Galileo was a great scientist, mathematician and astronomer. He was not believer in myths and stories. He wanted to test the principles and see if could observe them in the real world
He had made the statement that the Earth was round and not flat he also had claimed that the earth is not the center of the universe; the sun is. He had heard of the invention called the telescope and had reinvented it so he look better and farther into space. the Catholic Churches were not happy with this and hd the sent him int housing prison for life where he had then died later on after blindness.
The ball had dropped at the same time because they had both had the same gravity as they had been falling a and rate of speed is not changed.
to bust one myth that said "If you have two same-sized balls and then fill one with sand and drop them both at same height, the result is that the heavier ball will fall first and then the other." To prove this wrong, he went to the leaning tower of Pisa an then drop two not weight same balls from the tower and they both landed on the floor she time.