Poynting
Poynting may refer to: * John Henry Poynting (1852–1914), a British physicist, after whom are named: ** Poynting vector, a representation of the energy flux of an electromagnetic field ** Poynting's theorem on conservation of energy in electromagnetic field ** Poynting (lunar crater), crater on the Moon ** Poynting (Martian crater), crater on Mars ** 11063 Poynting, a main-belt asteroid See also * Pointing, a gesture * Pointing (other) Pointing may refer to: * Pointing, the hand gesture ** Pointing, a hand signal in the sport of pickleball indicating the ball is out * Ostensive definition * Pointing, the external part of the mortar between bricks in walling (see repointing) * Po ...

Poynting Vector
In physics, the Poynting vector (or Umov–Poynting vector) represents the directional energy flux (the energy transfer per unit area, per unit time) or '' power flow'' of an electromagnetic field. The SI unit of the Poynting vector is the watt per square metre (W/m2); kg/s3 in SI base units. It is named after its discoverer John Henry Poynting who first derived it in 1884. Nikolay Umov is also credited with formulating the concept. Oliver Heaviside also discovered it independently in the more general form that recognises the freedom of adding the curl of an arbitrary vector field to the definition. The Poynting vector is used throughout electromagnetics in conjunction with Poynting's theorem, the continuity equation expressing conservation of electromagnetic energy, to calculate the power flow in electromagnetic fields. Definition In Poynting's original paper and in most textbooks, the Poynting vector \mathbf is defined as the cross product \mathbf = \mathbf \time ...
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John Henry Poynting
John Henry Poynting Fellow of the Royal Society, FRS (9 September 185230 March 1914) was an English physicist. He was the first professor of physics at Mason Science College from 1880 to 1900, and then the successor institution, the University of Birmingham until his death. Early life and education Poynting was the youngest son of Thomas Elford Poynting, a Unitarianism, Unitarian minister. He was born at the parsonage of the Monton Unitarian Chapel in Eccles, Lancashire, where his father served as minister from 1846 to 1878. In his boyhood, he was educated at the nearby school operated by his father. From 1867 to 1872, he attended Owens College, now the University of Manchester, where his physics teachers included Osborne Reynolds and Balfour Stewart. From 1872 to 1876 he was a student at the University of Cambridge, where he attained high honours in mathematics after taking grinds with Edward Routh. Career In the late 1870s, he worked in the Cavendish Laboratory at Cambridge ...
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Poynting's Theorem
In electrodynamics, Poynting's theorem is a statement of conservation of energy for electromagnetic fields that was developed by British physicist John Henry Poynting. It states that in a given volume, the stored energy changes at a rate given by the work done on the charges within the volume, minus the rate at which energy leaves the volume. It is only strictly true in media that is not dispersive, but can be extended for the dispersive case. The theorem is analogous to the work-energy theorem in classical mechanics, and mathematically similar to the continuity equation. Definition Poynting's theorem states that the rate of energy transfer per unit volume from a region of space equals the rate of work done on the charge distribution in the region, plus the energy flux leaving that region. Mathematically: where: * -\frac is the rate of change of the energy density in the volume. * ∇ ⋅ S is the energy flow out of the volume, given by the divergence of the Poynting vect ...
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Poynting (lunar Crater)
Poynting is a large Lunar craters, lunar impact crater located on the Far side (Moon), far side of the Moon. It is located to the north-northwest of the walled plain Hertzsprung (crater), Hertzsprung, with the crater Fersman (crater), Fersman immediately to the east and Kekulé (crater), Kekulé equally near to the west-southwest. This crater has undergone some erosion, and several small craters lie across the rim and inner wall. A pair of these lie next to each other along the eastern side, and another pair on the western rim. Across the southeast rim is a nearly merged crater pair. Parts of the rim remain well-defined, however, including the east and north where there are some wiktionary:terrace, terraces. The rim is generally circular, with a slight inward intrusion along the northwest. The interior floor is relatively level, except for a central peak ridge located slightly to the east of the midpoint. There are small craterlets on the floor near the south and northwest edge ...
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Poynting (Martian Crater)
Poynting may refer to: * John Henry Poynting (1852–1914), a British physicist, after whom are named: ** Poynting vector, a representation of the energy flux of an electromagnetic field ** Poynting's theorem on conservation of energy in electromagnetic field ** Poynting (lunar crater), crater on the Moon ** Poynting (Martian crater), crater on Mars ** 11063 Poynting, a main-belt asteroid See also * Pointing, a gesture * Pointing (other) Pointing may refer to: * Pointing, the hand gesture ** Pointing, a hand signal in the sport of pickleball indicating the ball is out * Ostensive definition * Pointing, the external part of the mortar between bricks in walling (see repointing) * Po ...

11063 Poynting
Eleven or 11 may refer to: *11 (number) * One of the years 11 BC, AD 11, 1911, 2011 Literature * ''Eleven'' (novel), a 2006 novel by British author David Llewellyn *''Eleven'', a 1970 collection of short stories by Patricia Highsmith *''Eleven'', a 2004 children's novel in The Winnie Years by Lauren Myracle *''Eleven'', a 2008 children's novel by Patricia Reilly Giff *''Eleven'', a short story by Sandra Cisneros Music *Eleven (band), an American rock band * Eleven: A Music Company, an Australian record label *Up to eleven, an idiom from popular culture, coined in the movie ''This Is Spinal Tap'' Albums * ''11'' (The Smithereens album), 1989 * ''11'' (Ua album), 1996 * ''11'' (Bryan Adams album), 2008 * ''11'' (Sault album), 2022 * ''Eleven'' (Harry Connick, Jr. album), 1992 * ''Eleven'' (22-Pistepirkko album), 1998 * ''Eleven'' (Sugarcult album), 1999 * ''Eleven'' (B'z album), 2000 * ''Eleven'' (Reamonn album), 2010 * ''Eleven'' (Martina McBride album), 2011 * ''Eleven'' (Mr Fogg ...
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Pointing
Pointing is a gesture specifying a direction from a person's body, usually indicating a location, person, event, thing or idea. It typically is formed by extending the arm, hand, and index finger, although it may be functionally similar to other hand gestures. Types of pointing may be subdivided according to the intention of the person, as well as by the linguistic function it serves. Pointing typically develops within the first two years of life in humans, and plays an important role in language development and reading in children. It is central to the use of sign language, with a large number of signs being some variation on pointing. The nature of pointing may differ for children who have autism or who are deaf, and may also vary by gender. It is typically not observed in children who are blind from birth. Pointing may vary substantially across cultures, with some having many distinct types of pointing, both with regard to the physical gestures employed and their interpret ...
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