Jerome Friedman

Zierler:

Okay. This is David Zierler, oral historian for the American Institute of Physics. It is August 12, 2020. It is my great pleasure to be here with Professor Jerome I. Friedman. Jerry, thank you so much for being with me today.

Friedman:

My pleasure, David.

Zierler:

Okay. So to start, would you please tell me your title and institutional affiliation?

Friedman:

Yes. I am Institute Professor and Professor of Physics, Emeritus at MIT.

Zierler:

What does the designation Institute Professor mean?

Friedman:

It’s an honorific title which one gets after years of working hard and maybe accomplishing a few things here or there. [Laughter]

Zierler:

Do you know how many other professors at MIT hold this designation?

Friedman:

It’s on the order of, at any particular time, of between 12 and 15.

Zierler:

Oh, wow. Wow. And you received this before or after you went emeritus?

Friedman:

Before. I think it was in 1991.

Zierler:

Ah! So it was obviously connected to the Nobel Prize.

Friedman:

Correct.

Zierler:

Right, right.

Friedman:

Well, I also had done some administrative work . I was head of the physics department and of the Laboratory for Nuclear Science, so I had done some additional work at MIT. I also served on many, many committees.

Zierler:

Right.

Friedman:

You know, I was one of these people who could never say no to a committee assignment. [Laughter]

Zierler:

And you were probably good at it, so you were awarded with more committee assignments. [Laughs]

Friedman:

Yes, yes. That’s the main problem with being competent. [Laughter]

Zierler:

Exactly! Jerry, let’s go all the way back to the beginning. I want to start first with your parents. Tell me a little bit about your parents and where they are from.

Friedman:

Well, my parents were from Russia. They came from an area which is now called Belarus between Minsk and Pinsk. My mother came from a shtetl called Motol my father from Slutsk. My mother came to the United States in about 1914, and my father also came roughly at that time.

Zierler:

And they met here or in Europe?

Friedman:

They met in Chicago. My father served in World War I not long after he arrived, and as a result quickly became quite acclimated to the United States.

Zierler:

Did your parents speak Yiddish to each other when you were growing up?

Friedman:

No, they didn't.. They took English courses after they arrived here, and they made a practice not to speak either Russian or Yiddish in the household. They only spoke English. However, they would speak Yiddish to friends, and so I got to learn a little Yiddish here and there.

Zierler:

Did your parents come from religious families in Europe?

Friedman:

No, not particularly. My father was a free thinker in the sense that he really had abandoned religion. My mother actually would adhere to some of the religious practices at home. For example, we had a kosher household, although she would eat non-kosher food out of the house. So, she did not go to the synagogue regularly. However, my mother wanted me to have a bar mitzvah, so I went to Hebrew school and I learned all the rituals. I had a bar mitzvah and that was it.

Zierler:

[Laughs] Did you proclaim your atheism shortly thereafter?

Friedman:

No, I really was careful not to do that, but I lost my belief system quite quickly after that. So my feeling about declaring atheism is I don't want to offend other people. People can believe whatever they want, only with the requirement that they don't tell me what to believe. [Laughs] That’s the only requirement.

Zierler:

That seems to be a fair requirement.

Friedman:

And whatever they want to believe is fine with me as long as it doesn't cause any harm to others or force others to believe in the same way.

Zierler:

Jerry, what were your parents’ professions? I’m curious specifically how they fared during the Great Depression.

Friedman:

Well, they were both really uneducated. They had had no formal education when they came to the United States. I think my father became an apprentice at the age of 11. My mother was raised in Russia, and at that time women there in general did not go to school. She had a tutor here and there at home, but she really didn't have any formal education. However, my father was quite self-educated. Our house was filled with books. He read quite a bit. He was interested in science and in politics. So though they did not have a formal education, they really educated themselves to a large extent. And of course, when they came here, they both went to English school; and there may have been some content there that they were taught in addition to the English language.

Zierler:

Now what neighborhood did you grow up in in Chicago?

Friedman:

The northwest side. I don't know whether you know Chicago, but it was on Lawndale Avenue, which is between Kedzie Avenue and Pulaski Road, and near Chicago Avenue. It was 500 North, in that area.

Zierler:

Was this a European immigrant kind of neighborhood?

Friedman:

Yes, primarily. It was actually quite a mixture — mostly Italian immigrants in that particular neighborhood, so I grew up with a lot of Italian friends who came from immigrant families.

Zierler:

And you went to public school throughout?

Friedman:

Yes, I went to Ryerson Elementary School and Marshall High School.

Zierler:

Jerry, I’m curious if you figured out or you had teachers who understood that you had some special aptitudes in math and science, even perhaps before your formal exposure to those subjects in middle school and high school.

Friedman:

Now that’s quite an interesting story, because as a child, I loved to paint and draw; and I was reasonably good at it for a child. My aspiration was to become an artist; and of course, in elementary school there really wasn’t any real mathematics taught. There was only arithmetic, — the multiplication tables and addition and subtraction. I did reasonably well at that, but it wasn’t my aspiration. I went to a high school that had a wonderful art program in which you could draw and paint a couple hours a day. I didn't take much mathematics. I took the first course in geometry and a course in algebra and that was it. I never took trigonometry and at that time calculus was considered a college subject. [Chuckles] But I did reasonably well in art. In fact, I won a national prize with one of my art pieces, and I thought I was well on my way to becoming an artist.

At the end of my third year, I went to the Museum of Science and Industry for a visit. I went to the bookstore and picked up a book on relativity written by Einstein for laymen. I had heard about relativity from my parents because Einstein was regarded as a national hero. He would make wonderful public statements about various topics, and he was obviously a genius.

Zierler:

He was also a point of pride for Jews in America as well.

Friedman:

Absolutely! It was quite remarkable what sort of individual he was and what he had accomplished. So I said to myself “, relativity always sounds so interesting — moving clocks that slow down and meter sticks that shrink. How does this all work?”

So I picked up this book, — it was at the beginning of the summer — and I spent the whole summer going through it. I did have algebra, so I could go through the Lorentz transformations. I did go through them, but I didn't understand them because, the concept of the velocity of light being the same in any uniformly moving reference system, was something I couldn't understand. After all, if you shoot a bullet from a moving train, the bullet gets the train’s velocity and you have to take that into account. I couldn't understand that, and it wasn’t till I went into physics that I understood it.

But the point is that I found it so fascinating that I said, “I really want to understand these things,” and I decided that when I graduated from high school, I wanted to study these things at the university. I had an art scholarship to the Museum School of the Art Institute of Chicago. I had done well academically in high school. I was among the top students. In fact, I tied for the best score in the high school graduating class. I got scholarships to Northwestern University and the University of Chicago. So I had three scholarships and had to make a decision. Because Chicago was well-noted for its physics program and the fact that Enrico Fermi taught there, I decided to go there. My high school art teacher was quite annoyed at me for turning down my art scholarship.

Zierler:

Now did you know about Fermi even before you made that decision?

Friedman:

Oh yes, because it was right after World War II. I had known about the atomic bomb and read all about it and the fact that Fermi made such an enormous contribution. I read about the atomic pile they built and so on and so forth, so I said to myself, “If I really want to understand physics, I’d like to go to a school where somebody like Enrico Fermi teaches.” So I took that scholarship and never looked back.

Zierler:

Jerry, did you —

Friedman:

But it wasn’t easy because I didn't have any background. I didn't know trigonometry. I didn't know even what a cosine or a sine was when I started there. So it was an interesting venture because first of all, it was a very unusual university at that time. Robert Maynard Hutchins was the president.

Zierler:

Right.

Friedman:

And they had the Great Books courses in their undergraduate program, and the College was a very unusual place. You could either spend zero time and get a degree or spend four years and get a degree depending upon how you did in placement exams.

Zierler:

Right.

Friedman:

So I took the placements and I spent two years there, getting an AB degree. It was a wonderful experience because we read many Great Books, and there weren't any textbooks. Instead, there were just syllabi, and we would discuss all these Great Books. It was just a wonderful, wonderful experience for me. I had heard about all these great authors and these ideas, and here I was really reading them. It was so exciting. But then I started in the physics department after I’d gotten my degree, it was really hard because I didn't have a background in either physics or math.

Zierler:

So you didn't do any math and science during the liberal arts component of your education.

Friedman:

Only in the last year. I started taking analytical geometry and I then took calculus followed by differential equations during the time that I was finishing up. Then I started in the physics department, and the physics department was very tough at that time. The reason for it was that Fermi had the point of view that everybody should be admitted, even people like me with no background. There were some very hard courses and difficult examinations used to select students for PhD research. So I remember the first course I took, Physics 105, 6, and 7. We started out with about 125 people, and at the end of the year, only about 35 were left, and I was one of them.

Zierler:

Oh, wow.

