Philip Pincus

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ORAL HISTORIES
Phillip Pincus
Interviewed by
David Zierler
Interview date
Location
Video conference
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Interview of Philip Pincus by David Zierler on August 24, 2020,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
www.aip.org/history-programs/niels-bohr-library/oral-histories/46742

For multiple citations, "AIP" is the preferred abbreviation for the location.

Philip Pincus is a Distinguished Professor of Materials, Physics, and Biomolecular Science at UC Santa Barbara. In this interview, he explains the origin of his nickname “Fyl,” he recounts his childhood in San Francisco, as well as his decision to study physics at Berkeley and his mentorship by Charlie Kittel. Pincus describes his thesis research on temperature dependence of anisotropy energy, and nuclear spin relaxation in magnetic materials. He describes his postdoctoral work at Saclay and his faculty appointment at UCLA, and he describes working with de Gennes and Alan Heeger. Pincus describes his contributions to dirty type II superconductors and the excitement surrounding early research on liquid crystals. He explains his decision to join the research lab at Exxon Mobil and he describes the basic science research culture there and his increasing focus on soft matter physics, which he continued to pursue at UC Santa Barbara in the Chemical Engineering Department. Pincus discusses his current interests in water and cohesive energy, and at the end of the interview, he reflects on the growth of soft matter physics out of his original interest in solid state physics, and he explains why condensed matter theorists might have something to offer dark matter research.

Transcript

Zierler:

OK. This is David Zierler, oral historian for the American Institute of Physics. It is August 24th, 2020. It’s my great pleasure to be here with Professor Philip Pincus. Fyl, thank you so much for being with me today.

Pincus:

It’s a pleasure.

Zierler:

All right, so to start, the first mystery is the unique spelling of your nickname. Why do you go with F-Y-L?

Pincus:

OK, that’s a kind of a non-PC story. Want to hear it?

Zierler:

Absolutely, absolutely.

Pincus:

Over my career, I spent several years living in Paris. Once when I was there—this is before internet and computers, at least 20 years ago—I was in the de Gennes Group at the Collège de France. I have a good friend, Momo Daoud, a physicist, working at Saclay, the French Atomic Energy Commission lab. He had written a paper which was being typed, by de Gennes’ secretary at that time, Marie-France. She didn’t actually know him personally, but Marie-France was tasked with typing the paper for some reason.

As background, as I mentioned Momo and I were good buddies. And our daily greetings with each other was always something like “Fuck you” or its equivalent in in French or Arabic. On that day, I walked into Marie-France’s office when she was on her lunch break, and I happened to look at her typewriter, and saw a paper there that she’s typing for Momo. So I said to myself, “Oh, I’ll do a nice little joke .” So, on the first page of the paper, she had—as author Mohammed Daoud.I took a pencil, and I crossed out “Mohammed” and replaced it by “FY”. I figured, that Momo would see it in the drafts, and he’d immediately surmise what happened. But somehow it got published that way and when he saw it, of course he realized what happened. So he said, “Oh, must be Fyl, F-Y-L.” That’s it. So since that, I’ve been F-Y-L.

Zierler:

That’s great. It stuck.

Pincus:

[laugh]

Zierler:

All right, Fyl, well let’s start first with—please tell me your title and your institutional affiliation.

Pincus:

So I’m a professor jointly in Physics and Materials at UCSB, University of California, Santa Barbara. I’m two-thirds in Physics, and one-third in Materials.

Zierler:

Now let’s take it all the way back to the beginning. Tell me a little bit about your parents. Where did they meet?

Pincus:

New York. Both my parents are first-generation born in the US. All my grandparents came from, as they told me, was Ukraine. The name of the town was Kamenetz Litovsk, which is now in Belarus.

Zierler:

And then both their families both emigrated to New York?

Pincus:

Yeah …. my father lived for a while with his parents in Boston, but mainly New York.

Zierler:

And where did you grow up? What neighborhood did you grow up in?

Pincus:

Well, I grew up until the third grade in New York in the Bronx. But then during the Second World War, my parents moved to San Francisco. So I really grew up in San Fran—I’m really a Californian. I grew up in San Francisco from the third grade on.

Zierler:

Now, in your generation, there are a lot of really prominent people who came out of Bronx during that time. Do you have any contemporaries that you remember from those days that pursued a career in physics?

Pincus:

No, I left in the third grade.

Zierler:

[laugh] What were the circumstances leading to your family going out to California?

Pincus:

Well, my father had kind of a checkered history he’s a jack-of-all-trades. He never graduated from high school because he grew up during the Depression, and he had to work. And at the time when we moved, he had a small store that would’ve made us very wealthy because it was very close to what’s now Lincoln Center in New York in Manhattan… It sold eggs, butter, and cheese and things like that. But during the war, there was rationing and —it was very difficult for small businesses. And my grandparents…my mother’s parents, had long before moved to San Francisco, and they kept telling my parents, “Oh, it’s much better in California than New York.”

And finally, my father said, “Look, it’s just too hard to run this shop with all the rationing and stuff. I’m just going to close it, and we’ll just move to California… to San Francisco.” My father had many different jobs. He was very good with his hands as well as a sort of intellectual, and he worked with sheet metal companies in SF. At the end of his working career, he was employed by the post office in an administrative job, when he got very ill with rheumatoid arthritis, and had to retire early. And then only graduated high school after I was already a professor at UCLA .

Zierler:

Did you go to public schools in San Francisco?

Pincus:

Yes, only public schools.

Zierler:

And, Fyl, when did you start to get interested in science? Was that early on?

Pincus:

No, when I was in high school and getting ready to go to college, I was sort of a good student. I wouldn’t say nerdy but, was the local chubby kid who was a good student, and not very good at sports and things like that. I had no idea what to study. I had this conversation with my father about what I should do. I think my own goal was to go to college, and I thought I could become a pharmacist because I could probably do that. I wasn’t interested in biology.

I couldn’t do anything with my hands. I was completely incompetent in doing such things. And so I said to myself that I could count pills, “I could become a pharmacist.” When I spoke to my father about what to study study, he said, “Well, you know, you’re pretty smart. Maybe you should do something more challenging and interesting.”

My response was, “Well, I don’t know what can I do?” He responded that these were the days of Sputnik and physics - “You can become a physicist.” So I said, “OK ,why not, I’ll study physics.” So I had no idea about my level of interest.

Zierler:

So your father said to you, “You should become a physicist”?

Pincus:

Yeah, “Why don’t you do physics?”. Because that was the current “in subject” and was hard. “So, OK, I’ll try.”

Zierler:

Did you know you wanted to go to Berkeley? Did you think about schools farther away from home?

Pincus:

Yeah, well, I only thought about two: Berkeley because it was cheap, you know, my family didn’t have a lot of money. At that time, my father had a good buddy who was a Yale grad, who was lobbying me to go to Yale. So I applied at Yale and got a scholarship because we were rather— modest as far as our income was concerned. But I was not very mature. I wasn’t ready to go away from home. I was scared.

I didn’t know much; I was pretty isolated. I was an only child. I didn’t have a lot of friends, so I was afraid of going far from home. So I decided to go to Berkeley which was close. And relatively inexpensive. I remember I had to write out my tuition check for my first semester for $17.50.

Zierler:

[laugh] Fyl, did you have any idea—I mean, you know, being 17, 18 years old, you’re so naïve with things. When did you have an idea that the faculty at Berkeley was just unbelievable, and that there was so much exciting stuff that was going on at that point? Did that sort of dawn at you right away, or that took some time to sink in?

Pincus:

I guess it took some time to sink in, and I didn’t realize that. I knew Berkeley was a good school. But I didn’t know that it was that great.

Zierler:

How did you go about sort of identifying the areas in physics that you were good at and that you wanted to pursue?

Pincus:

Well, OK, when I started out as a freshman, I didn’t know I could even succeed. In fact, we all have that uncertainty on how we could manage. And I was scared to death. I remember my first mid-term exam in freshman calculus. I got an F. I thought I knew the stuff, and yet I failed. And I said to myself, “oh shit…..” So I started out very poorly.

But then as time went on, I was doing well. I realized that because— was incompetent with my hands that I had to do theory.so I never seriously considered doing experiment just because I was a “klutz” even though my father was good with his hands. He could do everything, and I could nothing. I couldn’t hammer a nail into the wall without bashing my finger.

