The Properties and the Nature of Light: The Study of Newton’s Work and the Teaching of Optics

The history of science shows that for each scientific issue there may be more than one models that are simultaneously accepted by the scientific community. One such case concerns the wave and corpuscular models of light. Newton claimed that he had proved some properties of light based on a set of minimal assumptions, without any commitments to any one of the two models. This set of assumptions constitutes the geometrical model of light as a set of rays propagating in space. We discuss this model and the historical reasons for which it had the head-primacy amongst the relevant models. We argue that this model is indispensable in structuring the curriculum in Optics and attempt to validate it epistemologically. Finally, we discuss an approach for alleviating the implicit assumptions that students make on the nature of light and the subsequent interference of geometrical optics in teaching the properties of light related to its wave-like nature.