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Karl Rudolph Powalky
Karl Rudolph Powalky (19 June 1817 – 11 July 1881) was a German astronomer known for his computational work on estimating cometary paths and minor planets and for his estimation of the solar parallax at . Nothing is known of Powalky's younger days except that he was born in Neudietendorf, Thuringia. He worked at the Hamburg observatory from 1842 to 1847 and worked as a computer for Peter Andreas Hansen from 1850 to 1856. His achievement was in the calculation of the solar parallax of between and 8.86 arcseconds based on observations made during a transit of Venus in 1769 resulting in an estimate of the astronomical unit (AU) which is the mean distance of the Sun from the Earth. This agreed with the value of 8.86” deduced by Leon Foucault and led to a debate with Le Verrier. He moved to the United States in 1873 working briefly in the Census Bureau and later at a naval observatory in Washington. Poor health forced him back to German but he returned and moved to Pennsylvania. He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neudietendorf
Neudietendorf (''New Dietendorf'') is a village and a former municipality in the district of Gotha, in Thuringia, central Germany. Since 1 December 2009, it has been part of the municipality Nesse-Apfelstädt, of which it is an ''Ortschaft''. The former municipality also contained the village and current ''Ortschaft'' Kornhochheim. August 2015. Since the concession signed by Duke Friedrich III on 27 March 1764, it has been the seat of a congregation of the |
Peter Andreas Hansen
Peter Andreas Hansen (born 8 December 1795, Tønder, Schleswig, Denmark; died 28 March 1874, Gotha, Thuringia, Germany) was a Danish-born German astronomer. Biography The son of a goldsmith, Hansen learned the trade of a watchmaker at Flensburg, and exercised it at Berlin and Tønder, 1818–1820. He had, however, long been a student of science; and Dr Dircks, a physician practising at Tønder, prevailed with his father to send him in 1820 to Copenhagen, where he won the patronage of H.C. Schumacher and attracted the personal notice of King Frederick VI. The Danish survey was then in progress, and he acted as Schumacher's assistant in work connected with it, chiefly at the new observatory of Altona, from 1821–1825. Thence he passed on to Gotha as director of the Gotha Observatory; nor could he be tempted to relinquish the post by successive invitations to replace F.G.W. Struve at Dorpat in 1829, Friedrich Wilhelm August Argelander at Helsinki in 1837, and F.W. Bessel at Kö ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transit Of Venus
frameless, upright=0.5 A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During a transit, Venus can be seen from Earth as a small black dot moving across the face of the Sun. The duration of such transits is usually several hours (the transit of 2012 lasted 6 hours and 40 minutes). A transit is similar to a solar eclipse by the Moon. While the diameter of Venus is more than three times that of the Moon, Venus appears smaller, and travels more slowly across the face of the Sun, because it is much farther away from Earth. Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that generally repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years. The periodicity is a reflection of the fact that the orbital periods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits the Sun, from a maximum (aphelion) to a minimum (perihelion) and back again once each year. The astronomical unit was originally conceived as the average of Earth's aphelion and perihelion; however, since 2012 it has been defined as exactly (see below for several conversions). The astronomical unit is used primarily for measuring distances within the Solar System or around other stars. It is also a fundamental component in the definition of another unit of astronomical length, the parsec. History of symbol usage A variety of unit symbols and abbreviations have been in use for the astronomical unit. In a 1976 resolution, the International Astronomical Union (IAU) had used the symbol ''A'' to denote a length equal to the astronomical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Léon Foucault
Jean Bernard Léon Foucault (, ; ; 18 September 1819 – 11 February 1868) was a French physicist best known for his demonstration of the Foucault pendulum, a device demonstrating the effect of Earth's rotation. He also made an early measurement of the speed of light, discovered eddy currents, and is credited with naming the gyroscope. Early years The son of a publisher, Foucault was born in Paris on 18 September 1819. After an education received chiefly at home, he studied medicine, which he abandoned in favour of physics due to a blood phobia. He first directed his attention to the improvement of Louis Daguerre's photographic processes. For three years he was experimental assistant to Alfred Donné (1801–1878) in his course of lectures on microscopic anatomy. With Hippolyte Fizeau he carried out a series of investigations on the intensity of the light of the sun, as compared with that of carbon in the arc lamp, and of lime in the flame of the oxyhydrogen blowpipe; on the int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urbain Le Verrier
