Spinning Electrons

Abstract

I FEEL that there are serious arguments against the two objections raised by Mr. Kronig (NATURE, April 17, P. 550) to the view that the electrons in the atom possess an inherent magnetic moment, a view which Uhlenbeck and Goudsmit have shown to have important spectroscopic consequences. I will consider first the second objection, which seems to me to involve implicit assumptions about the structure of the atomic nucleus which go far beyond our present knowledge of the facts or even of the probabilities. I am prepared to follow Mr. Kronig to the extent of believing that if an electron has a quantised spin when in a Bohr orbit, an electron which has the privilege of taking part in the building up of an atomic nucleus will have the same property of possessing one or more units of angular momentum or of magnetic moment. But it seems to me improbable that the electron after it has entered into the composition of the nucleus will be able, as an individual electron, to retain this angular momentum. The ‘dimensions’ of the nucleus are not very much greater than those of an electron, and as the nucleus may contain a very considerable number of electrons and protons, it must be a highly interlocked structure of a kind which scarcely seems likely to afford opportunity for the ordered spinning contemplated.