Zierler:

[laugh]

Pincus:

So, I would say as soon as I realized what physics was about, I knew that I ought to do theory, that I had no choice. And then by the time I graduated from Berkeley, I realized that Berkeley was a great place, and so I wanted to stay if I could for graduate school. And that was a time when everybody said you shouldn’t stay at the same place….it was best to go away for graduate school. At that time, we all had undergraduate advisors, and mine was Art Kip who was a very well-known experimentalist in solid-state physics doing cyclotron resonance in metals.

When I was a graduating senior—and thinking about applying to grad schools he said, “Well, I would have to write you a letter, but I think that you should stay here. , So, I won’t write you a letter anywhere else, only here. So you have to stay.” And so that was that—he played a significant role in my development…. Otherwise I would’ve gone somewhere else. And nowhere else except Illinois was doing solid-state physics at that time.

Zierler:

And of course, the term “solid state” also included what would later become soft-matter physics. In other words, later on we have condensed matter, and there’s soft matter. But would solid state in those years have included soft-matter physics, or was simply no one doing soft-matter physics?

Pincus:

I don’t think they were doing it. In fact, nobody that I knew was doing it. I’d never heard of it.

Zierler:

So during your time at Berkeley, what did the term “solid-state physics” encompass? What did that mean?

Pincus:

Oh, metals, magnetism, semiconductors, superconductivity. And it could leak out maybe a little bit into quantum fluids like helium. Nothing to do with macromolecules—I’d never heard of the word “polymer”.

Zierler:

Fyl, did you have a sense—I’ve heard from other people, contemporaries—like I remember Bert Halperin told me that Wolfgang Pauli referred to solid-state physics as “schmutz physics”, right, which indicates that there is a hierarchy in physics, right? Did you have a sense—?

Pincus:

Of course, when I was doing solid-state physics, Gell-Mann called it “squalid-state physics.”

Zierler:

Right. [laugh] So at Berkeley, did you get the sense that there was that hierarchy? Was—you know—was theory on top, and solid state was near the bottom?

Pincus:

Solid state was near the bottom. It was viewed by many physicists as engineering. And in fact when at that time there was an intense struggle going on wether solid-state physics should by be in Physics Departments or in engineering?

At that time, the only big schools where solid state was in Physics were Berkeley and Illinois. Maybe a little bit at Penn, and maybe just barely beginning at Harvard. And at other places like Yale, it was definitely in engineering. And that’s why Yale was much late coming into that game.

Zierler:

Who did you end up working with for your graduate studies?

Pincus:

So I worked with Charlie Kittel.

Zierler:

You did. And what was Charlie working on during those years?

Pincus:

Magnetism, although at the end of my time, he was starting to get interested a little bit in biology, which caused his early retirement.

Zierler:

[laugh] In what ways?

Pincus:

CK [Kittel] was not an easygoing person, and he got very angry with what people were saying about his work in biology. So basically he said “Oh, screw that. I’ll just retire.” But mainly, his students we were working on magnetism.

Zierler:

And what were some of the major research questions in magnetism at that point? What were the most important questions to consider?

Pincus:

Well, the thing that we were most—that I was mostly involved in were— experiments going on at Bell Labs on magnetic resonance in magnetic garnets, ….for electronic devices. And so I was heavily involved in ferromagnetic resonance and relaxation —- mostly spin wave theory.

Zierler:

Now, in terms of developing your dissertation topic, did Charlie essentially give you a problem that he was working on, or did you develop something more on your own?

Pincus:

No, he more or less told us what to work on. But they weren’t things that he was working on necessarily. They were things he was maybe thinking about in the background, but he never worked with us. Once he asked me to do something, he was hands-off. He didn’t do it in parallel.

It was your thing, and you could talk to him whenever you wanted. But he didn’t work with you. You were on your own. Sometimes he would ask you to work with a postdoc. He had outstanding postdocs and visitors while I was there. So we had a lot with those people with whom to interact.

Zierler:

And what was the central research question of your dissertation? What were you working on?

Pincus:

There wasn’t one. We—I worked on several—lots of different problems I started out with magnetic resonance in thin films, quantized spin waves because of the boundary conditions. My first problem was actually on the temperature dependence of anisotropy energy of antiferromagnets. By the end of my graduate school days, I was doing a lot of work on nuclear spin relaxation in magnetic materials. So, there wasn’t one problem. If you look at my thesis, it’s about four or five papers stuck together that are all on magnetism, but not necessarily related to one another.

Zierler:

Do you remember who was on your committee?

Pincus:

Outside of him, yeah, well, Al Portis, who was a terrific NMR experimentalist, with whom we collaborated. Possibly Mike Tinkham, but I’m not 100% sure. He was at Berkeley then. And we also worked a little bit with him because his group was using infrared to do resonance in antiferromagnets. And there was an Engineering professor , and I think his name was English. During my thesis defense, he asked me a question which I answered ( I don’t recall the question nor my answer), but Kittel didn’t like my answer. He answered it independently which provoked a rather unpleasant interaction between English and CK.

Indeed there are lots of Kittel stories. I could go on and on. He was a difficult thesis advisor; with CK, you learned how to write because when you wrote papers, you had to write them, and usually rewrite then, maybe ten times before he allowed them to be submitted. CK would nor rewrite them...he would scribble comments in the margins, and you would rewrite and rewrite….He was a stickler for using proper English. So we learned how to write in a very painful way. But we learned how CK liked papers to be written.

Zierler:

So he might’ve been difficult to work with but, in the long run, it was probably a benefit for having gone through that?

Pincus:

I think so. And then he—for me, it was important because, like many young people, I was pretty good at mathematics, but I didn’t have a very well-developed physical sense. And with Kittel, you had to understand things physically. For example, when we would have a meeting with him to discuss and tell him what we’ve been doing, there were certain rules. And one rule is that you couldn’t describe anything with mathematics.

You had to describe it with physics. And he expected that you would do the mathematics correctly. But if you had to use mathematics to explain something, that meant that you didn’t understand it.

Zierler:

Fyl, when you finished your defense, what did you want to do next? What were the opportunities that were available to you?

Pincus:

OK. Well, so by then I knew I wanted to do academia. And the fallback position if we didn’t do that, we knew that we could always get jobs in industry. The worst-case scenario was to go to work for Hughes Aircraft or Boeing. And there were Bell Labs, General Electric, and IBM. So, but things were organized for us to go into academia.

And so at that time, CK’s students, just before you finishing their PhD,’s would take an interview tour on the East Coast, because most of the jobs were on the East Coast. I took such a tour.

I went to Bell Labs, to General Electric in Schenectady, to IBM, a couple of different IBM labs. I also visited Penn because I had buddies who were a little ahead of me who had gone to Penn. Penn was an outstanding place for us with folks like Herb Callen. But by then I had already received an NSF postdoc and knew I was going to Europe for a postdoc.

I recall when I was at Bell Labs after my interview, —I think my host was Phil Platzman — told me, “Well, we know that you really probably want to go to academia. But if you want to come to Bell Labs when you’re ready to come back from your postdoc, just write us a letter.”

Zierler:

And so what did you end up doing?

Pincus:

Well, I ended up going—to a postdoc to Saclay in 1962. And that was a good thing for me because I had to wound up learning some French, which I knew nothing about. And then my first real job was at UCLA. I had offers—basically, from Penn and UCLA; I almost went to Penn. That’s another interesting story. In fact, I thought I would go to Penn.

But my wife at that time—my first wife was from LA; she was lobbying for LA. And because of her contacts, I ended up going to UCLA with Ray Orbach, who was also a Kittel student but about a year ahead of me. In fact, my first paper, was co-authored with Ray. When I was doing my post-doc, Ray was an Assistant Professor at Harvard. He had heard that I might go to UCLA, and he wrote me a letter that he’ll probably come to UCLA as well . And so we had kind of agreed to go to UCLA together. When I was at Paris, I was at that time already working a lot with Pierre-Gilles de Gennes. “He was doing his military service year first, on an aircraft carrier off of Normandy.”” He’d often come home weekends, when I would see him. He was actually in North Africa at the French atomic bomb tests. But as far as I knew, he was on a ship off of Normandy.

