Ahmad Ibn Muhammad Ibn Kathir Al-Farghani
Abū al-ʿAbbās Aḥmad ibn Muḥammad ibn Kathīr al-Farghānī ( ar, أبو العبّاس أحمد بن محمد بن كثير الفرغاني 798/800/805–870), also known as Alfraganus in the West, was an astronomer in the Abbasid court in Baghdad, and one of the most famous astronomers in the 9th century. Al-Farghani composed several works on astronomy and astronomical equipment that were widely distributed in Arabic and Latin and were influential to many scientists. His best known work, ''Kitāb fī Jawāmiʿ ʿIlm al-Nujūmi'' (whose name translates to ''Elements of astronomy on the celestial motions''), was an extensive summary of Ptolemy's Almagest containing revised experimental data. Christopher Columbus, used Al Farghani’s calculations for his voyages to America. In addition to making substantial contributions to astronomy, al-Farghani also worked as an engineer, supervising construction projects on rivers in Cairo, Egypt. The lunar crater ''Alfraganus'' is name ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cairo
Cairo ( ; ar, القاهرة, al-Qāhirah, ) is the capital of Egypt and its largest city, home to 10 million people. It is also part of the largest urban agglomeration in Africa, the Arab world and the Middle East: The Greater Cairo metropolitan area, with a population of 21.9 million, is the 12th-largest in the world by population. Cairo is associated with ancient Egypt, as the Giza pyramid complex and the ancient cities of Memphis and Heliopolis are located in its geographical area. Located near the Nile Delta, the city first developed as Fustat, a settlement founded after the Muslim conquest of Egypt in 640 next to an existing ancient Roman fortress, Babylon. Under the Fatimid dynasty a new city, ''al-Qāhirah'', was founded nearby in 969. It later superseded Fustat as the main urban centre during the Ayyubid and Mamluk periods (12th–16th centuries). Cairo has long been a centre of the region's political and cultural life, and is titled "the city of a thousand m ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Quva
Quva (Uzbek: Quva/Қува, قباء; Tajik: Фарғона, Persian: قباء Quva; Russian: Кува) is the capital of Quva District in eastern Uzbekistan. Quva is about 450 km east of Tashkent, about 46 km west of Andijan, and less than 17 km from the Kyrgyzstan border. Its population is 46,400 (2016). Quva is motherland of Al-Farghani, Abū al-ʿAbbās Aḥmad ibn Muḥammad ibn Kathīr al-Farghānī, (800/805–870) also known as Alfraganus in the West, was an astronomer in the Abbasid court in Baghdad, and one of the most famous astronomers in the 9th century. The lunar crater ''Alfraganus'' is named after him. Quva also famous with its fruits pomegranates, cherries and peaches. In addition, there is a big water reservoir ''Karkidon',' translated means hippopotamus and South Ferghana Canal in the territory of Quva. Neighbouring with the Marhamat district of Andijan region. Kuva district is an administrative unit, the easternmost region of the Ferghana regio ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Nilometer
A nilometer was a structure for measuring the Nile River's clarity and water level during the annual flood season. There were three main types of nilometers, calibrated in Egyptian cubits: (1) a vertical column, (2) a corridor stairway of steps leading down to the Nile, or (3) a deep well with culvert. If the water level was low, the fertility of the floodplain would suffer. If it was too high, the flooding would be destructive. There was a specific mark that indicated how high the flood should be if the fields were to get good soil. Nilometers originated in Pharaonic times, were also built in Roman times, and were used until the Aswan Dam rendered them obsolete in the 1960s. Description Between July and November, the reaches of the Nile running through Egypt would burst their banks and cover the adjacent floodplain. When the waters receded, around September or October, they left behind a rich alluvial deposit of exceptionally fertile black silt over the croplands. The ''akhet'' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Baghdad
Baghdad (; ar, بَغْدَاد , ) is the capital of Iraq and the second-largest city in the Arab world after Cairo. It is located on the Tigris near the ruins of the ancient city of Babylon and the Sassanid Persian capital of Ctesiphon. In 762 CE, Baghdad was chosen as the capital of the Abbasid Caliphate, and became its most notable major development project. Within a short time, the city evolved into a significant cultural, commercial, and intellectual center of the Muslim world. This, in addition to housing several key academic institutions, including the House of Wisdom, as well as a multiethnic and multi-religious environment, garnered it a worldwide reputation as the "Center of Learning". Baghdad was the largest city in the world for much of the Abbasid era during the Islamic Golden Age, peaking at a population of more than a million. The city was largely destroyed at the hands of the Mongol Empire in 1258, resulting in a decline that would linger through many c ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Al-Ma'mūn
Abu al-Abbas Abdallah ibn Harun al-Rashid ( ar, أبو العباس عبد الله بن هارون الرشيد, Abū al-ʿAbbās ʿAbd Allāh ibn Hārūn ar-Rashīd; 14 September 786 – 9 August 833), better known by his regnal name Al-Ma'mun ( ar, المأمون, al-Maʾmūn), was the seventh Abbasid caliph, who reigned from 813 until his death in 833. He succeeded his half-brother al-Amin after a civil war, during which the cohesion of the Abbasid Caliphate was weakened by rebellions and the rise of local strongmen; much of his domestic reign was consumed in pacification campaigns. Well educated and with a considerable interest in scholarship, al-Ma'mun promoted the Translation Movement, the flowering of learning and the sciences in Baghdad, and the publishing of al-Khwarizmi's book now known as "Algebra". He is also known for supporting the doctrine of Mu'tazilism and for imprisoning Imam Ahmad ibn Hanbal, the rise of religious persecution (''mihna''), and for the resump ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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List Of Abbasid Caliphs
