The Conception of the Meson Field Some Reminiscences and Epistemological Comments [1968e]
It is difficult to recapture the sensation which the discovery of the neutron produced among the small group of physicists who were then just beginning the investigation of the nuclear structures. The reason for the excitement was that this discovery at once brought some relief to the critical situation that had arisen concerning the role played by electrons in the constitution of nuclei. Squeezed within the volume of a nucleus, these electrons were expected to show extreme relativistic behaviour, and the relativistic quantum theory of the electron, according to which strong electromagnetic fields would lead to transitions to slates of negative energy, offered no reliable guidance. Experimentally, the newly measured value of the spin of 14N suggested that the intranuclear electrons somehow lost their spin; the scattering of γ-rays by nuclear electrons proved equally intractable. Such difficulties instantly vanished if one regarded the neutron, instead of the electron, as a nuclear constituent besides the proton. Heisenberg, taking up the new picture of the nucleus with his wonted vigour and directness of approach, was soon able to show that it could form an adequate basis for a comprehensive account of nuclear phenomena. Certainly, it could not remove all difficulties; those connected with β-decay remained as acute as ever: there was apparently a loss of energy and spin in the process, although the initial and final states had both definite energies and spins.
KeywordsCosmic Radiation Particle Aspect Meson Field Relativistic Quantum Theory Epistemological Comment
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