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Credit: Mariana Cook
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Interview of Chris Quigg by David Zierler on 2021 July 15,Niels Bohr Library & Archives, American Institute of Physics,College Park, MD USA,www.aip.org/history-programs/niels-bohr-library/oral-histories/45461
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In this interview, David Zierler, Oral Historian for AIP, interviews Chris Quigg, Distinguished Scientist Emeritus at Fermi National Accelerator Lab. He discusses his current book project Grace in All Simplicity with his colleague Bob Cahn, and he recounts his upbringing in Pennsylvania and his early interests in science. He describes his undergraduate experience at Yale where he worked with Itzhak Kelson, and his fascination with accelerator physics. Quigg discusses his decision to attend Berkeley for his graduate work and his formative summer work at Livermore. He describes the influence of J.D. Jackson’s course on the dynamics of strong interactions and how he developed his research on rho meson resonances under Jackson’s direction. Quigg discusses his postdoctoral and then faculty position at Stony Brook, and the dual attractions of Brookhaven Lab and the Institute for Theoretical Physics under the leadership of C.N. Yang. He describes his work on two-Reggeon exchange reactions and his interest in the deep inelastic scattering results coming out of SLAC at this time. Quigg discusses the circumstances leading to him joining Fermilab, and he discusses the import of research on weak neutral current, the W and Z bosons, and the Glashow-Weinberg-Salam theory. He describes the fundamental importance of Lederman’s discovery of the Upsilon, and he discusses his contributions to the research going on at CERN in the 1970s. Quigg recounts his involvement in planning the Superconducting Super Collider (SSC) and he describes his work thereafter at Lawrence Berkeley Laboratory (LBL). Toward the end of the interview, Quigg shares his ideas on the current state of high energy physics and the ongoing prospects for fundamental discoveries.
OK. This is David Zierler, oral historian for the American Institute of Physics. It is July 15th, 2020. It is my great pleasure to be here with Dr. Chris Quigg. Chris, thank you so much for being with me today.
It’s a pleasure. Good to meet you.
OK. So to start, would you tell me please your title and your institutional affiliations, and I put an “s” on the end because I know we have multiple.
Well, at the moment I’m called Distinguished Scientist Emeritus at Fermi National Accelerator Lab. I also have connections, formal and informal, with a number of European institutions, CERN, the Technical University of Munich, École Normale Supérieure in Paris…
Now, is the distinguished title — what would be the equivalent in an academic context? Would that be like a named chair emeritus?
That’s the idea, yes. And emeritus because a little over three years ago, I stopped taking money from the lab. Fermilab had always given me extraordinary freedom. I wanted even more. And it seemed that there was an opportunity for our group not to lose my salary if I were to stop taking it at that point and to invest in some new blood, which was very appealing to me. When I’m in the country, which is a bit more than half the time, I do go to Fermilab every day except in the current extraordinary circumstances. And so that’s the story behind the “distinguished” and the “emeritus.”
And how many of your colleagues hold that title also at Fermilab?
Oh, good question.
I mean is it several or are you the only one?
No, no. It is several. And within the theory group, it’s also a good number. Maybe a half dozen, something like that.
Chris, can you tell me a little bit about the book you’re working on these days?
It’s a book that I’m writing with my colleague Bob Cahn, a friend from graduate school and a scientist at Berkeley, Lawrence Berkeley Lab. The working title is Grace in All Simplicity, and it’s about particle physics broadly understood. We used to say, when we started this an embarrassingly long time ago, that it was for readers of The New Yorker. So for curious people without necessarily a background in science. No equations, no illustrations, lots of words, some stories. It includes a good deal about how we got to this point in our understanding of particle physics, where we’re going in the future, and so on.
Oh, well I’m an avid reader of The New Yorker, so I’m excited already.
Well, and you’re a writer so you know the pleasure that is pain that comes from doing these things.
And as in scientific research, you know, the reluctance to let go because you’re having so much fun thinking things through and finding them out. It’s a discipline that we need in science and we need in writing as well.
And what was the catalyst or the motivation for taking on this popular, broad-based project?
[Laughs] I think we were deranged. No, originally we started talking about this at the time the SSC [Superconducting Super Collider] was going to happen. So it was motivated by that — communicating our excitement for that.
So there’s a really long gestation period on this publication.
A very long gestation period, that’s right.
Very good. All right, Chris. Let’s take it all the way back to the beginning. Let’s start first with your parents. Tell me a little bit about your parents and where they are from.
Both of my parents are from Bethlehem, Pennsylvania, both from immigrant families, so they were both first generation Americans. My mother is from Polish parents. She was born in Bethlehem in 1919. My grandfather was a steelworker. He operated a crane that moved things around at a steel plant. Bethlehem Steel was the second largest steel company in the country. There were many eastern Europeans who worked there, and in particular my grandfather had come from Krakow. He seemed to be rather a clever man. He didn’t have a great deal of education, but he had a lot of common sense and so his job was actually one that required a certain amount of technical understanding.
My grandmother had come, I think when she was 15, from Silesia in Poland and came with a couple of friends. She actually worked Carmen style, rolling cigars in Allentown, Pennsylvania when she first arrived. It’s hard on both sides [of my family] and in the case of all sorts of people to understand how desperate they must have been or what opportunities they saw, you know, the golden arches in the United States, what drove them to come here.
My mother was the second child. She went to nursing school, so she was the first to have that level of higher education. Wonderful person. She died a few years ago at 95 and a half. She had lots of books in the house. Always encouraged us to read. We could read anything, it didn’t matter what it was, but she was very much into that. So a very strong influence in my life. She had a couple of younger sisters, one of whom was, in the tradition of those families, the maiden aunt who stayed at home and took care of her parents forever. Also a wonderful person. And then the youngest sister followed my mother into the nursing profession. All of them lived in Bethlehem for all of their lives, essentially, and so that’s part of the family that I knew very well. My grandparents, in fact, lived a block and a half from us on the same street.
My father’s family was Irish. They came here with one child, his oldest sister, and then had in sequence a total of six children. My father [born 1916] was the fourth, I think, in that line. I never really knew my Irish grandmother, because she died when I was a year and a half old, of cancer. My mother was her nurse, and that’s how my parents met. So even though I never knew this woman, she was obviously of great importance to my existence.
In what town did your parents meet?
In Bethlehem. People weren’t leaving at that point.
My father had the good fortune to be a superb athlete and in particular a very good football player. So that gave him a chance to go to college, which was unusual. You were supposed to earn a living after all, in those days. He was recruited by Princeton and they actually sent him to a prep school in Princeton because they had somebody else in line for his position. They wanted to keep him on hold for a couple of years. And either he or his parents got impatient and so he eventually went to Lafayette College and was a serious football player there. So that got him a college education, which no doubt was important to him, certainly important to me that he had had that background. He graduated from college in 1940 and went into the Navy and served in the South Pacific on a light cruiser. I was born on a naval base in Bainbridge, Maryland because he had come back from the war and was, I think, engaged in physical training for new recruits, and my parents were living there. After the war —
Chris, did your father talk about his experience in the war at all?
Only that it was terrible. It was very interesting… of course I came of age during the Vietnam period. He was a man who was a true patriot, probably a super patriot. Well, maybe not quite, but very patriotic. Believed in his country. But after his experience, he wanted me as far as possible from military service. Very interesting. You know, we see people now coming back damaged and I think he was damaged by his experience in the South Pacific.
Perhaps also he knew that the Vietnam war was a very different kind of conflict than the World War 2.
I have said to my wife that I think if I had gone to Canada [to avoid the draft], he would have disowned me. And if I had enlisted, he would have killed me. It was conflicting for many people.
So you needed a low draft number, that was the solution.
I had bad vision and a high draft number and a student deferment. Anyway, when he came back from the war, he got a job with Bethlehem Steel like everybody else, but because he had been through college, he was something called a sales engineer. He sold and gave advice about reinforcing bars and bridge railing and guardrail and things like that. Traveled the country or at least most of the eastern part of it on road jobs. When I was first conscious, he was in Philadelphia. So we lived near Philadelphia for a short time. Then he was called back to the home office, as they called it, in Bethlehem. That’s really where I grew up from second grade on.
Now, did your father have a formal background in engineering or he sort of taught himself on the fly?
He had taken some courses, you know, I think he taught himself on the fly. He had, from college, a beautiful drafting set, which he gave to me when I was in high school.
Did he involve you at all in engineering discussions when you were a kid?
He would take me during the summers on some of his road trips. You know, because he was a physically impressive specimen, for the age. I mean he was all of 6 feet tall, at the time that qualified as a specimen. And he had a very easy manner — the gift of gab, you might say — so he would go out and deal with the rod busters, the guys who were throwing reinforcing bars around and things like that. And so I got to experience some of that with him. Never anything very technical, although he certainly understood the advantages of steel over aluminum, which he might have exaggerated.
Anyway, he was not an intellectual, but he was somebody who had a very strong respect for learning. And encouraged me and my curiosity from earliest times. I guess I never saw him with a book in his hand, whereas my mother always had one, but he would read two newspapers every night. He was connected to the world.
Chris, I’m curious if growing up, you had an interest in physics before you even knew it was physics either in terms of tinkering or perhaps a fascination with the Space Race or the Cold War or anything like that? Even before your formal exposure to physics.
So I did. I was always playing with things. I used to call it “playing with electricity.” I think some of it curiously was inspired by my grandfather, who after all was driving around this big electromagnet all the time. And so I did the things of wrapping bell wire around a railroad spike and making an electromagnet and discovering for myself that when you closed the circuit, the wire got hot. I discovered resistance all by myself! There were things like that and then I of course had a chemistry set like kids did in those days. Pretty tame stuff actually, I never really blew up the house or anything, although there were certain funny smells that emanated from that.
My mother let me play around in her kitchen a lot, so that was a form of experimentation I think. And those failures made me the cook I am today, maybe. Starting in ’57 with Sputnik, suddenly your country wanted you to become an engineer or something like that. In the town that I lived in, the technically-inclined classmates all wanted to go to Lehigh University and get engineering degrees and go to work for the steel company. So that was a background, I was a little bit of an outlier from that, but it was somehow respectable, an expected career to think of technical things, you know, to own a slide rule and maybe a voltmeter.
I got interested in radio for a while. I would read the radio magazines, one of which, called CQ, had my initials. QST was another one. We had a good public library. I devoured all the technical books there, even though they were from the 30s and out of date. My uncle (my mother’s sister’s husband) was a physician, internal medicine. Very curious about science. He owned all of the Mr. Tompkins books [by George Gamow] and I got to look at those. He was a space groupie before that was a thing. And he had been an undergraduate at Lehigh so occasionally he would take me to public lectures there by scientists, mostly astronomers ’cause that was his thing. I was connected with that world a little bit from early times.
Chris, how big of an influence was religion in your upbringing?
[Laughs] I was raised in the Episcopal Church, the Cathedral Church of the Nativity. I loved the language of the liturgy, the Book of Common Prayer, the King James Bible. My parents were pretty religious. I guess I was fascinated by the spectacle more than anything. I don’t know that I was ever a sincere believer, but I went through all the forms.
I had an epiphany. I was the senior altar boy or something like that. The bishop would come to church on feast days and one day — the size of the church was known — one day unaccountably he prepared [consecrated], I would say, three or four times as much wine as was necessary for the communion and an equivalent oversupply of [communion] wafers. And of course you can’t leave that around after you’ve served the congregation. So he consumed all the wine and left it to me, without any liquid assistance, to consume all the wafers. This was a crisis of my faith, I would say. I decided that either I would become the Archbishop of Canterbury or that was it for me. [Laughs]
Anyway, so I think it was formative in terms of language and literature, respect for language. I respect religious people. I know what it does for them, but it’s not part of my life.
Did you go to public schools throughout?
I did, yes. It was a large public high school, I had about 800 classmates. And the whole range from vocational training, secretarial, business training, up through college prep. Good teachers, some of whom were still around from my parents’ time when they had gone through the same school, so they were pretty senior by that time. And, you know, it was backward in the sense that many people of my generation — people I met in college — had been through PSSC physics. That had started in the late 50s, and then by the time we were in high school, it was available to many people. We didn’t have any of that. I think my physics textbook was some falling apart red book from the 1930s.
And no calculus in my high school. The teachers were devoted people who taught what they taught rather well, but were not pushing the envelope as far as content was concerned. Probably the most remarkable was our German teacher. Looking back, it’s sort of remarkable to me that German was an allowed language ’cause people still had the memory of the war.
But there was this wonderful woman, Fräulein Muriel Wilson, again, from my parents’ vintage, she had been teaching there when they were in high school, and she was a wonderful teacher. Including the normal classes and summer school classes, I had five or six years of German by the time I got out of high school. For the advanced kids, she’d have us read Faust I and Faust II. I understood all the words. I didn’t understand the life experiences, of course. Just as in Shakespeare when you’re in high school, you have no idea what life is really about. Scientific German, things like that. So that was extraordinary. That was off scale compared to any school. The rest was, as I say, devoted teachers, but not exceptional content.
Chris, either by aptitude or interest, were you a standout student in math and science and you knew when you were thinking about college that it was math and science that you wanted to pursue?
