Book

Nicolaus Copernicus’ On the Revolutions of Heavenly Spheres is a book that focuses on planetary motion. While the idea of Heliocentrism wasn’t new, nobody prior had published a complete work on the heliocentric model of the universe – one where the Sun is the center of the universe. Science and Philosophy at the time believed in the Geocentric model of the universe – wherein the Earth is at the center of the universe. Copernicus utilized diagrams, figures, and an elaborate system to map out the way planets revolved around the sun. Furthermore, the conflict of the day-night cycle was resolved by the feature of rotation, that is, Copernicus claimed that the Earth rotated around its own axis every single day. Although the sun was supposedly at the center of this model, Copernicus has used the center of his concentric circular orbits to be at a different spot than the position of the Sun. Essentially, the theory stated that even though earth and other planets are revolving around the sun, the center of their orbits is independent of Sun’s exact position. This is called eccentric. He also used epicycles in his theory. Epicycles are simply circular orbits centered around the arc of another circular object. This solution was accepted by some as the rotation of the earth around its axis was not yet discovered. Additionally, the dominant theory of planetary motion at the time of publication – the Ptolemaic model – also utilized concentric circular orbits and epicycles, albeit being extremely complicated as a tool due to the numerous amounts of epicycles.