The dualistic nature of light is discussed. The photoelectric effect and the Davisson-Germer experiment are contrasted as empirical evidence supporting each of the two views - particle and wave - of the nature of light. The photoelectric effect and its interpretation are explained. The relationship between the empirical evidence and Planck's hypothesis of the existence of photons is described.

A perfect site for the study of work ethics. Online lessons and the history of the American work ethic are particularly impressive.