Photon Mass

The nature of light has been studied by scientists since the Renaissance. According to some scientists, light had a wave nature. Others defended the corpuscular theory of the origin of light. To the founders of the wave theory, in the first place, should be attributed Rene Descartes. He represented light as a disturbance in the world substance [1]. The founder of the corpuscular theory was Pierre Gassendi [2]. The same point of view was followed by Isaac Newton [3]. Later, the wave theory of light was investigated by Robert Hooke [4] and Christian Huygens [5]. Thomas Jung [6] in the early 19 th century, his experiments with diffraction received evidence for the recognition of the wave theory. In his opinion, different colors correspond to different wavelengths. In 1817 the wave theory of light was followed by Augustin Fresnel in 1817 [7]. When considering the problem of thermal equilibrium of an absolutely black body, Max Planck [8] formulated his idea of the emission of light by portions light quanta, which were called photons. Experiments of Malus and Bio [9] with polarization provided, as it seemed then, convincing evidence in favor of corpuscular theory and against the wave theory. In quantum mechanics, the idea of Dui de Broglie [10] about corpuscular-wave dualism was confirmed.