Those were things I could do, yes. And so I was interested in that. I was lucky not to have — I mean, many people talk about having a terrible physics teacher, I did not have a terrible physics teacher. I had a good physics teacher who believed in laboratory exercises rather than book learning and was curious about things and encouraged us to be curious about things. Nathan Auerbach was his name. Good man. And I, early on, made a distinction between physics and engineering, which was misguided, but you need to be misguided to do things. I was convinced that physicists got to make the laws of nature and engineers applied them and I wanted to make them.
You had a God complex.
Something like that. It’s partly true, of course. Anyway, as I said, lots of my classmates wanted to be engineers. I decided that I wanted to be a physicist, whatever that was.
Given your father’s profession, I’m curious if his advice or his influence was part of your decision-making.
As I say, he was not very specific, but he gave strong encouragement for me to follow my ideas. You know, when I was applying to college, there was one place Cornell, that had an engineering physics program, he never pushed me in that direction. I was on my own pretty much. One good thing was that, you know, I was fine as a student. Every now and then, every few years, teachers would want me to skip a grade and my parents had the good sense to realize that that’s not a good idea. And kept me where I was. So I did things that were outside the classroom if I needed more stimulation. Of course I wanted to be a jock, like everybody. That was not to be, although I did become a very serious tennis player.
What schools did you apply to when you were thinking about college?
So it’s kind of insane. Cornell was my safety school and I applied beyond that to Harvard, Princeton, and Yale.
Cornell was your safety school?
Yeah. As I say, I was — what did I know? [Cornell gave early notification, so I knew that I could count on it.]
Did you graduate at the top of your class? Did you have grades to support this ambition?
I was pretty close to the top of my class. I think I must not have been first because then I would remember. You know, all grades were worth the same and there were lots of smart kids, but you could get equal credit for a course in analytic geometry and for one in typing. I think I must have gotten a B in art or something like that. So I couldn’t have been quite at the top of my class, but I did fine. I did fine.
And why did you choose Yale?
Well, I was on the waiting list at Harvard and I was rejected by Princeton. Princeton, instead of me, took — our school was not a feeder school for these Ivy League institutions, so Princeton took one of my classmates, a great guy named Don Rodenbach who was, in addition to being a fine student, an extraordinary basketball player and for the next couple years threw very good passes to Bill Bradley. So I think Princeton did just fine by making that choice and Don did fine as well.
I’d been fascinated by Yale. I was put off by the interviewer from Harvard (where I was on the waiting list anyway). So it was between Yale and Cornell and Yale, for who knows what reason, seemed more appealing to me. When I’d gone to visit the campus, I was taken with it. And it turned out — you don’t know about the branches you don’t take, but it turned out to be an extraordinarily good path for me to take.
And were you thinking physics right from the beginning or you were still on that line with engineering and physics?
No, I was thinking about physics without really understanding what it was. During my first year at Yale, I was much taken with — we had wonderful introductory courses and one that I particularly enjoyed was in economics taught by… it seemed that the President’s whole team of economic advisors came from the Yale faculty and they would entertain the freshmen. I was quite taken with the mathematical side of economics as introduced in Paul Samuelson’s book. They don’t have experiments in the same sense that we do in physics, but that was something that I saw as a possible alternative.
Did you declare the major in physics right away or that came later on?
We didn’t really have to formally do it, but it was my intention at that point. And I think in my second year, there were some problems that had to do with circular motion, and on a Sunday afternoon I decided that if I could actually figure them out, I would be a physicist, and if not, then maybe something else would look good to me. Luckily, I finished the problem set. Well, how do I know? My life might have been great in the other direction as well. Anyway, I did master the problem set, and so physics was it from that point.
Chris, what was the culture in the program? The undergraduate department. Were undergraduates in a position to develop relationships with professors or was that sort of out of the question?
It was by no means out of the question. The timing depended on various things. I had a scholarship and as a scholarship student, you had to do some work, ten hours a week. The first year was serving food in a dining hall, so I actually got to meet a lot of graduate students because I was slopping food onto their plates in the Hall of Graduate Studies.
In the second and third year, I had a position in a computer lab run by a nice man called Conrad Wogrin, and I think he went off later, ten years later or something, after having been a full professor at Yale for a decade or more, went off to UMass to establish some big program there. During the time that I was working for him, I was sort of in charge of analog computers. I got to work with patch panels to program them and I became pretty good with a wire wrap tool. I don’t know if you even know what a wire wrap tool is these days. [Laughs]
I do not.
It was this pistol-shaped tool that you would squeeze and a thin barrel would spin and wrap wires around a terminal. So that was fun. I got to meet his graduate students and he would spend some time with me. Transistors were new at that time. I mean, they had been invented 15 years before, but nobody had ever touched a transistor. So I got to play with some transistors and try to make logic circuits out of them. I annealed a lot of transistors both there and in electronics lab in my physics courses. So that was good.
Within the physics department, I have to say it was a really supportive atmosphere. Not cutthroat among the students. I mean we’re all trying to do our best, but there was no subversion or anything like that. And I gave a talk, now, three decades ago at a Yale reunion of graduate students, for which I was the only undergraduate invited back because I was working on the SSC project at that time. Being puckish, when I was introduced by Allan Bromley, the President’s Science Advisor, I said that one of the wonderful things about being an undergraduate physics major at Yale was that the faculty took us almost as seriously as they took themselves. And nobody laughed. [Laughs] Maybe it would have been more diplomatic to say that they took us almost as seriously as we took ourselves, which was also true!
Anyway, the professors were indeed very supportive. We got to spend time with them. We got to meet graduate students who were often our lab instructors or the graders in our courses and so on. And a number of my classmates who were really directed toward experimental physics got positions early on in some of the accelerator labs at Yale. I would hang out with them and meet the graduate students and meet the professors there, even though I wasn’t working with them at the time.
I did a senior thesis with a very good nuclear theorist called Itzhak Kelson, and so I got to know him and the people around him [Gerry Garvey, for example]. And I do remember from an early time some of the people on the faculty — some of the theorists were hockey fans and I couldn’t go to all the hockey games, we got free tickets to the hockey games. I couldn’t go to all of them, I had homework to do. So I ended up giving some of my hockey tickets to the professors and getting to know them that way. You know, it was that kind of a place where the faculty were very professional but still very available to undergraduates.
Chris, in terms of your exposure to physics, did you have an idea by the time you graduated what kind of physics you wanted to pursue for graduate school?
Kind of. Originally, I really wanted to do experiments, but I thought the right way to do experiments was to be like Fermi. This was kind of delusional. Have a total mastery of theory and yet do experiments. And so that was one aspect. I was very drawn to the big machines, to the big accelerators.
I remember one early influence — of course we were reading Scientific American and stuff like that. Eventually I started going to colloquia and theory seminars at Yale — but the New York Times was our main source of scientific culture or scientific breakthroughs. That’s where we got to learn about the cosmic microwave background. I re-read some of those articles recently in connection with the book we’re working on and they were pretty muddled, but they were exciting anyway.
One of the things that I read was a report of a Washington APS [American Physical Society April] meeting talk by somebody I came to know later, Karl Berkelman, about the first colliding beams experiment at Stanford. Physicists were colliding electron beams with electron beams (at 300 MeV per beam) and they registered one interaction every 15 or 20 minutes compared to the 10 billion a second that we get now in our colliders.
So I thought that was pretty fascinating because the article explained well enough that hitting an oncoming target was much better than hitting a stationary target. You could effectively go to much higher energies. And then — and I’ve not been able to recover this source, it wasn’t in the Times — shortly after that, I came to understand, maybe it was in a talk, that they were going to do this experiment and they didn’t know what would happen. And I thought that was fantastic. You know, the answer was not in the back of the book. It was very important that the way it was phrased was they didn’t know what would happen rather than they had no idea what they were doing or they were testing quantum electrodynamics, which is, after all, what they were doing.
So I just thought that that was fantastic stuff and maybe I should be part of it. Yeah. So that was — by the time I finished, that was the direction that I thought I was going in. But I have to say I wasn’t sure what I wanted to do, and so when I got around to applying to graduate schools, one of the notions was I should go to a place where there were many excellent research lines. Then if I changed my mind or if I got attracted to something else — I wouldn’t be locked into something.
Did you have a senior thesis?
Yeah, I did. Let me say a little bit about the undergraduate education before then. As I said, I was sort of impoverished compared to my classmates in terms of calculus and PSSC Physics, so I had to do a little catching up. The first course that was really decisive for me was the one I took during my second year given by a man called Robert Beringer. I now recognize this was sort of a standard, modernized American version of the old German course in theoretical physics. So it was a bit of everything. He was a great teacher. And you just learned in that class that if you learned to think, you could address any problem, something you better learn if you’re gonna be a physicist. So that’s where I learned it, in Robert Beringer’s class.
And then through the rest of it, there were really high quality classes in a number of things. Robert Krotkov, who came from Dicke’s team at Princeton, introduced me to quantum mechanics. We had “cultural” interests, Henry Margenau was a professor. He would teach not only mechanics, but the entire history of mechanics from antiquity to the present time. It was a really broad education. I did my senior thesis with Itzhak Kelson. It was on the shell model of nuclear structure, shortly after Mayer and Jensen had gotten their Nobel Prize, so I got to read Maria Goeppert Mayer’s book. I think my problem amounted in the end to diagonalizing a 32 by 32 matrix, for configuration mixing for states between sulfur 32 and calcium 40 on a Marchant calculator, so basically by hand. If I were masochistic, I could redo this with a couple lines of Python and find out what fraction of the entries were actually correct, but I’m not gonna do that.
But I learned a lot from that and Itzhak encouraged me very early in that year to start going to theory seminars. The first one I remember was given by Gary Feinberg from Colombia. Gary was working on tachyons at that time. Now, he was kind of a funny guy. And I remember that everybody was laughing all through the seminar, and because of his manner, it wasn’t clear whether they were laughing at this idea of faster than light particles or were laughing with him. But it did occur to me that these people are having a really good time and maybe I should spend more time with them. So that was, in a queer way, influential to me.
So I went to Berkeley, as I say, I was thinking I would do experiments. I would learn something about these big accelerators.
And Chris, was your sense that Berkeley was the place to be for the kind of physics that you wanted to do?
I think so. I was trying to remember which places I had applied to, and I actually can’t. I applied to Berkeley and Stanford and Chicago, I remember. There must have been one or two more. I think I didn’t apply to Princeton because I thought it was too narrow. It’s a great place, it would have been fine if they had taken me. Anyway, I can’t remember any other places. There was, at the time — well I had had for a couple of years a girlfriend who came from Alameda, California, and who regaled me with tales of the golden state and the wonders of Berkeley and all of that. By the time it came time to apply to graduate school, we had broken up, but she had gotten inside my head and so the idea that as an east coast kid I would go west, somehow was an influence.
And then the legend of Lawrence and his laboratory was very strong. Berkeley was a powerful place. You know, when I was a little boy, they had discovered the anti-proton, they had bubble chambers and things like that. It just seemed right. Somehow even though Stanford’s a terrific place and even was at that moment, probably it wouldn’t have been as interesting as Berkeley until a little bit later.
You mean in terms of how far along SLAC was at that point?
Yes, SLAC was just coming into being at that time.
Anyway, Berkeley was the place. I got accepted early at Berkeley because they did rolling admissions and I withdrew my applications from the other places. I just had decided that was where I was gonna go.
And was there a particular professor you wanted to work with or you developed that when you got on campus?
There was not. So I was — you know so little as an undergraduate. You know, you’re influenced by your professors and your peers. Your professors know what graduate schools were like when they were graduate students. There’s a time lag. I’m seeing that in a couple of places that I know like Santa Barbara, which 15, 20 years ago became great, but nobody knew it yet. And so there was a lag before they started attracting really good students.
Anyway, I had incomplete information, but in the end, the decision turned out to be quite fine.
Chris, I wanna ask you, coming from Yale in the mid-1960s, a relatively culturally conservative place, and then you get to Berkeley later 1960s and it’s Berkeley. So my first question is what were your impressions from a sociological perspective when you arrived on campus?
[Yale was not inert. In particular, there was a lively movement called Americans for Reappraisal of Far-Eastern Policy, led by William Sloane Coffin.] The Free Speech Movement had happened at Berkeley, but that wasn’t an immediate influence. Opposition to the Vietnam War built over the next two years.
Let me take a minute to talk about how I got there in the summer. I was offered a summer job at Livermore, at which I’m slightly aghast now, although I guess one can make the argument, you might even believe it sometimes, that we produce these weapons so we’ll never have to use them. Anyway, they offered me a job. They moved me across the country with my possessions. There were nice people who gave me time to devour Feynman’s books on QED and the Theory of Fundamental Processes. So I learned to do Feynman diagrams. I didn’t understand everything about them, but I could do the arithmetic really well. And I even did some little problems and eventually published a couple of little papers on plasma physics there.
And very important was that I met my future wife there. She had graduated from Wellesley and had taken a job as a junior physicist at Livermore. There were no real east-coast-caliber newspapers in the Bay Area. The New York Times didn’t exist on the west coast yet, but The Wall Street Journal did. So I was sitting in the cafeteria reading The Wall Street Journal for news. She claimed to believe that I was somebody she had known from MIT. And so that was a good thing, you know, all the chagrin of being associated with a weapons program, however briefly, goes away because that was a strong influence on my life.
