Laurent Cassegrain
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Laurent Cassegrain
Laurent Cassegrain (; – 1 September 1693) was a Catholic priest who is notable as the probable inventor of the Cassegrain reflector, a folded two-mirror reflecting telescope design. Biography Laurent Cassegrain was born in the region of Chartres around 1629 and was the son of Mathurin Cassegrain and Jehanne Marquet. It is unknown what his education was but he was a priest and professor by 1654. He may have been interested in acoustics, optics and mechanics. At the time of his death he was working as a teacher giving science classes at the Collège de Chartres, a French lycée, i.e., a high-school like institution. He died at Chaudon (Eure-et-Loir) on 1 September 1693. Connection with the Cassegrain reflector The Cassegrain reflector is a reflecting telescope design that solved the problem of viewing an image without obstructing the primary mirror by using a convex secondary mirror on the optical axis to bounce the light back through a hole in the primary mirror thus permit ...
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Chartres
Chartres () is the prefecture of the Eure-et-Loir department in the Centre-Val de Loire region in France. It is located about southwest of Paris. At the 2019 census, there were 170,763 inhabitants in the metropolitan area of Chartres (as defined by the INSEE), 38,534 of whom lived in the city ( commune) of Chartres proper. Chartres is famous worldwide for its cathedral. Mostly constructed between 1193 and 1250, this Gothic cathedral is in an exceptional state of preservation. The majority of the original stained glass windows survive intact, while the architecture has seen only minor changes since the early 13th century. Part of the old town, including most of the library associated with the School of Chartres, was destroyed by Allied bombs in 1944. History Chartres was one of the principal towns in Gaul of the Carnutes, a Celtic tribe. In the Gallo-Roman period, it was called ''Autricum'', name derived from the river ''Autura'' (Eure), and afterwards ''civitas Carnutum ...
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Newtonian Telescope
The Newtonian telescope, also called the Newtonian reflector or just a Newtonian, is a type of reflecting telescope invented by the English scientist Sir Isaac Newton, using a concave primary mirror and a flat diagonal secondary mirror. Newton's first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design has made it very popular with amateur telescope makers.


Description

A Newtonian telescope is composed of a primary mirror or objective, usually parabolic in shape, and a smaller mirror called the "secondary" which is flat ...
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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 synod ...
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Cassegrain (crater)
Cassegrain is a lunar impact crater that is located on the far side of the Moon, beyond the southeastern limb. It lies to the southeast of the larger crater Lebedev, and to the northeast of the comparably-sized Priestley. It is named after the inventor of the Cassegrain reflector, who was later identified as most likely Laurent Cassegrain. The interior of this crater has a relatively dark-hued floor, a feature it has in common with other craters to the west and northwest that form part of the Mare Australe Mare Australe (Latin ''austrāle'' the "Southern Sea") is a lunar mare located in the southeastern hemisphere of the Moon. It is 997 kilometers in diameter, overlapping the near and far sides of the Moon. Smooth, dark volcanic basalt lines the .... The floor is level and mostly featureless, except for some deposits in the northwest corner. The rim is more heavily worn in the northwest corner than elsewhere, and the remaining inner wall displays a slumped shelf below the ri ...
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Nogent-le-Roi
Nogent-le-Roi () is a Communes of France, commune in the Departments of France, department of Eure-et-Loir in the Centre-Val de Loire Regions of France, region in France. It is located 27 kilometres north of Chartres and 18 kilometres south-east of Dreux. Population International relations The town is twinned with Heddesheim near Mannheim in Germany. See also *Communes of the Eure-et-Loir department References External links Official site
Communes of Eure-et-Loir Carnutes {{EureLoir-geo-stub ...
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Chaudon
Chaudon () is a commune in the Eure-et-Loir department in northern France. Population See also *Communes of the Eure-et-Loir department The following is a list of the 365 communes of the Eure-et-Loir department of France. The communes cooperate in the following intercommunalities (as of 2020):Communes of Eure-et-Loir {{EureLoir-geo-stub ...
