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Sine Quadrant
250px, Sinecal Quadrant or as it is known in Arabic: Rub‘ul mujayyab The sine quadrant (Arabic: , ), sometimes known as the "sinecal quadrant", was a type of quadrant used by medieval Arabic astronomers. The instrument could be used to measure celestial angles, to tell time, to find directions, to perform trigonometric computations, or to determine the apparent positions of any celestial object for any time. The name is derived from the Arabic meaning 'a quarter' and meaning 'marked with sine'. It was described by Muhammad ibn Mūsā al-Khwārizmī in 9th-century Baghdad, and was used throughout the medieval Islamic period to determine the proper times for Islamic prayer.David A. King, "Islamic Astronomy", in Christopher Walker (1999), ed., Astronomy before the telescope, p. 167-168. British Museum Press. . Description The instrument is a quarter of a circle made of wood or metal (usually brass) divided on its arc side into 90 equal parts or degrees. The 90 divisions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sine Quadrant-Iznik Museum-Turkey
In mathematics, sine and cosine are trigonometric functions of an angle. The sine and cosine of an acute angle are defined in the context of a right triangle: for the specified angle, its sine is the ratio of the length of the side that is opposite that angle to the length of the longest side of the triangle (the hypotenuse), and the cosine is the ratio of the length of the adjacent leg to that of the hypotenuse. For an angle \theta, the sine and cosine functions are denoted simply as \sin \theta and \cos \theta. More generally, the definitions of sine and cosine can be extended to any real number, real value in terms of the lengths of certain line segments in a unit circle. More modern definitions express the sine and cosine as Series (mathematics), infinite series, or as the solutions of certain differential equations, allowing their extension to arbitrary positive and negative values and even to complex numbers. The sine and cosine functions are commonly used to model period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sighting The Pole Star Quadrant
Discovery is the act of detecting something new, or something previously unrecognized as meaningful. With reference to sciences and academic disciplines, discovery is the observation of new phenomena, new actions, or new events and providing new reasoning to explain the knowledge gathered through such observations with previously acquired knowledge from abstract thought and everyday experiences. A discovery may sometimes be based on earlier discoveries, collaborations, or ideas. Some discoveries represent a radical breakthrough in knowledge or technology. New discoveries are acquired through various senses and are usually assimilated, merging with pre-existing knowledge and actions. Questioning is a major form of human thought and interpersonal communication, and plays a key role in discovery. Discoveries are often made due to questions. Some discoveries lead to the invention of objects, processes, or techniques. A discovery may sometimes be based on earlier discoveries, col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Instruments
Astronomical instruments include: *Alidade * Armillary sphere *Astrarium * Astrolabe *Astronomical clock *the Antikythera mechanism, an astronomical clock *Blink comparator *Bolometer *the Canterbury Astrolabe Quadrant *Celatone *Celestial sphere *Charge-coupled device *Computers *CMOS sensor *Coronagraph *Cosmolabe *Dioptra *Equatorial ring *Equatorium * Gnomon * Inclinometer * Interferometer * Kamal *Meridian circle * Microchannel plate detector *Mural instrument *Nebra sky disk *Nocturnal * Octant *Optical spectrometer, a.k.a., Spectrograph *Orrery *Photographic plate *Photometer *Planisphere *the Prague astronomical clock * Quadrant *Reticle *Radio plate *Retroreflector * Scaphe * Sextant * Starshade *Space telescope *Spectrometers *Sundial *Telescope *Torquetum * Triquetrum *Zenith telescope See also *Astronomy *Outline of astronomy *Surveying instrument *Measurement instrument {{DEFAULTSORT:Astronomical instruments Instruments Instrument may refer to: Science and te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexagesimal
Sexagesimal, also known as base 60 or sexagenary, is a numeral system with sixty as its base. It originated with the ancient Sumerians in the 3rd millennium BC, was passed down to the ancient Babylonians, and is still used—in a modified form—for measuring time, angles, and geographic coordinates. The number 60, a superior highly composite number, has twelve factors, namely 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60, of which 2, 3, and 5 are prime numbers. With so many factors, many fractions involving sexagesimal numbers are simplified. For example, one hour can be divided evenly into sections of 30 minutes, 20 minutes, 15 minutes, 12 minutes, 10 minutes, 6 minutes, 5 minutes, 4 minutes, 3 minutes, 2 minutes, and 1 minute. 60 is the smallest number that is divisible by every number from 1 to 6; that is, it is the lowest common multiple of 1, 2, 3, 4, 5, and 6. ''In this article, all sexagesimal digits are represented as decimal numbers, except where otherwise noted. For e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plumb Line
A plumb bob, plumb bob level, or plummet, is a weight, usually with a pointed tip on the bottom, suspended from a string and used as a vertical reference line, or plumb-line. It is a precursor to the spirit level and used to establish a vertical datum. It is typically made of stone, wood, or lead, but can also be made of other metals. If it is used for decoration, it may be made of bone or ivory. The instrument has been used since at least the time of ancient EgyptDenys A. Stocks. Experiments in Egyptian archaeology: stoneworking technology in ncient Egypt'. Routledge; 2003. . p. 180. to ensure that constructions are "plumb", or vertical. It is also used in surveying, to establish the nadir with respect to gravity of a point in space. It is used with a variety of instruments (including levels, theodolites, and steel tapes) to set the instrument exactly over a fixed survey marker or to transcribe positions onto the ground for placing a marker. Etymology The ''plu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arc (geometry)
