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Brandon Carter
Brandon Carter, (born 1942) is an Australian theoretical physicist, best known for his work on the properties of black holes and for being the first to name and employ the anthropic principle in its contemporary form. He is a researcher at the Meudon campus of the Laboratoire Univers et Théories, part of the CNRS. Biography Carter studied at the University of Cambridge under Dennis Sciama. He found the exact solution of the geodesic equations for the Kerr/Newman electrovacuum solution, and the maximal analytic extension of this solution. In the process, he discovered the extraordinary ''fourth constant of motion'' and the Killing–Yano tensor. Together with Werner Israel and Stephen Hawking, he proved partially the no-hair theorem in general relativity, stating that all stationary black holes are completely characterized by mass, charge, and angular momentum. In 1982 with astrophysicist Jean-Pierre Luminet, he invented the concept of tidal disruption event (TDE), name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the ' is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations. Newton's law of universal gravitation, which describes classical gravity, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass distributions. Some predictions of general relativity, however, are beyond Newton's law of universal gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French National Centre For Scientific Research Scientists
French (french: français(e), link=no) may refer to: * Something of, from, or related to France ** French language, which originated in France, and its various dialects and accents ** French people, a nation and ethnic group identified with France ** French cuisine, cooking traditions and practices Fortnite French places Arts and media * The French (band), a British rock band * "French" (episode), a live-action episode of ''The Super Mario Bros. Super Show!'' * ''Française'' (film), 2008 * French Stewart (born 1964), American actor Other uses * French (surname), a surname (including a list of people with the name) * French (tunic), a particular type of military jacket or tunic used in the Russian Empire and Soviet Union * French's, an American brand of mustard condiment * French catheter scale, a unit of measurement of diameter * French Defence, a chess opening * French kiss, a type of kiss involving the tongue See also * France (other) * Franch, a surname * Frenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
21st-century Australian Physicists
The 1st century was the century spanning AD 1 ( I) through AD 100 ( C) according to the Julian calendar. It is often written as the or to distinguish it from the 1st century BC (or BCE) which preceded it. The 1st century is considered part of the Classical era, epoch, or historical period. The 1st century also saw the appearance of Christianity. During this period, Europe, North Africa and the Near East fell under increasing domination by the Roman Empire, which continued expanding, most notably conquering Britain under the emperor Claudius (AD 43). The reforms introduced by Augustus during his long reign stabilized the empire after the turmoil of the previous century's civil wars. Later in the century the Julio-Claudian dynasty, which had been founded by Augustus, came to an end with the suicide of Nero in AD 68. There followed the famous Year of Four Emperors, a brief period of civil war and instability, which was finally brought to an end by Vespasian, ninth Roman emperor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1942 Births
Year 194 ( CXCIV) was a common year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Septimius and Septimius (or, less frequently, year 947 ''Ab urbe condita''). The denomination 194 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Emperor Septimius Severus and Decimus Clodius Septimius Albinus Caesar become Roman Consuls. * Battle of Issus: Septimius Severus marches with his army (12 legions) to Cilicia, and defeats Pescennius Niger, Roman governor of Syria. Pescennius retreats to Antioch, and is executed by Severus' troops. * Septimius Severus besieges Byzantium (194–196); the city walls suffer extensive damage. Asia * Battle of Yan Province: Warlords Cao Cao and Lü Bu fight for control over Yan Province; the battle lasts for over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Star
A neutron star is the collapsed core of a massive supergiant star, which had a total mass of between 10 and 25 solar masses, possibly more if the star was especially metal-rich. Except for black holes and some hypothetical objects (e.g. white holes, quark stars, and strange stars), neutron stars are the smallest and densest currently known class of stellar objects. Neutron stars have a radius on the order of and a mass of about 1.4 solar masses. They result from the supernova explosion of a massive star, combined with gravitational collapse, that compresses the core past white dwarf star density to that of atomic nuclei. Once formed, they no longer actively generate heat, and cool over time; however, they may still evolve further through collision or accretion. Most of the basic models for these objects imply that neutron stars are composed almost entirely of neutrons (subatomic particles with no net electrical charge and with slightly larger mass than protons); ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tidal Disruption Event
