George W. Ritchey
George Willis Ritchey (December 31, 1864 – November 4, 1945) was an American optician and telescope maker and astronomer born at Tuppers Plains, Ohio. Ritchey was educated as a furniture maker. He coinvented the Ritchey–Chrétien (R–C) reflecting telescope along with Henri Chrétien. The R-C prescription remains the predominant optical design for telescopes and has since been used for the majority of major ground-based and space-based telescopes. He worked closely with George Ellery Hale, first at Yerkes Observatory and later at Mt. Wilson Observatory. He played a major role in designing the mountings and making the mirrors of the Mt. Wilson and telescopes. Hale and Ritchey had a falling out in 1919, and Ritchey eventually went to Paris where he promoted the construction of very large telescopes. He returned to America in 1930 and obtained a contract to build a Ritchey-Chrétien telescope for the U.S. Naval Observatory. This last telescope produced by Ritchey rem ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mount Wilson Observatory
The Mount Wilson Observatory (MWO) is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles. The observatory contains two historically important telescopes: the Hooker telescope, which was the largest aperture telescope in the world from its completion in 1917 to 1949, and the 60-inch telescope which was the largest operational telescope in the world when it was completed in 1908. It also contains the Snow solar telescope completed in 1905, the 60 foot (18 m) solar tower completed in 1908, the 150 foot (46 m) solar tower completed in 1912, and the CHARA array, built by Georgia State University, which became fully operational in 2004 and was the largest optical interferometer in the world at its completion. Due to the inversion layer that traps warm air and smog over Los Angeles, Mount Wilson has steadier air than any other location in Nor ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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United States Naval Observatory Flagstaff Station
The United States Naval Observatory Flagstaff Station (NOFS), is an astronomical observatory near Flagstaff, Arizona, US. It is the national dark-sky observing facility under the United States Naval Observatory (USNO). NOFS and USNO combine as the Celestial Reference Frame manager for the U.S. Secretary of Defense. General information The Flagstaff Station is a command which was established by USNO (due to a century of eventually untenable light encroachment in Washington, D.C.) at a site west of Flagstaff, Arizona in 1955, and has positions for primarily operational scientists (astronomers and astrophysicists), optical and mechanical engineers, and support staff. NOFS science supports every aspect of positional astronomy to some level, providing national support and beyond. Work at NOFS covers the gamut of astrometry and astrophysics in order to facilitate its production of accurate/precise astronomical catalogs. Also, owing to the celestial dynamics (and relativistic ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1945 Deaths
1945 marked the end of World War II and the fall of Nazi Germany and the Empire of Japan. It is also the only year in which Nuclear weapon, nuclear weapons Atomic bombings of Hiroshima and Nagasaki, have been used in combat. Events Below, the events of World War II have the "WWII" prefix. January * January 1 – WWII: ** Nazi Germany, Germany begins Operation Bodenplatte, an attempt by the ''Luftwaffe'' to cripple Allies of World War II, Allied air forces in the Low Countries. ** Chenogne massacre: German prisoners are allegedly killed by American forces near the village of Chenogne, Belgium. * January 6 – WWII: A German offensive recaptures Esztergom, Kingdom of Hungary (1920–1946), Hungary from the Russians. * January 12 – WWII: The Soviet Union begins the Vistula–Oder Offensive in Eastern Europe, against the German Army (Wehrmacht), German Army. * January 13 – WWII: The Soviet Union begins the East Prussian Offensive, to eliminate German forces in East Pruss ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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1864 Births
Events January–March * January 13 – American songwriter Stephen Foster ("Oh! Susanna", "Old Folks at Home") dies aged 37 in New York City, leaving a scrap of paper reading "Dear friends and gentle hearts". His parlor song " Beautiful Dreamer" is published in March. * January 16 – Denmark rejects an Austrian-Prussian ultimatum to repeal the Danish Constitution, which says that Schleswig-Holstein is part of Denmark. * January 21 – New Zealand Wars: The Tauranga campaign begins. * February – John Wisden publishes '' The Cricketer's Almanack for the year 1864'' in England; it will go on to become the major annual cricket reference publication. * February 1 – Danish-Prussian War (Second Schleswig War): 57,000 Austrian and Prussian troops cross the Eider River into Denmark. * February 15 – Heineken brewery founded in Netherlands. * February 17 – American Civil War: The tiny Confederate hand-propelled submarine ''H. L. Hunl ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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List Of Astronomical Instrument Makers
