Alī ibn ʿĪsā al-Asṭurlābī | |
|---|---|
علي بن عيسى | |
| Born | before 858 |
| Academic work | |
| Era | Islamic Golden Age |
| Main interests | Geography, astronomy |
ʿAlī ibn ʿĪsā al-Asṭurlābī (Arabic: علي بن عيسى, fl. 832) was a 9th century Arab geographer and astronomer. He wrote a treatise on the astrolabe and was an opponent of astrology. During the reign of al-Ma'mun, and together with Khālid ibn ʿAbd al-Malik al-Marwarrūdhī, he participated in an expedition to the Plain of Sinjar to measure the length of a degree.[1] Differing reports state that they obtained a result of 56 miles (90 km), 56 and two-thirds, or 56 and one-quarter miles per degree.[2]