Zij-i Ilkhani
Zīj-i Īlkhānī (
Arabic
.
The book contains tables for calculating the positions of the planets and the names of the stars. It included data derived from the observations made over the course of 12 years in the Maragha observatory, completed in 1272. The planetary positions of the Zij-i Ilkhani, derived from the zijs of Ibn al-A'lam and Ibn Yunus (10/11th cent. AD), were so at fault that later astronomers, such as al-Wabkanawi and Rukn al-Din al-Amuli, criticized it severely.
The Zīj-i Īlkhānī set the
arcseconds per year, which is very close to the modern value of 50.2 arcseconds.[1] The book also describes a method of interpolation
between the observed positions, which in modern terms may be described as a second-order interpolation scheme.
History
Hulagu Khan believed that many of his military successes were due to the advice of astronomers (who were also
Mu'ayyid al-Din al-'Urdi from Damascus. Furthermore, the influence of Chinese astronomy was brought by Fao Munji, whose astronomical experience brought improvements to Ptolemaic system used by al-Tusi; traces of the Chinese system may be seen in Zij-i Ilkhani. The tables were published during the reign of Abaqa Khan
, Hulagu's son, and named after the patron of the observatory. They were popular until the 15th century.
Some Islamic astronomical tables such as the Zij-i Al-`Ala'i of Abd-Al-Karim al-Fahhad and the Zij al-Sanjari of
Byzantine Greek by Gregory Chioniades and studied in the Byzantine Empire. Chioniades himself had studied under Shams ad-Din al-Bukhari, who had worked at the famous Maragheh observatory after the death of al-Tusi.[2]
See also
- Zij
- Astronomy in medieval Islam
Notes
- Bibcode:1939PA.....47..233R [1]
- ^ Joseph Leichter (June 27, 2009). "The Zij as-Sanjari of Gregory Chioniades". Internet Archive. Retrieved 2009-10-02.
References
- Nasir al-Din al-Tusi (1272) Zij-i Ilkhani, British Museum, MS Or.7464.
- J. A. Boyle (1963) "The Longer Introduction to the Zij-i Ilkhani of Nasir ad-Din Tusi", Journal of Semitic Studies 8(2), pp.244-254
- Transactions of the American Philosophical Society46(2), pp. 3, 39-40.
- Javad H. Zadeh (1985) "A Second Order Interpolation Scheme Described in the Zij-i Ilkhani", Historia Mathematica 12: 56–59.
External links
- The Zij-i Ilkhani held by the Wellcome Collection in London