Urbain Jean Joseph Le Verrier FRS (FOR) HFRSE (; 11 March 1811 – 23 September 1877) was a French astronomer and mathematician who specialized in celestial mechanics and is best known for predicting the existence and position of Neptune using only mathematics. The calculations were made to explain discrepancies with Uranus's orbit and the laws of Kepler and Newton. Le Verrier sent the coordinates to Johann Gottfried Galle in Berlin, asking him to verify. Galle found Neptune in the same night he received Le Verrier's letter, within 1° of the predicted position. The discovery of Neptune is widely regarded as a dramatic validation of celestial mechanics, and is one of the most remarkable moments of 19th-century science. Biography Early years Le Verrier was born at Saint-Lô, Manche, France, in a modest bourgeois family, his parents being, Louis-Baptiste Le Verrier and Marie-Jeanne-Josephine-Pauline de Baudre. He studied at École Polytechnique. He briefly studied chemistry und ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asaph Hall
Asaph Hall III (October 15, 1829 – November 22, 1907) was an American astronomer who is best known for having discovered the two moons of Mars, Deimos and Phobos, in 1877. He determined the orbits of satellites of other planets and of double stars, the rotation of Saturn, and the mass of Mars. Biography Hall was born in Goshen, Connecticut, the son of Asaph Hall II (1800–42), a clockmaker, and Hannah Palmer (1804–80). His paternal grandfather Asaph Hall I (June 11, 1735 – March 29, 1800) was a Revolutionary War officer and Connecticut state legislator. His father died when he was 13, leaving the family in financial difficulty, so Hall left school at 16 to become an apprentice to a carpenter. He later enrolled at the New-York Central College in McGrawville, New York, where he studied mathematics. There he took classes from an instructor of geometry and German, Angeline Stickney. In 1856 they married. In 1856, Hall took a job at the Harvard College Observatory in Cambrid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prospect Hill Cemetery (Washington, D , a historic German-American cemetery
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Prospect Hill Cemetery may refer to: *Prospect Hill Cemetery (Millis, Massachusetts), listed on the NRHP in Massachusetts *Prospect Hill Cemetery (Omaha, Nebraska), a pioneer cemetery in Omaha, Nebraska *Prospect Hill Cemetery, location of Prospect Hill Cemetery Building, Guilderland, New York, listed on the National Register of Historic Places in Albany County, New York *Prospect Hill Cemetery (York, Pennsylvania) *Prospect Hill Cemetery (Brattleboro, Vermont) in Windham County, Vermont *Prospect Hill Cemetery (Washington, D.C.) Prospect Hill Cemetery, also known as the German Cemetery, is a historic Germans, German-United States, American cemetery founded in 1858 and located at 2201 North Capitol Street in Washington, D.C. From 1886 to 1895, the Prospect Hill Cemetery bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1817 Births
Events January–March * January 1 – Sailing through the Sandwich Islands, Otto von Kotzebue discovers New Year Island. * January 19 – An army of 5,423 soldiers, led by General José de San Martín, starts crossing the Andes from Argentina, to liberate Chile and then Peru. * January 20 – Ram Mohan Roy and David Hare found Hindu College, Calcutta, offering instructions in Western languages and subjects. * February 12 – Battle of Chacabuco: The Argentine–Chilean patriotic army defeats the Spanish. * March 3 ** President James Madison vetoes John C. Calhoun's Bonus Bill. ** The U.S. Congress passes a law to split the Mississippi Territory, after Mississippi drafts a constitution, creating the Alabama Territory, effective in August. * March 4 – James Monroe is sworn in as the fifth President of the United States. * March 21 – The flag of the Pernambucan Revolt is publicly blessed by the dean of Recife Cathedral, Brazil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1881 Deaths
Events January–March * January 1– 24 – Siege of Geok Tepe: Russian troops under General Mikhail Skobelev defeat the Turkomans. * January 13 – War of the Pacific – Battle of San Juan and Chorrillos: The Chilean army defeats Peruvian forces. * January 15 – War of the Pacific – Battle of Miraflores: The Chileans take Lima, capital of Peru, after defeating its second line of defense in Miraflores. * January 24 – William Edward Forster, chief secretary for Ireland, introduces his Coercion Bill, which temporarily suspends habeas corpus so that those people suspected of committing an offence can be detained without trial; it goes through a long debate before it is accepted February 2. * January 25 – Thomas Edison and Alexander Graham Bell form the Oriental Telephone Company. * February 13 – The first issue of the feminist newspaper ''La Citoyenne'' is published by Hubertine Auclert. * February 16 – The Canadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
