The end of Aristotelian Astronomy

http://www.noao.edu/outreach/aop/observers/jupmoon.html

Hey guys, after reading tonight's assignment about Newton and looking back on the previous' night assignment about Copernicus, Brahe, Kepler and Galileo, I wanted to know if anyone had an opinion as to who definitively put an end to, or "demolished" the Ptolemaic or geocentric system. I think that the book portrays Newton's ideas as those that put an end to the old astronomic physics, specifically it reads, "The new findings had not, however, been fused together in a new synthesis, a single explanatory system that would comprehend motion both on earth and in the skies. That synthesis, which prevailed until the twentieth century, was the work of Isaac Newton" (594). The book is saying that Newton unified Galileo's discovery of Jupiter's moons, his law of inertia, Copernicus' heliocentric theory, and Kepler's three laws of planetary motion into one big concept that finally "disproved" Aristotelian physics. Newton apparently achieved this success by proving the notion of 'gravity' which strongly supported the heliocentric theory by making it all possible, and much more realistic than a crystal sphere-supported geocentric system.

However, I believe that the Ptolemaic/Aristotelian system was damaged beyond repair much earlier, when Galileo made his discoveries about Jupiter's moons and momentum public. Together, his ideas strongly denied the existence of a crystal sphere system around earth. I think that the discovery of Jupiter's moons could have almost been sufficient in destroying the old theory, because it would have been impossible for the 'crystal sphere' idea to remain credible or impenetrable. The text says, "He quickly discovered the first four moons of Jupiter, which clearly suggested that Jupiter could not possibly be embedded in any impenetrable crystal sphere." (593). Subsequently, Galileo then throws in yet another piece of evidence, his law of intertia. Galileo proves mathematically, and this is important because by proving this mathematically he no longer requires the law of gravity to support his idea, that an object will keep in motion forever unless stopped by something. The text reads, "Rest was not a natural state of objects. Rather, an object continues in motion forever unless stopped by an external force" (593). In a larger picture, Galileo shows the world that planets do not need the assistance of 'angels' or 'crystal spheres' to keep in motion. So in one move, Galileo abolishes the impenetrability and notion of crystal spheres by sighting Jupiter's moons, and then in another body of evidence he further damages the crystal spheres, and the cornerstone of Aristotelian philosophy, by removing their function.

I think that Galileo definitely demolished the crystal sphere aspect of Aristotelian philosophy, and because this idea was so important to old Astronomy, I think that Galileo put an end to the old theory and catalyzed modern astronomy. Without crystal spheres, then the Aristotelian system is not possible, and this opened doors for new theories to take precedence. What idea or figure do you guys think demolished the old theories? Or perhaps, it was not just one person, but a chain of events that, together, put an end to them. Do you think that Galileo's ideas were not strong enough to debunk any theories until reinforced by the revelations of Newton? Or maybe it was even before Galileo, that the geocentric theory was ended.