3) People were willing to accept Galileo's model as a good predictive model however his proof was very flawed. What made his situation worse was that he insisted his theory was correct despite the fact that the lack of stellar parallax proved his theory false. (Stellar parallax was proved in the 19th century)
The heliocentric model was first proposed by Copernicus, not Galileo. While Galileo supported the heliocentric system and while it was at the center of the trial, it was negligible compared to his other achievements. Most people don't understand what Galileo actually did.
Galileo formalized the Scientific Method. This is the cycle of Observe-Model-Predict-Test, where the test becomes new observation. The SM is a self-improving, self-correcting process that has generated all of modern day technology. Computers, TV, Cars, Airplanes, ALL of Medicine, even modern day industrial societies are largely based upon the Scientific Method.
The method can look simple, but was a huge contrast to the way things were done before: "I think this is how things work and I can interpret this ancient book to agree with me, therefore, what I have is ABSOLUTE TRUTH and nobody should question it." Examples of this flawed thinking can be found in interpretation of Aristotle's work, while I can hardly point fingers at Aristotle for saying that the flies have 4 legs (nobody's perfect), I definitely hold it against everyone else who NEVER BOTHERED TO CHECK! This is the main flaw of pre-Galilean thinking.
Galileo's may have had poor evidence in support of the heliocentric system, however, his observation of the moons of Jupiter should have been sufficient to reject the geocentric one (again people never event tried to check). In the same note, I don't think anyone at the time actually tried to measure the stellar parallax and use that as evidence against heliocentrism. We are talking about the time when the spyglass was a major invention, there were no real telescopes and sextant wasn't even invented yet.
Another example of Galileo's challenge to the preconceived flawed concepts was the evidence against the concept that bodies fall with speed proportional to their weight. He did not have the concept of Gravity much less aerodynamics, however, he had direct evidence disproving thousand year old concepts.
Other than the Scientific Method, Galileo's second major contribution is the challenge of Aristotle's "static theory" and establishing what is now knows as Galilean Relativity (not to be confused with Einstein's Special or General Relativity). Galilean Relativity is summarized in Newton's first law of Mechanics.
"Static Theory": every body's natural state is that of rest. A body moves when a force is applied to it and without the force, the body will eventually stop. Also, the speed of the body is proportional to the force applied. (This may sound right, but it is not. Aristotle observed what we now call friction and he extrapolated too much. Yet again, nobody tied to rigorously check.)
Galilean Relativity (i.e. Newton's First Law): a body remain at rest OR keeps moving in a straight line until it interacts with another body. While Galileo tried to measure the relation between speed and force, he only got so fat as to find that the distance a body falls is proportional to the square of the time (Galileo actually measured that). It takes Calculus to get from this to Newton's Second Law (commonly know as F = ma). I also don't think Galileo had the concept of mass either.
Note that going from Galilean Relativity and F = ma, using Copernicus's measurement for the ratio of period of rotation to distance from the sun for the planets, you can get the inverse-square law of Gravity with two steps of elementary algebra. But this is now on a tangent.
Putting someone under house arrest for having a strange idea is wrong even if the idea is completely absurd, much less not fully supported. Galileo's ideas were not fully supported by evidence, but neither were the ideas of Isac Newton and Albert Einstein. For example: the exact orbit of Mercury doesn't match Newton's Law of Gravity, not to mention that he got the formula for Kinetic Energy totally messed up. Einstein, at the end of his career refused to accept quantum mechanics and the strong nuclear force, despite the evidence and measurements (Einstein kept working on his unification theory, which directly contradicts evidence). Should we have put Newton and Einstein under house arrest too? If we were to treat scientists that way, we would still be using bloodletting to cure the flu.
Science is never perfect, however, it is always self-improving and self-correcting. Heliocentric system is wrong, Geocentric system is wrong and Flat-Earth system is considered as major example of ignorance, however, all three of those are good predictive models under many circumstances. The people (ALL people, not just the Church, but also the "philosophers" at the time) should have first of all accepted that the Geocentric system fails. Then they should have funded further research in taking accurate measurements of stellar parallax and other related phenomena and/or looked at an explanation for the lack of stellar parallax and/or considered an alternative
falsifiable theory (I guess hypothesis is more appropriate name here).
Galileo's trial wasn't solely Church's doing, however, the Church is as guilty as it can be.
I should get out of the University more often.
