English IV Honors
31 August 2012
School of Astronomy founded at Baghdad
The Year 813 (DCCCXIII) was a common year starting on Saturday of the Julian calendar. Al Mamon founded a school of astronomy in Baghdad and translates Ptolemy’s works. Astronomical knowledge from around the world was collected and translated. 'Abdallah al-Ma'mun. Born in Baghdad in 786, died near Tarsus in 833. The seventh and greatest 'Abbasid caliph (813-833). His mother and wife were Persians, which explains his Persian and 'Alid proclivities. He was an ardent Mu'tazil, tried to enforce his views by means of violence. He wrote four long letters to explain the Qur'an was created, and he cruelly punished those who dared entertain different views. He then combined in a remarkable way free thought and intolerance. While persecuting those who objected to Mu'tazilism, Jews and Christians were very welcome at his court. He took considerable pains to obtain Greek manuscripts and even sent a mission to the Byzantine Emperor Leon the Armenian (8l3 to 890) for that purpose. He ordered the translation of these manuscripts. He organized at Baghdad a sort of scientific academy called the House of Wisdom (Bayt al-hilkma), which included a library and an observatory. This was the most ambitious undertaking of its kind since the foundation of the Alexandrian Museum (q. v. first half of third century B. C.). He built another observatory on the plain of Tadmor (Palmyra). The inclination of the ecliptic was found by his astronomers to equal 23o 33' and tables of the planetary motions were constructed. He ordered two degree-measurements to be made to determine the size of the earth one of them near Tadmor (a degree = 6,500 miles) hence circumference of the earth = 20,400 miles; diameter=6,500 miles). A large map of the world was drawn for him. He encouraged philosophers, philologists, traditionalists, and other jurists mathematicians, physicians, astrologers and...