Farghani
Abu l-Abbas Ahmad ibn Muhammad ibn Kathir al-Farghani ( Arabic أبو العباس أحمد بن محمد بن كثير الفرغاني, DMG Abu l-ʿAbbās Aḥmad ibn Muḥammad ibn Kaṯīr al-Farġānī ) Al-Farghani is an Islamic - Central Asian astronomer of the 8th – 9th centuries. Century. The exact date of his birth is not known. Historians put the year around 798. The scholar's full name is Abul-Abbas Ahmad ibn Muhammad ibn Katir al-Farghani.
He came from the Ferghana Valley in Central Asia , probably from the city of Quva , but lived mainly in Baghdad at the court of the caliph al-Ma'mun . In Islamic culture he was honored with the name Hosib (mathematician) and Munajim ar-Rais (chief astronomer). In Europe he was known as Alfraganus . He was an astronomer and engineer at the Caliph's court in Baghdad and later in Egypt, where he directed work on the Roda Nilometer .
In the " House of Wisdom " academy in Al-Ma'mun (Baghdad), he made a major contribution to astronomy, mathematics and geography. Among his major works are "The Book of Astronomical Movements and Brief Explanation of the Science of the Stars", "Thirty Elements", "Theoretical Calculations on the Sphere", "Treatise on Time when the Moon is Above and Below the Earth". In addition, Al-Farghani wrote explanations for Ptolemy's work "Almagest" .
As one of the first scholars, Al-Farghani proved the spherical structure of the earth, determined the diameter of the earth and the distance between the planets. He characterized June 22nd as 'the longest day' of the year and December 23rd as 'the shortest day' of the year. Al-Farghani's works have been used as teaching aids in Europe for several centuries.
Farghani calculated the circumference of the earth on behalf of his caliph. In order to determine 2 ° of the circumference of the earth, he had the caliph's servants measure 224 km of desert by hand. He was able to calculate the circumference of the earth with 99% accuracy.
To this day, his works are of great importance. His invention of the “ Nilometer ” (in Cairo) is still used today.
The lunar crater Alfraganus was also named after him.
Web links
- Literature by and about Aḥmad Ibn-Muḥammad al-Farġānī in the catalog of the German National Library
- Muhammedis Fil.Ketiri Ferganensis, qui vulgo Alfraganus dicitur, Elementa Astronomica: arabice & latine cum notis ad res exoticas sive orientales, quae in iis occurrunt. Opera at e-rara
| personal data | |
|---|---|
| SURNAME | Farghani |
| ALTERNATIVE NAMES | Abu l-Abbas Ahmad ibn Muhammad ibn Kathir al-Farghani (full name); Alfraganus (Latinized) |
| BRIEF DESCRIPTION | arab astronomer |
| DATE OF BIRTH | 8th century or 9th century |
| DATE OF DEATH | after 861 |