Galileo Galilei's Challenge
The outstanding Galileo Galilei was already teaching at the University of Pisa in Italy by the time he was twenty five. No one was very surprised. Galileo showed talent from as early as when he as a child. Even before he entered the University of Pisa as a student in 1581, people believed that he could do just about anything he set his mind to. His father wanted him to become a doctor, but Galileo was more interested in mathematics than medicine.
Galileo made his first mathematical discovery in the cathedral of Pisa. Watching a hanging lamp swing back and forth, he discovered that no matter how far it swung, any complete swing took the same amount of time. If the length of the swing was 20 feet of four feet, there was no difference. He later used this principle in timing the paths of the planets, and it led to the invention of the pendulum clock.
Galileo went on to study mathematics at the University of Pisa. In 1589 he was given the post of lecturer of mathematics at that university. He stayed only for two years because some of the other professors were jealous of him. They didn’t like his attitude toward them. His discoveries were the opposite of what everyone had always believed. For a long time people thought that if you dropped a rubber ball and a hammer from the same height, the lighter object, the rubber ball would fall more slowly. But Galileo proved that objects of unequal weight fall at the same rate of speed. Many people found this new idea hard to believe. So many of his ideas were against popular opinion that he soon became disliked, and in 1591, he resigned because he could no longer work in peace.
From 1592 until 1610, Galileo was a professor of mathematics at the University of Padua. Toward the end of his stay there, he turned once again to a problem that had been bothering him for so many years. The state and the church agreed with the ancient astronomer Ptolemy, who had said that the earth was the center of the solar system and that all other heavenly bodies revolved around it. But Galileo wasn’t so sure. Perhaps Nicholas Copernicus, a polish scientist, was right. He believed that the sun was the center of the solar system; it was stationary and the earth and the other planets revolved around it.