Hi
I am writing a book about the role of Ockham’s razor in science and one of the topics is the successive simplification of the solar system from the Ptolemaic system through Copernicus to Kepler.
Both Copernicus and the young Kepler (before he worked out the correct system) and Galileo and Tycho Brahe claimed that the Copernican system was simpler than the Ptolemaic and simplicity was the reason for their preference for heliocentricity. It is well known that the heliocentric Copernican system provided no more accurate predictions than Ptolemy's geocentric system. So despite their lack of evidence, Copernicus, (the young) Kepler and Galileo were all convinced the heliocentric system was true solely on the simplicity criterion – Ockham’s razor. Galileo additionally gave erroneous proofs, such as the tides but, apart from these, the only argument the Copernicus, Kepler and Galileo could muster for heliocentricity was that the Copernican system was simpler than the Ptolemaic.
Yet historians of science such as Thomas Kuhn and Arthur Koestler, who have counted the orbits and epicycles (circles) in both systems and come to roughly the same number, so they claim that Copernicus, Kepler and Galileo were deluded as both systems were equally complex. But then why had these great scientists been convinced by geocentricity without any other evidence? I find it hard to believe that they were deluded themselves.
The reason i believe is that the Copernican system, despite having a similar number of circles, was actually simpler because it only had to correct for Copernicus' two errors: his insistence on perfect circles and uniform motion. The deviations of the actual planetary orbits from perfect circles to ellipses and uniform motion to variable motion is relatively minor compared to the deviation of a geocentric from a heliocentric system. So i am guessing that Copernicus' correcting epicycles are much smaller than Ptolemy's. But all the diagrams i can see online are not drawn to scale so i cannot compare them.
Does anyone have scaled diagrams of the two system? Or is it possible to calculate the relative size of the circles in both systems?