James David Litster

Zierler:

Okay, this is David Zierler, Oral Historian for the American Institute of Physics. It is August 5th, 2020. I am so happy to be here with Professor James David Litster. Dave, thank you so much for joining me today. 

Litster:

You're quite welcome. 

Zierler:

To start, would you please tell me your current title and institutional affiliation?

Litster:

Yes. My current title is Professor Emeritus at Massachusetts Institute of Technology. 

Zierler:

When did you go emeritus?

Litster:

I'm trying to remember. It was probably about 1975. That's when I started collecting my 401K.

Zierler:

But you've been involved with MIT ever since, in one form or another. 

Litster:

Yes. As emeritus, I still have a non-paying job there. MIT has a nuclear reactor, which happens to be in downtown Cambridge. Of course, it is something that, I suppose, makes some people nervous. There is a committee called the Reactor Safeguards Committee, which is made up of MIT people and a few people who are experts in the topic from other institutions, nuclear power plants and government laboratories. I happen to be the chair of that committee. 

Zierler:

Dave, let's take it all the way back to the beginning. Let's start with your parents. Tell me about your parents and where they are from. 

Litster:

My father was James Creighton Litster, who, like me, went by his middle name. My mother was Gladys May Byers. My father was born in 1907 in Langham, Saskatchewan, a small, you could almost say one-horse, town; the current population is about 1500. His father was the station master at a small railway station in Langham, which is about 35 miles northwest of Saskatoon on the Great Northern main line from Saskatoon to Edmonton. This was in the days before trucks. The way they dealt with the wheat in western Canada, where they grew it, is that spaced about a half a day to a day's wagon ride apart, they had these small railway stations on what later (in 1918) became the Canadian National Railroad. The train would stop, and it would pick up the farmer's grain, which they would drive in a wagon to the station. I've been to a couple of these stations, and I'm trying to remember whether they had grain elevators. They certainly had a way of storing the grain so the farmers could deliver it to be picked up. My father went to the University of Alberta and graduated in 1930, with a degree in electrical engineering. 1930 was not a good time to be a new graduate looking for a job. He actually got one working for Canadian General Electric in Peterborough, Ontario. My mother was born and grew up in Peterborough. CGE was a big company in the town at that time. It's still there, but it's not such a big player anymore. Anyway, he met my mother there, and I think not long after he got to Peterborough, he was laid off by General Electric. I'm about to tell you, perhaps, more background than you are really looking for, but you're too polite to say so. 

Zierler:

No, not at all. This is where it all comes from. Please.

Litster:

So, my father was laid off for a while. My mother had been to high school, but in those days in Ontario, there was a special program for women, of course, where they left high school at grade 10, having been prepared to be secretaries. My mother was a secretary with General Electric. Then what happened is, of course, my father didn't have a job, and it soon became apparent he wasn't likely to have one terribly soon. There was a special program they had in Ontario: if you wanted to be a high school teacher, you had to have a suitable degree. There was a rather small number of institutions that gave a one-year program to turn you into a high school teacher if you already had some appropriate education. My father decided that's what he would do. A great many of his colleagues did the same. As a result of that, there were a lot of engineers, and would be all kinds of other people too, who would not normally have chosen to become high school teachers, but because of the depression they did so. By the time I grew up and went to high school, these people were teaching people like me. Consequently, there was a whole generation of really highly educated people teaching high school in Ontario at that time. A lot of us benefitted from that. My father ended up not going that route. He was just about to get hired and take a job at a high school when CGE wanted to hire him back. He decided to do that, so he spent the rest of his career as an electrical engineer working for CGE. Any other things you might like to know for the background?

Zierler:

I'd like to know a little bit more about your mom's side of the family.

Litster:

Well, my father's side of the family was Scottish, and as a result, I'm 50% Scot. My mother's side of the family was half English and half Irish. Her maiden name was Byers, which sounds Irish, and they were Irish. My colleague, Bob Birgeneau, even though he has a French name, is definitely Irish. He always regarded me as having come from the wrong kind of Irish. My ancestors would march in the Orange Men’s Parade. We all thought it was funny. My mother’s father also thought it was funny. He had a dog that used to bark at the Orange Parade, and he said it was a Catholic dog.

Zierler:

Dave, where did you grow up? 

Litster:

A number of places because my father moved. He was in Toronto, working for GE when I was born. I think about the time I was six months old he was transferred out west to Edmonton, Alberta. So, I was born in Toronto, and I lived in Edmonton, I think until I was just a bit past four. We went out on the train. That's how you went out to the west in those days. My sister, who is four years younger than I am, was born in Edmonton. By the time she was six months old, my father got transferred back to Toronto. So, we each had long train journeys. Rather, my parents had long train journeys with young children—babies in particular. I don't remember too much about it. The main thing I remember is that you were not supposed to open the window and stick your head out, or if you did, you should keep your eyes shut so you wouldn't get cinders in them. These were coal-fired trains. 

Zierler:

Right. Where would you say you spent your formative years growing up?

Litster:

I think of formative years as probably when you're in high school. Before that, I remember when my parents moved back to Toronto we lived in Mimico, which is a western suburb of Toronto. Then, I think my father’s next job was in Toronto again. We lived next in a northern suburb of Toronto called Willowdale, which is probably part of Toronto now. I remember, when we went there, it would be about 1950, my parents had a house built on a street where there were still ditches running down the street for drainage. There was a movie theater on the corner of our street and Yonge. Yonge Street is the main north/south street in Toronto. It goes well beyond the city limits. We were about eight or ten miles north of Lake Ontario. At the corner of Yonge Street and our street, which was called Norton Avenue, was a movie theater where we would occasionally go to see movies. There were houses on our street that still had outdoor plumbing. The last time I was there was probably 20 years ago now, and there was a 50-story building where that movie theater used to be. 

Zierler:

Dave, when did you realize, perhaps, even before your formal exposure to math and science in school that you had a natural aptitude in these subjects?

Litster:

Well, I didn't look at it as a natural aptitude. I just looked at it as things I liked to do. I was sort of guessing you might ask me something like that as a question, so I thought back to see what I could remember. I was born in 1938, so I was three years old before Pearl Harbor happened. Canada got into the war before the States did, but it really wasn't having much impact on most people in Canada until after Pearl Harbor and the Americans got in. One of the things I remember was that when I was three years old, I got a cap gun. Those are perhaps not politically correct anymore. As far as I can tell, it didn't ruin me, and I even had caps for it. Of course, those things disappeared once the war got serious because the gun powder was all being used for something else. But I remember when I was three, taking that cap gun apart. It had springs, and screws, a trigger, and things. I just wanted to see what there was to it. I always wanted to understand how things worked and what they did, I guess. I wasn't thinking about that when I did it, but I took it apart and played with it and saw all the bits, and then I put the bits back together, and put it back together, and put all the screws in, and it still worked. So, I suppose, if I had thought about that, I might say I had a little bit of talent in that direction. But to me, it was just something I was playing with. 

Zierler:

In high school, did your school have a strong science and math program?

Litster:

Well, I think almost anybody who went to high school in Ontario in those days got a pretty good education. Maybe better in the English language than some of the—well, all the subjects were really good, but the thing that seemed outstanding to me, especially once I came to the States was the grade eleven English class we had. It really made a huge difference to us. We had a slightly different accent, but much about English we learned, people in the USA still don't know. I'm trying to think about the science in high school. I think we learned a lot more about things—there were other people there that were interested. Let’s back up a few years, and I'll tell you how the interest developed. For a while, we lived in Windsor, Ontario, just across the river from Detroit. Because things were a lot cheaper in the States, we would often cross the river to go shopping there. I remember we were in a department store over there. I don't know which one it was, certainly an American chain of some kind. (Edit: I recall it was J.L. Hudson) There was a toy you could buy your kids, which was a telephone. Of course, there were two ends. There were two handsets you could pick up and talk into. It had a battery in it, and it came with a spool of wire, so you could separate the handsets and talk. I was very excited about that, and I wanted my parents to buy it. As my father was an engineer, we weren't starving, but we didn't have too many extra pennies or nickels or anything larger. So, that didn't happen. We weren't in terribly bad shape because I remember we always had butter on the table, whereas my wife grew up in a family where they had margarine. 

Zierler:

You were much better off, if only from a gastronomic perspective. 

Litster:

Yes. So, anyway, I wouldn't say I made a fuss, but I continued to let it be known that that phone would have been a nice thing to have. Since my father worked at CGE, and about that time taxi cabs were just getting radios, and General Electric made the radios—this was before the transistor—they all had vacuum tubes in them and components like that. I remember the radio had a handset that the driver spoke into. It was just like the handset from an old black telephone that you probably remember seeing around the house when you were younger.

Zierler:

I do. I'm old enough to remember those. 

Litster:

So that's what the driver spoke into, and my father managed to get a couple of those. When radios were junked, he also managed to get a couple of those. He brought them home, and he had a six-volt dry cell battery of the kind that had these big cells—it had four one and a half volt cells that were like three inches in diameter, and about eight or ten inches tall, in a can. It was fairly heavy, but it was rundown. He brought that back and he found a transformer that somebody had junked. I was able to get wire out of the transformer by unwinding it. It was enamel-coated wire, and I had this six-volt, worn-out battery, but it still had a little oomph in it. The telephones didn't need much, and I remember with one of my friends, who lived about six or eight houses down the block, we ran a length of wire down the alley, from pole to pole, behind the houses. We had the battery, and we had the two handsets, and we used the water pipes in the house for the return line, and we could talk to each other. We loved to do that at night when we were supposed to be asleep. 

Zierler:

Dave, with your father being an engineer, I'm curious how much he involved you in his work. Did you have a good sense of what it meant to be an engineer? 