The next thing that happened was just before classes started, Berkeley had the International Conference on High Energy Physics on campus. It was much less regimented in those days. So for a few dollars a day I think, any street person or incoming graduate student could get a day ticket and sit in the back of the room and listen to the talks. Today, there are huge registration fees and sometimes you have to pass through a security guard to go in and so on. Anyway, anybody with a few dollars could go in and so that was fascinating to me because I got to see some of these great people that I had heard of but I had never seen before.
To my delight, I could understand some of the talks. Dick Dalitz gave a talk on the quark model; he was one of the early true believers, and he was very — he explained physics in very simple terms, as I got to know later on, so that was good. I could understand that and didn’t feel completely intimidated. Murray Gell-Mann gave a talk, of which I understood parts — a funny talk, as I look back at it.
And the thing that impressed me the most, sitting in these sessions — remember I knew nothing — was that these great people, famous people, were not talking about deep principles and the Theory of the Universe and all of that. They were talking about individual phenomena; I now recognize this attachment to little facts that you put together to make a big understanding goes back to Galileo. But I saw it in these people: that they could be concerned with, not trivia, but little specific facts, and focus on them and try to learn something from them. So I think that influenced my outlook.
Anyway, then we started graduate school. Berkeley was very big at the time, ambitious. They were building toward 500 graduate students in physics, so it was a huge program. Lots of great people. The courses were extraordinary. Gene Commins, who was the mentor of many superb physicists, gave the course on quantum mechanics. Gene was one of these brilliant atomic physicists who not only could do everything with his fingers, but could manipulate atoms and their levels in various ways. So he was a great teacher.
Dave Judd, who was an accelerator physicist at the radiation lab, gave a three quarter sequence on mechanics leading up to hard nonlinear problems in accelerator science. I took a course in general relativity from Eyvind Wichmann in my first year ’cause that’s what you have to do to be a real scientist, it seemed to me. Plus E&M and so on. So that was it for the first year.
I had a summer job at Livermore again. You know, my experimental colleagues were already at the Rad Lab. Somehow Berkeley was guiding me toward theory but I have to say, if I had met, in my first year or two, George Trilling or another great experimenter, I could easily have gone in that direction.
Yeah. George recently passed.
He did. And anyway, so I was still open to which way I was going. I had something called a theory fellowship, but I wasn’t that serious about it yet.
Chris, if you could narrow down all of the exciting things that were happening, both in the department and in physics generally at that time, what were some of those things and what were most exciting to you personally?
This was in 1966 to ’67, the first year. Particle physics was kind of dull in the sense that people were finding lots of particles in bubble chambers, but didn’t really know what to make of them. So it was kind of fortunate that in spite of this dullness, sort of lull in the field, I had the good wisdom to decide to do that. The decisive influence came in my second year when I met Dave Jackson. Geoff Chew was of course the big influential figure at Berkeley at that time in particle theory. Geoff went on leave in the fall of ’67, for that academic year. So he wasn’t going to be teaching his course, which some wags called Deuteronomy and Revelations.
Another big presence had been Steve Weinberg. He left also in ’67. I think he was first at MIT, then at Harvard, and then — his wife was going to law school, so he was off in Cambridge. Steve is somebody who had been pointed out to me as a god. So he wasn’t there. And so with some disappointment, I was going to take the course called Dynamics of Strong Interactions taught by J. D. Jackson. Of course, having labored through Classical Electrodynamics, I assumed that he was somebody who had been dead for a hundred years. [Laughs] A little man with lightning coming out of his ears. But he wasn’t. And he was probably a young man at the time. [He was all of 42!]
So he was a great teacher. He gave a wonderful course on the dynamics of strong interactions and all sorts of things. Meticulous preparation. I found that we shared some personality defects. I always did my homework problems in ink with a fountain pen, which meant some of them had to be recopied multiple times. And I learned that he was — well, he took all of his notes with a black fountain pen. And so as I say, there was this cultural affinity or personality defect, that might have linked us, or might have been what sort of attracted me to him. Anyway, he gave a wonderful course.
I was taking other courses at the time, including some on experimental analysis. Chuck Zemach gave such a course for the experimental students. I mean one of the great things about Berkeley is that we all seemed to take all sorts of courses. During that year, Eyvind Wichmann gave a three quarter course on quantum field theory. All the theorists signed up for that, but all the experimenters went to it anyway. He started with Pontryagin’s book on topological groups and ended with renormalization theory. Offset by a quarter, Stanley Mandelstam, another wonderful teacher gave a course on Lagrangian field theory. Stanley’s course was the so-called “easy one” that the experimenters signed up for and the theorists sat through. So we were being exposed to a lot of stuff.
And after the semester, I approached Dave and asked him to give me a warm-up problem, a test problem, which he did. And we bonded at that point.
What was the problem?
The test problem was a little calculation on eta decay to two muons or K-long to two muons equivalently. It was supposed to be a background calculation for some experiments that were being done at the Bevatron. So we did a nice job on that. And as it happened, there was an experiment done, it was the thesis experiment of one of my classmates, Henry Frisch, which did not find the minimum amount, minimum rate that you should have found, that, by God, you had to find. And because of Henry’s wrong experiment, our paper became very famous in a small, small circle — as did Henry. So people started paying attention to me, thanks to Henry. Henry is shameless. He says, “Fame is irreversible.” [Laughs]
Anyway, so Dave and I got together. We did a few more problems during the next year, and spent a lot of time together. I learned a great deal from him. In the environment, which was LBL [Lawrence Radiation Laboratory, at the time], Geoff had — he would have six or eight students at a time. You know, this is a guy with many ideas and a great force of personality, and he could take care of all of these students. He attracted a lot of really good people. Stanley would have a student or two and then some of the younger faculty members each might have had a student. We took our classes on campus, but the lab was the hub of the activity.
Geoff ran something called The Secret Seminar, which I learned later was modeled on a Fermi seminar in Chicago, and so the topic wasn’t announced, the speaker wasn’t announced, you would just go. And that was wonderful because nobody would stay home because they didn’t like the subject. We all were exposed to things.
There was also, at that time, in Berkeley, generally a great culture. Everybody in the department would go to the department colloquia. And I remember many of them being just brilliantly given in the sense that somebody would come in and state a problem and then explain the solution to the problem, theoretical or experimental, in terms that a first-year graduate student could understand. You know, wonderful, broad education. I’ve been in some places where faculty members don’t set the example of going and so their post-docs and students don’t go. Berkeley, at that time, was very different. It was a place where the scientific culture was available to everybody and everybody was drinking it in.
What was the process for you developing your dissertation?
[Laughs] Dave went on leave in ’69 to ’70. We had worked together for one and a half years. He went on leave to Cambridge, England, to do his second edition of Classical Electrodynamics. By that time, he had me as a student, Bob Cahn coming on, and Rick Field was about to be accepted, I think. And he didn’t take us with him. I thought this was a great indignity.
You would have gone?
I had never been out of the country, of course I would have gone! But in fact, he did me a great favor. We were adopted — I mean, Geoff was our caretaker. We became part of his circle of students, even though we were working on whatever we were working on. So we were by no means abandoned. And the great favor that Dave did for me, consciously or not — he was pretty crafty so it might have been conscious — I was already pretty much of a grownup, but I didn’t know it. And with him gone, I had to realize that I was a grownup.
The experimenters at LBL would come around and they would talk to me — because they couldn’t talk to Dave, they’d come and talk to me, which meant I had to produce. I had to give answers or think through problems. And so I realized, I mean, you’re still a little student, you know but barely anything, but I realized that I could do this stuff and that people were counting on me to do it. And it might have taken much longer if the great man had been there at the time.
The story of my thesis was typically Jacksonian. He had said when he went off to Cambridge, “You know, you’ve done a lot of different things.” I guess I had written a dozen papers or so on various things by that time. He said, “We’ll just staple the papers together and call it a thesis and when I get back I’ll make some phone calls and get you a job someplace. So don’t bother me.” Basically.
Luckily for me, and this is really providential, one of those summers, Fred Goldhaber from Stony Brook, who had been at Berkeley before, was back at Berkeley and his uncle Gerson had an interesting effect in one of his [bubble-chamber] experiments. They found a narrow dip in the rho meson resonance. So a clear interference between the rho and omega mesons — an isospin-violating effect. And with Fred and Geoffrey Fox, a post-doc at the time, who went on to a stupendous career in computer science after some time doing particle physics at Caltech, we figured it all out. We made predictions about different reactions. In particular, one night I was alone in the laboratory and I realized that there was a problem that the meson spectroscopists were agonizing about. This shows how microscopic the problems were at the time.
The rho resonance was, I don’t know, 150 MeV wide in hadronic experiments, and in the just beginning electron–positron experiments in France and in Italy, Rome and Paris, it was only 120 MeV wide. So this was terribly mysterious, obviously terribly profound. And using what we had done, I realized that in this particular reaction, there would be constructive interference below the omega mass and destructive above. I made a plot and it gave a nearly vertical line on the high side that made the rho peak seem 120 MeV wide and I understood this before anybody else in the universe. So that was fantastic.
Well, a pretty minor contribution, although it became cited by the Particle Data Group, so what more posterity could you want? Anyway, because of the work with Fred, he decided that I could do some things. And during that autumn, he called me up and said, “If you’ll send an application to Stony Brook, you can have a job.” So I sent my application to Stony Brook and I asked Dave for a letter, which he grudgingly gave because it wasn’t part of his plan. I think it must have been an extravagant letter because after I got the job, he told me how deeply mortgaged I was and I’d better not screw up.
What was his plan?
You know, I suspect it was to send me to SLAC the next year, which wouldn’t have been so bad at all.
Right. Was part of the attraction to Stony Brook — was Brookhaven part of the equation for you?
Brookhaven was part of it, but it was also that it was — among universities — it was a terrific place. C. N. Yang was there as the founder of the theory group, the Institute for Theoretical Physics. They had a theory faculty of about a dozen people — good people — which was nearly unheard of in a university group. You know, there were only a few places like that. I knew Fred, I knew some of the other people. When I got there, there was Yang, there was Ben Lee, in nuclear physics there was Gerry Brown, Bill Weisberger was there, just numbers of wonderful people. And the university was in start-up mode. Johnny Toll was president, he paid attention to postdocs and the department was welcoming.
So it was a great place. [Nelson Rockefeller wanted to make it the Berkeley of the East.]
And you knew this by reputation or you only appreciated what a powerhouse it was once you arrived?
I knew it vaguely before I went, but then I really appreciated that I had found a wonderful situation. In fact, it got more and more wonderful. So yeah, that was a piece of luck. You asked about my thesis, that’s where we got started on this. Dave had told me this line that we would just staple my papers together. Once I got the job, he said, “Well, now you have to write a real thesis.” I decided to do something different. Regge poles were a big thing then and two-Reggeon exchanges were becoming a thing. So I decided just to broaden my education. I do remember writing to him and saying, “Well, I guess I should do something relativistic and mathematical.” You know, again, totally naïve.
I did write a very thick thesis on two-Reggeon exchange reactions. And he made his way back from Cambridge — he had been at a summer conference somewhere, Kiev maybe — he arrived back jetlagged. We were thrown out of our apartment because the new term was about to begin and the landlord wanted to rent it to somebody for the next school year. We were taken in by some nice lady in the apartment building. Dave was very meticulous about proofreading and so on — he had standards — and he couldn’t find the time to actually thumb through this huge document.
I had had some surgery that summer, I was damaged goods a little bit. We came to his office when he got back and my wife said to him, “When are you gonna let us out of this place?” [Laughs] And so he decided he would read the thesis and we were given permission to drive across the country to Stony Brook.
Chris, I’m curious —
Anyway, it wasn’t the main line of work, it’s sort of an embarrassing title, but I overcame these humble beginnings.
I’m curious, Chris, at this time when you got to Stony Brook, were you paying attention to all of the excitement around string theory that was going on?
This was in 1970. Part of my Berkeley education had been that I had somehow understood that SLAC was on the other side of the Bay and that they held colloquia in the evening. I would drive over sometimes to hear Feynman or Bjorken talk about the parton model and the new experimental results from there. I was up on that. [Goes silent]
Uh oh, we cut out Chris. I don’t know if you can hear me, it’s frozen. Let’s see if we can pick back up.
[Quiet for technical difficulties]
There you are.
I’m back, sorry.
So I was saying I was aware of the deep inelastic scattering results from SLAC. Geoff had gone off in 1968 to the Vienna Conference and he came back, not with news of the SLAC discovery [presented there], but with the news of this marvelous formula discovered by Gabriele Veneziano, which was the Beta function. And this was Geoff’s dream. Analyticity, unitarity, crossing, all these things making the theory of the universe. You know, at that time, all of us owned all these books about special functions, we were into that stuff. Jackson was a maven of the orthogonal polynomials; he would say that he’d been born a century too late for the real action. I still own, to this day, all the volumes of the Bateman Manuscript Project and other tomes. So we’re all looking at the Beta function and generalizations and things like that.
