Newton’s Bucket (Thought) Experiment

Abstract

The bucket experiment in Newton’s Principia is quite simple. Nonetheless, physicists as well as philosophers and historians of science are still debating its purpose and success. I present two interpretations found in the literature. According to the first, Newton tries to prove absolute rotation and thus the existence of absolute space. According to the second, he tries to provide a definition of absolute rotation as it is used in his mechanics. Closely connected to this is his rejection of Descartes’ explanation of rotation and of motion in general. I conclude with a short discussion on whether the bucket experiment can be classified as a thought experiment.