One thing often elided in this general discussion is the fact that Copernicus's heliocentric model was still wrong, because he was still using circular orbits with uniform speed. It was less wrong in an absolute sense, but from a practical standpoint of predicting the planets' motions from the surface of the Earth it didn't really do substantially better than the Ptolomaic model (it actually required more epicycles, which were still unexplained in either theory). Worse, a heliocentric model would (from basic geometry) require the distant fixed stars to undergo parallax (a shift in their apparent positions) over the course of the year, which wasn't measurable with the equipment of the time*. So it was less a case of "this new model is clearly correct but we're not going to go with it for ideological reasons", it was more like "this new model is not obviously any better than the current consensus model (and is geometrically disproven), so there's no compelling reason to switch". It would take another half-century until Kepler discarded circles and used a heliocentric model with elliptical orbits for it to be demonstrably better than a geocentric model at predicting the planets' motions.
(Though now I'm curious how well a geocentric model with elliptical orbits would fit.)
*And wouldn't be until 1838.
(Though now I'm curious how well a geocentric model with elliptical orbits would fit.)
*And wouldn't be until 1838.
Statistics: Posted by Philadelphus — 15 Apr 2025 05:45
