SLAC BEAM LINE Bj, I think you had better go to the lab now. 1985 Special- Issue Number 8 July - THE NOVEMBER REVOLUTION A THEORIST REMINISCES James D. Bjorken The discovery of the J/1, announced in the fall of 1974, resulted in such a rich flow of new physics and new experimental technique that physicists call the era the 'November Revolution.' The Symposium on the Tenth Anniversary of the November Revolution, held at SLAC SLAC BEAM LINE, x2979, Mail Bin 94 recollection on November 14, 1984, was a The Beam Line is a publication of the of the discoveries and a review of the Stanford Linear Accelerator Center, (SLAC), consequences. containing technical news and features for the staff and users of the laboratory. This issue was James D. Bjorken, now Associate Director edited by Bill Ash and Bill Kirk. a Professor at for Physics at Fermilab, was Stanford University operates SLAC under contract SLAC from 1963 to 1979, well-placed in all with the US Department of Energy. respects to record the excitement. 2 SLAC Beam Line, July 1985 THE NOVEMBER REVOLUTION Clearly action is required, and I am happy to report that Fermilab has decided to act on this issue. We are going to sponsor a workshop. I -A THEORIST REMINISCES thought it would be easy to at least get theorists J.D. Bjorken to come, because there are so many experts on topology, string tension, and all that; in fact, they are very active. But when I looked around and so- It is my task to reminisce, from the point of licited them they are all in at least ten dimensions. view of a theorist, on how the 1974 November revo- That's not likely to do us much good. lution changed our way of thinking. It seems that, it really as the years go by, I change more from making Anyway, getting back to reminiscing, looks back to the exercises in futurism to exercises in reminiscences. is fun. But it is easy when one forget all of In the past I have been almost a professional fu- past to round off all of the sharp edges, turist. But these days there is clearly no future for the difficulties, confusion, and personal shortcom- of how one would me in futurism. With the Superconducting Super ings, and bask in the reflection had things happen. This is true Collider and the Large Hadron Collider and large have liked to have level but also, I think, linear colliders, that field is overcrowded, and it not only at the personal It is not so much so when we will probably remain overcrowded for the next ten with the field itself. other. But, when we years. So I am out of the market in that activity. are communicating with each the outside would and have But reminiscences are fun too - in fact too much present the history to a lot of the complications get re- fun. When that becomes a dominant pastime, it's to simplify it, is created, with a linear clearly past time to get out of this business. moved. A new mythology line of logic. Everything progresses neatly from a Actually, reminiscing is getting to be a big ac- few ideas of the past to the orderly situation that tivity. Maybe because of the success of the field, we find now. Well, as we know, it just was not like there is a growing interest in looking at high- that. energy physics as a cultural phenomenon. The does the mythology say? Let us start historians and social scientists are moving in. We So, what the 1960s, when all of the pieces of the have our own stable of historians around Fermilab, back in model and the present orthodoxy were and they are setting up a history-of-science confer- standard We had the quarks and we had the non- ence for next spring. It is on the physics of the '50s, present. gauge theories; they had been around for and so I was asked as a consultant to comment on Abelian Charm appeared in that period. The the program. It suddenly struck me - my god, I ten years. was there. The weak mix- was there. No wonder I am into reminiscing. Higgs phenomenon ing angle was introduced in 1960. The partons I also noticed there is an anthropologist poking and hard collision ideas came in near the end of around, studying us for the last ten years. There the 1960s, along with SU(2) x U(1). Even color is a little article by her1 in the MIT journal, Tech- emerged, albeit at a rather primitive level. But nology Review. In it is an interesting quote that it was there in the mid-'60s. Why did it take so "there is no one in-house at Fermilab who can long to put it together? Why was it so hard? The tie his shoes experimentally." So, especially given point is, of course, that that wasn't all that was my new position [Associate Director for Physics there. There were lots of other ideas around at at Fermilab - Ed.], I found that an interesting the same time, and it was very confusing, really statement. It is clear that it is important, because a mess. It was only QED which was not a mess. it has been said that members of one of the most It was not a time, like it is now, for writing text- successful experimental groups working elsewhere books. The right thing to do was to write short not only can tie their shoes but check the tension monographs in paperback which could be thrown in their shoelaces by hand every half hour. 2 away in two years or so. What was some of the other clutter around? I 1 Sharon Traweek, 'High Energy Physics: A will just list some buzz words; they are very evoca- Review, Nov-Dec Male Preserve,' Technology tive. You may remember them and then fill in all 1984, p. 42. of the details: 2 John Alice et al., 'Alice in WonderCERN' nuclear democracy (never published). SLAC Beam Line, July 1985 _~~~ ~~~ ~ ~ ~ 3_ ~~~~~~~~~~~~ current algebra phenomenology, thanks to current algebra and dis- Regge poles persion theory. A big problem in going further was bootstrap a difficulty in choosing among many options. In dispersion theory the case of QED, an established theory, it was easy field algebra to know what to do. One tried to knock down the field-current identities edifice that had been built with the strongest ex- vector dominance perimental weapons that one had at his disposal. chiral dynamics But with no edifice to begin with, one instead Melosh transformation had to choose the materials with which one was SU(6)w to be built. The difficulty of choice was really only U(12) solved by accumulation of evidence. That means light cone current algebra experiment, and there is no substitute for that. Mandelstam representation One might think there could be a substitute if one Veneziano formula just followed the theoretical superheroes who even- Kallen-Lehmann representation tually led us to the truth. But when one looks at strings what those superheroes were doing, they were not flavor groups only making their truly great and profound contri- LSZ butions to the signal, but they were also contribut- Wightman axioms ing to the background. By definition, superheroes are so talented that they tend to make major con- Don't get me wrong; I don't want to put down tributions to most of the 'irrelevant' ideas as well. these ideas. Most of them are very correct, and So that method doesn't work either. There is no still relevant. They are important foundations substitute for facts and evidence. upon which many concepts that are in the new mythology are built. They may indeed serve again Let us now go on to the next stage, say from as bases for some future mythology. For exam- 1970 to the 1974 revolution. During this period ple, current algebra gave a solid foundation for there was clearly a rapid change from a state of dis- the quark-parton picture of hadron substructure order toward a state of balance between disorder as well as a description of the weak interactions and order. First of all, the quarks came into their upon which the gauge theories were built. Regge own. The deep-inelastic scattering experiments at poles are right; the theory works. Duality was im- SLAG, soon followed by neutrino experiments else- portant in giving linear Regge trajectories and the where, gave evidence for the pointlike structure first hints of the ideas of confinement and con- of hadrons and argued very strongly for fractional fining potentials. Nuclear democracy was right, charge. Spectroscopy - especially baryon spec- and very important in eliminating the old mind- troscopy - became during that period very or- set that somehow the proton was special and the derly, very beautiful, and very consistent with the delta was just an excited state of a proton rather quark model. This accomplishment consisted of than co-equal. Of course, we see nucleon and delta the accumulation of a large number of individu- now as a hyperfine doublet, but hyperfine doublet ally unremarkable experiments followed by ardu- were not the words that were used then. Never- ous phase-shift analyses. But the totality of this theless, the concept of equality in 'fundamental- effort led to a clean, beautiful picture. ness' or 'non-fundamentalness' of all of the differ- Emergent during this period was the renormal- including the stable ones, was a very ent hadrons, ization of the non-Abelian gauge theories.