Galileo Galilei

Galileo Galilei born in 1564 was an Italian physicist, astronomer, astrologer and philosopher who is closely associated with scientific revolution. In 1581, Galileo began studying at the University of Pisa, where his father hoped he would study medicine. Galileo started experimenting with lenses on his own. He described the principles of lenses and light rays and improved both the microscope and telescope. He added a focusing device to his microscope and of course went on to explore the heavens with his telescopes.

In 1609, Galileo was the first person to use a telescope to observe the skies. Galileo discovered the rings of Saturn (1610), was the first person to see the four major moons of Jupiter (1610), observed the phases of Venus, studied sunspots and discovered many other important phenomena.