Abū Muḥammad 'Abd al-Jabbār al-Kharaqī, also Al-Kharaqī was a Persian astronomer and mathematician of the 12th century, born in Kharaq near Merv

Merv

Merv , formerly Achaemenid Satrapy of Margiana, and later Alexandria and Antiochia in Margiana , was a major oasis-city in Central Asia, on the historical Silk Road, located near today's Mary in Turkmenistan. Several cities have existed on this site, which is significant for the interchange of...

. He was in the service of Sultan Sanjar at the Persian Court. Al-Kharaqī challenged the astronomical theory of Ptolemy

Ptolemy

Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

 in the Almagest

Almagest

The Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...

, and established an alternative theory of the spheres, imagining huge material spheres in which the planets moved inside tubes.

During his travels to the Ottoman Empire

Ottoman Empire

The Ottoman EmpireIt was usually referred to as the "Ottoman Empire", the "Turkish Empire", the "Ottoman Caliphate" or more commonly "Turkey" by its contemporaries...

 in 1536, Guillaume Postel

Guillaume Postel

Guillaume Postel was a French linguist, astronomer, Cabbalist, diplomat, professor, and religious universalist.Born in the village of Barenton in Basse-Normandie, Postel made his way to Paris to further his education...

 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.

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

Calculus

Calculus is a branch of mathematics focused on limits, functions, derivatives, integrals, and infinite series. This subject constitutes a major part of modern mathematics education. It has two major branches, differential calculus and integral calculus, which are related by the fundamental theorem...

 of dirham

Dirham

Dirham or dirhem is a unit of currency in several Arab or Berber nations, and formerly the related unit of mass in the Ottoman Empire and Persian states...

 and dinar

Dinar

The dinar is the official currency of several countries.The history of the dinar dates to the gold dinar, an early Islamic coin corresponding to the Byzantine denarius auri...

).

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")