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Ya'qub Ibn Tariq
Yaʿqūb ibn Ṭāriq (; referred to by some sources as Yaʿqūb; died ) was a Persian astronomer and mathematician who lived in Baghdad. Career Yaʿqūb ibn Ṭāriq was active in Baghdad as an astronomer during the rule of the second Abbasid caliph, al-Manṣūr (). He seems not to have been aware of Ptolemaic astronomy, and used a Zoroastrian calendar, which consisted of 12 months of 30 days each, with any remaining days being added after the eighth month, Ābān. Yaʿqūb ibn Ṭāriq's treatise dealt with cosmography (the placement and sizes of the heavenly bodies). The estimations of their sizes and distances in were tabulated in the 11th century by the polymath al-Bīrūnī, in his work on India. According to al-Bīrūnī, Yaʿqūb ibn Ṭāriq gave the radius of the Earth as 1,050 , the diameter of the Moon and Mercury as 5,000 (4.8 Earth radii), and the diameter of the other heavenly bodies (Venus, the Sun, Mars, Jupiter, and Saturn) as 20,000 (19.0 Earth radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Islamic Golden Age
The Islamic Golden Age was a period of scientific, economic, and cultural flourishing in the history of Islam, traditionally dated from the 8th century to the 13th century. This period is traditionally understood to have begun during the reign of the Abbasid Caliphate, Abbasid caliph Harun al-Rashid (786 to 809) with the inauguration of the House of Wisdom, which saw Ulama, scholars from all over the Muslim world flock to Baghdad, the world's largest city at the time, to translate the known world's classical knowledge into Arabic and Persian language, Persian. The period is traditionally said to have ended with the collapse of the Abbasid caliphate due to Mongol invasions and conquests, Mongol invasions and the Siege of Baghdad (1258), Siege of Baghdad in 1258. There are a few alternative timelines. Some scholars extend the end date of the golden age to around 1350, including the Timurid Renaissance within it, while others place the end of the Islamic Golden Age as late as the en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alberuni's India
Al-Biruni's ''India'' (), also known by the shortened title ''Kitab al-Hind'', is a book written by Persian polymath Al-Biruni about history, religions, and cultures of India. It was described by the Islamic scholar Annemarie Schimmel as the first objective book on the history of religion. The book was translated into German and afterward to English by Eduard Sachau. Background Biruni's earlier contemporaries, such as Jayhani, the vizier of the Samanid Empire, had described parts of India in his book ''Book of Routes and Kingdoms''; however Biruni considered this and other books by Arab writers marred by the authors' generally superficial knowledge about India and judgemental views on aspects of India they found or suspected to be incompatible with Islam. Biruni and his teacher Abu Nasr Mansur had studied earlier Indian texts on mathematics, such as the '' Sindhind'', benefiting from the historical links between his childhood Khwarazm and India. His book '' Chronology of A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ibn Hibintā
Ibn Hibintā (fl. 950) was a Christian in Iraq known from an Arabic manuscript on Islamic astrology ''al-Mughnī fī aḥkām al-nujūm'', the second part of which is preserved in Munich. Hibinta's lived during the reign of the Buwayhid rulers Ahmad ibn Buwayh (946–949) and ʿAḍūd al-Dawla (949–982) at Baghdad. His only known work, the Kitab al-Mughnī fī aḥkām al-nujūm (literally, the enriching book of the judgement of the stars) includes notes from Ptolemy, Dorotheus of Sidon, al-Khwarizmi and the Indian astrologer Kanaka. A manuscript copy of the second part is held as Arabic Codex 852 at the Bayerische Staatsbibliothek The Bavarian State Library (, abbreviated BSB, called ''Bibliotheca Regia Monacensis'' before 1919) in Munich is the central "State libraries of Germany, Landesbibliothek", i. e. the state library of the Free State of Bavaria, the biggest u ..., Munich. References {{DEFAULTSORT:Hibinta, Ibn Astrologers of the medieval Islamic world ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrologer
Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions of Celestial objects in astrology, celestial objects. Different cultures have employed forms of astrology since at least the 2nd millennium BCE, these practices having originated in Calendrical calculation, calendrical systems used to predict seasonal shifts and to interpret celestial cycles as signs of divine communications. Most, if not all, cultures have attached importance to what they observed in the sky, and some—such as the Hindu astrology, Hindus, Chinese astrology, Chinese, and the Maya civilization, Maya—developed elaborate systems for predicting terrestrial events from celestial observations. Western astrology, one of the oldest astrological systems still in use, can trace its roots to 19th–17th century BCE Mesopotamia, fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Phase
A lunar phase or Moon phase is the apparent shape of the Moon's directly sunlit portion as viewed from the Earth. Because the Moon is tidally locked with the Earth, the same hemisphere is always facing the Earth. In common usage, the four major phases are the new moon, the first quarter, the full moon and the last quarter; the four minor phases are waxing crescent, waxing gibbous, waning gibbous, and waning crescent. A lunar month is the time between successive recurrences of the same phase: due to the eccentricity of the Moon's orbit, this duration is not perfectly constant but averages about 29.5 days. The appearance of the Moon (its phase) gradually changes over a lunar month as the relative orbital positions of the Moon around Earth, and Earth around the Sun, shift. The visible side of the Moon is sunlit to varying extents, depending on the position of the Moon in its orbit, with the sunlit portion varying from 0% (at new moon) to nearly 100% (at full moon). Phenomenon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Astronomy
Astronomy has a long history in the Indian subcontinent, stretching from History of India, pre-historic to History of India (1947–present), modern times. Some of the earliest roots of Indian astronomy can be dated to the period of Indus Valley civilisation or earlier. Astronomy later developed as a discipline of Vedanga, or one of the "auxiliary disciplines" associated with the study of the Vedas dating 1500 BCE or older. The oldest known text is the ''Vedanga Jyotisha'', dated to 1400–1200 BCE (with the extant form possibly from 700 to 600 BCE). Indian astronomy was influenced by Greek astronomy beginning in the 4th century BCEHighlights of Astronomy, Volume 11B: As presented at the XXIIIrd General Assembly of the IAU, 1997. Johannes Andersen Springer, 31 January 1999 – Science – 616 pages. p. 72/ref>Babylon to Voyager and Beyond: A History of Planetary Astronomy. David Leverington. Cambridge University Press, 29 May 2010 – Science – 568 pages. p. 4/ref>Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yazdegerd III
Yazdegerd III (also Romanized as ''Yazdgerd'', ''Yazdgird'') was the last Sasanian Empire, Sasanian King of Kings from 632 to 651. His father was Shahriyar (son of Khosrow II), Shahriyar and his grandfather was Khosrow II. Ascending the throne at the age of eight, the young shah lacked authority and reigned as a figurehead, whilst real power was in the hands of the army commanders, courtiers, and powerful members of the aristocracy, who engaged in internecine warfare. The Sasanian Empire was weakened severely by these internal conflicts, resulting in invasions by the Göktürks from the east, and Khazars from the west. Yazdegerd was unable to contain the Muslim conquest of Persia, Rashidun conquest of Iran, and spent most of his reign fleeing from one province to another in the vain hope of raising an army. Yazdegerd met his end at the hands of a miller near Merv, Marw in 651, bringing an end to the last pre-Islamic Iranian empire after more than 400 years of rule. Etymology Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Persian Language
Persian ( ), also known by its endonym and exonym, endonym Farsi (, Fārsī ), is a Western Iranian languages, Western Iranian language belonging to the Iranian languages, Iranian branch of the Indo-Iranian languages, Indo-Iranian subdivision of the Indo-European languages. Persian is a pluricentric language predominantly spoken and used officially within Iran, Afghanistan, and Tajikistan in three mutual intelligibility, mutually intelligible standard language, standard varieties, respectively Iranian Persian (officially known as ''Persian''), Dari, Dari Persian (officially known as ''Dari'' since 1964), and Tajik language, Tajiki Persian (officially known as ''Tajik'' since 1999).Siddikzoda, S. "Tajik Language: Farsi or not Farsi?" in ''Media Insight Central Asia #27'', August 2002. It is also spoken natively in the Tajik variety by a significant population within Uzbekistan, as well as within other regions with a Persianate society, Persianate history in the cultural sphere o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apogee
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides pertaining to orbits around different bodies have distinct names to differentiate themselves from other apsides. Apsides pertaining to geocentric orbits, orbits around the Earth, are at the farthest point called the ''apogee'', and at the nearest point the ''perigee'', like with orbits of satellites and the Moon around Earth. Apsides pertaining to orbits around the Sun are named ''aphelion'' for the farthest and ''perihelion'' for the nearest point in a heliocentric orbit. Earth's two apsides are the farthest point, ''aphelion'', and the nearest point, ''perihelion'', of its orbit around the host Sun. The terms ''aphelion'' and ''perihelion'' apply in the same way to the orbits of Jupiter and the other planets, the comets, and the asteroids of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitude
Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are imaginary semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, south-east London on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absol ... [...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] |
Mercury (planet)
Mercury is the first planet from the Sun. It is a rocky planet with a trace atmosphere. While it is the List of Solar System objects by size, smallest and least massive planet of the Solar System, its surface gravity is slightly higher than that of Mars. The surface of Mercury is similar to Earth's Moon, heavily Impact crater, cratered, with expansive rupes system, generated from thrust faults, and bright ray systems, formed by ejecta. Its largest crater, Caloris Planitia, has a diameter of , which is about one-third the diameter of the planet (). Being the most inferior planet, inferior orbiting planet it appears in Earth's sky, always close to the Sun, either as a "morning star" or an "evening star". It stays most of the time the closest to all other planets and is the planet with the highest delta-v needed to travel to from all other planets of the Solar System. Mercury's sidereal year (88.0 Earth days) and sidereal day (58.65 Earth days) are in a 3:2 ratio. This relation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
