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Al-Urdi
Al-Urdi (full name: Moayad Al-Din Al-Urdi Al-Amiri Al-Dimashqi) () (d. 1266) was a medieval Syrian Arab astronomer and geometer. Born circa 1200, presumably (from the nisba ''al‐ʿUrḍī'') in the village of ''ʿUrḍ'' in the Syrian desert between Palmyra and Resafa, he moved to Damascus at some point before 1239, where he worked as an engineer and teacher of geometry, and built instruments for al-Malik al-Mansur of Hims. In 1259 he moved to Maragha in northwestern Iran, after being asked by Nasir al-Din al-Tusi to help establish the Maragha observatory under the patronage of Hulagu.PDF version Al-Urdi's most notable works are ''Risālat al-Raṣd'', a treatise on observational instruments, and ''Kitāb al-Hayʾa'' (كتاب الهيئة), a work on theoretical astronomy. His influence can be seen on Bar Hebraeus and Qutb al-Din al-Shirazi, in addition to being quoted by Ibn al-Shatir. Al-Urdi contributed to the construction of the observatory outside of the city, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ibn Al-Shatir
ʿAbu al-Ḥasan Alāʾ al‐Dīn bin Alī bin Ibrāhīm bin Muhammad bin al-Matam al-Ansari, known as Ibn al-Shatir or Ibn ash-Shatir (; 1304–1375) was an Arab astronomer, mathematician and engineer. He worked as '' muwaqqit'' (موقت, timekeeper) in the Umayyad Mosque in Damascus and constructed a sundial for its minaret in 1371/72. Biography Ibn al-Shatir was born in Damascus, Mamluk Sultanate around the year 1304. His father died when he was six years old. His grandfather took him in which resulted in Ibn al-Shatir learning the craft of inlaying ivory. Ibn al-Shatir traveled to Cairo and Alexandria to study astronomy, where he fell in, inspired him. After completing his studies with Abu 'Ali al-Marrakushi, Ibn al-Shatir returned to his home in Damascus where he was then appointed ''muwaqqit'' (timekeeper) of the Umayyad Mosque. Part of his duties as ''muwaqqit'' involved keeping track of the times of the five daily prayers and when the month of Ramadan would begin and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicycle
In the Hipparchian, Ptolemaic, and Copernican systems of astronomy, the epicycle (, meaning "circle moving on another circle") was a geometric model used to explain the variations in speed and direction of the apparent motion of the Moon, Sun, and planets. In particular it explained the apparent retrograde motion of the five planets known at the time. Secondarily, it also explained changes in the apparent distances of the planets from the Earth. It was first proposed by Apollonius of Perga at the end of the 3rd century BC. It was developed by Apollonius of Perga and Hipparchus of Rhodes, who used it extensively, during the 2nd century BC, then formalized and extensively used by Ptolemy in his 2nd century AD astronomical treatise the '' Almagest''. Epicyclical motion is used in the Antikythera mechanism, itation requested/sup> an ancient Greek astronomical device, for compensating for the elliptical orbit of the Moon, moving faster at perigee and slower at apogee than ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equant
Equant (or punctum aequans) is a mathematical concept developed by Claudius Ptolemy in the 2nd century AD to account for the observed motion of the planets. The equant is used to explain the observed speed change in different stages of the planetary orbit. This planetary concept allowed Ptolemy to keep the theory of uniform circular motion alive by stating that the path of heavenly bodies was uniform around one point and circular around another point. Ptolemy does not have a word for the equant – he used expressions such as "the eccentre producing the mean motion". Placement The equant point (shown in the diagram by the large • ), is placed so that it is directly opposite to Earth from the deferent's center, known as the ''eccentric'' (represented by the × ). A planet or the center of an epicycle (a smaller circle carrying the planet) was conceived to move at a constant angular speed with respect to the equant. To a hypothetical observer placed at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollonius' Theorem
In geometry, Apollonius's theorem is a theorem relating the length of a median of a triangle to the lengths of its sides. It states that the sum of the squares of any two sides of any triangle equals twice the square on half the third side, together with twice the square on the median bisecting the third side. The theorem is found as proposition VII.122 of Pappus of Alexandria's ''Collection'' (). It may have been in Apollonius of Perga's lost treatise ''Plane Loci'' (c. 200 BC), and was included in Robert Simson's 1749 reconstruction of that work. Statement and relation to other theorem In any triangle ABC, if AD is a median (, BD, = , CD, ), then , AB, ^2+, AC, ^2=2(, BD, ^2+, AD, ^2). It is a special case of Stewart's theorem. For an isosceles triangle with , AB, = , AC, , the median AD is perpendicular to BC and the theorem reduces to the Pythagorean theorem for triangle ADB (or triangle ADC). From the fact that the diagonals of a parallelogram bisect each other, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copernicus
Nicolaus Copernicus (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a mathematical model, model of Celestial spheres#Renaissance, the universe that placed heliocentrism, the Sun rather than Earth at its center. Copernicus likely developed his model independently of Aristarchus of Samos, an List of ancient Greek astronomers, ancient Greek astronomer who had formulated such a model some eighteen centuries earlier. The publication of Copernicus' model in his book ' (''On the Revolutions of the Celestial Spheres''), just before his death in 1543, was a major event in the history of science, triggering the Copernican Revolution and making a pioneering contribution to the Scientific Revolution. Copernicus was born and died in Royal Prussia, a semiautonomous and multilingual region created within the Crown of the Kingdom of Poland from lands regained from the Teutonic Order after the Thirteen Years' War (1454–1466), Thirteen Years' War. A Poly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto E