Litster:

I don't think so; certainly not a detailed sense. I'm sure I was aware that he was an engineer, and he obviously enjoyed his work. I think that was also about the time in my life when what I thought I wanted to do was to be a forest ranger. Later on, of course, he involved me more and told me a lot of interesting stories. If I think of it as I go further through this, one of them was fairly interesting, and I'll tell it. It's kind of interesting. I was sort of looking back on things as I grew up. My parents were not pushing me. I think there was a general understanding that I would go to university because my father had gone to university, but there was no pushing on it. The sense I have now, and I think it was probably true at the time, is whatever I found interesting and got excited about, they were supportive. That didn't mean they'd run out and buy me something expensive if I wanted it, just because they couldn’t, and they probably wouldn't have done it even if they could have. But otherwise, they were supportive. I never got screamed at or even lesser chastisement because I wasn't doing well enough in school or something. For no particular reason, I always seemed to do well in school. 

Zierler:

I rarely get the opportunity to ask Canadians this: you started undergraduate right at the time of Sputnik, and I'm curious if that had an influence on your and what you saw as your generation of up-and-coming scientists the way that it profoundly impacted so many of your American contemporaries. 

Litster:

I think it did. I was a freshman when Sputnik went up, and by that time I had a ham radio license, and my parents were in the process of moving from Toronto to Hamilton, Ontario. For that reason, instead of the University of Toronto, I ended up going to McMaster. There are some interesting things I can tell you about that when the time comes, but I remember I had built—encouraged by one of my father's colleagues at work-- I was kind of interested in electronics by then, and my father was an electrical engineer, but he was interested in 1000 horsepower motors, and things like that. He got one of his friends who was a ham radio operator, together with me. We spent a couple of evenings together and I learned an awful lot from him. Using what I learned from him, I ended up building my own radio receiver. What most hams did in those days was they bought a receiver, because it was a complicated project, and they built their own transmitters. This guy convinced me that his design of a receiver was much better than anything that you could buy. So, I built it, and I remember taking it with me when I started first year at Mac. At that point, my parents were still in Toronto, but I was boarding in a house near the university. I took the receiver with me to Hamilton, and because I had built it, it was somewhat flexible, and I could easily retune it to pick up different frequency bands. So, I tuned into Sputnik, and I remember the people I was boarding with, and others, we would turn it on, and they were quite impressed that they could hear the beep, beep, beep from Sputnik. By that time, it was clear to me that I wanted to get an engineering degree and then go to graduate school. I may be getting ahead of where we're going, or maybe not, but when the time came—I know I'm getting ahead because there's some things at McMaster that are interesting to talk about. But to apply to graduate school, I had applied to just three places. I had applied to the University of British Columbia, and this was to study physics. Sometime we can get into the reasons why I switched from engineering to physics. That was my safety school. Then, I applied for a Commonwealth Fellowship and wanted to go to Cambridge, and also, I applied to MIT because I had heard about it. It was supposed to be a good place. These were the three graduate programs I applied to. I got the Commonwealth Fellowship, which would have paid for me my expenses to go to England, but it wasn't to Cambridge. It was to Leeds, up in the northwest corner of England. I got into UBC but then I decided that MIT was a nice place to go. 

Zierler:

Let's go back to 1957. What were the scores you were looking at as an undergraduate, and did you know that it was engineering physics that you wanted to focus on? 

Litster:

I didn't know it was engineering physics. I knew it was engineering, and by that time I knew quite a bit of electronics. That was what led me into engineering. I only looked at two schools: University of Toronto, since we were still living in a suburb north of Toronto. That would have been close. I guess I thought about Queens, too, which was another good engineering school. In Ontario, at that time, there were basically three good universities: McMaster, which was a small Baptist college—I think it had 1200 students at that time; the University of Toronto, which was then the best university in Canada, and still thinks it is. It may even be right. And Queens, which is a very strong university in Kingston, Ontario. Then, of course, there was McGill in Quebec. I was thinking University of Toronto all along, but then with my parents moving to Hamilton, it seemed that it would be more affordable if I were in Hamilton at McMaster because I could live at home. So, I decided to investigate McMaster. McMaster, for years, had had a one-year engineering program—it taught the first year of engineering, and then the McMaster students all went for their remaining three years to Queens. It was a feeder for Queens, and that’s what I was thinking of at the time. But in the course of investigating, I also heard, probably from my high school guidance teacher, that McMaster was going to start a four-year program in engineering. So, I wanted to know more about that, and I actually called up the engineering department on the phone. It was answered by the man who was going to be the dean of the new engineering school. We had a long conversation, and it seemed to me like it made a lot of sense to go to McMaster. 

Zierler:

I've learned a little bit about different programs that went by the name Engineering Physics. In the case of McMaster, what was the rough split on the engineering side and the physics side?

Litster:

Well, you have to understand, we were the first four-year class that they were putting through. So this was, to use the euphemism, a work in progress. Basically, it was an electrical engineering course, but in the first couple of years it was pretty broad. We all had chemical engineering, mechanical engineering, and electrical engineering courses. All engineers took drafting in their first year, and there were a lot of people, even the architects that planned the house we're living in here in California, that were quite impressed when I told them I had taken drafting, and that we had done drawing with ink on vellum as undergraduates. And we took surveying, so we took all of those things that are not part of current engineering curricula. And then we added a few math and physics courses to it, and they called it engineering physics. There weren't many engineering physics programs, I think, in the States at the time. I recall Cornell had one, but most other US universities, if you mentioned engineering physics, they didn't have it. 

Zierler:

I know at Cornell, engineering physics meant that it was just about as much physics as the physics majors themselves took. 

Litster:

Yes. I think it sort of got that way at McMaster, but because this was the first year that they were doing, and we'd been through it, it was getting probably into the third year before they realized we weren't getting as much math or physics as they thought we should have. They then worked hard to add more of that. I would say the most valuable part of my education at McMaster—I was going to tell you this story, and I'll tell it now—actually came from the dean. When I got there, there were 25 of us in the first engineering class, and I think there were two women. The dean was a chemical engineer. He had a lab on campus. When they hired him as dean, he said he wanted to keep doing his research. He had worked for the National Research Council in Canada during the Second World War, working on chemical warfare and related topics, so he knew about those things. He wanted to have a lab on campus, and there was no engineering building at the time. That was just starting construction, so we were scattered all around with all the other science majors at the university and took a lot of joint classes with them. Maybe that's why they didn't think they had to give us special courses for engineers. The dean discovered that being dean, he didn't have the kind of time that he wanted to spend in the lab, but he didn't want to see his research run down. He actually offered me a summer job at the end of my first year. I guess after the first year he figured out maybe that I was a person he could trust in his lab, or something. That was actually in another building called the Nuclear Research Building, which is where all the nuclear and other physicists had laboratories. Bert Brockhouse ended up there, although I had graduated by the time he arrived at McMaster. Anyway, it was a pretty good place. The dean being so busy administering, I sort of did what I wanted to in the lab, except of course, he had a research program that I was working on that was his idea. But I got to know a lot of physics graduate students and other people, although I was still a freshman. That was kind of interesting, too. But the project the dean had was measuring the effect of sonic energy on mass transfer. That was the title of his research. It's simple to explain. He had what the chemical engineers would call a wetted-wall column. It was just a hollow Pyrex tube, about a bit over an inch in diameter, and maybe five or six feet long. Up at the top of it, you had a nicely square-cut end, and you put water around it. If you did, it could just run down in a nice uniform film on the inside of this Pyrex tube. Then you could blow air up through the tube against the water, so you had a counter current flow, and you could measure the evaporation rate of the water by measuring the humidity of the air when it got up to the top. What the dean wanted to do was to enhance the evaporation by providing strong, powerful sound waves inside the tube. So, we had—you probably remember seeing these sound trucks that used to go down the street with a speaker that was a couple feet in diameter. Well, he had the driver for one of those. It was probably the size of a grapefruit; if you put it on the input of the speaker horn, it drove things to make the sound. So, he had one of those drivers that he put on one end of this wetted-wall tube, and we could tune the frequency applied to it so it was at a resonant frequency of the space inside the tube, and we could see what the effect was on the mass transfer. I got that set up but not quite working over the first summer. Then the dean hired me to continue on it working on my own, part-time. I recall it was actually for the next school year, the summer after that, and at that point I got other jobs. But he finally got a paper out of it and published the results. He also got a patent on it. It turned out that patent was something that the Americans needed in order to design and run their solid fuel rockets. You can see how there might be a relationship between in the two. In fact, that's how solid fuel rockets work. Almost everything that goes on inside the rocket while it's burning is essentially based on the things that Dean Hodgins learned from that research. 

Zierler:

Dave, I wonder if your decision to pursue physics coincided with the program, as you said, a work in progress, as it realized that it needed a stronger basis in math and physics? I wonder if there was a coincidence there?

Litster:

I don't think that was the reason. I don't think it was until I got to MIT that I realized how weak my mathematics background was. 

Zierler:

But when you were thinking about graduate programs, it was specifically in physics. You consciously decided to move away from engineering. 

Litster:

Yes, and that was the question you were heading for. I'll tell you why I made that decision. I made it for somewhat different reasons. How can I put it? Engineers are very practical people. What they want to do is solve problems. They know you have to understand the problem, and enough of the science behind the problem in order to be able to solve it. At least, good engineers do, which I think most practicing engineers do. I thought that was fine, but the other thing engineers like to do, once they've solved a problem, then they want to solve another problem. I didn't think they wanted to understand things they were working on as quite as deeply as I wanted to understand them. That's why physics attracted me. 

Zierler:

Not only physics, but it sounds like also from an intellectual perspective, you wanted to pursue a more scholarly path of intellectual inquiry than simply the question-and-answer mode of engineering problems. 

