Galileo Galilei (1564-1642) was an Italian astronomer and physicist who is well known for the invention of the first telescope.
He heard of the spyglass from Holland and used that to make a more powerful version to create the telescope. This first version was about as powerful as a modern field glass. This was the first exhibited telescope on record.
Galileo entered college studying medical professions. Later, he switched over to philosophy and mathematics. Years later, he became a professor under these professions.
Galileo got in trouble for some of the experiments that he did and even got thrown in jail. One of his most famous experiments was when Galileo dropped two different size and different weight lead balls off the Leaning Tower of Pisa. The balls dropped at the same speed and hit the ground at the same time.