1.
Universiteit Leiden
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Leiden University, located in the city of Leiden, is the oldest university in the Netherlands. The university was founded in 1575 by William, Prince of Orange, the Dutch Royal Family and Leiden University still have a close relationship, Queens Juliana and Beatrix and King Willem-Alexander are all former students. Leiden University has seven faculties, over 50 departments and enjoys an international reputation. Shanghai Jiao Tong Universitys 2011 Academic Ranking of World Universities ranked Leiden University as the 29th best university worldwide, the Times Higher Education World University Rankings consistently rank Leiden University as the best university in Continental Europe for Arts and Humanities. During this time Leiden was home to figures as René Descartes, Rembrandt, Christiaan Huygens, Hugo Grotius, Baruch Spinoza. The university is a member of the Coimbra Group, the Europaeum, Leiden University houses more than 40 national and international research institutes. In 1575, the emerging Dutch Republic did not have any universities in its northern heartland, the only other university in the Habsburg Netherlands was the University of Leuven in southern Leuven, firmly under Spanish control. It is said the choice fell on Leiden as a reward for the defence of Leiden against Spanish attacks in the previous year. Ironically, the name of Philip II of Spain, Williams adversary, appears on the foundation certificate. Philip II replied by forbidding any subject to study in Leiden, renowned philosopher Baruch Spinoza was based close to Leiden during this period and interacted with numerous scholars at the university. At the end of the century, Leiden University again became one of Europes leading universities. At the world’s first university low-temperature laboratory, professor Heike Kamerlingh Onnes achieved temperatures of one degree above absolute zero of −273 degrees Celsius. In 1908 he was also the first to succeed in liquifying helium, Kamerlingh Onnes was awarded the Nobel Prize for Physics in 1913. In 2005 the manuscript of Einstein on the theory of the monatomic ideal gas was discovered in one of Leidens libraries. Of the seventy-seven Spinozapremie, nineteen were granted to professors of the Universiteit Leiden, literary historian Frits van Oostrom was the first professor of Leiden to be granted the Spinoza award for his work on developing the NLCM centre into a top research centre. Among other leading professors are Wim Blockmans, professor of Medieval History, the portraits of many famous professors since the earliest days hang in the university aula, one of the most memorable places, as Niebuhr called it, in the history of science. The University Library, which has more than 5 and it houses the largest collections worldwide on Indonesia and the Caribbean. Scholars from all over the world visit Leiden University Library, the oldest in the Netherlands, the anatomical and pathological laboratories of the university are modern, and the museums of geology and mineralogy have been restored
2.
Kwadrant (meetinstrument)
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A quadrant is an instrument that is used to measure angles up to 90°. It was originally proposed by Ptolemy as a kind of astrolabe. Several different variations of the instrument were produced by medieval Muslim astronomers. There are several types of quadrants, Mural quadrants used for measuring the altitudes of astronomical objects, large frame-based instruments used for measuring angular distances between astronomical objects. Geometric quadrant used by surveyors and navigators, davis quadrant a compact, framed instrument used by navigators for measuring the altitude of an astronomical object. They can also be classified as Altitude - The plain quadrant with plumb line, gunters - A quadrant used for time determination. Invented by Edmund Gunter in 1623, islamic - King identified four types of quadrants that were produced by Muslim astronomers. The sine quadrant - also known as the Sinecal Quadrant – was used for solving trigonometric problems and it was developed by al-Khwarizmi in 9th century Baghdad and prevalent until the nineteenth century. Its defining feature is a graph-paper like grid on one side that is divided into sixty equal intervals on each axis and is bounded by a 90 degree graduated arc. A cord was attached to the apex of the quadrant with a bead, for calculation, and they were also sometimes drawn on the back of astrolabes. The universal quadrant – used for solving problems for any latitude. Some astrolabes are also printed on the back with the universal quadrant like an astrolabe created by Ibn al-Sarrāj, the horary quadrant – used for finding the time with the sun, The horary quadrant could be used to find the time either in equal or unequal hours. Different sets of markings were created for either equal or unequal hours, for measuring the time in equal hours, the horary quadrant could only be used for one specific latitude while a quadrant for unequal hours could be used anywhere based on an approximate formula. One edge of the quadrant had to be aligned with the sun, and once aligned, an example exists dated 1396, from European sources. The oldest horary quadrant was found during an excavation in 2013 in the Hanseatic town of Zutphen and is dated ca.1300 and is in the local Stedelijk Museum in Zutphen. ). The astrolabe/almucantar quadrant – a quadrant developed from the astrolabe, This quadrant was marked with one half of a typical astrolabe plate as astrolabe plates are symmetrical. A cord attached from the centre of the quadrant with a bead at the end was moved to represent the position of a celestial body. The ecliptic and star positions were marked on the quadrant for the above and these quadrants proved to be very popular alternatives to astrolabes
3.