Friedman:

What happened was really quite interesting. There was a test every Friday and the average score was about 50 out of 100. These were really hard tests. Often I would get a poor grade on these tests, and I would say to myself, “Well, you did poorly, but you don't know anything. What do you expect? You are learning,” so I wasn’t discouraged by it. Others who really came from better backgrounds and had higher expectations dropped out. Many students dropped out just for that reason. So it was because I had low expectations for myself that I didn't drop out and I finished. [Laughs]

Then after about a year there was another examination called a qualifying. Roughly 50% of the class failed out of the program, and then after another year there was the basic examination. Another 50% failed and left the program. I said to myself, “I made it!” I was so lucky. I wasn’t at the top of my class; I was of in the middle, but I said to myself, “I may not be the best student in the department but I’m going to try to work for the best professor.”

So I summoned up my courage and went to see Professor Fermi and asked him if he would accept me as his student. I thought he would ask me, “How did you do on the basic? How did you do on the qualifying? What’s your grade score?” Not a question. He said, “Come to my office on Monday. We’ll start you off.”

Zierler:

Oh, wow! That’s not what you were expecting.

Friedman:

Not what I was expecting at all. I felt as if I had won the lottery. [Laughs] And so I had the wonderful experience of working for this great man.

Zierler:

Jerry, I want to ask. When you had to gird yourself to go into him to ask if he would accept you as his student, was that more about your just deep respect for him and his stature, or was he an imposing individual and it was difficult to do something like that?

Friedman:

Well, let’s put it this way. He was obviously the best physicist on the faculty and clearly one of best in the world. He was perhaps the last physicist who was both an eminent theorist and first-class experimentalist. In addition, he was a wonderful teacher and was highly respected throughout the world for obvious reasons. So I said to myself, “Why not be inspired and taught by the best? That was really my motivation. I felt that somehow I could learn the most from him, and of course, I was fascinated by seeing how the great man approached problems. But I think it was really because of the qualities of the man and what he knew and what he could teach that really attracted me.

Zierler:

Jerry, I’m curious. Did you cross paths with Dick Garwin at this time?

Friedman:

No. Dick Garwin was gone. He left before I got to work on my PhD. He was a very imposing figure in the department, and it was sad that he left Chicago. But I think he had a run-in with Herb Anderson, and that’s why he left. I don't know the full story, but that’s what was said, because obviously he was somebody that Chicago should have kept.

Zierler:

Right. Right. So when you were starting your graduate program, I’m curious how well-defined your interests were in terms of the kinds of physics you wanted to pursue.

Friedman:

That’s a very good question, David. I always thought that particle physics was such fundamental approach to physics that I really wanted to understand it from that point of view. It is not that the other parts of physics aren’t important- they are very, important and very interesting; but I always wanted to understand the underlying laws and structure of matter.

Zierler:

Were you thinking more of approaching particle physics from a theoretical perspective or an experimental perspective?

Friedman:

Initially I wanted to be a theoretical physicist. But when I arrived in the department, I was part of a group that heard a lecture given by Fermi, and Fermi said to us, “In the next 20 to 30 years, the great developments in particle physics will be in experiment.” He advised us to go into experimental physics, and when a great man gave that advice, David, how could one say no? Most of us became experimentalists.

Zierler:

Now do you think he specifically had in mind all of the incredible advances in accelerator physics that were going to come online?

Friedman:

Well, that was part of it because, a few years before I started, Chicago had finished constructing a 450 MeV proton synchrocyclotron, which was the most energetic accelerator in the world at that time. That was, in those days, an incredibly high energy.

Zierler:

Right.

Friedman:

So this was going to open up the experimental development of particle physics and it did. One of the first great developments that happened there was that Fermi and others discovered the so-called the 3,3 resonance, the spin 3/2 positive pion-proton resonance. This was a revolutionary discovery that later became the first elements of the spin 3/2 SU(3) family. It was the beginning of the discoveries made at accelerators that led to unitary symmetry.

Zierler:

Right.

Friedman:

There were other particles that had been discovered that were not understood, such as K’s that had been discovered in the cosmic rays. This resonance was understood in the sense that its quantum numbers could be worked out, and that was why it was so important.

Zierler:

Jerry, I’m curious. As you started to work with Fermi, did you feel like you were in the middle of the physics universe? Did you have a sense of what was going on at places like Harvard and Caltech, or was Chicago as big as your world needed to be?

Friedman:

No, we would be informed about what was going on in the world of physics because there were many, many people who came and spoke at Chicago. The point was that everybody who came to Chicago wanted to talk to Fermi.

Zierler:

Right.

Friedman:

Very often, visitors would give private lectures to Fermi, and Fermi would invite his whole group. I saw Richard Feynman as a very young man when he came and gave Fermi a lecture - and also a number of other prominent physicists. So I saw many of the physics greats who came to see Fermi.

Zierler:

Right. Essentially Fermi was a magnet for the entire physics world.

Friedman:

Oh, yes. Everybody wanted to talk to Fermi.

Zierler:

Yeah. What was Fermi working on specifically during those years? What were his projects?

Friedman:

Well, he had many great interests, and he had worked on some aspects of cosmic rays. But I think his great interest at that point was to try to understand the interaction of pions with protons because I think that was the beginning of understanding the field of strong interactions. Of course, nobody understood strong interactions at that time, and many people thought it would be 50 years or 100 years before it because it was such a complicated thing. The strong interaction was too strong for perturbation theory to work, and nobody knew how to calculate without perturbation theory. A relativistic approximation that would take into account all effects was beyond reach, and so there was great uncertainty about when one would ever really understand the strong interaction. In a sense, the resonance Fermi discovered was one of the first steps on the path that ultimately led to the understanding of the strong interaction. As I said earlier, the Δ_3,3 resonance was the first member of the spin 3/2 SU(3) family that was discovered, and the structure of SU(3) gave rise to the quark model. And with the quark model you ended up with QCD, and the strong interaction was finally resolved. It took about 20 years after the discovery of the residence to solve the strong interaction problem.

Zierler:

Fermi had an appreciation of all of these fundamental developments that were coming online.

Friedman:

Oh, yes. He had a deep understanding of a wide range of physics. He a would try to understand surprising results that were observed at various accelerators. For example, it had been observed that when protons elastically scattered from carbon at, let’s say, 10 degrees they came out with a high degree of polarization. It turned out that he figured out why this happened. He had this famous idea about putting the LS coupling in the interaction, and if you put that in, you would get polarization.

Now it turned out he wanted to test this idea, so he gave me that as my thesis - to have polarized protons scatter elastically in nuclear emulsions and measure the right-left a symmetry. He ran the nuclear emulsion lab at Chicago at the time. He had calculated the expected results, but he never told me about this calculation. The objective was to find out whether it was really coming from elastic scattering or from inelastic scattering.

Zierler:

And by not telling you, that would independently give him reason to understand.

Friedman:

Yes, he didn't want to bias the results in any way. He was a very careful man. He gave me this assignment and I carried out this experiment. Unfortunately, Segrè at Berkeley scooped me before I was finished, and it turned out that his calculation was right on. He could have told me to abandon my experiment. But he knew that I had already put a great effort into it, and he kindly suggested that I continue with the objective of measuring whether there was any polarization in inelastic scattering. Sadly, he passed away before I finished my PhD thesis, and I was in great trouble because I had to find another faculty member who would take over my thesis.

Zierler:

Yeah. Those were some pretty big shoes to fill.

Friedman:

I asked a number of professors and they said, “Jerry, I’d be happy to have you work with me, but you’ve got to start something else. That’s not one of the problems I’m interested in.” I had already spent nearly two years on my thesis. But fortunately, there was a physicist by the name of John Marshall who said he would help me. I don't know whether you know of him.

Zierler:

Mm-hmm [yes].

Friedman:

He was a very nice gentleman. I went to see him and I asked him if he would take over my supervision and he said, “Sure! Finish your thesis, do a good job, and I’ll sign it.” I never really talked to him again except for his signing my thesis. So he really saved me, because otherwise it would have been a great problem. Who knows what would have happened.

Zierler:

Jerry, were you able ever to interact with Fermi on a personal level? I’m curious specifically if you would ever talk politics with him.

Friedman:

No, he may have talked politics; but only with personal friends.

Zierler:

Right, right.

Friedman:

He was a very nice man. I remember he invited me over to his home for events, and I remember the first time I was there. He took me around the room and introduced me to everybody; and I was just an incoming graduate student. It was a wonderful occasion. His wife, Laura, was a very elegant, lovely lady and couldn't have been nicer in her interactions with students. So that’s how I got to know him at a personal level, but never beyond that.

Zierler:

Do you know what his politics were? For example, Edward Teller, he wore his politics on his sleeve. Were you aware of what he thought about in terms of national security and the Cold War and things like that?

