Ali Qushji, the famous Iranian theologian, astronomer and mathematician
Compiled By: Syed Ali Shahbaz
On December 16, 1474 AD, the theologian, astronomer and mathematician, Ala od-Din Ali Ibn Mohammed, known as Ali Qushji or Qushju-Zadeh (Son of Falconer), passed away in Istanbul at the age of 71.
Born in Samarqand, he was of Iranian origin and played a prominent intellectual role in the court of the astronomer-king Ulugh Beg, after studying under such famous scientists as Qazi-Zadeh Roumi, Ghiyas od-Din Jamshid Kashani and Moin od-Din Kashi. He rejected Aristotelian physics and separated natural philosophy from astronomy, allowing it to become a purely empirical and mathematical science.
Long before Copernicus, he provided evidence of the Earth\'s rotation in his treatise, titled: \"Concerning the Supposed Dependence of Astronomy upon Philosophy\". He contributed to Ulugh Beg\'s famous work \"Zijj-e-Sultani\" and authored several scientific books. He moved to Kerman in southern Iran where he conducted researches on the storms in the Gulf of Oman.
In Kerman he completed the book \"Hall-e Ishkal-e Qamar\" (Explanations of the Periods of the Moon) and also \"Sharh-e Tajrid\", which is an explanation of the famous Iranian theologian-scientist, Khwaja Naseer od-Din Tousi\'s \"Tajrid al-Kalaam\". It is considered one of the important works on physics, optics, metaphysics, and mathematics. He moved to Herat in Khorasan and taught the Persian poet, Mullah Jami, about astronomy.
After a while, he went back to Samarqand, where he worked in the observatory, until Ulugh Beg was assassinated. Ali Qushji then went to the northwestern Iranian city of Tabriz, where around 1470 the Aq Qoyunlu ruler, Uzun Hassan, sent him as a delegate to the court of the Ottoman Sultan, Mohammad II, for whom he wrote in Persian the treatise on astronomy titled \"Risalah dar Hayy’at\".