Zierler:

I’ve heard so much about de Gennes. What made his research so significant, in your view?

Pincus:

Well, first, he also was a postdoc with Kittel when I was a graduate student….so we learned about physical intuitions from the sam preacher. So PG’s physical intuition was impeccable. He was extremely creative. Also he had a wonderful education. He came up through the École Normale. His professors were the first generation of post WWII French physicists…he learned from these great people.

And he was just fearless—he was not afraid of anything, and he was especially not afraid of making mistakes. When he attacked a problem, he didn’t have to start from some theorem. His approach would often be to speculate… Let’s guess that it’s like this and see what happens. Also he was technically good, but didn’t like to show it. PG learned from Kittel that, when you do something in theory, you should obtain the same answer more than one way. But PG would only show the easy way.

Zierler:

So what was one of the things that was attractive to you about Penn? Was exciting stuff in solid state going on at the time there?

Pincus:

Yeah, lots of good people in magnetism. Schrieffer was there. And Herb Callen. And there were buddies of mine who had gone there. Like—Alan Heeger.

And so it was a natural place for me and, it wasn’t as snobby as the other Ivy League schools. And so I thought it would be a good place. They made me an offer, and only at the last minute didn’t I go. In fact, it’s an interesting story. Before leaving to Paris on my post-doc, I also took an interview trip to UCLA.

UCLA had basically no solid-state physics then, but they wanted to get into it. In that era it had a pretty mediocre Physics Department. There were a few good people, but not up to the UCLA level. The had very good group doing acoustics led by Izzy Rudnick.They also had a wonderful theoretical nuclear physicist, Dave Saxon, who later became President of the University of California. One of Dave Saxon’s seven daughters was an acquaintance of my ex-wife. .So when I interviewed at UCLA we had dinner, one night, with the Saxon family.

The year that I was a post-doc in Paris at Saclay, by pure accident, Saxon was on sabbatical also in France at the École Normale. And in mid- year, I had offers from both UCLA and Penn, In fact, I had written a letter accepting Penn. But, I didn’t send it because I wrote the letter on a weekend, and I didn’t have any stamps. At that time, you had to do everything by mail.

Zierler:

[laugh]

Pincus:

The post offices in Paris were closed on Saturday, so I didn’t send the letter. It was all written, just ready to go on Monday. But that weekend on Sunday, we had agreed to have a picnic, totally independent of anything, in Fontainebleau with the Saxon family.

And during that picnic in Fontainebleau on Sunday, he convinced me to go to UCLA. And I never sent the letter to Penn.

Zierler:

But UCLA obviously worked out for you?

Pincus:

Yeah I went, and then Ray Orbach came a few months later. And then the thing that was amazing, there was a guy who had been a yearly summer visitor to UCLA by the name of Ted Holstein, who was a professor at Pitt and had been at Westinghouse. This guy was one of the great solid-state theorists of that generation, but he wasn’t known to us because he worked on different things. He wasn’t a magnetism guy like we were, although he had co-authored the famous Holstein-Primakoff transformation of spin wave theory when he had been a post—doc . He worked on transport theory but was not famous like Phil Anderson with that generation. He was a theorist’s theorist. Extraordinarily smart and very creative. If. you look him up, you’ll see he’s one of the great men solid state physics. But he wasn’t famous because he had this reputation for being rather unpleasant to other physicists.

But he and Izzy Rudnick, were buddies, Ted and his family was spending summers in UCLA because they were then living in Pittsburgh. I first met him when I was—an assistant professor, and then I quickly realized this guy was “something else,” an unbelievable scientist. By then, he was getting older, and starting to become a little mellow. He was like a mentor to me, and he helped me, no end. He taught me about field theory and many-body physics because we weren’t allowed to learn those when I worked with Kittel because they were too much of a time sink.

Zierler:

Fyl, I’m curious, coming from—you know, previously being at Berkeley, did you sense that there was any rivalry between UCLA and Berkeley? Did you see UCLA in those years as striving to be a competitive counter in physics to Berkeley?

Pincus:

Well, it was striving, yes. It was so far below Berkeley in physics that there was no real competition. Also, in Physics at UCLA, when I was there, there was a lot of internal divisiveness between two groups where people didn’t talk to each other, so we had few Department meetings.

Zierler:

Wait, you’re talking about at Berkeley, there were these problems?

Pincus:

No, it was UCLA. Berkeley was a different problem….it was a set of strongly interacting prima donnas. But at UCLA, there were these two factions; we were a little bit orthogonal to them but bit closer to the acoustic group than the nuclear physics people. UCLA was getting better, but it was a struggle to hire good young people.

Ray Orbach and I were working very hard to grow solid-state physics; we got Hans Bömmel to come from Bell Labs. Hans was an outstanding ultrasonics guy. Then Ray and I were able to convince Gill Clark to come from George Feher’s group at La Jolla. But it was a very tough go at UCLA in solid-state physics because we were not on the map.

Zierler:

How did you research change when you came to UCLA? Were you looking to take on new projects? Were you looking to continue what you were doing previously?

Pincus:

Well, a little bit of both. I was more of a follower than a leader, . So I was still— doing magnetism; my first student, Dave Beeman, did an extension of my thesis from Berkeley on NMR in magnetic materials. But at the same time, I was learning stuff from my buddy, de Gennes. And so at UCLA, I started with magnetism, but then I transferred a bit to superconductivity because I had learned that from de Gennes.

I was going back and forth to France fairly often. Of my 20 years at UCLA, I spent about five living in Paris. I was taking sabbaticals and leaves of absence., working with de Gennes and his group. I was learning from them, superconductivity and liquid crystals At the same time, I had contact with my buddy, Alan Heeger, who was at Penn. He and I had been very close at Berkeley, where he was doing experiments with Al Portis, and we wrote papers together as graduate students. He was getting me interested in organic conductors, so that’s when I started learning about Hubbard models in the ’70s.

So we were doing new things. I always liked to learn new things, so I always wanted to be in the steep part of the learning curve. But that means that I was never becoming one of the known people in a given field because I was always changing subfields.

Then also I was learning from de Gennes. I was learning from Ted Holstein. I was strongly interacting with Alan Heeger. And then Ray Orbach was there who was pushing us to work on spin glasses. I was doing all these things at once.

Zierler:

And what was Heeger working on at that point?

Pincus:

Well, he was working on organic conductors, such as TTF-TCNQ molecules which have electron transfer. They are organic molecules but not polymeric. And they’re strongly correlated, as we quickly realized; I, therefore, was learning about Hubbard models. John Hubbard had been a postdoc in Kittel’s group while I was a grad student. I believe that—he wrote his famous Hubbard model work at Berkeley.

But at that time, I didn’t understand any of that. Only at UCLA did I start learning about Hubbard models; I spent several years with my students maybe in the late ’70s until maybe till about ’80 on Hubbard models coupled with polarons because I’d learned about polarons from Holstein. But at usual for me, when I was doing it, it wasn’t very fashionable.

Zierler:

Why do you think that was? Why was it not fashionable yet?

Pincus:

Well, because solid-state physics until around that period was an open area where in any sub- field, there was stuff to do. Nowadays, it seems there are only a finite number of problems In those days, it wasn’t that way. You could work on anything in solid-state physics, and you would find something new to do. So there was just too many things going on at once. And there were people working on Hubbard models, but not many. More people were working on BCS superconductivity, and we did too, as well.

Zierler:

And what were some of the major questions in superconductivity that were being asked at this point?

Pincus:

Well, at that time, you know, we were interested in dirty type II superconductors; no high-Tc yet. Yet there were folks—like Bill Little at Stanford—thinking about how you get high-Tc could be achieved because that was the name of the game if you wanted to make superconductivity useful for the general public. So there was a lot of work going on on mechanisms.

We weren’t working so much on mechanisms, my interest in type-II superconductivity was on how to understand vortices, interactions between vortices, and I was always interested in nuclear magnetic resonance….what NMR sees in terms of studying the elementary excitations in superconductors and magnetic materials and even liquid crystals? I worked for a while in liquid crystals, with one good paper, again that was probably with de Gennes on nuclear T_1‘s in nematic liquid crystals.

