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Bureau International De L'Heure
The International Time Bureau (, abbreviated BIH), seated at the Paris Observatory, was the international bureau responsible for combining different measurements of Universal Time. The bureau also played an important role in the research of time keeping and related fields: Earth rotation, reference frames, and atomic time. In 1987 the responsibilities of the bureau were taken over by the International Bureau of Weights and Measures (BIPM) and the International Earth Rotation and Reference Systems Service (IERS). History The creation of the BIH was decided upon during the 1912 ''Conférence internationale de l'heure radiotélégraphique''. The following year an attempt was made to regulate the international status of the bureau through the creation of an international convention. However, the convention wasn't ratified by its member countries due to the outbreak of World War I. In 1919, after the war, it was decided to make the bureau the executive body of the ''International Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paris Observatory
The Paris Observatory (, ), a research institution of the Paris Sciences et Lettres University, is the foremost astronomical observatory of France, and one of the largest astronomical centres in the world. Its historic building is on the Left Bank of the Seine in central Paris, but most of the staff work on a satellite campus in Meudon, a suburb southwest of Paris. The Paris Observatory was founded in 1667. Construction was completed by the early 1670s and coincided with a major push for increased science, and the founding of the Royal Academy of Sciences. King Louis XIV's minister of finance organized a "scientific powerhouse" to increase understanding of astronomy, maritime navigation, and science in general. Through the centuries the Paris Observatory has continued in support of astronomical activities, and in the 21st century connects multiple sites and organizations, supporting astronomy and science, past and present. Constitution Administratively, it is a '' grand étab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benjamin Baillaud
Édouard Benjamin Baillaud (; 14 February 1848 – 8 July 1934) was a French astronomer. Biography Born in Chalon-sur-Saône, Baillaud studied at the École Normale Supérieure (1866-1869) and the University of Paris. He worked as an assistant at the Paris Observatory beginning in 1872. Later he was director of the Toulouse Observatory from 1878 to 1907, during much of this time serving as Dean of the University of Toulouse Faculty of Science. He greatly expanded the observatory and enthusiastically supported the ''Carte du Ciel'' project. He specialized in celestial mechanics, in particular the motions of the satellites of Saturn. In 1903, the observatory took over a facility on the Pic du Midi in the Pyrenees that had been founded by amateurs in the 1850s with the goal of putting a telescope there. However, the height of 2865 metres (9400 feet) posed formidable logistical challenges and the ambition had remained unrealised though a meteorological observatory had ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standards Organizations In France
Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object that bears a defined relationship to a unit of measure used for calibration of measuring devices * Standard (timber unit), an obsolete measure of timber used in trade * Breed standard (also called bench standard), in animal fancy and animal husbandry * BioCompute Standard, a standard for next generation sequencing * ''De facto'' standard, product or system with market dominance * Gold standard, a monetary system based on gold; also used metaphorically for the best of several options, against which the others are measured * Internet Standard, a specification ratified as an open standard by the Internet Engineering Task Force * Learning standards, standards applied to education content * Standard displacement, a naval term describing the wei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth's Rotation
Earth's rotation or Earth's spin is the rotation of planet Earth around its own Rotation around a fixed axis, axis, as well as changes in the orientation (geometry), orientation of the rotation axis in space. Earth rotates eastward, in prograde motion. As viewed from the northern polar star Polaris, Earth turns counterclockwise. The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where Earth's axis of rotation meets its surface. This point is distinct from Earth's north magnetic pole. The South Pole is the other point where Earth's axis of rotation intersects its surface, in Antarctica. Earth rotates once in about 24 hours with respect to the Sun, but once every 23 hours, 56 minutes and 4 seconds with respect to other distant stars (#Stellar and sidereal day, see below). Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal acceleration, tidal effects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frame Of Reference
In physics and astronomy, a frame of reference (or reference frame) is an abstract coordinate system, whose origin (mathematics), origin, orientation (geometry), orientation, and scale (geometry), scale have been specified in physical space. It is based on a set of reference points, defined as point (geometry), geometric points whose position (geometry), position is identified both mathematically (with numerical coordinate values) and physically (signaled by conventional markers). An important special case is that of ''inertial reference frames'', a stationary or uniformly moving frame. For ''n'' dimensions, reference points are sufficient to fully define a reference frame. Using Cartesian coordinate system, rectangular Cartesian coordinates, a reference frame may be defined with a reference point at the origin and a reference point at one unit distance along each of the ''n'' coordinate Cartesian coordinate system, axes. In Theory of relativity, Einsteinian relativity, referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Object
