Quantum Man: Richard Feynman's Life in Science by Lawrence M. Krauss

his talents were to be exploited during the next two years: his lightning computational abilities, his mathematical wizardry, his physical intuition, his clear appreciation for experiment, his disrespect for authority, his breadth of physics knowledge from nuclear physics to the physics of materials (shortly after arriving he became ill, and in a letter to his mother reported reading a chemical engineering textbook with topics ranging from “Transportation of Fluids” to “Distillation” while in the infirmary for three days), and his fascination with computing machines.
    The physics work was quite different from his academic work. It was easier than pushing the forefront into the unknown laws, but a lot dirtier than working on pristine single electrons in hydrogen atoms. Aside from his contributions to the development of the bomb, Feynman left little permanent scientific legacy from his work during this time. (There is a formula for the efficiency of a nuclear weapon, called the Bethe-Feynman formula, that is still used today, but that is about it.)
    Nevertheless, Los Alamos had a profound influence on Feynman’s career, and it all began by accident, as so many things do. Again, in his words: “Most of the big shots were out of town for one reason or the other, getting their furniture transferred or something. Except for Hans Bethe. It seems that when he was working on an idea he always liked to discuss it with someone. He couldn’t find anybody around, so he came down to my office . . . and he started to explain what he was thinking. When it comes to physics I forget exactly who I’m talking to, so I was saying, ‘No, no! That’s crazy!’ and so on. Whenever I objected, I was always wrong, but nevertheless that’s what he wanted.” As Bethe remembers it, “I knew nothing about him. . . . He had only recently got his Ph.D. from Wheeler, at Princeton. We got to talking, and he obviously was very bright. At the meetings and seminars he always asked questions which seemed particularly intelligent and penetrating. We began to collaborate together.” And in another reminiscence, “He was very lively from the beginning. . . . I realized very quickly that he was something phenomenal. . . . I thought Feynman perhaps the most ingenious man in the whole division, so we worked a great deal together.”
    The opportunity to work with Bethe at Los Alamos was fateful in the extreme. They complemented each other in remarkable ways, sharing uncanny physical intuition, mental stamina, and calculational ability. But Bethe was, in several other senses, everything that Feynman was not. He was calm and deliberate, and unlike the excitable Feynman, Bethe was “unflappable.” This was also reflected in their mathematical styles. Bethe began a calculation at the beginning, and ended at the end, no matter how long or difficult the road between was. Feynman, on the other hand, was as likely to begin in the middle or at the end, and jump back and forth until he had convinced himself he was right (or wrong). In other areas, Bethe served as a remarkable role model. Feynman loved his humor, his unaffected manner, and his straightforward and collegial way of dealing with others. And whereas Wheeler helped free up Feynman’s enthusiasm and creativity, he was not the physicist that Bethe was. If Feynman was to rise to new, and higher levels, he needed someone he could go head to head with. Bethe was the man.
    By the time Bethe had moved to Los Alamos, he had resolved one of the most important and vexing questions in astrophysics: how does the sun shine? For over a century scientists had wondered what energy process powers the sun so it has been able to shine with its observed luminosity for over 4 billion years. The earliest estimate, by a German doctor in the early eighteenth century, suggested that if the sun were a big ball of burning coal, it could burn with its observed brightness for about 10,000 years, which happened to be in nice