Owen Gingerich - Empirical proof and/or persuasion — lecture on Galileo's observation of the phases of Venus from a renowned historian of science
YouTube animation of the phases of Venus predicted by the pure geocentric Ptolemaic model [1] (页面存档备份,存于互联网档案馆)
YouTube animation of the phases of Venus predicted by the heliocentric model (and implicitly also by the geo-heliocentric models such as the Tychonic) [2] (页面存档备份,存于互联网档案馆)