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Copernicus used the same circular-orbit-plus-epicycles system as Ptolemy, just the orbits were centered around the sun (kind of---each planet had its own circle
by canjobear 2y ago
Copernicus used the same circular-orbit-plus-epicycles system as Ptolemy, just the orbits were centered around the sun (kind of---each planet had its own circle, with the sun only approximately in the middle). The system actually had more epicycles than Ptolemy's and was less accurate. It wasn't an advance in any meaningful sense.
The real breakthrough was Kepler, who dropped the idea that planets moved in circles. It was indeed partly a mathematical breakthrough and the reason Kepler's work took a while to catch on is that people couldn't understand his math at first. But it was also empirical, as Kepler had access to new and much more precise observational data collected by his mentor Tycho Brahe.
- btilly 2y agoI'd say that Galileo spotting the phases of Venus was also a big deal.
- rcxdude 2y agoThat only ruled out one particularly broken model (everything revolving directly around the earth). The dominant model at the time had the sun and moon revolving around the earth and everything else revolving around the sun, with epicycles. All the information Galileo was able to present to people was equally consistent with heliocentrism and geocentrism, and Galileo's favored heliocentric model was less elegant and explained no extra data. (Not entirely for lack of trying, though Galileo's favored rhetorical approach was 'I'm obviously right and you're all idiots', he did work with some others to try to demonstrate the rotation of the earth via displacement of dropped objects, but didn't succeed because it's quite a tricky measurement)
- moomin 2y agoIIRC what this comes down to is Copernicus had no desire to tangle with the church. I remember reading he has some footnotes that go “Hey, obviously it works in epicycles but the maths works really well with ellipses and heliocentrism.”