Abu Mahmud al-Khujandi
Abu Mahmud Hamid ibn al-Chidr al-Khujandi ( Arabic أبو محمود حميد بن الخضر الخجندي, DMG Abū Maḥmūd Ḥamīd bin al-Ḫiḍr al-Ḫuǧandī , also Abu-Mahmud al-Khujandi ; * around 940 in Khujand (today Tajikistan ); † around 1000), also Chodschandi , was a Persian astronomer and mathematician.
The construction of the observatory near the city of Rey (Persia) goes back to him . The few facts about him come from the surviving writings and commentaries of Nasir ad-Din at-Tusi . According to them, he was one of the rulers of the Mongol tribes in the Khudzhand region.
As an astronomer he worked under the auspices of the Buyid Amir von Rey. In 994 he built the astronomical wall sextant (comparable to a quadrant ). With this he determined the inclination of the ecliptic to be 23 ° 32'19 ". Due to the gravitational influences of the other planets, this astronomical base variable changes over time and has to be measured again regularly. In the 2nd century it was 23 ° 51'20", today's measurements show 23 ° 26 '.
As a mathematician, he presented a proof of Fermat's great theorem for the case n = 3, which, however, as criticized by Abu Ja'far al-Khazin , turned out to be false. He also discovered the law of sines , although it is uncertain whether Abu Nasr Mansur or Abu l-Wafa discovered it earlier.
Web links
- John J. O'Connor, Edmund F. Robertson : Abu Mahmud Hamid ibn al-Khidr Al-Khujandi. In: MacTutor History of Mathematics archive .
| personal data | |
|---|---|
| SURNAME | Khujandi, Abu Mahmud al- |
| ALTERNATIVE NAMES | Khujandi, Abu Mahmud Hamid ibn al-Chidr al- (full name); Khujandi, Abu-Mahmud al-; أبو محمود حميد بن الخضر الخجندي (Arabic) |
| BRIEF DESCRIPTION | Persian astronomer and mathematician |
| DATE OF BIRTH | around 940 |
| PLACE OF BIRTH | Khujand (now Tajikistan ) |
| DATE OF DEATH | around 1000 |