In mathematics, a curve (also called a curved line in older texts) is an object similar to a line, but that does not have to be straight. Intuitively, a curve may be thought of as the trace left by a moving point. This is the definition that appeared more than 2000 years ago in Euclid's ''Elements'': "The urvedline is the first species of quantity, which has only one dimension, namely length, without any width nor depth, and is nothing else than the flow or run of the point which will leave from its imaginary moving some vestige in length, exempt of any width." This definition of a curve has been formalized in modern mathematics as: ''A curve is the image of an interval to a topological space by a continuous function''. In some contexts, the function that defines the curve is called a ''parametrization'', and the curve is a parametric curve. In this article, these curves are sometimes called ''topological curves'' to distinguish them from more constrained curves such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sun Sight Quadrant
The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radiation, and is the most important source of energy for life on Earth. The Sun's radius is about , or 109 times that of Earth. Its mass is about 330,000 times that of Earth, comprising about 99.86% of the total mass of the Solar System. Roughly three-quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron. The Sun is a G-type main-sequence star (G2V). As such, it is informally, and not completely accurately, referred to as a yellow dwarf (its light is actually white). It formed approximately 4.6 billionAll numbers in this article are short scale. One billion is 109, or 1,000,000,000. years ago from the gravitat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taking The Measure Quadrant
Taking or takings may refer to: * Theft, illicit taking * The acquisition of land under eminent domain * Take (hunting) or taking, an action that adversely affects a species * Kidnapping of persons See also * * * * Take (other) * Taken (other) * Took (other) * Acquisition (other) * Expropriation Nationalization (nationalisation in British English) is the process of transforming privately-owned assets into public assets by bringing them under the public ownership of a national government or state. Nationalization usually refers to pri ... * Resumption (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salat
(, plural , romanized: or Old Arabic ͡sˤaˈloːh, ( or Old Arabic ͡sˤaˈloːtʰin construct state) ), also known as ( fa, نماز) and also spelled , are prayers performed by Muslims. Facing the , the direction of the Kaaba with respect to those praying, Muslims pray first standing and later kneeling or sitting on the ground, reciting prescribed prayers and phrases from the Quran as they bow and prostrate themselves in between. is composed of prescribed repetitive cycles of bows and prostrations, called ( ). The number of s, also known as units of prayer, varies from prayer to prayer. Ritual purity and are prerequisites for performing the prayers. The daily obligatory prayers collectively form the second of the five pillars in Islam, observed three or five times (the latter being the majority) every day at prescribed times. These are usually (observed at dawn), (observed at noon), (observed late in the afternoon), (observed after sunset), and (observed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Front Of Quadrant
Front may refer to: Arts, entertainment, and media Films * ''The Front'' (1943 film), a 1943 Soviet drama film * ''The Front'', 1976 film Music *The Front (band), an American rock band signed to Columbia Records and active in the 1980s and early 1990s *The Front (Canadian band), a Canadian studio band from the 1980s Periodicals * ''Front'' (magazine), a British men's magazine * '' Front Illustrated Paper'', a publication of the Yugoslav People's Army Television * Front TV, a Toronto broadcast design and branding firm * "The Front" (''The Blacklist''), a 2014 episode of the TV series ''The Blacklist'' * "The Front" (''The Simpsons''), a 1993 episode of the TV series ''The Simpsons'' Military * Front (military), a geographical area where armies are engaged in conflict * Front (military formation), roughly, an army group, especially in eastern Europe Places * Front, California, former name of Brown, California * Front, Piedmont, an Italian municipality * The Front, now part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muhammad Ibn Mūsā Al-Khwārizmī
Muḥammad ibn Mūsā al-Khwārizmī ( ar, محمد بن موسى الخوارزمي, Muḥammad ibn Musā al-Khwārazmi; ), or al-Khwarizmi, was a Persians, Persian polymath from Khwarazm, who produced vastly influential works in Mathematics in medieval Islam, mathematics, Astronomy in the medieval Islamic world, astronomy, and Geography and cartography in medieval Islam, geography. Around 820 CE, he was appointed as the astronomer and head of the library of the House of Wisdom in Baghdad.Maher, P. (1998), "From Al-Jabr to Algebra", ''Mathematics in School'', 27(4), 14–15. Al-Khwarizmi's popularizing treatise on algebra (''The Compendious Book on Calculation by Completion and Balancing'', c. 813–833 CEOaks, J. (2009), "Polynomials and Equations in Arabic Algebra", ''Archive for History of Exact Sciences'', 63(2), 169–203.) presented the first systematic solution of linear equation, linear and quadratic equations. One of his principal achievements in algebra was his demon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabic Language
Arabic (, ' ; , ' or ) is a Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C. E.Watson; Walter de Gruyter GmbH & Co. KG, Berlin/Boston, 2011. Having emerged in the 1st century, it is named after the Arab people; the term "Arab" was initially used to describe those living in the Arabian Peninsula, as perceived by geographers from ancient Greece. Since the 7th century, Arabic has been characterized by diglossia, with an opposition between a standard prestige language—i.e., Literary Arabic: Modern Standard Arabic (MSA) or Classical Arabic—and diverse vernacular varieties, which serve as mother tongues. Colloquial dialects vary significantly from MSA, impeding mutual intelligibility. MSA is only acquired through formal education and is not spoken natively. It is the language of literature, official documents, and formal written m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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