Because the theory of quantum mechanics could explain all of chemistry and the various properties of substances, it was a tremendous success. But still there was the problem of the interaction of light and matter.

The original reason to start the project, which was that the Germans were a danger, started me off on a process of action, which was to try to develop this first system at Princeton and then at Los Alamos, to try to make the bomb work.

I've always been very one-sided about science, and when I was younger, I concentrated almost all my effort on it.

Richard P. Feynman Quotes