Footnote 65:

It is not clear whether this appeal to the subject of Copernicus’ De revolutionibus orbium coelestium and the linkage, in the sentence which follows, of microcosm and macrocosm, reflects any actual interest on the Emperor’s part in these subjects. Like Vesalius’ own work, Copernicus’ challenged the authority of a 2nd century AD scientist, Claudius Ptolemy. Also like Vesalius, Copernicus was a working physician who had studied medicine at Padua. Though not published in its final form until the year of his death, Copernicus’ research had probably been completed by 1530, and his heliocentric theory had been in circulation as early as 1514, the year of Vesalius’ birth.