The different approaches between Kepler and Newton in determining the force laws

Abstract

One of Kepler’s most significant contributions to science was finding planetary motion laws, which is the foundation of celestial mechanincs. Kepler’s laws of planetary motion were not merely guesswork. He tried to apply his understanding of the relationship between force and distance to explain his planetary laws’ physical reason. However, there is usually no akcnowledgement in introductory physics textbook to the topic of Kepler’s laws regarding how Kepler tried to explain his planetary laws. Most of the introductory physics textbooks only give Newton’s description explaianing Kepler’s laws of planetary motion. This paper describes different approaches between Kepler and Newton in determining the force law and discusses some of its pedagogical implications.