Glashow Interview

David Zierler, the oral historian at the American Institute of Physics, has done many in-depth interviews with theoretical physicists in recent years. Today I came across a 2020 interview with Shelly Glashow, which was very interesting in general, and also answered a question I had always wondered about. Glashow was my undergraduate advisor at Harvard, where I was a student from 1975-79. From what I remember, his office was more or less next door to Steven Weinberg’s. It was well-known that they had been close friends, in the same class first at Bronx High School of Science, and then at Cornell. Towards the end of my time at Harvard I heard that their friendship was over and they were barely on speaking terms, but I never knew what had happened. In the fall of 1979, they were (together with Abdus Salam), awarded the Nobel Prize for their work on the unified electroweak theory.

In the interview, Glashow explains the story from his point of view:

by the late 1970s I began to think of myself as a Nobel contender. But I was under the impression that my old friend Steven Weinberg was doing everything in his power to keep the prize for himself and Salam. In particular—at a conference that he attended in Tokyo—he went out of his way to avoid mentioning my name at all while presenting the history of weak interaction theory. I got very upset by that omission. It was the issue which terminated our friendship. In the summer of 1979, I was invited to a meeting in Stockholm, to discuss the current state of physics ideas and others. Prior to the meeting, I sent a transcript of my talk to Steve. He was violently against my giving the talk. Because it examined various alternatives to what was then known as Weinberg/Salam theory. In fact, it was an open-minded talk in which I was discussing whether their—or more properly—our theory was a correct one or not. But it was such a heated discussion that I eventually had to simply hang up on him, because I had no intention of revising my talk. And I did not.

Was his assessment of your paper accurate in your mind?

I did talk about alternatives to the Weinberg-Salam theory. Yes. I was not yet convinced that it had to be true.

And what was your sense of why this was so unacceptable to him?

He thought it would endanger the Nobel Prize that he had campaigned for and anticipated for Salam and himself.

A copy of Weinberg’s Tokyo paper is here.

In the interview Glashow is scornful about Salam’s work and the campaign to get him a part of the Nobel Prize:

… Recall that Salam made a great deal of noise about why the prize should be given to he, Salam. I’ve been told that there were dozens and dozens of nominations of Salam. In fact, there’s a whole paper written about his shenanigans, which I can refer to you; written by Norman Dombey. Everything he says is true, to my knowledge….

My Nobel Prize depended on that one paper written in 1960. Steve’s Nobel Prize depended exclusively on that one paper he wrote in 1967, a wonderful paper which applied the notion of spontaneous symmetry breaking to the—my electroweak model. So, the question arises, what did Salam do? He introduced the electroweak—the SU(2)XU(1) model in 1964. That was over three years after I did. He copied my work but did not cite me…

Do you want to comment on why then he would have been a co-recipient of the Nobel Prize with you for this copy of your work?

I’ll explain it in a moment. But let me come back to—he also claims to the first to introduce spontaneous symmetry breaking in the paper that he wrote in 1968, one year after Steve wrote his paper. But that paper even cites Steve’s paper, so it is hardly the first time. He did what each of us had previously done, but much later. So why did he get a Nobel Prize? Very simply, he was nominated many times. Because he was Director of the International Center for Theoretical Physics in Trieste, Italy and he was very close with the directors of physics institutes in many countries; almost 100 of different institutions. And many of them wrote letters, by his instruction, using his words in some cases, encouraging the Nobel Committee to give the prize to him and also Steven. All of this documented, in fact, by the paper by Norman Dombey, who had access to Salam’s files in Italy, and has copies of the letters that he sent to other people encouraging them to nominate him. So, I think he shared the prize because he made a point of doing just that.

I wrote something on the blog about Donbey’s claims here.

Zierler also asks Glashow some questions about string theory, a topic on which Glashow’s views have been consistent from the beginning:

In retrospect, Shelly—how well do you think—has both string theory and your criticism of it aged over the past 30 years?

Well, it’s hard to answer that. String theory has become an established part of physics departments throughout the world, more so in Europe than in America. We still have some universities which are proudly string-free, like Boston University. We also have an awful lot of string theorists around who are twiddling their thumbs. It is not clear that string theory is going anywhere. I expect that string theorists would disagree with that assessment. But they are actually considering many other circumstances such as black holes in other spaces than ours, and there are all kinds of interesting things being done in mathematics, in physics, elsewhere by string theorists but with no relationship to the questions that interest me. They cannot answer the questions they set out to answer. That much is clear.