Litster:

Yes. I didn't think of it as scholarly. I just thought of it—anything I'm involved with, or was even when I was in short pants, I wanted to understand it as deeply as I could. 

Zierler:

I wonder, did you look at MIT as an opportunity in and of itself, or were you thinking more broadly: “Well, if I'm considering MIT, there's a whole host of schools in the States that I might consider”?

Litster:

I don't think I considered it that broadly. I think that I was interested in a very good engineering school, and there weren't that many in the States at that time. I could have thought of Cornell. I wouldn't have thought of Harvard. I think most Canadians had a fairly limited grasp of what the opportunities might be in the States. This is getting into something that I might say later, but I'll say it now: at that time in Canada, there's a couple of interesting things about Canadian culture. I'm speaking of English-Canadian culture now. First of all, modesty was a virtue. My Canadian friends at MIT—actually, there were several other Canadian friends at MIT. At one time, there were about eight Canadians on the MIT physics faculty. We used to have arguments at Bell Labs as to who would have the best Canadian physics department. MIT or Bell Labs? I'm not sure we ever resolved that. Anyway, I remember discussing this with Bob Birgeneau. We both agreed modesty was a virtue in Canada; we also agreed that we think each of us overcame it. I just wanted to pick some interesting places, but I don't think I was paying a lot of attention to what my career path might be. I was more just driven by wanting to learn things and how to do things and understand things. I guess I just subconsciously felt that if I succeeded moderately at that, everything would be okay. 

Zierler:

Once the MIT possibility became available, that was a very easy choice for you, ultimately.

Litster:

Certainly, between MIT and the University of British Columbia and the University of Leeds, it was an easy choice. Had the Commonwealth Fellowship offered me Cambridge, it might have been a more difficult choice. Of course, much later, MIT and Cambridge, as you probably know, formed a bit of a partnership. I was VP of research at MIT at the time, and I was involved in that. I realized that I was very lucky. Had I gone to Cambridge, it would have been a mistake for me. 

Zierler:

What were your impressions when you first got to MIT? Did it feel big? Did it feel foreign?

Litster:

It did not feel foreign. You know, the Boston accent is slightly different than Ontario, but not much. It was bigger, because McMaster's background is-- You probably know this about English universities. The different colleges tended to be associated with some branch of the Christian religion. University of Toronto was, for example. Bob Birgeneau was at St. Michael's College, and if you were Roman Catholic, that's where you went. But the Baptist college had split from the University of Toronto sometime in the early 20th century and gone off and founded McMaster. I don't know what the history of that is. It happened long before my time, but it began as the Baptist college from University of Toronto. When I got there, they had just this one-year engineering program, and then they had chemistry and physics. One of the other classes I had to take as a freshman, besides surveying and engineering drawing, was comparative religions. That was taught by the president of the university, who was a Baptist minister. I remember taking that. It met one day a week, I think, and I went to all of the classes because it was interesting. It was worthwhile, because the way things worked in Canadian schools at that time is you had a final exam at the end of the school year. What you did on that determined whether you passed or failed. Homework would be turned in and graded, which was to let you know whether you'd done a good job on it. It didn't play a part in your grade. There were no quizzes during the class, or anything like that. It was entirely the final exam. Classes would end, and then there'd be about a week or ten-day period before the exams were given. The tendency was to have a great time for the school year. I do remember I learned how to shoot pool pretty well as a freshman. And then there would be panic between the end of classes and the appearance of the final exams. I was at home studying for the exam in comparative religions, though I probably didn't study too hard for that one, but I was preparing for my exams anyway, and a couple of Jehovah's Witnesses knocked on the front door. I was somewhat prepared for them, and we had a wonderful argument for probably about an hour, but they didn't convert me. 

Zierler:

Dave, when you got to MIT, how well defined was your self-identity as a physicist and the kind of physics you wanted to do? Even baseline questions about experimentation or theory, did you have an idea of what you wanted to focus on, or who you might want to work with?

Litster:

It was very clear that I wanted to be an experimenter. I've always liked to do things with my hands, since that cap gun at three years old, so I don't think there was any doubt about it. I wanted to be an experimenter. By that time, I thought that the area of physics that I would find most interesting was solid-state physics, which is closer to engineering than string theory. MIT cost money, of course. At that point, since it was post-Sputnik, four years after Sputnik, the US government was looking for any excuse to pour money into universities. There weren't more than about a dozen that it thought were worth pouring money into, in terms of their science and engineering. It was probably mostly engineering expertise that they cared about. So, MIT didn't have a ton of money to support students, but they had lots of research money. You've probably talked to enough MIT people that you know exactly how it worked. I had a research assistantship in the Laboratory of Chemical and Solid-State Physics, which John Slater was the director of at the time. When I got to MIT it was in early September, and I went to see Slater, to find out how this research assistantship meant I was going to work in some research group. That was going to pay me enough money to pay to eat, and perhaps a bit more. Actually, the way it worked, I got paid to eat, and MIT got paid tuition for the rest of it. I remember, before I went to see Slater to discuss which research group I might join, I had already been at MIT for a day or two. I remember eating in Graduate House, now called Ashdown House, named after Avery Ashdown, which was the graduate residence. I would sit down at the dining room tables and talk to the students, especially students who had been around longer than I had, to find out what was going on, and what courses I should take, and so on. I got a lot of information that way. Then I went to see Slater. He asked me a several questions about things to see what I was interested in and where I should go. I remember, at one point, after telling me a number of things, he asked, “Do you have any questions?” I said, “Yes. I need to take a course in quantum mechanics. I've never had a course in quantum mechanics.”

Zierler:

Dave, the fact that you were asking about quantum mechanics, to what extent can you extrapolate from there that you were not nearly as prepared as some of your fellow students coming in?

Litster:

Well, that's where the extrapolation started. I can give you a little bit more information later how I really knew it. Anyway, there were two courses in quantum mechanics. One was taught by Slater, and one was taught by Felix Villars. You're not a physicist, so I won't name the two different textbooks they used—you're probably not familiar with them. But the Felix Villars course, I didn't know at the time, but I now know was much more mathematical, and was a good course. Slater's courses were also good, but different. Of course, I had been told by graduate students that I met in the dining hall that Slater's course wasn't very good. It didn't have a good reputation. These were students, of course, who had never taken it. They'd taken Villars's course. So, I asked John Slater, “There are these two courses, the one you teach, and the one Professor Villars teaches. I'm trying to decide which one to take.” He asked me, “Have you asked other students about it? What did they tell you?” And I told him. As I mentioned, I'm 50% Scottish, and the Scots are fairly frank when they speak about things. I didn't know at that time that Slater had a reputation as someone with a terrible temper, so I didn't realize how close I was coming to death. He listened to what I had passed on, what I had heard from the students. When I had finished, he said, “Well, they may have a point, but you should take my course.” And he was right, of course. I would have flunked the Villars course. 

Zierler:

That was good advice. 

Litster:

Another indication that I wasn't well-prepared mathematically was in the graduate course in electricity and magnetism, which Earle Lomon taught. Earle is still a good friend. But at the time, I remember fairly early in the course, he was talking about something called Stokes' theorem, which is a mathematical theorem about doing a line integral of a vector field around a curve and relating it to the curl of the field integrated over the enclosed surface. I'd never heard of it. So, I knew I had something to make up. 

Zierler:

As you were gaining your sea legs, how did you go about determining who your graduate advisor would be, and how would you develop your dissertation topic? 

Litster:

That happened shortly after meeting Slater, very early in the term. He gave me a list of the faculty, knowing I had condensed matter and solid-state interests. Condensed matter hadn't been invented as a term yet. He told me which professors might have openings in their research group. So, I went around to see the three or four of them. The professor I settled on was George Benedek. George had just come from Harvard where he—I didn't know all of this stuff at the time—where he had not been granted tenure. Have you ever interviewed George?

Zierler:

No.

Litster:

It's too bad, because a few years ago he had a stroke, and it really affected his speech. That's lost now, I suspect. He's still alive. Anyhow, the person who was granted tenure at Harvard instead of George, I'm sure you have interviewed, so I won't tell you his name. George then got a job at MIT. MIT benefited greatly from Harvard’s decision. George made far greater contributions to the intellectual development of physics than some that Harvard kept. Anyway, it was a very hot day, in the 90s, in September. George had a window air conditioner in his office and his lab, which was right next to it. That sort of started me thinking he's the right guy. But of course, I talked to him about physics things too, and I thought this guy knows what he's doing, and he doesn't screw around. The other people I talked to were not such good salesmen. So, that's how I picked George. I've kidded him since and told him I chose him because he had an air conditioner. 

Zierler:

That's funny. 

Litster:

He thought it was funny, too, which is good. Sometimes I say things that I think are funny and other people don't. 

Zierler:

In terms of developing the dissertation, and more broadly, the kind of relationship that you had with George, did he essentially give you a problem that was related to what he was working on, or did you come up with a topic more or less on your own?

Litster:

He gave me a problem. That's almost always the way it goes. It may not be a specific problem. It may be an area, or “I think this would be interesting.” The only person I know at MIT who did it the other way around, and he did it with a Nobel Prize winning supervisor, turning down the problem he was given and saying, “No, I want to do this.” That's David Moncton. Have you interviewed David?

Zierler:

I have not. Not yet. 

Litster:

You should. He's a good friend. He and Birgeneau were serious rivals about a number of things. They're very different people. Moncton is a much better engineer. Bob Birgeneau is not really an engineer, but he's almost always the one who, when an experiment starts producing data, he figures out quicker than anybody else what it means.

Zierler:

What was George working on at that point, and how was that related to the problem he gave you?