A tidal disruption event (TDE) is an astronomical phenomenon that occurs when a star approaches sufficiently close to a supermassive black hole (SMBH) to be pulled apart by the black hole's tidal force, experiencing spaghettification. A portion of the star's mass can be captured into an accretion disk around the black hole (if the star is on a parabolic orbit), resulting in a temporary flare of electromagnetic radiation as matter in the disk is consumed by the black hole. According to early papers, tidal disruption events should be an inevitable consequence of massive black holes' activity hidden in galaxy nuclei, whereas later theorists concluded that the resulting explosion or flare of radiation from the accretion of the stellar debris could be a unique signpost for the presence of a dormant black hole in the center of a normal galaxy. Sometimes a star can survive the encounter with an SMBH, and a remnant is formed. These events are termed partial TDEs. History Physicist Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jean-Pierre Luminet
Jean-Pierre Luminet (born 3 June 1951) is a French astrophysicist, specializing in black holes and cosmology. He is an emeritus research director at the CNRS (Centre national de la recherche scientifique). Luminet is a member of the Laboratoire d'Astrophysique de Marseille (LAM) and Laboratoire Univers et Théories (LUTH) of the Paris-Meudon Observatory, and is a visiting scientist at the Centre de Physique Théorique (CPT) in Marseilles. He is also a writer and poet. Luminet has been awarded several prizes on account of his work in pure science and science communication, including the Georges Lemaître Prize (1999) in recognition of his work in cosmology. In November 2021, he received the UNESCO Kalinga Prize for the Popularization of Science. He serves on the editorial board of ''Inference: The International Review of Science''. The asteroid 5523 Luminet, discovered in 1991 at Palomar Observatory, was named after him. Luminet has published fifteen science books, seven histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Momentum
In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational analog of linear momentum. It is an important physical quantity because it is a conserved quantity—the total angular momentum of a closed system remains constant. Angular momentum has both a direction and a magnitude, and both are conserved. Bicycles and motorcycles, frisbees, rifled bullets, and gyroscopes owe their useful properties to conservation of angular momentum. Conservation of angular momentum is also why hurricanes form spirals and neutron stars have high rotational rates. In general, conservation limits the possible motion of a system, but it does not uniquely determine it. The three-dimensional angular momentum for a point particle is classically represented as a pseudovector , the cross product of the particle's position vector (relative to some origin) and its momentum vector; the latter is in Newtonian mechanics. Unlike linear momentum, angular mome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charge (physics)
In physics, a charge is any of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges correspond to the time-invariant generators of a symmetry group, and specifically, to the generators that commute with the Hamiltonian. Charges are often denoted by the letter ''Q'', and so the invariance of the charge corresponds to the vanishing commutator ,H0, where H is the Hamiltonian. Thus, charges are associated with conserved quantum numbers; these are the eigenvalues ''q'' of the generator ''Q''. Abstract definition Abstractly, a charge is any generator of a continuous symmetry of the physical system under study. When a physical system has a symmetry of some sort, Noether's theorem implies the existence of a conserved current. The thing that "flows" in the current is the "charge", the charge is the generator of the (local) symmetry group. This charge is sometimes called the Noether charge. Thus, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementary particles, theoretically with the same amount of matter, have nonetheless different masses. Mass in modern physics has multiple definitions which are conceptually distinct, but physically equivalent. Mass can be experimentally defined as a measure of the body's inertia, meaning the resistance to acceleration (change of velocity) when a net force is applied. The object's mass also determines the strength of its gravitational attraction to other bodies. The SI base unit of mass is the kilogram (kg). In physics, mass is not the same as weight, even though mass is often determined by measuring the object's weight using a spring scale, rather than balance scale comparing it directly with known masses. An object on the Moon would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
