Seeing my name on a list of physicists influenced by John Wheeler, which appeared in the article by Terry Christensen (PHYSICS TODAY, April 2009, page 55), triggered a flood of stories no doubt colored by my imperfect memory.
One reason I went to Princeton University as an undergraduate was that I had read about a Professor John Wheeler suggesting that the atomic nucleus might take on the form of a doughnut. When I got there, I learned that Wheeler was going to give a novel type of course for freshmen. A group of us were asked a few physics questions by Wheeler, and those who answered correctly were allowed into the course. The first homework assignment consisted of standing for 15 minutes in front of the house that Albert Einstein had lived in. It turned out that we were to learn physics from the top down: For example, we were taught “F = ma” as a limiting case of special relativity. If I remember correctly, the department did not allow Wheeler to teach the course again. But I learned a lot; in particular, I learned to “never calculate without first knowing the answer.”
One day Wheeler gave me a dollar and told me to go buy a kitchen sponge at Woolworth’s. I am proud to say that a photo of that sponge would eventually show the physics community what spacetime foam looked like.
At the end of my sophomore year, I went home to Brazil. Two months earlier the country’s military had seized power in a dramatic coup. One day, to my parents’ alarm, I received an urgent telegram from Wheeler asking me to liberate his collaborator, the eminent Brazilian physicist Jayme Tiomno, from military arrest! How he expected a stateless Chinese teenager to accomplish that is unclear to me still.
Wheeler’s inspirational mentoring of students is legendary. During my junior year, I had the privilege of doing research with Wheeler on the emission of gravitational waves from a vibrating and rotating neutron star. I had the disquieting sense that I was doing nothing more than plugging in the appropriate textbook formulas, but when I showed Wheeler my notebook, he would be wild with enthusiasm, giving me the illusion that I had actually done something. In elegant penmanship, occasionally adorned with a drawing of a dish of ice cream, he would write down what he wanted me to do next. Later I was astonished to see, in a long article he wrote for the Annual Review of Astronomy and Astrophysics , references to a paper to be published, written by Zee and Wheeler. That paper, which would have been my first, was never actually published. I regret it somewhat, as it would be just about the only one with me as the first author.
For my senior thesis I abandoned general relativity for particle physics and switched my allegiance to Arthur Wightman. When it came time for graduate school, I should have asked my thesis adviser for advice. Instead, I vividly remember sitting in front of Wheeler, who told me his opinion of the leading particle theorists at various major universities and ended with the pronouncement that Steve Weinberg was the best of the upcoming generation. It turned out that Weinberg was about to leave Berkeley for Harvard, and thus I went north rather than west for grad school.
Due to some convoluted circumstances, I did my thesis with Sidney Coleman, who was not even on Wheeler’s list. Nevertheless, Weinberg did influence me greatly, directly through his papers and indirectly in arranging for me to write my first popular physics book many years later. Thus Wheeler shaped my life in more ways than one.
