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Gravitational-wave Observatory
A gravitational-wave detector (used in a gravitational-wave observatory) is any device designed to measure tiny distortions of spacetime called gravitational waves. Since the 1960s, various kinds of gravitational-wave detectors have been built and constantly improved. The present-day generation of laser interferometers has reached the necessary sensitivity to detect gravitational waves from astronomical sources, thus forming the primary tool of gravitational-wave astronomy. The first direct observation of gravitational waves was made in September 2015 by the Advanced LIGO observatories, detecting gravitational waves with wavelengths of a few thousand kilometers from a merging binary of stellar black holes. In June 2023, four pulsar timing array collaborations presented the first strong evidence for a gravitational wave background of wavelengths spanning light years, most likely from many binaries of supermassive black holes. Challenge The direct detection of gravitational wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MiniGrail
MiniGRAIL was a third-generation resonant mass antenna, a massive sphere designed to detect gravitational waves. The MiniGRAIL was the first such detector to use a spherical design. It is located at Leiden University in the Netherlands. The project was managed by the Kamerlingh Onnes Laboratory. A team from the Department of Theoretical Physics of the University of Geneva, Switzerland, was also heavily involved. The project was terminated in 2005. Gravitational waves are a type of radiation that is emitted by objects that have mass and are undergoing acceleration. The strongest sources of gravitational waves are suspected to be compact objects such as neutron stars and black holes. This detector may be able to detect certain types of instabilities in rotating single and binary neutron stars, and the merger of small black holes or neutron stars. Design A spherical design has the benefit of being able to detect gravitational waves arriving from any direction, and it is sensitive t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIGO Schematic (multilang)
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) and Italy (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 diameter of a proton. (that is, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allegro Gravitational-wave Detector
Allegro was a ground-based, cryogenic resonant Weber bar, gravitational-wave detector run by Warren Johnson, et al. at Louisiana State University in Baton Rouge, Louisiana. The detector was commissioned in the early 1990s, and was decommissioned in 2008. Mechanical design The resonant bar in Allegro is 2300 kg of aluminum, 3 meters in length. Suspended in a cryogenic vacuum tank at 4.2 Kelvin, the bar's natural resonant frequency (the lowest longitudinal mode) is near 904 Hz. The strain on the bar is measured by coupling a second, much lighter, suspended mass to the main heavier mass as a mechanical transformer at the same resonant frequency. Therefore, small motions of the primary mass generate much larger motions in the smaller mass. The differential displacement of the two masses is recorded using an inductive transducer and amplifier (a SQUID). Collaboration with LIGO Due its close proximity to the LIGO The Laser Interferometer Gravitational-Wave Observatory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainer Weiss
Rainer "Rai" Weiss ( , ; born September 29, 1932) is a German-American physicist, known for his contributions in gravitation, gravitational physics and astrophysics. He is a professor of physics emeritus at Massachusetts Institute of Technology, MIT and an adjunct professor at Louisiana State University, LSU. He is best known for inventing the laser interferometric technique which is the basic operation of LIGO. He was Chair of the Cosmic Background Explorer, COBE Science Working Group. In 2017, Weiss was awarded the Nobel Prize in Physics, along with Kip Thorne and Barry Barish, "for decisive contributions to the LIGO detector and the observation of gravitational waves". Weiss has helped realize a number of challenging experimental tests of fundamental physics. He is a member of the Fermilab Holometer experiment, which uses a 40m Michelson Interferometer, laser interferometer to measure properties of space and time at quantum scale and provide Planck-precision tests of quantum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometry
Interferometry is a technique which uses the ''interference (wave propagation), interference'' of Superposition principle, superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, Optical fiber, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, Nuclear physics, nuclear and particle physics, plasma physics, interactome, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into two beams that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multipole Moments
A multipole expansion is a mathematical series representing a function that depends on angles—usually the two angles used in the spherical coordinate system (the polar and azimuthal angles) for three-dimensional Euclidean space, \R^3. Multipole expansions are useful because, similar to Taylor series, oftentimes only the first few terms are needed to provide a good approximation of the original function. The function being expanded may be real- or complex-valued and is defined either on \R^3, or less often on \R^n for some other Multipole expansions are used frequently in the study of electromagnetic and gravitational fields, where the fields at distant points are given in terms of sources in a small region. The multipole expansion with angles is often combined with an expansion in radius. Such a combination gives an expansion describing a function throughout three-dimensional space. The multipole expansion is expressed as a sum of terms with progressively finer angular featu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leiden University
