1474
Ali Qushji
Astronomer and mathematician
A Samarkand-born astronomer and mathematician, Ulugh Beg's closest disciple and the man who completed the Zij-i Sultani. In later life he helped shape Ottoman science in Istanbul.
© Davide Mauro, CC BY-SA 4.0
The falconer's son
Ala al-Din Ali ibn Muhammad was born in Samarkand around 1403. His nickname Qushji, 'the falconer', came from his father, who kept the hunting birds at Ulugh Beg's court. He studied in Samarkand under Qadi Zada al-Rumi and Jamshid al-Kashi, then furthered his education in Kerman, in Iran, where he wrote a treatise on the phases of the Moon.
Back in Samarkand he presented it to Ulugh Beg, who — so the story goes — read it from beginning to end standing up. Ali Qushji joined the observatory, took charge of the observations after Qadi Zada's death and, with Ulugh Beg, brought the Zij-i Sultani to completion; later he wrote a commentary on it.
From Samarkand to Istanbul
After Ulugh Beg's murder in 1449 he left Samarkand, spending time in Herat and elsewhere before entering the service of the Aq Qoyunlu ruler Uzun Hasan in Tabriz. Uzun Hasan sent him as an envoy to the Ottoman sultan Mehmed II, who kept him at his court. From the early 1470s Ali Qushji taught at the Hagia Sophia madrasa in Istanbul and left a deep mark on the teaching of mathematics and astronomy in Ottoman schools.
His Persian Treatise on Astronomy and his Arabic al-Fathiyya (astronomy) and al-Muhammadiyya (arithmetic) remained textbooks for centuries. In his commentary on Tusi's Tajrid he argued that astronomy should stand independent of Aristotelian natural philosophy, and that philosophical arguments could not rule out the Earth's rotation — a bold step for medieval science.
He died in Istanbul in December 1474 and was buried in the cemetery of the Eyüp mosque.