And it was a result of a typical thing with de Gennes,….. we would have bets on everything, for example, how many bridges between here and there, and things like that. And I almost always lost. Well, one bet that we had was if NMR, T_1, could tell you anything about liquid crystal fluctuations. And he said, “No.” But I did not have any reason to say anything —so we bet a dinner. And then of course we had to do the calculation.

We spent one day doing the calculation. And by luck, it was the only physics bet that I ever won against PG . I was right because I was lucky and it was a very subtle effect. But, it was that kind of thing that we were doing. I wasn’t working in any one area. We were just bouncing back from one area to another. Liquid crystals was the first foray into what you might call soft matter.

Zierler:

Right, right. And liquid crystals at this point, this must’ve been a very exciting new field.

Pincus:

Yeah, again, it was typical de Gennes. He would like to find field where there wasn’t much understanding. he said, “What we’ve got to understand can’t be so complicated.” And often he started with what he knew from his thesis on magnetism, and how to think about fluctuations. He thought a lot about fluctuations and correlation effects to develop a theory for liquid crystals. I was just hanging around and learning.

In fact, that’s how I learned superconductivity. When de Gennes was at Berkeley, he decided that he should learn about superconductivity, so he was studying the BCS papers as well as the papers from the Soviet group. Then when he went to Paris to become an assistant professor at Orsay, he gave a course on superconductivity. Just about that time, I took a leave of absence from UCLA to spend a year at Orsay. And when I arrived, the de Gennes Group was working on superconductivity about which I was ignorant. When I arrived, PG said, “What do you want to do?” I said, “What about superconductivity? What should do?”. He says, “Well, I gave this course, and students took notes, which they mimeographed. And I’m thinking maybe I should write a book. So why don’t you look at these notes. You learned French and it’s pretty good now. Why don’t you translate the notes, and we’ll do a book?”

So I started translating them into English and thereby learning the subject. But at the same time, the field was rapidly evolving. So when I passed over to PG what I had translated, he often said something like “Let’s do it a little different way.” But for the book, he wrote that in English. Finally all of this became the de Gennes book on superconductivity. I was listed as a translator, but there was no French version from which it was translated.

Zierler:

[laugh]

Pincus:

It was translated from the lecture notes that his students had taken.

Zierler:

[laugh] That’s great.

Pincus:

That’s how I learned superconductivity.

Zierler:

Fyl, can you talk a little bit…I’m curious, first of all, your lab at UCLA, was it one lab, and you did all of your work in here, or all of the experiments that you worked on took place in different labs?

Pincus:

I don’t do experiments. I’m a theorist, so I didn’t do experiments.

Zierler:

But I mean, in terms of your interacting with experimentalists and things like that, would you go around to the—?

Pincus:

No, I worked with other people. So—at that time—there was Gill Clark at UCLA and I worked a lot with Heeger when he was at Penn, and I worked with Vince Jaccarino at Bell Labs. Vince later moved to Santa Barbara. In fact, that’s part of how I ended up at Santa Barbara. We tried to hire Vince at UCLA, but he liked Santa Barbara much better.

So then I was interacting with several different experimental groups. I seemed to have a knack with working with experimentalists. I wasn’t too good at doing theory. I had never studied field theory and I didn’t know anything about computers. But I was pretty good at working with experimentalists, trying to use simple de Gennes, Kittel ways of thinking to figure out what they were finding.

Zierler:

And can you talk a little bit about what were some of those advantages or, I’m sorry, advances in technology that the experimentalists were using that was helpful to you in terms of advancing the theory?

Pincus:

OK. So, first, there was a lot of advances in engineering and electronics, especially going to higher frequencies. When I was a graduate student, the best you could do were microwaves. Now, they were going into higher and higher frequencies. Also, the laser was discovered when I was a graduate student, and so all these laser-based technologies were starting to come online, such as light scattering. And, again, through de Gennes, I learned about neutron scattering. His thesis was about neutron scattering in magnetic materials and he was always maintained an interest in neutrons. So, I was learning about neutron scattering.

Also from my postdoc in Paris, where I was in the. Abragam group at Saclay, I was learning about magnetic resonance, T1,T2,T2*,, how to understand line widths and relaxation. At Berkeley we had good courses on quantum mechanics, so I knew about perturbation theory, and how to use higher order perturbation theory to get relaxation times rather than just using phenomenological models for scattering. So I was in to that kind of science and I had good experimental buddies that I would talk to, like Alan Heeger and Jacques Winter (Saclay). Of course these guys were not run-of-the-mill experimentalists. They were great. At the time, I didn’t realize how good that they really were…..they we’re just “my buddies”..

And it was similar with the experimentalists around de Gennes in Paris.

Zierler:

Fyl, to flip that question around, in what ways were the advances that you were making in theory useful for the experimentalists?

Pincus:

I think we were useful. The experimentalists would come to us and say, “Look, we have these observations. We think it’s sort of like this but how do we calculate anything?” I had a very, very close relationship with Vince Jaccarino, who had moved from Bell Labs to Santa Barbara, on magnetic resonance in ferro- and anti- ferromagnets. People who were working on vortices in supercomputers would call and say, “Well, we’re doing this work. We’re trying to understand the magnetic flux things. How do we understand these observations that we’re making?”

Some people called—I don’t know why they would come to me. Possibly they would approach PG and he might say, “Talk to Fyl” or something like that.

Also we (PG and I) had this great buddy who I should have mentioned earlier, Shlomo Alexander, who died too early in an automobile accident. He was spending time with Ray Orbach at UCLA, mostly on a spin glasses but was also working with de Gennes on a variety of problems. One day (in 1978) at UCLA, Shlomo and I noticed an interesting experimental paper by Paul Richards on diffusion in a quasi-one dimensional system. This was diffusion of particles that were constrained to bang into one another. We spent one afternoon thinking about it and we wrote a paper on what’s now called single-file diffusion. That’s all that we did on that problem.

And then, maybe five or six years ago, I was spending time in Korea. There was the International Conferences on Statistical Mechanics taking place in Seoul that year. So because I happened to be there, I attended. One afternoon at a coffee break, a gentleman, who I didn’t know, walked up to me and asked, “Are you the Fyl Pincus that wrote a paper on single-file diffusion with Alexander?” “Yeah, yeah, a long time ago.” And he said, “Oh……don’t you know that this has become a big subject and that there are sessions devoted to various aspects at conferences like this?” The subject has become too sophisticated for me to follow now. Shlomo and I just happened to be at the right place, at the right time.

Zierler:

Fyl, I hear similarities both in terms of how there wasn’t a central question that you pursued in your dissertation, and there wasn’t a single project that you worked on over your years, you know, on the faculty doing this research. And so that just begs the question, of all of the interesting things to work on because you had such a diverse research agenda, how did you go about choosing what projects to work on, and which ones not to?

Pincus:

Well, the thing I choose to work on? As I mentioned earlier, I always liked to be on a steep learning curve. So I don’t want to work on something where I know what to do. I want to be able to learn something that I don’t know. So that reminds me of a time when I first concretely realized something. We were working on correlated electrons for Heeger’s organic conductors with my grad students at UCLA when I was chairman of the Physics Department. That was a pretty active field in the early 70’s. I was working with Gerardo Beni, who was then a grad student. I told him, I said, “Look, we got to do this quickly because if we don’t do it, there’s this other guy who was in Boston, a competitor, who’s going to do it.” And then I stopped, and I said, “Oh, if he’s going to do it, it will get done. Why should we do it? Let him do it. Let’s do something else.”

Why should we be racing to compete with somebody! That’s just not necessary. But the result is that I’m usually working on things that are not fashionable. They may become fashionable afterwards, but not while I’m working on them. I’m always working on something that nobody cares about.

Zierler:

Fyl, I’m curious, you know, we already talked about where you saw UCLA’s stature in the early years. You know, over the decades that you were there, how did that stature rise or fall, from your perspective? Where was UCLA by the time you left?

Pincus:

When I left, it was much better than when we arrived. I’m talking about Physics. UCLA, at that point, was already strong in other disciplines. For example, Chemistry was outstanding. I had a great friend there, John McTague, who did very good work on adsorbed monolayers. He had a super post-doc, Dan Frankel, who just retired from a chair in Cambridge. And then there’s Bill Gelbart, who’s still there in chemistry. He was then working on nematic liquid crystals and has now become a terrific virologist.

