I, somehow, had never been involved in building an accelerator, and to me it was a lot of money, a lot of expense and a lot of engineering detail, to get something that would give experiments. To me, it seemed cheaper, easier and more promising, to use Cosmic Ray particles. To be sure, they're few in number but they're huge in energy. So, after the war - no, I shouldn't jump ahead. I had not, at this point, reached that conclusion. With Gregory Breit, you worked on Pair Theory, a theory of electrons and Positrons. The creation of a pair out of electrons, one electron and one positron, out of empty space, by the collision of two Photons. You would laugh at me, I spent all day yesterday just trying to find a paper by a Russian colleague, Ivanenko, on the production of a pair, one electron, one positron, by the collision of two quanta of gravitational radiation.