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Willebrord Snellius
Willebrord Snellius (born Willebrord Snel van Royen) (13 June 158030 October 1626) was a Dutch astronomer and mathematician, Snell. His name is usually associated with the law of refraction of light known as Snell's law. The lunar crater Snellius is named after Willebrord Snellius. The Royal Netherlands Navy has named three survey ships after Snellius, including a currently-serving vessel. Biography Willebrord Snellius was born in Leiden, Netherlands. In 1613 he succeeded his father, Rudolph Snel van Royen (1546–1613) as professor of mathematics at the University of Leiden. Snellius' triangulation In 1615, Snellius, after the work of Eratosthenes in Ptolemaic Egypt in the 3rd century BC, probably was the first to try to do a large-scale experiment to measure the circumference of the earth using triangulation. He was helped in his measurements by two of his students, the Austrian barons Erasmus and Casparus Sterrenberg. In several cities he also received su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leiden
Leiden (; in English and archaic Dutch also Leyden) is a city and municipality in the province of South Holland, Netherlands. The municipality of Leiden has a population of 119,713, but the city forms one densely connected agglomeration with its suburbs Oegstgeest, Leiderdorp, Voorschoten and Zoeterwoude with 206,647 inhabitants. The Netherlands Central Bureau of Statistics (CBS) further includes Katwijk in the agglomeration which makes the total population of the Leiden urban agglomeration 270,879, and in the larger Leiden urban area also Teylingen, Noordwijk, and Noordwijkerhout are included with in total 348,868 inhabitants. Leiden is located on the Oude Rijn, at a distance of some from The Hague to its south and some from Amsterdam to its north. The recreational area of the Kaag Lakes (Kagerplassen) lies just to the northeast of Leiden. A university city since 1575, Leiden has been one of Europe's most prominent scientific centres for more than four centuries. Leide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ibn Sahl (mathematician)
Ibn Sahl (full name: ''Abū Saʿd al-ʿAlāʾ ibn Sahl'' ; c. 940–1000) was a Persian mathematician and physicist of the Islamic Golden Age, associated with the Buyid court of Baghdad. Nothing in his name allows us to glimpse his country of origin. He is known to have written an optical treatise around 984. The text of this treatise was reconstructed by Roshdi Rashed from two manuscripts (edited 1993).: Damascus, al-Ẓāhirīya MS 4871, 3 fols., and Tehran, Millī MS 867, 11 fols. The Tehran manuscript is much longer, but it is badly damaged, and the Damascus ms. contains a section missing entirely from the Tehran ms. The Damascus ms. has the title ''Fī al-'āla al-muḥriqa'' "On the burning instruments", the Tehran ms. has a title added in a later hand ''Kitāb al-harrāqāt'' "The book of burners". Ibn Sahl is the first Muslim scholar known to have studied Ptolemy's ''Optics'', and as such an important precursor to the ''Book of Optics'' by Ibn Al-Haytham (Alhazen), wr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regenten
In the 16th, 17th and 18th centuries, the regenten (the Dutch plural for ''regent'') were the rulers of the Dutch Republic, the leaders of the Dutch cities or the heads of organisations (e.g. "regent of an orphanage"). Though not formally a hereditary "class", they were ''de facto'' "patricians", comparable to that ancient Roman class. Since the late Middle Ages Dutch cities had been run by the richer merchant families, who gradually formed a closed group. At first the lower-class citizens in the guilds and schutterijen could unite to form a certain counterbalance to the ''regenten'', but in the course of the 15th century the administration of the cities and towns became oligarchical in character. From the latter part of the 17th century the regent families were able to reserve government offices to themselves via quasi-formal contractual arrangements. In practice they could only be dislodged by political upheavals, like the Orangist revolution of 1747 and the Patriot revolt of 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangulation (surveying)
In surveying, triangulation is the process of determining the location of a point by measuring only angles to it from known points at either end of a fixed baseline by using trigonometry, rather than measuring distances to the point directly as in trilateration. The point can then be fixed as the third point of a triangle with one known side and two known angles. Triangulation can also refer to the accurate surveying of systems of very large triangles, called triangulation networks. This followed from the work of Willebrord Snell in 1615–17, who showed how a point could be located from the angles subtended from ''three'' known points, but measured at the new unknown point rather than the previously fixed points, a problem called resectioning. Surveying error is minimized if a mesh of triangles at the largest appropriate scale is established first. Points inside the triangles can all then be accurately located with reference to it. Such triangulation methods were used for accur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Radius
Earth radius (denoted as ''R''🜨 or R_E) is the distance from the center of Earth to a point on or near its surface. Approximating the figure of Earth by an Earth spheroid, the radius ranges from a maximum of nearly (equatorial radius, denoted ''a'') to a minimum of nearly (polar radius, denoted ''b''). A ''nominal Earth radius'' is sometimes used as a unit of measurement in astronomy and geophysics, which is recommended by the International Astronomical Union to be the equatorial value. A globally-average value is usually considered to be with a 0.3% variability (±10 km) for the following reasons. The International Union of Geodesy and Geophysics (IUGG) provides three reference values: the ''mean radius'' (R) of three radii measured at two equator points and a pole; the ''authalic radius'', which is the radius of a sphere with the same surface area (R); and the ''volumetric radius'', which is the radius of a sphere having the same volume as the ellipsoid (R). All three ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eratosthenes
