A new derivation of the quadratic equation for the masses of the proton and electron
1. In this paper I introduce some improvements of method which will, I think, bring about a considerable simplification of most of the physical problems treated in Part II of my book, Relativity theory of protons and electrons (hereinafter referred to as P. and E. ). They also facilitate the extension of the theory to other problems awaiting solution. Here I confine myself to one of the problems, namely, the derivation of the fundamental quadratic 10 m 2 - 136 mm 0 + m 2 0 = 0 for the mass m of a proton or electron. The derivation in P. and E. is, I believe, valid, though it now appears clumsy. But a proof giving more physical insight was greatly to be desired, since a thorough understanding of the underlying meaning of this relation is the first condition for a general advance. A general acquaintance with the relativistic theory in P. and E. must be presumed; but, as it happens, there is little occasion to refer to the more specialized parts of the theory.