Leiden University (abbreviated as ''LEI''; ) is a Public university, public research university in Leiden, Netherlands. Established in 1575 by William the Silent, William, Prince of Orange as a Protestantism, Protestant institution, it holds the distinction of being the oldest university in the Netherlands of today. During the Dutch Golden Age scholars from around Europe were attracted to the Dutch Republic for its climate of intellectual tolerance. Individuals such as René Descartes, Rembrandt, Christiaan Huygens, Hugo Grotius, Benedictus Spinoza, and later Baron d'Holbach were active in Leiden and environs. The university has seven academic faculties and over fifty subject departments, housing more than forty national and international research institutes. Its historical primary campus consists of several buildings spread over Leiden, while a second campus located in The Hague houses a liberal arts college (Leiden University College The Hague) and several of its faculties. It i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mario Schenberg (Gravitational Wave Detector)
The Mario Schenberg (Gravitational Wave Detector, or Brazilian Graviton Project or Graviton) is a spherical, resonant-mass, gravitational wave detector formerly run by the Physics Institute of the University of São Paulo, named after Mário Schenberg. Similar to the Dutch-run MiniGrail, the 1.15 ton, 65 cm diameter spherical test mass is suspended in a cryogenic vacuum enclosure, kept at 20 mK; and the sensors (transducers) for this detector/antenna are developed at the National Institute for Space Research (INPE), in Sao José dos Campos, Brazil. As of 2016, the antenna has not detected any gravitational waves, and development of the antenna continues. It has been decided that the antenna will be transferred from the University of São Paulo to INPE. See also * List of radio telescopes This is a list of radio telescopes – over one hundred – that are or have been used for radio astronomy. The list includes both single dishes and interferometric arrays. The list i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
INFN
The Istituto Nazionale di Fisica Nucleare (INFN; "National Institute for Nuclear Physics") is the coordinating institution for nuclear, particle, theoretical and astroparticle physics in Italy. History INFN was founded on the 8th of August 1951, to further the nuclear physics research tradition initiated by Enrico Fermi in Rome, in the 1930s. The INFN collaborates with CERN, Fermilab and various other laboratories in the world. In recent years it has provided important contributions to grid computing. During the latter half of the 1950s, the INFN designed and constructed the first Italian electron accelerator—the electron synchrotron developed in Frascati. In the early 1960s, it also constructed in Frascati the first ever electron-positron collider ( ADA - ''Anello Di Accumulazione''), under the scientific leadership of Bruno Touschek. In 1968, Frascati began operating ADONE (''big'' AdA), which was the first high-energy particle collider, having a beam energy of 1.5 GeV. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SQUID
A squid (: squid) is a mollusc with an elongated soft body, large eyes, eight cephalopod limb, arms, and two tentacles in the orders Myopsida, Oegopsida, and Bathyteuthida (though many other molluscs within the broader Neocoleoidea are also called ''squid'' despite not strictly fitting these criteria). Like all other cephalopods, squid have a distinct head, Symmetry (biology)#Bilateral symmetry, bilateral symmetry, and a mantle (mollusc), mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius (cephalopod), gladius or pen, made of chitin. Squid diverged from other cephalopods during the Jurassic and occupy a similar Ecological niche, role to teleost fish as open-water predators of similar size and behaviour. They play an important role in the open-water food web. The two long tentacles are used to grab prey and the eight arms to hold and control it. The beak then cuts the food into suitable size chunks for swal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SN1987A
SN 1987A was a Type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately from Earth and was the closest observed supernova since Kepler's Supernova in 1604. Light and neutrinos from the explosion reached Earth on February 23, 1987, and it was designated "SN 1987A" as the first supernova discovered that year. Its brightness peaked in May of that year, with an apparent magnitude of about 3, brighter than the constellation's brightest star, Alpha Doradus. It was the first supernova that modern astronomers were able to study in great detail, and its observations have provided much insight into core-collapse supernovae. SN 1987A provided the first opportunity to confirm by direct observation the radioactive source of the energy for visible light emissions, by detecting predicted gamma-ray line radiation from two of its abundant radioactive nuclei. This proved the radioactive nature of the long-duration post ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
