Near the end of the 16th century, a man named Galileo was born in Italy.

He eventually became a mathematics teacher despite having no degree, and it was here that his famous future was first hinted. A baby step towards Galileo Galilei astronomy was when he demonstrated to students that different weight objects fell at the same speed, counter to Aristotle's teachings. Aristotle was so popular that Galileo soon lost his teaching job, and so sought work in Padua. It was here that his astronomy career began.

He began to study Physics and invented a new measuring device, the compass. He developed formula for the path projectiles took, and for falling bodies. These two ideas were key to astronomy as it progressed. However except for an allegiance to the work of Copernicus over Ptolemy and Aristotle, Galileo claimed to be disinterested in astronomy. Copernicus' theory was of a heliocentric solar system in which the planets circle the sun. But in the work of Ptolemy and Aristotle the solar system circled the Earth. As time went by Copernicus, and Galileo, were proven correct.

Shortly after the spyglass was invented in Holland Galileo decided to make his own for peering at the night sky. This telescope magnified objects 20 times, which was enough to make out craters and mountains on the moon. He also learned that the milky way was made up of individual stars. Next he found the four largest moons of Jupiter. After publishing this information, he was named the royal mathematician in the court at Florence. No longer having to earn a living teaching, he could spend more time exploring. In only 9 months he determined that other planets had phases. This further contradicted Ptolemy while proving that Copernicus was right.

Galileo most disagreed with Aristotle. Because so many agreed with Galileo his theories were widely published. But Aristotle was popular with the church because an Earth centered solar system put man's home, and thus man, at the center of things. In 1614 a priest in Florence denounced Galileo Galilei Astronomy. Galileo retorted that the bible has no bearing on science. In 1616 Galileo was ordered to stop teaching that the Earth revolves around the sun. Galileo complied, continuing his study of falling objects, comets, and methods to determine longitude at sea based on the phases of Jupiter's moons. It was upon signing a document stating the Earth is stationary Galileo uttered a famous quote. "I would say here something that was heard from an ecclesiastic of the most eminent degree; "And yet ... it moves."