And the very beginnings of string theory started to emerge, partly at Berkeley. Stanley was involved in that, Joel Shapiro, a few other people, in which they began to sew amplitudes together and learned that there were strings and things like that. So I was paying attention to that. Some of my contemporaries in graduate school were doing that. I knew it was going on, but it was not a total sensation, and certainly in the form in which we now know string theory — it didn’t exist yet. That came much later, around 1984.
So yeah. I knew it at some level. I probably knew more about it than most people at Stony Brook did at the time, but in a version that wasn’t what it grew up to be.
Right. When you got to Stony Brook, did you see this as an opportunity to continue to refine your dissertation or did you wanna take on new projects at that point?
I’ve always been curious about new things and I think one of the things that has been fortunate for me is that I respond well to stimulation of various sorts, a lot of it experimental stimulation, some of it the stimulation of theoretical ideas. So of course I did write up my thesis, there were a few papers and some applications from that. But I never saw that as a life work.
To my great good fortune, among the many interesting people at Stony Brook at that time — Yang always attracted some wonderful visitors — there was a person from Oxford called Chan Hong-Mo, very good guy. He later got diverted into string theory in a big way with Jack Paton and other people, but at the time, he was very phenomenological. Al Mueller, who was at Brookhaven, had just invented his analysis of inclusive reactions. I knew a little bit about the idea of inclusive reactions from Feynman and Geoff’s students at Berkeley, including Carleton DeTar. Yang had his own ideas about these called limiting fragmentation. And so with Chan and two other young people, we applied Al’s ideas in a paper that turned out to put things in a form where experimenters — even at those low energies — could respond to them and we could begin to do analyses that would tell us something. So that was a real generalization of what I had done in the past and, you know, got me noticed.
Hong-Mo was a great guy to work with, a bit older and therefore more mature and with experience. And I worked with other people at Stony Brook and we used the computers at Brookhaven, so I got to meet people there, became aware of the experiments there. [My Stony Brook colleagues were collaborating on experiments there.] And in my first year, just after Christmas, I think the department must have been responding to some rumor that I didn’t know about, Yang came to me and said I was on the faculty. So I was made an assistant professor after, I don’t know, five months or something like that.
And this was a total surprise, this was not sort of baked into the original agreement of your postdoc?
Right. Total surprise. It had nothing to do with the original agreement and certainly I was not mounting a campaign for anything like this, you know, I was just having fun learning about physics and doing new things. So that was — and now that I’ve hired and promoted many people myself, I think back and say, you know, “What conceivable paper case was there for this?” Well, luckily it didn’t turn out to be a complete embarrassment for everyone concerned.
So that was great, and that was one example of Stony Brook being really good to me, but good to a lot of young people. An immensely supportive place. You know, we were encouraged to go around and do things.
Chris, did you immediately — when you joined the faculty — did you immediately start teaching and taking on graduate students?
Not until the next year when it really took effect. In that summer, there was a conference in Dubna, in Russia, that Yang didn’t want to go to but felt he couldn’t snub, so he sent me. So I got to do my first — I left the country for the first time. Got to see Mother Russia. Met Volodya Gribov who was a great hero from my Berkeley days, of course. Bruno Pontecorvo, Lev Okun in Moscow and so on. So that was pretty terrific, you know, to be sent on a junket like that. I think I spent —
Chris, did you get the sense that you were being trailed at all when you were in Russia?
It was hard to notice. It was hard to notice, I would say. [I wouldn’t be surprised.]
It would not have been out of the question, given the sensitivity of all the issues involved.
No, that’s right. That’s right. I did create a minor scandal the first day of the conference. Gribov, the great Gribov, came to me and said, “Next session is all Commissars, you don’t go. Come with us.” So he invited me to go swimming in the Volga with himself and Pontecorvo. And what did I know? I went back to the hotel room and I put on my little, tiny, microscopic Speedo swimming suit and threw a towel over my shoulder and walked down to the hotel lobby, where I was immediately surrounded by the entire hotel staff.
I had no idea that Russians were that modest. It turns out they have some technique for getting in the water first and then taking their clothes off. Gribov and Pontecorvo were enjoying this immensely. I don’t know whether they set me up or I just fell into it. Anyway, that was terrific.
Russia, at that time, was monochrome, totally grey. After some adventure at the airport that led the Air France pilot to treat us to a bottle of Champagne in flight, we flew out to Paris and were met by a friend. I remember driving out of Orly seeing a Cinzano poster in pink and magenta and purple and thinking, “This is wonderful.” So I fell in love with Paris because of the grayness of Moscow.
I got to visit Orsay and a little bit of CERN at that time and then I spent, I don’t know, four or six weeks at the Rutherford Lab and then back to the US. We only had to teach one course per year as members of the Institute for Theoretical Physics, but I taught mathematical methods in the fall of 1971 and then gave a special-topics course on high-energy collisions in the spring so I could get to know more students.
When did you start taking on graduate students?
Soon thereafter. I had two graduate students at Stony Brook. The first one was Deepinder Sidhu who did a nice thesis on improved Glauber corrections for deuteron scattering and so on. He had for a decade a career in particle physics and then became a computer scientist and got a nice faculty position because of that.
And then the second student who worked with me on aspects of inclusive reactions was Alex Chao, now a very famous accelerator physicist, Wilson Prize winner, things like that. So he did some nice work with me. Alex was influenced — and then it got to the point where I was leaving for Fermilab — so Alex was very interesting because he’s a brilliant man. He was troubled, it seemed to me — I should discuss this with him sometime — he seemed troubled by what we have to do in theoretical physics. You can’t solve the problem you want, so you have to lobotomize it a little bit, simplify it so it’s a problem you can do. And the art of course is in capturing the essence of the problem when you do that.
So he liked the idea of things that were well-defined. Frank Yang had just come back from maybe his second visit to China, preaching the doctrine of Serve the People, so Alex was much taken by that. And when I went off to Fermilab, he started working with Ernest Courant at Brookhaven on accelerator physics. Ernest is somebody I had known because he had taught at Yale. He would fly over to New Haven and give a course on mathematical physics for the graduate students that a few of us took. Wonderful man, one of the inventors of strong focusing. You know, there’s a guy who should have had a Nobel Prize. Anyway, by the time Alex realized that all accelerator magnets have fabrication errors in them, and therefore the problem is not completely well-posed, he was already such an accelerator genius that he got over whatever emotional hang-up I imputed to him.
So those were my two students, good people to be exposed to. I enjoyed having both of them. One at a time was about what I could take.
And how much of your time day-to-day did you spend at Brookhaven?
It depended. In the summers, there were summer studies there that I participated in. That was something I enjoyed. Often, I would drive over at night to use their CDC 6600 [mainframe]. At a certain moment, I remember — this was another example of C. N. Yang being nice to me — he got me a dialup terminal [with an acoustic coupler] so I could use the Brookhaven computers from my office at Stony Brook at the rate of 110 baud, as we used to say in those days. You know, you’d type a character, sort of a quarter of a second later it would come back to you and so on. Well, that was wonderful, I didn’t have to drive over to Brookhaven at night to feed my cards in and so on. Anyway, I got to know the people at BNL. It was a benefit of being at Stony Brook.
And how much crossover was there between the theory that was happening at Brookhaven and at Stony Brook?
Well, Stony Brook, I think, was pretty broad. There were lots of people doing real weak interactions. Jack Smith was doing calculations for neutrino scattering and such things well before their time. I mean the energies were so low then. He was a student of Peter Higgs, and a very gifted man. Ben Lee was doing his chiral dynamics and weak interactions. There were people at Brookhaven who were experts in things called helicity amplitudes which I knew about from Berkeley. I think now there is a little more interchange — we had a few people from Brookhaven who were adjunct faculty members, Ernest Courant was, Marty Blume was in condensed matter physics. You know, I don’t remember anyone in particle physics. [Maybe Maurice Goldhaber, BNL Director, in an honorific role?] Sally Dawson is now, for example, and that gives Stony Brook the advantage of her presence.
Anyway, Brookhaven was there. I got to meet experimenters at Brookhaven. You know, we’d go to the program committee meetings and things like that. We tried to have joint seminars for a time. I worked a little bit with Ling Lie Wang [now Chau] who was at Brookhaven. We tried to have joint seminars. The distance was just a little too much and winter would come, there would be freezing rain or something and nobody would go. These things are always tough in the execution, even though they’re brilliant in the conception.
What were the circumstances leading to your move over to Fermilab? How did that come about?
So it came about in this way: the National Accelerator Laboratory, as it was called at that time, did not have a permanent theory group. It had a program in which some great figure, they were all men in those days, would lead the theory effort for a year and they started hiring postdocs. Partly because of the attraction of the new machine, which didn’t exist yet, partly because times were tough, they got some really good young people to come. And we had an agreement that Frank [Yang] signed that said it would be fine with Stony Brook if our people went to visit at NAL and Stony Brook would continue to pay the salary. Some expense agreement was worked out between the institutions.
I first went when that came into effect, I guess, in 1971–1972 when Sam Treiman was running the “theory year” program. I had a good time there. I guess I went for a week or something like that. You know, the machine was being built. Stony Brook was a campus under construction, so we had a lot of mud and dirt. Fermilab had a lot of mud and dirt at the same time, so it was very, very similar.
So that was my first exposure. Then the next year [1972–1973], Dave Jackson took over from Sam as the leader of the program, and he asked me to come for the fall semester. We went for the fall semester with our newborn son. And that was great because the machine was just coming on. There was this terrific pioneer spirit. Dave, I guess, was mostly there, but still commuting back to Berkeley sometimes, and there were great visitors. I got to meet John Bell for example and we even did some parallel work later on. Maurice Jacob was there. And this collection of young people that they got as postdocs. Dave and Marty Einhorn in particular invented the famous Wine and Cheese Seminar to bring people together. On Friday afternoon, everybody would show up there. The machine would run on the weekends. Everybody felt part of everything. It was a great environment. So I enjoyed that a lot.
The next year — I guess I must have gone back in the spring of 1973 a couple of times. The next year [1973–1974], Ben Lee took over as the temporary head of the group. And Ben asked me to come one week a month. This was fine with Yang. And that was fun, again, because I had my connections to the lab. I was doing things that were relevant to the bubble chamber experiments and to other things. Ben and Mary K. Gaillard and Jon Rosner were working on their famous “Search for Charm” paper. I would occasionally do dog work for them. I was sort of following what they were doing by doing a numerical integral or something like that that they couldn’t be bothered with.
So I wasn’t a real participant, but I was learning what they were doing, which was good because I hadn’t known about that yet. Ben was recruited then and decided, in early 1974, that he would be the founder of the permanent theory group. And he asked me to go along. I got this news when I was visiting in the winter. I remember getting to O’Hare and being stuck for five hours in a snowstorm. I arrived back to Long Island at 4:30 in the morning or something like that, came into the lab, the university, without having slept. And so I had just gotten the word that NAL would make me an offer. Frank had already gotten the word and he said, “I have something to talk to you about. You’re an associate professor.” [Laughs]
Just like that.
Just like that. Again, you know, what documentation do you need for these things? So I have to say, the lesson I’ve taken from this is when I’m considering a promotion or giving advice about promotions, if you’ve decided that somebody is gonna be able to do it, is ready, you don’t wait until the calendar says it’s time to promote them. You know, you don’t hold young people back, you just do it. And if you make a mistake, it’s your mistake, it’s not their mistake. And in fact, we don’t make many mistakes of that sort.
So that was the offer from Stony Brook. Then, being a theorist, I figured you can calculate your way through anything. You can figure out what’s the right thing to do, and I wasted months of my life trying to come to an objective decision. And finally I decided that I would take the jump. I loved Stony Brook. It had been — you know, the university was coming up. The colleagues were great. Nobody could have treated me better than they were treating me.
There were all sorts of opportunities, but in a certain sense, I knew who I would be having lunch with for the next 30 years, and although they were splendid people, that was a little scary to me. And then there was going to be this biggest machine in the world right outside my window at Fermilab. So I decided to do it.
Chris, was it a difficult decision walking away from academic life, to some degree, not in the research sense, but in the mentoring sense and in the calendar sense?
In all senses. So as you know, the great tradition of excellent theoretical physics in the United States is in the universities. The SLAC theory group was the one exception I could point to. Berkeley is so integrated with the campus, it didn’t count. So SLAC had been an example from my youth and gave me courage that we might be able to do something similar. And even though the psychological separation was pretty great at that time, they are near a campus, whereas we wouldn’t be. So that gave me hope that we could do something there.
But I loved teaching, I’ve taught for a long time, even after coming to Fermilab. And I do have moments, not infrequently, especially after all the universities switched to string theory, that maybe I could have done something for the world if I’d stayed in a university and had produced lots of students, lots of excellent students. There is, of course, a great deal of generalized teaching in the laboratory environment, plus the opportunity to mentor very fine postdocs.
Yeah, it was a real choice and you don’t get to know — as I’ve said before, you know how one path worked out, you don’t — so that was a real loss. It was a good place to live, further from New York than I would have liked, but still a good place to live. When I made my decision, Johnny Toll called me and he said, “Oh, you really shouldn’t — you’re breaking my heart.” Again, I knew I didn’t deserve this, but it’s still nice to get that attention from the university president. And he said, “Maybe you could be like Gerry Brown,” who at that time was spending half the year in Copenhagen and half at Stony Brook.
