I’ve just finished reading a wonderful new book by theoretical physicist Peter Freund, entitled A Passion for Discovery. Freund grew up in Romania, and began his career as a physicist in Europe during the 1950s, emigrating to the US during the 1960s, finally ending up at the University of Chicago, where he is now an emeritus professor.
When I was writing my own book I tried to include amidst the expository material about physics and mathematics stories of some of the people and events that seemed to me illustrative in one way or another. Freund has had the excellent idea of writing a book that foregrounds such stories, interspersing in the background the actual physics and mathematics. A reader who doesn’t know the science may not learn as much about it from this book as from others, but will get a feel for something perhaps more important, the “culture” of the field of theoretical physics. By this I mean the whole circle of knowledge that makes up the context in which theoretical physicists think and work. A reader who does know the science and some of the stories that Freund tells will deepen his or her knowledge by learning many more that he or she was probably unaware of.
When I moved from a physics environment to a mathematics one many years ago, one thing that struck me was that I had entered not just a field that studied somewhat different material, but a whole new cultural environment, very much like moving from the US to France. Different fields have different unspoken sets of values and beliefs, derived from their different environments and different histories. Shared stories about the history of the field and the quirks of leading figures of the subject make up a large part of this common culture. Freund does an excellent job of capturing the culture of twentieth-century theoretical physics, and one could learn much more about this from his book than from any textbook or most standard historical treatments.
It’s tempting to repeat here some of the stories that I learned from Freund’s book, but there really are too many to choose from, so I have to just recommend that you should read for yourself. Among the physicists you can learn about here are: Schrodinger, Heisenberg, Pauli, Dirac, Stueckleberg, Feynman, Salam, Chandrashekar, Zeldovich, Landau, Touschek, Thirring, Oppenheimer (who, unlike almost everyone else, comes off badly), Nambu, and many others. A significant number of mathematicians, including Emmy Noether and Andre Weil also put in an appearance.
Freund also does a masterful job of describing the story of how mathematics and physics operated under the totalitarian systems of the last century, including a description of how the Romanian dictator Ceausescu and his wife had the mathematics institute closed down and disbanded after their daughter, who was working there, spent the night in a resort motel with one of her colleagues. He tells the stories of some of the well-known German mathematicians and physicists who either collaborated with the Nazis or joined the Nazi party, and where this led their careers. There is also quite a bit about Russian physicists and mathematicians, illustrating their attempts to survive within the Stalinist system, and the institutionalized anti-Semitism that Pontryagin and others were responsible for supporting.
Freund describes particle theory research as generally having a single leading figure that the field follows. He sees 1905 to 1925 as the era of Einstein, 1926-1943 as that of Heisenberg, a transitional period led by Fermi, with Gell-Mann dominating from the fifties to the early seventies, at which point ‘t Hooft takes over, followed by Witten in the early eighties. Witten’s long era of dominance now appears to him to be coming to an end, and Freund nominates Maldacena as the leader for the new era which I guess has already been underway for a while, as AdS/CFT has dominated research for the last ten years.
While Freund is very strong on conveying the culture of particle theory that dominated the fifties, sixties, seventies and eighties, unfortunately he has much less of the same sort of material to help explain what has been going on for the last twenty years or so, the age of Witten and now Maldacena. There aren’t any stories he has to tell about Witten, ‘t Hooft, or any of the other researchers whose work has characterized this recent period. Perhaps part of the problem is that they’re a less entertaining lot: while I’ve heard a lot about Witten over the years, I can’t think of much in the way of really colorful stories.
Freund’s take on the current state of the subject is blandly optimistic: everything’s going just fine. He mentions the Landscape and suggests Susskind’s book for further reading, but doesn’t see a problem there other than that “we need time and perserverance”, and maybe cosmology will save the day. He does promote a more realistic point of view on the prospects for string theory, seeing it as a set of ideas that may in the future be part of some quite different real advance. His analogy is with Lagrangian and Hamiltonian mechanics, which didn’t really give anything you couldn’t get from Newtonian mechanics, but were necessary foundations for the truly revolutionary quantum theory.
All in all, Freund has written a fascinating book, one which any person who wants to understand more about the culture of theoretical physics can learn quite a lot from, whether they’re a novice to the field, or have spent much of their life in it.