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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] |
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] |
Refracting Telescope
A refracting telescope (also called a refractor) is a type of optical telescope that uses a lens (optics), lens as its objective (optics), objective to form an image (also referred to a dioptrics, dioptric telescope). The refracting telescope design was originally used in spyglasses and astronomy, astronomical telescopes but is also used for long-focus lens, long-focus camera lenses. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes, the refracting telescope has been superseded by the reflecting telescope, which allows larger apertures. A refractor's magnification is calculated by dividing the focal length of the objective lens by that of the eyepiece. Refracting telescopes typically have a lens at the front, then a optical train, long tube, then an eyepiece or instrumentation at the rear, where the telescope view comes to focus. Originally, telescopes had an objective of one element, but a century later, tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded in 1919 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. As of 2018, the Union had over 13,700 individual members, spanning 90 countries, and 82 national members. 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] |
Daylight Saving Time
Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typically by one hour) during warmer months so that darkness falls at a later clock time. The typical implementation of DST is to set clocks forward by one hour in the spring ("spring forward"), and to set clocks back by one hour in the fall ("fall back") to return to standard time. As a result, there is one 23-hour day in early spring and one 25-hour day in the middle of autumn. The idea of aligning waking hours to daylight hours to conserve candles was first proposed in 1784 by U.S. polymath Benjamin Franklin. In a satirical letter to the editor of ''The Journal of Paris'', Franklin suggested that waking up earlier in the summer would economize on candle usage; and calculated considerable savings. In 1895, New Zealand entomologist and astronome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Bertha (Howitzer)
The 42-centimetre 14 L/12 (short naval cannon), or ''Minenwerfer-Gerät'' (M-Gerät), popularly known by the nickname Big Bertha, was a German siege howitzer built by Krupp AG in Essen, Germany and fielded by the Imperial German Army from 1914 to 1918. The had a calibre barrel, making it one of the largest artillery pieces ever fielded. The designed in 1911 as an iteration of earlier super-heavy German siege guns intended to break modern fortresses in France and Belgium and entered production in 1912. Test firing began in early 1914 and the gun was estimated to be finished by October 1914. When the First World War broke out, the two guns, still prototypes, were sent to Liège, Belgium, and destroyed Forts Pontisse and Loncin. German soldiers bestowed the gun with the nickname "Big Bertha", which then spread through German newspapers to the Allies, who used it as a nickname for all super-heavy German artillery. The Paris Gun, a railway gun used to bomb Paris in 1918, has h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Howitzer
A howitzer () is a long- ranged weapon, falling between a cannon (also known as an artillery gun in the United States), which fires shells at flat trajectories, and a mortar, which fires at high angles of ascent and descent. Howitzers, like other artillery equipment, are usually organized in a group called a battery. Howitzers, together with long-barreled guns, mortars, and rocket artillery, are the four basic types of modern artillery. Mortars fire at angles of elevation greater than 45°, and are useful for mountain warfare because the projectile could go over obstacles. Cannons fire at low angles of elevation (<45°), and the projectile lands much faster at its target than it would in the case of a mortar. But the cannon is not useful if there is an obstacle like a hill/wall in front of its target. Etymology The English word ''howitzer'' comes from the Czech word , from , 'crowd', and is in turn a borrowing from the Middle High German word or (mode ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz Ferdin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eiffel Tower
The Eiffel Tower ( ; french: links=yes, tour Eiffel ) is a wrought-iron lattice tower on the Champ de Mars in Paris, France. It is named after the engineer Gustave Eiffel, whose company designed and built the tower. Locally nicknamed "''La dame de fer''" (French for "Iron Lady"), it was constructed from 1887 to 1889 as the centerpiece of the 1889 World's Fair. Although initially criticised by some of France's leading artists and intellectuals for its design, it has since become a global cultural icon of France and one of the most recognisable structures in the world. The Eiffel Tower is the most visited monument with an entrance fee in the world: 6.91 million people ascended it in 2015. It was designated a '' monument historique'' in 1964, and was named part of a UNESCO World Heritage Site ("Paris, Banks of the Seine") in 1991. The tower is tall, about the same height as an 81- building, and the tallest structure in Paris. Its base is square, measuring on each sid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Signal
A time signal is a visible, audible, mechanical, or electronic signal used as a reference to determine the time of day. Church bells or voices announcing hours of prayer gave way to automatically operated chimes on public clocks; however, audible signals (even signal guns) have limited range. Busy seaports used a visual signal, the dropping of a ball, to allow mariners to check the chronometers used for navigation. The advent of electrical telegraphs allowed widespread and precise distribution of time signals from central observatories. Railways were among the first customers for time signals, which allowed synchronization of their operations over wide geographic areas. Dedicated radio time signal stations transmit a signal that allows automatic synchronization of clocks, and commercial broadcasters still include time signals in their programming. Today, global navigation satellite systems (GNSS) radio signals are used to precisely distribute time signals over much of the world ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Time Bureau
The International Time Bureau (french: Bureau International de l'Heure, 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 exec ... [...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 a modern 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 long distances to require continuous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Société Astronomique De France
The Société astronomique de France (SAF; ), the French astronomical society, is a non-profit association in the public interest organized under French law (Association loi de 1901). Founded by astronomer Camille Flammarion in 1887, its purpose is to promote the development and practice of astronomy. History SAF was established by Camille Flammarion and a group of 11 persons on 28 January 1887 in Flammarion's apartment at 16 rue Cassini, 75014 Paris, close to the Paris Observatory. Open to all, SAF includes both professional and amateur astronomers as members, from France and abroad.Ferlet R. (2003) "The Société Astronomique de France in the Astronomical Landscape: Evolution and Prospects." In: ''Organizations and Strategies in Astronomy''. Astrophysics and Space Science Library, vol 296. Springer, Dordrecht. Its objective was defined at the time of its establishment as: "A Society is founded with the aim to bring together people involved practically or theoretically in As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