Well, I had a little kid, I had my first child who was a year and a half old at that time. It didn’t make sense to me to be running between two groups at the same time. And I convinced myself that if I was going to make a decision, it shouldn’t be on leave — that I should jump in and commit myself [so that I had to make it work]. That’s what I did.
So I should say, NAL matched the tenure offer, (lab tenure), matched the Stony Brook salary to the penny. There was no bidding war of any kind. It was all pretty civilized and everybody was good about it. I retained good relations with Frank and the rest of Stony Brook long after.
Chris, I’m curious if this move — did it mean that you would be joining an extant research group and joining that project or was this an opportunity to take a portfolio with you and set up shop in a new environment?
Well, Fermilab did have this collection of young postdocs, but no. I was going to be a free agent to do what I wanted. Interact with the experiments as I could. Bob Wilson — so Wilson and Ned Goldwasser were part of the recruiting and they had been wonderful people when I was visiting. And Wilson was very clear. He said, “I don’t want an institute for theoretical physics of people who are up in the sky. And I don’t want house theorists — people who just run Monte Carlo programs. I want superb theoretical physics that’s stimulated by experiments.” So that appealed to me a lot.
And when I first went — these things change rapidly — Ben was sort of the weak interactions guru and I was the strong interactions person. We melded our — I mean, we both grew and we melded our interests pretty quickly, but that was the idea, that I would deal with that side of the experiments and he would — as I say, it didn’t last that way very long, but I had my own channel to begin with.
And so what was that channel?
Among the early experiments at Fermilab were bubble chamber experiments. You know, there were these ideas of Yang and Feynman on multiple production, and Ken Wilson, in which I had become — because the field was so new — I was something of an expert. I gave the plenary talks at the DPF [APS Division of Particles and Fields] meetings in 1971, 1973, and 1975 on the subject, as a little kid. The bubble chamber experiments were a source of stimulation for me and the work that I and other people were doing — many people were doing — was a framework in which to analyze these first survey experiments that people were doing.
That was the beginning of things, but you know, then you were there. You got to know everything that’s happening and people come into your office with questions and so on. In fact, it didn’t take so long for the world to change. We arrived in the summer of ’74, the Lees and the Quiggs came in the same moving van from Stony Brook. The first thing that happened to me when I got there was [Wolfgang] Panofsky called me from SLAC and asked me to be on their Program Advisory Committee. So, a great honor for a little kid. I agreed to do that.
Their first meeting was in the fall. I was still unpacking and Pief [Panofsky] called me to say, “I know you’re busy and you’re just getting settled. This is a purely ceremonial meeting. We say goodbye to the old people, we say hello to the new people. If I were you, I wouldn’t come.” So I said, well, I was writing some paper that was stupendously important, I could stay at home and finish my stupid little paper.
The meeting I missed was the one at which the discovery of the J/psi was announced. I could have been there! Instead, I heard about it by telephone. So I told Pief I had learned two lessons from that. One was never trust a lab director and the second was to never miss another committee meeting. And nothing good ever came of that.
Anyway, so that was a thunderbolt, right. That was a largely unexpected discovery. In a sense, the idea that it was a charm/anti-charm bound state was obvious. The only question was, was it true? So Ben and Jon and Mary K. and therefore the rest of us were well prepared to think about that and contribute to it. I went to Caltech for a month in December of that year and then made a west coast trip up to SLAC for my really first PAC meeting, at which Ken Wilson and I tried to convince people what they should be doing to search for charm, and they had other ideas. So it took longer than we would have liked.
I stopped by Berkeley and I had a conversation with Geoff Chew. I’d been doing this great stuff [I thought] on multiple production. We were learning much more than I thought we could ever learn, and I said to Geoff, “You know, this was going better than I dreamed, and then the J/psi came and I was recalibrated.” And Geoff — in a response I should have been able to synthesize — said, “Oh, but you don’t understand,” in the kindest way possible. “First there were two quarks, then three, now four. Soon there will be an infinite number, and that’s the bootstrap.” He of course was not kidding. That was his worldview.
And in his funny worldview, he actually came around to his own rediscovery of gauge theories. He was a very impressive guy, even though he had this apparently religious fervor. Anyway, that changed everything. We started working on charm. Marty Einhorn and I did some work that we liked a lot on weak decays of charmed particles and we tried to push the discovery of that.
And Chris, to zoom out a little bit, with regard to this research, what were some of the broader, fundamental questions that were being asked around this research?
So what we had at that time was that in ’73, there was the discovery at CERN of weak neutral currents [in muon-neutrino–electron scattering], which indicated that everybody should take gauge theories of the weak and electromagnetic interactions very seriously. Ben, of course, was a great guru in that. We all learned the rest of it. I became pretty adept. And so the question was are those theories really true? Is the Weinberg-Salam theory or now Glashow-Weinberg-Salam theory the right implementation? Are there others? There were outlier experimental results from atomic physics that threw people off and gave model builders the chance to go wild and have a lot of fun making up all sorts of stories.
The next urgent thing, it seemed to me, became finding the gauge particles, the force particles, the W and Z bosons. And there were a number of ideas at Fermilab — it’s clear you needed higher energy. People talked about colliding the main ring on the booster, 8 GeV on 200 or 300, or making a proton-antiproton collider in the main ring or eventually in the Tevatron, and all sorts of stuff. A lot of them were nutty. Some of them were promising.
Alvin Tollestrup had a workshop on how you would get to high energy, at which we saw some of these ideas for the first time — not the experimental ideas, but the real practical accelerator physics ideas, like pbar-p with cooling and so on. And I decided that if people were making all these claims on what was the right way to do it, I should study the question.
And so I wrote a paper that later appeared in Reviews of Modern Physics on the production and detection of W and Z. That was how I really got into weak interactions. It looks primitive now, but it was pretty comprehensive for its time — and noted among other things, specific things that would happen if you had proton–antiproton collisions — charge asymmetries and things like that that became important when… That work helped guide the choice of what we did at Fermilab, which was to finish the Tevatron first and then be serious about a collider, rather than trying to rush and maybe win a race — probably lose a race — to the W with CERN. That gave me more connections with CERN, which was becoming my second home all along. My paper was used a lot in the design of the detectors that ultimately found the W and Z. I then had connections and grew up with some of the young people on those experiments.
So that was a big change for me — toward much higher energies and away from only particle production, but toward the weak and electromagnetic interactions. The other thing in the air at that time was quantum chromodynamics [specifically asymptotic freedom], which had been discovered in 1973. And at Fermilab, we had Bill Bardeen and company working that out.
Well, after I did the work on W and Z, I think I must have seemed sort of at sea. I mean it was a big chunk, I swallowed it, and I probably wasn’t doing anything visibly useful. So Ben came to me and he said, “You know, you should think about weak interactions at very high energies. Every theorist has to do it. It’s like the chickenpox. It’s better to get it over with while you’re young.” And so I started thinking about weak interactions at high energies and I had no idea what I was doing. I just started calculating things. There was a program at the time that one of Ben’s students [Satish Joglekar] had done, Chris Llewellyn Smith had done a piece of it, using S-matrix arguments to rederive the Weinberg-Salam Theory, the standard model of weak and electromagnetic interactions.
And so I started calculating things and found you could put things together. Hank Thacker, who was by that time with us, joined in — a superb calculator. He and I are totally outclassed by young people today but we were really good calculators once upon a time. What we could do seemed good. So we’re calculating all these things and we built up a theory and we did this and that. At a certain point, Ben noticed that we were having such fun covering blackboards with calculations and he joined us. A day came when it was clear that we had the answer on the blackboard. And we didn’t have any idea what the question was.
Bill Bardeen walked in with a preprint from Tini Veltman in which Tini had figured out from radiative corrections that you could place an experimental bound on the mass of the Higgs boson of around a TeV and we looked at our formulas and our formulas told us that from basic arguments of partial-wave unitarity you could derive an upper bound on the Higgs-boson mass. It’s right there.
It’s now become a famous argument because it’s so simple. You consider WW scattering at high energies and you can see that either you have a Higgs boson below a TeV or the theory goes crazy and there are lots of other interesting things happening. So that was fun. It influenced the choice of parameters for the SSC and the LHC and gave a way of thinking about what the role of the Higgs boson would be, beyond giving mass to the force particles and the fermions. It actually has a role in making the weak interactions behave.
And so at that point, I was now an expert on the weak interactions or at least becoming somebody who knew a little bit about the weak interactions. I went off to CERN very quickly. I was going to the Moriond Winter conferences. I stopped at CERN and gave a couple of talks, one of which was about the W and Z. I had a lot of consultations with people who were doing the design work for the UA1 and UA2 detectors. The other talk was about the bound on the Higgs boson mass. It was a good time.
Exciting indeed. It’s amazing.
Well, then it got more amazing. So in June of that year — I have to say, I did little things before then that struck me as quite wonderful, but my standards were low [laughs] — because we had these young people around, you know, you could have an idea and then there were people to talk to and it would happen. I call them “young people,” some of them might have been older than I was.
Anyway, that Higgs study was percolating along, getting lots of attention. As I say, the argument is powerful because it’s so simple. Anybody can repeat it. It doesn’t require a complicated derivation. So in June of that year, we were about to go off to the PAC [Program Advisory Committee] meeting in Aspen. Ned Goldwasser came to me and to Maurice Jacob, who was visiting at the time from CERN, and showed us Leon [Lederman]’s discovery, the Upsilon — the first two Upsilons. There had been a false alarm earlier. It was pretty embarrassing. This was real, and so that was exciting — you know, there’s something new to think about. We went down to lunch, sworn to secrecy of course. This was to be revealed at the PAC meeting. When I came back from lunch, there was a phone call from a county sheriff in western Illinois telling me that Ben Lee had been killed in a traffic accident driving to the PAC meeting.
That was absolutely shattering. He was ten years older than I was, he had brought me there. We had begun to form a bond. He was kind to our family, his family was kind to our family. And I was gonna be all alone. So we went off to the PAC meeting. On the way home, we’re flying back to Denver on one of those vintage DC3s of Aspen Airways that were 45 minutes of terror coming over the mountains in the afternoon, Wilson and Goldwasser told me that they wanted me to take charge of the theory group.
So this is preposterous. I was 32 years old. And there was no discussion of whether this was for a month or six months or longer. Anyway, they gave me a lot of encouragement and a lot of support. I’m sure there were lots of people behind the screen watching and helping. [laughs]
Anyway, I got to take over the theory group at that point. We had hired Bill Bardeen that year. He was still off in Europe before really joining Fermilab. Bill is John Bardeen’s son, Jim Bardeen’s brother, great physicist and a really good person. He immediately sent me — he’s a couple years older than I am — he immediately sent a note saying, “You have my full support.” [I led the group for ten years, until I joined the SSC Central Design Group. Then Bill took over.]
So that was the beginning of a trying time, but one that gave me opportunities. I mean, I still wonder what we would have done with Ben around, but that was taken from us.
Chris, when did your relationship at CERN get started? What was the point of contact there?
Dave Jackson had been at CERN in 1964–1965 and he had done some nice work there with Kurt Gottfried and other people. Maurice Jacob was sort of a protégé of his. I passed through there for a day or two in ’71, and in ’73 we actually went for an extended visit in the summer. So Maurice was probably the first person I knew, but I have to say that I had studied French at Yale, I liked the culture, I liked the mountains. Maybe my first contact — I’m trying to think the way I got there in ’71 might have been that there was an early colliding beams experiment [at the Intersecting Storage Rings], the Pisa-Stony Brook experiment, which was one of the two that discovered the rising proton-proton total cross action. My Stony Brook colleagues were there in the summer, so I dropped in to see them that first summer and met the Pisa people, which turned out to be important later on, when we began the Tevatron Collider program.
Maurice was probably the first person I knew well, but then I rapidly got to know John Bell, André Martin, a bunch of the other senior people. You know, it was a place where — many people find it impersonal, maybe it is. Somehow, because I had a few people who looked after me from the beginning, I didn’t feel that it was impersonal. And I felt from the very first visit that I was being treated better than I deserved to be, which is always a very good feeling.
Why would you feel something like that? Why wouldn’t you be treated as well as you should have been treated period?
There’s a saying in French that even false modesty is something. [Laughs] I mean you can’t go — I know all the things I do badly, right? We all have our moments, after all. No, I was just some random kid. Anyway, I always felt welcome there. Perhaps the fact that I got to know people in both theory and experiment from the earliest times was a help. Ugo Amaldi on the experimental side was somebody who took an interest in me. We had very, very good discussions with him and more and more with many people through the years.
I’ve gone there more and more frequently. It’s really a place that I love being. I’m close to people in the theory group. The current Director General [Fabiola Gianotti] is one of my best friends and so I feel that I have the opportunity to give wise advice, to the extent that I can, about CERN, and we can think about physics together. It’s always a good feeling to work with people and try to make good things happen.
And in what ways was the work that you were doing at CERN distinct from the work at Fermilab and then where was the overlap?
