Astronomy in medieval islam

An 18th-century Persian astrolabe, kept at the Whipple Museum of the History of Science in Cambridge, England.

Islamic astronomy comprises the astronomical developments made in the Islamic world, particularly during the Islamic Golden Age (8th–15th centuries),[1] and mostly written in the Arabic language. These developments mostly took place in the Middle East, Central Asia, Al-Andalus, and North Africa, and later in the Far East and India. It closely parallels the genesis of other Islamic sciences in its assimilation of foreign material and the amalgamation of the disparate elements of that material to create a science with Islamic characteristics. These included Greek, Sassanid, and Indian works in particular, which were translated and built upon.[2] In turn, Islamic astronomy later had a significant influence on Byzantine[3] and European[4] astronomy (see Latin translations of the 12th century) as well as Chinese astronomy[5] and Malian astronomy.[6][7]

A significant number of stars in the sky, such as Aldebaran and Altair, and astronomical terms such as alidade, azimuth, and almucantar, are still referred to by their Arabic names.[8][9] 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.[10]


Muhammad Salih Tahtawi of Sindh headed the task of creating a massive, seamless celestial globe using a secret wax casting method in the Mughal Empire, the famous celestial globe of Muhammad Salih Tahtawi is inscribed with Arabic and Persian inscriptions and was completed in the year 1631.[11]


Ahmad Dallal notes that, unlike the Babylonians, Greeks, and Indians, who had developed elaborate systems of mathematical astronomical study, the pre-Islamic Arabs relied entirely on empirical observations. These observations were based on the rising and setting of particular stars, and this area of astronomical study was known as anwa. Anwa continued to be developed after Islamization by the Arabs, where Islamic astronomers added mathematical methods to their empirical observations.[12] According to David King, after the rise of Islam, the religious obligation to determine the qibla and prayer times inspired more progress in astronomy for centuries.[13]

Donald Hill (1993) divided Islamic Astronomy into the four following distinct time periods in its history:


The period of assimilation and syncretisation of earlier Hellenistic, Indian, and Sassanid astronomy.

The first astronomical texts that were translated into Arabic were of Indian and Persian origin.[14] The most notable of the texts was Zij al-Sindhind,[n 1] an 8th-century Indian astronomical work that was translated by Muhammad ibn Ibrahim al-Fazari and Yaqub ibn Tariq after 770 CE under the supervision of an Indian astronomer who visited the court of caliph Al-Mansur in 770. Another text translated was the Zij al-Shah, a collection of astronomical tables (based on Indian parameters) compiled in Sasanid Persia over two centuries. Fragments of texts during this period indicate that Arabs adopted the sine function (inherited from India) in place of the chords of arc used in Greek trigonometry.[12]


The Tusi-couple is a mathematical device invented by Nasir al-Din al-Tusi in which a small circle rotates inside a larger circle twice the diameter of the smaller circle. Rotations of the circles cause a point on the circumference of the smaller circle to oscillate back and forth in linear motion along a diameter of the larger circle.

This period of vigorous investigation, in which the superiority of the Ptolemaic system of astronomy was accepted and significant contributions made to it. However, Dallal notes that the use of parameters, s