Al-Kharaqī

Abū Muḥammad 'Abd al-Jabbār al-Kharaqī, Persian: بهاءالدین ابوبکر محمد بن احمد بن ابوبشر also Al-Kharaqī (1084-1158[1]) was a Persian[2] astronomer and mathematician of the 12th century, born in Kharaq near Merv.

[3] He was in the service of Sultan Sanjar at the Persian Court.

Al-Kharaqī challenged the astronomical theory of Ptolemy in the Almagest, and established an alternative theory of the spheres, imagining huge material spheres in which the planets moved inside tubes.

[3] He later wrote at-Tabṣıra fî ʿilmi’l-hayʾa as a second edition to his well-known book Muntahā al-idrāk fī taqāsīm al-aflāk in which he removed some parts and reshaped its structure as two parts instead of three.

[1] During his travels to the Ottoman Empire in 1536, Guillaume Postel acquired an astronomical work by al-Kharaqī, Muntahā al-idrāk fī taqāsīm al-aflāk ("The Ultimate Grassp of the Divisions of Spheres"), annotated it, and brought it back to Europe.