The following is a list of astronomical instrument makers, along with lifespan and country of work, if available. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z See also * History of the telescope * List of largest optical reflecting telescopes * List of largest optical refracting telescopes * List of observatory codes * List of Russian astronomers and astrophysicists * List of telescope types * Space telescope * Timeline of telescopes, observatories, and observing technology External links {{DEFAULTSORT:Astronomical Instrument Makers Technology-related lists Instrument makers Lists of manufacturers Astronomical instruments Astronomical instruments include: *Alidade *Armillary sphere * Astrarium *Astrolabe *Astronomical clock *the Antikythera mechanism, an astronomical clock *Blink comparator * Bolometer *the Canterbury Astrolabe Quadrant *Celatone *Celestial sph ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terrestrial planet with a thin atmosphere (less than 1% that of Earth's), and has a crust primarily composed of elements similar to Earth's crust, as well as a core made of iron and nickel. Mars has surface features such as impact craters, valleys, dunes and polar ice caps. It has two small and irregularly shaped moons, Phobos (moon), Phobos and Deimos (moon), Deimos. Some of the most notable surface features on Mars include Olympus Mons, the largest volcano and List of tallest mountains in the Solar System, highest known mountain in the Solar System and Valles Marineris, one of the largest canyons in the Solar System. The North Polar Basin (Mars), Borealis basin in the Northern Hemisphere covers approximately 40% of the planet and may be a la ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Impact Crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo Program and small, simple, bowl-shaped depressions in the lunar regolith to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io and Titan, visible impact craters are less common because they become eroded ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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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]   |
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Yerkes Observatory
Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Ownership was transferred to the non-profit Yerkes Future Foundation (YFF) in May 2020, which began restoration and renovation of the historic building and grounds. Re-opening for public tours and programming began May 27, 2022. The observatory, often called "the birthplace of modern astrophysics," was founded in 1892 by astronomer George Ellery Hale and financed by businessman Charles T. Yerkes. It represented a shift in the thinking about observatories, from their being mere housing for telescopes and observers, to the early-20th-century concept of observation equipment integrated with laboratory space for physics and chemistry analysis. The observatory's main dome houses a doublet lens refracting telescope, the largest refractor ever ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tuppers Plains, Ohio
Tuppers Plains is a census-designated place on the boundary of the Olive and Orange townships of Meigs County, Ohio, United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie .... Education Public education in the community of Tuppers Plains is provided by the Eastern Local School District. Campuses serving the community includEastern Elementary School (Grades K-8) and Eastern High Schoolbr> (Grades 9-12). References Unincorporated communities in Ohio Unincorporated communities in Meigs County, Ohio Census-designated places in Ohio {{MeigsCountyOH-geo-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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George Ellery Hale
George Ellery Hale (June 29, 1868 – February 21, 1938) was an American solar astronomer, best known for his discovery of magnetic fields in sunspots, and as the leader or key figure in the planning or construction of several world-leading telescopes; namely, the 40-inch refracting telescope at Yerkes Observatory, 60-inch Hale reflecting telescope at Mount Wilson Observatory, 100-inch Hooker reflecting telescope at Mount Wilson, and the 200-inch Hale reflecting telescope at Palomar Observatory. He also played a key role in the foundation of the International Union for Cooperation in Solar Research and the National Research Council, and in developing the California Institute of Technology into a leading research university. Early life and education George Ellery Hale was born on June 29, 1868, in Chicago, Illinois, to William Ellery Hale and Mary Browne.Adams 1939, p. 181. He is descended from Thomas Hale of Watton-on-Stone, Hertfordshire, England, whose son emigrate ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |