Medieval Islamic astronomy comprises theastronomical developments made in theIslamic world, particularly during theIslamic Golden Age (9th–13th centuries), and mostly written in theArabic language. These developments mostly took place in theMiddle East,Central Asia,Al-Andalus, andNorth Africa, and later in theFar East andIndia. It closely parallels the genesis of otherIslamic sciences in its assimilation of foreign material and the amalgamation of the disparate elements of that material to create a science withIslamic characteristics. These includedGreek,Sassanid, andIndian works in particular, which were translated and built upon.
Islamic astronomy played a significant role in the revival of ancient astronomy following theloss of knowledge during theearly medieval period, notably with the production ofLatin translations of Arabic worksduring the 12th century.
A significant number of stars in the sky, such asAldebaran,Altair andDeneb, and astronomical terms such asalidade,azimuth, andnadir, are still referred to by theirArabic names. A large corpus of literature from Islamic astronomy remains today, numbering approximately 10,000 manuscripts scattered throughout the world, many of which have not been read or catalogued. Even so, a reasonably accurate picture of Islamic activity in the field of astronomy can be reconstructed.
The Islamic historianAhmad Dallal notes that, unlike theBabylonians,Greeks, andIndians, who had developed elaborate systems of mathematicalastronomical study, thepre-Islamic Arabs relied uponempirical observations. These were based on the rising and setting of particular stars, and this indigenousconstellation tradition was known asAnwā’. The study ofAnwā’ was developed afterIslamization when Arab astronomers introduced mathematics to their study of the night sky.[1]
The first astronomical texts that were translated intoArabic were of Indian[2] and Persian origin.[3] The most notable wasZij al-Sindhind, azij produced byMuḥammad ibn Ibrāhīm al-Fazārī andYaʿqūb ibn Ṭāriq, who translated an 8th-century Indian astronomical work after 770, with the assistance of Indian astronomers who were at the court of caliphAl-Mansur.[2][better source needed]Zij al-Shah was also based upon Indianastronomical tables, compiled in theSasanian Empire over a period of two centuries. Fragments of texts during this period show that Arab astronomers adopted thesine function from India in place of thechords ofarc used inGreek trigonometry.[1]
Ptolemy’s Almagest (a geocentric spherical Earth cosmic model) was translated at least five times in the late eighth and ninth centuries,[4] which was the main authoritative work that informed the Arabic astronomical tradition.[5]
The rise ofIslam, with its obligation to determine the five dailyprayer times and theqibla (the direction towards theKaaba in theSacred Mosque inMecca) inspired intellectual progress in astronomy.[6]
ThephilosopherAl-Farabi (d. 950) described astronomy in terms of mathematics, music, and optics. He showed how astronomy could be used to describe the Earth's motion, and the position and movement of celestial bodies, and separated mathematical astronomy from science, restricting astronomy to describing the position, shape, and size of distant objects.[7] Al-Farabi used the writings ofPtolemy, as described in hisAnalemma, a way of calculating the Sun's position from any fixed location.[8]
TheHouse of Wisdom was an academy established inBaghdad under Abbasid caliphAl-Ma'mun in the early 9th century. Astronomical research was greatly supported by al-Mamun through the House of Wisdom.[citation needed]
The first major Muslim work of astronomy wasZij al-Sindhind, produced by the mathematicianMuhammad ibn Musa al-Khwarizmi in 830. It contained tables for the movements of the Sun, the Moon, and the planetsMercury,Venus,Mars,Jupiter andSaturn. The work introduced Ptolemaic concepts into Islamic science, and marked a turning point in Islamic astronomy, which had previously concentrated on translating works, but which now began to develop new ideas.[9]
In 850, theAbbasid astronomerAl-Farghani wroteKitab fi Jawami ("A compendium of the science of stars"). The book gave a summary of Ptolemiccosmography. However, it also corrected Ptolemy based on the findings of earlier Arab astronomers. Al-Farghani gave revised values for theobliquity of the ecliptic, theprecession of theapogees of the Sun and the Moon, and thecircumference of the Earth. The book was circulated through the Muslim world, and translated intoLatin.[10]
By the 10th century, texts had appeared that doubted that Ptolemy's works were correct.[11] Islamic scholars questioned the Earth's apparent immobility,[12] and position at the centre of the universe, now that independent investigations into thePtolemaic system were possible.[13]
The 10th century Egyptian astronomerIbn Yunus found errors in Ptolemy's calculations. Ptolemy calculated that the Earth's angle ofaxial precession varied by onedegree every 100 years. Ibn Yunus calculated the rate of change to be one degree every 701⁄4 years.[citation needed]
Between 1025 and 1028, thepolymathIbn al-Haytham wrote hisAl-Shukuk ala Batlamyus ("Doubts on Ptolemy"). While not disputing the existence of thegeocentric model, he criticized elements of the Ptolemy's theories. Other astronomers took up the challenge posed in this work, and went on to develop alternate models that resolved the difficulties identified by Ibn al-Haytham. In 1070,Abu Ubayd al-Juzjani published theTarik al-Aflak, in which he discussed the issues arising from Ptolemy's theory ofequants, and proposed a solution. The anonymous workal-Istidrak ala Batlamyus ("Recapitulation regarding Ptolemy"), produced inAl-Andalus, included a list of objections to Ptolemic astronomy.[citation needed]
Nasir al-Din al-Tusi also exposed problems present in Ptolemy's work. In 1261, he published hisTadkhira, which contained 16 fundamental problems he found with Ptolemaic astronomy,[14] and by doing this, set off a chain of Islamic scholars that would attempt to solve these problems. Scholars such asQutb al-Din al-Shirazi, Ibn al-Shatir, andShams al-Din al-Khafri all worked to produce new models for solving Tusi's 16 Problems,[15] and the models they worked to create would become widely adopted by astronomers for use in their own works.
Nasir al-Din Tusi wanted to use the concept of Tusi couple to replace the "equant" concept in Ptolemic model. Since the equant concept would result in the Moon distance to change dramatically through each month, at least by the factor of two if the math is done. But with the Tusi couple, the Moon would just rotate around Earth resulting in the correct observation and applied concept.[16]Mu'ayyad al-Din al-Urdi was another engineer/scholar that tried to make sense of the motion of planets. He came up with the concept of lemma, which is a way of representing the epicyclical motion of planets without using Ptolemic method. Lemma was intended to replace the concept of equant as well.
Abu Rayhan Biruni (b. 973) discussed the possibility of whether the Earth rotated about its own axis and around the Sun, but in hisMasudic Canon, he set forth the principles that the Earth is at the center of the universe and that it has no motion of its own.[17] He was aware that if the Earth rotated on its axis, this would be consistent with his astronomical parameters,[18] but he considered this a problem ofnatural philosophy rather than mathematics.[19]
His contemporary,Abu Sa'id al-Sijzi, accepted that the Earth rotates around its axis.[20] Al-Biruni described anastrolabe invented by Sijzi based on the idea that the earth rotates.[21]
The fact that some people did believe that the Earth is moving on its own axis is further confirmed by an Arabic reference work from the 13th century which states:
According to the geometers [or engineers] (muhandisīn), the earth is in a constant circular motion, and what appears to be the motion of the heavens is actually due to the motion of the earth and not the stars.[19]
At theMaragha andSamarkand observatories, theEarth's rotation was discussed byNajm al-Din al-Qazwini al-Katibi (d. 1277),[22] Tusi (b. 1201) andQushji (b. 1403). The arguments and evidence used by Tusi and Qushji resemble those used by Copernicus to support the Earth's motion.[23][24] However, it remains a fact that the Maragha school never made the big leap toheliocentrism.[25]
In the 12th century, non-heliocentric alternatives to the Ptolemaic system were developed by some Islamic astronomers in al-Andalus, following a tradition established byIbn Bajjah,Ibn Tufail, andIbn Rushd.
