Al-Kharaqī

Note of Guillaume Postel on the Arabic astronomical manuscript of al-Kharaqī, Muntahā al-idrāk fī taqāsīm al-aflāk ("The Ultimate Grasp of the Divisions of Spheres"). Abū Muḥammad 'Abd al-Jabbār al-Kharaqī, also Al-Kharaqī (1084-1158 ) was a Persian astronomer and mathematician of the 12th century, born in Kharaq near Merv. 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.

Al-Kharaqī also wrote mathematical treatises, now lost, Al-Risala al-Shāmila ("Comprehensive Treatise") and Al-Risala al-Maghribiyya ("The North African Treatise", related to the calculus of dirham and dinar).

Works Muntahā al-idrāk fī taqāsīm al-aflāk ("The Ultimate Grassp of the Divisions of Spheres") 1138/9 Al-Risala al-Shāmila ("Comprehensive Treatise") Al-Risala al-Maghribiyya ("The North African Treatise")