Galileo
...is telescope was finished, he looked up into the sky, and realized that many of Aristotle's and Ptolemy's theories about the heavens were false. Galileo's first discovery was that, unlike the theories of Ptolemy and Aristotle, the moon was mountainous and pitted much like the earth. In 1610, Galileo made his most amazing discovery: he discovered four moons circling Jupiter. He named these moons the "Medicean Planets" in hope of winning respect from the ruling family of Florence. In 1610, as well as discovering the four moons of Jupiter, Galileo became Cosimo de Medici, the Grand Duke of Tuscany's personal mathematician. This job brought Galileo back to Florence where he continued to study the heavens. Many of Galileo's observations were of sunspots and Venus. He also saw that the planets advanced in phases similar to the phases of the moon. Later in 1610, publications of his findings were made. Galileo decided to redirect his work to studying the motion of freely falling bodies. While at work, Galileo found another problem with Aristotle's work. He found that with Aristotle's theory, which said that the earth was the center of the universe and all of the planets including the sun revolved around the earth, made it seem impossible that the earth moves. Galileo’s concepts for the law of falling bodies was to see if objects of different sizes but same densities would fall at the same rate. He also wanted to demonstrate that objects of the same size but different densities would fall at rates proportional to their densities. In his early studies he found that the speed of a falling body was independent of its weight. In finding this, he resulted in an experiment called “The Tower” in which he dropped two rocks from the Tower of Pisa. In this experiment, Galileo determined tha...