Back in the time of the Greeks, Aristotle and Ptolemy were the leading thinkers of their time. ... He wrote a book at this time called "The Mathematical Collection," which later came to be called the Almagest. In his book he described how he believed the Universe worked and the vision of the Universe that he put forward was one that would be adopted for many centuries, until technological improvements proved his theories wrong. ... As I said above, they believed that planetary motion was in the form of perfect circles (diagram 4) and by adjusting the velocity of these concentric spheres ...

• Word Count: 1020
• Approx Pages: 4

In 1543, Nicolaus Copernicus published Revolutions of the Celestial Orbs, which put forth his revolutionary idea that the Sun was at the center of the universe, opposing the popularly accepted understanding of the geocentric universe embodied by the natural philosophy of Aristotle, the astronomy of Ptolemy and the teachings of the Church that the stationary Earth had the sun and stars revolving around it. ... He stated, "If you would resolve to commit to print those ideas that you still have in mind, I am quite certain that they would be most acceptable to His Holiness, who never ceases from a...

• Word Count: 881
• Approx Pages: 4
• Has Bibliography
• Grade Level: Undergraduate