Boyle's law referred to as the Boyle–Mariotte law, or Mariotte's law, is an experimental gas law that describes how the pressure of a gas tends to increase as the volume of the container decreases. A modern statement of Boyle's law is: The absolute pressure exerted by a given mass of an ideal gas is inversely proportional to the volume it occupies if the temperature and amount of gas remain unchanged within a closed system. Mathematically, Boyle's law can be stated as: or where P is the pressure of the gas, V is the volume of the gas, k is a constant; the equation states that the product of pressure and volume is a constant for a given mass of confined gas and this holds as long as the temperature is constant. For comparing the same substance under two different sets of conditions, the law can be usefully expressed as: P 1 V 1 = P 2 V 2.. This equation shows; as volume decreases, the pressure of the gas increases. The law was named after chemist and physicist Robert Boyle, who published the original law in 1662.

This relationship between pressure and volume was first noted by Richard Towneley and Henry Power in the 17th century. Robert Boyle published the results. According to Robert Gunther and other authorities, it was Boyle's assistant, Robert Hooke, who built the experimental apparatus. Boyle's law is based on experiments with air, which he considered to be a fluid of particles at rest in between small invisible springs. At that time, air was still seen as one of the four elements. Boyle's interest was to understand air as an essential element of life. Boyle used a closed J-shaped tube and after pouring mercury from one side he forced the air on the other side to contract under the pressure of mercury. After repeating the experiment several times and using different amounts of mercury he found that under controlled conditions, the pressure of a gas is inversely proportional to the volume occupied by it; the French physicist Edme Mariotte discovered the same law independently of Boyle in 1679, but Boyle had published it in 1662.

Mariotte did, discover that air volume changes with temperature. Thus this law is sometimes referred to as the Boyle -- Mariotte law. In 1687 in the Philosophiæ Naturalis Principia Mathematica, Newton showed mathematically that in an elastic fluid consisting of particles at rest, between which are repulsive forces inversely proportional to their distance, the density would be directly proportional to the pressure, but this mathematical treatise is not the physical explanation for the observed relationship. Instead of a static theory, a kinetic theory is needed, provided two centuries by Maxwell and Boltzmann; this law was the first physical law to be expressed in the form of an equation describing the dependence of two variable quantities. The law itself can be stated as follows: For a fixed mass of an ideal gas kept at a fixed temperature and volume are inversely proportional. Or Boyle's law is a gas law, stating that the pressure and volume of a gas have an inverse relationship. If volume increases pressure decreases and vice versa, when temperature is held constant.

Therefore, when the volume is halved, the pressure is doubled. Boyle's law states that at constant temperature the volume of a given mass of a dry gas is inversely proportional to its pressure. Most gases behave like ideal gases at moderate temperatures; the technology of the 17th century could not produce high pressures or low temperatures. Hence, the law was not to have deviations at the time of publication; as improvements in technology permitted higher pressures and lower temperatures, deviations from the ideal gas behavior became noticeable, the relationship between pressure and volume can only be described employing real gas theory. The deviation is expressed as the compressibility factor. Boyle derived the law by experiment; the law can be derived theoretically based on the presumed existence of atoms and molecules and assumptions about motion and elastic collisions. These assumptions were met with enormous resistance in the positivist scientific community at the time however, as they were seen as purely theoretical constructs for which there was not the slightest observational evidence.

Daniel Bernoulli derived Boyle's law by applying Newton's laws of motion at the molecular level. It remained ignored until around 1845, when John Waterston published a paper building the main precepts of kinetic theory. Works of James Prescott Joule, Rudolf Clausius and in particular Ludwig Boltzmann established the kinetic theory of gases and brought attention to both the theories of Bernoulli and Waterston; the debate between proponents of energetics and atomism led Boltzmann to write a book in 1898, which endured criticism until his suicide in 1906. Albert Einstein in 1905 showed how kinetic theory applies to the Brownian motion of a fluid-suspended particle, confirmed in 1908 by Jean Perrin; the mathematical equation for Boyle's law is: P V = k where: P denotes the pressure of the system. V denotes the volume of the gas. K is a constant value representative of the temperature and volume of the syst

The Volunteer Reserves are the British Armed Forces voluntary and part-time military reserve force. Unlike the Regular Reserve, the Volunteer Reserves do not consist of ex-Regular personnel who remain liable to be re-called for military service. Instead, the Volunteer Reserves consists of civilian volunteers who undergo training and military operations alongside the Regular military; the Volunteer Reserves serve under a fixed-term reserve contract and provide "highly trained" military personnel integrated with their Regular counterparts, on operations both at home and overseas. For example every major military operation has seen the deployment of Army Reservists alongside the Regular British Army. Volunteer Reserves are allowed to use the post-nominal letters VR after 10 years of service; the Volunteer Reserves includes the armed forces University Service Units. These training units are not liable for military service, they provide engagement and military training for undergraduate students at UK universities.

