History of Science and Engineering Annotation << Back СENTENARY ANNIVERSARY OF THE WAVE-PARTICLE DUALISM IDEA A.F. Smyk In September-October 1923, three articles by Louis de Broglie were published, in which for the first time the idea of the existence of non-material phase waves associated with the mechanical movement of a particle of matter was presented. The idea of a phase wave, later called the de Broglie wave, which consisted in the absence of a distinction between an atom of matter and an atom of light, became revolutionary. The concept of the de Broglie wave was developed by E. Schrödinger, he obtained a non-relativistic wave equation, which became the basis of the Schrödinger-de Broglie wave mechanics, which then turned into modern quantum mechanics. In this paper, the author analyzes the content of de Broglie’s articles, emphasizing the signifi cance of de Broglie’s hypothesis that light quanta are relativistic particles with a rest mass. The origins of de Broglie’s reasoning are shown, in which he combined the relations of classical mechanics, the wave theory of light and the theory of relativity. Keywords: Louis de Broglie, quantum mechanics, phase wave, wave mechanics, wave-particle duality. DOI: 10.25791/intstg.3.2023.1408 Pp. 34-39.