Both Galileo and Shakespeare were born in Italy, in 15

Galileo Galilee was born in Pisa, Italy, in 1564. That was the same year writer William Shakespeare was born in England. It was a time of new ideas and new ways of thinking.
    Galileo’s father was a mathematician and musician. His family had been rich at one time. But now it had little money. Galileo’s father wanted him to study medicine and become a doctor. So Galileo went to the university at Pisa to study medicine.
    One day, Galileo happened to hear a mathematics professor teach a class about geometry. He was so excited by the ideas he heard that he wanted to study mathematics, instead of medicine. His father finally agreed. So Galileo became a mathematician.
    As a seventeen-year-old student at Pisa, Galileo made an important discovery. It happened at a church. During the ceremony, Galileo watched the wind swing a heavy light that hung from the ceiling. Sometimes, when the wind blew hard, the light swung wide. At other times, it swung only a little. As Galileo watched, he saw that the time of each swing seemed the same. A wide swing seemed to take the same time as a small swing. He measured the time by counting his heart beats. Galileo found that each swing took the same amount of time.
    He went back to his room and made two pendulums that swung like the light at the church. The string for each was the same length. He started both swinging at the same time. He made one swing widely and the other swing just a little. Galileo found that the two pendulums kept swinging together with the same rhythm. Later, Galileo became interested in falling objects.
    For almost two thousand years, people believed the idea of the Greek scientist Aristotle that heavy objects fell faster than light objects. Galileo questioned this. He believed the air slowed light objects that had lots of surface area. He thought that is why leaves, feathers, and snowflakes fell so slowly. He believed light and heavy objects with the same density and shape would fall at the same speed. One story says Galileo proved he was right by dropping two cannon balls at exactly the same time from the top of the leaning tower of Pisa. One cannon ball weighed ten times more than the other. People at the bottom of the building saw and heard both cannon balls hit the ground at the same time.
    Galileo had no method to measure correctly the small amount of time that it took an object to fall straight down. But he found an easy way to slow down a falling object so he could measure what happened. He raised one end of a flat surface. Then he rolled objects down it. By lowering the upper end of the surface, he could make the objects roll very slowly. Heavy objects and light objects took the same time to reach the bottom.
    Galileo’s experiments with rolling objects proved that another of Aristotle’s old ideas was wrong.
    Aristotle had taught that continuous force was needed to keep an object moving at a steady speed. Galileo found that the continuous pulling force of the Earth on objects rolling down made them speed up. As they rolled farther, they moved more and more quickly.
    Galileo also showed that an object could be affected by two forces at the same time. The explosive force of a cannon, for example, would send a cannon ball on a straight path. A second force — the pull of the Earth — would bend the flight of the cannon ball, causing it to curve downward until it hit a surface.
    The idea that two forces could influence an object at the same time helped Galileo prove that the Earth could spin without people feeling the movement. It explained how any object on the Earth could share in the spinning movement and yet keep its position. Every object is influenced by the pulling force of the Earth as well as the spinning force.