut mobility and minimising decompression risk. Investigators have considered pressurizing a separate head unit to the regular 71 kPa cabin pressure as opposed to the current whole-EMU pressure of 29.6 kPa. In such a design, pressurization of the torso could be achieved mechanically, avoiding mobility reduction associated with pneumatic pressurization.
Human physiology is adapted to living within the atmosphere of Earth
"Combat Sports" redirects here, for The Vaccines' album, see Combat Sports. A combat sport, or fighting sport, is a competitive contact sport that involves one-on-one combat. In many combat sports, a contestant wins by scoring more points than the opponent or by disabling the opponent. Common combat sports include mixed martial arts, wrestling, savate, Muay Thai, Tae Kwon Do, Brazilian Jiu-jitsu, HMB, Kyokushin, Kūdō, sometimes Ninjutsu. Tradition styles of wrestling exist in most cultures. Boxing contests date back to ancient Sumer in the 3rd millennium BCE and ancient Egypt circa 1350 BCE; the ancient Olympic Games included several combat-related sports: armored foot races, boxing and pankration, introduced in the Olympic Games of 648 BCE. In ancient China, combat sport appeared in the form of lei tai, it was a no-holds barred combat sport that combined wrestling. There is evidence of similar combat sports in ancient Egypt and Japan. Through the Middle ages and Renaissance, the tournament was popular.
Tournaments were competitions that featured several mock combat events, with jousting as a main event. While the tournament was popular among aristocrats, combat sports were practiced by all levels of society; the German school of late medieval martial arts distinguished sportive combat from serious combat. In the German Renaissance, sportive combat competitions were known as Fechtschulen, corresponding to the Prize Playing in Tudor England. Out of these Prize Playing events developed the English boxing of the 18th century, which evolved into modern boxing with the introduction of the Marquess of Queensberry rules in 1867. Amateur boxing has been part of the modern Olympic Games since their introduction in 1904. Professional boxing became popular in the United States in the 1920s and experienced a "golden age" after World War II; the creation of Brazilian Jiu-Jitsu is attributed to the Gracie family of Brazil in 1925 after Asian martial arts were introduced to Brazil. Vale-tudo, muay thai kickboxing and luta livre gained popularity.
Modern Muay Thai was developed in the 1920s to 1930s. Sambo was introduced in the Soviet Union. Modern Taekwondo emerged after the Japanese occupation of Korea and became an Olympic sport in 2000. Sanshou as part of modern wushu was developed in the People's Republic of China since the 1950s. Kickboxing and full contact karate were developed in the 1960s and became popular in Japan and the West during the 1980s and 1990s. Modern Mixed Martial Arts developed out of the interconnected subcultures of Brazilian Jiu-Jitsu and shoot wrestling, it was introduced in Japan in the form of Shooto in 1985, in the United States as Ultimate Fighting Championship in 1993. The Unified Rules of Mixed Martial Arts were introduced in 2000, the sport experienced peak popularity in the 2000s. During this period, multiple brands and promotions were established; the most well-known promotion for MMA is UFC. Combat sports are more popular among men, both as athletes and as spectators. For many years, participation in combat sports was exclusive to men.
A study conducted by Greenwell, Hancock and Thorn in 2015 revealed that combat sports had a male audience. Combat sport promotions such as UFC or Bellator MMA are advertised to men. Combat athletes fight one-on-one. Different sports moves. For example, boxing only allows punches, taekwondo involves kicks, both Muay Thai and Burmese boxing allow the use of elbows and knees. There are combat sports based on grappling, such as both freestyle and Collegiate wrestling. Modern MMA is similar to the ancient Greek Olympic sport of pankration; some combat sports involve the use of weapons and armor, such as fencing and the new sport SCA Heavy Combat. Boxing Historical Ancient Greek boxing Historical Russian Fist Fighting Historical English Bare-Knuckle Boxing Modern Amateur Boxing Modern Professional Boxing Kickboxing and analogous styles Musti-yuddha Savate Sanda Indochinese Kickboxing Muay Thai Muay Lao Lethwei Shoot boxing Japanese combat sport introduced in 1985. Karate Full Contact Karate Taekwondo Pinning and takedown oriented wrestling Ancient Greek wrestling Beach wrestling Belt wrestling Judo Freestyle wrestling Greco-Roman wrestling Scholastic wrestling Sport Sambo Sumo Submission grappling: Brazilian Jiu-Jitsu luta livre FILA Grappling Folk wrestling shuai jiao Catch wrestling Hybrid martial arts, combining striking and grappling elements: Pankration.
