Galileo Galilei

lived from 1564 to 1642

Galileo Galilei was an Italian scientist who formulated the basic law of falling bodies, which he verified by careful measurements. He constructed a telescope with which he studied lunar craters, and discovered four moons revolving around Jupiter and espoused the Copernican cause.

Find out more at:
http://www-history.mcs.st-andrews.ac.uk/Mathematicians/Galileo.html