Friedman:

No. I never really discussed that with him and I don't really know. I think there’s a record out there in terms of his activities as a member of various committees, as part of the national advisory system,; but aside from that, I can't add anything to that because he would not discuss that with students. He possibly did with his colleagues, but with students, no. It was really all physics.

Zierler:

Now Jerry, after you defended, what were your aspirations? What did you want to do next?

Friedman:

I really wanted to continue doing research at a university. But I had a problem getting a job because John Marshall, who was very nice and signed my thesis, really couldn't write a strong letter.

Zierler:

Right.

Friedman:

I hadn't really worked with him, and there was nobody to write a strong letter for me. So I sent a letter off to various places and essentially got no responses. Chicago had a very nice arrangement that would allow students to become post-docs for about six or eight months while looking for a job. So I took advantage of that and continued in the emulsion lab. It was taken over by Valentine Telegdi, who was a young physicist in the department, and a very fine physicist.

What happened then was really quite interesting. It was 1956, and all kinds of new particles were being discovered and their decay schemes were being studied. There was one particle that decayed a in two different ways. But the problem was that these two decay schemes had different parities. Almost all physicists thought there had to be two different particles with the same mass, because it was thought that parity had to be conserved in the week interactions. So it was a very strange situation. Two young physicists who had worked with Fermi, but who were elsewhere, Lee and Yang, made the proposal that perhaps in the weak interaction, parity was not conserved. It was known at the time that parity was conserved in both the electromagnetic and strong interactions, but parity conservation had never been tested in the week interactions. Despite this, many physicists thought that the proposal by Lee and Yang was quite bizarre.

But Telegdi had an adventurous point of view. He said, “Let’s test this,” and he asked people in the laboratory to work with him; and nobody would do it except for myself, because they thought it was a fool’s errand to test parity conservation. I said to myself, “Well, It’s six months of my life, but it’s an interesting question to test,” so I did the experiment, carrying it out all by myself, and found out that parity was not conserved in the weak interaction.

It turned out that we were the third experiment to get this result. This helped me out enormously because Valentine Telegdi could write a letter to Bob Hofstadter at Stanford and get me a job.

Unfortunate circumstances prevented us from being the first experiment to have this result. What happened was that Val Telegdi had to go to Europe because his father had died; and he spent about three or four months there. In the meantime, I started getting results, but I only had one scanner at the time extracting data from the nuclear emulsion plates. I asked the person who took over the lab for Telegdi to give me another scanner so I could get more data as quickly as possible. He said, “That’s nonsense. My scanners are doing more important things. I can't give you one,” so I didn't get one. When Val came back, I told him about it and I had scanners immediately and we were able to get more data, but it was too late by that time.

I remember giving a talk before starting the measurement and describing what I was going to do. I remember a comment from Gregor Wentzel, who was a great and highly respected physicist and a very nice man. He came up to me. He said, “Hey, Jerry. That was a very nice talk, but you know you're not going to find anything.” So that was the general view about that experiment.

Zierler:

What did Telegdi see that you latched onto that everyone else missed? What was that?

Friedman:

Well, as I said, he was more adventurous. He said, “It’s a very interesting idea that hasn’t really been tested.” He supplied some crucial ideas in the planning stage, and I did the experiment. But it was his idea. I can't take credit for it. The only credit I can take is I had enough sense to be adventurous, and that I did the experiment correctly...

But at any rate, because of that, he could write a good letter for me to Bob Hofstadter, who hired me. So I went to Stanford and learned electron scattering.

Zierler:

Now, Jerry, I just want to interject right there. With nuclear emulsion, did you leave because you felt like most of the fundamental work there was concluded, or you just pursued new interests?

Friedman:

No. First of all, I was just happy to get a job anywhere.

Zierler:

Right. [Chuckles] Sure.

Friedman:

But I had heard about the electron linear accelerator at Stanford and that they were doing electron scattering from the proton in various nuclei, and I thought that would be an interesting thing to pursue. After all, my interest was in understanding the basic building blocks of matter and electron scattering was a very important technique in doing that.

Zierler:

What year was this when you got to Stanford?

Friedman:

1957.

Zierler:

So 1957 is pretty early on. Panofsky is not yet thinking about SLAC yet at this point.

Friedman:

Oh no, not at that time. So I worked there for three years, did various electron scattering experiments. I met Henry Kendall there. He was already working for Hofstadter when I arrived, and Henry and I established a partnership , doing experiments together, especially when Bob Hofstadter left for a year to go to Europe.

In 1959, Martin Deutsch visited Stanford. Martin Deutsch had been Henry Kendall’s PhD supervisor. He was a very well-respected physicist. He had done ground-breaking measurements of positronium. Henry of course met with him when he visited. I was with Henry, and Martin told us that MIT was looking for young people. He encouraged Henry and myself to apply, so we both applied and we got jobs at MIT! I came the very next year, and Henry spent another year at Stanford to finish his term of employment.

Zierler:

Did you give any thought to staying at Stanford? Was that an option for you?

Friedman:

No, it wasn’t an option. They sent away essentially all the post-docs at that time. It was very much like Harvard in those days.

Zierler:

Jerry, I’m curious if you felt specifically the impact of Sputnik on the job market, on the federal government’s support of science generally. Was that something that had an impact immediately to your life and circumstances?

Friedman:

Well, it may have because the fact that MIT hired a number of young people at that time probably was due to the fact that more money was coming in for research.

Zierler:

Yeah.

Friedman:

But I didn't make the connection, because I wasn’t thinking about it in that way.

Zierler:

When you were hired at MIT, how much were you on the job market? Were you looking at other positions, other opportunities?

Friedman:

No, at that point, it was just an opportunity that arose from a conversation - which we took advantage of. And it worked out, fortunately. [Chuckles]

Zierler:

What were your impressions when you arrived in Cambridge?

Friedman:

Well, MIT had an enormous physics department. There were numerous people who were very distinguished. I was so impressed and felt very tiny entering [chuckles] and said to myself, “I’ve got to work hard to make a place for myself here.”

Zierler:

So who were some of those larger-than-life figures on the faculty that made you feel tiny?

Friedman:

Oh, Viki Weisskopf, Herman Feshbach, Felix Villars, Francis Low and a number of gifted young people in theory. In experiment, there were Martin Deutsch, Bruno Rossi, Dave Frisch, Lou Osborne, and a number of upcoming younger people. MIT had a number of people who were really well-known in the physics community.

Zierler:

What kind of support did MIT give you in terms of resources for laboratories and research projects?

Friedman:

So that’s another interesting story. When I arrived, I had to join a group; because at that time, there was not the policy of having young people establish their own groups when they came in.

Zierler:

Right, right. And this, you came in on a tenure line, assistant professor?

Friedman:

Yes. So I joined Dave Ritson’s group and I worked with him for about six months. Then he went to Europe and never came back because when he was in Europe, he was hired by Stanford.! [Laughs] So suddenly, I had Dave Ritson’s group. I had three graduate students who were in the middle of their theses that I had to help finish up.

Zierler:

You got a crash course in being a graduate mentor.

Friedman:

That’s right, a crash course. So I did that. I started developing a program, and the program was at the CEA (the Cambridge Electron Accelerator). It was one of the reasons I thought MIT would be a great place because they also were going to have an electron accelerator, but it would be a synchrotron rather than a linear accelerator.

Zierler:

What was exciting about a synchrotron over a linear accelerator?

Friedman:

At that time, it was higher energy than was available at Stanford. Of course, ultimately, SLAC had higher energy than the CEA, but in those days, the CEA had a higher energy and that was desirable. The higher the energy, the smaller the distance that you probe. So you would like the energy to be as high as possible so that you can probe smaller and smaller distances in the system you're studying. So the 6 GeV that the Cambridge Electron Accelerator puvided was a great advantage over what was going on at Stanford in those days, which actually got to 1 GeV ultimately. But when I was there I think it was about 500 MeV. So the CEA was an opportunity to do more physics.

Henry came a year after me and joined me, so my group became our group. We started doing various experiments at the CEA and it was fine. But in our mind, the thing we really wanted to do was electron-proton scattering because the proton was a very, very puzzling system. You know, isotopic spin in was a big topic in those days. The proton and neutron are an isotopic doublet — twin particles except for charge, so to speak. But the question was why is the neutron heavier than the proton? It should be the other way around.

Zierler:

Right. How long had that question been asked?

Friedman:

For a long time.

Zierler:

How far back does that go?

Friedman:

I don't know exactly when it started, but it was a very, very perplexing question. Theorists tried all kinds of schemes to try to explain it, but it never really worked properly.

Zierler:

Is that because… Were theorists running into an experimental wall? In other words, was the instrumentation simply not there to allow the theorists the framework to understand what was going on?

