In Memoriam Geoffrey Chew 1924 – 2019

Geoffrey Chew, who died last April at the age of ninety-four, was one of the deepest and most radical thinkers of twentieth-century physics. His bootstrap theory, technically known as S-Matrix theory, is based on the idea that nature cannot be reduced to fundamental entities, like fundamental constituents of matter, but has to be understood entirely through self-consistency. According to Chew, all of physics has to follow uniquely from the requirement that its components be consistent with one another and with themselves.[1]

Geoffrey Chew discussing S-Matrix theory with Fritjof Capra,
Lawrence Berkeley Laboratory, 1984; photo: Jacqueline Capra

This idea constitutes a radical departure from the traditional spirit of basic research in physics, which has always concentrated on finding the fundamental constituents of matter. At the same time, it can be seen as the culmination of the conception of particles as interconnections in an inseparable web of relationships, which arose in quantum theory and acquired an intrinsically dynamic nature in relativity theory.

The bootstrap philosophy abandons not only the idea of fundamental constituents of matter but accepts no fundamental entities whatsoever — no fundamental laws or equations, and not even a fundamental structure of space and time. The universe is seen as a dynamic web of interrelated events. None of the properties of any part of this web are fundamental; they all follow from the properties of the other parts, and the overall consistency of their mutual interrelations determines the structure of the entire web.

During the 1980s and 1990s, the bootstrap theory was eclipsed by the success of the so-called “standard model,” which is very different, as it postulates the existence of fundamental fields and their corresponding particles. Today, bootstrap physics has virtually disappeared from the scene.

However, the standard model does not include gravity, and hence fails to integrate all known particles and forces into a single mathematical framework. The currently most popular candidate for such a framework is string theory, which pictures all particles as different vibrations of mathematical “strings” in an abstract 9-dimensional space. The mathematical elegance of string theory is compelling, but the theory has serious deficiencies. If these difficulties persist, and if a theory of “quantum gravity” continues to remain elusive, the bootstrap idea may well be revived someday, in some mathematical formulation or other.

Geoffrey Chew was the main reason why I moved to Berkeley in the 1970s. My close association with him during fourteen years (1975-88) was a source of continuing inspiration for me and has decisively shaped my entire outlook on science. I first studied Chew’s writings on bootstrap physics in the early 1970s in London while I worked at  Imperial College and also prepared myself for writing The Tao of Physics. I was immediately struck by the parallels between the bootstrap philosophy and that of Mahayana Buddhism, which I summarized in a paper entitled “Bootstrap and Buddhism.” I sent Chew a copy of the paper and asked him for his comments. His answer was very supportive and extremely exciting to me. “Your way of describing the [bootstrap] idea,” he wrote, “should make it more palatable to many and to some, perhaps, so esthetically appealing as to be irresistible.”

When I wrote The Tao of Physics, I made the close correspondence between Chew’s bootstrap physics and Buddhist philosophy its high point and finale. I finished the book in London in December 1974, and in January 1975 I moved to Berkeley and joined Chew’s theory group at the Lawrence Berkeley Laboratory (LBL). Physicists in the group included Henry Stapp, Jerry Finkelstein, Stanley Mandelstam, and several graduate students. During the next ten years I attended the group’s regular meetings every week I was in Berkeley. In addition, Geoff (as he was known to his friends and colleagues) would send weekly hand-written letters to the group, in which he chronicled the evolution of his thinking about the bootstrap theory. These weekly interactions with Geoff Chew gave me a unique understanding of his thinking process and established a close relationship between us.

At the same time, I began a gradual transition from physicist to writer, and consequently spent a fair amount of time of time away from LBL. I was the only member in Chew’s theory group who did not work on physics full-time. However, this also had a positive effect. Because of my breaks from the group I could often see the evolution of our theory with fresh eyes. Geoff often told me that he appreciated very much that I was able to ask probing questions and contribute significant insights because of my special position in the group.

Looking back on that time in my life, I have come to realize that my regular scientific discussions with Chew over almost fifteen years were also my training in systemic thinking. The bootstrap theory is a theory of networks of subatomic particles in which the properties of each particle derive from its relationships to the others. This is systemic thinking par excellence. Thus, from the mid-1970s to the late 1980s systems thinking became second nature to me, long before I studied its history and achievements, and discussed them in my books.

Geoff Chew was a tremendous inspiration for me, an intellectual father figure whose thought deeply influenced my views of science and significantly shaped my career as a scientist and writer. My memories of our discussions over so many years will be with me forever.

[1] See F. Capra, “Bootstrap Physics: A Conversation with Geoffrey Chew,” in C. DeTar, J. Finkelstein, and Ch.-I. Tan, A Passion For Physics: Essays in Honor of Geoffrey Chew, World Scientific, 1985; pp. 247-86; see also F. Capra, “No Foundation,” in Uncommon Wisdom, Simon & Schuster, 1988; pp. 50-70.