Modern Amateur Pankration Dambe traditional form of boxing, including kicking and wrestling elements, practiced by the Hausa people. Combat Sambo: Russian sport introduced in the 1920s. Kudo Vale Tudo, derived from Brazilian circus shows of the 1920s. Sanshou, institutionalized as part of modern Wushu since the 1950s. Shoot-style wrestling, since the 1980s. Shootfighting Shoot boxing Japanese combat sp
Burke and Hare murders
The Burke and Hare murders were a series of 16 killings committed over a period of about ten months in 1828 in Edinburgh, Scotland. They were undertaken by William Burke and William Hare, who sold the corpses to Robert Knox for dissection at his anatomy lectures. Edinburgh was a leading European centre of anatomical study in the early 19th century, in a time when the demand for cadavers led to a shortfall in legal supply. Scottish law required that corpses used for medical research should only come from those who had died in prison, suicide victims, or from foundlings and orphans; the shortage of corpses led to an increase in body snatching by what were known as "resurrection men". Measures to ensure graves were left undisturbed exacerbated the shortage; when a lodger in Hare's house died, Hare turned to his friend Burke for advice and they decided to sell the body to Knox. They received. A little over two months when Hare was concerned that a lodger suffering from fever would deter others from staying in the house, he and Burke murdered her and sold the body to Knox.
The men continued their murder spree with the knowledge of their wives. Burke and Hare's actions were uncovered after other lodgers discovered their last victim, Margaret Docherty, contacted the police. A forensic examination of Docherty's body indicated she had been suffocated, but this could not be proven. Although the police suspected Burke and Hare of other murders, there was no evidence on which they could take action. An offer was put to Hare granting immunity from prosecution, he confessed to all 16 deaths. At the subsequent trial Burke was sentenced to death; the case against his wife was found not proven—a Scottish legal verdict to acquit an individual but not declare them innocent. Burke was hanged shortly afterwards; the murders raised public awareness of the need for bodies for medical research and contributed to the passing of the Anatomy Act 1832. The events have made appearances in literature, been portrayed on screen, either in fictionalised accounts or as the inspiration for fictional works.
In the early 19th century Edinburgh had several pioneering anatomy teachers, including Alexander Monro, his son, called Alexander, John Bell, John Goodsir and Robert Knox, all of whom developed the subject into a modern science. Because of their efforts, Edinburgh became one of the leading European centres of anatomical study, alongside Leiden in the Netherlands and the Italian city of Padua; the teaching of anatomy—crucial in the study of surgery—required a sufficient supply of cadavers, the demand for which increased as the science developed. Scottish law determined that suitable corpses on which to undertake the dissections were those who died in prison, suicide victims, the bodies of foundlings and orphans. With the rise in prestige and popularity of medical training in Edinburgh, the legal supply of corpses failed to keep pace with the demand; the situation was confused by the legal position. Disturbing a grave was a criminal offence, as was the taking of property from the deceased. Stealing the body was not an offence, as it did not belong to anyone.
The price per corpse changed depending on the season. It was £8 during the summer, when the warmer temperatures brought on quicker decomposition, £10 in the winter months, when the demand by anatomists was greater, because the colder temperatures meant they could store corpses longer so they undertook more dissections. By the 1820s the residents of Edinburgh had taken to the streets to protest at the increase in grave robbing. To avoid corpses being disinterred, bereaved families used several techniques in order to deter the thieves: guards were hired to watch the graves, watchtowers were built in several cemeteries. Other families used an iron cage that surrounded the coffin; the high levels of vigilance from the public, the techniques used to deter the grave robbers, led to what the historian Ruth Richardson describes as "a growing atmosphere of crisis" among anatomists because of the shortage of corpses. The historian Tim Marshall considers the situation meant "Burke and Hare took graverobbing to its logical conclusion: instead of digging up the dead, they accepted lucrative incentives to destroy the living".
Knox was an anatomist who had qualified as a doctor in 1814. After contracting smallpox as a child, he was badly disfigured, he undertook service as an army physician at the Battle of Waterloo in 1815, followed by a posting in England and during the Cape Frontier War, in southern Africa. He settled in his home town of Edinburgh in 1820. In 1825 he became a fellow of the Royal College of Surgeons of Edinburgh, where he lectured on anatomy, he undertook dissections twice a day, his advertising promised "a full demonstration on fresh anatomical subjects" as part of every course of lectures he delivered. Clare Taylor, his biographer in the Dictionary of National Biography, observes that he "built up a formidable reputation as a teacher and lecturer and single-handedly raised the profile of the study of anatomy in Britain". Another biograp