So the science strength of UCLA then was in Chemistry. And we were trying to build up Physics. I thought that we weren’t bad yet not very respected. There was Ray Orbach who was outstanding, and Shlomo Alexander would visit all the time; he was great. But we were never viewed as a strong group. The stature was going up, but I just didn’t appreciate it as much as it was.

Zierler:

Who were some of your standout graduate students at UCLA?

Pincus:

The strongest one that I had, and he was great, was the fellow I mentioned before, Gerardo Beni. He went on to do a postdoc at Bell Labs, and got into robotics, and actually came to Santa Barbara, and is now retired from UC Riverside doing robotics. He didn’t do physics as I would’ve thought he would. But he was outstanding.

My first student was Dave Beeman who worked on NMR in antiferromagnets. He went on to have a good career at Harvey Mudd. So at UCLA, I don’t think I ever had any student that made big splashes in physics. Most of them became good engineers and ended up in science administration.

Zierler:

So when 1983 came around, were you looking for a change? Were you putting out feelers for new opportunities? Did Exxon come and recruit you? How did that all play out?

Pincus:

OK, so that was a very different story, yeah. So, at that time already, things were good at UCLA. We had hired Paul Chaikin whom I knew from superconductivity. He had done his thesis with Tony Jensen at Penn and then was a post-doc with Alan Heeger. I realized quickly that Chaikin was an unbelievable guy. At that time, I wasn’t getting restless, but I was going through a divorce.

And that was at the same time that Exxon was building up its lab. And one of the guys that I knew there was Bernie Silbernagel who had been a postdoc and a young assistant professor at UC Santa Barbara with Vince Jaccarino. Bernie and I collaborated on nuclear spin-lattice relaxation in antiferromagnets. Bernie couldn’t get tenure at. UCSB because his research was too close to that of Jaccarino. On leaving UCSB, he was recruited to Exxon. And out of the blue when I was at UCLA, he called me and said, “You know that Exxon is trying to build up in in soft matter,” and would I be interested? And of course I wasn’t really interested. But after several calls, I decided to find out and wound up visiting the Exxon lab in Linden, N.J.

At that time, the CEO of Exxon Research and Engineering was Pete Lucchesi who was a great salesman, trying to convince me to join. And at the same time, I was going through a divorce and moving toward soft matter. Also Chaikin was switching to soft matter. We said, “Well, we can’t do anything. It’s just the two of us at UCLA.” Bill Gelbart was already at UCLA, but he wasn’t yet doing soft matter. And so we said, “Well, how can we get a critical mass group at UCLA?”

Zierler:

But now, Fyl, I want to ask, so what it’s just the two of you? Why do you need more than that?

Pincus:

Chaikin and I were struggling on how we could bring some more activity in soft matter. We went to the current dean of sciences at UCLA, an experimental high energy physicist by the name of Harold Ticho, a high-energy physicist. Paul and I went to meet with him where we explained what we wanted to do, asked if he could help. Harold’s response was “I don’t know what I can do. I’ll get back to you.”

So about a week later, he calls us up, and he says, “I’ll tell you what. I’ll do the following.” This was a time when there were a lot of jobs. He said, “If Chemistry and Physics will each give 1 FTE to Soft Matter, I’ll match it so we would have four new positions.” So Paul and I went to the chairs of both departments. Of course, they both came back to us with what what I would’ve told us too that, “Look, we hire the best people we can. We don’t want to make a programmatic decision that narrows the field. We want to hire the best people.”

But for us that was a resounding “NO” because Soft Matter was a young field. The strongest Condensed Matter physicists were working on superconductivity. Even though people like Bill Gelbart and Ted Holstein were saying, “No, no, stay here, we’re going to manage. We’ll manage doing what you want.” But both of us decided to leave. Paul was also being recruited from Exxon but he didn’t go. He chose to return to Penn. And I went to Exxon.

Zierler:

When you took the work with Exxon, did you feel like you were leaving academia for private industry, or were you just looking to do basic science in a different environment?

Pincus:

Good question. Well, when we were attracted to Exxon, what was sold to us was that Exxon was going to become the Bell Labs of energy instead of electronics; at that time, Exxon viewed themselves as an energy company, not only oil; they had significant nuclear and coal resources. They wanted to become as academic as Bell Lab. So when they asked us to come, they told us “You guys could what you want to do, as long as it’s somehow related to our long-range goals.” So I thought I was going to something like the Bell Labs 11x groups.. Exxon would have healthy resources to invest. That was what attracted me. The opportunity to build up a strong research effort in Soft Matter. I had no thought of ever going back to academia.

Zierler:

Did you feel like you were going to be able to accomplish things at Exxon that you couldn’t do in a university environment?

Pincus:

Yeah, because we knew that we were going to be able to hire people, and we felt that the time was ripe. We thought that we could get Exxon to invest in an X-ray beam-line at Brookhaven as we as a share of a neutron line at NIST. We were thinking “big”. We were aware that we would have to convince our bosses; but we felt that our bosses had vision and would be supportive. Of course, the grass is always greener then where you are. And we learned some different realities when we got there, but that’s OK. And it was, on balance, a terrific environment. I was there for three years; scientifically, it was the best three years of my career.

Zierler:

Did you ever feel like you were working toward the bottom line for Exxon, or was it really a basic science environment?

Pincus:

No, what we were doing was science. I mean, of course, there were people around us working on Exxon problems. It was a strange environment then because there were people like me and Tom Witten, who came afterwards, and Sam Safran, and Paul Chaikin who also had a lab at EXXON. There were also Dave Weitz (now at Harvard) and Steve Garoff (now Carnegie-Melon) who were already there when I arrived.

We were viewed by the typical Exxon folks as occupying an ivory tower and doing stuff that was unrelated to the company and was just a waste of time. For example, I was in a carpool with typical petroleum engineers, who disliked us because we were like spoiled kids, getting whatever we wanted, without doing anything useful. So almost every day in the car pool, there would be bantering about this. But Exxon, in those days, as I mentioned earlier, had a CEO, Pete Lucchesi, who was a real oil field engineer but loved science, and was extremely supportive.

I’ll provide an example of the culture shock that with which we dealt at Exxon. I had a friend from Paris, Ludwik Leibler, who had just completed a 2nd PhD with de Gennes. Ludwik was a Polish émigré to France, who is now a great French polymer scientist. When he completed his doctorate, Ludwik asked me about spending a summer with us at Exxon. (I suspect that this idea was PG’s suggestion.). I said, “Sure, this would be great.” So I went to my immediate boss, who was a young typical Exxon oil field engineer, and I said, “We would like to invite Leibler to come just for the summer.” And he hemmed and hawed and blah, blah. “Well how much is it going to cost?” “Well, we have to cover his expenses”. I remember a number like $5,000 which was negligible on the Exxon scale. I never got an answer.

But finally after going back and forth several times, he said, “Look, I don’t know this guy. He’s going to come here and learn all our secrets and take them back to Europe. I don’t want to do it.” By the way, there were no secrets of which I was aware. I was stunned. This never dawned on me. I went for advice to Bob Lundberg—who had been at Exxon for a long time and was a great chemical engineer working on polymers. Years before, Bob had invented a refining process that made a lot of money for Exxon,, so was well respected at the lab. He had advised me not to come to Exxon for precisely this kind of event. I went to him, and told him the story. “What can I do?” And he laughed at me and he said, “So I told you so!” And he said, “I’ll tell you what to do. Here’s the name of a guy who was a middle manager at Exxon Chemical, which was another Exxon company on the same campus in Linden. He said, “Why don’t you call this guy, tell him the story, and ask him if he can help?”—a guy I didn’t know.

I did what Bob suggested. I called up the guy at Exxon Chemical, two buildings away, and he asked me what I wanted, and I told him the story. Of course, he had no idea who I was. He didn’t know me from anybody. And he said, “So you want to bring this guy in?” He said, “Well, how much is that going to cost? I said, “Well, about $5,000.” And all of a sudden there’s just silence. And he said, “I’ll call back tomorrow.” Now in between, I’m sure that he spoke with Lundberg. The next day I received a 5K$ internal transfer. I never heard from the Exxon Chemical fellow again but much later in his career, he became CEO of Exxon Chemical.

