(ow, Gero, two seconds too late =P)

*raise hand* "The work of Galileo is considered to be a significant break from that of Aristotle and the curch which used Aristotlelian beliefs as main base of knowledge. Galileo proved lost of Aristotelian theories wrong in lots of things. For example, he was a follower of Copernicus' theory that the Sun was the centre of the galaxy and we, the earth, round it up and not the other way round. This theory is called heliocentrism. Since Galileo defied Aristotle's thinking he was therefore defing the curch (even though he was a catholic). In addition, his conflict with the Roman Catholic Church is taken as a major early example of the conflict of religion and freedom of thought, particularly with science, in Western society.

Anyway, to name a few things Galileo preved Aristotle wrong and which caused his impopularity with society and the curch: One of the most famous stories about Galileo is that he dropped balls of different masses from the Leaning Tower of Pisa to demonstrate that their velocity of descent was independent of their mass (excluding the limited effect of air resistance). This was contrary to what Aristotle had taught: that heavy objects fall faster than lighter ones, in direct proportion to weight. He also concluded that objects retain their velocity unless a force -- often friction -- acts upon them, refuting the accepted Aristotelian hypothesis that objects "naturally" slow down and stop unless a force acts upon them.

"There was the smaller contradictions. Like, when refering to technology as distinct from pure physics, which is not the same distinction as made by Aristotle, who would have considered all Galileo's physics as techne or useful knowledge, as opposed to episteme, or philosophical investigation into the causes of things. Also, Galileo Galilei was the first to report lunar mountains and craters, whose existence he deduced from the patterns of light and shadow on the Moon's surface. He even estimated the mountains' heights from these observations. This led him to the conclusion that the Moon was "rough and uneven, and just like the surface of the Earth itself", and not a perfect sphere as Aristotle had claimed.

"Going back to the heliocentrism theory, the one that caused the most troubles: on January 7, 1610 Galileo discovered Jupiter's four largest satellites (moons): Io, Europa, Ganymede, and Callisto. The demonstration that a planet had smaller planets orbiting it was problematic for the orderly, comprehensive picture of the geocentric model of the universe, in which everything circled around the Earth. Besides, Galileo noted that Venus exhibited a full set of phases like the Moon. Because the apparent brightness of Venus is nearly constant, Galileo reasoned that Venus could not be circling the Earth at a constant distance."

Nadia sighed.

"Within other instereting facts, Galieo is reputed to have invented the telescope, but that's quite inacurate; he took the idea from other people and put it under his name to sell it and afford his investigations. He did improve the telescope though, making it smaller and easier to carry plus was the first one to use to to watch the sky - before, I think, it was used on boats to gaze to find the shores, if I'm not much mistaken.

She smiled shippishly. "That's pretty much it. The fact that the church used Aristotlelian books as source of knowledge - something they did a lot at that time, quoting eldery wise man -, made that the new ideas looked against the church when in fact that was not it. The helicentrism theory was the one who suffered the most. We must remember that at that time it was believed that the centre of the universe should be the earth because then it would be proving that God is always watching us. Galileo was asked to take back what he said, and he did to avoid being hanged... and it is said that his last words, when about to die, were "and yet it moves"."