There’s a fascinating new book by Frank Close out this week about the history of the Standard Model, called The Infinity Puzzle. Until now I’ve always recommended The Second Creation, by Crease and Mann, as the best popular book for this history, but Close’s new book gives that one a run for its money. While Crease and Mann is a comprehensive overview, covering theory and experiment, as well as a longer time-frame, Close gives an insider’s look focused on the decade or so that led up to the Standard Model coming together around 1973.
Knowing the history of a subject has always seemed to me an integral part of really understanding it, so I’d argue that anyone who wants to really understand modern particle physics should spend some time with a book like this. In addition, there’s an outside chance we may soon be seeing the collapse of one of the central pillars of the Standard Model, the Higgs field, and if this happens, an understanding of where the Higgs came from may very well be relevant to anyone who wants to think about how to live without it.
About a year ago I spent some time looking into the history of what I think is best called the Anderson-Higgs mechanism, writing a long posting about it here. Particle physicists have long overlooked the fact that it was condensed matter theorist Philip Anderson who not only first understood the basic physics that was going on, but even wrote a paper aimed at explaining it to particle theorists (which they ignored). Anderson’s insights grew out of his work on the BCS theory of superconductivity, a subject in which the role of gauge invariance was not so easily understood. If the Higgs field needs to be replaced, the analogy with BCS theory might provide a clue about what could replace it. Another book I’ve been reading recently is a collection of Anderson’s essays, called More and Different: notes from a thoughtful curmudgeon. Many of the people and topics he discusses there are much less familiar to me, but I confess to enjoying the curmudgeonly tone, and wishing I knew more about the history and physics behind the superconductivity research that he describes. Included in his collection is a review of my book I was very pleased by. His prediction about what the LHC will see is one I’m very sympathetic to: no supersymmetry, and “we will probably discover unexpected complexity in the Higgs phenomenon.”
Anderson is justifiably scornful that the APS awarded the
Dannie Heinemann prize [Anderson's mistake, it was the J. J. Sakurai prize] for work on the Higgs to no less than seven [actually it was six] people, managing to leave out Anderson. Close gives Anderson his due, but also gives by far the most detailed and well-researched account available of the work of Higgs, Brout, Englert, Guralnik, Hagen and Kibble in this area. He puts the most dramatic revelation from his research in a footnote (page 388):
A bizarre coincidence is that on Monday, October 5, just a week before Guralnik, Hagen, and Kibble’s paper was received by the editor of Physical Review Letters in New York, and hence around the time that it would have been submitted to the journal, Peter Higgs gave a seminar about his mechanism at Imperial College. Neither Guralnik nor Kibble has any memory of this, and extensive correspondence between us has failed to shed light on this.
If the Higgs particle does show up at the LHC and the Nobel committee starts debating who should get the prize, this may become relevant. Another thing that I learned from Close that argues for Higgs in this context is that he was the first (in 1966) to write down a model
with Yukawas giving masses to the fermions [Oops, this is wrong, my misunderstanding of a footnote that I didn't check. It was the gauge boson masses being referred to].
Close knows especially well the British cast of characters in this story, and one issue he devotes attention to is the unusual story of J. C. Ward’s eventful career and the question of why Ward and Kibble [as well as Guralnik] weren’t the ones to come up with the Weinberg-Salam model. Ward and Salam had worked on unified electroweak theory, minus the Higgs, and Kibble was very much involved in the Higgs story. One of the factors at play according to Close’s account was Ward’s rather paranoid nature, which made him unwilling to share ideas.
Another Nobel-related part of the book that will likely be controversial is the discussion of Salam’s case for sharing the Nobel with Weinberg and Glashow. This topic recently was raised by Norman Dombey in a preprint on the arXiv (discussed a bit here), which refers to Close’s book. Close gives a detailed description of Salam’s activities around the time he was supposedly doing the Nobel Prize winning work, raising the possibility that he may not have had the right idea independently of Weinberg. One thing that is clear about this particular story though is that no one involved, including Weinberg and Salam, understood the significance of the Weinberg-Salam model at the time.
An argument might be made that the book has quite a lot of “inside baseball”, about who exactly did what, and what people’s relative cases for recognition might be. If you really detest this sort of thing and want nothing but the physics, maybe you should stick to The Second Creation. But, if like me, you’re fascinated by this history and want to learn something new about it, go out and get a copy soon.
Update: I should make it clear that what I wrote here about Salam is my own interpretation of the story, not that of Close. He explains that Salam learned about the Higgs mechanism from Kibble, and had a unified electroweak theory with Ward, so it makes perfect sense that he would come up with Weinberg-Salam, independently of Weinberg, and he was lecturing about something. Still, the lack of any written record of exactly what Salam had pre-Weinberg makes one wonder…
Update: For the first-hand case that Salam did lecture on the Weinberg-Salam model pre-Weinberg (which is also described in Close’s book) here’s this from Robert Delbourgo:
There have been murmurs on your blog-site, following Dombey’s article I think, which cast doubt on Salam’s worthiness for the prize. I wish to refute the innuendos and aspersions which are circulating.
I was indeed present at the talks given by Salam on SSB for weak interactions where the famous model was described. Paul Matthews also attended, but being Oct that year, Tom Kibble was away on sabbatical at Rochester. I am prepared to take an oath on that.
It was more than one lecture, but I cannot remember whether it was two or three talks which he gave as it quite long ago. Then I went to the library and spotted Weinberg’s paper, newly arrived, and pointed it out to Salam and urged him to write up his own independent discovery ASAP. Matthews also encouraged him to do so and the first opportunity was the Nobel Symposium. That is the long and short of it.
I hope that ends the the rumours and controversy!!!