The scientific revolution could have dated its beginning with the work of Copernicus and its apex with the work of Isaac Newton. However, most discussions about the motivation of Copernicus and Kepler to develop their work have been inaccurate. This article describes issues regarding the current version of the complexity of the epicycles in the Ptolemaic system as the key issue that led to the Copernican revolution. It also raises a insight Kepler might have had to develop what would be known later as Kepler's first law.
Copernicus; Kepler; epicycles; ellipse