The Volunteer Reserves consist of four elements, each being an integrated part of their parent service and liable for military operations. University Training Units are listed with their parent organization: Army Reserve – Maritime_Reserve_ Royal Naval Reserve – Royal Marines Reserve Royal Auxiliary Air ForceIn addition: As part of the "Future Reserves 2020" review conducted in 2012, the Volunteer Reserves will be integrated with the Regular Armed Forces and better prepared for overseas deployments and operations. Regular Reserve Reserve Forces and Cadets Association Maritime Reserve - a term used for the grouping together of the Royal Naval and Royal Marines Reserve Reserve Forces Act 1996 Sponsored Reserves The Offfice S:1 E:2 gov.uk MoD – reserves and cadet strengths, April 2014

The Baby-Roast known as The Hippy Babysitter and The Cooked Baby, is an urban legend in which a baby is roasted alive at home during the absence of a parent. The Straight Dope, a newspaper column devoted to exposing myths, reported that it "is one of the classic urban legends", there have been real life instances where babies have been roasted. In some versions, the baby is accidentally cooked. For example, "put the turkey in the oven and the baby in the bed" is wrongly heard as "put the baby in the oven and the turkey in the bed". Other variants set out that the doer of the deed was drug or alcohol-induced or an insane individual. In the end, the roasted baby is sometimes served as food to be consumed by the parents; the person who roasts the baby is a babysitter or the baby's sibling. In real life, there have been documented occurrences of babies being roasted, though by family members instead of strange babysitters; when Virginian Elizabeth Renee Otte roasted her baby in 1999, the incident was cited as causing the legend to become true.

In November 2006, a second case of real-life baby-roasting was reported. In May 2012, a British citizen was arrested by Thai police after being found in possession of six corpses of roasted infants, some wrapped in gold leaf in conformity with a "black magic ritual". On November 16, 2015, a one-year old baby, J'Zyra Thompson, died after her three-year-old sibling put her in the oven and cooked her alive, their mother, Racqual Thompson, left her four kids at home, which included a five-year-old and a two-year-old, when she went to pick up a pizza. When they returned home, Thompson found J'Zyra's body cooked in the oven. Thompson and her boyfriend of ten months, 21-year-old Cornell Malone, were charged with endangering a child and are awaiting trial. In March 2016, a 35-year-old mother in Texas showed up naked at her neighbor's door with her burned and naked 2-year-old daughter; when police arrived, she confessed that she had put the girl in the oven along with a cat she had shot dead, while making sexual advances toward an officer and singing praise to God.

According to an affidavit from the Texas Department of Family and Protective Services, she seemed unconcerned with her daughter while in hospital and jail, where she was charged with injury to a child with serious bodily injury and tested positive for alcohol and methamphetamine. The girl was put in foster care. In the 1979 blaxploitation film Avenging Disco Godfather, a PCP addict claims to have honey-roasted her baby for her family's Easter dinner, ostensibly so the baby's crying wouldn't spoil the occasion. In the thirteenth episode of Teen Girl Squad, released on June 18, 2007, the main cast of teenage girls is babysitting the infant Tomkins; when What's-Her-Face attempts to drink a can of diet soda, So-And-So loudly objects and - citing a blatantly-labelled book of urban legends from health class - claims that drinking it will make her "microwave the baby!" What's-Her-Face is quick to correct her that the diet soda is not PCP. In August 2009, a joke advertisement showcasing a "body part roaster" "specially designed to roast infants and other human morsels" surfaced on the website of retailer Sears.com.

The song'Babysitter on Acid' by the all-female punk rock band, Lunachicks is a retelling of the Urban Legend. The teenage babysitter, under the influence of drugs, roasts the baby in the oven and tells the mother over the phone that "Wanna know how the baby is? / Don't worry, she's done". The song was released on their 1990 album Babysitters On Acid. Atreus