“but he was motivated by the desire to establish uniform circular motion”

Will Crawley has a good post [and links] on the apparent identification of the remains of Nicolaus Copernicus in Poland – assuming that the hair found in a book once owned by the astronomer was his. But there’s an interesting caveat to the story in this Cambridge University hosted Copernicus biography. Btw, Heidemarie Stefanshyn Piper says ‘thanks’. Galileo Galilei, maybe not so much.

Copernicus is often portrayed as a revolutionary figure who advocated a heliocentric system, overthrowing existing systems and institutions. Yet, his monumental work, the De Revolutionibus, is far from a revolutionary manifesto for modern astronomy. Copernicus is known to have carried out many observations (though he explicitly mentions only about 27), and none seems to have been crucial for formulating his theory. The work follows closely the structure of Ptolemy’s Almagest, it is based on parameters and data from Ptolemy, and his dedication to the Pope is written in a fashionable style. He does indeed provide a model of the universe in which the earth and all the other planets orbit around the sun and the earth acquired a daily rotation, but the sun itself was not quite in the center of that universe. He established the order of planets and devised a system which accounted for the movements of planets without equants, but he was motivated by the desire to establish uniform circular motion, itself a classical ideal. Copernicus certainly believed that this was the true system of the physical universe, but this conviction was not shared widely by his contemporaries for various reasons.