A notable example isNur ad-Din al-Bitruji, who considered the Ptolemaic model mathematical, and not physical.[26] Al-Bitruji proposed a theory onplanetary motion in which he wished to avoid bothepicycles and eccentrics.[27] He was unsuccessful in replacing Ptolemy's planetary model, as the numerical predictions of the planetary positions in his configuration were less accurate than those of the Ptolemaic model.[28] One original aspects of al-Bitruji's system is his proposal of a physical cause of celestial motions. He contradicts the Aristotelian idea that there is a specific kind of dynamics for each world, applying instead the same dynamics to the sublunar and the celestial worlds.[29]
In the late 13th century, Nasir al-Din al-Tusi created the Tusi couple, as pictured above. Other notable astronomers from the later medieval period includeMu'ayyad al-Din al-Urdi (c. 1266),Qutb al-Din al-Shirazi (c. 1311),Sadr al-Sharia al-Bukhari (c. 1347),Ibn al-Shatir (c. 1375), andAli Qushji (c. 1474).[30]
In the 15th century, theTimurid rulerUlugh Beg ofSamarkand established his court as a center of patronage for astronomy. He studied it in his youth, and in 1420 ordered the construction of Ulugh Beg Observatory, which produced a new set of astronomical tables, as well as contributing to other scientific and mathematical advances.[31]
Several major astronomical works were produced in the early 16th century, including ones byAl-Birjandi (d. 1525 or 1526) and Shams al-Din al-Khafri (fl. 1525). However, the vast majority of works written in this and later periods in the history of Islamic sciences are yet to be studied.[24]
Islamic astronomy influencedMalian astronomy.[32]
Several works of Islamic astronomy were translated to Latinstarting from the 12th century.
The work ofal-Battani (d. 929),Kitāb az-Zīj ("Book ofAstronomical Tables"), was frequently cited by European astronomers and received several reprints, including one with annotations byRegiomontanus.[33]Nicolaus Copernicus, in his book that initiated theCopernican Revolution, theDe revolutionibus orbium coelestium, mentioned al-Battani no fewer than 23 times,[34] and also mentions him in theCommentariolus.[35]Tycho Brahe,Giovanni Battista Riccioli,Johannes Kepler,Galileo Galilei, and others frequently cited him or his observations.[36] His data is still used in geophysics.[37]
Around 1190,al-Bitruji published an alternative geocentric system to Ptolemy's model. His system spread through most of Europe during the 13th century, with debates and refutations of his ideas continued to the 16th century.[26] In 1217,Michael Scot finished a Latin translation of al-Bitruji'sBook of Cosmology (Kitāb al-Hayʾah), which became a valid alternative to Ptolemy'sAlmagest inscholasticist circles.[29] Several European writers, includingAlbertus Magnus andRoger Bacon, explained it in detail and compared it with Ptolemy's.[26] Copernicus cited his system in theDe revolutionibus while discussing theories of the order of the inferior planets.[26][29]
Some historians maintain that the thought of the Maragheh observatory, in particular the mathematical devices known as theUrdi lemma and the Tusi couple, influenced Renaissance-era European astronomy and thus Copernicus.[38][39][40][41] Copernicus used such devices in the same planetary models as found in Arabic sources.[42] Furthermore, the exact replacement of theequant by twoepicycles used by Copernicus in theCommentariolus was found in an earlier work by Ibn al-Shatir (d.c. 1375) of Damascus.[43] Copernicus' lunar and Mercury models are also identical to Ibn al-Shatir's.[44]
While the influence of the criticism of Ptolemy byAverroes on Renaissance thought is clear and explicit, the claim of direct influence of the Maragha school, postulated byOtto E. Neugebauer in 1957, remains an open question.[25][45][46] Since the Tusi couple was used by Copernicus in his reformulation of mathematical astronomy, there is a growing consensus that he became aware of this idea in some way. It has been suggested[47][48] that the idea of the Tusi couple may have arrived in Europe leaving few manuscript traces, since it could have occurred without the translation of any Arabic text into Latin. One possible route of transmission may have been throughByzantine science, which translated some ofal-Tusi's works from Arabic intoByzantine Greek. Several Byzantine Greek manuscripts containing the Tusi-couple are still extant in Italy.[49] Other scholars have argued that Copernicus could well have developed these ideas independently of the late Islamic tradition.[50] Copernicus explicitly references several astronomers of the "Islamic Golden Age" (10th to 12th centuries) inDe Revolutionibus: Albategnius (Al-Battani), Averroes (Ibn Rushd),Thebit (Thābit ibn Qurra),Arzachel (Al-Zarqali), and Alpetragius (Al-Bitruji), but he does not show awareness of the existence of any of the later astronomers of the Maragha school.[35]
