We come to the last episode before the blow fell. Galileo had repeatedly hinted that he had discovered a decisive physical proof of the Copernican theory, but had so far refused to disclose it. When he began to feel that arguing about the miracle of Joshua and the ludicrousness of Ptolemy was no longer of avail, and that his position was becoming impossible, he produced, as a last card, his ‘conclusive physical proof’. It was his theory of the tides.