Litster:

George had done an interesting PhD in Harvard. Essentially, he had Percy Bridgman and Ed Purcell, each Nobel Prize winners, as co-thesis supervisors. George was an experimenter, so that's the Bridgman part, and it was high pressure. Purcell, of course, had his Nobel Prize by then for the discovery of nuclear magnetic resonance (NMR). And what George was doing was NMR at high pressure. That was his work at Harvard. That's the work that Harvard didn't give him tenure for. So, he came to MIT and he continued doing that. The first thing George wanted to do and suggested I work on, not necessarily as a thesis—I don't think it was a thesis project, but it would have been a good start—George knew that I knew some electronics. It was all done with vacuum tubes at the time, of course. He wanted me to build an NMR spectrometer, and then he said what he would really like to know—he had done NMR with iron, using the iron 57 isotope, which has a nuclear magnetic moment. With iron, there's a very strong magnetic field at the nucleus of the iron atom. The iron atom itself has a magnetic moment. Of the two 1S electrons, which are the two core electrons of the iron atom, one has spin up, and one has spin down. Because of the magnetic dipole moment that the atom has due to outer electrons on it, the density of those two core electrons near the nucleus is slightly different. That produces a magnetic field, called the hyperfine field, at the nucleus of the atom, which is about 300,000 Gauss, if I remember. That's 600,000 times the Earth's magnetic field. Iron 57 had a nuclear spin, so you could do nuclear magnetic resonance by flipping that spin if you put the right radio frequency into it. George, when he was at Harvard, had measured the pressure dependence of that NMR frequency as you squeezed the iron. Squeezing changes the electrons slightly at the nucleus of the atom. He wanted to continue that, but at Harvard he had a hydraulic press to make the pressure. You could get up to about 10,000 atmospheres with it; that was the most. At Lincoln Lab, they had a different kind of press called a belt press. The belt was a thing kind of like a donut, with a hole in the middle of it. Then, you push two tungsten carbide pistons into the donut hole with something between them, and if you push them in hard enough you've got very high pressure. That apparatus was actually developed at General Electric when they still did research. They used it to make diamonds; they made industrial diamonds with it. Lincoln Laboratory had a belt press, and George thought it would be interesting to do this iron nuclear resonance experiment to higher pressures. So, I built the NMR spectrometer, and I spent essentially the first semester I was at MIT out at Lincoln Labs doing NMR inside this belt pressure equipment. We were able to measure the NMR frequency as high as the press would go, which was about 65,000 atmospheres. So, that was the first project. George had had a student at Harvard who was very interested in magnetic phase transitions, and how you take something like iron and cool it down and it becomes a ferromagnet – and study how that took place. So, that's what led into this whole business of phase transitions. George’s student at Harvard was Peter Heller, whose thesis involved using NMR to study magnetic phase transitions. He brought Peter to MIT with him as a post doc when he was setting things up. That's how the Benedek-MIT group got into phase transitions and nuclear resonance. My thesis was to be in this area. I have never published my thesis, by the way -- not too many people have never published their PhD thesis. It was publishable, it's just that somehow, I got involved in other things and never got around to writing it up like I should have. Anyway, my thesis was nuclear magnetic resonance in yttrium iron garnet, which was an electrical insulator. We were very interested in that hyperfine field I mentioned, with 300,000 Gauss at the nucleus. As the magnetism gets established in the material, as you go through the phase transition, that hyperfine field changes, and you could use it to measure the temperature dependence of the magnetization. I sent you this page of notes on the mean-field theory. Mean-field theory is wonderful. It's good physics. It's Landau. Landau was a very smart, intuitive person, very much like Pierre de Gennes was. He thought understanding magnetism was a complicated problem to solve. He said, essentially, “I know that if I were a single atom inside, say, iron, I will have an impact on all the other iron atoms in the crystal. It's all these atoms interacting together that make it become a magnet. I don't know how to calculate this. It's extraordinarily complicated.” In fact, it's a problem that is yet to be completely solved in physics. (The three-dimensional Ising model, for example, has not been solved.) Anyway, Landau thought, “I'm going to pretend that all those other atoms, whatever they do, make some kind of an effective magnetic field at this single atom that I care about. I'm going to assume that effective magnetic field is proportional to the average of what all these other atoms are doing. But all the atoms are the same, so if I can solve the problem of this one atom in the average field that all the others produced, I have solved the problem.” That was what he did on the page of notes that I gave you. The generic problem was that any phase transition is a competition between entropy and internal energy. The entropy enters in the equation of state because it gets multiplied by the temperature. So, that means, whichever wins that competition, depends on the temperature. If you go to high enough temperature, the entropy is going to win, and the system is going to be disordered. That's the physics idea in Landau's Mean-field theory, and that was the calculation in the paper. But he didn't go to the next step, which is: because you've got temperature, every degree of freedom has kT of energy in it, hence there are fluctuations. It turns out that as you get closer and closer to the phase transition, the fluctuations take over and they become so big that it doesn't make sense to talk about the average of what the other magnetic atoms are doing, because there's so much fluctuation going on. It's saying if the RMS fluctuation is bigger than the mean, then the mean doesn't make any sense. That's the physics behind everything that Bob Birgeneau and I, and lots of other people, worked on. 

Zierler:

Dave, I don't know if you were thinking such grandiose thoughts at the time, but looking back, where do you situate this research within some of the broader questions that were being raised in the field?

Litster:

The phase transition stuff, for example? I would say it was pretty clear it was important even before I finished my PhD. I came to understand a lot more about how important it was and why it was important from talking to George. And, one of the great things about MIT is you have visitors from all over the world come to talk to you. They want to know what you're doing; you hear what they're doing, and you exchange ideas. So, it was pretty clear to me by 1963 or so that this was important. It was probably clear to lots of other people before that. 

Zierler:

In terms of the advice that you might be getting about next steps, did you consider post docs beyond MIT, or were you just so happy and it was all set up that it seemed like the best course of action to stay on at MIT and continue teaching and researching?

Litster:

At the time it seemed to me it was the best course of action, and I still think, in hindsight, it was. But I did ask myself that question and think about it. The other question was, as a Canadian, am I going to go back to Canada? By that time, I think I wanted to be a professor. When I started MIT, I hadn't a clue what I wanted to do. I knew it was not a forest ranger anymore, but you reach stages in your life where people start calling you up because they're interested in you, or something, and there were people in Canada who wondered if I would come back to Canada. I got an informal job offer from Simon Fraser before I finished my thesis, I recall. Simon Fraser was a new university being established in Vancouver. One of the other things I thought about was a post doc at the University of British Columbia or something similar. I mentioned these to Avery Ashdown. He was the master of the graduate residence at MIT (now called Ashdown House), which I lived in for the first year or so when I was a graduate student. He was a chemist. He was younger than I am now, but he was a retired MIT Professor at the time. His contribution to the intellectual development of science was essentially that he'd done important work in the discovery of polymers. I remember him telling me stories from when he was a graduate student. All the chemists laughed at him. “How big are these molecules? Oh, come on!” But I remember several conversations with him. He formed a little group, which was about eight or ten of us, who lived in the Ashdown House. We were called the Cherry Pie Club. We would get together once a month and have dinner, with cherry pie for dessert. One of the group was charged with giving a talk to enlighten all the other members of the group about some topic of his own choosing. Anyway, I remember talking to Doc Ashdown about the future, and he sort of looked at me and said, “Never leave MIT.”

Zierler:

Well, you certainly took that advice. For your first position, you were not officially on the faculty yet. 

Litster:

Yes. I'll tell you exactly what happened. George Benedek wanted me to stay as a post doc and work for him, and I was going to do that. MIT has long had this physics department policy that the recitation sections would actually be taught by faculty, not by graduate students. (I think it may not follow that 100% anymore.) Bill Buckner, a nuclear physicist, was the head of the physics department at that time. I think he was a little shy of the manpower to teach recitations, so he wanted to appoint me as an instructor so I could teach some recitation sections. So, that's how my academic career started. There was a little bit of friction there because the department offered me a salary which was less than George had offered me as a post doc. So, I said to Professor Buckner, “Well, I can make more money spending all my time on research as a post doc.” The department had to match the salary, and then I thought teaching would be interesting because I liked teaching. 

Zierler:

Had you done any teaching as a graduate student?

Litster:

Nothing official, no. It had all been 100% research.

Zierler:

What courses did you want to teach, and how did you see that relating to what would ultimately become your teaching niche in the department as a faculty member? 

Litster:

Well, if you look at the courses I taught, some of the more interesting ones were graduate courses. In fact, there was one I think you know about: after Peter Wolf and Bob Birgeneau had come to MIT—my favorite course was this one, but by that time I'd been there and had tenure. Peter Wolf, I, Tom Greytak, Bob Birgeneau, and Jens Als Nielson (who was visiting from Copenhagen)—we decided we were going to teach each other what we knew. We could see that our research interests were converging. That's what we did. We spent a semester teaching each other what we knew. The students in the course were allowed to watch.

Zierler:

This must have been informative for both of you. 

Litster:

It was informative for all of us. Teaching has always been informative for me. You think you understand something until you try to teach it. 

Zierler:

Sure, absolutely. 