An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists within the observable universe. In astronomy, the terms ''object'' and ''body'' are often used interchangeably. However, an astronomical body or celestial body is a single, tightly bound, contiguous entity, while an astronomical or celestial ''object'' is a complex, less cohesively bound structure, which may consist of multiple bodies or even other objects with substructures. Examples of astronomical objects include planetary systems, star clusters, nebulae, and galaxies, while asteroids, moons, planets, and stars are astronomical bodies. A comet may be identified as both a body and an object: It is a ''body'' when referring to the frozen nucleus of ice and dust, and an ''object'' when describing the entire comet with its diffuse coma and tail. History Astronomical objects such as stars, planets, nebulae, aster ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernard Guinot
Bernard René Guinot (1925–2017) was a French astronomer. He is known for his contributions to the establishment of ''temps atomique international'' (TAI) and the geodetic reference system used in satellite navigation. Biography From 1945 to 1952, Guinot served as an officer in the '' Messageries Maritimes''. In 1952 he became an astronomer at the Paris Observatory, where he worked with André Danjon on applications and further developments of the Danjon prismatic astrolabe. The applications were especially concerned with precise determinations of polar motions and variations in the Earth's rotation. In 1958 with a dissertation on applications of the Danjon astrolabe, Guinot obtained his doctorate from the University of Paris. He continued his employment as an astronomer at the Paris Observatory until 1990. From 1984 to 1992 he was a ''physicien principal'' (senior physicist), and then a consultant, at the Bureau international des poids et mesures (BIPM). Guinot served as a co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicolas Stoyko
Nicolas Stoyko or Nikolaï Mikhaïlovitch Stoyko (Russian language, Russian: Николай Михайлович Стойко, ''Nikolaï Mikhaïlovitch Stoïko''; Ukrainian language, Ukrainian: Микола Михайлович Стойко, ''Mykola Mikhaïlovitch Stoïko'', 1894–1976) was a Ukrainian-French astronomer, known for his research on the precise measurement of time and the rate of rotation of planet Earth. Biography Stoyko studied at the Imperial Novorossiya University (now Odesa University) before working from 1914 to 1916 as a volunteer at the Odesa Astronomical Observatory, directed at the time by Aleksandr Yakovlevich Orlov. After graduating with a degree in mathematical sciences in 1916, Stoyko served in the Russian army from 1916 to 1918. He was certified as ''agrégé de mathématiques'' in 1920. Because of the chaos caused by the Russian Civil War, Stoyko was unemployed and immigrated to Bulgaria to find work. For three years, he taught at a boys' secondary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guillaume Bigourdan
Camille Guillaume Bigourdan (; 6 April 1851 – 28 February 1932) was a French astronomer. Personal life Bigourdan was born at Sistels, Tarn-et-Garonne to Pierre Bigourdan and Jeanne Carrière. When his teachers and local curate recognised his intelligence, he was transferred to a local boarding school in Valence d’Agen, where he excelled. In 1870, he received his Baccalauréat with mention of "Assez Bien". He married Marie Mélanie Sophie Mouchez, the eldest daughter of Admiral Amédée Mouchez. Together, the two had nine children. The entire family, including the Mouchez cousins, would frequently vacation in Sistels until the outbreak of the First World War, after which Bigourdan would vacation alone. During these vacations, he would farm his land and visit former classmates. He was fluent in Occitan, and spoke it when in Sistels. Academic and scientific career Bigourdan studied at the University of Toulouse from 1870, where he received a physics degree in 1874 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels, Belgium and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. the Union had 85 national members and 12,734 individual members, spanning 90 countries and territories. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Time
Universal Time (UT or UT1) is a time standard based on Earth's rotation. While originally it was mean solar time at 0° longitude, precise measurements of the Sun are difficult. Therefore, UT1 is computed from a measure of the Earth's angle with respect to the International Celestial Reference Frame (ICRF), called the Earth Rotation Angle (ERA, which serves as the replacement for Greenwich Mean Sidereal Time). UT1 is the same everywhere on Earth. UT1 is required to follow the relationship :ERA = 2π(0.7790572732640 + 1.00273781191135448'' · Tu'') radians where ''Tu'' = ( Julian UT1 date − 2451545.0). History Prior to the introduction of standard time, each municipality throughout the clock-using world set its official clock, if it had one, according to the local position of the Sun (see solar time). This served adequately until the introduction of rail travel in Britain, which made it possible to travel fast enough over sufficiently long distances as to req ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