It has been argued that Copernicus could have independently discovered the Tusi couple or took the idea fromProclus'sCommentary on the First Book ofEuclid,[51] which Copernicus cited.[52]
Another possible source for Copernicus's knowledge of this mathematical device is theQuestiones de Spera ofNicole Oresme, who described how a reciprocating linear motion of a celestial body could be produced by a combination of circular motions similar to those proposed by al-Tusi.[53]
Islamic influence on Chinese astronomy was first recorded during theSong dynasty when aHuiMuslim astronomer namedMa Yize introduced the concept of seven days in a week and made other contributions.[54]
Islamic astronomers werebrought to China in order to work on calendar making and astronomy during theMongol Empire and the succeedingYuan dynasty.[55] The Chinese scholarYeh-lu Chu'tsai accompaniedGenghis Khan to Persia in 1210 and studied their calendar for use in the Mongol Empire.[55]Kublai Khan brought Iranians toBeijing to construct an observatory and an institution for astronomical studies.[56]
Several Chinese astronomers worked at the Maragheh observatory, founded by Nasir al-Din al-Tusi in 1259 under the patronage ofHulagu Khan in Persia.[57] One of these Chinese astronomers was Fu Mengchi, or Fu Mezhai.[58] In 1267, the Persian astronomerJamal ad-Din, who previously worked at Maragha observatory, presented Kublai Khan with sevenPersian astronomical instruments, including a terrestrialglobe and anarmillary sphere,[59] as well as an astronomicalalmanac, which was later known in China as theWannian Li ("Ten Thousand Year Calendar" or "Eternal Calendar"). He was known as "Zhamaluding" in China, where, in 1271,[58] he was appointed by Khan as the first director of the Islamic observatory in Beijing,[57] known as the Islamic Astronomical Bureau, which operated alongside the Chinese Astronomical Bureau for four centuries. Islamic astronomy gained a good reputation in China for its theory of planetarylatitudes, which did not exist in Chinese astronomy at the time, and for its accurate prediction of eclipses.[60]
Some of the astronomical instruments constructed by the famous Chinese astronomerGuo Shoujing shortly afterwards resemble the style of instrumentation built at Maragheh.[57] In particular, the "simplified instrument" (jianyi) and the largegnomon at theGaocheng Astronomical Observatory show traces of Islamic influence.[60] While formulating theShoushili calendar in 1281, Shoujing's work inspherical trigonometry may have also been partially influenced byIslamic mathematics, which was largely accepted at Kublai's court.[61] These possible influences include a pseudo-geometrical method for converting betweenequatorial andecliptic coordinates, the systematic use ofdecimals in the underlying parameters, and the application ofcubic interpolation in the calculation of the irregularity in the planetary motions.[60]
Hongwu Emperor (r. 1368–1398) of theMing dynasty (1328–1398), in the first year of his reign (1368), conscripted Han and non-Han astrology specialists from the astronomical institutions in Beijing of the former Mongolian Yuan toNanjing to become officials of the newly established national observatory.
That year, the Ming government summoned for the first time the astronomical officials to come south from the upper capital of Yuan. There were fourteen of them. In order to enhance accuracy in methods of observation and computation, Hongwu Emperor reinforced the adoption of parallel calendar systems, theHan and the Hui. In the following years, the Ming Court appointed several Hui astrologers to hold high positions in the Imperial Observatory. They wrote many books on Islamic astronomy and also manufactured astronomical equipment based on the Islamic system.
The translation of two important works into Chinese was completed in 1383: Zij (1366) and al-Madkhal fi Sina'at Ahkam al-Nujum,Introduction to Astrology (1004).
