The aim of this lecture is to present on Greek Astronomy Philosopher: Galileo. Italian scientist and scholar Galileo made pioneering observations that laid the foundation for modern physics and astronomy. He spent most of his life trying to prove the theories of Copernicus. He was the first to effectively use the telescope. He has been called the “father of observational astronomy”, the “father of modern physics”, the “father of scientific method”, and the “father of science”.