We were pleased to see that Physics Today has published a review (April 2002, page 77) of our book, Climbing the Mountain: The Scientific Biography of Julian Schwinger (Oxford U. Press, 2000), but not so pleased with the content of Tian Yu Cao’s review nor with the fact that Physics Today chose to headline it as “Julian Schwinger, But Not the Definitive Julian Schwinger.”
The review seems to us, first, to be unrepresentative. The first two-thirds of the book, which deals with Schwinger’s early remarkable career in nuclear physics, his profound work on waveguides and synchrotron radiation during World War II, his conquest of quantum electrodynamics, and his groundwork on what became the standard model, is hardly mentioned. Instead, the reviewer concentrates on Schwinger’s disillusionment with operator field theory in the late 1960s, his resulting development of source theory, and his increasing isolation from the mainstream. It is, of course, of great interest to explore that late part of his career. Indeed, the points illuminating Schwinger’s rejection of his own creation, renormalized quantum field theory, mentioned by Cao, appear verbatim in our book.
The penultimate paragraph of the review seems particularly unfair. Our book is not intended as a definitive review of quantum chromodynamics, a theory that Schwinger in fact detested. Schwinger likewise had little interest in such subjects as constructive field theory and asymptotic freedom. As for the establishment of the flavor SU(3) symmetry, we disagree with the reviewer. Although it is true that Murray Gell-Mann and others had proposed the symmetry at least as early as 1961 (as mentioned in our ref. 17, p. 408), it was not generally accepted until the discovery of the predicted Ω− hyperon in 1964. This history is important to understanding Schwinger’s 1964 work on the field theory of matter, in which he proposed an alternative symmetry group W3 = U3 × U3. By the following year, he had adopted unitary symmetry.
We were gratified that Cao found our book “extremely timely” and the anecdotes “entertaining.” However, he claims that our biography is neither “definitive [nor] scholarly.” We cannot seriously dispute the claim that it is not definitive. How can any account of a multifaceted genius be so? Particularly difficult is a subject like Schwinger, who prized his privacy, carefully erased his tracks in his writings, and was, in many ways, far less accessible than Richard Feynman. But his legacy lives on in his many students and his seminal oeuvre, so that a century from now a clearer view will be possible.
From the present vantage point, we have attempted to construct the most complete biography possible, based on extensive interviews with Schwinger, his wife, and a great many of his students and colleagues, and on close attention to his work. We do hope we have, in the reviewer’s words, brought out something “of value to those physicists, historians, and philosophers who are concerned with foundational problems in fundamental physics.” To impugn our scholarship on the basis of insubstantial failings seems unfair. Let the reader judge!