In 1384, a Chinese astrolabe was made for observing stars based on the instructions for making multi-purposed Islamic equipment. In 1385, the apparatus was installed on a hill in northern Nanjing.
Around 1384, during the Ming dynasty, Hongwu Emperor ordered theChinese translation and compilation of Islamic astronomical tables, a task that was carried out by the scholarsMashayihei, a Muslim astronomer, andWu Bozong, a Chinese scholar-official. These tables came to be known as theHuihui Lifa (Muslim System of Calendrical Astronomy), which was published in China a number of times until the early 18th century,[62] though theQing dynasty had officially abandoned the tradition of Chinese-Islamic astronomy in 1659.[63] The Muslim astronomerYang Guangxian was known for his attacks on the Jesuit's astronomical sciences.
In the earlyJoseon, theIslamic calendar served as a basis for calendar reform being more accurate than the existing Chinese-based calendars.[64] A Korean translation of theHuihui Lifa, a text combiningChinese astronomy with Islamic astronomy works of Jamal ad-Din, was studied in Joseon Korea during the time ofSejong the Great in the 15th century.[65]
The first systematic observations in Islam are reported to have taken place under the patronage of al-Mamun. Here, and in many other private observatories from Damascus to Baghdad,meridiandegree measurement were performed (al-Ma'mun's arc measurement), solar parameters were established, and detailed observations of the Sun,Moon, andplanets were undertaken.
During the 10th century, theBuwayhid dynasty encouraged the undertaking of extensive works in astronomy; such as the construction of a large-scale instruments with which observations were made in the year 950. This is known through recordings made in the zij of astronomers such asIbn al-A'lam. The great astronomerAbd al-Rahman al-Sufi was patronised by prince'Adud al-Dawla, who systematically revised Ptolemy's catalogue ofstars.Sharaf al-Dawla also established a similar observatory in Baghdad. Reports by Ibn Yunus andal-Zarqali inToledo andCordoba indicate the use of sophisticated instruments for their time.
It wasMalik Shah I who established the first large observatory, probably inIsfahan. It was here whereOmar Khayyám with many other collaborators constructed a zij and formulated thePersian Solar Calendar a.k.a. thejalali calendar. A modern version of this calendar, theSolar Hijri calendar, is still in official use inIran andAfghanistan today.
The most influential observatory was however founded byHulegu Khan during the 13th century. Here, Nasir al-Din al-Tusi supervised its technical construction atMaragha. The facility contained resting quarters for Hulagu Khan, as well as a library and mosque. Some of the top astronomers of the day gathered there, and from their collaboration resulted important modifications to the Ptolemaic system over a period of 50 years.
In 1420, prince Ulugh Beg, himself an astronomer and mathematician, founded another large observatory in Samarkand, the remains of which were excavated in 1908 by Russian teams.
And finally,Taqi al-Din Muhammad ibn Ma'ruf founded alarge observatory inOttomanConstantinople in 1577, which was on the same scale as those in Maragha and Samarkand. The observatory was short-lived however, as opponents of the observatory and prognostication from the heavens prevailed and the observatory was destroyed in 1580.[66] While the Ottoman clergy did not object to the science of astronomy, the observatory was primarily being used forastrology, which they did oppose, and successfully sought its destruction.[67]
As observatory development continued, Islamicate scientists began to pioneer the planetarium. The major difference between a planetarium and an observatory is how the universe is projected. In an observatory, viewers look up into the night sky, on the other hand, planetariums allow for universes planets and stars to project at eye-level in a room. Scientist Ibn Firnas, created a planetarium in his home that included artificial storm noises and was completely made of glass.
Our knowledge of the instruments used by Muslim astronomers primarily comes from two sources: first the remaining instruments in private and museum collections today, and second the treatises and manuscripts preserved from the Middle Ages.Muslim astronomers of the "Golden Period" made many improvements to instruments already in use before their time, such as adding new scales or details.
