A portrait of GalileoGalileo Galilei (1564–1642) was an Italian scientist. He made important advances in the understanding of gravity and motion. He was also an astronomer. Using a recent invention, the telescope—which he perfected for his needs—Galileo was able to observe the stars and planets more closely than was ever possible before. Galileo based his scientific ideas on observation and the results of experiments. He also made detailed records of his work. For this reason he is known as the Father of Modern Science.