Friedman:

No. They were using the wrong methodology in terms of theory. They were trying to utilize various effects to give the difference in mass. The fact that the proton has a positive charge, and the neutron has zero charge, in addition to whatever else is going on in these presumably twin particles, suggested the self-energy of the charge should have made the proton heavier; and yet the neutron was heavier. That was a very strange thing.

So to Henry and myself, probing the structure of the proton was always a matter of great interest. We wanted to du this at the CEA. However, we ran into a roadblock because the CEA had one good spectrometer with which you could do electron scattering, and Dick Wilson from Harvard was using it for electron-proton scattering. Since he was already doing electron-proton scattering, we decided to do electron — deuteron scattering to probe the simplest bound two-body nucleus. But there was no way we could get to use the spectrometer, even after he had made numerous measurements with it. He would not give it up - even though it was a laboratory instrument, supposedly available to everybody . It was essentially his. We tried every possible maneuver. We talked to people. We made numerous requests. Nothing worked, and we realized that we would be limited in what we could accomplish at the CEA.

At about this time, we heard that there were plans to build a very energetic electron linear accelerator at Stanford, I think it was about 1962 or 1963. Henry and I thought, “Maybe we could do our electron-proton scattering there.” We made contact with our old friends at Stanford and learned that we would be welcome to participate in this project.

Zierler:

Who is “we”? Who are the key collaborators in this work?

Friedman:

Henry Kendall and myself, and then our group. But the question was how does an MIT professor who has to teach do research 3,000 miles away?

Zierler:

Right. [Laughs]

Friedman:

That was a big question, an enormous question. Henry and I discussed it and we couldn't resolve it.

Zierler:

What were your teaching expectations? Were you on a 2:2, a 3:3?

Friedman:

It was a two-semester teaching program, and we had to teach each semester. The summer would be free, but the fall-winter semester and then the winter-spring semester had to be covered.

Zierler:

Now are you tenured at this point?

Friedman:

No.

Zierler:

So a sabbatical is sort of a bit too… That’s not happening.

Friedman:

No. First of all, we weren't there long enough for a sabbatical, which is after six years. We were also junior faculty. Henry came as an associate professor — I was an assistant professor — because Henry had more experience at that point. So we went to see the head of the physics department, Bill Buchner, who was a very nice man. We told him our dilemma, expecting essentially that there was no possible resolution to this problem. But Bill said, after he heard us, , “Henry and Jerry, no problem. You two will teach one course, and when Henry is away for two weeks, Jerry, you’ll teach. Then you can go there for two weeks and he’ll teach.”

Zierler:

Oh, wow.

Friedman:

With no requirements of making up the teaching at another time.

Zierler:

Now Jerry, is your sense that… I mean this is a remarkable arrangement for the head of the department to make for these two young professors. Is your sense, reading ahead a little bit, that he appreciated how fundamentally important this work was and that he needed to give you this kind of accommodation to make it happen?

Friedman:

I’ll tell you, David, it’s hard to know what goes on in somebody else’s mind, so I really don't know.

Zierler:

Right.

Friedman:

But that’s very possible. But the other thing about it is that MIT has a flexibility that other universities at that time did not have. I don't think we could have done this at any other university. My impression was that at MIT, if you tell administrators what you're up to and it’s a good idea, they’ll find a way for you to do it. That’s my impression about MIT. It has always been my impression. So, we a started a group out at Stanford. I think it was the first very distant high energy group in the country. For example, Columbia had a high energy group at Brookhaven, but that’s within a day’s drive That’s not that far away. But 3,000 miles away is something else.

Zierler:

Yeah.

Friedman:

So for a number of years, Henry and I both travelled back and forth to Stanford, spent two weeks there and came back and taught. We would change places, and we slowly built up a group there. It was a pretty formidable group. We participated in helping design the equipment, the big spectrometers and the electronics, and we also built the hodoscope detector. We also did a lot of the calculations for preparing the experiment — preparing the radiative corrections for the analysis of the data, and then participated in the program at SLAC.

Zierler:

Jerry, did you ever think about or talk to Pief about simply joining the faculty at SLAC? Did that ever cross your mind?

Friedman:

No, it didn't cross our minds, but it turned out that both Henry and I were offered jobs at SLAC, on the SLAC faculty — not in the Physics Department. We didn't want to leave MIT. MIT was too interesting a place.

Zierler:

It was worth the schlep to do this.

Friedman:

It was worth the schlep, and I’ve never regretted it because MIT is such an exciting place.

Zierler:

Sure.

Friedman:

At MIT, there are so many things that are happening outside of particle physics; in so many different fields and so many different areas, and you can meet such interesting people. Now, of course, Stanford is also a great university. But at that time, there was a rift between the SLAC faculty and the Stanford physics faculty that soured relations and interactions between them.

Zierler:

Yeah. Now who were some of the key collaborators that you had at SLAC who were on the SLAC faculty?

Friedman:

Well, there were Dick Taylor and Hobey DeStaebler. They were the two primary ones, and there were some young post-docs like David Coward. So those were the people that we mostly interacted with.

Zierler:

In this group, Jerry, was there a basic division of labor based on every individual’s field of expertise and interest, or was everybody sort of jumping in; it was an all-hands-on-deck kind of situation?

Friedman:

There was a division of labor to a great extent. The SLAC group under Dick Taylor supervised the building and calibration of the spectrometers. Henry overlooked and supervised the construction of the hodoscope, and its electronics. I did a lot of work in preparing the analysis and the radiative corrections. It is important to mention that physicist from Caltech joined us in these efforts, taking on various responsibilities in preparing the equipment.

Zierler:

Jerry, I’m so curious. In these fundamental episodes of discoveries, as you're building the instrumentation, are the research questions you're asking, do those change over time? Or do you build the instrumentation with the pre-ordained question already there so that the instrumentation is designed to answer that question? Can you explain that interplay?

Friedman:

That’s a very interesting question, David. I think as an experimentalist, you build equipment for a range of possibilities. You don't have a preconceived idea of what you're going to find because if you do, you can limit what can be discovered and it can possibly bias what you think you're observing.

Zierler:

Right.

Friedman:

When we started, we were not looking for quarks. The quark model had been developed in 1964. This resulted in many searches for quarks at accelerators and in nature, but no quarks were found. There were other issues that made the quark model questionable. Quarks have fractional electric charges, but all particles that had been found in nature have integral charges. In addition, quarks were supposed to be point-like particles, with an associated field theory. But field theory could not really be used for these point-like particles because their presumed strong interaction coupling constant was too large to use perturbation theory. Actually, perturbation theory is now used with the strong interaction at very high energies, but that’s another story that I’ll get to later. But at that time there was great skepticism about the court model in the physics community.

But when we started, the idea was just to examine the inside of the proton with electrons and see what we could find. We didn't know what we were going to find. Our first attempt was to do elastic scattering.

Zierler:

Elastic, not inelastic.

Friedman:

Not inelastic because probing with elastic scattering was the standard approach at that time.

Zierler:

Right, right.

Friedman:

We did a very nice measurement of elastic scattering. It went out to large momentum transfers, but we found nothing new. We found the same form factor that had been found at CEA and DESY at lower energies. So we didn't learn anything new and it was very disappointing.

Zierler:

And Feynman would come up and pay attention to what was going on.

Friedman:

Not at that time.

Zierler:

This was too early.

Friedman:

Yes, it was too early. I’ll tell you about Feynman later. But as mentioned, it was a group of experimentalists Jerry Pine, Barry Barrish and others, who came from Caltech and participated in the elastic scattering experiment; and I should point out that they did important work also in developing the apparatus and constructing it. After we saw the elastic scattering results, we were all very, very disappointed because we thought that we would have seen some sort of change from what was going on at lower energies that would give an indication of something that we didn't expect. Well, we didn’t, and so what happened was that Henry, Dick, and myself thought about it and we decided that why not look at inelastic scattering? That didn't go over very well.

Zierler:

Jerry, I just want to interject here. The verbiage, it just sounds like the opposite — elastic, inelastic. Can you explain scientifically if it’s really 180-degree change of direction?

Friedman:

Yes. In elastic scattering, the proton is unchanged except for its energy and its momentum after the electron scatters from it. In inelastic scattering the proton is shattered, producing other particles. So that’s the major difference.

Zierler:

Okay.

Friedman:

At that time, the prejudice was that elastic scattering was obviously the only method that would be useful because the proton stays intact and you can use the measured form factor to tell you something about the proton’s structure. But there’s a sequel to the story that I’ll tell you about in a short time. So when we decided to try out inelastic scattering, the program committee wasn’t very happy. Caltech thought it was a waste of time and they dropped out. Henry, Dick, and myself made this proposal to the program committee and they had a very negative response. They would have turned us down, except that Panofsky, with his great influence got the program committee to accept our proposal. But this acceptance came with the directive that we concentrate on measuring the inelastic residences rather than the in elastic continuum, which was what we really wanted to explore.