Celestial globes were used primarily for solving problems in celestial astronomy. Today, 126 such instruments remain worldwide, the oldest from the 11th century. The altitude of the Sun, or theRight Ascension andDeclination of stars could be calculated with these by inputting the location of the observer on the meridian ring of the globe.[68] The initial blueprint for a portable celestial globe to measure celestial coordinates came from Spanish Muslim astronomerJabir ibn Aflah (d. 1145). Another skillful Muslim astronomer working on celestial globes wasAbd al-Rahman al-Sufi (b. 903), whose treatise theBook of Fixed Stars describes how to design the constellation images on the globe, as well as how to use the celestial globe. However, it was in Iraq in the 10th century that astronomer Al-Battani was working on celestial globes to record celestial data. This was different because up until then, the traditional use for a celestial globe was as an observational instrument. Al-Battani's treatise describes in detail the plotting coordinates for 1,022 stars, as well as how the stars should be marked. An armillary sphere had similar applications. No early Islamic armillary spheres survive, but several treatises on "the instrument with the rings" were written. In this context there is also an Islamic development, the spherical astrolabe, of which only one complete instrument, from the 14th century, has survived.
Brass astrolabes were an invention of Late Antiquity. The first Islamic astronomer reported as having built an astrolabe isMuhammad al-Fazari (late 8th century).[69] Astrolabes were popular in theIslamic world during the "Golden Age", chiefly as an aid to finding the qibla. The earliest known example is dated to 927/8 (AH 315).[70]
The device was incredibly useful, and sometime during the 10th century it was brought to Europe from the Muslim world, where it inspired Latin scholars to take up an interest in both math and astronomy.[71][failed verification]
The largest function of the astrolabe is it serves as a portable model of space that can calculate the approximate location of any heavenly body found within theSolar System at any point in time, provided the latitude of the observer is accounted for. In order to adjust for latitude, astrolabes often had a second plate on top of the first, which the user could swap out to account for their correct latitude.[71] One of the most useful features of the device is that the projection created allows users to calculate and solve mathematical problems graphically which could otherwise be done only by using complex spherical trigonometry, allowing for earlier access to great mathematical feats.[72] In addition to this, use of the astrolabe allowed for ships at sea to calculate their position given that the device is fixed upon a star with a known altitude. Standard astrolabes performed poorly on the ocean, as bumpy waters and aggressive winds made use difficult, so a new iteration of the device, known as aMariner's astrolabe, was developed to counteract the difficult conditions of the sea.[73]
The instruments were used to read the time of the Sun rising and fixed stars. al-Zarqali ofAndalusia constructed one such instrument in which, unlike its predecessors, did not depend on the latitude of the observer, and could be used anywhere. This instrument became known in Europe as the Saphea.[74]
The astrolabe was arguably the most important instrument created and used for astronomical purposes in the medieval period. Its invention in early medieval times required immense study and much trial and error in order to find the right method of which to construct it to where it would work efficiently and consistently, and its invention led to several mathematic advances which came from the problems that arose from using the instrument.[75] The astrolabe's original purpose was to allow one to find the altitudes of the sun and many visible stars, during the day and night, respectively.[76] However, they have ultimately come to provide great contribution to the progress of mapping the globe, thus resulting in further exploration of the sea, which then resulted in a series of positive events that allowed the world we know today to come to be.[77] The astrolabe has served many purposes over time, and it has shown to be quite a key factor from medieval times to the present.
The astrolabe required the use of mathematics, and the development of the instrument incorporated azimuth circles, which opened a series of questions on further mathematical dilemmas.[75] Astrolabes served the purpose of finding the altitude of the sun, which also meant that they provided one the ability to find the direction of Muslim prayer (or the direction of Mecca).[75] Aside from these purposes, the astrolabe had a great influence on navigation, specifically in the marine world. This advancement made the calculation of latitude simpler, which led to an increase in sea exploration, and indirectly led to the Renaissance revolution, an increase in global trade activity, and ultimately the discovery of several of the world's continents.[77]
Abu Rayhan Biruni designed an instrument he called "Box of the Moon", which was amechanicallunisolar calendar, employing agear train and eightgear-wheels.[78] This was an early example of a fixed-wired knowledge processingmachine.[79] This work of Al Biruni uses the same gear trains preserved in a 6th century Byzantine portable sundial.[80]
Muslims made several important improvements[which?] to the theory and construction ofsundials, which they inherited from their Indian andGreek predecessors.Khwarizmi made tables for these instruments which considerably shortened the time needed to make specific calculations.