Litster:

I started off teaching freshman recitation sections. That was interesting too. I remember one where Pierre de Gennes, whom I had met at a Gordon Conference by that time—this would have been later on after I was interested in liquid crystals. So, that's how I got involved with him. Anyway, he had come to Harvard to give the Loeb lectures, and he was interested in amino acids and things like that. I remembered something from his Loeb lecture. I think it was the fact that in nature, all the amino acids are—I don't remember now whether it's right or left-handed. You probably know. I knew, and it'll come to me tonight sometime. I just happened to mention this in freshman recitation section where we were actually talking about classical mechanics, the 8.01 course, but I always liked to tell them something interesting at the beginning of the class before we got into how they did their homework. So, I mentioned natural chiral amino acids were left-handed, and I heard this stage whisper from the front row, “Bullshit.” So, I ignored it, and I heard it again, and I stopped, and I said, “Okay, what's that all about?” He said, “It's not true. There are bacteria that use the opposite chirality of proteins in their cell membranes, so they can't be digested by other bugs that want to eat them.” I thought, gee, this is great. This is why I like to teach MIT students. And then I went on with the class. However, I just happened, several months later, to open a copy of the freshman biology book, and there it was on the first page. So, that tells you something else about MIT students. 

Zierler:

Right. Dave, when did you decide to really take on new areas of research beyond this initial work and your graduate school days? Was that a gradual process, or did new ideas come to you and you took them on full speed?

Litster:

I think it was gradual. I would look at all of it and say was just an adiabatic evolution of what I was doing. It wasn't that different. The things that I did in liquid crystals were not that different—we were looking at the same kind of problems that we were looking at when we were doing NMR in yttrium iron garnet, or other materials. 

Zierler:

How did you develop that line of inquiry?

Litster:

Well, it started with magnetic phase transitions, and that was in George's lab. He wanted me to look at it, and Peter Heller was there, who taught me about magnetic phase transitions and other things. It was clear at that point, from Peter's research, that the Landau model didn't work. It was qualitatively correct, but there was something else going on. So, that's what led to all the interest in it. I think by the time I got interested in liquid crystals, I would have gone a little further and said, well, another reason these things are so interesting is that they're an ordered phase which is in between a liquid and a solid. Everybody would love to understand melting. At that time, and I would say in three-dimensions it's still true, the most intelligent thing anybody ever said about melting was Lindemann who was Churchill's science advisor in the Second World War. Have you ever heard of the Lindemann rule? It's very simple and it'll make sense to you. It doesn't answer any questions very quantitatively, but it tells you what's going on. He said the lattice is vibrating, so you've got all these atoms there, and the atoms are all bound in a crystal lattice. That keeps them from moving very far, and as they're close together, they can't get past each other. But once they start vibrating, and once you get enough phonons excited thermally, from time to time in a region some atoms occasionally get far enough apart that another can slip through a hole between them. That's when it melts. And then Lindemann thought this way—you can look at Debye theory of phonons in a solid, and see what the root means square (RMS) fluctuations of the atoms about their equilibrium position as a function of temperature is, and when does it get to be large enough—and then you can look at the melting temperature, and in fact, they're all correlated. You have to heat something enough so that the RMS positional fluctuations of the atoms is a certain fraction of the average distance between them; that's where the solid melts. The higher that temperature is, the higher the melting temperature. In two-dimensions the melting problem has been solved, but nobody has yet done the statistical mechanics well enough in three-dimensions.

Zierler:

I'm very curious about your visiting faculty appointment at the Watson Research Center. How did that come about, and what kind of work did you do there?

Litster:

That was liquid crystals. That came about just when I—at that point I had done the experiment that showed if you took a nematic liquid crystal in its disordered, isotropic phase, and cooled it towards the nematic phase where the molecules are all going to line up parallel to each other, that it behaved the same way, in many ways, like when you take an iron atom material, and all the magnetic spins are pointing in any old direction, and you cool it down, you get a Curie temperature where they all line up parallel. So, I did some experiments that showed how the nematic to isotropic transition in liquid crystals was the same kind of statistical mechanical problem as the magnetic ordering transition, or the liquid gas critical point—all these problems that we were trying to understand. The difference was the symmetry. Thus, in my view, geometry is what determines everything. To see the difference, consider a ferromagnet. At a magnetic critical point, the order parameter is a measure of the parallel alignment of the magnetic dipoles in the material. Each of these dipoles is like an arrow; it has an up or down. Thus, changing the sign of the order parameter corresponds to turning all of the magnetic dipoles to point in the opposite direction. What that means is that the order parameter in a magnet has dipolar symmetry. It's like a dipole, and if there is no external magnetic field positive and negative order, parameters are equivalent. In a liquid crystal, the two ends of the molecules are actually different, but that difference doesn't matter. They're equally likely to point one way or the opposite way, the way they interact with each other. In a nematic liquid crystal, the molecules want to be parallel but they are just as happy if they are antiparallel. That means the order parameter has quadrupolar symmetry, which in turn means that a positive order parameter has the molecules parallel, and a negative order parameter means they are all randomly oriented in a plane. Then, if you do Landau theory—and this is what de Gennes explained to me—if you do a Landau theory of that, and you expand the free energy, you have to have cubic terms in it. As soon as you do that, bingo. You have a first order phase transition, but it looks like it's going to be second order until it gets very close to the phase transition. So, I had done an experiment to show that. There was a physicist, Dale Teaney, who worked at IBM, and who had visited the Orsay group in France. (De Gennes had started a group to study liquid crystals at the Orsay campus of the Université de Paris.) They were looking at the normal modes of nematic liquid crystals. They weren't thinking about the phase transitions. The normal modes of a nematic liquid crystal are the analog of spin waves in a magnet. These are all predicted by Goldstone's theorem: whenever you have a spontaneously broken symmetry, there's a normal mode that attempts to restore that symmetry. Anyway, Teaney had seen what de Gennes’ colleagues—de Gennes was then a theorist at the Collège de France—and Dale wanted to start liquid crystal experiments at IBM. That’s why they invited me to come to IBM for a summer. 

Zierler:

Dave, in what ways did working in those environments differ from what you were able to do in an academic setting?

Litster:

At IBM it wasn't much different. IBM and Bell Labs were both similar—the difference between either of those places and a university was that in a university you had to teach, so you couldn't spend 100% of your time on research. Whereas, at IBM and Bell Labs, you could spend 100% of your time on research. However, IBM was a little more practical and Bell Labs was perhaps more academic in some ways. Did you ever hear the story about how Unix was developed? That's a great story, too. Kernighan and Ritchie, who developed the C programming language and wrote the first book about C, also developed Unix, and were both graduate students at MIT in the computer science section of the EE Department. MIT, at that point, had just developed a time-sharing system. That's where time sharing in computers came from. Fernando Corbató, I think, was the professor who was in charge of it. Anyway, they picked the name Multics to describe their software, because it was an operating system where you could have multiple users at the same time. Then, Kernighan and Ritchie were hired by Bell Labs, I expect because that had been part of their thesis work. When they got to Bell Labs, an industrial lab, they asked in effect “What do you want us to do?” And—this was typical Bell Labs—the answer was along the lines of “Do something good.” So, they thought a bit, and hunted around, and happened to find in somebody else's lab a little DEC PDP 11 computer, which wasn't being used. They decided, “Let's make that do time sharing.” So, they developed time sharing on a PDP 11. Then, they decided they had to give their operating system a name, and since it was much smaller, they called it Unix, instead of Multics. That's where the name came from. An interesting thing about the C language, which they developed in order to use it to write the Unix operating system instead of the PL/I language Multics was developed in. If you look at several of the high-level C-language instructions, they actually map one to one onto machine language instructions in the PDP 11. Of course, that persists now throughout computers; to me it is an everlasting contribution of the Digital Equipment Company.

Zierler:

Dave, I see you had the good sense to achieve tenure and promptly take a sabbatical to Paris. 

Litster:

Oh, yes. 

Zierler:

How did that opportunity in France come about?

Litster:

Well, by then, I knew de Gennes. I was deeply interested in liquid crystals, and the time was coming when I could have a sabbatical. You get one every seven years; so, it was obvious. I applied for a Guggenheim fellowship and got it, so that was good. I do remember, this was all planned. My wife was very excited about it. We didn't have children yet at that time, so a year in Paris sounded great. I had a little surprise for her, though, because she knew I was going to be working with de Gennes, and other people there. This was the same year that de Gennes gave the Loeb lectures I mentioned earlier about the right- and left-handed proteins. There was a reception at Harvard in connection with the Loeb lectures, and my wife and I went to it. She had this mental image of sort of a short, fat, bald man with a mustache. And we went to this party, and Pierre-Gilles was there, about 6'2", charming, wearing a corduroy suit. So, that's how I ended up on that sabbatical. It just seemed like a good thing to do, and we had a great time in Paris for a year. 

Zierler:

Was it your sense—I mean, Paris, of course you're going to have a great time, but in this field, was Paris really the place to be? Was this where most of the really exciting research was happening?

Litster:

Maybe I'm not the person you should ask about that. By that time, I thought that we were doing more exciting stuff at MIT. But the upstanding theorist was de Gennes. Maybe the second-best place to go to was Paris. They had a very strong experimental group at Orsay, and I liked them. It was a lot of fun. We both essentially perfected our French. I had had five years of high school French when I was going to school in Willowdale. 

Zierler:

Because as a Canadian, that mattered.

Litster:

Yeah, but I really couldn't speak it very well. I was able to negotiate our luggage through customs in France, but it was pretty poor French. So, we went religiously, five nights a week, half the time we were there, to the Alliance Française, where they taught foreigners French. Those classes were all in French, because the people in the class might have been Japanese, or who knows. That was good. And at the same time, the people at the lab at Orsay were wonderful, because they refused to speak English with me. I didn't realize until I would meet them later, after the sabbatical was over, and we'd meet at a conference, that they all spoke excellent English. 

Zierler:

The French are unique like that. 

