Ibn al-Shatir (or Ibn ash-Shatir) (1304–1375) was a Muslim astronomer of Damascus. He worked as timekeeper in the Umayyad Mosque there, and constructed a magnificent sundial for its minaret in 1371/72. His work kitab nihayat as-sul fi tashih al-usul ("A Final Inquiry Concerning the Rectification of Planetary Theory") in treating the motion of the Moon eliminated the need for an equant by introducing an extra epicycle, departing from the Ptolemaic system in a way very similar to Copernicus. A possible influence of the work on Copernicus has been proposed, but is controversial.

References

• Howard R. Turner, "Science in Medieval Islam, an illustrated introduction", University of Texas Press, Austin, 1995. ISBN: 0292781490 (pb) ISBN: 0292781474 (hc)
• Victor Roberts, "The Solar and Lunar Theory of Ibn ash-Shatir: A Pre-Copernican Copernican Model" (1957)

External links

• http://faculty.kfupm.edu.sa/phys/alshukri/PHYS215/Islamic%20astronomy.htm
• http://www.riifs.org/review_articles/review_v1no2_sliba.htm
• http://www.angelfire.com/il/Fernini/ifscience.html
• http://www.cs.sfu.ca/~anoop/weblog/archives/000080.html