A related situation happened with Bill Graessley, who was a marvelous polymer chemical engineer, who came to Exxon about the same time that I did, also from academia. He left Exxon about when I did as a professor of Chemical Engineering at Princeton. Bill was also having similar issues with the mid-level ER&E administration. So one day, Bill and I went to see Pete Lucchesi, the CEO, and we said, “Pete, we just can’t operate this way. Our boss blocks us from doing anything. He doesn’t understand science”. Pete explained to us the Exxon culture of rotating administrators from the oil fields through other part of the corporation to broaden their vision. And he said that he would get back to us. We met again in a few days. He said, “Well, what should I do? What can I do?” Bill and I explained that we needed a manager who’s sympathetic to science. So he called us back a week later and said, “OK, I could do that. I can block this rotation system for this special case, but you two have to find a manager.

So I remember Bill and I went searching, looking all over the world in order to find somebody who wasn’t an Exxon employee to hire. We succeeded—and things got better and better. So we had cultural wars at Exxon, but it was great.

Zierler:

Did you see—were you still pretty well connected with academic physics during your years at Exxon? Were you still going to conferences, and writing papers, and all of that?

Pincus:

That’s right. We were getting our buddies like PG and Shlomo to visit. Exxon was hiring great people like Tom Witten, Sam Safran, Dave. Weitz was already there, Cyrus Safinya came from MIT…he’s also now also here at Santa Barbara, Gary Grest, Mike Cates, Mark Robbins, and I can go on and on. There were just unbelievable people.

During our years in New Jersey, Exxon built a state-of-the-art new laboratory in Annandale, near Clinton near the Delaware Water Gap. In the Annandale lab, there was a big atrium with a coffee cart. Many of us would show up there first thing in the morning and informally chat usually ending up with science. There was unbelievably good stuff, you know, people yelling and screaming at each other and even experiments. More than once experimentalists would prove that us theorists were wrong by setting up simple experiments right there on the coffee table, which was technically illegal by Exxon safety rules. That was an unbelievable few years.

Zierler:

And what do you see as you—?

Pincus:

We’re still--

Zierler:

Go ahead.

Pincus:

We were welcomed back into academia. Many of our old Exxon crowd are in academia. I remained still very well-connected to Heeger. For example, Heeger had come to Santa Barbara, and was lobbying for me to come there.

Zierler:

What do you see as your greatest contributions during your time at Exxon?

Pincus:

Scientifically?

Zierler:

Yeah.

Pincus:

I think my greatest contribution was not any one thing in science. I think my greatest contribution was helping develop the atmosphere where people could talk and not be afraid of others stealing ideas. We were trying to get together, work through some ideas, and figure out some science. I was also. worrying about recruiting and trying to get good people to come and visit. Those were my main contributions.

I did contribute to papers on various subjects. We did a lot important work then on charged polymers. But I think, again, most of my contribution was more on the social side rather than on the real science side. The people that we were hiring were much better than I was. I mean folks like Tom Witten and Sam Safran. These guys would come to me and say, “Look, I’m thinking of this, and I’m thinking about that. What do you think? You know, how do you think about—?” And, “Well, maybe we should talk.” I would say something like, “Maybe we should talk to Shlomo Alexander. Let’s go call him up.” In other words, I was better at bringing people together than what I would add myself.

Zierler:

It begs the question of course, you speak so warmly of your years at Exxon, why so short? Why such a short tenure?

Pincus:

It was mostly personal. I’m on my second marriage, now.

Zierler:

You got remarried pretty quickly?

Pincus:

A few years—well, maybe three years after my divorce. But somebody I knew from my UCLA days. Nola’s from Chicago but has become a big Californian. So our first winter in New Jersey is OK. It was nice and different for us. Also it’s not so bad because I have a big family in New Jersey. Remember I’m from New York, so I had a NJ aunt who had six kids, and they’re all—almost all still living in Jersey. My wife had a job. We were living in Westfield, which is like a suburb of New York, a bedroom community for Bell Labs, and at that time for Exxon as well…. not far from Newark. Nola had a job in a (kind of shady) lawyer’s office in Westfield and, as it turned out, she wasn’t too happy with her job. And at the same time, we were getting sick and tired of shoveling snow.

Also socially, while I had my family there, not—about 20 miles away up in northern New Jersey, it was difficult to make friends…we were already older and had no little kids….. The East Coast is not as friendly as California for people who come with no local family. It’s more of a inward looking environment. We loved New York, but at that time, our neighbors were afraid to go the city,….. you would get mugged. We lived in Westfield….. a short train ride from Manhattan, but none of our neighbors went. But we went fairly often. We liked it.

And at the same time, Alan Heeger and Vince Jaccarino were trying to convince us to come back to Santa Barbara. And we’re getting sick of winters. That was it. So finally we said, OK, maybe we should go back. When I left UCLA three years prior, I did something smart—not because I was smart, because I didn’t know what else to do—and that was not to close out my University of California retirement account. I had been at UCLA for about 20 years. When I left, I could take a lump sum of money, but I didn’t know what to do with it. I was ignorant in managing money, so I just left it in the system.

So as far as University of California was concerned, when I left UCLA, I was just on leave. So returning to Santa Barbara, I had just been on leave for three years. I just still had my 20 years. That made it a lot easier to return. We knew that there was good science by then at Santa Barbara, and we also knew that we really didn’t want to grow old living in New Jersey.

Zierler:

[laugh] Did you want to continue on with soft matter when you got to Santa Barbara?

Pincus:

I planned work some with Alan Heeger on conducting polymers and simultaneously build up soft matter at UCSB. I didn’t return to Physics at UCSB…I wasn’t up to their standards. At any rate, the best soft matter physics was being done by chemical engineers; so I joined Chemical Engineering at UCSB.

Zierler:

Yes, I’ve heard that before.

Pincus:

In my usual naïveté, I thought that all chemical engineers were like my Exxon friends Bill Graessley and Dale Pearson. In fact, they were atypical. But those were the chem e’s that I knew. So when I went back to UCSB, at the end of the day, it was more complicated to join Physics than ChemE. Also I was interacting with Bob Mehrabian, Dean of Engineering at UCSB, who wanted to create a Materials Department in the College of Engineering. So he suggested, “Why don’t you come to Chemical Engineering as a holding pattern while we move to create a Materials Department?” I realized that this was the right thing to do.

So I joined Chemical Engineering at Santa Barbara, and my first office was down by the UCen in what is now the Art Department. There was insufficient space in the one engineering building. I became a professor of Chemical Engineering. And only then did I learn that most chemical engineers were not glorified physicists. They were real engineers. Luckily ChemE had a great chairman at that time, Sanjoy Banerjee, who left several years later to City College of New York.

I recall that when I was first there, ChemE was recruiting someone who was just finishing his PhD in chemical engineering from Berkeley—who was doing polymer physics. From my point of view, the candidate wasn’t especially impressive and I couldn’t figure out why there was an interest in hiring him. The essential argument was that anyone obtaining his PhD in Chemical Engineering from Berkeley was good enough for UCSB. I went to Banerjee, and I said, “Sanjoy, I don’t think this guy is that good.” And he said, “Well, I agree with you. But the faculty is impressed because he’s from Berkeley.” But with my support, Banerjee went back to the faculty, the tide turned, and we didn’t ultimately make the hire. That seemed to start ChemE at UCSB moving to where it is now….a top 10 Chem E Department.

In parallel, Bob Mehrabian and his young co-worker, Carlo Levi, were very effectively creating the Materials Department, appointing outstanding faculty like Tony Evans, Pierre Petroff (Bell Labs), Evelyn Hu, Fred Lange, mostly working on ceramics and semiconductors, and me in soft matter. Shortly after, we convinced the fledgling Materials Department to appoint Cyrus Safinya (Exxon) to lead the soft matter biomolecule X-ray scattering effort. Cyrus and I were the original “softies”.

But then after a few years, I got the idea that I really belonged in Physics, not in COE. So I was able to move a fraction of my appointment to Physics; I became one-third in Physics, and two-thirds in the Materials. By then, I had moved out of Chemical Engineering, and eventually now I’m two-thirds in Physics, and one-third in Materials. The only reason Physics gave me a fractional appointment was because of Alan Heeger pushing. I really wasn’t good enough for them.

