Abu Jafar Muhammad ibn Husayn Khazin ( fa, ابوجعفر خازن خراسانی; 900–971), also called Al-Khazin, was an

Iranian Iranian may refer to: * Iran, a sovereign state * Iranian peoples, the speakers of the Iranian languages. The term Iranic peoples is also used for this term to distinguish the pan ethnic term from Iranian, used for the people of Iran * Iranian lan ...

Muslim Muslims ( ar, المسلمون, , ) are people who adhere to Islam, a monotheistic religion belonging to the Abrahamic tradition. They consider the Quran, the foundational religious text of Islam, to be the verbatim word of the God of Abrah ...

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

and

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

from

Khorasan Khorasan may refer to: * Greater Khorasan, a historical region which lies mostly in modern-day northern/northwestern Afghanistan, northeastern Iran, southern Turkmenistan, Tajikistan, and Uzbekistan * Khorasan Province, a pre-2004 province of Ira ...

. He worked on both

astronomy Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...

and

number theory Number theory (or arithmetic or higher arithmetic in older usage) is a branch of pure mathematics devoted primarily to the study of the integers and arithmetic function, integer-valued functions. German mathematician Carl Friedrich Gauss (1777� ...

. Al-Khazin was one of the scientists brought to the court in Ray, Iran by the ruler of the

Buyid dynasty The Buyid dynasty ( fa, آل بویه, Āl-e Būya), also spelled Buwayhid ( ar, البويهية, Al-Buwayhiyyah), was a Shia Iranian dynasty of Daylamite origin, which mainly ruled over Iraq and central and southern Iran from 934 to 1062. Coupl ...

, Adhad ad-Dowleh, who ruled from 949 to 983 AD. In 959/960 Khazin was required by the

Vizier A vizier (; ar, وزير, wazīr; fa, وزیر, vazīr), or wazir, is a high-ranking political advisor or minister in the near east. The Abbasid caliphs gave the title ''wazir'' to a minister formerly called ''katib'' (secretary), who was a ...

of Ray, who was appointed by ad-Dowleh, to measure the obliquity of the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic again ...

. One of Al-Khazin's works ''

Zij A zij ( fa, زيج, zīj) is an Islamic astronomical book that tabulates parameters used for astronomical calculations of the positions of the Sun, Moon, stars, and planets. Etymology The name ''zij'' is derived from the Middle Persian term ' ...

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. The work describes some astronomical instruments, in particular an

astrolabe An astrolabe ( grc, ἀστρολάβος ; ar, ٱلأَسْطُرلاب ; persian, ستاره‌یاب ) is an ancient astronomical instrument that was a handheld model of the universe. Its various functions also make it an elaborate inclin ...

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 Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

at the time of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. A photograph of this copy was taken and examined by D.A. King in 1980. Al-Khazin also wrote a commentary on

Ptolemy Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importanc ...

's ''

Almagest The ''Almagest'' is a 2nd-century Greek-language mathematical and astronomical treatise on the apparent motions of the stars and planetary paths, written by Claudius Ptolemy ( ). One of the most influential scientific texts in history, it canoni ...

'' in which he gives nineteen propositions relating to statements by Ptolemy. He proposed a different solar model from Ptolemy's.

References

Sources

*
PDF version
* * * Reviews: Seyyed Hossein Nasr (1998) in ''Isis'' 89 (1) pp
112-113
Charles Burnett (1998) in ''Bulletin of the School of Oriental and African Studies, University of London'' 61 (2) p
406

External links

* {{DEFAULTSORT:Khazin, Abu Jafar Al 900 births 971 deaths 10th-century Iranian mathematicians 10th-century Iranian astronomers Scholars under the Buyid dynasty