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Great Paris Exhibition Telescope Of 1900
The Great Paris Exhibition Telescope of 1900, with an objective lens of in diameter, was the largest refracting telescope ever constructed. It was built as the centerpiece of the Paris Universal Exhibition of 1900. Its construction was instigated in 1892 by François Deloncle (1856–1922), a member of the French Chambre des Députés. Since it was built for exhibit purposes within a large metropolis, and its design made it difficult to aim at astronomical objects, it was not suited for scientific use. When the year-long exposition was over, its builders were unable to sell it. It was ultimately broken up for scrap; the lenses are still stored away at the Paris Observatory. Design The telescope had two interchangeable objective lenses (for visual and photographic use respectively) in diameter, with a focal length of . Due to its extremely large size, the telescope was mounted in a fixed horizontal position. Light from astronomical objects was redirected into the optical tub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective (optics)
In optical engineering, the objective is the optical element that gathers light from the object being observed and focuses the light rays to produce a real image. Objectives can be a single lens or mirror, or combinations of several optical elements. They are used in microscopes, binoculars, telescopes, cameras, slide projectors, CD players and many other optical instruments. Objectives are also called object lenses, object glasses, or objective glasses. Microscope objectives The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube. The objective itself is usually a cylinder containing one or more lenses that are typically made of glass; its function is to collect light from the sample. Magnification One of the most important prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Théophile Moreux
Théophile Moreux (20 November 1867 – 13 July 1954) was a French astronomer and meteorologist. Life Moreux was born at Argent-sur-Sauldre, Cher on 20 November 1867. He initiated the Bourges Observatory at the seminary St Célestin at Bourges, where he was a professor of science and mathematics. He observed surface features of the Moon and Mars. He published star maps and investigated the possibility of life on other planets and moons. He was critical of Percival Lowell's theory of intelligent life on Mars. During 1922 he published a review of astronomical theories and techniques (''La Revue Du Ciel''). Moreux died at Bourges Bourges () is a commune in central France on the river Yèvre. It is the capital of the department of Cher, and also was the capital city of the former province of Berry. History The name of the commune derives either from the Bituriges, t ... on 13 July 1954. The Moreux crater on Mars was named in his honor. Works * External links biograph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1900s In Paris
Nineteen or 19 may refer to: * 19 (number), the natural number following 18 and preceding 20 * one of the years 19 BC, AD 19, 1919, 2019 Films * ''19'' (film), a 2001 Japanese film * ''Nineteen'' (film), a 1987 science fiction film Music * 19 (band), a Japanese pop music duo Albums * ''19'' (Adele album), 2008 * ''19'', a 2003 album by Alsou * ''19'', a 2006 album by Evan Yo * ''19'', a 2018 album by MHD * ''19'', one half of the double album ''63/19'' by Kool A.D. * ''Number Nineteen'', a 1971 album by American jazz pianist Mal Waldron * ''XIX'' (EP), a 2019 EP by 1the9 Songs * "19" (song), a 1985 song by British musician Paul Hardcastle. * "Nineteen", a song by Bad4Good from the 1992 album ''Refugee'' * "Nineteen", a song by Karma to Burn from the 2001 album ''Almost Heathen''. * "Nineteen" (song), a 2007 song by American singer Billy Ray Cyrus. * "Nineteen", a song by Tegan and Sara from the 2007 album '' The Con''. * "XIX" (song), a 2014 song by Slipknot. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1900 In France
Events from the year 1900 in France. Incumbents *President: Émile Loubet *President of the Council of Ministers: Pierre Waldeck-Rousseau Events * 31 March – The length of a workday for women and children is limited to 11 hours by law. * 1 April – Every French policeman is assigned to carry a gun. * 14 April – Paris World Exhibition opens. * 21 April – Battle of Kousséri takes place in Chad, linking all French possessions in Western Africa. * 27 June – Treaty of Paris is signed between the Spanish Empire and the French Empire by which Río Muni is relieved of all conflicting claims. * 19 July – The first line of the Métro is inaugurated in Paris. * First Michelin Guide published. Arts and literature * 2 February – First performance of Gustave Charpentier's opera, ''Louise''. * 21 November – Claude Monet's paintings shown at Gallery Durand-Ruel in Paris Sport * 14 May–28 October - Olympic Games held in Paris. Births January to March * 3 January – Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Telescopes
An optical telescope is a telescope that gathers and focuses light mainly from the visible part of the electromagnetic spectrum, to create a magnified image for direct visual inspection, to make a photograph, or to collect data through electronic image sensors. There are three primary types of optical telescope: * Refracting telescopes, which use lenses and less commonly also prisms (dioptrics) * Reflecting telescopes, which use mirrors ( catoptrics) * Catadioptric telescopes, which combine lenses and mirrors An optical telescope's ability to resolve small details is directly related to the diameter (or aperture) of its objective (the primary lens or mirror that collects and focuses the light), and its light-gathering power is related to the area of the objective. The larger the objective, the more light the telescope collects and the finer detail it resolves. People use optical telescopes (including monoculars and binoculars) for outdoor activities such as observation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Largest Optical Telescopes Historically
