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Richard Matzner
Richard Alfred Matzner is an American physicist, working mostly in the field of general relativity and cosmology, including numerical relativity, kinetic theory, black hole physics, and gravitational radiation. He is Professor of Physics at the University of Texas at Austin where he directed the Center for Relativity. In 1993 he organized and was Lead Principal Investigator of an NSF/ ARPA funded computational Grand Challenge program involving ten university teams seeking computational descriptions for the interaction of black holes as potential sources for observable gravitational radiation. His work leading what became known as the Binary Black Hole Grand Challenge Alliance featured in Kip Thorne's Nobel Prize lecture, including when Matzner and Alliance collaborators wagered Thorne that numerical relativity would produce a simulated waveform comparable to observation prior to the first LIGO detection. Matzner and colleagues eventually won, Thorne saying he "conceded the bet wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity
General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General theory of relativity, 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 in physics, time, or four-dimensional spacetime. In particular, the ''curvature of spacetime'' is directly related to the energy and momentum of whatever is present, including matter and radiation. 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 gravity in classical mechanics, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Numerical Relativity
Numerical relativity is one of the branches of general relativity that uses numerical methods and algorithms to solve and analyze problems. To this end, supercomputers are often employed to study black holes, gravitational waves, neutron stars and many other phenomena described by Albert Einstein's theory of general relativity. A currently active field of research in numerical relativity is the simulation of relativistic binaries and their associated gravitational waves. Overview A primary goal of numerical relativity is to study spacetimes whose exact form is not known. The spacetimes so found computationally can either be fully dynamical, stationary or static and may contain matter fields or vacuum. In the case of stationary and static solutions, numerical methods may also be used to study the stability of the equilibrium spacetimes. In the case of dynamical spacetimes, the problem may be divided into the initial value problem and the evolution, each requiring different me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frame-dragging
Frame-dragging is an effect on spacetime, predicted by Albert Einstein's General relativity, general theory of relativity, that is due to non-static stationary distributions of mass–energy. A stationary Field (physics), field is one that is in a steady state, but the masses causing that field may be non-static — rotating, for instance. More generally, the subject that deals with the effects caused by mass–energy currents is known as gravitoelectromagnetism, which is analogous to the magnetism of classical electromagnetism. The first frame-dragging effect was derived in 1918, in the framework of general relativity, by the Austrian physicists Josef Lense and Hans Thirring, and is also known as the Lense–Thirring effect. They predicted that the rotation of a massive object would distort the Metric tensor (general relativity), spacetime metric, making the orbit of a nearby test particle precess. This does not happen in Newtonian mechanics for which the gravitational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LAGEOS
LAGEOS (), Laser Geodynamics Satellite or Laser Geometric Environmental Observation Survey, are a series of two scientific research satellites designed to provide an orbiting laser ranging benchmark for geodynamical studies of the Earth. Each satellite is a high-density passive laser reflector in a very stable medium Earth orbit (MEO). Function and operation The spacecraft are aluminum-covered brass spheres with diameters of and masses of , covered with 426 cube-corner retroreflectors, giving them the appearance of disco balls. Of these retroreflectors, 422 are made from fused silica glass while the remaining 4 are made from germanium to obtain measurements in the infrared for experimental studies of reflectivity and satellite orientation. They have no on-board sensors or electronics, and are not attitude-controlled. They orbit at an altitude of , well above low Earth orbit and well below geostationary orbit, at orbital inclinations of 109.8 and 52.6 degrees. Measuremen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity
General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General theory of relativity, 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 in physics, time, or four-dimensional spacetime. In particular, the ''curvature of spacetime'' is directly related to the energy and momentum of whatever is present, including matter and radiation. 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 gravity in classical mechanics, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cambridge
The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, world's third-oldest university in continuous operation. The university's founding followed the arrival of scholars who left the University of Oxford for Cambridge after a dispute with local townspeople. The two ancient university, ancient English universities, although sometimes described as rivals, share many common features and are often jointly referred to as Oxbridge. In 1231, 22 years after its founding, the university was recognised with a royal charter, granted by Henry III of England, King Henry III. The University of Cambridge includes colleges of the University of Cambridge, 31 semi-autonomous constituent colleges and List of institutions of the University of Cambridge#Schools, Faculties, and Departments, over 150 academic departm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Misner