Eratosthenes of Cyrene (; grc-gre, Ἐρατοσθένης ; – ) was a Greek polymath: a mathematician, geographer, poet, astronomer, and music theorist. He was a man of learning, becoming the chief librarian at the Library of Alexandria. His work is comparable to what is now known as the study of geography, and he introduced some of the terminology still used today. He is best known for being the first person known to calculate the circumference of the Earth, which he did by using the extensive survey results he could access in his role at the Library; his calculation was remarkably accurate. He was also the first to calculate Earth's axial tilt, which has also proved to have remarkable accuracy. He created the first global projection of the world, incorporating parallels and meridians based on the available geographic knowledge of his era. Eratosthenes was the founder of scientific chronology; he used Egyptian and Persian records to estimate the dates of the main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Museum Boerhaave - Snellius Quadrant
A museum ( ; plural museums or, rarely, musea) is a building or institution that cares for and displays a collection of artifacts and other objects of artistic, cultural, historical, or scientific importance. Many public museums make these items available for public viewing through exhibits that may be permanent or temporary. The largest museums are located in major cities throughout the world, while thousands of local museums exist in smaller cities, towns, and rural areas. Museums have varying aims, ranging from the conservation and documentation of their collection, serving researchers and specialists, to catering to the general public. The goal of serving researchers is not only scientific, but intended to serve the general public. There are many types of museums, including art museums, natural history museums, science museums, war museums, and children's museums. According to the International Council of Museums (ICOM), there are more than 55,000 museums in 202 countries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Netherlands
) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherlands , established_title2 = Act of Abjuration , established_date2 = 26 July 1581 , established_title3 = Peace of Münster , established_date3 = 30 January 1648 , established_title4 = Kingdom established , established_date4 = 16 March 1815 , established_title5 = Liberation Day (Netherlands), Liberation Day , established_date5 = 5 May 1945 , established_title6 = Charter for the Kingdom of the Netherlands, Kingdom Charter , established_date6 = 15 December 1954 , established_title7 = Dissolution of the Netherlands Antilles, Caribbean reorganisation , established_date7 = 10 October 2010 , official_languages = Dutch language, Dutch , languages_type = Regional languages , languages_sub = yes , languages = , languages2_type = Reco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HNLMS Snellius
HNLMS ''Snellius'' (A802) is a hydrographic survey vessel of the Royal Netherlands Navy. The ''Snellius'' has a sister ship, . ''Snellius'' is named after the mathematician Willebrord Snellius who contributed significantly to hydrography. Construction and service The ship was completed in the Netherlands from a Romanian-built hull. The ships have different tasks: surveying the sea, operating as guard ship, representing the Netherlands at home and abroad, assisting maritime scientific surveys by the Ministry of Defence {{unsourced, date=February 2021 A ministry of defence or defense (see spelling differences), also known as a department of defence or defense, is an often-used name for the part of a government responsible for matters of defence, found in states ... and assisting rescue operations. The current ''Snellius'' is the third hydrographic vessel with this name. References {{DEFAULTSORT:Snellius Snellius-class hydrographic survey vessels Survey ships Auxiliary shi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snellius (crater)
Snellius is a lunar impact crater located near the southeast limb of the Moon. The rim of Snellius is heavily worn and eroded, with overlapping craterlets. The floor is somewhat irregular and uneven. The western rim marks the start of the Vallis Snellius, one of the longest valleys on the Moon. It continues nearly 500 kilometers to the northwest to near the edge of Mare Nectaris. Its origin is most likely associated with the formation of the lunar mare. To the northeast is the large crater Petavius. South of Snellius is the crater Stevinus. Just to the northwest is Snellius A, a crater with a notable ray system that overlaps the southwest reaches of Mare Fecunditatis to the north. It is named after Dutch astronomer, mathematician and physicist, Willebrord Snellius Willebrord Snellius (born Willebrord Snel van Royen) (13 June 158030 October 1626) was a Dutch astronomer and mathematician, Snell. His name is usually associated with the law of refraction of light known as S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Crater
Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated. History The word ''crater'' was adopted from the Greek word for "vessel" (, a Greek vessel used to mix wine and water). Galileo built his first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions. These were named craters by Johann Hieronymus Schröter (1791), extending its previous use with volcanoes. Robert Hooke in ''Micrographia'' (1665) proposed two hypotheses for lunar crater formation: one, that the craters were caused by projectile bombardment from space, the other, that they were the products of subterranean lunar volcanism. Scientific opinion as to the origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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