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James Sayers (physicist)
James Sayers (2 September 1912 – 13 March 1993) was a Northern Irish physicist who played a crucial role in developing centimetric radar, which is now used in microwave ovens. Early life He was born on a farm in Corkey, County Antrim, Ireland. He built a water wheel to provide the farm with electricity. He attended Ballymena Academy. He obtained an MSc at Queen's University Belfast, then attended St John's College, Cambridge gaining a PhD. Career From 1939 to 1943 he conducted research for the Admiralty at the University of Birmingham on centrimetric radar, producing the cavity magnetron. He worked with John Randall and Harry Boot. From 1943 to 1945 he was part of a group of British scientists that worked on the Manhattan Project. From 1946 until 1972 he was Professor of Electron Physics at the University of Birmingham. Sayers was responsible for electron density experiments using data gathered by the French satellite FR-1 The Ryan FR Fireball was an Amer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centimetric Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. The t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Density
In quantum chemistry, electron density or electronic density is the measure of the probability of an electron being present at an infinitesimal element of space surrounding any given point. It is a scalar quantity depending upon three spatial variables and is typically denoted as either \rho(\textbf r) or n(\textbf r). The density is determined, through definition, by the normalised N-electron wavefunction which itself depends upon 4N variables (3N spatial and N spin coordinates). Conversely, the density determines the wave function modulo up to a phase factor, providing the formal foundation of density functional theory. According to quantum mechanics, due to the uncertainty principle on an atomic scale the exact location of an electron cannot be predicted, only the probability of its being at a given position; therefore electrons in atoms and molecules act as if they are "smeared out" in space. For one-electron systems, the electron density at any point is proportional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1993 Deaths
File:1993 Events Collage.png, From left, clockwise: The Oslo I Accord is signed in an attempt to resolve the Israeli–Palestinian conflict; The White House (Moscow), Russian White House is shelled during the 1993 Russian constitutional crisis; Czechoslovakia is peacefully Dissolution of Czechoslovakia, dissolved into the Czech Republic and Slovakia; In the United States, the ATF Waco siege, besieges a compound belonging to David Koresh and the Branch Davidians in a search for illegal weapons, which ends in the building being set alight and killing most inside; Eritrea gains independence; A major 1993 Storm of the Century, snow storm passes over the United States and Canada, leading to over 300 fatalities; Drug lord and narcoterrorism, narcoterrorist Pablo Escobar is killed by Military Forces of Colombia, Colombian special forces; Ramzi Yousef and other Islamic terrorism, Islamic terrorists 1993 World Trade Center bombing, detonate a truck bomb in the subterranean garage of List of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alumni Of St John's College, Cambridge
Alumni (singular: alumnus (masculine) or alumna (feminine)) are former students of a school, college, or university who have either attended or graduated in some fashion from the institution. The feminine plural alumnae is sometimes used for groups of women. The word is Latin and means "one who is being (or has been) nourished". The term is not synonymous with "graduate"; one can be an alumnus without graduating ( Burt Reynolds, alumnus but not graduate of Florida State, is an example). The term is sometimes used to refer to a former employee or member of an organization, contributor, or inmate. Etymology The Latin noun ''alumnus'' means "foster son" or "pupil". It is derived from PIE ''*h₂el-'' (grow, nourish), and it is a variant of the Latin verb ''alere'' "to nourish".Merriam-Webster: alumnus .. Separate, but from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People From Ballymena
A person ( : people) is a being that has certain capacities or attributes such as reason, morality, consciousness or self-consciousness, and being a part of a culturally established form of social relations such as kinship, ownership of property, or legal responsibility. The defining features of personhood and, consequently, what makes a person count as a person, differ widely among cultures and contexts. In addition to the question of personhood, of what makes a being count as a person to begin with, there are further questions about personal identity and self: both about what makes any particular person that particular person instead of another, and about what makes a person at one time the same person as they were or will be at another time despite any intervening changes. The plural form "people" is often used to refer to an entire nation or ethnic group (as in "a people"), and this was the original meaning of the word; it subsequently acquired its use as a plural form of per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physicists From Northern Ireland
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate causes of phenomena, and usually frame their understanding in mathematical terms. Physicists work across a wide range of research fields, spanning all length scales: from sub-atomic and particle physics, through biological physics, to cosmological length scales encompassing the universe as a whole. The field generally includes two types of physicists: experimental physicists who specialize in the observation of natural phenomena and the development and analysis of experiments, and theoretical physicists who specialize in mathematical modeling of physical systems to rationalize, explain and predict natural phenomena. Physicists can apply their knowledge towards solving practical problems or to developing new technologies (also known as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhattan Project People
Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state of New York. Located near the southern tip of New York State, Manhattan is based in the Eastern Time Zone and constitutes both the geographical and demographic center of the Northeast megalopolis and the urban core of the New York metropolitan area, the largest metropolitan area in the world by urban landmass. Over 58 million people live within 250 miles of Manhattan, which serves as New York City’s economic and administrative center, cultural identifier, and the city’s historical birthplace. Manhattan has been described as the cultural, financial, media, and entertainment capital of the world, is considered a safe haven for global real estate investors, and hosts the United Nations headquarters. New York City is the headquarters of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Servants In The Admiralty
{{disambiguation ...
