Archive of historical materials
Lecture: Current Status of Theory of Cosmic Rays
OU1938-C2 (8 pages) Date: November 10, 1938
This is the manuscript of the lecture given in the 144th Physics Colloquium held on November 10 in the large lecture hall in the School of Science building at Osaka Imperial University.
Yukawa began the lecture by stating that he presented a general view, “Present Status of Theories Pertaining to Cosmic Rays,” in the Physics Colloquium held on November 26, 1936, just about two years prior. He said that the remarkable advancement of experiments and theories from the time of the previous colloquium led to the findings that cosmic ray showers might consist of electrons and photos, that there were soft components and hard components and that the hard components were believed to be “heavy electrons” with the mass of halfway between the mass of electron and that of proton. He stated that those discoveries had changed the interpretation of cosmic rays dramatically.
Yukawa explained how cosmic ray showers were produced in the atmosphere. He focused on the interpretations of the generation of the hard components (heavy electrons and varitrons) and the processes of energy loss and absorption by using Yukawa’s scalar particles and by using Heitler’s vector particles. He also talked about Euler-Heisenberg’s theory. Though it was a physics colloquium, the contents of his lecture were very advanced. (Written by Yutaka Hosotani)