Litster:

Yes. I used to kid my wife about it. In those days, you bought your tickets for the Métro, a little book of ten of them (called a carnet), and you didn't buy those on the train. You could go to the train station and buy them, but all the tobacco shops sold them. So, there was a tabac around the corner from our apartment, and we'd buy our tickets there. My wife went in, after we'd been there for two or three months, and she wanted to buy a booklet of tickets. Of course, the woman behind the counter was a typical French dragon who refused to understand foreigners whose French was imperfect. So, Cheryl said, very clearly so as to be understood, “Madame, je voudrais s’il vous plait, un carnet pour le Métro.”, and the woman replied, in a loud enough voice that everybody turned their heads to see why, “Un carnet pour le Métro. C’est pal mal pour une étrangère, madame.” She had used the wrong preposition.

Zierler:

I'm curious, when you got back to Boston, how did you develop the joint appointment with Harvard and the medical school?

Litster:

That was the Health Science and Technology program. MIT and Harvard had started this program to train doctors who knew more about science than they usually did. I think the HST program was quite good and successful; a graduate of that program was my personal physician until she retired a couple of years ago. Anyway, I was invited to give some lectures. I had built apparatus to control the temperatures of liquid crystals and magnetic materials, quite precisely because we were studying phase transitions. While doing that I had to teach myself a lot about feedback and control theory. The body is full of feedback and control mechanisms, so I gave lectures on that in a hematology course at the Harvard Medical School. I was supposed only to give a lecture or two in the course, but I took the whole course and went to all the lectures because it was interesting. The professor in charge of it was a really nice guy, Bill Beck. He's probably dead now, but I remember I once told him, “Bill, you react to an equation in the same way I react to the sight of blood.” We were each trying to improve ourselves. 

Zierler:

Was it gratifying for you to be working in a field where, at least broadly defined, could have had human health implications?

Litster:

Yes, it was gratifying, but I think the word that would be more appropriate was interesting. 

Zierler:

In what ways? What was interesting to you about it?

Litster:

Mostly because I was learning some things about how the human body worked. 

Zierler:

Right. I want to ask some terminology. I know you become the head of the Division of Atomic Condensed Matter Plasma Physics, and you were on the sciences subcommittee of Condensed Matter for Materials Research at NSF. When does the term “condensed matter” come to the fore beyond solid state, and where would soft matter fit into that as well?

Litster:

Soft matter is a more recent term. I would say that the condensed matter term—I have no idea who first used it—appeared about the time that at least some physicists were interested in liquid crystals. Somebody who made up the term realized that there was interesting physics to be done in materials which were actually not solids. In fact, I don't know if you knew this, if we lived in a two-dimensional world, there wouldn't be any solids. 

Zierler:

Right. And MIT is so large. I'm curious, administratively, how these things work. As head of the Division of Atomic Condensed Matter and Plasma Physics, what does that mean in terms of your day to day? What exactly are you responsible for that would not fall under the purview of the chair of the whole department, for example?

Litster:

Well, I think the people who are those division heads are sort of sub-department heads. It's kind of like the vice president should be in our government, the sub-president. I don't think Dick Cheney fit that role quite perfectly, but I think the current one does better. The physics department had about 90 faculty at one time. It's gotten to be a bit fewer now, but still in many different areas. There are so many things that a department head has to do, but all faculty searches, and preparation of promotion cases, for the Atomic Condensed Matter and Solid-State Physics Division, those were all essentially run by the division. As the head of the division, at least the way I always thought about it, my job was to organize. It wasn't to control. I've always felt that way. When I was VP for research, I had a lot of lab directors reporting to me, and it's kind of interesting when the people who are reporting to you understand much better than you do what it is they're supposed to be doing. It's very educational. 

Zierler:

Right. Dave, I'm curious about the Center for Material Science and Engineering. Were you the founding director of that center?

Litster:

The founding director was Robin Smith, who was a Scot—from the University of Edinburgh. Then, Nicholas Grant, a metallurgist, was the director and then Mildred Dresselhaus, and I was the director after her. I always say that Millie trained me. 

Zierler:

How interdisciplinary was the center as its name might suggest? How much participation were you getting outside of the department of physics? 

Litster:

Most of it. Most of it was materials science, and other disciplines outside of physics. 

Zierler:

Were there any good collaborations, personally, for you, that came as a result of your tenure as director?

Litster:

I think the one that affected me most and was probably most important to me as a physicist was setting up our synchrotron x-ray station at the Brookhaven light source. That was a really important thing, probably mostly for Bob Birgeneau, and me, and our graduate students and post docs, but that was the most direct impact. The CMSE was one of those MRLs, materials research labs, that the government established in response to Sputnik. I don't know how much you looked into their history, but there were about nine or ten of them originally established, and I think there were at that time only about nine or ten universities capable of receiving that kind of support from the government and putting it to good use. Of course, in those days, I was a graduate student, and I was naive. I thought the government was supporting us for the intellectual value of what we were doing. Maybe some in congress thought of it that way, but most of them thought of it so we would have better weapons than the Russians did, which is fine. 

Zierler:

Over this time, the mid to late 1980s, and early 1990s, in what ways were the big questions about liquid crystals changing since when you first got involved? Where was the research at this point?

Litster:

I think by 1980 we had some ideas and had done some interesting things. I just don't remember the dates of all these papers I sent you now, precisely. I can get them from my CV—have you got the sheet in front of you? I can pull it up on my computer. 

Zierler:

I have it. 

Litster:

You have it. Take a look at the first—I didn't give you a complete list. I don't know if you've got them all, but I don't think we'd yet done the smectic stuff, or things like that. Of course, we got the beam line at Brookhaven when Millie was still CMSE director. She squeezed the money to build it out of the MRL budget. That was the important thing about all of those interdisciplinary laboratories. They gave the universities money and the freedom to start interesting things. So, almost everything we did came out of that. But even the mission-oriented agencies were like that. I remember how I got my how I got my first research grant—I tell this story from time to time to students, or even young faculty when I want them to feel bad, how I got my first research grant. There was a conference at Potsdam College, which is up in the snow belt, on the south side of Lake Ontario. I was up there giving a talk one winter. I guess it was back when I was just starting as an assistant professor. I gave my talk, and it was like a ten-minute AIP talk, or maybe a bit longer. I don't remember. Anyway, I do remember at the end of my talk I walked back into the audience and sat down, and then there was a break and we kind of all got up and wandered around to get coffee and pastries. A guy walked up to me, put out his hand and said, “I'm Bob Morris. I work for the Office of Naval Research, and I want to support your work.” That's the way it was in those days. 

Zierler:

I guess you didn't have too much fill of a director position of centers, because then in 1988 you became director of the [Francis Bitter] National Magnet Laboratory. I'm curious if this was more about the fact that you had proven your administrative mettle, and this was a good transition, or this was an opportunity for you to really get involved in research relating to magnets.

Litster:

It was the former. But let me back up to the CMSE days. I think it was the ‘80s I became director, probably ‘83, of CMSE. Millie Dresselhaus was ready to move on. She wanted to do something else. By then, it was sort of obvious that I was the person to pick for the next director. So, I was picked. I also knew things were changing, because the NSF had gotten into the current NSF mode. It seeks to maximize the entropy of its research portfolio. In the early days, MIT, Stanford, and other places like that, got the research money because they would do good things with it. The other universities, the best they could say was, “Well, if you give it to us, we would do good things, too.” Eventually, there was a big thing between Senator Fulbright, Senator Saltonstall and some others about this whole business with the NSF, that it wasn't spreading the money around evenly. That it was unfair. That was having more and more effect, so the CMSE was getting money from NSF, which other universities would like to have. The other thing that was happening was that the faculty who were getting some of their research support through the CMSE were getting kind of comfortable. They sort of assumed that MRL money would keep coming, so they didn't have to break their neck doing things. This reminds me of another story, which I'll tell you, and then we can get back to this one if you want. When I was VP for research, people always wanted to come and talk to the president of MIT and learn what MIT's secret was. President Chuck Vest sometimes didn't want to talk to them. So, he would send them to see me. I was getting a little tired of it too, but I enjoyed talking to them. I couldn't resist giving them a hard time at first, so I would start to say the secret of MIT is you've got to hire good people for your faculty. Of course, they knew their university hadn't done that. That made them feel bad, but then I would cheer them up and say that's not the real reason. The real reason is what I call creative insecurity. MIT lives in a culture of wanting people to be just a little bit insecure, but not too insecure. If they're too insecure, they'll worry about the fact that they're insecure. If they're only a little insecure, it keeps them on their edge, and all kinds of things happen—the way MIT works, it maintains that. It does it with itself, too. MIT has visiting committees to come in for all their departments, and a few other organizations. Most universities, you look at their physics department, once in a while a dean comes in and says, “Well, I think we should have your department evaluated.” So, maybe every five years they'll put together a committee that comes in and gives a report. Not much happens. At MIT, the visiting committee comes in every other year. A third of the members rotate each time. That means, two thirds of them were there at the last visiting committee, and they remember what you told them. That provides a lot of creative insecurity. 

Zierler:

Right, which can be a good thing. 

Litster:

Yes. It is a good thing. You don't want people to get too comfortable. So, back to the CMSE, I realized that some of the people had gotten too comfortable. When we put together our renewal proposal, it reflected that. There were some new people, and maybe some old people doing new and maybe more interesting things. What they would do is they would take their CMSE support to do their pot boilers, and then if they had a new idea that sounded exciting, they would go out and apply for a grant to get more money to do that. So, I fixed that. The NSF appreciated that I had fixed that, and our budget went up by 40% that next year. Now, back to the Magnet Lab. The Magnet Lab was too far separated from the physics department, in my view.

Zierler:

I assume so. In case I missed some aspect of your research that was magnet related, but that's what I figured. 

