I would say the more important event was quite outside of my life's work, the arrival of Max Delbruck. Now Max Delbruck was, I think, one of the great personalities of those times. He was a physicist by training, a man belonging to one of the very highest families in Prussia, in many ways a great liberal, in many ways a great authoritarian. Max Delbruck had been told in the '30s, according to rumour, that he was just not good enough to be doing physics as well as he hoped; that while Bethe would spend a few hours and write seventeen pages of flawless mathematics, and Weisskopf wrote only fifteen, but equally flawless - and Pauli always preferred Bethe to Weisskopf because of this difference - well, Delbruck only wrote five and there were bugs to fix. He was not up to this competition, which he was finding himself in. But he had branched into biology, the first physicist (to do so). Schrödinger had written about him in his book What Is Life? Delbruck had suddenly become a challenge. And the challenge was met by an equally remarkable man named Beadle who was a farmer from Nebraska who had gone to university to learn more about corn to improve the yield of his farm and moved on, and by that time had become the chairman of the Biology division at Caltech. Beadle was a very bold person. He hired Delbruck, who knew no biology, and told him, "You go and learn biology by teaching Biology One to freshmen, and then go on and do your thing," - which was to introduce quantum mechanics ideas into biology. Now, I never knew what they were doing. They were very - I wouldn't say secretive, they were just a little elusive. They never said what they were doing. Well it was clear they were doing something extraordinarily exciting which for me was again this very strong hope of bringing hard mathematical or physical thinking to a field, which had been very soft before.