That’s as clear to you—

That was clear from the beginning, I think…

… I no longer feel so strongly about string theory. Why beat a dead horse? String Theory does not answer the questions that I’m interested in. I’m sad about that. I hope that they’re wrong. I have no reason to think that their horse is, in fact, dead, but it’s dead from the point of view of being useful to my way of thinking about physics. And I think that many experimenters feel exactly the same way, because string theorists say nothing about experiments that have or could be done. They only speak of experiments that cannot be done, which is somehow not interesting.

Update: Robert Delbourgo wrote in to point to his description of what happened in 1967. Here’s the relevant part:

I have been asked by the organizers to comment upon the the birth of the standard model during 1967 and Salam’s prominent role in it. This is an excellent occasion to set the record straight and recount my view of its history; if nothing else to refute innuendos which have occasionally surfaced during the 1970s that Salam was not deserving of the Nobel Prize. That autumn of 1967 I had been in charge of organizing the seminars at IC. Because Salam was constantly on the move and hardly spent more than one month at a stretch in London, I arranged with him to give a couple of lectures on his recent research (in October, to the best of my recollection) during his spell at IC to kick off the seminar season, as it was early in the academic year. He agreed to do so even though the audience attending those talks was somewhat thin. Paul Matthews was certainly present, but Tom Kibble was away in sabbatical in the USA. My memory of his lectures is a bit indistinct nowadays, but I do remember that he kept on invoking these k-meson tadpoles which disappeared into the vacuum which induced the spontaneous breaking of the gauge symmetry: what we now know as the expectation value of the Higgs boson. The resulting model looked rather ugly – and it still is – and I admit that I paid little attention to it; nor do I think that Salam himself was especially enraptured by the model’s beauty. A week or so later, I wandered into the Physics Library and came across Steven Weinberg’s Physical Review Letter, which I noticed looked suspiciously like Salam’s attempt. I showed the article to Salam, who was rather troubled that it was almost the same as his own research, but which was of course entirely independent. Matthews and I urged him to publish his work at the earliest opportunity and this happened to be the upcoming Nobel Symposium. As they say, “the rest is history”. I hope that this account of the events at the time scotches all aspersions that Salam should not have been a prize recipient.

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28 Responses to Glashow Interview

  1. Chris says:

    Peter, thanks for an interesting post. Did you happen to see where the audio recording of the interview is? I could only find the transcript.

  2. Brathmore says:

    Do mathematicians lobby for, and fret about, whether they’ll win the famous math prizes? Or is this just in the sciences? Contrast Weinberg/Glashow with Perelman or Scholze. As science has become so interdependent, the Nobel limit on 3 per year is as stupid as the madness it engenders.

  3. S says:

    “They only speak of experiments that cannot be done, which is somehow not interesting.”

    That seems a generous take.

  4. Georges E. Melki says:

    After reading this article, I lost most of the respect I had for both the Nobel Prize and its recipients! How could those so-called “great men” be so scornful of each other? How could they be bickering like this about precedence and priority in their fields? And what is the Nobel committee doing? What a shame!

  5. Steven Malarkey says:

    Why beat a dead horse?

    Perhaps something for us all to ponder.

  6. Having taught an undergrad course in particle physics at Harvard with Glashow, and rubbed elbows with Salam in Trieste, little in this surprises me. I only attended a couple of talks by Weinberg, but … My short assessments of the 3, in the order mentioned: good guy; preening; aloof.

  7. Anonyrat says:

    Glashow mentioned his summer 1979 talk here:
    And gave a citation:
    Scenarios for Physics at LEP
    Sheldon L Glashow
    Published under licence by IOP Publishing Ltd
    Physica Scripta, Volume 20, Number 2
    Citation Sheldon L Glashow 1979 Phys. Scr. 20 283

  8. zzz says:

    that sort of politicing for a Nobel is not uniq to physics

  9. Peter Woit says:

    Looking at the Glashow spring 1979 Stockholm talk paper, I see what upset Weinberg. On page 309 Glashow claims that current phenomenology was consistent with a different model, with “Weinberg” angle 0. Weinberg likely took that as an explicit attempt to go before the Nobel committee and tell them that Weinberg’s model might be wrong so they shouldn’t give a prize for it.

  10. Peter Shor says:

    Chris asks:

    Did you happen to see where the audio recording of the interview is? I could only find the transcript.

