Einstein and Quantum Theory: The Early Years

Martin J. Klein

P. Jordan

Heinrich A. Medicus

Fifty years have passed since Louis de Broglie created the theory of matter waves and published his first papers on the subject—inaugurating the era of modern quantum mechanics. De Broglie's undertaking was a very bold one. Unlike Planck's work in the older quantum theory, which had its origin in the measurements of black-body radiation, and unlike the photon hypothesis of Einstein, where the early experiments on the photoelectric effect offered some corroboration, de Broglie's theory lacked the support of any direct experimental evidence. Had it not been for the intervention of such established figures as Langevin and Einstein, who recognized the importance of what he had accomplished, de Broglie's work probably would have had little immediate effect.

Wayne C. Myrvold

Recent literature on Bohm's alternative to mainstream quantum mechanics may create the misleading impression that, except for perfunctory dismissals, the theory was ignored by the physics community in the years immediately following its proposal. As a matter of fact, Einstein, Pauli, and Heisenberg all published criticisms of Bohm's theory, explaining their reasons for not accepting the theory. These criticisms will be discussed and evaluated in this article.

Seiya Abiko

Hrvoje Nikolić

In 1930, Einstein argued against the consistency of the time–energy uncertainty relation by discussing a thought experiment involving a measurement of the mass of the box which emitted a photon. Bohr seemingly prevailed over Einstein by arguing that Einstein's own general theory of relativity saves the consistency of quantum mechanics. We revisit this thought experiment from a modern point of view at a level suitable for an undergraduate readership and find that neither Einstein nor Bohr was correct. Instead, this thought experiment should be thought of as an early example of a system demonstrating nonlocal 'EPR' quantum correlations, five years before the famous Einstein–Podolsky–Rosen paper.