Thābit ibn Qurra

transl|ar|ALA|Al-Ṣābiʾ Thābit ibn Qurra al-Ḥarrānī (836 in Harran, Mesopotamia – February 18, 901 in Baghdad) was an Arab astronomer, mathematician and physician who was known as Thebit in Latin.

Biography

Thabit was born in Harran (known as Carrhae in antiquity) in Mesopotamia (in modern day Turkey). At the invitation of Muhammad bin Musa bin Shakir, one of the Banu Musa brothers, Thabit went to study in Baghdad at the House of Wisdom. He belonged to the sect of the Sabians of Harran, a sect of Hermeticists, [(Churton p. 27)] often confused with the Mandaeans. As star-worshippers, Sabians showed a great interest in astronomy, astrology, magic, and mathematics. This sect lived in the vicinity of the main center of the Caliphate until 1258, when the Mongols destroyed their last shrine. During Muslim rule, they were a protected minority, and around the time of al-Mutawakkil's reign their town became a center for philosophical, esoteric, and medical learning. They were joined by the descendants of pagan Greek scholars who, having been persecuted in Europe, settled in lands that became part of the Abbasid caliphate. The Muslims were greatly interested in Greek culture and science, collecting and translating many ancient Greek works in the fields of philosophy and mathematics. Although they later became Arabic speakers, in pre-Islamic times, it was common for Sabians to speak Greek.

Thabit and his pupils lived in the midst of the most intellectually vibrant, and probably the largest, city of the time, Baghdad. He occupied himself with mathematics, astronomy, astrology, magic, mechanics, medicine, and philosophy. His native language was Syriac, which was the eastern Aramaic dialect from Edessa, and he knew Greek well too. He translated from Greek Apollonius, Archimedes, Euclid and Ptolemy. Thabit had revised the translation of Euclid's Elements of Hunayn ibn Ishaq. He had also rewritten Hunayn's translation of Ptolemy's "Almagest" and translated Ptolemy's "Geography", which later became very well-known. Thabit's translation of a work by Archimedes which gave a construction of a regular heptagon was discovered in the 20th century, the original having been lost.

Later in his life, Thabit's patron was the Abbasid Caliph al-Mu'tadid (reigned 892–902). Thabit became the Caliph's personal friend and courtier.

Thabit died in Baghdad. After him the greatest Sabean name was Abu Abdallah Mohammad ibn Jabir Al-Battani. Thabit and his grandson Ibrahim ibn Sinan ibn Thabit studied the curves needed for making sundials. Thabit's son Sinan ibn Thabit was a distinguished physician who was responsible for supervising all the public hospitals of Baghdad.

Works

Only a few of Thabit's works are preserved in their original form.

The medieval astronomical theory of the trepidation of the equinoxes is often attributed to Thabit. But it had already been described by Theon of Alexandria in his comments of the "Handy Tables" of Ptolemaeus. According to Copernicus Thabit determined the length of the sidereal year as 365 days, 6 hours, 9 minutes and 12 seconds (an error of 2 seconds). Copernicus based his claim on the Latin text attributed to Thabit. Thabit published his observations of the Sun.

In mathematics, Thabit discovered an equation for determining the amicable numbers. He also wrote on the theory of numbers, and extended their use to describe the ratios between geometrical quantities, a step which the Greeks never took. Another important contribution Thabit made to geometry was his generalization of the Pythagorean theorem, which he extended from special right triangles to all triangles in general, along with a general proof. [Aydin Sayili (1960). "Thabit ibn Qurra's Generalization of the Pythagorean Theorem", "Isis" 51 (1), p. 35-37.]

In physics, Thabit rejected the Peripatetic and Aristotelian notions of a "natural place" for each element. He instead proposed a theory of motion in which both the upward and downward motions are caused by weight, and that the order of the universe is a result of two competing attractions ("jadhb"): one of these being "between the and celestial elements", and the other being "between all parts of each element separately". [Mohammed Abattouy (2001). "Greek Mechanics in Arabic Context: Thabit ibn Qurra, al-Isfizarı and the Arabic Traditions of Aristotelian and Euclidean Mechanics", "Science in Context" 14, p. 205-206. Cambridge University Press.]

ee also

*Thabit number
*List of Arab scientists and scholars
*Islamic mathematics

Notes

References

*
* Reviews: Seyyed Hossein Nasr (1998) in "Isis" 89 (1) pp. [http://links.jstor.org/sici?sici=0021-1753%28199803%2989%3A1%3C112%3AFR%3E2.0.CO%3B2-C 112-113] ; Charles Burnett (1998) in "Bulletin of the School of Oriental and African Studies, University of London" 61 (2) p. [http://links.jstor.org/sici?sici=0041-977X%281998%2961%3A2%3C406%3ALMIDIA%3E2.0.CO%3B2-K 406] .
*Churton, Tobias. "The Golden Builders: Alchemists, Rosicrucians, and the First Freemasons". Barnes and Noble Publishing, 2006.

External links

* [http://www.renaissanceastrology.com/thabit.html Thabit ibn Qurra on Astrology & Magic]