Owen Chamberlain's obituary (Physics Today, August 2006, page 70) contains a statement based on his early notes, which refer to me unfavorably when mentioning my (in)famous bet with Hartland Snyder.

In October 2005, at Lawrence Berkeley National Laboratory's 50th-anniversary symposium commemorating the discovery of the antiproton, Herbert Steiner gave the introductory talk and kindly included a postscript of mine, available on the internet (http://inpa.lbl.gov/pbar/talks/F3_Steiner.pdf), in which I explain my bet.

In the early 1950s, Hartland had invited my wife and me to a party. As soon as we arrived, he shook my hand in his usual tempestuous way and said, “I bet you $500 that the antiproton exists.” With no chance of explaining why I felt that the antiproton needs to be confirmed experimentally, I accepted the bet. My wife immediately said, “This is foolish,” but I was too proud to withdraw my handshake.

As Hartland may have been aware, I had been puzzling over the paradox that our world is built only of protons, even though antiprotons were anticipated. That paradox did not seem to bother anyone else then and was only much later resolved after a suggestion by Andrei Sakharov in the 1960s. Previously, I even went so far as to consider the existence of an anti-universe, 1 but did not publish that idea until after the discovery of the antiproton. Nowadays cosmologists speak even of “multi-verses,” and I was told recently that mine was the important first step in that direction.

Hartland was an honorable man and perhaps thought, because of my reservations, that he had trapped me. He did not cash the check; after his death 10 years later, his widow, financially strapped while caring for three children, cashed it. So it at least did some good.

Luis Alvarez thought the existence of my bet implied that the discovery of the antiproton deserves the Nobel Prize. A few years after the discovery, it became clear that the properties of protons and antiprotons are not completely described by Dirac's original theory, since they interact differently with leptons of different helicity—perhaps a “weak” justification for my bet!