Nur al-Din ibn Ishaq al-Bitruji (A great astronomer)

Nur al-Din ibn Ishaq al-Bitruji (A great astronomer)  

Bitruji (Nur al-Din ibn Ishaq al-Bitruji) (Nur ad-Din al-Betrugi) (Abu Ishak ibn al-Bitrogi) (Alpetragius) (al-Bidrudschi) (d. 1204). Born in Morocco, he later migrated to Spain and lived in Seville (in Arabic, Isbiliah). He died at the beginning of the thirteenth century around 1204.

Al-Bitruji was a leading astronomer of his time. His Kitab al-Hay’ah was popular in Europe in the thirteenth century. It was first translated into Hebrew and then from Hebrew into Latin. The Latin edition of his book was printed in Vienna in 1531. He attempted to modify Ptolemy’s system of planetary motions, but was unsuccessful primarily because he followed Aristotle’s notion of perfect (circular) motion. However, other Spanish Arab astronomers have suggested an elliptical orbit for planetary motion. Beer and Madler in their famous work Der Mond named a surface feature of the Moon after al-Bitruji (Alpetragius). It is a crater twenty-six miles in diameter. It has a small conical peak at its center and its terraced perpendicular walls and surrounding plain shine with noticeable brightness.

Nur al-Din ibn Ishaq Al-Bitruji and Abu Ishâk ibn al-Bitrogi; another spelling is al Bidrudschi) (known in the West by the Latinized name of Alpetragius) (died ca. 1204 AD) was an Arab astronomer and philosopher of the Islamic Golden Age (Middle Ages). Born in Morocco, he settled in Seville, in Andalusia. He became a disciple of Ibn Tufail (Abubacer) and was a contemporary of Averroës (Ibn Rushd).

Al Bitrugi wrote the Kitab-al-Hay’ah, in which he advanced a theory on planetary motion that avoided both epicycles and eccentrics, and attempted to account for the phenomena peculiar to the wandering stars, by compounding rotations of homocentric spheres. This was a modification of the system of planetary motion proposed by his predecessors, Ibn Bajjah (Avempace) and Ibn Tufail (Abubacer). His efforts were unsuccessful in replacing Ptolemy's planetary model, due to the numerical predictions of the planetary positions in his configuration being less accurate than that of the Ptolemaic model, mainly because he followed Aristotle's notion of perfect circular motion.