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Bernard F. Burke
Bernard Flood Burke (June 7, 1928 – August 5, 2018) was an American astronomer. He co-discovered radio emission from Jupiter, and was part of the team that discovered the first Einstein ring in 1988. Early life Burke was born on June 7, 1928 in Brighton, Boston. He had two sisters, Sarah (Sally) Berenson and Clare Malloy. He went to Lexington High School. Burke studied for an undergraduate physics degree at Massachusetts Institute of Technology (MIT), graduating in 1950, before going on to study for a PhD in physics, graduating again from MIT in 1953. Career From 1953 until 1965, he was employed to carry out radio astronomy research by Carnegie Institution of Washington, where he also headed the Radio Astronomy Section from 1962 until 1965. Burke became a faculty member of the Physics department at MIT and later was the William A. M. Burden Professor of Astrophysics, Emeritus. He was a principal investigator of the Kavli Institute for Astrophysics and Space Researc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Emission
Radio waves are a type of electromagnetic radiation with the longest wavelengths in the electromagnetic spectrum, typically with frequencies of 300 gigahertz (GHz) and below. At 300 GHz, the corresponding wavelength is 1 mm (shorter than a grain of rice); at 30 Hz the corresponding wavelength is (longer than the radius of the Earth). Like all electromagnetic waves, radio waves in a vacuum travel at the speed of light, and in the Earth's atmosphere at a close, but slightly lower speed. Radio waves are generated by charged particles undergoing acceleration, such as time-varying electric currents. Naturally occurring radio waves are emitted by lightning and astronomical objects, and are part of the blackbody radiation emitted by all warm objects. Radio waves are generated artificially by an electronic device called a transmitter, which is connected to an antenna which radiates the waves. They are received by another antenna connected to a radio receiver, whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chess
Chess is a board game for two players, called White and Black, each controlling an army of chess pieces in their color, with the objective to checkmate the opponent's king. It is sometimes called international chess or Western chess to distinguish it from related games, such as xiangqi (Chinese chess) and shogi (Japanese chess). The recorded history of chess goes back at least to the emergence of a similar game, chaturanga, in seventh-century India. The rules of chess as we know them today emerged in Europe at the end of the 15th century, with standardization and universal acceptance by the end of the 19th century. Today, chess is one of the world's most popular games, played by millions of people worldwide. Chess is an abstract strategy game that involves no hidden information and no use of dice or cards. It is played on a chessboard with 64 squares arranged in an eight-by-eight grid. At the start, each player controls sixteen pieces: one king, one queen, two rooks, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marblehead, Massachusetts
Marblehead is a coastal New England town in Essex County, Massachusetts, along the North Shore (Massachusetts), North Shore. Its population was 20,441 at the 2020 United States Census, 2020 census. The town lies on a small peninsula that extends into the northern part of Massachusetts Bay. Attached to the town is a near island, known as Marblehead Neck, connected to the mainland by a narrow isthmus. Marblehead Harbor, protected by shallow shoals and rocks from the open sea, lies between the mainland and the Neck. Beside the Marblehead town center, two other villages lie within the town: the Old Town, which was the original town center, and Clifton, which lies along the border with the neighboring town of Swampscott, Massachusetts, Swampscott. A town with roots in commercial fishing and yachting, Marblehead was a major shipyard and is often referred to as the birthplace of the United States Navy, American Navy, a title sometimes disputed with nearby Beverly, Massachusetts, Beve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in the southwestern United States. Depending on differing definitions between Canada and the U.S., its northern terminus is located either in northern British Columbia's Terminal Range south of the Liard River and east of the Trench, or in the northeastern foothills of the Brooks Range/ British Mountains that face the Beaufort Sea coasts between the Canning River and the Firth River across the Alaska-Yukon border. Its southernmost point is near the Albuquerque area adjacent to the Rio Grande rift and north of the Sandia–Manzano Mountain Range. Being the easternmost portion of the North American Cordillera, the Rockies are distinct from the tectonically younger Cascade Range and Sierra Nevada, which both lie farther to its west. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Mountains (New Hampshire)
The White Mountains are a mountain range covering about a quarter of the state of New Hampshire and a small portion of western Maine in the United States. They are part of the northern Appalachian Mountains and the most rugged mountains in New England. The range is heavily visited due to its proximity to Boston, New York City, and Montreal. Most of the area is public land, including the White Mountain National Forest and a number of state parks. Its most famous mountain is Mount Washington, which is the highest peak in the Northeastern U.S. and for 76 years held the record for fastest surface wind gust in the world ( in 1934). Mount Washington is part of a line of summits, the Presidential Range, that are named after U.S. presidents and other prominent Americans. The White Mountains also include the Franconia Range, Sandwich Range, Carter-Moriah Range and Kinsman Range in New Hampshire, and the Mahoosuc Range straddling the border between it and Maine. In all, there are 48 peak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Radio Astronomy Observatory
