Abstract

We have seen the power of Dirac's equation, when all of it is taken seriously. In a sense, though, Dirac took it even more seriously. It is not an equation of the electron, as it is popularly called. It is a relativistic generalization of the Schr?dinger wave equation, which is said to ?contain most of physics and all of chemistry.? Dirac thought of it as a Theory of Everything?he thought that its solutions should include ?everything that waves,? i.e. every possible particle. As he was deriving it, he hoped it would have only one solution - the one, unitary particle out of which everything could be made (Dirac, 1933). Then, when he found that it had multiple solutions, he thought that one of its solutions must be the proton?as at that time, the proton and the electron were the only known particles, and it was fervently believed that they were the only particles. This is why Dirac, in several of his early attempts to use the equation, entered in as the mass the average mass of electron and proton (Pais, 1994). This didn't work, convincing him that the other ?real? particle (the other positive energy one) had to have the same mass as the electron, but the opposite charge. Thus he predicted the positron, but gave up his dream that his equation was a ?Theory of Everything.? (Of course the discoveries of the neutron and the positron, and the conviction that the photon also was a particle, didn't help any.)