The Abbasid caliphs were the holders of the Islamic title of caliph who were members of the Abbasid dynasty, a branch of the Quraysh tribe descended from the uncle of the Islamic prophet Muhammad, Al-Abbas ibn Abd al-Muttalib. The family came to power in the Abbasid Revolution in 748–750, supplanting the Umayyad Caliphate. They were the rulers of the Abbasid Caliphate, as well as the generally recognized ecumenical heads of Islam, until the 10th century, when the Shi'a Fatimid Caliphate (established in 909) and the Caliphate of Córdoba (established in 929) challenged their primacy. The political decline of the Abbasids had begun earlier, during the Anarchy at Samarra (861–870), which accelerated the fragmentation of the Muslim world into autonomous dynasties. The caliphs lost their temporal power in 936–946, first to a series of military strongmen, and then to the Shi'a Buyid Emirs that seized control of Baghdad; the Buyids were in turn replaced by the Sunni Seljuk Turks i ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Abbasid Caliphate
The Abbasid Caliphate ( or ; ar, الْخِلَافَةُ الْعَبَّاسِيَّة, ') was the third caliphate to succeed the Islamic prophet Muhammad. It was founded by a dynasty descended from Muhammad's uncle, Abbas ibn Abdul-Muttalib (566–653 CE), from whom the dynasty takes its name. They ruled as caliphs for most of the caliphate from their capital in Baghdad in modern-day Iraq, after having overthrown the Umayyad Caliphate in the Abbasid Revolution of 750 CE (132 AH). The Abbasid Caliphate first centered its government in Kufa, modern-day Iraq, but in 762 the caliph Al-Mansur founded the city of Baghdad, near the ancient Babylonian capital city of Babylon. Baghdad became the center of science, culture and invention in what became known as the Golden Age of Islam. This, in addition to housing several key academic institutions, including the House of Wisdom, as well as a multiethnic and multi-religious environment, garnered it a worldwide reputation as the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Meridian Arc
In geodesy and navigation, a meridian arc is the curve between two points on the Earth's surface having the same longitude. The term may refer either to a segment of the meridian, or to its length. The purpose of measuring meridian arcs is to determine a figure of the Earth. One or more measurements of meridian arcs can be used to infer the shape of the reference ellipsoid that best approximates the geoid in the region of the measurements. Measurements of meridian arcs at several latitudes along many meridians around the world can be combined in order to approximate a ''geocentric ellipsoid'' intended to fit the entire world. The earliest determinations of the size of a spherical Earth required a single arc. Accurate survey work beginning in the 19th century required several arc measurements in the region the survey was to be conducted, leading to a proliferation of reference ellipsoids around the world. The latest determinations use astro-geodetic measurements and the methods of ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Measurement
Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared to a basic reference quantity of the same kind. The scope and application of measurement are dependent on the context and discipline. In natural sciences and engineering, measurements do not apply to nominal properties of objects or events, which is consistent with the guidelines of the ''International vocabulary of metrology'' published by the International Bureau of Weights and Measures. However, in other fields such as statistics as well as the social and behavioural sciences, measurements can have multiple levels, which would include nominal, ordinal, interval and ratio scales. Measurement is a cornerstone of trade, science, technology and quantitative research in many disciplines. Historically, many measurement systems existed fo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surface is made up of the ocean, dwarfing Earth's polar ice, lakes, and rivers. The remaining 29% of Earth's surface is land, consisting of continents and islands. Earth's surface layer is formed of several slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth's liquid outer core generates the magnetic field that shapes the magnetosphere of the Earth, deflecting destructive solar winds. The atmosphere of the Earth consists mostly of nitrogen and oxygen. Greenhouse gases in the atmosphere like carbon dioxide (CO2) trap a part of the energy from the Sun close to the surface. Water vapor is widely present in the atmosphere and forms clouds that cover most of the planet. More solar e ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length d of a diameter is also called the diameter. In this sense one speaks of diameter rather than diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r. :d = 2r \qquad\text\qquad r = \frac. For a convex shape in the plane, the diameter is defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary, and the is often defined to be the smallest such distance. Both quantities can be calculated efficiently using rotating calipers. For a curve of constant width such as the Reuleaux triangle, the width and diameter are the same because all ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Calculation
A calculation is a deliberate mathematical process that transforms one or more inputs into one or more outputs or ''results''. The term is used in a variety of senses, from the very definite arithmetical calculation of using an algorithm, to the vague heuristics of calculating a strategy in a competition, or calculating the chance of a successful relationship between two people. For example, multiplying 7 by 6 is a simple algorithmic calculation. Extracting the square root or the cube root of a number using mathematical models is a more complex algorithmic calculation. Statistical estimations of the likely election results from opinion polls also involve algorithmic calculations, but produces ranges of possibilities rather than exact answers. To ''calculate'' means to determine mathematically in the case of a number or amount, or in the case of an abstract problem to deduce the answer usin ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |