Abu Ja'far al-Khazin

Abu Jafar Muhammad ibn Husayn Khazin (Persian: ابوجعفر خازن خراسانی; 900–971), also called Al-Khazin, was an Iranian^[1] Muslim astronomer and mathematician from Khorasan. He worked on both astronomy and number theory.

Al-Khazin was one of the scientists brought to the court in Ray, Iran by the ruler of the Buyid dynasty, Adhad ad-Dowleh, who ruled from 949 to 983. In 959/960, Khazin was required by the vizier of Ray, who was appointed by ad-Dowleh, to measure the obliquity of the ecliptic.

One of Al-Khazin's works Zij al-Safa'ih ("Tables of the Disks of the Astrolabe") was described by his successors as the best work in the field and they make many references to it.^[2] The work describes some astronomical instruments, in particular an astrolabe fitted with plates inscribed with tables, and a commentary on the use of these. A copy of this instrument was made, but it vanished in Germany during World War II. A photograph of this copy was taken and examined by the historian David King in 1980.^[3]

Al-Khazin also wrote a commentary on the Roman polymath Ptolemy's Almagest in which he gives 19 propositions relating to statements by Ptolemy, and proposed a different model of the cosmos.^[4]

• Dold-Samplonius, Yvonne (1981). "Al-Khāzin, Abū Ja'far Muḥammad Ibn Al-Ḥasan Al-Khurāsānī". In Gillispie, Charles Coulston; Holmes, Frederic Lawrence (eds.). Dictionary of Scientific Biography. Vol. 7 & 8. New York: Scribner. OCLC 755137603.
• King, David A. (2007). "New Light on the Zīij al‐Safāa'ih of Abū Jacfar al‐Khāzin". Centaurus. 23 (2): 105–117. ISSN 0008-8994 – via Researchgate.
• Selin, Helaine (1997). Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures. Berlin; New York: Springer Nature. ISBN 978-1-4020-4960-6.

• Calvo, Emilia (2007). "Khāzin: Abū Jaʿfar Muḥammad ibn al‐Ḥusayn al‐Khāzin al‐Khurāsānī". In Thomas Hockey (ed.). The Biographical Encyclopedia of Astronomers. New York: Springer. pp. 628–9. ISBN 978-0-387-31022-0. (PDF version)
• Pingree, David (1983). "Abū Jaʿfar Ḵāzen". Encyclopædia Iranica.
• Rashed, Roshdi (1996). Les Mathématiques Infinitésimales du IXe au XIe Siècle 1: Fondateurs et commentateurs: Banū Mūsā, Ibn Qurra, Ibn Sīnān, al-Khāzin, al-Qūhī, Ibn al-Samḥ, Ibn Hūd. London: Islamic Heritage Foundation. pp. 737–778, 779–833 (Texte et Traduction: Abū Ja‘far al-Khāzin, Transcrit du commentaire du premier livre de l’Almageste Min al-sharḥ li-al-maqāla al-ülā min al-Majisṭī). ISBN 1-873992-18-1.