In the meantime, I talked to some theorists and asked them if they would calculate what we could expect in inelastic scattering, what the spectrum would look like, and they said it was a waste of time. They wouldn't bother.

Zierler:

Why possibly would they say it was a waste of time?

Friedman:

Because it’s too complicated. You have all these particles coming off in inelastic scattering. So many processes take place and the kinematics so varied. What could you possibly learn? I took the point of view, well, we can make an approximation. Fermi had shown us by example how to make such approximations. He could approximate anything. He once approximated the Lamb shift in three lines and got the answer to 15%. So I made a set of approximations of what to expect in the continuum, that included radiative corrections. This approximation was based on what I called the old model of the proton, not on a model in which the proton has point — like constituents.

We started making the measurements and looking at the spectrum. As we did the measurements, we noticed that the elastic peak and the resonances all decreased very rapidly with increasing four-momentum transfer squared. But the broad spectrum of the inelastic scattering did not.

Comparing this with my approximation, first we found that the results were about a factor of 2 greater than the approximation. Well, it’s only an approximation; so okay. With increasing energies and momentum transfers, the measurements were greater by a factor of 5, it’s still probably the approximation. Then a factor of 10 greater, a factor of 100 greater, and later a factor of 1,000 greater; and it became quite clear that something new was happening in this scattering process. We brought this to the attention of the program committee and Panofsky, and we got as much running time as we wanted. We were able to carry on the program from about 1967 to about 1973 or so.

Zierler:

Jerry, looking back, how important was it to have Panofsky’s support for this research?

Friedman:

Very important. I think we probably couldn't have done it if he hadn't given us the political support that we needed. I also have to give credit to a young physicist, who had at the time just received his Ph.D, James Bjorken. His prediction of scaling, that we were able to confirm early in our work also created enormous interest in our experiment.

Zierler:

Yeah.

Friedman:

Bjorken did theoretical work that suggested that important physics could be extracted from the inelastic spectrum. He developed sum rules that could be used to extract this information. So I think the combination of Panofsky and Bjorken’s work helped us get our running time.

You might ask why I was so interested in inelastic scattering? One of the things I had done while working for Hofstadter — and I did this alone, without any collaborators — was that I tested a sum rule that was developed by Drell and Schwartz, which said that if you scatter from the deuteron and you look at the inelastic spectrum and you sum over all states, you can get information about the ground state. So I did that experiment, and it suggested to me that the inelastic spectrum does have information about the ground state of any system. I didn't know what we would find with the proton, but it suggested to me that it was worth looking in that direction.

Later, about a year after we started, Richard Feynman’s parton model provided a plausible picture of the physics of what we were observing in our measurements- in fact, his picture made it obvious. In the model, the proton is made up of point like particles called partons. In inelastic scattering, the electron scatters from a single parton, and the recoiling parton interacts with the other partons, creating other particles. Because the partons are point-like, the inelastic cross-section does not rapidly decrease with four momentum transfer.

Zierler:

Now when you say he made it look obvious, in what way?

Friedman:

I should go back to something called scaling. Bjorken made this very important discovery that you would get scaling at high momentum transfers and high energies in the inelastic spectrum. Scaling predicted that the structure functions extracted from the cross-sections would not depend on two relativistic invariants independently; and they would only depend upon the ratio of these two invariants.

And of course, we checked to see if our measurements obeyed scaling and we found scaling within the statistical errors. In Feynman’s parton model, Bjorken’s scaling variable came out automatically and was the inverse of the fraction of the proton’s momentum carried by the parton that was scattered by the electron. And you knew exactly what scaling meant.

But in addition, Feynman showed something that was not obvious at the time, which was that you could never uncover substructure in the proton with elastic scattering. This is because, in elastic scattering, the interaction occurs over a long period of time, compared to inelastic scattering when there is a large exchange of energy. This can be seen from the uncertainty principle

In inelastic scattering, with a large transfer of energy, the interaction occurs over a very tiny interval of time. This makes it possible to see individual constituents in the proton even though they are moving very rapidly. It’s like taking a photo of a moving object with a very fast shutter speed. Elastic scattering corresponds to a very slow shutter speed; and consequently, you will only measure a charge distribution rather than see individual constituents. I don't know whether I have made this clear to you.

Zierler:

Sure. Absolutely.

Friedman:

But that’s what Feynman showed, and I think that that was extremely, important. We never would have learned much with elastic scattering.

Zierler:

Right.

Friedman:

So I think when you come right down to it, both Bjorken and Feynman made enormously important contributions to resolving what was going on. By about 1968, we already knew there were likely point-like objects in the proton, and the question was, Were they quarks? There were two things that one had to show: that they were spin ½ and they had the fractional charges of quarks. By doing small-angle and large-angle scattering and taking their ratios, we found out that these were spin ½ constituents. Determining whether these constituents had the fractional charges of quarks required using neutrino data from Gargamelle, a large heavy liquid bubble chamber at CERN. So if you compared the structure functions from neutrino scattering and those from electron scattering, the ratio would depend on the charges of the constituents. That ratio showed that the quark model was right on.

That was in 1972 that these results were first presented at a high energy meeting at Fermilab by Don Perkins, who was a member of the Gargamelle group. And after that, the quark model had to be accepted by the physics community, though some skeptics remained who had to be convinced by later experiments. Then about a year later came QCD. Looking at our results and the fact that the constituents of the nucleon appeared to interact as free particles in our experiments, made it quite clear that QCD was the only model that would fit all the experimental results.

Zierler:

Now Jerry, smack in the middle of all this, string theory happens. I’m curious if you were paying attention at all to that.

Friedman:

No, not really. It’s a very interesting approach, but it’s of the order of 15 orders of magnitude of energy beyond what even CERN can produce. In other words, it’s a theory at the Planck scale which is so high in energy that to make it apply in any way, you have to extrapolate 15 orders of magnitude down, and there’s just no way of doing that.

Zierler:

Experimentally, you mean.

Friedman:

Experimentally. Absolutely. So I think it’s an important development in terms of trying to understand the structure of theories. I don't think it had any relevance to what we were doing.

Zierler:

Jerry, at what point during these years — you know, you're looking at 1968 to 1972. Are there particular days or moments when you say you’ve really landed on something here and it’s time to write a paper? How do you decide when to publicize your findings?

Friedman:

As we got the results, we published them sequentially. It wasn’t as though we waited till the very end and wrote a big paper. We did write a summary paper in 1974, but during the discovery period, every time we got results that we considered new, we thought we should publish them just to alert the community for them to think about it.

Zierler:

Right, right.

Friedman:

By about 1968, there was a suspicion, a very strong suspicion, that there were point-like objects in the proton, and let me tell you about my experience of how that went over. I was the one who went to the Vienna conference to give the first results of the experiment in 1968. Before I went to the meeting, we had a group meeting, which was to decide what I should say at this conference. There were some of us who thought that I should indicate that the results very strongly suggested point-like objects in the proton. Part of the group said, “No, that’s too extreme. It’s so far from the current point of view that people will think we have bizarre thinking.” We took a vote and those of us who wanted to talk about the point-like structure lost.

So I went there and gave the presentation, and I didn't say a word about the possibility of point-like structure. Panofsky gave the plenary talk, and he said, “There are suggestions in the data that there is possibly point-like structure in the proton,” So he did say it. But it went over very poorly because it was like dropping a stone in water — a couple of ripples and then the water is flat again. Nobody ever came to ask me about it or discuss it, so the community wasn’t really ready for that point of view in 1968.

Then as time went on and we got more and more data, more people started taking these results seriously. When in 1972, Don Perkins gave the results at Fermilab about the ratio of the structure functions, pointing out that the point-like objects in the proton and neutron have charges consistent with those of quarks, physicists began taking the idea of point like structure in hadrons even more seriously, and started accepting the validity of the quark model. Within experimental errors, the quark model had been confirmed, and that was it. As you know, as in every experimental result, the ratio had an experimental error; and by the next year, the error got smaller ; and the results became even more convincing. I think at that point, most people could not escape the quark model. Then after that, many physicists started thinking about the quark model as a very fundamental part of particle physics. Then came QCD. QCD introduced asymptotic freedom, which has the strong interaction decreasing with increasing energy. So the asymptotic freedom aspect explained why when you did high-energy scattering from the nucleon, it looked like there were no interactions between its point-like constituents. It all came together, and now we have the Standard Model.

Zierler:

When you say it all came together, intellectually theorists and experimentalists were really relying on each other.

Friedman:

That’s right. Exactly.

Zierler:

Who were some of the theorists who were most important to you intellectually or as…not as collaborators in the laboratory, obviously, but working through what all of this means?

