Wolfgang Pauli and the Search for a Unified Theory

Abstract

It has been customary for historians investigating the background to quantum mechanics to concentrate on one or other of the particular branches of quantum physics. In some cases this approach may be vindicated by a similar specialisation on the part of physicists whose work is being discussed. But even though they may have published only within restricted areas, most physicists took their perception of the problem complex from the wider field of their reading, correspondence and conversation. And most of those involved in the actual development of quantum mechanics had already contributed important work in several distinct areas. In general, the major conceptual issues ran through all such areas, and their most obvious and widely discussed manifestations were not necessarily their most significant. The wave-particle duality, which was almost certainly the most characteristic conceptual feature of quantum theory, was most commonly discussed in the contexts of experimental X-ray physics and individual absorption and emission phenomena. This discussion reached its peak, in the years immediately before the development of the new quantum mechanics, in the context of the Compton effect, viewed by at least one historian as a turning point in physics.¹ But by the time of Compton’s experiments this whole area had long been one of only secondary importance for the active development of ideas pertaining to the duality problem, and dramatic though his results were to a wider audience they had relatively little impact on the physicists whose work was to be of importance in the creation of quantum mechanics.²