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Chirurgeon
In modern medicine, a surgeon is a medical professional who performs surgery. Although there are different traditions in different times and places, a modern surgeon usually is also a licensed physician or received the same medical training as physicians before specializing in surgery. There are also surgeons in podiatry, dentistry, and veterinary medicine. It is estimated that surgeons perform over 300 million surgical procedures globally each year. History The first person to document a surgery was the 6th century BC Indian physician-surgeon, Sushruta. He specialized in cosmetic plastic surgery and even documented an open rhinoplasty procedure.Ira D. Papel, John Frodel, ''Facial Plastic and Reconstructive Surgery'' His magnum opus ''Suśruta-saṃhitā'' is one of the most important surviving ancient treatises on medicine and is considered a foundational text of both Ayurveda and surgery. The treatise addresses all aspects of general medicine, but the translator G. D. Si ...
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Louis XIV Of France
, house = Bourbon , father = Louis XIII , mother = Anne of Austria , birth_date = , birth_place = Château de Saint-Germain-en-Laye, Saint-Germain-en-Laye, France , death_date = , death_place = Palace of Versailles, Versailles, France , burial_date = 9 September 1715 , burial_place = Basilica of Saint-Denis , religion = Catholicism ( Gallican Rite) , signature = Louis XIV Signature.svg Louis XIV (Louis Dieudonné; 5 September 16381 September 1715), also known as Louis the Great () or the Sun King (), was King of France from 14 May 1643 until his death in 1715. His reign of 72 years and 110 days is the longest of any sovereign in history whose date is verifiable. Although Louis XIV's France was emblematic of the age of absolutism in Europe, the King surrounded himself with a variety of significant political, military, and cultural figures, such as Bossuet, Colbert, Le Brun, Le Nôtre, Lully, Mazarin, Molière, Racin ...
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Paris
Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the List of cities proper by population density, 30th most densely populated city in the world in 2020. Since the 17th century, Paris has been one of the world's major centres of finance, diplomacy, commerce, Fashion capital, fashion, gastronomy, and science. For its leading role in the arts and sciences, as well as its very early system of street lighting, in the 19th century it became known as "the City of Light". Like London, prior to the Second World War, it was also sometimes called Caput Mundi#Paris, the capital of the world. The City of Paris is the centre of the Île-de-France Regions of France, region, or Paris Region, with an estimated population of 12,262,544 in 2019, or about 19% of the population of France, making the ...
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Ferdinand Hoefer
Jean Chrétien Ferdinand Hoefer (German: ''Ferdinand Höfer'', 21 April 1811, Döschnitz – 4 May 1878) was a German-French physician and lexicographer. He is now known for his many works on the history of science. Selected works *''Éléments de chimie générale'' (1841) *''Histoire de la chimie''Volume 1Volume 2
(1842–43) *
Dictionnaire de chimie et de physique
' (1846) *''Dictionnaire de médecine pratique'' (1847) *
Afrique australe ... Afrique orientale ... Afrique centrale ... Empire de Maroc
' (Pa ...
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England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Engli ...
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Journal Des Sçavans
The ''Journal des sçavans'' (later renamed ''Journal des savans'' and then ''Journal des savants,'' lit. ''Journal of the Learned''), established by Denis de Sallo, is the earliest academic journal published in Europe. It is thought to be the earliest published scientific journal. It currently focuses on European history and premodern literature. History The first issue appeared as a twelve-page quarto pamphlet on Monday, 5 January 1665. This was shortly before the first appearance of the '' Philosophical Transactions of the Royal Society,'' on 6 March 1665. The 18th-century French physician and encyclopédiste Louis-Anne La Virotte (1725–1759) was introduced to the journal through the protection of chancellor Henri François d'Aguesseau. Its content originally included obituaries of famous men, church history, the findings of other's in a scientific manner, and legal reports. Natural philosophy was part of its original scope. It is thought to be the first published scientif ...
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