Mu'ayyad al-Din al-'Urdi

Mu’ayyad al-Din al-’Urdi (died 1266) was an Kurdish Muslim astronomer, mathematician, architect and engineer working at the Maragheh observatory. He was born in Aleppo,todays Syria, and later moved to Maragheh, Azarbaijan, Kurdistan, to work at the Maragha observatory under the guidance of Nasir al-Din Tusi.^[1]

He is known for being the first of the Maragha astronomers to develop a non-Ptolemaic model of planetary motion.^[2] In particular, the Urdi lemma he developed was later used in the geocentric model of Ibn al-Shatir in the 14th century and in the heliocentric Copernican model of Nicolaus Copernicus in the 16th century.

As an architect and engineer, he was responsible for constructing the water supply installations of Damascus, Syria, in his time.^[3]

See also

• Zij-i Ilkhani

Notes

1. ^ Saliba (1979), p. 576.
2. ^ Saliba (1979).
3. ^ Al-Urdi's Article on 'The Quality of Observation', FSTC Limited

References

• George Saliba (1979). "The First Non-Ptolemaic Astronomy at the Maraghah School", Isis 70 (4), p. 571-576.
• George Saliba (1990). The Astronomical Work of Mu'ayyad al-Din al-'Urdi (d. 1266): A Thirteenth Century Reform of Ptolemaic Astronomy, Markaz dirasat al-Wahda al-'Arabiya, Beirut.

External links

• Islamic astronomy

Persondata
Name	Urdi
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Date of birth
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Date of death	1266
Place of death