1100-1160

Arab mathematician and astronomer whose Islah al-majisti (Correction of the Almagest) proved to be a strong influence on scholars throughout the Mediterranean and Europe. A native of Seville, Aflah knew Moses ben Maimon (Maimonides, 1135-1204). He developed a theorem in spherical trigonometry that bears his name, and created an instrument called the torquentum for making transformations between spherical coordinates. His critique of Ptolemy's (c. 100-170) Almagest exerted an impact on a number of thinkers, among them Ibn Rushd (Averroës, 1126-1198).