The trouble with Eudoxus (Q2752081)

This note belongs to the recent serious studies [see \textit{H. Mendell}, Centaurus 40, 177--275 (1998); \textit{I. Yavetz}, Arch. Hist. Exact Sci. 52, No. 3, 221--278 (1998; Zbl 0895.01003)] reexamining Eudoxus' theory of homocentric spheres, which has been thought to be explained well enough by Schiaparelli in the nineteenth century. NEWLINENEWLINENEWLINEIt examines very meticulously the extant sources about the theory of homocentric spheres of Eudoxus and Callippus (mainly Aristotle's \textit{Metaphysica} and Simplicius' commentary to \textit{De Caelo}), giving translation with extensive commentaries. NEWLINENEWLINENEWLINEAs a result of careful examination, Simplicius' commentary is credited with by far more exact description of Eudoxean theory than used to be believed. At the same time, the following interpretations predominant until now, are judged to be impossible to deduce from the extant documents: it was the retrograde motion of planets that induced Eudoxus to construct his theory; the theory was rejected because of the unsatisfactoriness of this model for retrograde motion, and the failure to explain the variation of apparent size (brightness) of planets. The author proposes, as more probable alternative to Eudoxus' motivation, differences in the time from last appearence in the evening to the first appearence in the dawn.NEWLINENEWLINEFor the entire collection see [Zbl 0964.00010].