    I am fairly sure that for this series of interviews, they don’t release the original recording but just the transcript. I don’t know why—this is pure speculation, but maybe it’s because they think more people would be willing to be interviewed this way.

  11. Anonyrat says:


    In the first link, Glashow wrote:

    “I was invited to speak about the weak interactions at a conference in Stockholm in the spring of 1979.2 While in Stockholm, a member of the Nobel Physics Committee delighted in telling me that the Weinberg angle appearing in the Weinberg–Salam model was identical to the angle I introduced in my 1960 paper. I was delighted as well.”

    The “weak mixing angle” was invented by Sheldon Glashow in his 1961 paper, “Partial-symmetries of weak interactions.”

  12. Peter Woit says:


    That’s why I put “Weinberg angle” in quotes. If you were around Glashow and his collaborators during the late 70s you were well aware that it wasn’t discovered by Weinberg…

  13. Palinuro says:

    Once I had the chance to talk with Glashow, and ask him when he was convinced that his model was true, he said that after neutral currents were observed, not 1961, not 1967 or 1971.

    Weinberg, great physics and books, but in both of them it is like if Veltman has not existed.

  14. curiouser says:

    It’s hard to understand why the theory, at least initially, was called the Weinberg/Salam model, and why “Weinberg was doing everything in his power to keep the prize for himself and Salam”, if all Salam did was to steal from Glashow and Weinberg. It’s unfortunate that Weinberg and Salam are no longer around to defend themselves against what sounds like childish bickering fifty years after the fact. Maybe they wouldn’t have cared to.

  15. Peter Woit says:


    I’m also curious where the term “Weinberg-Salam”, with non-alphabetic ordering, first appeared. If Salam had independently discovered this model and written it down, why not “Salam-Weinberg”? The model got zero attention until after ‘t Hooft showed renormalizability. ‘t Hooft in his earliest mention I can find
    refers to the model as Weinberg’s model, no mention of Salam.

    For much more detail about this story, I recommend Frank Close’s book “The Infinity Puzzle”.

    From everything I’ve read, Glashow has a good argument that Salam should not have gotten recognition for this. Writing a paper in 1964 describing the same model someone else well-known working in the same field had published three years earlier is not the kind of thing one normally gets any kind of credit for. Salam claimed to have independently discovered and discussed the Weinberg 1967 model for leptons in a series of fall term (Oct-Dec.) 1967 lectures at Imperial. There are no records from anyone of what he discussed in those lectures. Weinberg’s paper went to PRL Oct. 17 1967, was published Nov. 20, so quite possibly would have been available to Salam at some point during that period (there’s zero chance he would not have paid attention to a new paper from Weinberg).

    Glashow is almost 90 years old, and has every right (and arguably a duty) to try and set the historical record straight about the Salam story. About Weinberg, what he has to say has nothing to do with the science, it’s purely about their interpersonal conflict and why he stopped speaking to Weinberg. It seems to me he has every right to publicly explain that if he wants to.

    Weinberg was alive when Glashow was interviewed, but now can no longer respond. I doubt he would have wanted to. One can make a guess about how he felt about this: in 1978-9 he was clearly one of the first in line for the next physics Nobel Prize, perhaps had little patience for things that might interfere with this (such as arguments over claims about an earlier, incorrect, version of his model, or claims that it might yet turn out to be wrong).

  16. Shantanu says:

    Peter : in NASA/ADS you can do a full-text search
    NASA/ADS is not always 100% complete in terms of Physics papers but according to this, the first paper which used “Weinberg-Salam” model is…6.2023M/abstract
    I don’t think inspirehep does a fulltext search. If it does someone can search via that too.

  17. tulpoeid says:

    Very interesting historically, thank you. The ending with “experiments that cannot be done” is also gold.
    I remember almost fifteen years ago Glashow giving a talk at CERN. He made several jokes and everyone laughed. At some point he made a good joke against susy. Only me and a couple other people in the auditorium laughed (but at least we laughed loud).

  18. Robert Delbourgo says:

    Peter, please see my comments on page 3 of the Salam Memorial volume in the article “the force and gravity of events”. I will leave it at that. I am an old guy now and you will just have to believe me. I only wish I had kept written notes of Salam’s talks in autumn 1967. At the time I thought the whole edifice was rather ugly, especially the way he introduced the tadpole diagrams, which represented spontaneous symmetry breaking in his description.