Civil may refer to: *Civic virtue, or civility *Civil action, or lawsuit * Civil affairs *Civil and political rights *Civil disobedience *Civil engineering *Civil (journalism), a platform for independent journalism *Civilian, someone not a member of armed forces *Civil law (other), multiple meanings *Civil liberties *Civil religion *Civil service *Civil society *Civil war *Civil (surname) Civil is a surname. Notable people with the surname include: *Alan Civil (1929–1989), British horn player *François Civil (born 1989), French actor * Gabrielle Civil, American performance artist *Karen Civil (born 1984), American social media an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Members Of HM Scientific Civil Service
Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science), entries in a database ** Member variable, a variable that is associated with a specific object * Limb (anatomy), an appendage of the human or animal body ** Euphemism for penis * Structural component of a truss, connected by nodes * User (computing), a person making use of a computing service, especially on the Internet * Member (geology), a component of a geological formation * Member of parliament * The Members, a British punk rock band * Meronymy, a semantic relationship in linguistics * Church membership, belonging to a local Christian congregation, a Christian denomination and the universal Church * Member, a participant in a club or learned society A learned society (; also learned academy, scholarly society, or academic association) is an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Pioneers
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Worcestershire
Worcestershire ( , ; written abbreviation: Worcs) is a county in the West Midlands of England. The area that is now Worcestershire was absorbed into the unified Kingdom of England in 927, at which time it was constituted as a county (see History of Worcestershire). Over the centuries the county borders have been modified, but it was not until 1844 that substantial changes were made. Worcestershire was abolished as part of local government reforms in 1974, with its northern area becoming part of the West Midlands and the rest part of the county of Hereford and Worcester. In 1998 the county of Hereford and Worcester was abolished and Worcestershire was reconstituted, again without the West Midlands area. Location The county borders Herefordshire to the west, Shropshire to the north-west, Staffordshire only just to the north, West Midlands to the north and north-east, Warwickshire to the east and Gloucestershire to the south. The western border with Herefordshire incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alvechurch
Alvechurch ( ) is a large village and civil parish in the Bromsgrove district in northeast Worcestershire, England, in the valley of the River Arrow. The Lickey Hills Country Park is 2.5 miles (4 km) to the northwest. It is south of Birmingham, north of Redditch and east of Bromsgrove. At the 2001 Census, the population was 5,316. History Alvechurch means "Ælfgyth's church". In the eighth century, Ælfgyth founded a church on the site of the church of St. Laurence. King Offa of Mercia gave the land forming the parish to Bishops of Worcester in 780. The parish is mentioned in the Domesday Book of 1068 as ''Alvievecherche'' with a small population of under 20 people. In the 13th Century the Bishop of Worcester built a palace in the village, and a weekly market and an annual fair were established. The Bishop's Palace was pulled down in the 17th century, the only remnants being part of the moat and a yew tree which formerly stood in the palace grounds. From the 19th c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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