Friedman:

That would be probably Bjorken, and of course Feynman. who would come and give lectures. Those two, I think, were the ones who were the most influential to the group.

Zierler:

Jerry, you said before it was important for you to maintain your tenure, your affiliation at MIT, right? It was worth it to go back and forth. So I’m curious specifically in what ways would it be valuable for you to take a break from the research at SLAC and go back and teach and discuss what you were finding with your colleagues back at MIT.

Friedman:

It was invaluable, because I could talk to my colleagues, and spend time with them chatting about the physics. I talked to Viki Weisskopf, and Francis Low, and they always had some wonderful insights about what we were doing. In fact, Viki made one of the first realistic models of how to a incorporate quarks into a complete model of the proton, and was the first to incorporate gluons into the model. Kenny Johnson and Bob Jaffe worked to develop the bag model, which was another approach to approximate the proton.

Zierler:

In what ways had your teaching changed over the course of these years based on what you were learning and doing the experiments on at SLAC?

Friedman:

Well, that’s a good question. First of all, most of my teaching was at the undergraduate level.

Zierler:

Right.

Friedman:

So at MIT, I did teach particle physics once or twice, but it was before I started my work at SLAC. I also taught special relativity a number of times, but most of my teaching was undergraduate electricity and magnetism and mechanics. Because MIT has about 1000 incoming students, and at that time all freshman had to take a year of physics, most of the physics faculty taught undergraduate courses.

Zierler:

At what point, Jerry, with this project at SLAC did you know that… You know, I mean the discovery never ends, but when do you know how to close out a particular research endeavor? When do you know you figured out what you needed to figure out and now it’s time to move on to new pursuits?

Friedman:

Well, what happened was that Fermilab was coming into operation, and they were planning to do neutrino and muon scattering to look at the same kind of phenomena as we had been studying, and they had much higher energies. It became quite clear that they could learn more than we could continuing at SLAC. So by about 1973, ’74 it was apparent to us that our program was really over at SLAC

Zierler:

Did you see a need for higher energies after SLAC?

Friedman:

Oh, yes. In particle physics you always see a need for higher energies. The higher the energy you have, the smaller the scale you can investigate. As you know, we have the Standard Model today, and it is a wonderful model. It seems to explain all the processes we can observe at current accelerator energies. At this point, CERN has not found any deviations, or if they have, they’re still questionable. However, we think that at higher energies we will very likely find new physics. The Standard Model is an enormous achievement in physics but it is generally thought that it raises a number of perplexing issues that pose open questions. The general point of view is that the Standard Model is certainly not complete and that there are additional phenomena that are yet to be discovered, which would add to or change the Standard Model.

Zierler:

Jerry, based on this, were you ever involved in broader efforts to build laboratories to operate at higher energies like the SSC?

Friedman:

Yes. I was the chair of the Scientific Policy Committee at the SSC, so I was helping to plan the laboratory in various ways until it was terminated.

Zierler:

When did you first get involved in that? Would that have been early on, like 1983, 1984?

Friedman:

It was after Roy Schwitters was chosen to lead the project. He asked me to do that, but I can't remember the exact date that that occurred.

Zierler:

What were some of your responsibilities in that role?

Friedman:

Well, the responsibilities were to try to understand the range of scientific programs that should be carried out. And there were many questions coming up with regard to how things would be done. We discussed how groups of physicists would use the machine and how these groups would be set up and what facilities would be needed. For example, you would want to have 4π detectors, but you would also want to have other detectors, single-purpose detectors as they have at CERN, as well as extracted beams. I can't remember all the questions because it was some time it ago — about 30 years ago.

Zierler:

Right. [Chuckles]

Friedman:

So you're testing my memory, unfortunately, which is not as good as it used to be.

Zierler:

You probably remember —

Friedman:

But there were so many different scientific and organizational questions that came up. For example, this machine was going to have a circumference of about 56 miles. Do you have separate laboratories set up? How do you efficiently transfer people and equipment from one end of the machine to the other? You’ll have detectors at different places very far apart. So there was a big set of questions. It was territory the likes of which we’d never entered before.

Zierler:

From your point of view, what was lost by the SSC not being constructed?

Friedman:

First of all, it was a tremendous loss for science. The SSC was planned to have an energy about three times greater than that of the LHC and would have permitted a much greater exploration of the physics. I think what was additionally lost was the full engagement of American scientists. it’s true we’re doing pretty well in terms of working at CERN. The American contingent there is doing very well there and are very effective. But we’d have more people and especially more young people involved in the SSC. Not everybody wants to go and spend months at a time in Europe. I think we would be closer to the science with the SSC. And with the SSC, we would be saying to the public that the US is still a leader in science. It would have said that we are still able to do things that nobody else can do, and I think we’ve given that up. We’ve really given that up. There are so many young people who would have been involved who are not involved; and of course, that has a ripple effect all through society because these young people would get trained on it and go off and do all kinds of things in society. And we would have much more technology development in the US. I think it was just a great loss in opportunity. You know, it’s probably the most sophisticated scientific instrument in the world that we would have built. We would have trained people in ways that they could not be trained elsewhere. We would haved develop technology that could not be developed elsewhere. We would have gotten results that would have inspire young people to go into science, and go into other areas in addition to particle physics. It’s a terrible loss.

Zierler:

In happier news, Jerry, I wonder if you can talk a little bit about your time as Director of the Laboratory for Nuclear Science at MIT.

Friedman:

Well, it was an interesting time. The one thing that was nice about being the director of a laboratory is that you get to understand all the things that are going on there, maybe not as deeply as the people who are doing the projects, but at least enough to give you satisfaction. So what I really enjoyed is learning about all the various scientific projects going on. I really felt as though it was a privilege to be there, and I liked the idea that I could help other people solve problems that were giving them difficulty and help advance scientific projects. Also, it was the first time I started learning about how to deal with Washington and learning about the politics of science which I hadn't really spent much time doing.

Zierler:

Mm-hmm [yes]. What was that connection between the Laboratory and Washington DC?

Friedman:

Well, the Laboratory was supported through the Department of Energy. I would go to Washington on occasion and DOE people would come to the Laboratory. We would talk about our projects, discussing their progress and needs. We would also talk about how to develop proposals and how to make them successful and what issues are important for influencing political leaders to make the right decisions about support for the field. It became clear to me that scientist don’t always have the correct approach in influencing political leaders. So it was all quite an educational experience, and there was a feeling of great satisfaction in seeing the accomplishments of our laboratory projects.

Zierler:

What were some of those great achievements under your tenure?

Friedman:

I’m trying to remember. Unfortunately, I really can’t remember. It was 40 years ago; and sadly at this age, my memory has become somewhat poor. We had exciting projects going on at Fermilab and DESY, but I can’t remember exactly what achievements occurred in the three years that I served as director of the Laboratory. It was only three years that I served; and the reason it was three years was because I was asked to be head of the physics department, and I was asked in a way in which I couldn't say no. [Laughter]

Zierler:

What about as chair? What opportunities did you see to improve the department of physics at MIT in that capacity?

Friedman:

Okay. What I tried to do was to set up committees in which there was broad participation. For example, when I started, there were ad hoc education committees, and what I did was set up a permanent standing education committee that looked over the curriculum every year. The MIT Physics Department has a structure that was very helpful. We have four different divisions: theoretical, condensed matter, particle and nuclear, and atomic. The Division Heads represented the various faculty who did research in these areas. But that was developed before I came, and the reason for this structure is that the department is so large. I think when I was Head, there were close to 80 faculty members in the department and a number of adjunct people.

We had wonderful discussions about what sort of specialty courses should be given and about faculty searches. I interacted with the laboratory directors also to try to make sure that there was a unified voice between the department and the laboratories in terms of supporting faculty and their research projects. And my responsibility was to make sure that good people were put in the positions of leading these divisions, because they were almost like assistant department heads dealing with the people in their divisions, representing what their needs were and what their concerns were, etc. So that was a very big part of my position. I was very happy that Bob Birgeneau was one of the first people I picked, to represent condensed matter; and as you well know, he did very well administratively. He rose to Department Head when I stepped down. I wasn’t somebody who was really enamored of being an administrator, so I stayed as long as I felt I should. Then later he became Dean of Science, so he rose like a rocket. [Laughs]

Zierler:

Now Jerry, during this time, I’m always curious how these things happen. First, I’m curious about the long gestation period between research and when the Nobel committee recognizes the research, right? So it’s a good 16 years plus between your time at SLAC and the Nobel award in 1990. How do you… I mean, do you just put these things out of your mind? Is there a buzz that happens where you think that this could be the year? I mean, how do you deal with these things?