Willebrord Snel van Royen
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Willebrord Snellius was a Dutch astronomer and mathematician, known in the English-speaking world as Snell. The same law was also investigated by Ptolemy and in the Middle Ages by Witelo, the lunar crater Snellius is named after Willebrord Snellius. The Royal Netherlands Navy has named three ships after Snellius, including a currently-serving vessel. Willebrord Snellius was born in Leiden, Netherlands, in 1613 he succeeded his father, Rudolph Snel van Royen as professor of mathematics at the University of Leiden. He was helped in his measurements by two of his students, the Austrian barons Erasmus and Casparus Sterrenberg, in several cities he also received support of friends among the city leaders. In his work The terrae Ambitus vera quantitate under the authors name Snellius describes the methods he used and he came up with an estimate of 28,500 Rhineland rods - in modern units 107.37 km for one degree of latitude. 360 times 107.37 then gives a circumference of the Earth of 38,653 km, the actual circumference is 40,075 kilometers, so Snellius underestimated the circumference of the earth by 3. 5%. Snellius came to his result by calculating the distances between a number of points in the plain west and southwest of the Netherlands using triangulation. In order to carry out these measurements accurately Snellius had a large quadrant built and this quadrant can still be seen in the Museum Boerhaave in Leiden. In a network of fourteen cities a total of 53 triangulation measurements were made, in his calculations Snellius made use of a solution for what is now called the Snellius–Pothenot problem. By necessity Snellius his high points were nearly all church spires, there were hardly any other tall buildings in Snellius time in the west of the Netherlands. More or less ordered from north to south and/or in successive order of measuring Snellius used a network of fourteen points, Alkmaar. The difference in latitude between Alkmaar and Breda is 1.0436 degree, assuming Snellius corrected for this he must have calculated a distance of 107.37 *1.0436 =112.05 kilometers between the Sint-Laurenskerk in Alkmaar and the Grote Kerk in Breda. Snellius was also a mathematician, producing a new method for calculating π—the first such improvement since ancient times. He rediscovered the law of refraction in 1621, in addition to the Eratosthenes Batavus, he published Cyclometricus, de circuli dimensione, and Tiphys Batavus. He also edited Coeli et siderum in eo errantium observationes Hassiacae, a work on trigonometry authored by Snellius was published a year after his death. Snellius died at Leiden on October 1626, at the age of 46 from an illness diagnosed as colic, oConnor, John J. Robertson, Edmund F. Willebrord van Royen Snell, MacTutor History of Mathematics archive, University of St Andrews. This article incorporates text from a now in the public domain, Chisholm, Hugh, ed. Snell
4.
Frederik Kaiser
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Frederik Kaiser was a Dutch astronomer. He was director of the Leiden Observatory from 1838 until his death and he made a series of drawings of Mars at its opposition in 1862 and made a fairly precise determination of its rotational period. Craters on Mars and on the Moon are named in his honour, in Richard Proctors now-abandoned Martian nomenclature, Syrtis Major Planum was called the Kaiser Sea. This nomenclature was dropped in favor of the one introduced by Giovanni Schiaparelli. Kaisers parents were Johann Wilhelm Keyser and Anna Sibella Liernur but he was raised by his uncle Johan Frederik Keyser from the age of eight, obituary Petra van der Heijden Frederik Kaiser and the modernisation of Dutch astronomy
5.