Well there was a good deal of intellectual overlap, of course the specific mix of experiments was different. The ISR [Intersecting Storage Rings] was the first proton-proton collider, not very high energy, but much higher energy [up to 63 GeV c.m. energy] than the fixed-target machine at Fermilab. It was under-instrumented at first and so it required thinking about how you would use that to get out some of the information we cared about. CERN had taken the brave decision, partly through the force of Carlo Rubbia’s personality by 1976 or 1977 to build the SPS (Super Proton Synchrotron) proton–antiproton collider. And of course I had done the work on W-Boson production so I was right in the middle of that.
And they were searching for charm, SLAC was searching for charm, Fermilab was searching for charm. There were things to be done about that. Some of the young people, relatively young people, like Guido Altarelli, somebody who became a great friend and colleague later, were domesticating quantum chromodynamics and making it useful for thinking about experiments and so on.
So it was — you know, one of the best things about traveling is that not only do you get to hear other people’s ideas, but there’s always somebody who will say, “Why are you doing it that way?” or “Why are you thinking about that?” And politely, gently, in a friendly way, challenge your own ideas and make you consider that there are other ways of doing physics, that there are other problems that you could apply your ideas to. I’ve always found it immensely broadening and stimulating.
At any point, were you more than half/half in terms of how you split up your time between CERN and Fermilab?
No, no. It was always dominantly Fermilab in those days. [I had a group to run.] I did have a sabbatical in ’81 – ’82 and originally, I was thinking of going to CERN for that year because the collider was coming on. It would have been a wonderful year to be there. And Maurice Jacob said to me, “No, you should go to Paris.” Now, I don’t know whether he just didn’t want to pay for me at CERN or he saw something [Laughs]. So he arranged for me to go to École Normale Supérieure in Paris, which turned out to be a fantastic place. It’s a grande école, it has a great tradition, had very powerful formal theorists, people doing string theory — some young people like Eugene Cremmer and Bernard Julia. But it had this tradition started, I think, by Philippe Meyer and Claude Bouchiat. Everybody who came through the graduate school had to first do a phenomenological problem and then they could do whatever they wanted, statistical physics, string theory, you name it.
So these were people who knew physics. John Iliopoulos was there and Pierre Fayet so it was a wonderful environment. It was fantastic to live in Paris. Every morning I went to Alliance Française so I could really speak French. They recruited me to give a class on quantum chromodynamics, which I did in French, partly to avenge myself for a Japanese math professor at Yale who was very hard to understand. I wrote Gauge Theories of the Strong, Weak, and Electromagnetic Interactions at École Normale — not quite the novel that young Americans dream of writing in Paris, but perfect for me.
So it was great and that has been a lasting — you know, if I have a third home, it’s École Normale, it’s Paris. I’ve been back there recently a couple of times for a month or two. It’s people I like, it’s an environment I like, and the fact that they are more theoretical than I am — or they’ve applied themselves in more formal ways than I have — means that it’s great to be around them because I can respond to their ideas and they can learn things from me. So it’s fantastic to have more than one home.
I should say that when I first got to Fermilab, I had just gotten a Sloan fellowship, another one of the nice things Stony Brook had done for me, and Ned Goldwasser and others conspired with people at Chicago to get me an appointment at the University of Chicago that was sufficient to satisfy Ned’s close friend on the board of the Sloan Foundation and I got to keep my Sloan fellowship. And that also opened up what became a very useful and fruitful connection with the University. I could go there, and starting after a few years, I gave my courses there. I would teach one quarter a year. That’s where my gauge theories book came from, courses given there; I also gave special topics courses on a variety of subjects.
That lasted until I went off to the SSC Central Design Group. When I came back, I didn’t feel it was working properly. I felt that they were maybe using my existence as a reason not to hire a young person and so we had a test of wills and decided to part company, which meant that after that, I had to commute to Cornell or Princeton to teach my course. [Laughs] So I’m not sure that I won the test of wills, but they did ultimately hire some young people, and so I think it worked out well for all of us.
Anyway, they had a wonderful department, people like Chandresekhar, Nambu, Telegdi, Cronin had his great group. And so I got to spend time with them. And I did have two graduate students there. They were fine, they did well: David Hochberg and C. H. Lai. But it was a little tough because Chicago had this tradition dating to the Fermi days that you should know all of physics if you get a Chicago PhD. And I think in Fermi’s time, it was accomplished very quickly and that you would do this before taking a research project.
Well these days, the imperative is to get into research as soon as possible. So you’d have these kids in their fourth or fifth or even sixth years who hadn’t completed all of the five or six one quarter introductory courses in various things. This meant that my graduate students, instead of being at Fermilab, had to be in Chicago over several days a week — we could get together by telephone or we could have an appointment once a week, but you know if you’re a student, sometimes you’re reading a paper but line 107 and line 108 don’t make sense and you need to go to somebody and hear, “Oh yeah, that’s a typo.” Or, “Oh, the author was confused about that,” or something. So that spontaneous interaction wasn’t occurring the way I liked. [Now we would have email and texting and Zoom!] And then when I got involved in SSC things, my life just became too busy.
So those guys are fine. They’ve had good careers. I enjoyed working with them, but it wasn’t a perfect arrangement.
And Chris, I wanna ask, how did you get involved in the SSC design work? Was this something that you had been following and you wanted to be involved or were you recruited into the process?
Well, following my work on searching for the W and Z and the work on the limit on the Higgs boson mass, you know the imperative of these high energy machines was going to be to explore the Higgs sector and to do all the things that you could do with that. CERN was doing very well. They had found weak neutral currents. They found the W, they found the Z. The US was feeling a little bit feeble, so there was a lot of thought about what we would do to carry our weight, pull our weight in the subject.
There was a design study at Fermilab that BJ Bjorken led to have the biggest machine we could fit on site, I think it was a three plus three TeV machine, proton antiproton collider, not very high luminosity, but a big step from what the Tevatron was going to be. The Tevatron hadn’t operated yet. And the Tevatron did turn on in 1983, had its first beam up to 512 GeV.
And Chris, I wanna ask on that point, what was so exciting about the Tevatron at that moment in 1983?
That it doubled the energy for fixed-target experiments; later, that it was the first super-conducting machine that had ever operated as a big collider. So it gave courage to think that you could think bigger. And by itself, it meant that we had the possibility of going to perhaps to 2 TeV in the colliding beam environment. So it was just going to — part of it was that we had finished the first run of experiments at 400 GeV. CERN had come on later with the Super Proton Synchrotron but with better instrumentation. And CERN was just gonna do better. CERN was going to do the SPS p-bar p collider, which looked like it would work and could find the W and Z. And so we needed to improve our game. The Tevatron was the way of doing that. It had been Bob Wilson’s dream from earliest times, but thanks to the work of Alvin Tollestrup and many others, it became real.
The US decided at that point, in 1983, in a HEPAP [High Energy Physics Advisory Panel] subpanel at Woods Hole [led by Stan Wojcicki] to go for a really big machine, a machine that became the Superconducting Super Collider, the SSC. So leading up to that, we at Fermilab had done a study of what this Dedicated Collider machine could do at Fermilab. I was the person who had done things like that before. Estia Eichten who had joined us, joined me, of course with Bj in the background as a benevolent presence and source of ideas. So it was quite natural that when this goal of a really high energy machine was created, Estia and I would start — I mean we had actually been supplying that panel with calculations and giving advice about what would make sense in terms of parameters. So it was natural for us to be doing that.
And then there were funny circumstances. Texas A&M was trying to recruit some young people, among them, Ken Lane, maybe Estia, it was never quite clear whether he was on their list. So the two of them and Ian Hinchliffe went to College Station, Texas, for the fall semester of 1983 where they had at their personal disposal one VAX 11 780 computer, with which we could do calculations to our hearts’ content. So we started writing the paper that became Supercollider Physics, which we finished in the spring of that year. And that became — [Leon] Lederman used to call it the bible of SSC physics. You never knew whether he was quite serious when he said something like that, but it was good to hear anyway. So I became more and more involved in the physics program for that. We did a couple of good things in that paper. One was we set out many possibilities and the other was that we provided the first modern set of parton distribution functions [PDFs] that people could use to do all sorts of other things.
Starting at Snowmass in 1984, other people began using these PDFs, doing many calculations. Snowmass really got the community involved in the scientific program that could be done by the SSC and other people extended it with new ideas. Still other people decided they could do even better than our parton distribution functions and that became a fantastic industry that people did in a very serious way.
I must have been giving 40 seminars a year on supercollider physics at that time. I think starting in 1984, I was put on the Board of Overseers for the Central Design Group. This was a group of worthies named by Universities Research Association to give a separation between the governance of Fermilab and the governance of the SSC [design group]. There were senior people — there was Panofsky and Steve Weinberg and Boyce McDaniel and Jim Cronin and Martin Perl, who else? — George Pake, John Deutch, Harold Furth, John Hulm, Ed Knapp, George Trilling, Sam Treiman, and me. I was 39 years old at the time, all these guys were gods, but I was a representative of the physics that could be done there. It was great to associate with those people, they were all really serious and I learned a lot about how to think about projects and life and physics from them.
This is finally getting to how I came to go to Berkeley. It was known that Ronald Reagan was considering this project. I’m off in Australia in the spring of ’87 with my wife and daughter. My daughter was 10. My son was 14 so we made one of these stupid parental decisions that his school was too important, he should stay at home and my mother came to be with him, so he got cheated out of a trip to Australia.
The school was in Tasmania where I was giving a bunch of lectures. And we’re off at Bondi Beach in Sydney on the way to Tasmania. We come back to our hotel room, there’s a telegram on the floor, my daughter scoops it up, reads it, and says, “Does this mean we have to move?” And so this was the news from Estia that Reagan had blessed the SSC. It was going to happen. So my daughter —
Uh-huh. You mean Reagan personally, not just the administration. That was the sense, that the president —
Ronald Reagan personally, that’s right.
The Great Communicator.
So we must have brought her up right. She was so perceptive. After we got back from Tasmania, Maury Tigner came to my office at Fermilab and said, sort of, “Well, how much do you believe in this project, kid?” The opening was that Dave Jackson, again, my teacher, had been serving as one of Maury’s deputies and he was going back to teaching and writing the third edition of Classical Electrodynamics. So they needed a new body and Maury asked me to do that. There was infinite back and forth with the Department of Energy because certain people were fearful that my presence would give Fermilab too much influence in the site selection.
So we’re trying to decide can we rent a place? Can I put the kids in school? And things like that. The DOE is fluttering around. Eventually they blessed it, so in June I went out to Berkeley and joined the CDG as one of Maury’s deputies — I was called the Deputy for Operations, which meant anything we needed me to do, including some technical things. Maury’s other deputy was Stan Wojcicki from Stanford who was the Deputy for External Relations, so he was into communications. He’d go anywhere and talk to anybody and educate the Congress and so on. Another really talented guy, an amazingly fast study. You know, he’d be on the road for four days a week, come back to Berkeley, and absorb everything that we did and be pushing ahead on things, so just a pleasure to be with. Anyway, that was a great experience.
Chris, the story of the rise and fall of the SSC is something of a cottage industry and I love getting as many perspectives as possible. So in those early days to sort of foreshadow a little bit, how involved were you in some of the budgetary questions? Were you thinking, you know, besides the technical questions of how to pull this thing off, how involved were you in the bigger questions of, you know, exactly how much was this going to cost?
We all had to be involved in all of that and the cost did go up, but there was a certain amount of willful misrepresentation of not using the right units or not recognizing what the units were and exaggerating the degree to which the cost had gone up. My direct involvement ended pretty much when the lab started in Dallas. So I don’t have inside knowledge of that. I think it could have been done better after that point.
The story of the fall is pretty complicated. It’s not at all simple and it’s a great loss, it’s a great tragedy.
Yeah. In those early years, did you ever have misgivings that this was just not feasible from any number of perspectives or were you pretty optimistic that this — at least in those early years — that this was actually gonna happen?
I remember visiting a senator who said, “You’re young, why are you spending your time on this? This is never gonna happen.” And I told him all the reasons that it had to happen. The other lesson — I was wearing a pretty good J. Press suit that day and he was wearing his Sears Roebuck suit so I decided when you go to educate a senator, you shouldn’t dress better than he does.
No, I was convinced that we could make it happen and I’m convinced to this day that we could have done it. That’s part of why it hurts so much.
So the would-have-could-have, what do you see as the biggest mistakes that made a feasible project impossible?
I can’t give a one word answer. Maybe I’ll be ready to bare my soul some day, but it’s very complicated. It had to do with a lot of politics, you know, fluctuations — things live and die on fluctuations, this one died on fluctuations, including the fact that the power of the Texas delegation crumbled and not all of the members made friends the way they should have. I felt the lab could have done its work better. I wish physicists in other fields had been less paranoid. If we had worked together, we could have made this — as well as many other good things — happen. But, you know, in human affairs, things happen that, on average, should not happen. And this is one of them.
To what extent did CERN pick up all of the physics that would have been done at SSC and to what extent did it not in terms of all of the things that, you know, technically or at lower energies could not have been accomplished had — only if SSC had been completed?
Well the SSC had a higher energy, which would have made experimentation far easier. You could have operated at lower luminosity, lower event rate than is done at the LHC. Carlo Rubbia — he’s somebody I knew from Fermilab, of course — had read and understood our paper on supercollider physics. And so he was determined — and CERN had the advantage of having a ring, the LEP tunnel. They had the disadvantage of having a ring that was of a known, fixed size. So that set a limit on the energy you could anticipate for the LHC.
