Alfonso X of CastileBorn 23 Nov 1221; died 4 Apr 1284 at age 62. Spanish monarch and astronomer who encouraged the preparation of revised planetary tables (1252), published on the day of his accession to the throne as king of Castile and León. These “Alfonsine Tables”a revision and improvement of the Ptolemaic tables, were the best available during the Middle Ages; they were not replaced by better ones for over three centuries. The astronomical data tabulating the positions and movements of the planets was compiled by about 50 astronomers he had assembled for this purpose. He questioned the complexity of the Ptolemaic model centuries before Copernicus. “If the Lord Almighty had consulted me before embarking on the Creation, I would have recommended something simpler.”He also wrote a commentary on alchemy. |