Galileo Galilei had five siblings. He was the first of six children born to Vincenzo Galilei, a musician, and Giulia Ammannati. Galileo was born on Feb. 15, 1564, in Pisa, Italy.
Galileo was a mathematics professor and a scientist who is famous for his studies on the workings of the pendulum and the rates of falling objects. He developed a telescope, and his observations of the moon and planets supported the then-controversial Copernican theory, which professes that the Earth and the other planets revolve around the sun. Galileo was accused of heresy by the church for his writings on this theory, and he lived his last years under house arrest.