What is an Electron? Relativistic Electron Theory and Radiative Processes

Abstract

Quantum theory originated from the remarkable behavior of electrons, light quanta and their interactions. One can take the point of view that a better understanding of quantum theory is a better understanding of the entities we call “electron” and “photon”, rather than the quantum theory being the new abstract laws of nature that we have simply to accept. For problems and “paradoxes” in the quantum theory of measurement it is important to ask what are the objects that we are trying to measure. Instead of saying that the electron or photon have particle behavior or wave behavior, we could say that we really do not know how they look like, but we can approximate them by a wave or a particle, better yet by a wave and a particle. It is worth recalling what the pioneers of the concepts of photon and electron have said after a lifelong occupation with their own creation! A. Einstein (1955): “Every physicist thinks that he knows what a photon is. I spent my whole life to find out what a photon is, and I still don’t know it”. And P.A.M. Dirac “I really spent my life mainly trying to find better equations for quantumelectrodynamics, and so far without success, but I continue to work on it”².