Christián C. Carman, CONICET-UNQ

"The Coincidence of the Results of Ptolemy’s Earth-Sun Distance Calculations:

Intentional or by Chance?”

In this talk, I analyze the coincidence of the results in the calculation of the Earth-Sun distance carried out by Ptolemy both in his Almagest and, with another method, in his Planetary Hypotheses. The values obtained for the Earth-Sun distance in both works are very similar to each other. Due to this fact, the great majority of historians have suspected that Ptolemy had altered or at least had selected the data in order to obtain this coincidence. I will provide a reconstruction of a way in which Ptolemy could have altered or selected the data and subsequently I will try to argue in favor of its historical plausibility.