In 1582, Galileo's observation that it took the same amount of time for the lamp to do one swing regardless of how far it swung led him to perform experiments. These experiments demonstrated that the period of a pendulum swing is determined by its length. Galileo Galilei (February 15, 1564 - January 8, 1642) was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope, important astronomical observations and support for Copernicanism. He has been called the "father of modern observational astronomy", the "father of modern physics", the "father of science", and "the father of modern science". He discovered the mountains on the Moon, the four largest moons of Jupiter and numerous dim stars. He studied gravity, showing that heavy and light objects fall at the same rate. He supported the Copernican theory that the Sun was at the center of the solar system rather than the Earth. This belief was judged heretical by the Inquisition in 1633 and he was sentenced to house arrest for the rest of his life. Suffering fever and heart palpitations, he died in 1642, at the age of 77.