Otto is a masculine German given name and a surname. It originates as an Old High German short form (variants '' Audo'', '' Odo'', '' Udo'') of Germanic names beginning in ''aud-'', an element meaning "wealth, prosperity". The name is recorded from the 7th century ( Odo, son of Uro, courtier of Sigebert III). It was the name of three 10th-century German kings, the first of whom was Otto I the Great, the first Holy Roman Emperor, founder of the Ottonian dynasty. The Gothic form of the prefix was ''auda-'' (as in e.g. '' Audaþius''), the Anglo-Saxon form was ''ead-'' (as in e.g. '' Eadmund''), and the Old Norse form was '' auð-''. Due to Otto von Bismarck, the given name ''Otto'' was strongly associated with the German Empire in the later 19th century. It was comparatively frequently given in the United States (presumably in German American families) during the 1880s to 1890s, remaining in the top 100 most popular masculine given names in the US throughout 1880–1898, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Narcissus Marsh
Narcissus Marsh (20 December 1638 – 2 November 1713) was an English clergyman who was successively Church of Ireland Bishop of Ferns and Leighlin, Archbishop of Cashel, Archbishop of Dublin and Archbishop of Armagh. He also served as the 13th Provost of Trinity College Dublin from 1679 to 1683. Marsh was born at Hannington, Wiltshire and educated at Magdalen Hall, Oxford. In 1658, he became a fellow of Exeter College, Oxford. In 1662, he was ordained and presented to the living of Swindon, which he resigned from in the following year. After acting as chaplain to Seth Ward, Bishop of Exeter and then Bishop of Salisbury, and Lord Chancellor Clarendon, he was elected principal of St Alban Hall, Oxford, in 1673. In 1679, he was appointed Provost of Trinity College Dublin, where he did much to encourage the study of the Irish language. He helped to found the Dublin Philosophical Society and contributed to it a paper entitled ''Introductory Essay to the Doctrine of Sounds' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bodleian Library
The Bodleian Library () is the main research library of the University of Oxford. Founded in 1602 by Sir Thomas Bodley, it is one of the oldest libraries in Europe. With over 13 million printed items, it is the second-largest library in Britain after the British Library. Under the Legal Deposit Libraries Act 2003, it is one of six legal deposit libraries for works published in the United Kingdom, and under Irish law it is entitled to request a copy of each book published in the Republic of Ireland. Known to Oxford scholars as "Bodley" or "the Bod", it operates principally as a reference library and, in general, documents may not be removed from the reading rooms. In 2000, a number of libraries within the University of Oxford were brought together for administrative purposes under the aegis of what was initially known as Oxford University Library Services (OULS), and since 2010 as the Bodleian Libraries, of which the Bodleian Library is the largest component. All coll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Almagest
The ''Almagest'' ( ) is a 2nd-century Greek mathematics, mathematical and Greek astronomy, astronomical treatise on the apparent motions of the stars and planetary paths, written by Ptolemy, Claudius Ptolemy ( ) in Koine Greek. One of the most influential scientific texts in history, it canonized a geocentric model of the Universe that was accepted for more than 1,200 years from its origin in Hellenistic Roman-era Alexandria, Alexandria, in the medieval Byzantine and Islamic Golden Age, Islamic worlds, and in Western Europe through the Middle Ages and early Renaissance until Copernicus. It is also a key source of information about ancient Greek astronomy. Ptolemy set up a public inscription at Canopus, Egypt, in 147 or 148. Norman T. Hamilton found that the version of Ptolemy's models set out in the ''Canopic Inscription'' was earlier than the version in the ''Almagest''. Hence the ''Almagest'' could not have been completed before about 150, a quarter-century after Ptolemy began ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptolemy
Claudius Ptolemy (; , ; ; – 160s/170s AD) was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine science, Byzantine, Islamic science, Islamic, and Science in the Renaissance, Western European science. The first was his astronomical treatise now known as the ''Almagest'', originally entitled ' (, ', ). The second is the ''Geography (Ptolemy), Geography'', which is a thorough discussion on maps and the geographic knowledge of the Greco-Roman world. The third is the astrological treatise in which he attempted to adapt horoscopic astrology to the Aristotelian physics, Aristotelian natural philosophy of his day. This is sometimes known as the ' (, 'On the Effects') but more commonly known as the ' (from the Koine Greek meaning 'four books'; ). The Catholic Church promoted his work, which included the only mathematically sound geocentric model of the Sola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematisch-Physikalischer Salon
The Mathematisch-Physikalischer Salon (, ''Royal Cabinet of Mathematical and Physical Instruments'') in Dresden, Germany, is a museum of historic clocks and scientific instruments. Its holdings include terrestrial and celestial globes, astronomical, optical and geodetic devices dating back to the 16th century, as well as historic instruments for calculating and drawing length, mass, temperature and air pressure. Fritz Löffler: ''Das alte Dresden – Geschichte seiner Bauten''. 16th ed. Leipzig: Seemann, 2006, The Mathematisch-Physikalischer Salon is part of the Staatliche Kunstsammlungen Dresden (State Art Collections). It is located in the Zwinger (Dresden), Zwinger. Today's presentation After a general reconstruction of the Zwinger, the museum has been reopened April 14, 2013. The new exhibition presents about 500 historical scientific instruments. They are shown in four chapters. * ''The Cosmos of the Prince'': Mechanical marvels and mathematical instruments fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