Sundials were frequently placed on mosques to determine the time of prayer. One of the most striking examples was built in the 14th century by themuwaqqit (timekeeper) of the Umayyad Mosque in Damascus, ibn al-Shatir.[82]
Several forms ofquadrants were invented by Muslims. Among them was the sine quadrant used for astronomical calculations, and various forms of the horary quadrant used to determine the time (especially the times of prayer) by observations of the Sun or stars. A center of the development of quadrants was 9th century Baghdad.[83] Abu Bakr ibn al-Sarah al-Hamawi (d. 1329) was a Syrian astronomer that invented a quadrant called “al-muqantarat al-yusra”. He devoted his time to writing several books on his accomplishments and advancements with quadrants and geometrical problems. His works on quadrants includeTreatise on Operations with the Hidden Quadrant andRare Pearls on Operations with the Circle for Finding Sines. These instruments could measure the altitude between a celestial object and the horizon. However, as Muslim astronomers used them, they began to find other ways to use them. For example, the mural quadrant, for recording the angles of planets and celestial bodies. Or the universal quadrant, for latitude solving astronomical problems. The horary quadrant, for finding the time of day with the sun. The almucantar quadrant, which was developed from the astrolabe.
Planetaryequatoria were probably made by ancient Greeks, although no findings nor descriptions have been preserved from that period. In his comment on Ptolemy'sHandy Tables, 4th century mathematicianTheon of Alexandria introduced some diagrams to geometrically compute the position of the planets based on Ptolemy's epicyclical theory. The first description of the construction of a solar (as opposed to planetary) equatorium is contained in Proclus's 5th century workHypotyposis,[84] where he gives instructions on how to construct one in wood or bronze.[85]
The earliest known description of a planetary equatorial is contained in early 11th century treatise byIbn al-Samh, preserved only as a 13th-century Castillian translation contained in theLibros del saber de astronomia (Books of the knowledge of astronomy); the same book contains also a 1080/1081 treatise on the equatorial byAl-Zarqali.[85]
Examples of cosmological imagery in Islamic art can be found in objects such asmanuscripts, astrological tools, and palacefrescoes, and the study of the heavens by Islamic astronomers has translated into artistic representations of the universe and astrological concepts.[86] The Islamic world gleaned inspiration from Greek, Iranian, and Indian traditions to represent the stars and the universe.[87]
Thedesert castle atQasr Amra, which was used as aUmayyad palace, has a bath dome decorated with the Islamic zodiac and other celestial designs.[88]
The Islamic zodiac and astrological visuals can be seen in examples of metalwork.Ewers depicting the twelve zodiac symbols exist in order to emphasize elite craftsmanship and carry blessings such as one example now at the Metropolitan Museum of Art.[89] Coinage also carried zodiac imagery that bears the sole purpose of representing the month in which the coin was minted.[90] As a result, astrological symbols could have been used as both decoration, and a means to communicate symbolic meanings or specific information.
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Some of the below are from Hill (1993),Islamic Science And Engineering'.[91]
{{cite book}}: CS1 maint: publisher location (link){{cite book}}:|work= ignored (help)We can also see Muslim influence in the official calendars of the late Goryeo period. After they gained control of China, the Mongols invited Arab astronomers to Beijing to correct mistakes that had crept into Chinese calculations of the movements of the sun, the moon, the five visible planets, and the stars. Those Muslim scientists brought with them the latest astronomical instruments as well as mathematical tools for predicting heavenly movements based on what those instruments revealed. The Korean government then sent their own astronomers to Beijing to learn from those Muslims. Even though there was nothing particularly religious about the calendar those Muslim scientists produced for East Asia, it became known unofficially as the Muslim Calendar. The government in both China and Korea continued to use Muslim calendrical techniques until the 16th century, when Christian missionaries from Europe brought even more advanced instruments and calculating techniques to China.
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