And Carlo realized that to some degree, you could compensate for the lower energy by really pushing on the luminosity. And so he announced a luminosity that was 50 times the luminosity that the SSC would have had. Amazingly, we’ve gotten within a factor of two and a half of that, so far. And people have learned to operate detectors that actually thrive in that environment, which was not at all obvious at the time. One of Carlo’s gifts is that he can make outrageous promises and then he attracts brilliant people who make them happen, even if he breaks their spirit in the course of it. [Laughs].
Anyway, at the time, when we were still trying to do both, I thought that it was to our advantage that this was his response because if he or CERN had said, “These guys don’t know what they’re talking about. We’re gonna build a little machine that we can do today, you know, three on three TeV or something like that with simple magnets. You don’t need that big machine to do the physics.” Then we would have been hard — that would have been a different front on which we had to argue, but they agreed on the scientific imperatives and on, you know, how you had to stretch yourself to get there. So I found that the kind of honesty that you expect from other scientists — to really agree on what the parameters are.
I had one experience early on, I think it was in 1990 — just when I had gone back to Fermilab — ECFA, the European Committee for Future Accelerators was having the first LHC workshop in Aachen. And I went to it, not as a rival or a competitor, but as a colleague, somebody who wanted to help make that happen as well. I thought it was fine for the world to have two of these things.
And people were so into the, “The Americans are going it all on their own and not consulting us,” trope — which was an exaggeration, a motif that people who should have known better were repeating — that people were actually moved by the fact that I was there as somebody trying to help. That, I think, influenced my — it further cemented my connections with CERN and the warm welcome that I got from people always. And that we were in this together, we were all trying to do really hard things. It seemed to me natural. They were trying to do something good, I wanted to be part of it, and so on. It’s not that I came carrying money bags full of coins or anything like that. I just was there as a supportive presence and somebody who knew something about colliders and physics. So I didn’t go there out of any great calculation, but it turned out to be important that I was present.
By the way, about ten years ago, Luciano Maiani, who had been Director General, was back at CERN for a sabbatical while I was visiting. One afternoon, he burst into my office and said, “Chris, I’ve been thinking … you should have built the SSC. It was the perfect machine!”
Chris, I just want to understand, your association with SSC, was it strictly on a consulting basis or was the plan that had it gone through, you would have made the move and you would have sort of worked full-time for SSC?
No, it was a temporary assignment. I was on leave from Fermilab at the SSC Central Design Group, which was a national group set up in Berkeley, as it happens, to bring people together outside the influence of any of our existing laboratories (SLAC, Brookhaven, Fermilab, Cornell) to work on preparing a design and getting the project approved. Maury Tigner was chosen as the director of it. Very inspired choice, great leader. When the SSC laboratory was established Roy Schwitters was made director of that. That was a separate successor organization, that was a new thing.
I could have gone there. In the end, I think I might have been a minister without portfolio or something. You know, I’d already started a theory group at Fermilab, so I’d done that once in my life. There wasn’t a job there that appealed to me, so I decided not do to that. I did have some involvement setting up their fellowship program, setting up the scientific policy committee and so on. After the kickoff meeting in, what was it, 1989, in the fall, I think I gave the keynote speech, launched the ship, laid the keel, whatever it was, and then I got on an escalator and rode out of the hall and that was my last official act.
Later on, they asked me to join the Program Committee, which I did, just at the wrong moment before the thing went down. Anyway, so I didn’t move to Texas. I had to decide what to do with my life. Toward the end of the time — the relations between the design group and the laboratory were not all smooth. I tried to do my best to get people to go from the design group to the laboratory and to ease their path. I succeeded with some, I failed with others. I wasn’t paying attention to what I was going to do next.
Luckily, my friends in Berkeley, Pier Oddone at the lab mainly, agreed to keep me on for a year at LBL as sort of a sabbatical after we closed the Central Design Group — my son could finish high school and I could catch my breath and decide what I would do next. So I looked around a little bit. There was interest — a number of people wanted me to become a university administrator and that didn’t seem who I was. I was interested in being with physicists, as you say, having students, maybe being a mentor to graduate students, and I had some discussions with some good universities, serious places.
Of course, I was coming from this background at Fermilab where I had a huge group of great people. I’d go up and down the halls, people were doing good things. We could attract — we were one of the institutions that competed for the best postdocs, and so I didn’t want to just go to a place that would put my name on the door in gold letters, I wanted to be able to do something. And I didn’t find such a situation.
So eventually I went back to Fermilab. It wasn’t perfect. You can go home again, but it’s not the home that you left. Bill [Bardeen] used to tell me he didn’t think the lab had changed as much as I had changed. Some people questioned my allegiance. So the match wasn’t what it had been before, but it was pretty good.
Chris, I wanna ask, at this point when you were working on the SSC design, were there aspects of the SSC that you thought might render some of the work at Fermilab redundant or old-fashioned? Was there any awkwardness around those kinds of issues or did you understand what SSC was designed to do as complementary, next-generation, and not necessarily, you know, an existential threat or any other kind of threat to Fermilab’s long-term viability?
Well, for the first year or so, Fermilab was still in the running as a possible site. I have to say, I didn’t give a lot of thought to that. I wanted to get to the physics. I didn’t see that necessarily, even if the SSC lab would go elsewhere, I didn’t see that there was necessarily a threat to the existence of Fermilab. You know, that all would depend on how things were handled. Fermilab could have done — I guess I imagined that Fermilab could be a base for one of the experiments at the SSC laboratory, the same way that I imagined that SLAC might have been a base for one of the experiments. SLAC faculty didn’t see it that way.
So for the first year and a half or so, until November of ’88, we didn’t know where the site was going to be. For that last year, from November to August, indeed it was clear that it was not going to be at Fermilab. It was gonna be in Dallas. But we were trying to make something wonderful happen. I certainly wasn’t indifferent to the welfare of Fermilab, but it was not uppermost in my concerns. I thought a good laboratory would find things to do. You know, I always say that any place like ours, any of the great laboratories, even including CERN with all the treaties behind it, has a horizon of maybe a decade in the absence of a good idea. You always have to come up with something new to make you good enough that people want to work there.
So to me, the question was not whether Fermilab would exist, it’s whether it would be an interesting place; one would have to make it an interesting place.
So on this question, when you returned about what had changed, you know, how had you changed, how had Fermilab changed, how did you work all of that out? Because obviously you did because you stayed.
I stayed. Well, it’s wonderful colleagues, right?
So, I had been — Maury and I had agreed when I took the job, that I could have one day a week to do physics, and he said, “This is easy to promise because you won’t do it,” and he was correct because we were so absorbed in what we were doing, I would be able to go to theory seminars and colloquia once a week at Berkeley, but I wasn’t doing independent research. The work we were doing was too engaging.
We started coming in on Saturdays, just Maury and Stan and a few other people and I, so we could get some work done because the other time we were interacting with everybody else. He had inspired people so much that the rest of the staff started coming in on Saturdays, and we were clever enough to realize this is getting excessive, you can drive people for so long and then, you don’t want to kill them. We said, “This has got to stop. We can’t burn these people out.” You know, you’ve got a deadline, that’s fine, you give blood. So somehow we met secretly or did something and tried to keep people sane, but it was just fantastically engaging work — for everyone.
Some of the people that we had as visitors or as staff members were among the best. Others were just good citizens who gave more than they knew they had to give. When you make a winning baseball team, maybe you don’t have an all-star at every position, but you have people who are putting out at every position, and these people were really putting out. So there was no holding back to go and say, “Well, I’m going to go write a paper to enhance my reputation as a theoretical physicist.” I had to be all in for them.
Anyway, because of this intensity, one loses a little confidence in research. I think if you do an administrative job full-time for five years, you’re probably done with research for life — you have to do something else. After three years, it did take some time for me to regain confidence that I could find the right problems, do the right things, make people pay attention to my ideas. My Fermilab colleagues, from postdocs to senior staff, helped me.
You mean to get your muscle memory in physics back, essentially?
Yeah, be relevant and, you know, just trust my judgment. At Fermilab, we have the advantage of not just theoretical stimulation, but of the experimental program for thinking about what you can do. The Tevatron was in full motion by the time I got back. The top quark search was still underway. We were trying to understand what we could do in B physics: CP violation, which I hoped CDF might first observe, B_s, B_c, b-baryons.
So this was actually a pretty dynamic time at Fermilab when you returned?
Indeed it was. You know, the Tevatron had, for 20 years, it was — together with LEP and the Stanford Linear Collider, which had very important but a little more restricted programs — it was one of the centers of the universe for experimental physics.
So it was really, really good to be there and that gave me an opening to do things again.
Had you stayed on top of the literature during your sojourn or you had to play catch-up in that regard as well?
I was pretty aware. I was pretty aware. You know, there were some things that happened that, in a different life, or without the diversion of the Central Design Group, ideas people had, that I alone or I and my collaborators at Fermilab would have jumped on right away and done something with. So those things didn’t happen, but I was aware that those ideas were there and what the developments were.
So what did you get involved in after you got comfortable back in?
Oh, it was more heavy-flavor spectroscopy, the search for the top quark. I wrote some papers on top after it was discovered, started thinking about the implications of that. The Higgs was still there, since the paper with Ben and Hank this had become my white whale. You know, how do we find the Higgs boson, what are the ways that you do that? And the SSC and the LHC were both coming.
There was a period right after the collapse of the SSC in 1993 when I have the testimony of my wife that I was depressed. I wouldn’t be surprised. My brother had serious health issues at the same time, so I think she’s right. I was depressed. But that was — well, it would be excessive to say that the SSC was a child that died, because losing a child is really serious — but it was something that I really wanted to have happen and I thought could happen. It was a great blow to me that the country had failed and that we physicists had failed to make it happen.
Did you sense that this was a once in a lifetime opportunity and that the United States had ceded its leadership in high energy physics forever or at least in your lifetime?
I’m actually more worried about that now then I was then.
Wow, okay. That’s interesting.
Maybe it’s — I keep saying it’s an aberration that… You know, the related example I give is we live in a nice town, good schools. Some of my fellow citizens whose children have graduated from high school now routinely vote against all borrowing for the schools because it doesn’t do anything for them — except keep the kid next door from being on the street unemployable and things like that. And there is a spirit of community engagement and doing challenging things together that I — maybe falsely — attribute to the America of my childhood. And it hasn’t been around, it hasn’t been evident in the same way for, now, a disturbingly long time.
I want to think it can come back and if it comes back, then doing impossible, demanding things in science should be part of that, but we’re in a funny place.
And what are your thoughts on the ILC?
The idea of a linear collider is a lovely idea. It’s an idea that is lovely for about one order of magnitude in energy, up to about one TeV in the center of mass, which turns out to be a pretty interesting order of magnitude in energy. And then barring some technical developments that we would have to make (talked about in terms of the CLIC [Compact Linear Collider] Project at CERN), it’s hard to see it going much beyond a TeV.
There was a time when I was pretty enthusiastic about that. We thought at the time that, in addition to the Higgs boson — which you would make in a clean way there — that there might be many other things that you would do. That seems less likely now unless the LHC experiments have missed a remarkable number of dramatic discoveries.
And after 2001, when we organized the Snowmass meeting and decided that — and then DOE and then the government subsequently decided that — a linear collider was a goal. One of the things that we did in the wake of Snowmass was to invent a working group led by Barry Barish that would go off and study the practicalities. I was very discouraged by what turns out to be the cost of the machine. So with some reluctance — because I think it’s a beautiful idea and if the Japanese decided to do it I wouldn’t rain on their parade — with some reluctance, I would be hard-pressed to argue for it as a good investment at the price I think it is. (Maybe that turns out to be wrong.) So I don’t know whether it will happen or not, but I’m much less enthusiastic than I once was.
What do you think — what are the new physics to be discovered if it does go through? And I ask that in the context of your hesitance to say, you know, any price tag is worth it, right? So you must be qualified in terms of your excitement for where physics might go as a result of the ILC coming online.
Yes. It will improve our knowledge of the Higgs boson. On paper, the electron positron version of the Future Circular Collider at CERN, the 100 kilometer machine, would do a better job on the Higgs boson at the price that you have to invest in a very large tunnel and that it’s not gonna happen the day after tomorrow. So that’s a disadvantage of that proposal. If you believe what everybody says in their proposals, I find the FCC-ee a more attractive machine. It can go to higher energy [than the first-stage ILC], to the top threshold. It can be a huge source of Z bosons, 10 to the 12 or so, which is very interesting for electroweak measurements and probably also for heavy flavor physics, all the B mesons and charm particles that you would make.
So if I just had to choose between pieces of paper, the FCC-ee would be my choice for a Higgs factory. I think that would be a superb machine. The trouble with all of these things — and this is something that you have to get used to and you always have to be meticulous about — whenever you’re thinking about some new machine, you have to put yourself in the frame of mind of what will it contribute to physics — not today when it’s not going to happen — but on the day it actually comes into being?
And there are delays associated with this much larger machine. We’d have to get permission to bore the tunnel and funding to build such a large thing. It has the advantage that you could start building the components for it today. It’s not an easy machine because its parameters are so demanding, but it’s a straightforward machine. It’s one that human beings can certainly make.
