Burned out after the war, I started solving physics problems for my own satisfaction — like a wobbling plate tossed in the Cornell cafeteria. That play with rotation equations proved important to my Nobel-winning science.
My undergraduate thesis gave the Hellmann–Feynman theorem, and my 1942 Princeton doctorate applied the principle of stationary action to quantum mechanics — the research basis for path integrals and my diagrams.
My Caltech research spanned electromagnetism, the weak force, the strong force and gravity: superfluid helium, the V–A theory of weak decay with Gell-Mann, partons, gravity ghosts and early quantum computing.
In my 1959 Caltech lecture I described machines built at atomic scale, chemical synthesis by mechanical manipulation, and a swallowable surgical robot — a talk now frequently cited in nanotechnology and microtechnology research.
Asked in the early 1960s to "spruce up" Caltech's undergraduate teaching, I spent three years building an introductory physics course that became The Feynman Lectures on Physics, still selling for its deep understanding of the science.
Teaching in Brazil, reviewing California textbooks in 1964 and addressing science teachers in 1966, I argued that education built on rote memorisation does not produce learning; science teaching must train doubt.
I chalked this line on my blackboard at Caltech. It sums up how I do physics: I understand a result only when I can rebuild it myself.
In my 1974 Caltech commencement address on cargo cult science I told graduates that scientific research rests on a kind of utter honesty, and that it starts with not fooling yourself.
When SLAC's late-1960s deep inelastic scattering experiments showed point-like particles inside protons and neutrons, my parton model read the research data without extra hypotheses — including the 45% of momentum carried by neutral particles.
At the Oak Ridge enrichment plant I helped engineers devise storage procedures so enriched uranium could not reach criticality, and I insisted on teaching the workers the nuclear physics behind the rules.
