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Magnetosphere Chronology
The following is a chronology of discoveries concerning the magnetosphere. *1600 - William Gilbert in London suggests the Earth is a giant magnet. *1741 - Hiorter and Anders Celsius note that the polar aurora is accompanied by a disturbance of the magnetic needle. *1820 - Hans Christian Ørsted discovers electric currents create magnetic effects. André-Marie Ampère deduces that magnetism is basically the force between electric currents. *1833 - Carl Friedrich Gauss and Wilhelm Weber worked out the mathematical theory for separating the inner and outer Magnetosphere sources of Earth's magnetic field. *1843 - Samuel Schwabe, a German amateur astronomer, shows the existence of an 11-year sunspot cycle. *1859 - Richard Carrington in England observes a solar flare; 17 hours later a large magnetic storm begins. *1892 - George Ellery Hale introduces the spectroheliograph, observing the Sun in hydrogen light from the chromosphere, a sensitive way of detecting flares. He confirms the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetosphere
In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior dynamo. In the space environment close to a planetary body, the magnetic field resembles a magnetic dipole. Farther out, field lines can be significantly distorted by the flow of electrically conducting plasma, as emitted from the Sun (i.e., the solar wind) or a nearby star. Planets having active magnetospheres, like the Earth, are capable of mitigating or blocking the effects of solar radiation or cosmic radiation, that also protects all living organisms from potentially detrimental and dangerous consequences. This is studied under the specialized scientific subjects of plasma physics, space physics and aeronomy. History Study of Earth's magnetosphere began in 1600, when William Gilbert discovered that the magnetic field on the surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guglielmo Marconi
Guglielmo Giovanni Maria Marconi, 1st Marquis of Marconi (; 25 April 187420 July 1937) was an Italians, Italian inventor and electrical engineering, electrical engineer, known for his creation of a practical radio wave-based Wireless telegraphy, wireless telegraph system. This led to Marconi being credited as the inventor of radio, and he shared the 1909 Nobel Prize in Physics with Karl Ferdinand Braun "in recognition of their contributions to the development of wireless telegraphy".Guglielmo Marconi: The Nobel Prize in Physics 1909 . nobelprize.org Marconi was also an entrepreneur, businessman, and founder of Marconi Company, The Wireless Telegraph & Signal Company in the United Kingdom of Great Britain and Ireland, United Kingdom in 1897 (which became the Marconi Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eugene Parker
Eugene Newman Parker (June 10, 1927 – March 15, 2022) was an American solar and plasma physicist. In the 1950s he proposed the existence of the solar wind and that the magnetic field in the outer Solar System would be in the shape of a Parker spiral, predictions that were later confirmed by spacecraft measurements. In 1987, Parker proposed the existence of nanoflares, a leading candidate to explain the coronal heating problem. Parker obtained his PhD from Caltech and spent four years as a postdoctoral researcher at the University of Utah. He joined University of Chicago in 1955 and spent the rest of his career there, holding positions in the physics department, the astronomy and astrophysics department, and the Enrico Fermi Institute. Parker was elected to the National Academy of Sciences in 1967. In 2017, NASA named its Parker Solar Probe in his honor, the first NASA spacecraft named after a living person. Biography Parker was born in Houghton, Michigan to Glenn and Hele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explorer 3
Explorer 3 (Harvard designation 1958 Gamma) was an American artificial satellite launched into medium Earth orbit in 1958. It was the second successful launch in the Explorer program, and was nearly identical to the first U.S. satellite Explorer 1 in its design and mission. Background The U.S. Earth satellite program began in 1954 as a joint U.S. Army and U.S. Navy proposal, called Project Orbiter, to put a scientific satellite into orbit during the International Geophysical Year (IGY). The proposal, using a U.S. Army Redstone missile, was rejected in 1955 by the Eisenhower administration in favor of the U.S. Navy's Project Vanguard, using a booster advertised as more civilian in nature. Following the launch of the Soviet satellite Sputnik 1 on 4 October 1957, the initial Project Orbiter program was revived as the Explorer program to catch up with the Soviet Union. Launch The satellite was launched from Cape Canaveral Missile Test Center of the Atlantic Missile Range (AMR), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explorer 1
Explorer 1 was the first satellite launched by the United States in 1958 and was part of the U.S. participation in the International Geophysical Year (IGY). The mission followed the first two satellites the previous year; the Soviet Union's Sputnik 1 and Sputnik 2, beginning the Cold War Space Race between the two nations. Explorer 1 was launched on 1 February 1958 at 03:47:56 GMT (or 31 January 1958 at 22:47:56 Eastern Time) atop the first Juno booster from LC-26A at the Cape Canaveral Missile Test Center of the Atlantic Missile Range (AMR), in Florida. It was the first spacecraft to detect the Van Allen radiation belt, returning data until its batteries were exhausted after nearly four months. It remained in orbit until 1970. Explorer 1 was given Satellite Catalog Number 00004 and the Harvard designation 1958 Alpha 1, the forerunner to the modern International Designator. Background The U.S. Earth satellite program began in 1954 as a joint U.S. Army and U.S. Navy pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sputnik 1
Sputnik 1 (; see § Etymology) was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program. It sent a radio signal back to Earth for three weeks before its three silver-zinc batteries ran out, and continued in orbit for three months until aerodynamic drag caused it to fall back into the atmosphere on 4 January 1958. It was a polished metal sphere in diameter with four external radio antennas to broadcast radio pulses. Its radio signal was easily detectable by amateur radio operators, and the 65° orbital inclination made its flight path cover virtually the entire inhabited Earth. The satellite's unanticipated success precipitated the American Sputnik crisis and triggered the Space Race, part of the Cold War. The launch was the beginning of a new era of political, military, technological and scientific developments. The word ''sputnik'' is Russian for ''satellite'' w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Van Allen
