Parameters of planetary theory (1)

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The really significant contribution of Babylonian astronomy to Greek astronomy, in particular to Hipparchus’ astronomy, lies in the establishment of very accurate values for the characteristic parameters of lunar and planetary theory and in particular in the careful separation of the components of the lunar motion - longitude, anomaly, latitude, and nodal motion. The value of one of these parameters, the evaluation of the length of the mean synodic month as 29: 31,50.8,20 days is not only fundamental for Hipparchus’ theory of the moon but still appears in the Toledan Tables of the eleventh century. Islamic astronomy of the ninth century received its first impulses from Persia and India and assimilated the Ptolemaic refinements only somewhat later, in particular through al-Battānī, around 900. The earlier phase is mainly represented by al-Khwārizmi and influenced Spanish Islamic astronomy which remained somewhat outside the development in the Near East, Persia and Byzantium. But the European revival of astronomy beginning in the twelfth and thirteenth centuries took place mainly in Spain and Southern France and thus reflects again the Hindu, ultimately Babylonian, component of Islamic astronomy. Not until the full recovery of the Ptolemaic methods in the Renaissance of the fifteenth century did the influences directly traceable to Babylonia of the Seleucid-Parthian period disappear.

Bibliography

Amar Annus

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