Richard Feynman. I knew him at Caltech. He tutored me in Quantum Mechanics. A few things I learned from him: you cannot bullshit a good scientist. If you ca

Richard Feynman. I knew him at Caltech. He tutored me in Quantum Mechanics. A few things I learned from him: you cannot bullshit a good scientist. If you can't explain it to an undergraduate you don't understand it yourself. Experiment rules - if experiment says it's not true then it isn't, despite what theory might say - and he was a theoretician! Everyone who knew anything about him revered him as a god because he made it plainly apparent he regarded it as more important to teach Physics than to understand it himself. He must have come to that conclusion late in life, as I recently learned that as a young Cornell professor he was quite irresponsible towards his students.