Friedman:

Let me tell you my perception of this whole thing. When I was at a meeting at the University of Wisconsin — I think it was in mid- or late ’70s; I was approached by a Swedish physicist who said he was teaching a course in the history of physics and he wanted to know about our experiment at SLAC. He wanted to know who did what and so on and so forth, who was responsible, etc., etc. So I gave him the information that I thought was relevant and correct. This person also approached Henry with the same set of questions. So he and I both thought that possibly this was someone from the Nobel committee trying to do their research. However, when the time came for the announcements, nothing occurred which involved us, so we just said, “Well, it didn't happen. It’s not going to happen,” and I really didn't think about it after that. It just went from my mind.

In fact, when it was announced in 1990, I was at a meeting in Fort Worth, Texas for the SSC, and the night before the announcement, we were all discussing who would be announced the next day; and nobody in the group brought up Henry and myself, or anybody else associated with our experiment. So that was the point of view. We had just stopped thinking about it, and I was so amazed when I learned about it the next morning. It was 5:30 in the morning and my wife calls me. I answered the phone with some concern because my elderly mother was living with us at the time. And my wife says, “Jerry, this isn’t bad news,” and she told me me about it. I really couldn't believe it. I wondered if I was still dreaming? [Laughter]

Then what happened was that shortly after that, I got a series of phone calls. One was from WBBM in Chicago, with a live interview. The first thing they asked: “What will you do with the money?” [Laughing] That’s the first question they asked me! And the calls kept coming. So at some point I realized that I had to get dressed and get downstairs. There were things I had to do so I asked the operator in the hotel to take my messages and went downstairs.

As soon as I got off the elevator, somebody walked up to me and said, “You're going to have a press conference in 15 minutes.” So I go into this big room and there are lots of big lights around and a large number of people already sitting there. There was an hour discussion and questions from reporters. The one good thing that resulted from this was that I got $50 million for the SSC because of something I said.

Zierler:

Which was what?

Friedman:

I said that the SSC was short of money at this point and needed money to do such-and-such, and apparently the money came the very next day. So that was the most effective I’ve ever been at securing money for a scientific project. [Laughs]

Zierler:

Mm-hmm [yes]! Jerry, on that point, I’m always curious. The Nobel Prize accords a platform just as you described, right, just in this one moment. It accords scientists who receive it a certain platform where they now have a voice that reverberates far beyond the area of research for which they were recognized.

Friedman:

Correct.

Zierler:

You know, that creates both opportunities and also pitfalls, and so I’m curious, in the past 30 years, how you have decided when to use that platform and when not to use that platform.

Friedman:

Well, it’s a matter of judgment, David. You have to figure out whether the cause is worthwhile and important and whether you can be effective. Those two things have to come into that decision, and I try to do the best I can in this regard. I’ve signed many, many letters and opened letters from Nobel Laureates for various issues and causes in both science and politics. I helped develop a new university in Okinawa. I’m sure I wouldn't have been influential in this venture without the Nobel Prize. It’s the Okinawa Institute of Science and Technology. I helped establish an international forum in Kyoto. It’s the STS forum. Of course, I did this with many other people, but the point is I was part of the team to do this because I had a Nobel Prize; and I’m sure I wouldn't have been involved otherwise. So there are lots of good things you can do, and that’s been one of the great benefits of having a Nobel Prize.

Zierler:

Now in recounting the research during these formative years at SLAC, you're very generous in demonstrating that there were a lot more people who were involved in the project than the three individuals who were recognized with the award, right?

Friedman:

Oh, absolutely! The experiment was a group effort, and all the participants made very important contributions. David, science is a collective activity.

Zierler:

Exactly.

Friedman:

So Henry, Dick, and myself were leaders in it. We couldn't have done this experiment without the participation of all these other people who made essential contributions!

Zierler:

Right, right.

Friedman:

Recently we had a 50th anniversary of the discovery of quarks at MIT, and I insisted that all the talks be given by the graduate students who did wonderful work during this program. They never got the credit they deserve; and as far as I’m concerned, I would have been happy had the Nobel Prize been for the group rather than three of us, because I think the whole group deserved such recognition. But unfortunately, the rules don’t permit that

Zierler:

Right, right, and that’s exactly what I was going to ask you. You know, fortunately, you didn't have to choose yourself for this recognition; someone else did that for you, right? But it sounds like if you had your own druthers, it’s really problematic that they single out individuals when in fact —

Friedman:

Absolutely, absolutely! In fact, let me tell you how we felt about this. One of the things that Henry, Dick, and I did, because we understood this and all felt this way, wss that we made sure that everybody who was involved could come to Stockholm for the Nobel ceremony. Our whole group was there, and it was a wonderful occasion. That was the way to show the recognition that they truly deserved. As I said, as far as I’m concerned, it would have been ideal if the Nobel Prize had gone to the group instead of to three individuals. But the rules don't permit that.

Zierler:

Jerry, I wonder in what ways — I mean, you're a mild-mannered physicist. You're just trying to do good work in the laboratory, and so I wonder in what ways did this level of recognition enhance your career and allow you opportunities in research and experimentation that you might not otherwise have had, and in what ways did it sort of serve as a distraction and it was difficult for you to continue in that kind of work?

Friedman:

Well, I’ll tell you. I got the Nobel Prize when I was 60 years old, and by that time I wasn’t as active in research as I had been in the past, primarily to some extent because I got involved in this administrative work; and it’s really hard to get back in. But I was slowly doing that, and then of course the Nobel Prize came. Then, of course, when that came, it was positive in terms of what I could do for the community and for science. It was to some extent negative in terms of my pursuing research because when you have this kind of responsibility, it’s really important that you take it. You can do some good things. In a certain sense, the research is one area in which you can do good, but the truth of the matter is that the research will be done by others if you don't do it. But you do have a certain responsibility in helping both science and society as much as you can, using the position of a Nobel Prize winner. So there’s a responsibility that one has to do some good with it. Otherwise, what’s the point? What’s the point, just to be admired? No. So I think you have to make a choice, and I think many have made that choice.

Zierler:

So Jerry, what would be a great example of you doing essentially that, utilizing this recognition to in turn help other up-and-coming researchers in the field?

Friedman:

By trying to be influential with political people. For example, when the SSC was in political trouble, I spent a great deal of time in Washington talking to senators. We had lost the vote in the House by a large amount; and after that, I went to Washington periodically, very often to talk to senators. In fact, before the vote in the Senate, I spoke to 25 senators about the SSC. In the Senate vote, we won! I think it was about 63 to 34 to continue construction. And I had also spoken to many people in the House before their vote, but we lost badly in the House. I remember, I often made these visits with Steve Weinberg. But unfortunately, the bill was killed in the house — Senate conference committee because the losing margin in the House was too large. And, sadly, the SSC was lost. But that was one of the ways I tried to use whatever influence I had.

Then when I was asked to help in Japan, I helped plan and establish an international university. The university in Okinawa is very unusual. It was the idea of a powerful political leader by the name of Koji Omi, Who was then Minister of Science and Technology and later served as Finance Minister. He wanted to do something totally new. It is an international university in Japan, multi-disciplinary, and all classes and discussion in English. By law at least half the faculty and the students are non-Japanese. So over the years I helped establish it. I started in 2001, and I’m still on the board of that university. I consider it a privilege to have had the opportunity to work on this project. It officially opened its doors in 2011 and is still growing. It has been a very satisfying experience, especially with the knowledge that this university will not only be a great asset to Japan, but to the world.

Zierler:

Right.

Friedman:

The University is already doing world-class research and is attracting outstanding faculty and students from Japan and abroad. International collaborations have been established. The students who are being trained there will end up all over the world

Friedman:

So it’s things like that that have moved me and made me get involved. And in addition, I worked with Koji Omi to help set up the STS forum. It is a forum on science and technology in society, and its objective is to promote the use of science and technology for the benefit of society. So those are the kinds of things that one can get involved with if one has a Nobel Prize; and that’s what makes it so valuable.

Zierler:

Well, Jerry, at this point in our discussion, I’d like to ask you some sort of broadly retrospective questions about your life and career, and then maybe we can end on sort of a future-facing question about what you see as some of the prospects in your field going forward. So first, I’d like to go back all the way to the beginning, essentially, and I wonder if you can think a little bit about how some of your artistic talents and interests might have been useful in your development intellectually and experimentally as a physicist.

Friedman:

Now that’s a very interesting question, and I’ve thought about that. I think that because of my background in art, I think in pictures. There are people who probably think in mathematical formulas, but I don't think about things mathematically. I think of things visually, and I think that’s been helpful in terms of trying to understand how things work. For example, in a certain sense, the experiment we did was the equivalent of using a very high-powered electron microscope to investigate the inside of the proton; and of course, if you use a microscope, you see things. That’s the way I think of things, and I think for this particular research, it was very valuable.