Hortus botanicus Leiden
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The Hortus botanicus of Leiden is the oldest botanical garden of the Netherlands, and one of the oldest in the world. It is located in the part of the historical centre of the city. In 1587 the young University of Leiden asked for permission from the mayor of Leiden to establish a hortus academicus behind the university building, the request was granted in 1590, and the famous botanist Carolus Clusius was appointed as prefect. Clusius arrived in Leiden in 1593 and his knowledge, reputation, and international contacts allowed him to set up a very extensive plant collection. Clusius also urged the Dutch East India Company to collect plants, the original garden set up by Clusius was small, but contained more than 1000 different plants. The collecting of tropical and sub-tropical plants was continued under Clusius successors, another major contribution to the collections was made by Philipp Franz von Siebold, a German physician who was employed on Deshima by the VOC from 1823 until his expulsion by Japan in 1829. During that period he collected many dried and living plants from all over Japan, the first greenhouses appeared in the Hortus in the second half of the 17th century, the monumental Orangery was built between 1740 and 1744. From its original plan the Hortus was expanded in 1736 by Adriaan van Royen and Carl Linnaeus, in 1857, a part was used for building the new Leiden Observatory. From a historical perspective, the old Golden Chain, planted in 1601, the Tuliptree from 1682, the greenhouses with Victoria amazonica and other tropical plants, and the large collection of sub-tropical plants in the recently renovated Orangery and the new Winter Garden draw many visitors. The park itself is an oasis inside the old city, with more interesting plants. A Japanese garden in honour of Von Siebold opened in 1990, a reconstruction of Clusius original garden, based on a plant list dating from the end of the 16th century, was opened in 2009. From a scientific point of view, the Leiden Hortus is known for its collections of Asian Araceae, Hoya, Dischidia, Nepenthes, Ferns, karstens, WKH and Kleibrink, H De Leidse Hortus, een botanische erfenis. ISBN 90-70072-92-0 Schwartz, L Flora in Leiden, de verborgen tuinen van de stad, ISBN 90-6179-126-X Hortus botanicus Leiden web site Nationaal Herbarium Nederland web site
6.
Jacobus Golius
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Jacob Golius born Jacob van Gool was an Orientalist and mathematician based at the University of Leiden in Netherlands. He is primarily remembered as an Orientalist and he published Arabic texts in Arabic at Leiden, and did Arabic-to-Latin translations. His best-known work is an Arabic-to-Latin dictionary, Lexicon Arabico-Latinum, which he sourced for the most part from the Sihah dictionary of Al-Jauhari, Golius was born in The Hague. He went to the University of Leiden in 1612 to study mathematics, in 1618 he registered again to study Arabic and other Eastern languages at Leiden, where he was the most distinguished pupil of Erpenius. In 1622 he accompanied the Dutch embassy to Morocco, and on his return he was chosen to succeed Erpenius as professor of Arabic at Leiden, in the following year he set out on a tour of the Eastern Mediterranean lands, from which he did not return until 1629. A key purpose of the tour was to collect Arabic texts, the remainder of his life was spent at Leiden where he held the chair of mathematics as well as that of Arabic. Golius taught mathematics to the French philosopher René Descartes, and later corresponded with him and it is therefore highly probable that he was able to read to him parts of the mathematical Arabic texts he had started to collect, among others on the Conics. Among his earlier publications may be mentioned editions of various Arabic texts, in 1656 he published a new edition, with considerable additions, of the Grammatica Arabica of Erpenius. After his death, there was found among his papers a Dictionarium Persico-Latinum which was published, with additions, Golius also edited, translated and annotated the astronomical treatise of the 9th century Arabic astronomer Al-Farghani. Golius possessed mainstream medieval Arabic dictionaries written solely in Arabic, and was able to translate their contents into Latin, raphelengius did not have the benefit of seeing these Arabic dictionaries. Goliuss dictionary was later improved and expanded by Georg Freytags Arabic-to-Latin dictionary in 1837
7.