Litster:

No, it was different. I'll tell you another story. When I was an assistant professor, I was walking down the infinite corridor one day between classes. There was a crowd of people, and walking towards me was Ben Lax, who was the director of the Magnet Lab at the time. He sort of stepped in front of me. We were walking towards each other, and he stopped, and put his finger in my chest and said, “I'm Ben Lax.” And I said, “Yes, I know who you are.” He said, “You seem like a smart young man. You should come over to the Magnet Lab and work on my ideas.” He filled the place up with people who took that offer. So, the Magnet Lab was in trouble. It didn't have as much respect as it deserved in the MIT Physics Department, which was already bad news, and the NSF was getting tired with it. Trouble was coming up, and the administration did the typical MIT thing. Find some great person outside the Institute and hire them to come in as director and fix the problems. They were unable to find anybody who wanted to do that. I was director of CMSE, and I had a certain reputation by then. Ken Smith was Vice President of Research. We had a conversation, and I agreed that I would see what I could do at the Magnet Lab. I used to kid Ken after that. I said, “You know why you picked me as the director of the Magnet Lab? I'm the best person you could get.”

Zierler:

Who were the customers for the Magnet Lab? Who was most interested in benefitting from the results that came about from the Lab?

Litster:

Solid-state physicists all around the country. People at Bell Labs, even. The 1998 Nobel Prize in Physics was awarded for work done at the Francis Bitter National Magnet Lab by Horst Störmer and his Bell Labs colleagues. High magnetic fields were and still are quite interesting, what you can do with them.

Zierler:

Did you take this as an opportunity to read up on magnet science?

Litster:

Yes, there was not a ton of stuff to read up on. It wasn't hard because Bob Richardson had done a report, which identified the problems and the opportunities for high field magnetism. I knew Bob, so I talked to him and got some ideas about it. The people who designed and build the high field magnets at the Bitter Lab were arguably the best in the world. We actually wrote a very good proposal for the renewal of the Magnet Lab, but there were other considerations. The NSF by then was under congressional pressure to fund research in a larger variety of universities and there was a larger number of universities doing first-rate research than existed at the time of Sputnik. Congress had not, in my view, provided an appropriate growth in the NSF budget and so the NSF sought to extract significant cost sharing from the universities it was able to support. MIT was not in a position to provide what the NSF felt would be appropriate cost sharing, and so the agency (counter to the peer review recommendations) decided the National Magnet Laboratory should move to Florida. We made quite a fuss at the time, which I think had a beneficial effect. Because of the fuss, the NSF had to provide Florida State sufficient resources so that it could succeed, and it has been doing well. […]

Zierler:

Dave, I'm curious from your involvement with the APS Division for Condensed Matter Physics. From that broad perspective, where was the field at that point in the 1990s? What were some of the newer, broad questions that were being asked at that time?

Litster:

I'm not prepared to answer that question, but I'll see what I can think of off-hand. Let's see, that was 2000. 

Zierler:

You were chair form ‘98 to ‘99, but you were involved from ‘99 to 2000. 

Litster:

Yeah, yeah. I'm trying to think what we were worried about at that time. Well, I think most things in my narrow field had been done, say, two or three years ago, or were continuing and doing well. I think, to my mind, the biggest new thing was that more physicists were branching out—from time to time, physicists have turned themselves into bio-physicists, and things like that. A lot of them made some rather nice contributions, but they were isolated people. I think it was becoming more popular. To me, that seemed like the—if you had asked me at the time what seems like the most interesting new frontier, I'd have picked that one. I'm trying to remember what got us excited at the NRC panel. There were probably a lot of political things I've forgotten now. 

Zierler:

Probably all for the better. Back at MIT, with regard to your tenure as Vice President for Research, and Dean for Research in the 1990s, I'm curious, administratively, what were the kind of issues that were presented to you, and how did you funnel that up the chain at MIT all the way to the top?

Litster:

Well, it didn't have that far to go because my boss was the provost, and his boss was the president. We all talked to each other. It depended on the issue. The part that was sort of in my job description was probably that MIT has a lot of these interdisciplinary research labs. It's got a lot of people who call themselves a center. Any MIT professor or secretary can create letterhead and call themselves a center. But there was the CMSE, there was the Magnet Lab, there was the Research Laboratory for Electronics. A lot of significant labs and centers. I seem to recall that about eighteen of those reported to me. We had this organization that used to be the Department of Nutrition and Food Science, but once Campbell Soup stopped supporting MIT, it had kind of faded away, but there were still faculty around. Then, there was toxicology, and then there was brain and cognitive science. None of these were really solid departments like physics or chemistry or electrical engineering. So, getting those things straightened out was an issue. That involved deans and department heads. Phil Sharp was involved in a lot, and I think those turned out pretty well. Another thing which, thankfully, didn't pop up all that often was that academic misconduct was part of my portfolio. That didn't necessarily take a lot of time, but it took a lot of attention. It was one of the things I really felt had to be done carefully and properly. 

Zierler:

This position gives you a wide-range view of MIT, and I'm sure that was one of the lesser pleasant aspects of the work. 

Litster:

Yes. I mean, if you asked me would I do it over again? In some sense, it was sort of a public service that I did to MIT. I felt I owed it. But also, it was very educational. I learned a lot about a lot of different fields, and I met a ton of really nice and interesting people. I met a few who were—I like what Will Rogers said, “I've never met a person I didn't like, but I have met a few I didn't respect.” I remember right after the first Gulf War—probably better than other issues because I had just become VP for research. An academic misconduct issue came up in an interesting way. It turned out that one of our faculty had gone to Chuck Vest, MIT President, and accused one of his colleagues of academic misconduct. So, Chuck came to me and said, “This is your portfolio. You deal with it.” It was about the Gulf War. How old were you at the first Gulf War?

Zierler:

I would have been 11 years old. 

Litster:

You probably were not paying a lot of attention to it, but you probably were watching the TV news at night. The Iraqis were firing Scud missiles at Israel, and the US had put patriot missiles into Israel to shoot down the Scuds. A conflict arose between two faculty members. One of them had video copies of everything that was broadcast on TV. They showed several events when a Scud was coming, and a patriot missile went up, and poof, the Scud was blown up. Even though it was only 525-line TV, he analyzed it very carefully. The patriots, of course, were highly spoken of by the president, and everybody on down, during this war period. My colleague was a guy who believed the Scuds were overrated. They weren't as good as the government (or Raytheon) said they were. He was invited to give testimony in Congress, and then another colleague was invited to give testimony that the scuds were working fine. So, the first colleague who describes himself as a street fighter, and intellectually he is, although I like him very much, accused the second one of academic misconduct because he falsely testified before Congress. When Chuck Vest said, “You fix it,” I went to the first guy, and I said, “Can I borrow your VCR tapes? I want to look at the videos.” I looked at the videos carefully, and then I gave them back to him, and I went to Chuck and said, “Well, I think so-and-so is right. I don't think the patriot missiles were all that hot. I think the Scuds were breaking up all on their own as they came into the atmosphere. But this is not academic misconduct. This is just a disagreement between two faculty.” That was the end of it. So, it was kind of an interesting academic misconduct case. Of course, the first guy who said the patriot was trash and didn't work was not quite right. It did work; it kept Israel out of the war, and that was the main point. There are always interesting things, even in situations where you may not expect them.

Zierler:

I wonder if you had an appreciation for the fact that MIT, being as large and as important as it is, that your position in this role set a tone for science beyond the confines for the MIT campus—if it reverberated into the broader academic scientific community. 

Litster:

It might have a little bit. I always felt if I ever saw my name in the paper that I'd made a mistake. But, of course, there were a dozen of us who had a similar job in several universities: Harvard, Stanford, Chicago, Cornell, etc. We would meet together and talk, and we had some influence on each other, and occasionally came up with statements about things. I think there were probably a lot of things I didn't do, and that was good, too. You can do a lot of good by not doing something sometimes. There were other things that had a bit of an impact. In fact, it'll lead you into maybe something else, but I'm trying to think what an interesting example might be. It slipped my mind. It was on the tip of my tongue, and it didn't come out. It probably will in a minute. Oh, I remember one thing that was kind of interesting. It actually involves the current president of MIT when he was a professor trying to get money from the Semiconductor Research Council. You probably know about them. 

Zierler:

Sure. 

Litster:

They support research in universities, and we got into a big fight with them. It was all the research universities, actually, over intellectual property. Universities and industry treat it differently. In universities, the inventor is a stakeholder, thanks to the Bayh-Dole Act. In industry, if you invent something, the company owns the patent, and you might get a $200 raise and a certificate to hang on your office wall. So, it's very different. I don't think the industry people understood that. In fact, I know they didn't understand it. Our president-to-be had written a research proposal, and SRC wanted to fund it. It was an important point in his research career, but the SRC said that if an industry funds research at MIT, and something valuable comes out of it, the industry should get it. Our policy is that MIT will own the patent, but the company has the first rights of refusal to use it. They may pay a licensing fee, but it'll be fair, or they can use it without a licensing fee, provided that it's not exclusive; MIT could then license it to other people. If there is licensing income, the faculty member gets a third of it to support his or her personal research. That's before expenses are taken off, and then the expenses come off—filing and other expenses to acquire the patent. What's left gets divided equally between the inventor’s department and the provost. So, that's how MIT treats intellectual property. Stanford taught us how to do that before my time, but most universities do the same or something similar. Thanks to Bayh-Dole, the universities own the IP, and the inventors are stakeholders. So, we said to the SRC, “If Professor Reif invents something and you want to use it. That's fine. We'll make sure that you get to use it. These will be the conditions.” And they said that's fine, but then they said there's such a thing as background intellectual property, which you've probably heard of, too. They didn't pick a specific example like I'm about to, but they said if there's background property that interferes with using this patent, we want the rights for that, too. In other words, if we need to use one of Phil Sharp's patents in order to practice one of Professor Reif's patents, we want you to guarantee that we can do that. But maybe stakeholder Phil Sharp wants to start a company and use it instead. The SRC didn't want to agree to that, so we had that fight, and it ended up as one of those things I said I'd never do. I don't want to see my name on the front page of the Boston Globe, and I never want to go to a meeting at 6am Sunday morning in the Dallas Airport, like people who think they're important feel they have to do. Anyway, there was a meeting of all of our various Vice Presidents of Research, and it was in the Dallas Airport. It was not 6am Sunday morning, but we all went. So, we had this meeting—with Arden Bement as chair. His task was to keep us from beating each other up. There were several people whose names you know: Bob Richardson from Cornell (Nobel prize in physics), John Hennessy (who became president of Stanford). We were all there because we had an interest in this particular problem. Somehow, I don't remember how, I ended up being the spokesman for the universities and making most of the arguments. Maybe because I had thought about it more—I don't know. And we won. They agreed that they now understood intellectual property in universities. So, that was an important thing. It actually made a big change in my life, because about six months later I got a call from Rick Hill, who was the CEO of Novellus Systems. He said, “Do you remember we met in the meeting at the Dallas Airport? I've been thinking we should have an academic on our board, and you're the only one I've met who seemed to have any common sense. Would you like to come out and see our company and meet some of our people?” I said, "\”Well, an invitation like that, how can I refuse?” I spent 12 years on the Novellus board, and that was my second education. I was the chair of the Compensation Committee on the board for ten years dealing with people who were paid three to five to six to eight times as much as I was and setting their salaries. That's educational. 