  19. Peter Woit says:

    Robert Delbourgo,
    Thanks for writing. I’ve added your comments that you point to as an update to the posting.

    It still seems to me that it remains unclear what exactly Salam knew and lectured about before he had access to Weinberg’s paper.

    Looking back on the history of the electroweak theory, one thing that strikes me is how little interest everyone (including their own authors) seemed to have in these models. It took three years for anyone (whether Weinberg and/or Salam) to bother to put the Higgs mechanism together with a unified electroweak theory, and then that was ignored by everyone for another three years or so until ‘t Hooft/Veltman. Both Weinberg and Salam don’t seem to have been particularly enthusiastic at the time about the idea that won them a Nobel Prize.

  20. shantanu says:

    Peter: something OT. I just accidentally noticed that 1975 nobel prize winner (and another Schwinger student just like Glashow) Ben Mottleson passed away in May . Despite getting a Nobel prize in Nuclear Physics and working in this area for 70+ years, I am surprised that there is no tribute to him on this or any other blog or from other physicists (which I could find). Was his work not well known to particle physicists despite getting a Nobel prize?

  21. Peter Woit says:

    Nuclear physics is a quite different subject than high energy particle physics, and in general I think HEP physicists don’t know much nuclear physics (during my Ph.D. I learned the minimum to pass general exams). In Mottleson’s case, the Nobel-winning work was done 70 years ago. All I knew about Mottleson was that he did something with Bohr a very long time ago, surprised to hear he was still with us until recently.

  22. Peter Orland says:

    Hi from Copenhagen. Ben Mottleson won the prize with Åge Bohr, not Niels.

  23. Peter Orland says:

    He may have also worked with Niels, although I am not aware of it.

  24. Chris Austin says:

    Peter, “It took three years for anyone (whether Weinberg and/or Salam) to bother to put the Higgs mechanism together with a unified electroweak theory,”

    From Weinberg’s own account, on pages 2 to 6 of his Nobel Lecture, he was at first rather disturbed by the result that spontaneously broken continuous symmetries lead to massless Goldstone bosons. But in 1964, the year when the papers on the Higgs mechanism by Higgs; Englert and Brout; and Guralnik, Hagen, and Kibble appeared, there was another development, which suddenly seemed to change the role of Goldstone bosons from that of unwanted intruders to that of welcome friends. This was the Adler-Weisberger sum rule, which gave the ratio $g_A/g_V$ of axial-vector to vector coupling constants in beta decay in terms of pion-nucleon cross sections. One way of looking at this result was to suppose that the strong interactions have an approximate symmetry, based on the group SU(2) x SU(2), and that this symmetry is spontaneously broken, giving rise among other things to the nucleon masses. The pion is then identified as (approximately) a Goldstone boson, with small non-zero mass, an idea that goes back to Nambu. Weinberg spent the years 1965-67 happily developing the implications of spontaneous symmetry breaking for the strong interactions. In 1967 he thought of trying out the idea that perhaps the SU(2) x SU(2) symmetry was a “local,” not merely a “global,” symmetry. He considered a model where in addition to the vector $\rho$ mesons of the Yang-Mills theory, there would also be axial vector A1 mesons. But he was not too enthusiastic about it. Then at some point in the fall of 1967, it occurred to him that he had been applying the right ideas to the wrong problem. It is not the $\rho$ mesons that are massless: it is the photon. And its partner is not the A1, but the massive intermediate boson, which since the time of Yukawa had been suspected to be the mediator of the weak interactions.

  25. Peter Woit says:

    Chris Austin,
    As Weinberg explains, he and everyone else were focused on the strong interactions, trying to use spontaneous symmetry breaking and the Higgs mechanism to understand that. A lot of the reason why no one for years applied the Higgs mechanism to the electroweak theory was that everyone was thinking about the strong interactions, not the electroweak interactions.

  26. pontifex says:

    A nice rendering by Weinberg of the story of his realization that he had been trying the right idea for the wrong theory is here

  27. Hans says:


    my own interaction with Glashow was about 10 years ago was with a gentleman. I wrote him to ask him whether he thought that the weak and the electromagnetic interaction had actually been unified, or whether the two interactions mix in a specific way. (I lost the mail exchange due to a hard disk crash…)

    He answered that this was not clear-cut, and that mixing was an acceptable and possibly better description.

    For somebody who received the Nobel prize for this unification, I found this quite impressive.

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