The National Radio Astronomy Observatory (NRAO) is a federally funded research and development center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc. for the purpose of radio astronomy. NRAO designs, builds, and operates its own high-sensitivity radio telescopes for use by scientists around the world. Locations Charlottesville, Virginia The NRAO headquarters is located on the campus of the University of Virginia in Charlottesville, Virginia. The North American ALMA Science Center and the NRAO Technology Center and Central Development Laboratory are also in Charlottesville. Green Bank, West Virginia NRAO was, until October 2016, the operator of the world's largest fully steerable radio telescope, the Robert C. Byrd Green Bank Telescope, which stands near Green Bank, West Virginia. The observatory contains several other telescopes, among them the telescope that utilizes an equatorial mount uncommon for radio te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Francis Graham-Smith
Sir Francis Graham-Smith (born 25 April 1923) is a British astronomer. He was the thirteenth Astronomer Royal from 1982 to 1990 and was knighted in 1986. Biography Education He was educated at Rossall School, Lancashire, England, and attended Downing College, Cambridge from 1941. Career In the late 1940s he worked at the University of Cambridge on the Long Michelson Interferometer. In 1964 he was appointed Professor of Radio Astronomy the University of Manchester and in 1981 director of the Nuffield Radio Astronomy Laboratories, part of the University of Manchester at Jodrell Bank. He was also Director of the Royal Greenwich Observatory from 1975 to 1981. He appeared in Episode 13 of Series 4 of Treasure Hunt when the show visited Jodrell Bank, giving presenter Anneka Rice a piggy back to allow her to reach a clue. Bibliography * ''Optics'' (1971) * ''Pathways to the Universe'' (1988) * ''Pulsar Astronomy'' (1990) * ''An Introduction to Radio Astronomy'' (1997) * ''Unsee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VLBI
Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. In VLBI a signal from an astronomical radio source, such as a quasar, is collected at multiple radio telescopes on Earth or in space. The distance between the radio telescopes is then calculated using the time difference between the arrivals of the radio signal at different telescopes. This allows observations of an object that are made simultaneously by many radio telescopes to be combined, emulating a telescope with a size equal to the maximum separation between the telescopes. Data received at each antenna in the array include arrival times from a local atomic clock, such as a hydrogen maser. At a later time, the data are correlated with data from other antennas that recorded the same radio signal, to produce the resulting image. The resolution achievable using interferometry is proportional to the observing frequency. The VLBI technique enables the distance between t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Einstein Ring
An Einstein ring, also known as an Einstein–Chwolson ring or Chwolson ring (named for Orest Chwolson), is created when light from a galaxy or star passes by a massive object en route to the Earth. Due to gravitational lensing, the light is diverted, making it seem to come from different places. If source, lens, and observer are all in perfect alignment, the light appears as a ring. Introduction Gravitational lensing is predicted by Albert Einstein's theory of general relativity. Instead of light from a source traveling in a straight line (in three dimensions), it is bent by the presence of a massive body, which distorts spacetime. An Einstein Ring is a special case of gravitational lensing, caused by the exact alignment of the source, lens, and observer. This results in symmetry around the lens, causing a ring-like structure. The size of an Einstein ring is given by the Einstein radius. In radians, it is :\theta_1 = \sqrt, where : G is the gravitational constant, : M is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Lenses
A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known as gravitational lensing, and the amount of bending is one of the predictions of Albert Einstein's general theory of relativity. Treating light as corpuscles travelling at the speed of light, Newtonian physics also predicts the bending of light, but only half of that predicted by general relativity. Although Einstein made unpublished calculations on the subject in 1912, Orest Khvolson (1924) and Frantisek Link (1936) are generally credited with being the first to discuss the effect in print. However, this effect is more commonly associated with Einstein, who published an article on the subject in 1936. Fritz Zwicky posited in 1937 that the effect could allow galaxy clusters to act as gravitational lenses. It was not until 1979 that this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crab Nebula
The Crab Nebula (catalogue designations Messier object, M1, New General Catalogue, NGC 1952, Taurus (constellation), Taurus A) is a supernova remnant and pulsar wind nebula in the constellation of Taurus (constellation), Taurus. The common name comes from William Parsons, 3rd Earl of Rosse, who observed the object in 1842 using a telescope and produced a drawing that looked somewhat like a crab. The nebula was discovered by English astronomer John Bevis in 1731, and it corresponds with SN 1054, a bright supernova recorded by Chinese astronomy, Chinese astronomers in 1054. The nebula was the first astronomical object identified that corresponds with a historical supernova explosion. At an apparent magnitude of 8.4, comparable to that of Titan (moon), Saturn's moon Titan, it is not visible to the naked eye but can be made out using binoculars under favourable conditions. The nebula lies in the Perseus Arm of the Milky Way galaxy, at a distance of about from Earth. It has a diame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