Zierler:

Dave, your membership to the MIT Nuclear Reactor Safeguards Committee, this is ongoing?

Litster:

Yes.

Zierler:

In what way does this work interface with national policy?

Litster:

Well, I'm not sure that we do national policy, but we certainly interface with the NRC. They watch us like a hawk, and we interface with other research reactors in the country. The main thing that I would put in the category of national policy that we're involved with is low enrichment fuel, because we use highly enriched uranium. But there are certain things we can do in our MIT reactor that the other research reactors in our country, that the DOE reactors can't do. So, we do them and we have a research support from Idaho (INEL) and other DOE sources. The main thing the Safeguards Committee worries about is when we do experiments, including many where things go in the reactor core to be radiated and studied, we want to make sure that not more than a few radioactive atoms get loose in downtown Cambridge. 

Zierler:

You've had a good record, a good run.

Litster:

We've had a good record, yes. 

Zierler:

Dave, now that we've brought your work up to the present, I want to ask you for the final part of our discussion, a few broadly retrospective questions, and ask you to assess your overall career, and then a final question that will have an element of future-facing. The first is, In your long career in condensed matter and related fields—and you can answer both in terms of your individual capacity and as a representative of the field—what are some of the major differences in the kinds of questions that were asked at the beginning of your career and that have been asked in more recent years, both in terms of the fundamental science that may not have been well understood at the time, but is really, to the extent that we're capable of these things, really truly understood now, and what are some things where there remains much fundamental work to be done, even 40 or 50 years after this work was started?

Litster:

Hmm. Well, the theme of it you can get out of the things I said earlier, which is trying to understand phase transitions, the role of geometry in determining the kinds of phases that you can have, or you can't have. I think there's been pretty significant progress in the things we were working on. I'm speaking for the whole field now. I'm not just speaking for myself and my friends at MIT. I think there's not a lot of activity of the same kind that we were doing going on now because many of these questions have been answered and understood. I think the major thing in that same theme, which to my mind remains to be understood much better than it is, is the whole question of melting. I don't think we understand that really at a depth much beyond the ideas that Lindemann had in the 1930s. So, I think that's a narrow part. Physicists have become much broader in their interests than they were. I'm talking about condensed matter physicists. There's just tons of exciting stuff going on in other areas: astronomy, exoplanets, cosmology, dark energy, dark matter, etc. So, I think if I were to ask what the major areas in condensed matter are that one might be able to attack, I would move more in the direction of interfaces with the life sciences, and human health. They're complicated. Another thing which is sort of an advantage for us is back when I was a graduate student, there were assistant professors starting to work on these things. The Mandarins didn't think they were interesting. They thought they were solved problems. They're atoms, and maybe molecules, and that’s well enough understood. Phil Anderson has fought back, and I think won the battle with those guys. He wrote this paper, “More is different.” It's true. I think things are at a stage when you talk about the life sciences, and biology, and related things, that's a significant extension of “More is different.” But so much has come. I'm really impressed with what the life sciences are doing. The fact that probably within a year of this virus inventing itself, they're going to have vaccines for it. I've been reading some of the papers coming out of Oxford and other places lately about the work they're doing. It's the coronavirus, and the antibodies, and how they bind to it, and related things. Even 20 years ago it would have been science fiction to think about that. So, a lot of really significant stuff for the human race is coming up. And then, of course, there are other fields. You probably read The Selfish Gene by Richard Dawkins, who I think is a bit pompous, but he uses the English language very well. That was an outstanding book, but people in that area have struggled with altruism. How do selfish genes become altruistic? Edward Wilson is the man who I think has an answer to that, although I don't think it's as widely accepted as I accept it, and maybe I'm wrong. He says once these genes have made creatures that interact with each other and have a society, then it's a whole new ballgame. That's how you get altruism. The selfish creatures can interact in an altruistic way and improve the society, which will improve life for them. That's basically why I think, on reading Wilson's papers, he’s figured that out. He did it with ants. 

Zierler:

Dave, the other broad question I wanted to ask you is, it's hard to quantify these things, but your achievements in the service and administrative realm are quite significant, right there with your research achievements. I want to ask broadly, in what ways have you drawn on your expertise and background as a physicist to help you in the largely sociological realms that are committee participation and leadership, and positions of leadership in both the academic and private sector? In what ways has being a scientist helped you navigate all of those tricky issues that come up just in dealing with people?

Litster:

Well, I can give you probably the same answer phrased in several different ways. One of them is a phrase from my thesis supervisor, George Benedek, who grew up in New York where he picked up this—and you've probably heard it too—"you learn to tell shit from Shinola.” To put it more politely, I've always said to people, to my students in particular, that the most important thing you learn when getting a PhD is how to solve problems. If you can do that, it's transferable. I'll give you an example from our friend Bob Birgeneau. I mentioned that Bob is always the guy who, when we were doing experiments, was the first one to figure out what the data meant. So, when several of the MIT women faculty walked into his office when he was Dean of Science, and presented him with some data, it took him ten seconds to figure out what the problem was and how to solve it. Well, not necessarily how to solve it, because it's a hard problem to solve, but he understood well what it was. So, I think that's an important thing that you get out of being a scientist. You just listen to newspaper reporters and politicians talking, and so on, and you can see that's a kind of mental discipline that most of these people don't have. They have others. My theorem is that there are many ways you can be smart. I go back to this, which again, you may not remember. There was a time when the universities got into trouble with politicians about overhead rates. Don Kennedy was the president of Stanford at the time, and he was called to testify to Congress about all these overhead charges to everything. He gave his testimony, and you could see he hadn't really thought about it or hadn't prepared about it. You could sort of read between the lines that he had this attitude: I'm a really smart scientist and a university president. I can deal with these hicks in Congress. He discovered, to his humiliation, that these hicks in Congress could think about the political issues much better than he could. So, there's a range of skills. 

Zierler:

Dave, for my last question, I want to ask you, based on your decades in the field, your ongoing engagement with the field, what are some of the things that you're personally excited about in terms of where the research and discovery is headed into the future?

Litster:

Well, first of all, I don't think I'd have used the word engagement with respect to the field. I would say interest, more than engagement. I'm retired, and I'm enjoying—I think even as a university professor, it's one of the benefits of the job that you have a lot of time that you can spend any way you want. So, I'm just reading more broadly. Some of what I was doing the last two or three days, actually, is in the house we have here in California. We had Tesla install solar panels on the roof and battery storage to help with the electricity. They installed them in May, and by the way, if you're interested in solar panels, which I don't know why you would be in New York, but the Tesla product—this is my engineering point of view—is terrific for a household with sunshine. It's the best you can do right now; the Tesla power walls are apart. Anyway, what I just did is this—you can go to the Department of Energy, and you can pick up software (called PVWatts) that will calculate for you where the sun is in the sky at any time of any day in the year. So, I've used that to put together a program which predicts what my solar cells should be doing whenever it is sunny. Tesla provides a nice app which plots (in five-minute intervals) during the day how much solar power you're actually generating, what your house consumption is, how much you're putting in the batteries, and how much you are sending to the power company. So, I can predict what Tesla should measure with this model I built. It's not perfect. It's probably accurate within five or ten percent. So, I can predict what's going to happen on September 21 or December 21. I just did those two dates yesterday. It's fun. I sort of enjoy putting together equipment to control the lights in the house, and computer programs to run them, and so on. Although, I will say there's a difference between computer programming and research. The way I used to explain this to my students, they're both solving problems. But with a computer, you're solving a problem that somebody else has already solved, but you have to solve it again because they didn't document it sufficiently. Whereas, with scientific research, you're trying to solve a problem that only God knows the answer to. 

Zierler:

Well, Dave, it's been an absolute pleasure speaking with you. I'm so glad that we connected through your good and dear friend Bob Birgeneau. For so many reasons, this is going to be quite an important and engaging interview for our collection. So, I really want to thank you for spending the time with me. 

Litster:

Well, thank you. You do a good job and Bob had me read—since I last talked to you—a thing Berkeley put together for him. After I read it, I said—I don't know if you've read it. 

Zierler:

I did. 

Litster:

I told Bob, I said, “That's very nice. You treated your colleagues a lot better than we treated you at the time.”

Zierler:

That's one of the many reasons that makes him such a special guy.