Charles William Misner (; June 13, 1932 – July 24, 2023) was an American physicist and one of the authors of ''Gravitation''. His specialties included general relativity and cosmology. His work has also provided early foundations for studies of quantum gravity and numerical relativity. Biography Academic training and university positions Misner received his Bachelor of Science, B.S. degree from the University of Notre Dame in 1952. He then moved to Princeton University, where he earned an Master of Arts, M.A. in 1954 and completed his Ph.D. in 1957. His dissertation, ''Outline of Feynman Quantization of General Relativity; Derivation of Field Equations; Vanishing of the Hamiltonian'', was completed under John Archibald Wheeler, John Wheeler. Prior to completing his Ph.D., Misner joined the faculty of the Princeton Physics Department with the rank of Instructor (1956–1959), and was subsequently promoted to assistant professor (1959–1963). In 1963 he moved to the Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIGO
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Prior to LIGO, all data about the universe has come in the form of light and other forms of electromagnetic radiation, from limited direct exploration on relatively nearby Solar System objects such as the Moon, Mars, Venus, Jupiter and their moons, asteroids etc, and from high energy cosmic particles. Initially, two large observatories were built in the United States with the aim of detecting gravitational waves by laser interferometry. Two additional, smaller gravity wave observatories are now operational in Japan KAGRA, (KAGRA) and Italy Virgo interferometer, (Virgo). The two LIGO observatories use mirrors spaced four kilometers apart to measure changes in length—over an effective span of 1120 km—of less than one ten-thousandth the charge radius, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobel Prize
The Nobel Prizes ( ; ; ) are awards administered by the Nobel Foundation and granted in accordance with the principle of "for the greatest benefit to humankind". The prizes were first awarded in 1901, marking the fifth anniversary of Alfred Nobel, Alfred Nobel's death. The original Nobel Prizes covered five fields: Nobel Prize in Physics, physics, Nobel Prize in Chemistry, chemistry, Nobel Prize in Physiology or Medicine, physiology or medicine, Nobel Prize in Literature, literature, and Nobel Peace Prize, peace, specified in Nobel's will. A sixth prize, the Nobel Memorial Prize in Economic Sciences, Prize in Economic Sciences, was established in 1968 by Sveriges Riksbank (Sweden's central bank) in memory of Alfred Nobel. The Nobel Prizes are widely regarded as the most prestigious awards available in their respective fields.Nobel Prize#Shalev69, Shalev, p. 8. Except in extraordinary circumstances, such as war, all six prizes are given annually. Each recipient, known as a laur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kip Thorne
Kip Stephen Thorne (born June 1, 1940) is an American theoretical physicist and writer known for his contributions in gravitational physics and astrophysics. Along with Rainer Weiss and Barry C. Barish, he was awarded the 2017 Nobel Prize in Physics for his contributions to the LIGO detector and the observation of gravitational waves. A longtime friend and colleague of Stephen Hawking and Carl Sagan, he was the Richard P. Feynman Professor of Theoretical Physics at the California Institute of Technology (Caltech) until 2009 and speaks of the astrophysical implications of the general theory of relativity. He continues to do scientific research and scientific consulting, a notable example of which was for the Christopher Nolan film '' Interstellar''. Life and career Thorne was born on June 1, 1940, in Logan, Utah. His father, D. Wynne Thorne (1908–1979), was a professor of soil chemistry at Utah State University, and his mother, Alison (née Comish; 1914–2004), was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grand Challenge
Grand Challenges are difficult but important problems set by various institutions or professions to encourage solutions or advocate for the application of government or philanthropic funds especially in the most highly developed economies Gould, M. "GIScience grand challenges: How can research and technology in this field address big-picture problems? ArcUser, 13 (4), 64–65." (2010). Accessed a/ref> and Grand challenges are more than ordinary research questions or priorities, they are end results or outcomes that are global in scale; very difficult to accomplish, yet offer hope of being ultimately tractable; demand an extensive number of research projects across many technical and non-technical disciplines and accompanied by well-defined metrics. Lastly, Grand challenges "require coordinated, collaborative, and collective efforts" and must capture "the popular imagination, and thus political support." In engineering * Grand Challenges: A Strategic Plan for Bridge Engineerin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Research Projects Agency
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military. Originally known as the Advanced Research Projects Agency (ARPA), the agency was created on February 7, 1958, by President Dwight D. Eisenhower in response to the Soviet launching of Sputnik 1 in 1957. By collaborating with academia, industry, and government partners, DARPA formulates and executes research and development projects to expand the frontiers of technology and science, often beyond immediate U.S. military requirements.Dwight D. Eisenhower and Science & Technology, (2008). Dwight D. Eisenhower Memorial CommissionSource The name of the organization first changed from its founding name, ARPA, to DARPA, in March 1972, changing back to ARPA in February 1993, then reverted to DARPA in March 1996. ''The Economist'' has called DARPA "the agency that shaped the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
