Then we looked at the idea of calculating the pi-naught into two gamma, approximately. That had been done many, many different ways, always with the same answer. It was done back in something like 1950 by Jack Steinberger, who spent a year at the Institute for Advanced Study, and he did a calculation of pi-naught in two gamma, based on perturbation theory with a neutron and proton, and he got the answer approximately right. No, how did he do it? It wasn't exactly perturbation theory, I've forgotten what the argument was, but anyway he made a clever argument to get the answer essentially right.

Then, with the discovery of anomalies and using pole dominance, Stephen Adler and various other people, I forget exactly who they were, but various theorists showed that you would get this as a real theorem in the limit of light… light pion, and that it represented a very important quantity because it was a sum over the product of the axial charges and the… the fundamental axial charges and the fundamental electric charges squared… multiplied by the fundamental electric charges squared of the elementary objects in the theory, because those would give the... the anomaly. So Bardeen and Fritzsch and I looked into this and we saw that with color the quarks would give the right answer, and that was really... that was really beautiful.

Around this time I went to Munich—München—and gave a talk there, which Heisenberg attended, and Heisenberg had been hostile to all of the good ideas in this area. He hadn't believed in strangeness; he hadn't believed in SU(3), approximate SU(3), he said it was like approximating a cube by a sphere or something like that; and… and now he didn't believe in the quarks and he didn't believe in this calculation. He thought the correct calculation was one with neutron and proton and no color. But of course, quarks and color give the same answer as neutrons and protons and no color. We made some sort of a bet, but it was never clear enough that anyone could collect. The… then we worked further with these… with these ideas in the fall of ’71 and the spring of ’72. I gave some lectures in the winter at Schladming where I described our results a little bit.