A Theory of Electrons and Protons(132 views)
Description: FIRST EDITION IN ORIGINAL WRAPPERS of Dirac's electron "hole" theory; the foundation for his prediction of anti-matter. One troubling consequence of the famous Dirac relativistic wave equation was that it implied that electrons should exist in states of negative as well as positive energy. Therefore a Dirac electron with initially positive energy should fall indefinitely by spontaneous emission towards states of lower and lower energy. To avoid this Dirac postulated in ?A Theory of Electrons and Protons? that the states of negative energy were normally filled up according to the exclusion principle. Holes in this ?sea? would behave like positively-charged particles. Dirac initially believed that these holes could be identified with protons, but Hermann Weyl and others showed that they should have the same mass as the electron. The following year, in the introduction to another paper (on a different topic), Dirac conceded and called these holes ?anti-electrons?. The existence of this particle was demonstrated experimentally by Carl Anderson in 1932; he called it the ?positron?. Dirac shared the 1933 Noble Prize in Physics with Schrodinger for "for the discovery of new productive forms of atomic theory". Particle Physics: One Hundred Years of Discoveries: ?Introduction of the negative energy electron sea with holes treated as positive electrons?. IN: Proceedings of the Royal Society, A126, Vol. 126, pp.360-65. London: The Royal Society, 1930. Octavo, original wrappers; custom box. Toning to wrappers, otherwise fine. Scarce in original wrappers.
Artist or Maker: Dirac, Paul