New theories about light, the elementary particles and the basic forces of nature are proposed. The experiments of Kaufmann-Becherer-Neumann, Fizeau, Hertz, Davisson-Germer, Sagnac and Young are analyzed with a new point of view. The mystery of "wave-particle duality" is solved The real structures of light, photons, electrons, neutrinos, protons, neutrons and the atom are revealed. The theories are presented in a very concise, precise and simple style.