Wiskunde
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Mathematics is the study of topics such as quantity, structure, space, and change. There is a range of views among mathematicians and philosophers as to the exact scope, Mathematicians seek out patterns and use them to formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proof, when mathematical structures are good models of real phenomena, then mathematical reasoning can provide insight or predictions about nature. Through the use of abstraction and logic, mathematics developed from counting, calculation, measurement, practical mathematics has been a human activity from as far back as written records exist. The research required to solve mathematical problems can take years or even centuries of sustained inquiry, rigorous arguments first appeared in Greek mathematics, most notably in Euclids Elements. Galileo Galilei said, The universe cannot be read until we have learned the language and it is written in mathematical language, and the letters are triangles, circles and other geometrical figures, without which means it is humanly impossible to comprehend a single word. Without these, one is wandering about in a dark labyrinth, carl Friedrich Gauss referred to mathematics as the Queen of the Sciences. Benjamin Peirce called mathematics the science that draws necessary conclusions, David Hilbert said of mathematics, We are not speaking here of arbitrariness in any sense. Mathematics is not like a game whose tasks are determined by arbitrarily stipulated rules, rather, it is a conceptual system possessing internal necessity that can only be so and by no means otherwise. Albert Einstein stated that as far as the laws of mathematics refer to reality, they are not certain, Mathematics is essential in many fields, including natural science, engineering, medicine, finance and the social sciences. Applied mathematics has led to entirely new mathematical disciplines, such as statistics, Mathematicians also engage in pure mathematics, or mathematics for its own sake, without having any application in mind. There is no clear line separating pure and applied mathematics, the history of mathematics can be seen as an ever-increasing series of abstractions. The earliest uses of mathematics were in trading, land measurement, painting and weaving patterns, in Babylonian mathematics elementary arithmetic first appears in the archaeological record. Numeracy pre-dated writing and numeral systems have many and diverse. Between 600 and 300 BC the Ancient Greeks began a study of mathematics in its own right with Greek mathematics. Mathematics has since been extended, and there has been a fruitful interaction between mathematics and science, to the benefit of both. Mathematical discoveries continue to be made today, the overwhelming majority of works in this ocean contain new mathematical theorems and their proofs. The word máthēma is derived from μανθάνω, while the modern Greek equivalent is μαθαίνω, in Greece, the word for mathematics came to have the narrower and more technical meaning mathematical study even in Classical times
8.
Messing (legering)
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Brass is a metal alloy made of copper and zinc, the proportions of zinc and copper can be varied to create a range of brasses with varying properties. It is an alloy, atoms of the two constituents may replace each other within the same crystal structure. By comparison, bronze is principally an alloy of copper and tin, however, bronze and brass may also include small proportions of a range of other elements including arsenic, phosphorus, aluminium, manganese, and silicon. The term is applied to a variety of brasses. Modern practice in museums and archaeology increasingly avoids both terms for objects in favour of the all-embracing copper alloy. It is also used in zippers, Brass is often used in situations in which it is important that sparks not be struck, such as in fittings and tools used near flammable or explosive materials. Brass has higher malleability than bronze or zinc, the relatively low melting point of brass and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard, the density of brass is 8.4 to 8.73 grams per cubic centimetre. Today, almost 90% of all alloys are recycled. Because brass is not ferromagnetic, it can be separated from ferrous scrap by passing the scrap near a powerful magnet, Brass scrap is collected and transported to the foundry where it is melted and recast into billets. Billets are heated and extruded into the form and size. The general softness of brass means that it can often be machined without the use of cutting fluid, aluminium makes brass stronger and more corrosion-resistant. Aluminium also causes a highly beneficial hard layer of oxide to be formed on the surface that is thin, transparent. Tin has an effect and finds its use especially in seawater applications. Combinations of iron, aluminium, silicon and manganese make brass wear and tear resistant, to enhance the machinability of brass, lead is often added in concentrations of around 2%. Since lead has a melting point than the other constituents of the brass. The pattern the globules form on the surface of the brass increases the available surface area which in turn affects the degree of leaching. In addition, cutting operations can smear the lead globules over the surface and these effects can lead to significant lead leaching from brasses of comparatively low lead content
9.
