Galileo’s main accomplishments was that he was able to disprove Aristotle’s worldview by using observations through the telescope to deduce certain facts. To begin with, the telescope allowed Galileo to observe that the moon was not completely flat, in fact, it appeared to have mountains on it. This countered the classic Aristotelian view because if the moon was made of “ether,” it could not have a rocky surface like the Earth. Moreover, this observation provided evidence that if a large rocky Moon could move in a continuous orbit (which it does), then so could a large rocky Earth. This disproved Aristotle’s view for why the Earth was stationary. Next, Galileo observed “sunspots,” or darker …show more content…
One observation that definitely disproved the Ptolemaic model was that Venus has phases, much like our Moon does. To the naked eye, Venus always appears as a bright dot in the sky. With a telescope, however, it is fairly easy to see the phases of Venus. Just as the Moon has phases, Venus too has phases based on the planet’s position relative to us and the Sun. Since there was no way for the the Ptolemaic (Earth centered) model to account for these phases, the only possibility must be that Venus is circling the sun (rather than the Earth.) Galileo further disproved the Ptolemaic system by proving that the universe must be