So the thing is — and it’s been the case since the Higgs boson was discovered in 2012 — if you could say tomorrow, no delay, no extravagant cost, I will give you an e+ e– machine as a Higgs factory, a third of the people on the LHC experiments would walk across the street to use that machine because it’s so appealing to get that second look, a different kind of look at this new particle. It really is that important.
And so the question is how we get there, when we get there, what it means, who takes the lead. So with respect to my current assessment of the linear collider, I wish it were otherwise, but that’s where my head is today.
So Chris, that’s a good segue to bring the conversation up to your more recent work — you know, within the context of the absence of these large-scale projects or even the absence of any prospects that any of them are actually gonna come to fruition — can you comment generally where this leaves physics and where and how you have responded to it specifically? What are the ways that you have, in recent years, continued to move the dial forward, continued to do interesting physics knowing that these new, exciting projects don’t exist now and might never exist in the future?
Let me start with the end of that and then I’ll come to the physics part which is — I’m glad you asked — is very important. To start with the end of it, I was asked by Weiren Chou and Alex Chao, my old student, to write the introduction to the last volume of the Reviews of Accelerator Science and Technology, which I entitled Dream Machines, and it was partly meant to be a hymn to accelerator physicists. That was part of the charge I was given, to express my appreciation, but also to begin to give a list of questions that I would like particle physics to answer.
One of the things that I called to mind there is that — so I have a faith, maybe a naïve faith, that no good work is ever wasted. You know, you do a calculation and it doesn’t work out, your experiment’s not done, something like that, you still learn from it. And as long as it was good work, it will be valued — perhaps not immediately, but in time. And that’s true for accelerator designers as well.
But the particular challenge there is that the time scale is so long, the uncertainty associated with whether a project would happen is so great, that we, the community of consumers of these accelerators — whether experimentalists or theorists — have to find a way of making career paths for the people who give us their souls and bodies to do this work. And to make sure that we don’t just say, “Oh, that project’s canceled. You’re gone. We don’t need you anymore.” We have to figure out how we do that. I think there are ways.
Traditionally, accelerator physics for particle physics has been the source of accelerator developments that are applied in other fields: light sources, lithography or who knows what, making medical isotopes. Having more accelerator physics in the universities would be a good thing. If you’re in the universities, you learn what other people need and can use — condensed matter physicists, atomic physicists, etc — and you learn from them. So that is a goal for us I think, to try to implant more accelerator technologists into the universities as full-fledged physics professors, both for their career longevity and for the intellectual stimulation they will receive and that they can deliver to their colleagues in return.
We have similar problems for young experimenters — the life-cycle of an experiment, it’s so large — but I think we are learning adiabatically how to deal with those challenges, modulo the current great economic crisis, which is going to inhibit universities from hiring for a while. We have to find our way through. But I think it’s a deeper challenge for our young accelerator physicists and we need to fix that. Life can be challenging for young theorists as well, but time constants are less a factor.
So on the physics, the physics is actually quite glorious. It’s true that we haven’t found any new “fundamental” particles, beyond the Higgs boson. We learn more and more about the Higgs boson. So far it’s turning out to be — the evidence is developing as if it were a standard model Higgs boson, so that means what is written down in the textbooks like mine and by the founders. But there are openings to do many other things. Maybe the Higgs boson is a portal to something new, to some new sector. Maybe it will yet surprise us.
The other thing is that — when we develop the case for accelerators, we often think of what the headline will be, the result on the marquee. Sometimes that mentality works against small experiments because you weigh the marquee measurement against the whole cost of the experiment and people decide whether they match up or not. All these experiments are really institutions. They’re like laboratories used to be. They do hundreds, thousands of things. The CMS experiment just published its 1,000th paper. ATLAS is about to do the same. LHCb is running at two thirds of that rate.
And LHCb for example, which hasn’t done Higgs physics, hasn’t made that particular great discovery, has done a lot of flavor physics that is very stimulating. Some of their answers are provocative, not yet decisive discoveries of new phenomena, and so there’s plenty to pay attention to. I can’t actually read all the papers that come every day from the LHC. When we judge what is being learned, it’s important to see the whole context and to pay attention to those new results. You know, they’re not just meaningless measurements. These are serious analyses that will teach us something about nature.
One of my little hobbies has been — and I wrote some papers about this before the LHC was starting up — is our conception of particle production, all the pions, etc., that are produced in high energy collisions. Now, it’s not a fundamental problem in the sense that you can study that and you’re not gonna learn a new term in the Lagrangian of the universe. But if you’re a physicist and you say you understand the theory of the strong interactions, you ought to be able to understand things that actually happen in the world.
Our notion of how particles are produced comes basically from the early bubble chamber experiments at Fermilab: 50,000 pictures — not all of which had real events in them — at (now) low energies. We break it into two components, diffraction, which is to say the excited projectiles falling apart plus what’s made from the interactions in the middle. It’s plain that more things than those may be going on and it is likely that more mechanisms should be seen as you go to higher energies or maybe as you have nuclei as the targets or maybe as you select events that have very high multiplicity. And if we can find those hints — maybe it’s not the problem that I will work on, maybe it’s the problem that people who care about hydrodynamics will work on — but there’s real physics to be found there.
And there are things to be mined about flavor physics. It has turned out that in spite of all the [particle] tracks that come out of these collisions — people have learned to deal with 70, 100, 200 interactions occurring in the same bucket of accelerator particles, protons — there are many things that are now in the realm of rare decays that can be studied at these large machines.
So I think we need to pay even more attention — and luckily, the community is large enough that many people are engaged in this — but as a community and in terms of what we convey to others, the richness of these investigations — and all the things that you might be able to do with them — is something that we need to convey better and that we need to convey better to our students.
Now, there are other things: Fermilab and our friendly competitors in Japan are both engaged in big developments in neutrino physics, where we learned some tantalizing things in the last decade or two that need to be followed up. The search for dark matter happens not only in colliders, where we hope we can make it and therefore understand what it really is, but in passive experiments in which you hope to detect our motion swimming through the sea of dark matter particles. There are searches for neutrinoless double beta decay that people are doing at stupendous sensitivity.
One of the things that the standard model has given us is a common language in which we can approach the problems and the experimental opportunities in many different domains. And so people doing collider physics can understand the import of what people looking for neutrinoless double beta decay are doing and vice versa.
At a somewhat more applied level — if you consider the work of people who call themselves, as is traditional, nuclear physicists — but who in many cases are doing applied quantum chromodynamics, in a way that’s different from the perturbative quantum chromodynamics that most of us do most of the time. You know, we’ve gotten by for a long time, nearly 50 years, with the idealization that a quark in a proton is only moving in one dimension in the direction of the fast-moving proton and you can neglect the transverse momentum and you can neglect correlations between the quarks inside the proton, for most purposes. These people know better. And so they have techniques that they’re devising. This is the domain of the electron–ion collisions or electron–proton collisions in which they’re able to be sensitive to these little details of proton structure.
It’s fair to say that to me, that’s sort of like organic chemistry except it doesn’t smell as bad as organic chemistry does, but it’s real science. It’s applying the knowledge that we’ve gained through the high-energy experiments and either finding that we know how to employ that knowledge successfully or that there are surprises, there are things we didn’t anticipate.
Our condensed matter friends make a big deal about emergent phenomena, correctly so. They neglect the fact that particle physics is full of emergent phenomena, starting with confinement of quarks and the mass of the proton, chiral symmetry breaking, and such. There are places in which, going back to the Lagrangian is not the right thing to do, not the most economical approach.
String theory stretches people’s minds in many directions, most of them mathematical for now, but the notions of duality are very rich. Maybe we’re going to find ways to use those insights, even more directly for experiments. We’ve already used some of the calculational techniques to make predictions for experiments, but there’s a lot of physics out there.
Now, I believe it is essential to us to go to higher energy, for one thing. If I go back to my little thought experiment of colliding W bosons together, one of the things we learned from that was that the Higgs boson is essential for making that cross-section behave at high energies. So not only before I die, but while I still remember the question, I would like to see that verified by experiment. Or to be told, “You’re full of it. Something else is going on.”
That would be wonderful.
You’d like to know either way.
Yeah! When you’ve got a theorem and it’s violated, either you made the wrong assumptions or something new came in, and there’s something to be learned. And so if I go back to my first fascination with the colliding beams experiment at Stanford, hearing these guys say, “We don’t know what will happen,” that, to me, is the essence of the adventure in particle physics.
I do hope, you know I’m working as hard as I can as an outsider on the FCC project giving sage advice. I talked about being on the SSC Board of Overseers and being the youngest person in the room, which was my lot for many years. Now I find on the FCC International Advisory Committee I’m the oldest person in the room. Somehow being the youngest person in the room seemed completely natural to me. Being the oldest person in the room doesn’t seem so good, but I’m glad I’m still there. [Laughs]
Well, Chris, I think for my last question, I wanna ask something that’s both broadly retrospective and also something that would ask you to sort of, you know, use your powers of extrapolation to give some predictions about where things might be headed and it has a pretty strong sociological component to it because you’ve really talked along those lines in terms of emphasizing the importance of your colleagues and collaborations, right?
When you were present for the beginning of so many of these creative and important endeavors in physics, and in light of your very legitimate and well-founded concern over, you know, the lack of new initiatives in the future, what is it in the past that the physics community in America, in Europe — what was it that it had that seems to be lacking today and how might we harken back to those earlier times in big science to sort of rekindle that spark to make physics of the future as exciting as it once was?
I find that Europe still has that spark. I mean, let’s put aside the current situation which is certainly going to be a dislocation for some time —
You’re referring of course to the pandemic.
I’m referring to the pandemic. You go to CERN, there are many young people there. People would like to have made even more discoveries, but there’s plenty going on. There’s a certain reality [of time spans that we must face]. CERN has now set out — or the European Strategy Group — has set out a plan just released by the CERN Council that has a 70-year horizon for the creation of new devices and so on. So on the one hand, fantastic. There are things — and there are good things — to do.
On the other hand, I ask — suppose my hero, Enrico Fermi, had told us 70 years ago what we should be doing today, would I trust him? And I think the answer has to be nuanced. Probably in general terms, yes. But you know the physics that we’re doing today didn’t exist when I first started graduate school. It didn’t exist when I first went to Fermilab. Physics is changing all the time.
And so we’ve tried to make this plan — my European colleagues have tried to make a plan — that will be adaptable and that will respond to many imperatives and that doesn’t foreclose other things, new opportunities. We’re just learning what the connection between particle physics and gravity waves might be. We are learning more and more about astroparticle initiatives. There are things like the ultra-high energy neutrinos coming from way out there that may have things to teach us that we can’t learn from accelerator experiments on earth.
I’m a very vigorous proponent of diversity and scale diversity when we make our plans for the future. But I do think that large machines are an inevitable part of those plans. They’re irresistible because there are things we can only learn in that way.
I’ve been giving seminars recently about future plans, future opportunities, and I think in the course of an hour I list more than 110 questions. Some of them are marginally metaphysical. Most of them are specific, but not that specific. They’re things that will grow as we get into them and get the answer to one or find new paths. So in spite of the challenges and what I see as a lack of swagger on the part of the American community and of the American body politic for the moment, I wouldn’t mind being a young person and starting again.
You know, people always ask, “Would you do the same thing? Would you do particle physics again?” Well, who knows? I got into this by happy fluctuations. And one of the great things about science right now is that there are many interesting subjects in which a young person can make a difference. So I can’t tell what the young Chris would do today. But I would say that there are plenty of problems to work on now in particle physics that I find utterly fascinating and on which I think we can make progress.
For me, and this is partly my fascination with the large machines, the large machines will be part of that. We need inventions; we made the invention of strong focusing, we made the invention of active optics, we made the invention of superconducting magnets, we made the invention of colliding beams enabled by our control over the beams through the active optics and strong focusing, and it would be wonderful to make new inventions.
Our people are working on some of these, high-gradient acceleration and such. People are making wonderful strides in detectors, even using atomic interference and things like that to extend our senses. We need to do better. We need to make inventions and I hope my colleagues will do that. And that we will justify the support society gives us and that society will continue to invest. As I say. in Europe that is still present to a large degree.
There are autocrats coming into power, there is Brexit, there is the pandemic. Life is not easy, but the faith that people can do really hard, meaningful things together is quite important. I see it more in Europe than in the US at the moment, and I hope we get it back soon.
I hope that we get it back soon, too. Are you an optimist on that? Cautiously?
[Laughs] Well, Chris, you’ve made it clear that, you know, there is much fundamental work to be done. And so that in and of itself is something to be optimistic about. How it happens maybe is a different story, but there’s certainly what to work on, right?
Indeed there is. We’re still attracting many gifted people to the field, we’re making connections with other fields. So at that level, there’s every reason for optimism.
Well, Chris, on that note, I wanna thank you for the time you spent with me today. It’s just an enormous wealth of insight of institutional memory you’ve shared with me. This is gonna be of such tremendous value to our collection. I’m so glad that we connected and I wanna really thank you for spending this time with me.
Well, you’re very kind to find me and I’ve enjoyed our conversation. Let’s do it again.