Kassel (Duitsland)
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Kassel is a city located on the Fulda River in northern Hesse, Germany. It is the seat of the Regierungsbezirk Kassel and the Kreis of the same name and has 200,507 inhabitants in December 2015. The former capital of the state of Hesse-Kassel has many palaces and parks, including the Bergpark Wilhelmshöhe, Kassel is also known for the documenta exhibitions of contemporary art. The citys name is derived from the ancient Castellum Cattorum, a castle of the Chatti, Kassel was first mentioned in 913 AD, as the place where two deeds were signed by King Conrad I. The place was called Chasella and was a fortification at a crossing the Fulda river. A deed from 1189 certifies that Cassel had city rights, in 1567, the Landgraviate of Hesse, until then centered in Marburg, was divided among four sons, with Hesse-Kassel becoming one of its successor states. Kassel was its capital and became a centre of Calvinist Protestantism in Germany, strong fortifications were built to protect the Protestant stronghold against Catholic enemies. Secret societies, such as Rosicrucianism flourished, with Christian Rosenkreutz’s work Fama Fraternitis first published in 1617, in 1685, Kassel became a refuge for 1,700 Huguenots who found shelter in the newly established borough of Oberneustadt. Landgrave Charles, who was responsible for this act, also ordered the construction of the Oktagon. In the early 19th century, the Brothers Grimm lived in Kassel and they collected and wrote most of their fairy tales there. At that time, around 1803, the Landgraviate was elevated to a Principality, shortly after, it was annexed by Napoleon and in 1807 it became the capital of the short-lived Kingdom of Westphalia under Napoleons brother Jérôme. The Electorate was restored in 1813, having sided with Austria in the Austro-Prussian War to gain supremacy in Germany, the principality was annexed by Prussia in 1866. The Prussian administration united Nassau, Frankfurt and Hesse-Kassel into the new Prussian province of Hesse-Nassau, Kassel ceased to be a princely residence, but soon developed into a major industrial centre, as well as a major railway junction. Henschel & Son, the largest railway locomotive manufacturer in Germany at the end of the century, was based in Kassel. In 1870, after the Battle of Sedan, Napoleon III was sent as a prisoner to the castle of Wilhelmshohe above the city, during World War I the German military headquarters were located in the castle of Wilhelmshohe. In the late 1930s Nazis destroyed Heinrich Hübschs Kassel Synagogue, the most severe bombing of Kassel in World War II destroyed 90% of the downtown area, some 10,000 people were killed, and 150,000 were made homeless. Most of the casualties were civilians or wounded soldiers recuperating in local hospitals, Karl Gerland replaced the regional Gauleiter, Karl Weinrich, soon after the raid. The Allied ground advance into Germany reached Kassel at the beginning of April 1945, post-war, most of the ancient buildings were not restored, and large parts of the city area were completely rebuilt in the style of the 1950s
10.
Komeet Halley
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Halleys Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 75–76 years. Halley is the only known short-period comet that is visible to the naked eye from Earth. Halley last appeared in the parts of the Solar System in 1986. Halleys returns to the inner Solar System have been observed and recorded by astronomers since at least 240 BC, clear records of the comets appearances were made by Chinese, Babylonian, and medieval European chroniclers, but were not recognized as reappearances of the same object at the time. The comets periodicity was first determined in 1705 by English astronomer Edmond Halley, Comet Halley is commonly pronounced /ˈhæli/, rhyming with valley, or /ˈheɪli/, rhyming with daily. Spellings of Edmond Halleys name during his lifetime included Hailey, Haley, Hayley, Halley, Hawley, Halley was the first comet to be recognized as periodic. Until the Renaissance, the consensus on the nature of comets. This idea was disproved in 1577 by Tycho Brahe, who used parallax measurements to show that comets must lie beyond the Moon, many were still unconvinced that comets orbited the Sun, and assumed instead that they must follow straight paths through the Solar System. In 1687, Sir Isaac Newton published his Philosophiæ Naturalis Principia Mathematica, in which he outlined his laws of gravity and his work on comets was decidedly incomplete. Halley thus concluded that all three comets were, in fact, the same object returning every 76 years, a period that has since been amended to every 75–76 years. After a rough estimate of the perturbations the comet would sustain from the attraction of the planets. Halley died in 1742 before he could observe this himself, Halleys prediction of the comets return proved to be correct, although it was not seen until 25 December 1758, by Johann Georg Palitzsch, a German farmer and amateur astronomer. It did not pass through its perihelion until 13 March 1759 and this effect was computed prior to its return by a team of three French mathematicians, Alexis Clairaut, Joseph Lalande, and Nicole-Reine Lepaute. The confirmation of the return was the first time anything other than planets had been shown to orbit the Sun. It was also one of the earliest successful tests of Newtonian physics, the comet was first named in Halleys honour by French astronomer Nicolas Louis de Lacaille in 1759. Some scholars have proposed that first-century Mesopotamian astronomers already had recognized Halleys Comet as periodic and this theory notes a passage in the Bavli Talmud that refers to a star which appears once in seventy years that makes the captains of the ships err. It was necessary to use ancient Chinese comet observations to constrain their calculations, Halleys orbital period over the last 3 centuries has been between 75–76 years, although it has varied between 74–79 years since 240 BC. Its orbit around the Sun is highly elliptical, with an eccentricity of 0.967