Telescopes have grown in size since they first appeared around 1608. The following tables list the increase in size over the years. Different technologies can and have been used to build telescopes, which are used to magnify distant views especially in astronomy. By overall aperture The following is a list of largest single mount optical telescopes sorted by total objective diameter (''aperture''), including segmented and multi-mirror configurations. It is a historical list, with the instruments listed in chronological succession by objective size. By itself, the diameter of the primary optics can be a poor measure of a telescope's historical or scientific significance; for example, William Parsons, 3rd Earl of Rosse's 72-inch (1.8 m) reflecting telescope did not perform as well (i.e. gather as much light) as the smaller silvered glass mirror telescopes that succeeded it because of the poor performance of its speculum metal mirror. By historical significance Chronolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Largest Optical Refracting Telescopes
Refracting telescopes use a lens to focus light. The largest refracting telescope in the world is the Yerkes Observatory 40 inch (102 cm) refractor, used for astronomical and scientific observation for over a century. The Swedish 1-m Solar Telescope, which has an actual lens diameter of 43 inches, is technically then larger than the lens of the Yerkes, but only 39 inches are clear for the aperture, and is used today for solar observations .The next largest refractor telescopes are the James Lick telescope, and the Meudon Great Refractor. Most are classical great refractors, which used achromatic doublets on an equatorial mount. However, other large refractors include a 21st-century solar telescope which is not directly comparable because it uses a single element non-achromatic lens, and the short-lived Great Paris Exhibition Telescope of 1900. It used a 78-inch (200 cm) Focault siderostat for aiming light into the Image-forming optical system part of the telescope, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Pollution
Light pollution is the presence of unwanted, inappropriate, or excessive use of artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting, during the day or night. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind of pollution, but also as a contributor to the wider, collective impact of various sources of pollution. Although this type of pollution can exist throughout the day, its effects are magnified during the night with the contrast of darkness. It has been estimated that 83 percent of the world's people live under light-polluted skies and that 23 percent of the world's land area is affected by skyglow. The area affected by artificial illumination continues to increase. A major side-effect of urbanization, light pollution is blamed for compromising health, disrupting ecosystems, and spoiling aesthetic environments. Globally, it has incr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Ex Telescope Cartoon
Great may refer to: Descriptions or measurements * Great, a relative measurement in physical space, see Size * Greatness, being divine, majestic, superior, majestic, or transcendent People * List of people known as "the Great" *Artel Great (born 1981), American actor Other uses * ''Great'' (1975 film), a British animated short about Isambard Kingdom Brunel * ''Great'' (2013 film), a German short film * Great (supermarket), a supermarket in Hong Kong * GReAT, Graph Rewriting and Transformation, a Model Transformation Language * Gang Resistance Education and Training Gang Resistance Education And Training, abbreviated G.R.E.A.T., provides a school-based, police officer instructed program that includes classroom instruction and various learning activities. Their intention is to teach the students to avoid gang ..., or GREAT, a school-based and police officer-instructed program * Global Research and Analysis Team (GReAT), a cybersecurity team at Kaspersky Lab *'' Great!'', a 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strand Magazine
''The Strand Magazine'' was a monthly British magazine founded by George Newnes, composed of short fiction and general interest articles. It was published in the United Kingdom from January 1891 to March 1950, running to 711 issues, though the first issue was on sale well before Christmas 1890. Its immediate popularity is evidenced by an initial sale of nearly 300,000. Sales increased in the early months, before settling down to a circulation of almost 500,000 copies a month, which lasted well into the 1930s. It was edited by Herbert Greenhough Smith from 1891 to 1930. The popularity of Sherlock Holmes became widespread after first appearing in the magazine in 1891. The magazine's original offices were on Burleigh Street off The Strand, London. It was revived in 1998 as a quarterly magazine. Publication history ''The Strand Magazine'' was founded by George Newnes in 1890, and its first edition was dated January 1891. The magazine's original offices were located on Burleigh S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Nebula
A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regions, such as in the "Pillars of Creation" in the Eagle Nebula. In these regions, the formations of gas, dust, and other materials "clump" together to form denser regions, which attract further matter, and eventually will become dense enough to form stars. The remaining material is then thought to form planets and other planetary system objects. Most nebulae are of vast size; some are hundreds of light-years in diameter. A nebula that is visible to the human eye from Earth would appear larger, but no brighter, from close by. The Orion Nebula, the brightest nebula in the sky and occupying an area twice the angular diameter of the full Moon, can be viewed with the naked eye but was missed by early astronomers. Although denser than the space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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