On Newton's Corpuscular Theory of Light

Abstract

As is well known, Newton's corpuscular model of Light can explain the Law of Reflection and Snell's Law of Refraction. However, its predictions regarding the speed of Light in different mediums runs contrary to experience, thus, it was abandoned in favour of Huygens' wave theory. Newton's theory predicts that the speed of Light is larger in higher density mediums which was shown to be wrong by Foucault's 1850 experiment. The major assumption of Newton's theory is that the corpuscles of Light have an attraction with the particles of the medium. When the converse is assumed, i.e., the corpuscles of Light are assumed not to have an attraction-effect but a repulsion-effect with the particles of the medium, one obtains the correct predictions of the speed of Light in denser mediums. This new assumption might explain why Light has the maximum speed in any given medium.