James Alfred Van Allen (September 7, 1914August 9, 2006) was an American space scientist at the University of Iowa. He was instrumental in establishing the field of magnetospheric research in space. The Van Allen radiation belts were named after him, following his discovery using Geiger–Müller tube instruments on the 1958 satellites (Explorer 1, Explorer 3, and Pioneer 3) during the International Geophysical Year. Van Allen led the scientific community in putting scientific research instruments on space satellites. Early years and education Van Allen was born on 7 September 1914 on a small farm near Mount Pleasant, Iowa. As a child, he was fascinated by mechanical and electrical devices and was an avid reader of ''Popular Mechanics'' and ''Popular Science'' magazines. He once horrified his mother by constructing a Tesla coil that produced foot-long sparks and caused his hair to stand on end. A fellowship allowed him to continue studying nuclear physics at the Carnegie Ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melvin B
Melvin is a masculine given name and surname, likely a variant of Melville and a descendant of the French surname de Maleuin and the later Melwin. It may alternatively be spelled as Melvyn or, in Welsh, Melfyn and the name Melivinia or Melva may be used a feminine form. Of Norman French origin, originally Malleville, which translates to "bad town," it likely made its way into usage in Scotland as a result of the Norman conquest of England. It came into use as a given name as early as the 19th century, in English-speaking populations. As a name Given name Academics *Melvin Calvin (1911–1997), American chemist who discovered the Calvin cycle *Melvin Day (1923–2016), New Zealand artist and art historian *Melvin Hochster (born 1943), American mathematician *Melvin Konner (born 1946), Professor of Anthropology *Melvin Schwartz (1932–2006), American physicist who won the Nobel Prize in Physics in 1988 * Melvin Alvah Traylor, Jr. (1915–2008), American ornithologist Busines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leslie H
Leslie may refer to: * Leslie (name), a name and list of people with the given name or surname, including fictional characters Families * Clan Leslie, a Scottish clan with the motto "grip fast" * Leslie (Russian nobility), a Russian noble family of Scottish origin Places Canada * Leslie, Saskatchewan * Leslie Street, a road in Toronto and York Region, Ontario ** Leslie (TTC), a subway station ** Leslie Street Spit, an artificial spit in Toronto United States *Leslie, Arkansas *Leslie, Georgia *Leslie, Michigan *Leslie, Missouri *Leslie, West Virginia *Leslie, Wisconsin *Leslie Township, Michigan *Leslie Township, Minnesota Elsewhere * Leslie Dam, a dam in Warwick, Queensland, Australia * Leslie, Mpumalanga, South Africa * Leslie, Aberdeenshire, Scotland, see List of listed buildings in Leslie, Aberdeenshire * Leslie, Fife, Scotland, UK Other uses * Leslie speaker system * Leslie Motor Car company * Leslie Controls, Inc. * Leslie (singer) (born 1985), French singer See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whistler (radio)
A whistler is a very low frequency (VLF) electromagnetic (radio) wave generated by lightning. Originally published by Stanford University Press, Stanford, California (1965). Frequencies of terrestrial whistlers are 1 kHz to 30 kHz, with a maximum amplitude usually at 3 kHz to 5 kHz. Although they are electromagnetic waves, they occur at audio frequencies, and can be converted to audio using a suitable receiver. They are produced by lightning strikes (mostly intracloud and return-path) where the impulse travels along the Earth's magnetic field lines from one hemisphere to the other. They undergo dispersion of several kHz due to the slower velocity of the lower frequencies through the plasma environments of the ionosphere and magnetosphere. Thus they are perceived as a descending tone which can last for a few seconds. The study of whistlers categorizes them into Pure Note, Diffuse, 2-Hop, and Echo Train types. Voyager 1 and Voyager 2, 2 spacecraft detected w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () 1, where \nu_ is the electron gyrofrequency and \nu_ is the electron collision rate. It is often the case that the electrons are magnetized while the ions are not. Magnetized plasmas are ''anisotropic'', meaning that their properties in the direction parallel to the magnetic field are different from those perpendicular to it. While electric fields in plasmas are usually small due to the plasma high conductivity, the electric field associated with a plasma moving with velocity \mathbf in the magnetic field \mathbf is given by the usual Lorentz force, Lorentz formula \mathbf = -\mathbf\times\mathbf, and is not affected by Debye shielding. Mathematical descriptions To completely describe the state of a plasma, all of the particle locations and velocities that describe the electromagnetic field in the plasma region would need to be written down. However, it is generally not practical or necessary to keep track of all the particles in a plasma. Therefore, plasma physicist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sydney Chapman (astronomer)
Sydney Chapman (29 January 1888 – 16 June 1970) was a British mathematician and geophysicist. His work on the kinetic theory of gases, solar-terrestrial physics, and the Earth's ozone layer has inspired a broad range of research over many decades. Education and early life Chapman was born in Eccles, near Salford in England and began his advanced studies at a technical institute, now the University of Salford, in 1902. In 1904 at age 16, Chapman entered the University of Manchester. He competed for a scholarship to the university offered by his home county, and was the last student selected. Chapman later reflected, "I sometimes wonder what would have happened if I'd hit one place lower." He initially studied engineering in the department headed by Osborne Reynolds. Chapman was taught mathematics by Horace Lamb, the Beyer professor of mathematics, and J. E. Littlewood, who came from Cambridge in Chapman's final year at Manchester. Although he graduated with an engineerin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