The other thing about art which I think is very important in terms of doing science is that in science one has to think intuitively when developing something new, just as an artist does. You know, all kinds of different images and thoughts come together in your head and you think of different possibilities. Now in art, you can express all these possibilities however you want, expressing your creativity; and this creativity may resonate with other people or not. But in science, these intuitive possibilities have to conform to nature. But in the origin of the ideas, they come just as they do in art, and I think that’s where there’s a tremendous similarity. The dissimilarity between science and art is what the actual test is of these ideas.

When de Broglie proposed that particles could behave like waves, he must have had that same kind of experience, thinking about it and saying, “Well, if you can have waves that behave like particles, as Einstein said in 1905, why can't you have particles behave like waves?” That kind of thinking is a product of your intuition. But of course, de Broglie’s idea had to be tested; and when it was tested, it was found to be correct in electron diffraction experiments. Then this was further confirmed by the success of quantum mechanics. I think art is important in one’s education. Art loosens the mind to accept more possibilities in thinking.

Zierler:

Jerry, there is no doubt working with the people that you did and where you did at places like MIT and SLAC in the 1960s and ’70s — there’s no doubt that you were operating right smack in the middle of a golden age in particle physics, right?

Friedman:

Absolutely.

Zierler:

A golden age, though, does sort of suggest that there are ebbs and flows to these things, right, and perhaps now you might see that there is not as much fundamental work being done in this field. Would you agree with that?

Friedman:

No, I wouldn't put it that way. I think the work that’s being done is as fundamental; I think it’s harder because when you have a very good theory, then it’s hard to improve upon it. But we know that it’s incomplete. The real problem is it’s the old problem of energy. If you really want to extend the Standard Model, at current energies, you have to look for very, tiny effects; and probably there are tiny effects buried in various processes. However, those tiny effects become large effects at higher energies, and that’s the way particle physics works. It’s like Newtonian mechanics and special relativity. You know, special relativity applies down to moving cars, but the effects are so tiny that it’s very hard to observe them, almost impossible. But again, at extremely high velocities, you can easily observe the effects of special relativity. So it’s the same thing with particle physics. There may be very tiny effects due to the physics at higher energies, but you have to get to higher energies to pursue them. Now the real problem is not the lack of interest or the lack of fundamental Physics to pursue, It’s the difficulty, both politically and financially, to get to higher energies at the present time. We’ve gotten to a point where it’s getting so expensive that, for example, CERN could only be built by a consortium, and that wasn’t easy.

Zierler:

Right.

Friedman:

So the problem is that unless you find some new way of accelerating particles that is much cheaper, getting to a factor of 10 to 100 times more energy is extremely expensive and difficult

Zierler:

It’s also a gamble.

Friedman:

Well, science is always a gamble.

Zierler:

Right.

Friedman:

No matter what you do it’s always a gamble. But, historically, it has turned out to be a good gamble.

Zierler:

But we’re talking about a $20 billion gamble where new physics might not actually be there.

Friedman:

That’s correct, and maybe we will need a machine that costs as much as $50 billion, and it clearly will have to be a multi-nation project. But society may not be prepared to do that. So it’s not the lack of interest or importance. It’s the lack of ability to carry out the necessary research because of its cost. It’s like saying, well, if you're designing airplanes and bridges and everything like that, Newtonian mechanics are sufficient, so we don't have to spend money trying to test relativity. But if you really want to understand nature deeply, it will take a lot more money than society may be willing to spend at the present time, unless there are some new discoveries about how to do it, or new inventions that allow us to do it at a cost that’s greatly reduced.

Zierler:

You think it’s worth the gamble personally.

Friedman:

Yes. If society can do it, it’s worth the cost. But of course, I realize that society has many, many problems. We are in the midst of a serious pandemic and it is likely that there are others to follow. The loss of life, and the economic devastation is causing enormous problems in society. Climate change is already having very destructive effects, and these will get worse in the future. These problems all require large expenditures by governments. Society has to make choices as to what it thinks is important to invest in. Large expenditures for big science projects may not always be possible. But, if countries across the world would divert some the money for the production of weapons into big science, we would all be better off.

Zierler:

Jerry, it’s so clear how incredibly gratified you feel to be part of fundamental discovery in science. I wonder if you can talk a little bit about — you know, almost from a Socratic method or perspective — what new questions came out as a result of some old questions that your research answered, that might still be open today.

Friedman:

Well, for example, one of the major questions is, Are quarks the ultimate building blocks of matter? Are there smaller constituents inside of quarks? Theorists have proposed such models. The upper limit of the size of quarks now is of the order of 10^-17 cm. So to explore this question would require enormous energies because the scale is so small. To see this, you would have to be able to break up quarks in particle collisions. Of course, they are looking for hints of this at CERN.

There are many other fascinating questions tin particle physics. How are quantum theory and general relativity, two of the pillars of modern physics, related? What would a more general theory that incorporates both of them look like? What would a theory that completes the Standard Model look like? There are also questions about the meaning and completeness of quantum mechanics. There are so many different questions that are really important that can be investigated.

Zierler:

So there’s no shortage of fundamental discovery looking ahead in the 21st century.

Friedman:

Oh no, there never is. There never will be. And then we have all kinds of issues in cosmology. What is dark energy? What is dark matter? How are they related to the subatomic world? Then you come to the question of cosmological models, and of course, they’re related to these other issues. Particle physics and cosmology are related in a very fundamental way. So there is no shortage of fundamental questions. We’re not even close to the end., if there ever is an end. Every period has thought that it’s scientific framework was complete. For example, Lord Kelvin, in I think 1891 or 2, said, “We’ve discovered all there is in physics. There’s only mopping up,” and we hadn't even discovered the structure of the atom or the nuclear force and related phenomena at that time.

Zierler:

[Chuckles] Right.

Friedman:

And we’re probably still in that phase, too. We know more, but it never ends, and that’s the wonderful thing about science.

Zierler:

Jerry, as an atheist, do you think that being a physicist gives you any sort of privileged position to understand how the universe works and to be convinced that there isn't any creator behind it?

Friedman:

No. Let’s put it this way. I know what I know and I know what I don't know. I don't know how it all started. Even if one talks about the Big Bang, the question arises, Big Bang where, how, and why? So I don't know, and I will die ignorant, but that doesn't bother me. I suspect the answers will never be known. So that’s just part of it. You keep on reaching and stretching, but there are certain things that I think will never be known in science. It’s just that the narratives of all the religions in society that I know of just don't make sense to me. That’s really what it is. It’s not that I know any more than they know. It’s just that their narratives don't make sense to me and they’re not compatible with things that I have studied; and so that’s the problem. But it certainly doesn't mean that I understand everything.

Zierler:

Right. Jerry, you’ve conveyed so beautifully and on such an important level all the interesting and important work that remains to be done in the field looking forward, and so I think for my final question I’d like to ask if you were a graduate student right now, you were starting all over, what do you think that you would do? Who would be — not to name a name right now, but the Fermi in your life, who you would latch onto to say, “This is a towering figure in the field, and this is some of the most exciting work to do”? If you were 25 today, right, what do you think it is that you would work on for the next five or ten years?

Friedman:

That’s a very interesting question. I’ve thought of that, and I haven't come to an answer yet because there are so many different interesting things going on and all of them are important, things in the physical sciences, and in the life sciences, things of that nature. I think it’s really all a question of what catches your interest at a particular stage in your life. I would have to go back and experience what’s going on around me when I was 17 years old and try to understand what would resonate with me at the age of 17 in this environment. The life sciences are so interesting today. The issue of what is life? How did it start? How do living systems work? Issues like that. Then, of course, as I said, there are enormously interesting questions still in physics, and I think it would either be something in the life sciences or still in physics. I think those would be my alternatives, but I’m not sure which one I would pursue. I would have to understand what would resonate with me at the age of 17.

Zierler:

But what you are sure about is that there is no shortage of things to choose from, and that’s the important thing.

Friedman:

Absolutely. How we end up doing the things we do in life is very strange. For example, had I not picked up this book on relativity in this particular museum, I may not have gone into physics. I don't know. Or maybe if I had picked up a different book, I would have gone into a different field. It’s what really catches you at a particular stage in your life, and what resonates with you and what you think you would enjoy doing for the rest of your life.

Zierler:

Well, Jerry, on that note, I just want to say it’s been an absolute pleasure speaking with you today. I’m so deeply appreciative that we were able to spend this time together and to hear your insights and recollections over the decades. This is going to be a tremendously important and engaging part of our collection in the Niels Bohr Library, and I really want to thank you for doing this with me today.

Friedman:

Well, you're very welcome;, and I want to thank you for your wonderful questions, David. Your questions were very insightful, They really captured the essence of things.

Zierler:

Oh, I appreciate that!