Al-Birjandi

Abdal Ali ibn Muhammad ibn Husayn Birjandi () (died 1528) was a 16th-century Persian astronomer, mathematician and physicist who lived in Birjand.

==Astronomy== Al-Birjandi was a pupil for Mansur ibn Muin al-Din al-Kashi, a member at the Samarkand Observatory, otherwise known as The Ulugh Beg Observatory. In discussing the structure of the cosmos, al-Birjandi continued Ali al-Qushji's debate on the Earth's rotation. In his analysis of what might occur if the Earth were moving, he develops a hypothesis similar to Galileo Galilei's notion of "circular inertia", which he described in the following observational test (as a response to one of Qutb al-Din al-Shirazi's arguments):