Zierler:

[laugh]

Pincus:

If I were them, I wouldn’t have hired me. But it was just a set of lucky circumstances. I was again in the right place at the right time.

Zierler:

Did it feel different being in a chemical engineering department? I mean, substantively, was there a different feeling to being, you know, anchored in that department as opposed to a physics department?

Pincus:

Sure. There were good people there, and I liked them but I wasn’t qualified to teach a lot of their undergraduate courses. I was only in Chemical Engineering for a very short time, a year or two, before I then moved to Materials. But I was too much like a physicist, even for Materials. Of course, the good thing about Materials was that it started as a graduate department, which it still is; this meant one didn’t have to teach engineering undergraduates. And then as I started moving into physics, I realized I liked teaching undergraduates better than I liked teaching graduate students.

I’m not really an engineer. I don’t think like an engineer, and I’m not interested in making better gadgets. I’m more interested in trying to understand how something works. Also I’m happier teaching undergraduates. I like to teach them, but they don’t like me.

Zierler:

[laugh]

Pincus:

I’m not viewed as a good teacher, and it’s mainly because of this—it goes back to this Kittel thing. I try to tell them that physics is not mathematics. For example, when de Gennes was elected to the French Academy of Sciences, he got into big trouble in France because in his inaugural lecture, he said, “You know, physics is not mathematics. The transistor was not discovered with theorems.” French teaching is very theory-oriented, very formal, and PG hated that. Well, that’s my teaching philosophy too. I never learned much from doing calculations. We learn things by understanding what the mechanisms are for what’s going on.

So I try to teach student to think physically. And for undergraduates—this is often difficult. What’s easiest for them to do is math because the good students are very good at math. They really know integral and differential calculus, differential equations, and nowadays, how to do computations. They don’t necessarily think about how to qualitatively apply the laws of physics to a given situation...this is much more difficult. So they hate me.

Zierler:

Why do you insist on that? What does that tell you about your approach?

Pincus:

I’m hoping that they will eventually learn to think physically which will help them in other endeavors. They hate me now, but I expect that won’t continue to hate me in 20 years.

Zierler:

That kind of sounds a little like your relationship with your own graduate advisor. [laugh]

Pincus:

Of course, of course, history repeats itself.

Zierler:

Fyl, just to bring the discussion right up to the present day, what are some of the things that you’ve been working on in recent years?

Pincus:

Whenever I work on something, I always get stuck in the first line because there’s often some assumption that I don’t understand. So much of my research is working on these “first lines”. Nowadays, a lot of what we work on in soft matter has to do with macromolecules, like polymers, and solvents. And nowadays, and one of the solvents that we like to think about and use a lot for practical reasons is water. But water is relatively poorly understood. And all of a sudden, I realized that I was having trouble because I didn’t understand anything about water.

So, for the last five years, I’ve been trying to think about water, about how it works; the chemists know an awful lot. But I want to think more like a physicist. For example, the cohesive energy of water is established by its hydrogen bond network. The quantum chemists can now calculate hydrogen bond energies to a “gnat’s ass”. But many of the important properties of water, like the hydrophobic interaction, are associated with correlations between hydrogen bonds. This is a physics type problem and together with Dan Hone, a retired UCSB Physics professor who was an undergrad at Berkeley with me, we’ve been applying Hubbard model thinking to this problem.

However, most of what I’m doing now is related to Debye-Hückel theory of electrostatic screening in electrolyte solutions. Well, as it turns out, it’s not that the theory is wrong, but rather its range of applicability. We’re been learning over the last two or three years, that most of the salt concentrations used lie outside of the applicable range. We’re working with Sam Safran (Weizmann Institute) and Susan Perkin (Oxford), trying to upgrade Debye-Hückel theory. So those are the things that we’re working on now. I’m at the stage in my career where I’m not writing as much as I used to because I don’t feel the need to publish so much. I’m just working for for my own edification. I’m only writing papers when I have a co-author who wants to publish it.

Zierler:

Fyl, what does it tell us that here we are in 2020, and you’re studying water? Like, at this point, we really still—there’s still fundamental things that we need to understand about water?

Pincus:

I think so. I think there’s a lot that we don’t understand. As I said before things like correlations between hydrogen bonds. Also, we often rediscover old papers that have lots of ideas that have been ignored……maybe the time wasn’t ripe. For example, one of the signatures of Debye-Hückel theory is that the Debye screening length is proportional to the square root of the salt concentration. That’s classical Debye-Hückel from the last century. It turns out there’s significant experimental evidence that that square root isn’t really right; yet it’s unquestioned. Experimental evidence for it is pretty meager.

It turns out that there were a couple of chemists in the ’50s from the University of Pittsburgh, Frank and Thompson, who suggested that the power law might be different, more specifically1/3 instead of ½ at multi-millimolar range. And then they gave results of their experiments on colligative effects which seemed to fit their model. This appeared in the Journal of Chemical Physics in the late ’50s. Now I think they were essentially correct. They didn’t have good theory, and our theory isn’t so good either. That’s science…..often rediscovering old ideas!

Zierler:

Fyl, over the course of your careers, you know, given your interests, your time at Exxon, have you ever been involved with research that had potential commercial applicability, or did you ever think about patenting any of the ideas that you came across during your research?

Pincus:

I’m not very good at thinking about applications. I don’t have that kind of creative skill to realize how something can be useful. But, of course, when I was at Exxon, we did consult with people in the company. I remember a team from Exxon Chemical who were working on a new type of artificial multi-component lube oil. “Look, we have this stuff. It really works well, but it looks like crap because you buy a bottle, and it’s phase separated. Is there any way we could fix this?” We were able to help them. But I was always on the fringe of that kind of activity. I never was very good at thinking about these things myself. I just didn’t have the correct mindset. This was never a talent that I had.

But I think, of course, it’s important for us scientists to be involved in these things. If we all do science the way that I do it, we would be funded at the level that art and music is funded. The reason that science is funded is because it does important things for mankind, but that’s not my forte. We piggyback on technology. Of course, we argue, with some truth, that we are producing enabling science.

Zierler:

Fyl, at this point, I think I want to ask, since we’ve brought your research up—right up to the present, for the last part of our talk, I want to ask you a few sort of broadly retrospective questions about your career, and then something that’s more forward-looking. And so, first, you know, thinking all the way back to your undergraduate interest in solid-state physics, what were some of the big mysteries in the field—either for you or generally, even for your mentors—what were some of those big mysteries or question marks in solid state in the late ’50s and early ’60s that you feel, looking back over the course of your career, are really well-understood now, and what are some of those questions that continue to endure, that have eluded, you know, something closer to a complete understanding?

Pincus:

OK. So I never was very good either at looking at the big picture. So when I was working on solid-state physics, I was—my goal at the early days was never to understand anything specifically. It was just trying to understand a particular experiment. I had small horizons. As you get older, your horizon broadens.

Oh, by the way, you mentioned when I was—as an undergraduate in solid-state—when I was an undergraduate, I actually specifically did not want to do solid-state physics because I was viewing solid-state physics as having to do with crystal structures. I could never see things in three dimensions. So I never wanted to work in solid-state physics. I was always thinking to be a high-energy physicist because I was better at dealing with mathematics.

But that—but only when I started graduate school, and I wanted to start doing research, I realized that if I wanted to do high-energy physics, I had to take field theory. But I was anxious to start doing research, and I hadn’t had field theory yet. I realized that the only kind of theory I could do without having field theory is solid-state physics. That’s why I started working with Kittel, and for no other reason—not because I wanted to do solids, I actually didn’t—

Zierler:

[laugh]

Pincus:

—but I was so anxious to start doing research. So what were the big problems? I think, as I’ve said in solid-state physics, anything you worked on was not understood. So we could work on anything, and there was no big picture. We were thinking like engineers, and we were thinking what do we do this next—answer this next question? For example, what happens if we put on a magnetic field perpendicular to the easy axis of an antiferromagnet? What happens?

We just didn’t know these things. So we were just asking sort of small questions. The big question at that time was what’s the origin of superconductivity? BCS was just coming out then. Superconductivity was the big unknown, and I would say that was the main thing.

Zierler:

And in terms of the kinds of things that are still not really well-understood today, what stands out in your mind?

Pincus:

The thing that stands out in mind for me is dark matter I keep telling people that I want to understand what dark matter is before I die. Closer to home, for me, a big challenge is understanding electrolytes. We still don’t understand them completely. And we don’t understand hydrogen bond networks. But the big question that I want to understand is dark matter.

Zierler:

Fyl, of course, dark matter is something that astrophysicists and cosmologists think about all the time. Is there anything that condensed matter physicists might offer to help solve this mystery of dark matter?

Pincus:

Well, yeah, I mean, of course, there’s a lot of condensed matter ideas. Does it have something to do with Bose condensation? There’s a lot of things floating around that other people are thinking about such as the role of magnetic monopoles and depletion interactions with antimatter.

Zierler:

And when you follow your nose, Fyl, what do you see, looking back over the course of your career? Are there any theoretical accomplishments that stand out in your mind as being the most significant for your field?

Pincus:

Yeah, I don’t know how you call my field, because I’ve worked in so many different things. But I was always looking over the shoulder of the people like Pierre-Gilles. The way that he would think about problems was a great accomplishment. For example, how to—how he thought about polymers. This was great. How Ted Holstein at UCLA thought about electron-phonon interaction. These were things that were blowing my mind. This were not the kind of science that I could ever do. People always say that they’ve learned by working at the shoulders of great people, and that is exactly me. I don’t feel like I ever did anything very important. I just looked over the shoulders of these unbelievably smart people. So that—and maybe if I had a strength, it was translating what they were saying into languages that other people understood.

Again, I’ll give you another example. When you’re talking with de Gennes about science somewhere or even in class, he would often say, “Oh, well, it’s obvious that ……” and he’d write something down. And more often than not, it wasn’t obvious where that came from. And most people, of course, didn’t know how to question this. But I was not afraid of showing my stupidity and I might say… “Well, I don’t understand. Where does it come from?” And he’d stop and look and then he’d say, “Well, I don’t really know, but it’s got to be this way.” And then he might say, “Why don’t I think about it?” Then about three days later, we would figure out that he was usually right. But great people often have this knack of knowing what the answer was without really understanding why. And I was good at translating what they said in ordinary people language.

Zierler:

And on the sociological side, you know, you emphasized, like, for example, your time at Exxon, bringing the right people in, and the fact that you have worked in so many different fields, what do you see as your sort of sociological contributions in terms of connecting people who in turn went on to do important research?

Pincus:

Well, I guess, there—I’d say there are a couple people that I think I had an influence on. One is Tom Witten. Do you know Tom?

Zierler:

I’ll be talking to him later this year. I’m very excited.

Pincus:

I met Tom. because he had once visited de Gennes who was very impressed with him. He was someone who was an assistant professor at Michigan who didn’t get tenure. He didn’t get tenure because the times were very rough then, and the department voted for the promotion but the administration didn’t give it. He wound up going to Germany and spending some time learning about renormalization group.

PG invited Tom to come spend a year at the Collège de France for one year when I was also there. Witten came to the Collège, we met, and I realized this guy was really good.. And he didn’t have a job. I explained what Exxon was trying to do and suggested that he might look into it. This was before I had actually thought about going. there. At that time, Tom was being recruited by Schlumberger. I didn’t think that “Schlum” was best for him because they had few experiments. Finally, I decided to go to Exxon and told Tom, “I’m going. Don’t you want to come too?” I think getting him to come to Exxon rejuvenated his career completely.

Witten and I did some good work together at Exxon, mostly me translating into ordinary language the things that he was saying , because, again, he’s a genuine genius. At Exxon—he did these important things on diffusion-limited aggregation, and he went back to the University of. Chicago, where he’s had a great career.

I also had some influence on Sam Safran, who, as I mentioned, is now at the Weizmann. He went to Bell Labs as a postdoc, working on intercalated graphite compounds. He got hired at Exxon independently of me. I didn’t know him.

But when he got there, and he started learning about what was going on, being a very smart guy, and he decided to study microemulsions. That’s about when I got to know him. I realized this guy is off scale smart, a great scientist, and a good guy. I became very friendly with him as well as with Tom Witten. And then Sam, working with Lee Turkevich, made a major breakthrough which had nothing to do with me. But I realized that this was terrific science and helped publicize it. This was real “Exxon Science” because the Safran-Turkevich microemulsion theory was based upon experiments by John Huang and Mahn Won Kim, both at Exxon, driven by issues in enhanced oil recovery. Sam moved later to become a Professor at the Weizmann Institute in Israel, where he spent a stint as Vice President. He continues to do tremendous physics there and we continue to collaborate.

Zierler:

Well, Fyl, for my last question, I want to ask you something that as I mentioned is forward-looking. And that is, you know, you can’t predict the future, of course, but using your powers of extrapolation, looking back on your many decades of research in all of these fields, what do you see as some of the most exciting research in soft matter, condensed matter, chemical engineering? What do you see as some of the most intriguing, important, impactful areas in theoretical physics and all of the other areas?

Pincus:

Of course, I don’t really know. One intriguing area that Tom Witten brought to my attention is neuromorphic computing. How can we do computing, like the brain does? Of course, a lot of people are working on it. But I think that this is an area that has a chance of becoming important. I think soft matter is maybe a better vehicle than hard condensed matter for the volatile memory because it’s closer to living things.

I think—again, I want to say something which is a little bit controversial where I will likely be proven wrong. When I was working in solid-state physics, I recall that Brian Pippard suggested that this field was being worked out. Metals and semiconductors were understood; there was BCS theory of superconductors. And then came high-T_c, solid state lasers… so he was proven wrong. I have sort of the same feeling today. Now I view condensed matter physics much as Pippard did in earlier times. I view it as a mature field. Of course, there remain many things to do. But it’s a bit like chemistry after the Second World War. It was mature. One could do things. But there are not major open questions. Where are the big open questions? They are now in biology, in astrophysics, gravity, and still in elementary particle physics. That’s where the big questions are. And what we’re doing in condensed matter physics, whether it’s soft or hard—soft is also maturing now—is we’re doing things which may be very important for technology... We still don’t have the “soft matter transistor”, but maybe we will.

So we’ll eventually understand completely how the energy is dissipated in tires and why they are amorphous materials. So there’re still lots of things that we don’t really understand completely… like fracture mechanics. Folks like Jean Carlson, Jim Langer, and Eran Buchbinder are making tremendous inroads there.

For me, the open science fields now are biology, neuroscience, astrophysics. And when I see great young scientists, I’m trying to steer them more into these directions. That’s where new discoveries about nature are likely to be made.

Zierler:

Why? Why do you think these areas?

Pincus:

Well, because there are big things we don’t understand at all. People like Roy Bar-Ziv at the Weizmann, working on synthetic biology, are trying to mimic nature with artificial systems. I just think it’s unbelievable. That’s how we’re going to understand how things work, again using the laws of physics.

As I said earlier, we want to understand what dark matter and dark energy are. We don’t really understand what’s on the other side of black holes. These are fascinating things. I also think that applied natural science is great too because it’s important for mankind as well as allowing us to pursue the probing of nature.

Of course, we have to deal with climate change. I don’t have anything insightful to add. But I do agree that mankind has no choice but to solve this problem if we’re going to survive. We have to use science to keep our planet habitable.

So I’m all in favor of all of these things, and we ought to be doing them all in parallel. I’m not working so much on those things, not because I don’t think they’re important. It’s because I don’t feel that I’m talented enough to contribute. I guess, as one ages, it’s increasingly difficult to learn new things.

So I’m working on the things which I think I could help provide understanding. I don’t view myself as a great scientist. You’re going to talk to Tom Witten. That’s a great scientist.

If you talk to Paul Chaikin, I mean, he’s one of the top experimentalists in any field because he’s somebody who could do theory and experiment, and he knows how to think. And there aren’t many great scientists like that.

Zierler:

Well, Fyl, on that note, it’s been so fun talking with you today, hearing all of your insight and perspectives from over the years. And, you know, like you said, you’ve been involved in so many different research projects across so many different fields. This is a record that I’ll humbly disagree with you. Lots of people are going to be interested in coming from many different disciplines, and so I’m so grateful that we were able to spend this time together today. Thank you so much.

Pincus:

OK, that’s great, and it’s fun to get all this off my chest. I also apologize for the rambling disconnected thoughts and anecdotes.

Zierler:

[laugh]